diff mbox

[v3,2/2] posix: Implement preadv2 and pwritev2

Message ID 1493901791-13438-2-git-send-email-adhemerval.zanella@linaro.org
State Dropped
Headers show

Commit Message

Adhemerval Zanella May 4, 2017, 12:43 p.m. UTC
Change from previous version:

   * Add unsupported flag check for Linux implementation.

   * Unsupported/invalid flags now return EOPNOTSUPP instead of
     EINVAL.

   * Add comment about preadv2 and pwritev2 support on kernel-features.h.

   * Add NEWS entry.

   * Fix typo in documentation.
        
--

This patch adds support of preadv2 and pwritev2 which are similar to
preadv/pwritev but adds an extra flag argument.  As for preadv/pwritev
both interfaces are added a non-standard standard GNU API.

On default 'posix' implementation trying to emulate the Linux supported
flags is troublesome:

   * We can not temporary change the file state of the O_DSYNC and O_SYNC
     flags to emulate RWF_{D}SYNC (attempts to change the state of using
     fcntl are silently ignored).

   * IOCB_HIPRI requires the file opened in O_DIRECT and uses an internal
     semantic not provided by any other flag (O_NONBLOCK for instance).

So default sysdeps/posix implementations fails with EINVAL for any non
supported flag (which are none currently) calls generic preadv/pwritev.
Basically, it supports only preadv2 called as preadv (with flags sets
to 0).

The Linux one uses the preadv2/pwritev2 syscall if defined, otherwise it
call preadv/writev.  Instead of using the previous __ASSUME_* to
unconditionally issue the syscall (and avoid building the fallback routine),
it call pread/write if the preadv2/pwritev2 syscalls fails.  The idea
is just avoid adding another __ASSUME_* and checking each architecture
on every kernel bump and simplify code conditionals.

Checked on x86_64-linux-gnu and on i686-linux-gnu and a check with
run-built-tests=no on aarch64-linux-gnu, alpha-linux-gnu, arm-linux-gnueabihf,
ia64-linux-gnu, m68k-linux-gnu, microblaze-linux-gnu, mips{64,64n32}-linux-gnu,
nios2-linux-gnu, powerpc{64,64le}-linux-gnu, s390{x}-linux-gnu,
sparc{64,v9}-linux-gnu, tile{gx,pro}-linux-gnu, and sh4-linux-gnu (all using
gcc 6.3).

	* NEWS: Add note about pwritev2 and preadv2 inclusion.
	* misc/Makefile (routines): Add preadv2, preadv64v2, pwritev2, and
	pwritev64v2.
	(tests): Add tst-preadvwritev2 and tst-preadvwritev64v2.
	* misc/Versions (GLIBC_2.26): Add preadv2, preadv64v2, pwritev2, and
	pwritev64v2.
	* misc/preadv2.c: New file.
	* misc/preadv64v2.c: Likewise.
	* misc/pwritev2.c: Likewise.
	* misc/pwritev64v2.c: Likewise.
	* misc/tst-preadvwritev2.c: Likewise.
	* misc/tst-preadvwritev64v2.c: Likewise.
	* manual/llio.texi: Add preadv2 and pwritev2 documentation.
	* misc/sys/uio.h [__USE_GNU && !__USE_FILE_OFFSET64] (preadv2): New
	prototype.
	[__USE_GNU && !__USE_FILE_OFFSET64] (pwritev2):	Likewise.
	[__USE_GNU && __USE_FILE_OFFSET64] (preadv64v2): Likewise.
	[__USE_GNU && __USE_FILE_OFFSET64] (pwritev64v2): Likewise.
	* misc/tst-preadvwritev-common.c (PREADV): Define if not defined.
	(PWRITEV): Likewise.
	(do_test_with_offset): Use PREADV and PWRITEV macros and check for
	ENOSYS.
	* nptl/tst-cancel4.c (tf_pwritev2): New test.
	(tf_preadv2): Likewise.
	(tf_fsync): Add tf_pwritev2 and tf_preadv2.
	* sysdeps/posix/preadv2.c: Likewise.
	* sysdeps/posix/preadv64v2.c: Likewise.
	* sysdeps/posix/pwritev2.c: Likewise.
	* sysdeps/posix/pwritev64v2.c: Likewise.
	* sysdeps/unix/sysv/linux/kernel-features.h: Add comment for syscall
	support in kernel.
	* sysdeps/unix/sysv/linux/preadv2.c: Likewise.
	* sysdeps/unix/sysv/linux/preadv64v2.c: Likewise.
	* sysdeps/unix/sysv/linux/pwritev2.c: Likewise.
	* sysdeps/unix/sysv/linux/pwritev64v2.c: Likewise.
	* sysdeps/unix/sysv/linux/preadv.c (preadv): Add libc_hidden_def.
	* sysdeps/unix/sysv/linux/preadv64.c (preadv64): Likewise.
	* sysdeps/unix/sysv/linux/pwritev.c (pwritev): Likewise.
	* sysdeps/unix/sysv/linux/pwritev64.c (pwritev64): Likewise.
	* sysdeps/unix/sysv/linux/bits/uio.h: Add supported preadv2/pwritev2
	support flags on Linux.
	* sysdeps/unix/sysv/linux/aarch64/libc.abilist (GLIBC_2.26): Add
	preadv2, preadv64v2, pwritev2, pwritev64v2.
	* sysdeps/unix/sysv/linux/alpha/libc.abilist (GLIBC_2.26): Likewise.
	* sysdeps/unix/sysv/linux/arm/libc.abilist (GLIBC_2.26): Likewise.
	* sysdeps/unix/sysv/linux/hppa/libc.abilist (GLIBC_2.26): Likewise.
	* sysdeps/unix/sysv/linux/i386/libc.abilist (GLIBC_2.26): Likewise.
	* sysdeps/unix/sysv/linux/ia64/libc.abilist (GLIBC_2.26): Likewise.
	* sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist (GLIBC_2.26):
	Likewise.
	* sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist (GLIBC_2.26):
	Likewise.
	* sysdeps/unix/sysv/linux/microblaze/libc.abilist (GLIBC_2.26):
	Likewise.
	* sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist (GLIBC_2.26):
	Likewise.
	* sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist (GLIBC_2.26):
	Likewise.
	* sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist (GLIBC_2.26):
	Likewise.
	* sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist (GLIBC_2.26):
	Likewise.
	* sysdeps/unix/sysv/linux/nios2/libc.abilist (GLIBC_2.26): Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
	(GLIBC_2.26): Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
	(GLIBC_2.26): Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist (GLIBC_2.26):
	Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist
	(GLIBC_2.26): Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist (GLIBC_2.26):
	Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist (GLIBC_2.26):
	Likewise.
	* sysdeps/unix/sysv/linux/sh/libc.abilist (GLIBC_2.26): Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist (GLIBC_2.26):
	Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist (GLIBC_2.26):
	Likewise.
	* sysdeps/sysv/linux/tile/tilegx/tilegx32/libc.abilist (GLIBC_2.26):
	Likewise.
	* sysdeps/sysv/linux/tile/tilegx/tilegx64/libc.abilist (GLIBC_2.26):
	Likewise.
	* sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist (GLIBC_2.26):
	Likewise.
	* sysdeps/unix/sysv/linux/x86_64/64/libc.abilist (GLIBC_2.26):
	Likewise.
	* sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist (GLIBC_2.26):
	Likewise.
---
 ChangeLog                                          |  91 +++++++++++++++++
 NEWS                                               |   7 ++
 include/sys/uio.h                                  |   6 ++
 manual/llio.texi                                   | 109 +++++++++++++++++++++
 misc/Makefile                                      |   5 +-
 misc/Versions                                      |   3 +
 misc/preadv2.c                                     |  30 ++++++
 misc/preadv64v2.c                                  |  30 ++++++
 misc/pwritev2.c                                    |  30 ++++++
 misc/pwritev64v2.c                                 |  30 ++++++
 misc/sys/uio.h                                     |  41 ++++++++
 misc/tst-preadvwritev-common.c                     |  19 +++-
 misc/tst-preadvwritev2.c                           |  31 ++++++
 misc/tst-preadvwritev64v2.c                        |  33 +++++++
 nptl/tst-cancel4.c                                 |  71 ++++++++++++++
 sysdeps/posix/preadv2.c                            |  38 +++++++
 sysdeps/posix/preadv64v2.c                         |  37 +++++++
 sysdeps/posix/pwritev2.c                           |  38 +++++++
 sysdeps/posix/pwritev64v2.c                        |  38 +++++++
 sysdeps/unix/sysv/linux/aarch64/libc.abilist       |   5 +
 sysdeps/unix/sysv/linux/alpha/libc.abilist         |   5 +
 sysdeps/unix/sysv/linux/arm/libc.abilist           |   5 +
 sysdeps/unix/sysv/linux/bits/uio.h                 |   6 ++
 sysdeps/unix/sysv/linux/hppa/libc.abilist          |   5 +
 sysdeps/unix/sysv/linux/i386/libc.abilist          |   5 +
 sysdeps/unix/sysv/linux/ia64/libc.abilist          |   5 +
 sysdeps/unix/sysv/linux/kernel-features.h          |   5 +
 sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist |   5 +
 sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist   |   5 +
 sysdeps/unix/sysv/linux/microblaze/libc.abilist    |   5 +
 .../unix/sysv/linux/mips/mips32/fpu/libc.abilist   |   5 +
 .../unix/sysv/linux/mips/mips32/nofpu/libc.abilist |   5 +
 .../unix/sysv/linux/mips/mips64/n32/libc.abilist   |   5 +
 .../unix/sysv/linux/mips/mips64/n64/libc.abilist   |   5 +
 sysdeps/unix/sysv/linux/nios2/libc.abilist         |   5 +
 .../sysv/linux/powerpc/powerpc32/fpu/libc.abilist  |   5 +
 .../linux/powerpc/powerpc32/nofpu/libc.abilist     |   5 +
 .../sysv/linux/powerpc/powerpc64/libc-le.abilist   |   5 +
 .../unix/sysv/linux/powerpc/powerpc64/libc.abilist |   5 +
 sysdeps/unix/sysv/linux/preadv.c                   |   2 +
 sysdeps/unix/sysv/linux/preadv2.c                  |  55 +++++++++++
 sysdeps/unix/sysv/linux/preadv64.c                 |   2 +
 sysdeps/unix/sysv/linux/preadv64v2.c               |  55 +++++++++++
 sysdeps/unix/sysv/linux/pwrite64.c                 |   1 +
 sysdeps/unix/sysv/linux/pwritev.c                  |   2 +
 sysdeps/unix/sysv/linux/pwritev2.c                 |  51 ++++++++++
 sysdeps/unix/sysv/linux/pwritev64.c                |   2 +
 sysdeps/unix/sysv/linux/pwritev64v2.c              |  55 +++++++++++
 sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist  |   5 +
 sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist  |   5 +
 sysdeps/unix/sysv/linux/sh/libc.abilist            |   5 +
 sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist |   5 +
 sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist |   5 +
 .../sysv/linux/tile/tilegx/tilegx32/libc.abilist   |   5 +
 .../sysv/linux/tile/tilegx/tilegx64/libc.abilist   |   5 +
 sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist  |   5 +
 sysdeps/unix/sysv/linux/x86_64/64/libc.abilist     |   5 +
 sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist    |   5 +
 58 files changed, 1058 insertions(+), 5 deletions(-)
 create mode 100644 misc/preadv2.c
 create mode 100644 misc/preadv64v2.c
 create mode 100644 misc/pwritev2.c
 create mode 100644 misc/pwritev64v2.c
 create mode 100644 misc/tst-preadvwritev2.c
 create mode 100644 misc/tst-preadvwritev64v2.c
 create mode 100644 sysdeps/posix/preadv2.c
 create mode 100644 sysdeps/posix/preadv64v2.c
 create mode 100644 sysdeps/posix/pwritev2.c
 create mode 100644 sysdeps/posix/pwritev64v2.c
 create mode 100644 sysdeps/unix/sysv/linux/preadv2.c
 create mode 100644 sysdeps/unix/sysv/linux/preadv64v2.c
 create mode 100644 sysdeps/unix/sysv/linux/pwritev2.c
 create mode 100644 sysdeps/unix/sysv/linux/pwritev64v2.c

Comments

Adhemerval Zanella May 11, 2017, 7:01 p.m. UTC | #1
Ping.

On 04/05/2017 09:43, Adhemerval Zanella wrote:
> Change from previous version:
> 
>    * Add unsupported flag check for Linux implementation.
> 
>    * Unsupported/invalid flags now return EOPNOTSUPP instead of
>      EINVAL.
> 
>    * Add comment about preadv2 and pwritev2 support on kernel-features.h.
> 
>    * Add NEWS entry.
> 
>    * Fix typo in documentation.
>         
> --
> 
> This patch adds support of preadv2 and pwritev2 which are similar to
> preadv/pwritev but adds an extra flag argument.  As for preadv/pwritev
> both interfaces are added a non-standard standard GNU API.
> 
> On default 'posix' implementation trying to emulate the Linux supported
> flags is troublesome:
> 
>    * We can not temporary change the file state of the O_DSYNC and O_SYNC
>      flags to emulate RWF_{D}SYNC (attempts to change the state of using
>      fcntl are silently ignored).
> 
>    * IOCB_HIPRI requires the file opened in O_DIRECT and uses an internal
>      semantic not provided by any other flag (O_NONBLOCK for instance).
> 
> So default sysdeps/posix implementations fails with EINVAL for any non
> supported flag (which are none currently) calls generic preadv/pwritev.
> Basically, it supports only preadv2 called as preadv (with flags sets
> to 0).
> 
> The Linux one uses the preadv2/pwritev2 syscall if defined, otherwise it
> call preadv/writev.  Instead of using the previous __ASSUME_* to
> unconditionally issue the syscall (and avoid building the fallback routine),
> it call pread/write if the preadv2/pwritev2 syscalls fails.  The idea
> is just avoid adding another __ASSUME_* and checking each architecture
> on every kernel bump and simplify code conditionals.
> 
> Checked on x86_64-linux-gnu and on i686-linux-gnu and a check with
> run-built-tests=no on aarch64-linux-gnu, alpha-linux-gnu, arm-linux-gnueabihf,
> ia64-linux-gnu, m68k-linux-gnu, microblaze-linux-gnu, mips{64,64n32}-linux-gnu,
> nios2-linux-gnu, powerpc{64,64le}-linux-gnu, s390{x}-linux-gnu,
> sparc{64,v9}-linux-gnu, tile{gx,pro}-linux-gnu, and sh4-linux-gnu (all using
> gcc 6.3).
> 
> 	* NEWS: Add note about pwritev2 and preadv2 inclusion.
> 	* misc/Makefile (routines): Add preadv2, preadv64v2, pwritev2, and
> 	pwritev64v2.
> 	(tests): Add tst-preadvwritev2 and tst-preadvwritev64v2.
> 	* misc/Versions (GLIBC_2.26): Add preadv2, preadv64v2, pwritev2, and
> 	pwritev64v2.
> 	* misc/preadv2.c: New file.
> 	* misc/preadv64v2.c: Likewise.
> 	* misc/pwritev2.c: Likewise.
> 	* misc/pwritev64v2.c: Likewise.
> 	* misc/tst-preadvwritev2.c: Likewise.
> 	* misc/tst-preadvwritev64v2.c: Likewise.
> 	* manual/llio.texi: Add preadv2 and pwritev2 documentation.
> 	* misc/sys/uio.h [__USE_GNU && !__USE_FILE_OFFSET64] (preadv2): New
> 	prototype.
> 	[__USE_GNU && !__USE_FILE_OFFSET64] (pwritev2):	Likewise.
> 	[__USE_GNU && __USE_FILE_OFFSET64] (preadv64v2): Likewise.
> 	[__USE_GNU && __USE_FILE_OFFSET64] (pwritev64v2): Likewise.
> 	* misc/tst-preadvwritev-common.c (PREADV): Define if not defined.
> 	(PWRITEV): Likewise.
> 	(do_test_with_offset): Use PREADV and PWRITEV macros and check for
> 	ENOSYS.
> 	* nptl/tst-cancel4.c (tf_pwritev2): New test.
> 	(tf_preadv2): Likewise.
> 	(tf_fsync): Add tf_pwritev2 and tf_preadv2.
> 	* sysdeps/posix/preadv2.c: Likewise.
> 	* sysdeps/posix/preadv64v2.c: Likewise.
> 	* sysdeps/posix/pwritev2.c: Likewise.
> 	* sysdeps/posix/pwritev64v2.c: Likewise.
> 	* sysdeps/unix/sysv/linux/kernel-features.h: Add comment for syscall
> 	support in kernel.
> 	* sysdeps/unix/sysv/linux/preadv2.c: Likewise.
> 	* sysdeps/unix/sysv/linux/preadv64v2.c: Likewise.
> 	* sysdeps/unix/sysv/linux/pwritev2.c: Likewise.
> 	* sysdeps/unix/sysv/linux/pwritev64v2.c: Likewise.
> 	* sysdeps/unix/sysv/linux/preadv.c (preadv): Add libc_hidden_def.
> 	* sysdeps/unix/sysv/linux/preadv64.c (preadv64): Likewise.
> 	* sysdeps/unix/sysv/linux/pwritev.c (pwritev): Likewise.
> 	* sysdeps/unix/sysv/linux/pwritev64.c (pwritev64): Likewise.
> 	* sysdeps/unix/sysv/linux/bits/uio.h: Add supported preadv2/pwritev2
> 	support flags on Linux.
> 	* sysdeps/unix/sysv/linux/aarch64/libc.abilist (GLIBC_2.26): Add
> 	preadv2, preadv64v2, pwritev2, pwritev64v2.
> 	* sysdeps/unix/sysv/linux/alpha/libc.abilist (GLIBC_2.26): Likewise.
> 	* sysdeps/unix/sysv/linux/arm/libc.abilist (GLIBC_2.26): Likewise.
> 	* sysdeps/unix/sysv/linux/hppa/libc.abilist (GLIBC_2.26): Likewise.
> 	* sysdeps/unix/sysv/linux/i386/libc.abilist (GLIBC_2.26): Likewise.
> 	* sysdeps/unix/sysv/linux/ia64/libc.abilist (GLIBC_2.26): Likewise.
> 	* sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist (GLIBC_2.26):
> 	Likewise.
> 	* sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist (GLIBC_2.26):
> 	Likewise.
> 	* sysdeps/unix/sysv/linux/microblaze/libc.abilist (GLIBC_2.26):
> 	Likewise.
> 	* sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist (GLIBC_2.26):
> 	Likewise.
> 	* sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist (GLIBC_2.26):
> 	Likewise.
> 	* sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist (GLIBC_2.26):
> 	Likewise.
> 	* sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist (GLIBC_2.26):
> 	Likewise.
> 	* sysdeps/unix/sysv/linux/nios2/libc.abilist (GLIBC_2.26): Likewise.
> 	* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
> 	(GLIBC_2.26): Likewise.
> 	* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
> 	(GLIBC_2.26): Likewise.
> 	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist (GLIBC_2.26):
> 	Likewise.
> 	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist
> 	(GLIBC_2.26): Likewise.
> 	* sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist (GLIBC_2.26):
> 	Likewise.
> 	* sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist (GLIBC_2.26):
> 	Likewise.
> 	* sysdeps/unix/sysv/linux/sh/libc.abilist (GLIBC_2.26): Likewise.
> 	* sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist (GLIBC_2.26):
> 	Likewise.
> 	* sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist (GLIBC_2.26):
> 	Likewise.
> 	* sysdeps/sysv/linux/tile/tilegx/tilegx32/libc.abilist (GLIBC_2.26):
> 	Likewise.
> 	* sysdeps/sysv/linux/tile/tilegx/tilegx64/libc.abilist (GLIBC_2.26):
> 	Likewise.
> 	* sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist (GLIBC_2.26):
> 	Likewise.
> 	* sysdeps/unix/sysv/linux/x86_64/64/libc.abilist (GLIBC_2.26):
> 	Likewise.
> 	* sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist (GLIBC_2.26):
> 	Likewise.
> ---
>  ChangeLog                                          |  91 +++++++++++++++++
>  NEWS                                               |   7 ++
>  include/sys/uio.h                                  |   6 ++
>  manual/llio.texi                                   | 109 +++++++++++++++++++++
>  misc/Makefile                                      |   5 +-
>  misc/Versions                                      |   3 +
>  misc/preadv2.c                                     |  30 ++++++
>  misc/preadv64v2.c                                  |  30 ++++++
>  misc/pwritev2.c                                    |  30 ++++++
>  misc/pwritev64v2.c                                 |  30 ++++++
>  misc/sys/uio.h                                     |  41 ++++++++
>  misc/tst-preadvwritev-common.c                     |  19 +++-
>  misc/tst-preadvwritev2.c                           |  31 ++++++
>  misc/tst-preadvwritev64v2.c                        |  33 +++++++
>  nptl/tst-cancel4.c                                 |  71 ++++++++++++++
>  sysdeps/posix/preadv2.c                            |  38 +++++++
>  sysdeps/posix/preadv64v2.c                         |  37 +++++++
>  sysdeps/posix/pwritev2.c                           |  38 +++++++
>  sysdeps/posix/pwritev64v2.c                        |  38 +++++++
>  sysdeps/unix/sysv/linux/aarch64/libc.abilist       |   5 +
>  sysdeps/unix/sysv/linux/alpha/libc.abilist         |   5 +
>  sysdeps/unix/sysv/linux/arm/libc.abilist           |   5 +
>  sysdeps/unix/sysv/linux/bits/uio.h                 |   6 ++
>  sysdeps/unix/sysv/linux/hppa/libc.abilist          |   5 +
>  sysdeps/unix/sysv/linux/i386/libc.abilist          |   5 +
>  sysdeps/unix/sysv/linux/ia64/libc.abilist          |   5 +
>  sysdeps/unix/sysv/linux/kernel-features.h          |   5 +
>  sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist |   5 +
>  sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist   |   5 +
>  sysdeps/unix/sysv/linux/microblaze/libc.abilist    |   5 +
>  .../unix/sysv/linux/mips/mips32/fpu/libc.abilist   |   5 +
>  .../unix/sysv/linux/mips/mips32/nofpu/libc.abilist |   5 +
>  .../unix/sysv/linux/mips/mips64/n32/libc.abilist   |   5 +
>  .../unix/sysv/linux/mips/mips64/n64/libc.abilist   |   5 +
>  sysdeps/unix/sysv/linux/nios2/libc.abilist         |   5 +
>  .../sysv/linux/powerpc/powerpc32/fpu/libc.abilist  |   5 +
>  .../linux/powerpc/powerpc32/nofpu/libc.abilist     |   5 +
>  .../sysv/linux/powerpc/powerpc64/libc-le.abilist   |   5 +
>  .../unix/sysv/linux/powerpc/powerpc64/libc.abilist |   5 +
>  sysdeps/unix/sysv/linux/preadv.c                   |   2 +
>  sysdeps/unix/sysv/linux/preadv2.c                  |  55 +++++++++++
>  sysdeps/unix/sysv/linux/preadv64.c                 |   2 +
>  sysdeps/unix/sysv/linux/preadv64v2.c               |  55 +++++++++++
>  sysdeps/unix/sysv/linux/pwrite64.c                 |   1 +
>  sysdeps/unix/sysv/linux/pwritev.c                  |   2 +
>  sysdeps/unix/sysv/linux/pwritev2.c                 |  51 ++++++++++
>  sysdeps/unix/sysv/linux/pwritev64.c                |   2 +
>  sysdeps/unix/sysv/linux/pwritev64v2.c              |  55 +++++++++++
>  sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist  |   5 +
>  sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist  |   5 +
>  sysdeps/unix/sysv/linux/sh/libc.abilist            |   5 +
>  sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist |   5 +
>  sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist |   5 +
>  .../sysv/linux/tile/tilegx/tilegx32/libc.abilist   |   5 +
>  .../sysv/linux/tile/tilegx/tilegx64/libc.abilist   |   5 +
>  sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist  |   5 +
>  sysdeps/unix/sysv/linux/x86_64/64/libc.abilist     |   5 +
>  sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist    |   5 +
>  58 files changed, 1058 insertions(+), 5 deletions(-)
>  create mode 100644 misc/preadv2.c
>  create mode 100644 misc/preadv64v2.c
>  create mode 100644 misc/pwritev2.c
>  create mode 100644 misc/pwritev64v2.c
>  create mode 100644 misc/tst-preadvwritev2.c
>  create mode 100644 misc/tst-preadvwritev64v2.c
>  create mode 100644 sysdeps/posix/preadv2.c
>  create mode 100644 sysdeps/posix/preadv64v2.c
>  create mode 100644 sysdeps/posix/pwritev2.c
>  create mode 100644 sysdeps/posix/pwritev64v2.c
>  create mode 100644 sysdeps/unix/sysv/linux/preadv2.c
>  create mode 100644 sysdeps/unix/sysv/linux/preadv64v2.c
>  create mode 100644 sysdeps/unix/sysv/linux/pwritev2.c
>  create mode 100644 sysdeps/unix/sysv/linux/pwritev64v2.c
> 
> diff --git a/NEWS b/NEWS
> index 5558ca3..afad4b1 100644
> --- a/NEWS
> +++ b/NEWS
> @@ -57,6 +57,13 @@ Version 2.26
>    be added on next major revision of POSIX, so current support is enabled
>    with _GNU_SOURCE.
>  
> +* New preadv2 and pwritev2 are added to libc.  They are Linux extensions to
> +  preadv and pwritev with an additional flag argument where it is possible
> +  to set high priority or use O_DSYNC or O_SYNC for an specific IO operation.
> +  For complete support it requires Linux kernel version 4.6, otherwise a
> +  compat implementation will be used (which refuses all flags and routes it
> +  to preadv or pwritev).
> +
>  Security related changes:
>  
>  * The DNS stub resolver limits the advertised UDP buffer size to 1200 bytes,
> diff --git a/include/sys/uio.h b/include/sys/uio.h
> index f44ce18..20860bf 100644
> --- a/include/sys/uio.h
> +++ b/include/sys/uio.h
> @@ -7,5 +7,11 @@ extern ssize_t __readv (int __fd, const struct iovec *__iovec,
>  			int __count);
>  extern ssize_t __writev (int __fd, const struct iovec *__iovec,
>  			 int __count);
> +
> +/* Used for p{read,write}{v64}v2 implementation.  */
> +libc_hidden_proto (preadv)
> +libc_hidden_proto (preadv64)
> +libc_hidden_proto (pwritev)
> +libc_hidden_proto (pwritev64)
>  #endif
>  #endif
> diff --git a/manual/llio.texi b/manual/llio.texi
> index dae3754..404a966 100644
> --- a/manual/llio.texi
> +++ b/manual/llio.texi
> @@ -756,6 +756,115 @@ When the source file is compiled using @code{_FILE_OFFSET_BITS == 64} on a
>  @code{pwritev} and so transparently replaces the 32 bit interface.
>  @end deftypefun
>  
> +@comment sys/uio.h
> +@comment GNU
> +@deftypefun ssize_t preadv2 (int @var{fd}, const struct iovec *@var{iov}, int @var{iovcnt}, off_t @var{offset}, int @var{flags})
> +@safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}}
> +@c This is a syscall for Linux v4.6.  The sysdeps/posix fallback emulation
> +@c is also MT-Safe since it calls preadv.
> +
> +This function is similar to the @code{preadv} function, with the difference
> +it adds an extra @var{flags} parameter of type @code{int}.  The supported
> +@var{flags} are dependent of the underlying system.  For Linux it supports:
> +
> +@vtable @code
> +@item RWF_HIPRI
> +High priority request.  This adds a flag that tells the file system that
> +this is a high priority request for which it is worth to poll the hardware.
> +The flag is purely advisory and can be ignored if not supported.  The
> +@var{fd} must be opened using @code{O_DIRECT}.
> +
> +@item RWF_DSYNC
> +Per-IO synchronization as if the file was opened with @code{O_DSYNC} flag.
> +
> +@item RWF_SYNC
> +Per-IO synchronization as if the file was opened with @code{O_SYNC} flag.
> +@end vtable
> +
> +When the source file is compiled with @code{_FILE_OFFSET_BITS == 64} the
> +@code{preadv2} function is in fact @code{preadv64v2} and the type
> +@code{off_t} has 64 bits, which makes it possible to handle files up to
> +@twoexp{63} bytes in length.
> +
> +The return value is a count of bytes (@emph{not} buffers) read, @math{0}
> +indicating end-of-file, or @math{-1} indicating an error.  The possible
> +errors are the same as in @code{preadv} with the addition of:
> +
> +@table @code
> +
> +@item EOPNOTSUPP
> +
> +@c The default sysdeps/posix code will return it for any flags value
> +@c different than 0.
> +An unsupported @var{flags} was used.
> +
> +@end table
> +
> +@end deftypefun
> +
> +@comment unistd.h
> +@comment GNU
> +@deftypefun ssize_t preadv64v2 (int @var{fd}, const struct iovec *@var{iov}, int @var{iovcnt}, off64_t @var{offset}, int @var{flags})
> +@safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}}
> +@c This is a syscall for Linux v4.6.  The sysdeps/posix fallback emulation
> +@c is also MT-Safe since it calls preadv.
> +
> +This function is similar to the @code{preadv2} function with the difference
> +is that the @var{offset} parameter is of type @code{off64_t} instead of
> +@code{off_t}.  It makes it possible on 32 bit machines to address
> +files larger than @twoexp{31} bytes and up to @twoexp{63} bytes.  The
> +file descriptor @code{filedes} must be opened using @code{open64} since
> +otherwise the large offsets possible with @code{off64_t} will lead to
> +errors with a descriptor in small file mode.
> +
> +When the source file is compiled using @code{_FILE_OFFSET_BITS == 64} on a
> +32 bit machine this function is actually available under the name
> +@code{preadv2} and so transparently replaces the 32 bit interface.
> +@end deftypefun
> +
> +
> +@comment sys/uio.h
> +@comment GNU
> +@deftypefun ssize_t pwritev2 (int @var{fd}, const struct iovec *@var{iov}, int @var{iovcnt}, off_t @var{offset}, int @var{flags})
> +@safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}}
> +@c This is a syscall for Linux v4.6.  The sysdeps/posix fallback emulation
> +@c is also MT-Safe since it calls pwritev.
> +
> +This function is similar to the @code{pwritev} function, with the difference
> +it adds an extra @var{flags} parameter of type @code{int}.  The supported
> +@var{flags} are dependent of the underlying system and for Linux it supports
> +the same ones as for @code{preadv2}.
> +
> +When the source file is compiled with @code{_FILE_OFFSET_BITS == 64} the
> +@code{pwritev2} function is in fact @code{pwritev64v2} and the type
> +@code{off_t} has 64 bits, which makes it possible to handle files up to
> +@twoexp{63} bytes in length.
> +
> +The return value is a count of bytes (@emph{not} buffers) write, @math{0}
> +indicating end-of-file, or @math{-1} indicating an error.  The possible
> +errors are the same as in @code{preadv2}.
> +@end deftypefun
> +
> +@comment unistd.h
> +@comment GNU
> +@deftypefun ssize_t pwritev64v2 (int @var{fd}, const struct iovec *@var{iov}, int @var{iovcnt}, off64_t @var{offset}, int @var{flags})
> +@safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}}
> +@c This is a syscall for Linux v4.6.  The sysdeps/posix fallback emulation
> +@c is also MT-Safe since it calls pwritev.
> +
> +This function is similar to the @code{pwritev2} function with the difference
> +is that the @var{offset} parameter is of type @code{off64_t} instead of
> +@code{off_t}.  It makes it possible on 32 bit machines to address
> +files larger than @twoexp{31} bytes and up to @twoexp{63} bytes.  The
> +file descriptor @code{filedes} must be opened using @code{open64} since
> +otherwise the large offsets possible with @code{off64_t} will lead to
> +errors with a descriptor in small file mode.
> +
> +When the source file is compiled using @code{_FILE_OFFSET_BITS == 64} on a
> +32 bit machine this function is actually available under the name
> +@code{pwritev2} and so transparently replaces the 32 bit interface.
> +@end deftypefun
> +
>  
>  @node File Position Primitive
>  @section Setting the File Position of a Descriptor
> diff --git a/misc/Makefile b/misc/Makefile
> index 622da67..bed46d7 100644
> --- a/misc/Makefile
> +++ b/misc/Makefile
> @@ -39,6 +39,7 @@ headers	:= sys/uio.h bits/uio.h sys/ioctl.h bits/ioctls.h bits/ioctl-types.h \
>  
>  routines := brk sbrk sstk ioctl \
>  	    readv writev preadv preadv64 pwritev pwritev64 \
> +	    preadv2 preadv64v2 pwritev2 pwritev64v2 \
>  	    setreuid setregid \
>  	    seteuid setegid \
>  	    getpagesize \
> @@ -79,7 +80,9 @@ gpl2lgpl := error.c error.h
>  tests := tst-dirname tst-tsearch tst-fdset tst-efgcvt tst-mntent tst-hsearch \
>  	 tst-error1 tst-pselect tst-insremque tst-mntent2 bug-hsearch1 \
>  	 tst-mntent-blank-corrupt tst-mntent-blank-passno bug18240 \
> -	 tst-preadvwritev tst-preadvwritev64 tst-makedev tst-empty \
> +	 tst-preadvwritev tst-preadvwritev64 tst-preadvwritev2 \
> +	 tst-preadvwritev64v2 \
> +	 tst-makedev tst-empty \
>  	 tst-atomic tst-atomic-long
>  tests-static := tst-empty
>  
> diff --git a/misc/Versions b/misc/Versions
> index f2c90ff..bafda78 100644
> --- a/misc/Versions
> +++ b/misc/Versions
> @@ -155,6 +155,9 @@ libc {
>    GLIBC_2.25 {
>      gnu_dev_major; gnu_dev_minor; gnu_dev_makedev;
>    }
> +  GLIBC_2.26 {
> +    preadv2; preadv64v2; pwritev2; pwritev64v2;
> +  }
>    GLIBC_PRIVATE {
>      __madvise;
>      __mktemp;
> diff --git a/misc/preadv2.c b/misc/preadv2.c
> new file mode 100644
> index 0000000..a62dcaa
> --- /dev/null
> +++ b/misc/preadv2.c
> @@ -0,0 +1,30 @@
> +/* Default implementation of preadv2.
> +   Copyright (C) 2017 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <http://www.gnu.org/licenses/>.  */
> +
> +#include <sys/uio.h>
> +
> +/* Same as preadv but with an additional flags argument.  */
> +ssize_t
> +preadv2 (int fd, const struct iovec *vector, int count, off_t offset,
> +	 int flags)
> +{
> +  __set_errno (ENOSYS);
> +  return -1;
> +}
> +
> +stub_warning (preadv2)
> diff --git a/misc/preadv64v2.c b/misc/preadv64v2.c
> new file mode 100644
> index 0000000..a802c2f
> --- /dev/null
> +++ b/misc/preadv64v2.c
> @@ -0,0 +1,30 @@
> +/* Default implementation of preadv2 (LFS version).
> +   Copyright (C) 2017 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <http://www.gnu.org/licenses/>.  */
> +
> +#include <sys/uio.h>
> +
> +/* Same as preadv64 but with an addional flag argument.  */
> +ssize_t
> +preadv64v2 (int fd, const struct iovec *vector, int count, off64_t offset,
> +	    int flags)
> +{
> +  __set_errno (ENOSYS);
> +  return -1;
> +}
> +
> +stub_warning (preadv64v2)
> diff --git a/misc/pwritev2.c b/misc/pwritev2.c
> new file mode 100644
> index 0000000..b9e0727
> --- /dev/null
> +++ b/misc/pwritev2.c
> @@ -0,0 +1,30 @@
> +/* Default implementation of pwritev2.
> +   Copyright (C) 2017 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <http://www.gnu.org/licenses/>.  */
> +
> +#include <sys/uio.h>
> +
> +/* Same as pwritev but with an additional flags argument.  */
> +ssize_t
> +pwritev2 (int fd, const struct iovec *vector, int count, off_t offset,
> +	  int flags)
> +{
> +  __set_errno (ENOSYS);
> +  return -1;
> +}
> +
> +stub_warning (pwritev2)
> diff --git a/misc/pwritev64v2.c b/misc/pwritev64v2.c
> new file mode 100644
> index 0000000..1f874f0
> --- /dev/null
> +++ b/misc/pwritev64v2.c
> @@ -0,0 +1,30 @@
> +/* Default implementation of pwritev2 (LFS version).
> +   Copyright (C) 2017 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <http://www.gnu.org/licenses/>.  */
> +
> +#include <sys/uio.h>
> +
> +/* Same as preadv64 but with an addional flag argument.  */
> +ssize_t
> +pwritev64v2 (int fd, const struct iovec *vector, int count, off64_t offset,
> +	     int flags)
> +{
> +  __set_errno (ENOSYS);
> +  return -1;
> +}
> +
> +stub_warning (pwritev64v2)
> diff --git a/misc/sys/uio.h b/misc/sys/uio.h
> index e80f013..66c22f0 100644
> --- a/misc/sys/uio.h
> +++ b/misc/sys/uio.h
> @@ -76,6 +76,7 @@ extern ssize_t preadv (int __fd, const struct iovec *__iovec, int __count,
>     __THROW.  */
>  extern ssize_t pwritev (int __fd, const struct iovec *__iovec, int __count,
>  			__off_t __offset) __wur;
> +
>  # else
>  #  ifdef __REDIRECT
>  extern ssize_t __REDIRECT (preadv, (int __fd, const struct iovec *__iovec,
> @@ -117,6 +118,46 @@ extern ssize_t pwritev64 (int __fd, const struct iovec *__iovec, int __count,
>  # endif
>  #endif	/* Use misc.  */
>  
> +
> +#ifdef __USE_GNU
> +# ifndef __USE_FILE_OFFSET64
> +/* Same as preadv but with an additional flag argumenti defined at uio.h.  */
> +extern ssize_t preadv2 (int __fp, const struct iovec *__iovec, int __count,
> +			__off_t __offset, int ___flags) __wur;
> +
> +/* Same as preadv but with an additional flag argument defined at uio.h.  */
> +extern ssize_t pwritev2 (int __fd, const struct iovec *__iodev, int __count,
> +			 __off_t __offset, int __flags) __wur;
> +
> +# else
> +#  ifdef __REDIRECT
> +extern ssize_t __REDIRECT (pwritev2, (int __fd, const struct iovec *__iovec,
> +				      int __count, __off64_t __offset,
> +				      int __flags),
> +			   pwritev64v2) __wur;
> +extern ssize_t __REDIRECT (preadv2, (int __fd, const struct iovec *__iovec,
> +				     int __count, __off64_t __offset,
> +				     int __flags),
> +			   preadv64v2) __wur;
> +#  else
> +#   define preadv2 preadv64v2
> +#   define pwritev2 pwritev64v2
> +#  endif
> +# endif
> +
> +# ifdef __USE_LARGEFILE64
> +/* Same as preadv but with an additional flag argumenti defined at uio.h.  */
> +extern ssize_t preadv64v2 (int __fp, const struct iovec *__iovec,
> +			   int __count, __off64_t __offset,
> +			   int ___flags) __wur;
> +
> +/* Same as preadv but with an additional flag argument defined at uio.h.  */
> +extern ssize_t pwritev64v2 (int __fd, const struct iovec *__iodev,
> +			    int __count, __off64_t __offset,
> +			    int __flags) __wur;
> +# endif
> +#endif /* Use GNU.  */
> +
>  __END_DECLS
>  
>  #endif /* sys/uio.h */
> diff --git a/misc/tst-preadvwritev-common.c b/misc/tst-preadvwritev-common.c
> index 5540dfb..676d495 100644
> --- a/misc/tst-preadvwritev-common.c
> +++ b/misc/tst-preadvwritev-common.c
> @@ -18,6 +18,7 @@
>  
>  #include <stdio.h>
>  #include <stdint.h>
> +#include <errno.h>
>  #include <string.h>
>  #include <sys/uio.h>
>  #include <sys/stat.h>
> @@ -39,6 +40,16 @@ do_prepare (int argc, char **argv)
>  }
>  #define PREPARE do_prepare
>  
> +#ifndef PREADV
> +# define PREADV(__fd, __iov, __iovcnt, __offset) \
> +  preadv (__fd, __iov, __iovcnt, __offset)
> +#endif
> +
> +#ifndef PWRITEV
> +# define PWRITEV(__fd, __iov, __iovcnt, __offset) \
> +  pwritev (__fd, __iov, __iovcnt, __offset)
> +#endif
> +
>  static int
>  do_test_with_offset (off_t offset)
>  {
> @@ -58,13 +69,13 @@ do_test_with_offset (off_t offset)
>    iov[1].iov_base = buf2;
>    iov[1].iov_len = sizeof buf2;
>  
> -  ret = pwritev (temp_fd, iov, 2, offset);
> +  ret = PWRITEV (temp_fd, iov, 2, offset);
>    if (ret == -1)
>      FAIL_RET ("first pwritev returned -1");
>    if (ret != (sizeof buf1 + sizeof buf2))
>      FAIL_RET ("first pwritev returned an unexpected value");
>  
> -  ret = pwritev (temp_fd, iov, 2, sizeof buf1 + sizeof buf2 + offset);
> +  ret = PWRITEV (temp_fd, iov, 2, sizeof buf1 + sizeof buf2 + offset);
>    if (ret == -1)
>      FAIL_RET ("second pwritev returned -1");
>    if (ret != (sizeof buf1 + sizeof buf2))
> @@ -82,7 +93,7 @@ do_test_with_offset (off_t offset)
>    iov[1].iov_len = sizeof buf4;
>  
>    /* Now read two buffer with 32 and 64 bytes respectively.  */
> -  ret = preadv (temp_fd, iov, 2, offset);
> +  ret = PREADV (temp_fd, iov, 2, offset);
>    if (ret == -1)
>      FAIL_RET ("first preadv returned -1");
>    if (ret != (sizeof buf3 + sizeof buf4))
> @@ -93,7 +104,7 @@ do_test_with_offset (off_t offset)
>    if (memcmp (buf2, buf4, sizeof buf2) != 0)
>      FAIL_RET ("second buffer from first preadv different than expected");
>  
> -  ret = preadv (temp_fd, iov, 2, sizeof buf3 + sizeof buf4 + offset);
> +  ret = PREADV (temp_fd, iov, 2, sizeof buf3 + sizeof buf4 + offset);
>    if (ret == -1)
>      FAIL_RET ("second preadv returned -1");
>    if (ret != (sizeof buf3 + sizeof buf4))
> diff --git a/misc/tst-preadvwritev2.c b/misc/tst-preadvwritev2.c
> new file mode 100644
> index 0000000..cf36272
> --- /dev/null
> +++ b/misc/tst-preadvwritev2.c
> @@ -0,0 +1,31 @@
> +/* Tests for preadv2 and pwritev2.
> +   Copyright (C) 2016-2017 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <http://www.gnu.org/licenses/>.  */
> +
> +#define PREADV(__fd, __iov, __iovcnt, __offset) \
> +  preadv2 (__fd, __iov, __iovcnt, __offset, 0)
> +
> +#define PWRITEV(__fd, __iov, __iovcnt, __offset) \
> +  pwritev2 (__fd, __iov, __iovcnt, __offset, 0)
> +
> +#include "tst-preadvwritev-common.c"
> +
> +static int
> +do_test (void)
> +{
> +  return do_test_with_offset (0);
> +}
> diff --git a/misc/tst-preadvwritev64v2.c b/misc/tst-preadvwritev64v2.c
> new file mode 100644
> index 0000000..8d0c48e
> --- /dev/null
> +++ b/misc/tst-preadvwritev64v2.c
> @@ -0,0 +1,33 @@
> +/* Tests for preadv2 and pwritev2 (LFS version).
> +   Copyright (C) 2017 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <http://www.gnu.org/licenses/>.  */
> +
> +#define _FILE_OFFSET_BITS 64
> +
> +#define PREADV(__fd, __iov, __iovcnt, __offset) \
> +  preadv2 (__fd, __iov, __iovcnt, __offset, 0)
> +
> +#define PWRITEV(__fd, __iov, __iovcnt, __offset) \
> +  pwritev2 (__fd, __iov, __iovcnt, __offset, 0)
> +
> +#include "tst-preadvwritev-common.c"
> +
> +static int
> +do_test (void)
> +{
> +  return do_test_with_offset (0);
> +}
> diff --git a/nptl/tst-cancel4.c b/nptl/tst-cancel4.c
> index e66961f..7a560a1 100644
> --- a/nptl/tst-cancel4.c
> +++ b/nptl/tst-cancel4.c
> @@ -1079,6 +1079,75 @@ tf_pwritev (void *arg)
>  }
>  
>  static void *
> +tf_pwritev2 (void *arg)
> +{
> +  int fd;
> +
> +  if (arg == NULL)
> +    /* XXX If somebody can provide a portable test case in which pwritev2
> +       blocks we can enable this test to run in both rounds.  */
> +    abort ();
> +
> +  errno = 0;
> +
> +  char fname[] = "/tmp/tst-cancel4-fd-XXXXXX";
> +  tempfd = fd = mkstemp (fname);
> +  if (fd == -1)
> +    FAIL_EXIT1 ("mkstemp: %m");
> +  unlink (fname);
> +
> +  xpthread_barrier_wait (&b2);
> +
> +  xpthread_barrier_wait (&b2);
> +
> +  ssize_t s;
> +  pthread_cleanup_push (cl, NULL);
> +
> +  char buf[WRITE_BUFFER_SIZE];
> +  memset (buf, '\0', sizeof (buf));
> +  struct iovec iov[1] = { [0] = { .iov_base = buf, .iov_len = sizeof (buf) } };
> +  s = pwritev2 (fd, iov, 1, 0, 0);
> +
> +  pthread_cleanup_pop (0);
> +
> +  FAIL_EXIT1 ("pwritev2 returns with %zd", s);
> +}
> +
> +static void *
> +tf_preadv2 (void *arg)
> +{
> +  int fd;
> +
> +  if (arg == NULL)
> +    /* XXX If somebody can provide a portable test case in which preadv2
> +       blocks we can enable this test to run in both rounds.  */
> +    abort ();
> +
> +  errno = 0;
> +
> +  char fname[] = "/tmp/tst-cancel4-fd-XXXXXX";
> +  tempfd = fd = mkstemp (fname);
> +  if (fd == -1)
> +    FAIL_EXIT1 ("mkstemp failed: %m");
> +  unlink (fname);
> +
> +  xpthread_barrier_wait (&b2);
> +
> +  xpthread_barrier_wait (&b2);
> +
> +  ssize_t s;
> +  pthread_cleanup_push (cl, NULL);
> +
> +  char buf[100];
> +  struct iovec iov[1] = { [0] = { .iov_base = buf, .iov_len = sizeof (buf) } };
> +  s = preadv2 (fd, iov, 1, 0, 0);
> +
> +  pthread_cleanup_pop (0);
> +
> +  FAIL_EXIT1 ("preadv2 returns with %zd", s);
> +}
> +
> +static void *
>  tf_fsync (void *arg)
>  {
>    if (arg == NULL)
> @@ -1473,7 +1542,9 @@ struct cancel_tests tests[] =
>    ADD_TEST (recvfrom, 2, 0),
>    ADD_TEST (recvmsg, 2, 0),
>    ADD_TEST (preadv, 2, 1),
> +  ADD_TEST (preadv2, 2, 1),
>    ADD_TEST (pwritev, 2, 1),
> +  ADD_TEST (pwritev2, 2, 1),
>    ADD_TEST (open, 2, 1),
>    ADD_TEST (close, 2, 1),
>    ADD_TEST (pread, 2, 1),
> diff --git a/sysdeps/posix/preadv2.c b/sysdeps/posix/preadv2.c
> new file mode 100644
> index 0000000..2a7cf11
> --- /dev/null
> +++ b/sysdeps/posix/preadv2.c
> @@ -0,0 +1,38 @@
> +/* Generic version of preadv2.
> +   Copyright (C) 2017 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <http://www.gnu.org/licenses/>.  */
> +
> +#include <unistd.h>
> +#include <sys/uio.h>
> +
> +#ifndef __OFF_T_MATCHES_OFF64_T
> +
> +/* Since we define no flags for preadv2 just route to preadv.  */
> +ssize_t
> +preadv2 (int fd, const struct iovec *vector, int count, OFF_T offset,
> +	 int flags)
> +{
> +  if (flags != 0)
> +    {
> +      __set_errno (EOPNOTSUPP);
> +      return -1;
> +    }
> +
> +  return preadv (fd, vector, count, offset);
> +}
> +
> +#endif
> diff --git a/sysdeps/posix/preadv64v2.c b/sysdeps/posix/preadv64v2.c
> new file mode 100644
> index 0000000..e084f3f
> --- /dev/null
> +++ b/sysdeps/posix/preadv64v2.c
> @@ -0,0 +1,37 @@
> +/* Generic version of preadv2.
> +   Copyright (C) 2017 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <http://www.gnu.org/licenses/>.  */
> +
> +#include <unistd.>
> +#include <sys/uio.h>
> +
> +ssize_t
> +preadv64v2 (int fd, const struct iovec *vector, int count, OFF_T offset,
> +	    int flags)
> +{
> +  if (flags != 0)
> +    {
> +      __set_errno (EOPNOTSUPP);
> +      return -1;
> +    }
> +
> +  return preadv64 (fd, vector, count, offset);
> +}
> +
> +#ifdef __OFF_T_MATCHES_OFF64_T
> +strong_alias (preadv64v2, preadv2)
> +#endif
> diff --git a/sysdeps/posix/pwritev2.c b/sysdeps/posix/pwritev2.c
> new file mode 100644
> index 0000000..5b7650c
> --- /dev/null
> +++ b/sysdeps/posix/pwritev2.c
> @@ -0,0 +1,38 @@
> +/* Generic version of pwritev2.
> +   Copyright (C) 2017 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <http://www.gnu.org/licenses/>.  */
> +
> +#include <unistd.h>
> +#include <sys/uio.h>
> +
> +#ifndef __OFF_T_MATCHES_OFF64_T
> +
> +/* Since we define no flags for pwritev2 just route to pwritev.  */
> +ssize_t
> +pwritev2 (int fd, const struct iovec *vector, int count, OFF_T offset,
> +	  int flags)
> +{
> +  if (flags != 0)
> +    {
> +      __set_errno (EOPNOTSUPP);
> +      return -1;
> +    }
> +
> +  return pwritev (fd, vector, count, offset);
> +}
> +
> +#endif
> diff --git a/sysdeps/posix/pwritev64v2.c b/sysdeps/posix/pwritev64v2.c
> new file mode 100644
> index 0000000..d9727b9
> --- /dev/null
> +++ b/sysdeps/posix/pwritev64v2.c
> @@ -0,0 +1,38 @@
> +/* Generic version of pwritev2.
> +   Copyright (C) 2017 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <http://www.gnu.org/licenses/>.  */
> +
> +#include <unistd.h>
> +#include <sys/uio.h>
> +
> +/* Since we define no flags for pwritev2 just route to pwritev.  */ 
> +ssize_t
> +pwritev64v2 (int fd, const struct iovec *vector, int count, OFF_T offset,
> +	     int flags)
> +{
> +  if (flags != 0)
> +    {
> +      __set_errno (EOPNOTSUPP);
> +      return -1;
> +    }
> +
> +  return pwritev64 (fd, vector, count, offset);
> +}
> +
> +#ifdef __OFF_T_MATCHES_OFF64_T
> +strong_alias (pwritev64v2, pwritev2)
> +#endif
> diff --git a/sysdeps/unix/sysv/linux/aarch64/libc.abilist b/sysdeps/unix/sysv/linux/aarch64/libc.abilist
> index 58d768c..296f2a5 100644
> --- a/sysdeps/unix/sysv/linux/aarch64/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/aarch64/libc.abilist
> @@ -2097,3 +2097,8 @@ GLIBC_2.25 getrandom F
>  GLIBC_2.25 strfromd F
>  GLIBC_2.25 strfromf F
>  GLIBC_2.25 strfroml F
> +GLIBC_2.26 GLIBC_2.26 A
> +GLIBC_2.26 preadv2 F
> +GLIBC_2.26 preadv64v2 F
> +GLIBC_2.26 pwritev2 F
> +GLIBC_2.26 pwritev64v2 F
> diff --git a/sysdeps/unix/sysv/linux/alpha/libc.abilist b/sysdeps/unix/sysv/linux/alpha/libc.abilist
> index 906050d..8006e72 100644
> --- a/sysdeps/unix/sysv/linux/alpha/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/alpha/libc.abilist
> @@ -2008,6 +2008,11 @@ GLIBC_2.25 getrandom F
>  GLIBC_2.25 strfromd F
>  GLIBC_2.25 strfromf F
>  GLIBC_2.25 strfroml F
> +GLIBC_2.26 GLIBC_2.26 A
> +GLIBC_2.26 preadv2 F
> +GLIBC_2.26 preadv64v2 F
> +GLIBC_2.26 pwritev2 F
> +GLIBC_2.26 pwritev64v2 F
>  GLIBC_2.3 GLIBC_2.3 A
>  GLIBC_2.3 __ctype_b_loc F
>  GLIBC_2.3 __ctype_tolower_loc F
> diff --git a/sysdeps/unix/sysv/linux/arm/libc.abilist b/sysdeps/unix/sysv/linux/arm/libc.abilist
> index 66112dd..29f9688 100644
> --- a/sysdeps/unix/sysv/linux/arm/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/arm/libc.abilist
> @@ -98,6 +98,11 @@ GLIBC_2.25 getrandom F
>  GLIBC_2.25 strfromd F
>  GLIBC_2.25 strfromf F
>  GLIBC_2.25 strfroml F
> +GLIBC_2.26 GLIBC_2.26 A
> +GLIBC_2.26 preadv2 F
> +GLIBC_2.26 preadv64v2 F
> +GLIBC_2.26 pwritev2 F
> +GLIBC_2.26 pwritev64v2 F
>  GLIBC_2.4 GLIBC_2.4 A
>  GLIBC_2.4 _Exit F
>  GLIBC_2.4 _IO_2_1_stderr_ D 0xa0
> diff --git a/sysdeps/unix/sysv/linux/bits/uio.h b/sysdeps/unix/sysv/linux/bits/uio.h
> index 1583f04..d5701f8 100644
> --- a/sysdeps/unix/sysv/linux/bits/uio.h
> +++ b/sysdeps/unix/sysv/linux/bits/uio.h
> @@ -69,4 +69,10 @@ extern ssize_t process_vm_writev (pid_t __pid, const struct iovec *__lvec,
>  __END_DECLS
>  
>  # endif
> +
> +/* Flags for preadv2/pwritev2: */
> +#define RWF_HIPRI	0x00000001 /* High priority request.  */
> +#define RWF_DSYNC	0x00000002 /* per-IO O_DSYNC.  */
> +#define RWF_SYNC	0x00000004 /* per-IO O_SYNC.  */
> +
>  #endif
> diff --git a/sysdeps/unix/sysv/linux/hppa/libc.abilist b/sysdeps/unix/sysv/linux/hppa/libc.abilist
> index 3ddadd2..e9cfbaf 100644
> --- a/sysdeps/unix/sysv/linux/hppa/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/hppa/libc.abilist
> @@ -1862,6 +1862,11 @@ GLIBC_2.25 getrandom F
>  GLIBC_2.25 strfromd F
>  GLIBC_2.25 strfromf F
>  GLIBC_2.25 strfroml F
> +GLIBC_2.26 GLIBC_2.26 A
> +GLIBC_2.26 preadv2 F
> +GLIBC_2.26 preadv64v2 F
> +GLIBC_2.26 pwritev2 F
> +GLIBC_2.26 pwritev64v2 F
>  GLIBC_2.3 GLIBC_2.3 A
>  GLIBC_2.3 __ctype_b_loc F
>  GLIBC_2.3 __ctype_tolower_loc F
> diff --git a/sysdeps/unix/sysv/linux/i386/libc.abilist b/sysdeps/unix/sysv/linux/i386/libc.abilist
> index 977ab90..c6ad3c3 100644
> --- a/sysdeps/unix/sysv/linux/i386/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/i386/libc.abilist
> @@ -2020,6 +2020,11 @@ GLIBC_2.25 getrandom F
>  GLIBC_2.25 strfromd F
>  GLIBC_2.25 strfromf F
>  GLIBC_2.25 strfroml F
> +GLIBC_2.26 GLIBC_2.26 A
> +GLIBC_2.26 preadv2 F
> +GLIBC_2.26 preadv64v2 F
> +GLIBC_2.26 pwritev2 F
> +GLIBC_2.26 pwritev64v2 F
>  GLIBC_2.3 GLIBC_2.3 A
>  GLIBC_2.3 __ctype_b_loc F
>  GLIBC_2.3 __ctype_tolower_loc F
> diff --git a/sysdeps/unix/sysv/linux/ia64/libc.abilist b/sysdeps/unix/sysv/linux/ia64/libc.abilist
> index c7edb9a..d0055a2 100644
> --- a/sysdeps/unix/sysv/linux/ia64/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/ia64/libc.abilist
> @@ -1884,6 +1884,11 @@ GLIBC_2.25 getrandom F
>  GLIBC_2.25 strfromd F
>  GLIBC_2.25 strfromf F
>  GLIBC_2.25 strfroml F
> +GLIBC_2.26 GLIBC_2.26 A
> +GLIBC_2.26 preadv2 F
> +GLIBC_2.26 preadv64v2 F
> +GLIBC_2.26 pwritev2 F
> +GLIBC_2.26 pwritev64v2 F
>  GLIBC_2.3 GLIBC_2.3 A
>  GLIBC_2.3 __ctype_b_loc F
>  GLIBC_2.3 __ctype_tolower_loc F
> diff --git a/sysdeps/unix/sysv/linux/kernel-features.h b/sysdeps/unix/sysv/linux/kernel-features.h
> index b981466..8ee1af7 100644
> --- a/sysdeps/unix/sysv/linux/kernel-features.h
> +++ b/sysdeps/unix/sysv/linux/kernel-features.h
> @@ -137,3 +137,8 @@
>  /* Support for SysV IPC through wired syscalls.  All supported architectures
>     either support ipc syscall and/or all the ipc correspondent syscalls.  */
>  #define __ASSUME_DIRECT_SYSVIPC_SYSCALLS	1
> +
> +/* Support for p{read,write}v2 was added in 4.6.  However Linux default
> +   implementation does not assume the __ASSUME_* and instead use a fallback
> +   implementation based on p{read,write}v and returning an error for
> +   non supported flags.  */
> diff --git a/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist b/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
> index 450be4e..3777676 100644
> --- a/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
> @@ -99,6 +99,11 @@ GLIBC_2.25 getrandom F
>  GLIBC_2.25 strfromd F
>  GLIBC_2.25 strfromf F
>  GLIBC_2.25 strfroml F
> +GLIBC_2.26 GLIBC_2.26 A
> +GLIBC_2.26 preadv2 F
> +GLIBC_2.26 preadv64v2 F
> +GLIBC_2.26 pwritev2 F
> +GLIBC_2.26 pwritev64v2 F
>  GLIBC_2.4 GLIBC_2.4 A
>  GLIBC_2.4 _Exit F
>  GLIBC_2.4 _IO_2_1_stderr_ D 0x98
> diff --git a/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist b/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
> index 9e016bd..8b1f80c 100644
> --- a/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
> @@ -1976,6 +1976,11 @@ GLIBC_2.25 getrandom F
>  GLIBC_2.25 strfromd F
>  GLIBC_2.25 strfromf F
>  GLIBC_2.25 strfroml F
> +GLIBC_2.26 GLIBC_2.26 A
> +GLIBC_2.26 preadv2 F
> +GLIBC_2.26 preadv64v2 F
> +GLIBC_2.26 pwritev2 F
> +GLIBC_2.26 pwritev64v2 F
>  GLIBC_2.3 GLIBC_2.3 A
>  GLIBC_2.3 __ctype_b_loc F
>  GLIBC_2.3 __ctype_tolower_loc F
> diff --git a/sysdeps/unix/sysv/linux/microblaze/libc.abilist b/sysdeps/unix/sysv/linux/microblaze/libc.abilist
> index 1a455be..d4db9a8 100644
> --- a/sysdeps/unix/sysv/linux/microblaze/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/microblaze/libc.abilist
> @@ -2097,3 +2097,8 @@ GLIBC_2.25 getrandom F
>  GLIBC_2.25 strfromd F
>  GLIBC_2.25 strfromf F
>  GLIBC_2.25 strfroml F
> +GLIBC_2.26 GLIBC_2.26 A
> +GLIBC_2.26 preadv2 F
> +GLIBC_2.26 preadv64v2 F
> +GLIBC_2.26 pwritev2 F
> +GLIBC_2.26 pwritev64v2 F
> diff --git a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
> index 8eb5e66..f430bdb 100644
> --- a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
> @@ -1951,6 +1951,11 @@ GLIBC_2.25 getrandom F
>  GLIBC_2.25 strfromd F
>  GLIBC_2.25 strfromf F
>  GLIBC_2.25 strfroml F
> +GLIBC_2.26 GLIBC_2.26 A
> +GLIBC_2.26 preadv2 F
> +GLIBC_2.26 preadv64v2 F
> +GLIBC_2.26 pwritev2 F
> +GLIBC_2.26 pwritev64v2 F
>  GLIBC_2.3 GLIBC_2.3 A
>  GLIBC_2.3 __ctype_b_loc F
>  GLIBC_2.3 __ctype_tolower_loc F
> diff --git a/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
> index 416d9ac..a4dca19 100644
> --- a/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
> @@ -1949,6 +1949,11 @@ GLIBC_2.25 getrandom F
>  GLIBC_2.25 strfromd F
>  GLIBC_2.25 strfromf F
>  GLIBC_2.25 strfroml F
> +GLIBC_2.26 GLIBC_2.26 A
> +GLIBC_2.26 preadv2 F
> +GLIBC_2.26 preadv64v2 F
> +GLIBC_2.26 pwritev2 F
> +GLIBC_2.26 pwritev64v2 F
>  GLIBC_2.3 GLIBC_2.3 A
>  GLIBC_2.3 __ctype_b_loc F
>  GLIBC_2.3 __ctype_tolower_loc F
> diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
> index f4949e5..0814fa8 100644
> --- a/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
> @@ -1947,6 +1947,11 @@ GLIBC_2.25 getrandom F
>  GLIBC_2.25 strfromd F
>  GLIBC_2.25 strfromf F
>  GLIBC_2.25 strfroml F
> +GLIBC_2.26 GLIBC_2.26 A
> +GLIBC_2.26 preadv2 F
> +GLIBC_2.26 preadv64v2 F
> +GLIBC_2.26 pwritev2 F
> +GLIBC_2.26 pwritev64v2 F
>  GLIBC_2.3 GLIBC_2.3 A
>  GLIBC_2.3 __ctype_b_loc F
>  GLIBC_2.3 __ctype_tolower_loc F
> diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
> index c7375ae..a0bdeff 100644
> --- a/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
> @@ -1942,6 +1942,11 @@ GLIBC_2.25 getrandom F
>  GLIBC_2.25 strfromd F
>  GLIBC_2.25 strfromf F
>  GLIBC_2.25 strfroml F
> +GLIBC_2.26 GLIBC_2.26 A
> +GLIBC_2.26 preadv2 F
> +GLIBC_2.26 preadv64v2 F
> +GLIBC_2.26 pwritev2 F
> +GLIBC_2.26 pwritev64v2 F
>  GLIBC_2.3 GLIBC_2.3 A
>  GLIBC_2.3 __ctype_b_loc F
>  GLIBC_2.3 __ctype_tolower_loc F
> diff --git a/sysdeps/unix/sysv/linux/nios2/libc.abilist b/sysdeps/unix/sysv/linux/nios2/libc.abilist
> index 724a0e3..b201290 100644
> --- a/sysdeps/unix/sysv/linux/nios2/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/nios2/libc.abilist
> @@ -2138,3 +2138,8 @@ GLIBC_2.25 getrandom F
>  GLIBC_2.25 strfromd F
>  GLIBC_2.25 strfromf F
>  GLIBC_2.25 strfroml F
> +GLIBC_2.26 GLIBC_2.26 A
> +GLIBC_2.26 preadv2 F
> +GLIBC_2.26 preadv64v2 F
> +GLIBC_2.26 pwritev2 F
> +GLIBC_2.26 pwritev64v2 F
> diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
> index 2dc32b6..6e7ff24 100644
> --- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
> @@ -1980,6 +1980,11 @@ GLIBC_2.25 getrandom F
>  GLIBC_2.25 strfromd F
>  GLIBC_2.25 strfromf F
>  GLIBC_2.25 strfroml F
> +GLIBC_2.26 GLIBC_2.26 A
> +GLIBC_2.26 preadv2 F
> +GLIBC_2.26 preadv64v2 F
> +GLIBC_2.26 pwritev2 F
> +GLIBC_2.26 pwritev64v2 F
>  GLIBC_2.3 GLIBC_2.3 A
>  GLIBC_2.3 __ctype_b_loc F
>  GLIBC_2.3 __ctype_tolower_loc F
> diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
> index 5658109..19c7c7d 100644
> --- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
> @@ -1985,6 +1985,11 @@ GLIBC_2.25 getrandom F
>  GLIBC_2.25 strfromd F
>  GLIBC_2.25 strfromf F
>  GLIBC_2.25 strfroml F
> +GLIBC_2.26 GLIBC_2.26 A
> +GLIBC_2.26 preadv2 F
> +GLIBC_2.26 preadv64v2 F
> +GLIBC_2.26 pwritev2 F
> +GLIBC_2.26 pwritev64v2 F
>  GLIBC_2.3 GLIBC_2.3 A
>  GLIBC_2.3 __ctype_b_loc F
>  GLIBC_2.3 __ctype_tolower_loc F
> diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist
> index c761221..e94ce38 100644
> --- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist
> +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist
> @@ -2185,3 +2185,8 @@ GLIBC_2.25 getrandom F
>  GLIBC_2.25 strfromd F
>  GLIBC_2.25 strfromf F
>  GLIBC_2.25 strfroml F
> +GLIBC_2.26 GLIBC_2.26 A
> +GLIBC_2.26 preadv2 F
> +GLIBC_2.26 preadv64v2 F
> +GLIBC_2.26 pwritev2 F
> +GLIBC_2.26 pwritev64v2 F
> diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist
> index 265c769..f3daa33 100644
> --- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist
> @@ -99,6 +99,11 @@ GLIBC_2.25 getrandom F
>  GLIBC_2.25 strfromd F
>  GLIBC_2.25 strfromf F
>  GLIBC_2.25 strfroml F
> +GLIBC_2.26 GLIBC_2.26 A
> +GLIBC_2.26 preadv2 F
> +GLIBC_2.26 preadv64v2 F
> +GLIBC_2.26 pwritev2 F
> +GLIBC_2.26 pwritev64v2 F
>  GLIBC_2.3 GLIBC_2.3 A
>  GLIBC_2.3 _Exit F
>  GLIBC_2.3 _IO_2_1_stderr_ D 0xe0
> diff --git a/sysdeps/unix/sysv/linux/preadv.c b/sysdeps/unix/sysv/linux/preadv.c
> index 7d971cc..ecabc8c 100644
> --- a/sysdeps/unix/sysv/linux/preadv.c
> +++ b/sysdeps/unix/sysv/linux/preadv.c
> @@ -50,4 +50,6 @@ preadv (int fd, const struct iovec *vector, int count, off_t offset)
>  #  define OFF_T off_t
>  #  include <sysdeps/posix/preadv_common.c>
>  # endif /* __ASSUME_PREADV  */
> +
> +libc_hidden_def (preadv)
>  #endif
> diff --git a/sysdeps/unix/sysv/linux/preadv2.c b/sysdeps/unix/sysv/linux/preadv2.c
> new file mode 100644
> index 0000000..11fe85e
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/preadv2.c
> @@ -0,0 +1,55 @@
> +/* Linux implementation of preadv2.
> +   Copyright (C) 2017 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <http://www.gnu.org/licenses/>.  */
> +
> +#include <sys/uio.h>
> +#include <sysdep-cancel.h>
> +
> +#ifndef __OFF_T_MATCHES_OFF64_T
> +
> +# if !defined (__NR_preadv2) && defined (__NR_pread64v2)
> +#  define __NR_preadv2 __NR_pread64v2
> +# endif
> +
> +ssize_t
> +preadv2 (int fd, const struct iovec *vector, int count, off_t offset,
> +	 int flags)
> +{
> +# ifdef __NR_preadv2
> +  ssize_t result = SYSCALL_CANCEL (preadv2, fd, vector, count,
> +				   LO_HI_LONG (offset), flags);
> +  if (result >= 0 || errno != ENOSYS)
> +    return result;
> +# endif
> +  /* Trying to emulate the preadv2 syscall flags is troublesome:
> +
> +     * We can not temporary change the file state of the O_DSYNC and O_SYNC
> +       flags to emulate RWF_{D}SYNC (attempts to change the state of using
> +       fcntl are silently ignored).
> +
> +     * IOCB_HIPRI requires the file opened in O_DIRECT and uses an internal
> +       semantic not provided by any other flag (O_NONBLOCK for instance).  */
> +
> +  if (flags != 0)
> +    {
> +      __set_errno (EOPNOTSUPP);
> +      return -1;
> +    }
> +  return preadv (fd, vector, count, offset);
> +}
> +
> +#endif
> diff --git a/sysdeps/unix/sysv/linux/preadv64.c b/sysdeps/unix/sysv/linux/preadv64.c
> index 66daa74..c96b214 100644
> --- a/sysdeps/unix/sysv/linux/preadv64.c
> +++ b/sysdeps/unix/sysv/linux/preadv64.c
> @@ -48,7 +48,9 @@ preadv64 (int fd, const struct iovec *vector, int count, off64_t offset)
>  # define OFF_T off64_t
>  # include <sysdeps/posix/preadv_common.c>
>  #endif
> +libc_hidden_def (preadv64)
>  
>  #ifdef __OFF_T_MATCHES_OFF64_T
>  strong_alias (preadv64, preadv)
> +libc_hidden_def (preadv)
>  #endif
> diff --git a/sysdeps/unix/sysv/linux/preadv64v2.c b/sysdeps/unix/sysv/linux/preadv64v2.c
> new file mode 100644
> index 0000000..9d7f8c9
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/preadv64v2.c
> @@ -0,0 +1,55 @@
> +/* Linux implementation of preadv2 (LFS version).
> +   Copyright (C) 2017 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <http://www.gnu.org/licenses/>.  */
> +
> +#include <sys/uio.h>
> +#include <sysdep-cancel.h>
> +
> +#if !defined(__NR_preadv64v2) && defined(__NR_preadv2)
> +# define __NR_preadv64v2 __NR_preadv2
> +#endif
> +
> +ssize_t
> +preadv64v2 (int fd, const struct iovec *vector, int count, off64_t offset,
> +	    int flags)
> +{
> +#ifdef __NR_preadv64v2
> +  ssize_t result = SYSCALL_CANCEL (preadv64v2, fd, vector, count,
> +				   LO_HI_LONG (offset), flags);
> +  if (result >= 0 || errno != ENOSYS)
> +    return result;
> +#endif
> +  /* Trying to emulate the preadv2 syscall flags is troublesome:
> +
> +     * We can not temporary change the file state of the O_DSYNC and O_SYNC
> +       flags to emulate RWF_{D}SYNC (attempts to change the state of using
> +       fcntl are silently ignored).
> +
> +     * IOCB_HIPRI requires the file opened in O_DIRECT and uses an internal
> +       semantic not provided by any other flag (O_NONBLOCK for instance).  */
> +
> +  if (flags != 0)
> +    {
> +      __set_errno (EOPNOTSUPP);
> +      return -1;
> +    }
> +  return preadv64 (fd, vector, count, offset);
> +}
> +
> +#ifdef __OFF_T_MATCHES_OFF64_T
> +strong_alias (preadv64v2, preadv2)
> +#endif
> diff --git a/sysdeps/unix/sysv/linux/pwrite64.c b/sysdeps/unix/sysv/linux/pwrite64.c
> index 57e5d20..71959c0 100644
> --- a/sysdeps/unix/sysv/linux/pwrite64.c
> +++ b/sysdeps/unix/sysv/linux/pwrite64.c
> @@ -28,6 +28,7 @@ __libc_pwrite64 (int fd, const void *buf, size_t count, off64_t offset)
>  {
>    return SYSCALL_CANCEL (pwrite64, fd, buf, count, SYSCALL_LL64_PRW (offset));
>  }
> +
>  weak_alias (__libc_pwrite64, __pwrite64)
>  libc_hidden_weak (__pwrite64)
>  weak_alias (__libc_pwrite64, pwrite64)
> diff --git a/sysdeps/unix/sysv/linux/pwritev.c b/sysdeps/unix/sysv/linux/pwritev.c
> index ce02996..7545cb3 100644
> --- a/sysdeps/unix/sysv/linux/pwritev.c
> +++ b/sysdeps/unix/sysv/linux/pwritev.c
> @@ -50,4 +50,6 @@ pwritev (int fd, const struct iovec *vector, int count, off_t offset)
>  #  define OFF_T off_t
>  #  include <sysdeps/posix/pwritev_common.c>
>  # endif /* __ASSUME_PREADV  */
> +
> +libc_hidden_def (pwritev)
>  #endif
> diff --git a/sysdeps/unix/sysv/linux/pwritev2.c b/sysdeps/unix/sysv/linux/pwritev2.c
> new file mode 100644
> index 0000000..72f0471
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/pwritev2.c
> @@ -0,0 +1,51 @@
> +/* Linux implementation of pwritev2.
> +   Copyright (C) 2017 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <http://www.gnu.org/licenses/>.  */
> +
> +#include <sys/uio.h>
> +#include <sysdep-cancel.h>
> +
> +#ifndef __OFF_T_MATCHES_OFF64_T
> +
> +ssize_t
> +pwritev2 (int fd, const struct iovec *vector, int count, off_t offset,
> +	  int flags)
> +{
> +# ifdef __NR_pwritev2
> +  ssize_t result = SYSCALL_CANCEL (pwritev2, fd, vector, count,
> +				   LO_HI_LONG (offset), flags);
> +  if (result >= 0 || errno != ENOSYS)
> +    return result;
> +# endif
> +  /* Trying to emulate the pwritev2 syscall flags is troublesome:
> +
> +     * We can not temporary change the file state of the O_DSYNC and O_SYNC
> +       flags to emulate RWF_{D}SYNC (attempts to change the state of using
> +       fcntl are silently ignored).
> +
> +     * IOCB_HIPRI requires the file opened in O_DIRECT and uses an internal
> +       semantic not provided by any other flag (O_NONBLOCK for instance).  */
> +
> +  if (flags != 0)
> +    {
> +      __set_errno (EOPNOTSUPP);
> +      return -1;
> +    }
> +  return pwritev (fd, vector, count, offset);
> +}
> +
> +#endif
> diff --git a/sysdeps/unix/sysv/linux/pwritev64.c b/sysdeps/unix/sysv/linux/pwritev64.c
> index 45fb90b..9dc4e55 100644
> --- a/sysdeps/unix/sysv/linux/pwritev64.c
> +++ b/sysdeps/unix/sysv/linux/pwritev64.c
> @@ -48,7 +48,9 @@ pwritev64 (int fd, const struct iovec *vector, int count, off64_t offset)
>  # define OFF_T off64_t
>  # include <sysdeps/posix/pwritev_common.c>
>  #endif
> +libc_hidden_def (pwritev64)
>  
>  #ifdef __OFF_T_MATCHES_OFF64_T
>  strong_alias (pwritev64, pwritev)
> +libc_hidden_def (pwritev)
>  #endif
> diff --git a/sysdeps/unix/sysv/linux/pwritev64v2.c b/sysdeps/unix/sysv/linux/pwritev64v2.c
> new file mode 100644
> index 0000000..def9a0b
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/pwritev64v2.c
> @@ -0,0 +1,55 @@
> +/* Linux implementation of pwritev2 (LFS version).
> +   Copyright (C) 2017 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <http://www.gnu.org/licenses/>.  */
> +
> +#include <sys/uio.h>
> +#include <sysdep-cancel.h>
> +
> +#if !defined(__NR_pwritev64v2) && defined(__NR_pwritev2)
> +# define __NR_pwritev64v2 __NR_pwritev2
> +#endif
> +
> +ssize_t
> +pwritev64v2 (int fd, const struct iovec *vector, int count, off64_t offset,
> +	     int flags)
> +{
> +#ifdef __NR_pwritev64v2
> +  ssize_t result = SYSCALL_CANCEL (pwritev64v2, fd, vector, count,
> +				   LO_HI_LONG (offset), flags);
> +  if (result >= 0 || errno != ENOSYS)
> +    return result;
> +#endif
> +  /* Trying to emulate the pwritev2 syscall flags is troublesome:
> +
> +     * We can not temporary change the file state of the O_DSYNC and O_SYNC
> +       flags to emulate RWF_{D}SYNC (attempts to change the state of using
> +       fcntl are silently ignored).
> +
> +     * IOCB_HIPRI requires the file opened in O_DIRECT and uses an internal
> +       semantic not provided by any other flag (O_NONBLOCK for instance).  */
> +
> +  if (flags != 0)
> +    {
> +      __set_errno (EOPNOTSUPP);
> +      return -1;
> +    }
> +  return pwritev64 (fd, vector, count, offset);
> +}
> +
> +#ifdef __OFF_T_MATCHES_OFF64_T
> +strong_alias (pwritev64v2, pwritev2)
> +#endif
> diff --git a/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist b/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
> index ed1b6bf..eb9e72f 100644
> --- a/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
> @@ -1980,6 +1980,11 @@ GLIBC_2.25 getrandom F
>  GLIBC_2.25 strfromd F
>  GLIBC_2.25 strfromf F
>  GLIBC_2.25 strfroml F
> +GLIBC_2.26 GLIBC_2.26 A
> +GLIBC_2.26 preadv2 F
> +GLIBC_2.26 preadv64v2 F
> +GLIBC_2.26 pwritev2 F
> +GLIBC_2.26 pwritev64v2 F
>  GLIBC_2.3 GLIBC_2.3 A
>  GLIBC_2.3 __ctype_b_loc F
>  GLIBC_2.3 __ctype_tolower_loc F
> diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist b/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
> index 2e75d29..1402959 100644
> --- a/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
> @@ -1881,6 +1881,11 @@ GLIBC_2.25 getrandom F
>  GLIBC_2.25 strfromd F
>  GLIBC_2.25 strfromf F
>  GLIBC_2.25 strfroml F
> +GLIBC_2.26 GLIBC_2.26 A
> +GLIBC_2.26 preadv2 F
> +GLIBC_2.26 preadv64v2 F
> +GLIBC_2.26 pwritev2 F
> +GLIBC_2.26 pwritev64v2 F
>  GLIBC_2.3 GLIBC_2.3 A
>  GLIBC_2.3 __ctype_b_loc F
>  GLIBC_2.3 __ctype_tolower_loc F
> diff --git a/sysdeps/unix/sysv/linux/sh/libc.abilist b/sysdeps/unix/sysv/linux/sh/libc.abilist
> index bd74c0c..e9eefcb 100644
> --- a/sysdeps/unix/sysv/linux/sh/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/sh/libc.abilist
> @@ -1866,6 +1866,11 @@ GLIBC_2.25 getrandom F
>  GLIBC_2.25 strfromd F
>  GLIBC_2.25 strfromf F
>  GLIBC_2.25 strfroml F
> +GLIBC_2.26 GLIBC_2.26 A
> +GLIBC_2.26 preadv2 F
> +GLIBC_2.26 preadv64v2 F
> +GLIBC_2.26 pwritev2 F
> +GLIBC_2.26 pwritev64v2 F
>  GLIBC_2.3 GLIBC_2.3 A
>  GLIBC_2.3 __ctype_b_loc F
>  GLIBC_2.3 __ctype_tolower_loc F
> diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist b/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
> index 5584838..967699e 100644
> --- a/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
> @@ -1972,6 +1972,11 @@ GLIBC_2.25 getrandom F
>  GLIBC_2.25 strfromd F
>  GLIBC_2.25 strfromf F
>  GLIBC_2.25 strfroml F
> +GLIBC_2.26 GLIBC_2.26 A
> +GLIBC_2.26 preadv2 F
> +GLIBC_2.26 preadv64v2 F
> +GLIBC_2.26 pwritev2 F
> +GLIBC_2.26 pwritev64v2 F
>  GLIBC_2.3 GLIBC_2.3 A
>  GLIBC_2.3 __ctype_b_loc F
>  GLIBC_2.3 __ctype_tolower_loc F
> diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist b/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
> index efedbe2..9dd938a 100644
> --- a/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
> @@ -1910,6 +1910,11 @@ GLIBC_2.25 getrandom F
>  GLIBC_2.25 strfromd F
>  GLIBC_2.25 strfromf F
>  GLIBC_2.25 strfroml F
> +GLIBC_2.26 GLIBC_2.26 A
> +GLIBC_2.26 preadv2 F
> +GLIBC_2.26 preadv64v2 F
> +GLIBC_2.26 pwritev2 F
> +GLIBC_2.26 pwritev64v2 F
>  GLIBC_2.3 GLIBC_2.3 A
>  GLIBC_2.3 __ctype_b_loc F
>  GLIBC_2.3 __ctype_tolower_loc F
> diff --git a/sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist b/sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist
> index ffd988a..68c9887 100644
> --- a/sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist
> @@ -2104,3 +2104,8 @@ GLIBC_2.25 getrandom F
>  GLIBC_2.25 strfromd F
>  GLIBC_2.25 strfromf F
>  GLIBC_2.25 strfroml F
> +GLIBC_2.26 GLIBC_2.26 A
> +GLIBC_2.26 preadv2 F
> +GLIBC_2.26 preadv64v2 F
> +GLIBC_2.26 pwritev2 F
> +GLIBC_2.26 pwritev64v2 F
> diff --git a/sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist b/sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist
> index f0c13ce..97aa0f7 100644
> --- a/sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist
> @@ -2104,3 +2104,8 @@ GLIBC_2.25 getrandom F
>  GLIBC_2.25 strfromd F
>  GLIBC_2.25 strfromf F
>  GLIBC_2.25 strfroml F
> +GLIBC_2.26 GLIBC_2.26 A
> +GLIBC_2.26 preadv2 F
> +GLIBC_2.26 preadv64v2 F
> +GLIBC_2.26 pwritev2 F
> +GLIBC_2.26 pwritev64v2 F
> diff --git a/sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist b/sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist
> index ffd988a..68c9887 100644
> --- a/sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist
> @@ -2104,3 +2104,8 @@ GLIBC_2.25 getrandom F
>  GLIBC_2.25 strfromd F
>  GLIBC_2.25 strfromf F
>  GLIBC_2.25 strfroml F
> +GLIBC_2.26 GLIBC_2.26 A
> +GLIBC_2.26 preadv2 F
> +GLIBC_2.26 preadv64v2 F
> +GLIBC_2.26 pwritev2 F
> +GLIBC_2.26 pwritev64v2 F
> diff --git a/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist b/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
> index f57004c..2032659 100644
> --- a/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
> @@ -1861,6 +1861,11 @@ GLIBC_2.25 getrandom F
>  GLIBC_2.25 strfromd F
>  GLIBC_2.25 strfromf F
>  GLIBC_2.25 strfroml F
> +GLIBC_2.26 GLIBC_2.26 A
> +GLIBC_2.26 preadv2 F
> +GLIBC_2.26 preadv64v2 F
> +GLIBC_2.26 pwritev2 F
> +GLIBC_2.26 pwritev64v2 F
>  GLIBC_2.3 GLIBC_2.3 A
>  GLIBC_2.3 __ctype_b_loc F
>  GLIBC_2.3 __ctype_tolower_loc F
> diff --git a/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist b/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
> index 05629e1..11a278c 100644
> --- a/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
> @@ -2104,3 +2104,8 @@ GLIBC_2.25 getrandom F
>  GLIBC_2.25 strfromd F
>  GLIBC_2.25 strfromf F
>  GLIBC_2.25 strfroml F
> +GLIBC_2.26 GLIBC_2.26 A
> +GLIBC_2.26 preadv2 F
> +GLIBC_2.26 preadv64v2 F
> +GLIBC_2.26 pwritev2 F
> +GLIBC_2.26 pwritev64v2 F
>
Adhemerval Zanella May 30, 2017, 2:18 p.m. UTC | #2
Ping x2.  Any impeding issue about this patch? Otherwise I would like to push it.

On 11/05/2017 16:01, Adhemerval Zanella wrote:
> Ping.
> 
> On 04/05/2017 09:43, Adhemerval Zanella wrote:
>> Change from previous version:
>>
>>    * Add unsupported flag check for Linux implementation.
>>
>>    * Unsupported/invalid flags now return EOPNOTSUPP instead of
>>      EINVAL.
>>
>>    * Add comment about preadv2 and pwritev2 support on kernel-features.h.
>>
>>    * Add NEWS entry.
>>
>>    * Fix typo in documentation.
>>         
>> --
>>
>> This patch adds support of preadv2 and pwritev2 which are similar to
>> preadv/pwritev but adds an extra flag argument.  As for preadv/pwritev
>> both interfaces are added a non-standard standard GNU API.
>>
>> On default 'posix' implementation trying to emulate the Linux supported
>> flags is troublesome:
>>
>>    * We can not temporary change the file state of the O_DSYNC and O_SYNC
>>      flags to emulate RWF_{D}SYNC (attempts to change the state of using
>>      fcntl are silently ignored).
>>
>>    * IOCB_HIPRI requires the file opened in O_DIRECT and uses an internal
>>      semantic not provided by any other flag (O_NONBLOCK for instance).
>>
>> So default sysdeps/posix implementations fails with EINVAL for any non
>> supported flag (which are none currently) calls generic preadv/pwritev.
>> Basically, it supports only preadv2 called as preadv (with flags sets
>> to 0).
>>
>> The Linux one uses the preadv2/pwritev2 syscall if defined, otherwise it
>> call preadv/writev.  Instead of using the previous __ASSUME_* to
>> unconditionally issue the syscall (and avoid building the fallback routine),
>> it call pread/write if the preadv2/pwritev2 syscalls fails.  The idea
>> is just avoid adding another __ASSUME_* and checking each architecture
>> on every kernel bump and simplify code conditionals.
>>
>> Checked on x86_64-linux-gnu and on i686-linux-gnu and a check with
>> run-built-tests=no on aarch64-linux-gnu, alpha-linux-gnu, arm-linux-gnueabihf,
>> ia64-linux-gnu, m68k-linux-gnu, microblaze-linux-gnu, mips{64,64n32}-linux-gnu,
>> nios2-linux-gnu, powerpc{64,64le}-linux-gnu, s390{x}-linux-gnu,
>> sparc{64,v9}-linux-gnu, tile{gx,pro}-linux-gnu, and sh4-linux-gnu (all using
>> gcc 6.3).
>>
>> 	* NEWS: Add note about pwritev2 and preadv2 inclusion.
>> 	* misc/Makefile (routines): Add preadv2, preadv64v2, pwritev2, and
>> 	pwritev64v2.
>> 	(tests): Add tst-preadvwritev2 and tst-preadvwritev64v2.
>> 	* misc/Versions (GLIBC_2.26): Add preadv2, preadv64v2, pwritev2, and
>> 	pwritev64v2.
>> 	* misc/preadv2.c: New file.
>> 	* misc/preadv64v2.c: Likewise.
>> 	* misc/pwritev2.c: Likewise.
>> 	* misc/pwritev64v2.c: Likewise.
>> 	* misc/tst-preadvwritev2.c: Likewise.
>> 	* misc/tst-preadvwritev64v2.c: Likewise.
>> 	* manual/llio.texi: Add preadv2 and pwritev2 documentation.
>> 	* misc/sys/uio.h [__USE_GNU && !__USE_FILE_OFFSET64] (preadv2): New
>> 	prototype.
>> 	[__USE_GNU && !__USE_FILE_OFFSET64] (pwritev2):	Likewise.
>> 	[__USE_GNU && __USE_FILE_OFFSET64] (preadv64v2): Likewise.
>> 	[__USE_GNU && __USE_FILE_OFFSET64] (pwritev64v2): Likewise.
>> 	* misc/tst-preadvwritev-common.c (PREADV): Define if not defined.
>> 	(PWRITEV): Likewise.
>> 	(do_test_with_offset): Use PREADV and PWRITEV macros and check for
>> 	ENOSYS.
>> 	* nptl/tst-cancel4.c (tf_pwritev2): New test.
>> 	(tf_preadv2): Likewise.
>> 	(tf_fsync): Add tf_pwritev2 and tf_preadv2.
>> 	* sysdeps/posix/preadv2.c: Likewise.
>> 	* sysdeps/posix/preadv64v2.c: Likewise.
>> 	* sysdeps/posix/pwritev2.c: Likewise.
>> 	* sysdeps/posix/pwritev64v2.c: Likewise.
>> 	* sysdeps/unix/sysv/linux/kernel-features.h: Add comment for syscall
>> 	support in kernel.
>> 	* sysdeps/unix/sysv/linux/preadv2.c: Likewise.
>> 	* sysdeps/unix/sysv/linux/preadv64v2.c: Likewise.
>> 	* sysdeps/unix/sysv/linux/pwritev2.c: Likewise.
>> 	* sysdeps/unix/sysv/linux/pwritev64v2.c: Likewise.
>> 	* sysdeps/unix/sysv/linux/preadv.c (preadv): Add libc_hidden_def.
>> 	* sysdeps/unix/sysv/linux/preadv64.c (preadv64): Likewise.
>> 	* sysdeps/unix/sysv/linux/pwritev.c (pwritev): Likewise.
>> 	* sysdeps/unix/sysv/linux/pwritev64.c (pwritev64): Likewise.
>> 	* sysdeps/unix/sysv/linux/bits/uio.h: Add supported preadv2/pwritev2
>> 	support flags on Linux.
>> 	* sysdeps/unix/sysv/linux/aarch64/libc.abilist (GLIBC_2.26): Add
>> 	preadv2, preadv64v2, pwritev2, pwritev64v2.
>> 	* sysdeps/unix/sysv/linux/alpha/libc.abilist (GLIBC_2.26): Likewise.
>> 	* sysdeps/unix/sysv/linux/arm/libc.abilist (GLIBC_2.26): Likewise.
>> 	* sysdeps/unix/sysv/linux/hppa/libc.abilist (GLIBC_2.26): Likewise.
>> 	* sysdeps/unix/sysv/linux/i386/libc.abilist (GLIBC_2.26): Likewise.
>> 	* sysdeps/unix/sysv/linux/ia64/libc.abilist (GLIBC_2.26): Likewise.
>> 	* sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist (GLIBC_2.26):
>> 	Likewise.
>> 	* sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist (GLIBC_2.26):
>> 	Likewise.
>> 	* sysdeps/unix/sysv/linux/microblaze/libc.abilist (GLIBC_2.26):
>> 	Likewise.
>> 	* sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist (GLIBC_2.26):
>> 	Likewise.
>> 	* sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist (GLIBC_2.26):
>> 	Likewise.
>> 	* sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist (GLIBC_2.26):
>> 	Likewise.
>> 	* sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist (GLIBC_2.26):
>> 	Likewise.
>> 	* sysdeps/unix/sysv/linux/nios2/libc.abilist (GLIBC_2.26): Likewise.
>> 	* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
>> 	(GLIBC_2.26): Likewise.
>> 	* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
>> 	(GLIBC_2.26): Likewise.
>> 	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist (GLIBC_2.26):
>> 	Likewise.
>> 	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist
>> 	(GLIBC_2.26): Likewise.
>> 	* sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist (GLIBC_2.26):
>> 	Likewise.
>> 	* sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist (GLIBC_2.26):
>> 	Likewise.
>> 	* sysdeps/unix/sysv/linux/sh/libc.abilist (GLIBC_2.26): Likewise.
>> 	* sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist (GLIBC_2.26):
>> 	Likewise.
>> 	* sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist (GLIBC_2.26):
>> 	Likewise.
>> 	* sysdeps/sysv/linux/tile/tilegx/tilegx32/libc.abilist (GLIBC_2.26):
>> 	Likewise.
>> 	* sysdeps/sysv/linux/tile/tilegx/tilegx64/libc.abilist (GLIBC_2.26):
>> 	Likewise.
>> 	* sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist (GLIBC_2.26):
>> 	Likewise.
>> 	* sysdeps/unix/sysv/linux/x86_64/64/libc.abilist (GLIBC_2.26):
>> 	Likewise.
>> 	* sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist (GLIBC_2.26):
>> 	Likewise.
>> ---
>>  ChangeLog                                          |  91 +++++++++++++++++
>>  NEWS                                               |   7 ++
>>  include/sys/uio.h                                  |   6 ++
>>  manual/llio.texi                                   | 109 +++++++++++++++++++++
>>  misc/Makefile                                      |   5 +-
>>  misc/Versions                                      |   3 +
>>  misc/preadv2.c                                     |  30 ++++++
>>  misc/preadv64v2.c                                  |  30 ++++++
>>  misc/pwritev2.c                                    |  30 ++++++
>>  misc/pwritev64v2.c                                 |  30 ++++++
>>  misc/sys/uio.h                                     |  41 ++++++++
>>  misc/tst-preadvwritev-common.c                     |  19 +++-
>>  misc/tst-preadvwritev2.c                           |  31 ++++++
>>  misc/tst-preadvwritev64v2.c                        |  33 +++++++
>>  nptl/tst-cancel4.c                                 |  71 ++++++++++++++
>>  sysdeps/posix/preadv2.c                            |  38 +++++++
>>  sysdeps/posix/preadv64v2.c                         |  37 +++++++
>>  sysdeps/posix/pwritev2.c                           |  38 +++++++
>>  sysdeps/posix/pwritev64v2.c                        |  38 +++++++
>>  sysdeps/unix/sysv/linux/aarch64/libc.abilist       |   5 +
>>  sysdeps/unix/sysv/linux/alpha/libc.abilist         |   5 +
>>  sysdeps/unix/sysv/linux/arm/libc.abilist           |   5 +
>>  sysdeps/unix/sysv/linux/bits/uio.h                 |   6 ++
>>  sysdeps/unix/sysv/linux/hppa/libc.abilist          |   5 +
>>  sysdeps/unix/sysv/linux/i386/libc.abilist          |   5 +
>>  sysdeps/unix/sysv/linux/ia64/libc.abilist          |   5 +
>>  sysdeps/unix/sysv/linux/kernel-features.h          |   5 +
>>  sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist |   5 +
>>  sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist   |   5 +
>>  sysdeps/unix/sysv/linux/microblaze/libc.abilist    |   5 +
>>  .../unix/sysv/linux/mips/mips32/fpu/libc.abilist   |   5 +
>>  .../unix/sysv/linux/mips/mips32/nofpu/libc.abilist |   5 +
>>  .../unix/sysv/linux/mips/mips64/n32/libc.abilist   |   5 +
>>  .../unix/sysv/linux/mips/mips64/n64/libc.abilist   |   5 +
>>  sysdeps/unix/sysv/linux/nios2/libc.abilist         |   5 +
>>  .../sysv/linux/powerpc/powerpc32/fpu/libc.abilist  |   5 +
>>  .../linux/powerpc/powerpc32/nofpu/libc.abilist     |   5 +
>>  .../sysv/linux/powerpc/powerpc64/libc-le.abilist   |   5 +
>>  .../unix/sysv/linux/powerpc/powerpc64/libc.abilist |   5 +
>>  sysdeps/unix/sysv/linux/preadv.c                   |   2 +
>>  sysdeps/unix/sysv/linux/preadv2.c                  |  55 +++++++++++
>>  sysdeps/unix/sysv/linux/preadv64.c                 |   2 +
>>  sysdeps/unix/sysv/linux/preadv64v2.c               |  55 +++++++++++
>>  sysdeps/unix/sysv/linux/pwrite64.c                 |   1 +
>>  sysdeps/unix/sysv/linux/pwritev.c                  |   2 +
>>  sysdeps/unix/sysv/linux/pwritev2.c                 |  51 ++++++++++
>>  sysdeps/unix/sysv/linux/pwritev64.c                |   2 +
>>  sysdeps/unix/sysv/linux/pwritev64v2.c              |  55 +++++++++++
>>  sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist  |   5 +
>>  sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist  |   5 +
>>  sysdeps/unix/sysv/linux/sh/libc.abilist            |   5 +
>>  sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist |   5 +
>>  sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist |   5 +
>>  .../sysv/linux/tile/tilegx/tilegx32/libc.abilist   |   5 +
>>  .../sysv/linux/tile/tilegx/tilegx64/libc.abilist   |   5 +
>>  sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist  |   5 +
>>  sysdeps/unix/sysv/linux/x86_64/64/libc.abilist     |   5 +
>>  sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist    |   5 +
>>  58 files changed, 1058 insertions(+), 5 deletions(-)
>>  create mode 100644 misc/preadv2.c
>>  create mode 100644 misc/preadv64v2.c
>>  create mode 100644 misc/pwritev2.c
>>  create mode 100644 misc/pwritev64v2.c
>>  create mode 100644 misc/tst-preadvwritev2.c
>>  create mode 100644 misc/tst-preadvwritev64v2.c
>>  create mode 100644 sysdeps/posix/preadv2.c
>>  create mode 100644 sysdeps/posix/preadv64v2.c
>>  create mode 100644 sysdeps/posix/pwritev2.c
>>  create mode 100644 sysdeps/posix/pwritev64v2.c
>>  create mode 100644 sysdeps/unix/sysv/linux/preadv2.c
>>  create mode 100644 sysdeps/unix/sysv/linux/preadv64v2.c
>>  create mode 100644 sysdeps/unix/sysv/linux/pwritev2.c
>>  create mode 100644 sysdeps/unix/sysv/linux/pwritev64v2.c
>>
>> diff --git a/NEWS b/NEWS
>> index 5558ca3..afad4b1 100644
>> --- a/NEWS
>> +++ b/NEWS
>> @@ -57,6 +57,13 @@ Version 2.26
>>    be added on next major revision of POSIX, so current support is enabled
>>    with _GNU_SOURCE.
>>  
>> +* New preadv2 and pwritev2 are added to libc.  They are Linux extensions to
>> +  preadv and pwritev with an additional flag argument where it is possible
>> +  to set high priority or use O_DSYNC or O_SYNC for an specific IO operation.
>> +  For complete support it requires Linux kernel version 4.6, otherwise a
>> +  compat implementation will be used (which refuses all flags and routes it
>> +  to preadv or pwritev).
>> +
>>  Security related changes:
>>  
>>  * The DNS stub resolver limits the advertised UDP buffer size to 1200 bytes,
>> diff --git a/include/sys/uio.h b/include/sys/uio.h
>> index f44ce18..20860bf 100644
>> --- a/include/sys/uio.h
>> +++ b/include/sys/uio.h
>> @@ -7,5 +7,11 @@ extern ssize_t __readv (int __fd, const struct iovec *__iovec,
>>  			int __count);
>>  extern ssize_t __writev (int __fd, const struct iovec *__iovec,
>>  			 int __count);
>> +
>> +/* Used for p{read,write}{v64}v2 implementation.  */
>> +libc_hidden_proto (preadv)
>> +libc_hidden_proto (preadv64)
>> +libc_hidden_proto (pwritev)
>> +libc_hidden_proto (pwritev64)
>>  #endif
>>  #endif
>> diff --git a/manual/llio.texi b/manual/llio.texi
>> index dae3754..404a966 100644
>> --- a/manual/llio.texi
>> +++ b/manual/llio.texi
>> @@ -756,6 +756,115 @@ When the source file is compiled using @code{_FILE_OFFSET_BITS == 64} on a
>>  @code{pwritev} and so transparently replaces the 32 bit interface.
>>  @end deftypefun
>>  
>> +@comment sys/uio.h
>> +@comment GNU
>> +@deftypefun ssize_t preadv2 (int @var{fd}, const struct iovec *@var{iov}, int @var{iovcnt}, off_t @var{offset}, int @var{flags})
>> +@safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}}
>> +@c This is a syscall for Linux v4.6.  The sysdeps/posix fallback emulation
>> +@c is also MT-Safe since it calls preadv.
>> +
>> +This function is similar to the @code{preadv} function, with the difference
>> +it adds an extra @var{flags} parameter of type @code{int}.  The supported
>> +@var{flags} are dependent of the underlying system.  For Linux it supports:
>> +
>> +@vtable @code
>> +@item RWF_HIPRI
>> +High priority request.  This adds a flag that tells the file system that
>> +this is a high priority request for which it is worth to poll the hardware.
>> +The flag is purely advisory and can be ignored if not supported.  The
>> +@var{fd} must be opened using @code{O_DIRECT}.
>> +
>> +@item RWF_DSYNC
>> +Per-IO synchronization as if the file was opened with @code{O_DSYNC} flag.
>> +
>> +@item RWF_SYNC
>> +Per-IO synchronization as if the file was opened with @code{O_SYNC} flag.
>> +@end vtable
>> +
>> +When the source file is compiled with @code{_FILE_OFFSET_BITS == 64} the
>> +@code{preadv2} function is in fact @code{preadv64v2} and the type
>> +@code{off_t} has 64 bits, which makes it possible to handle files up to
>> +@twoexp{63} bytes in length.
>> +
>> +The return value is a count of bytes (@emph{not} buffers) read, @math{0}
>> +indicating end-of-file, or @math{-1} indicating an error.  The possible
>> +errors are the same as in @code{preadv} with the addition of:
>> +
>> +@table @code
>> +
>> +@item EOPNOTSUPP
>> +
>> +@c The default sysdeps/posix code will return it for any flags value
>> +@c different than 0.
>> +An unsupported @var{flags} was used.
>> +
>> +@end table
>> +
>> +@end deftypefun
>> +
>> +@comment unistd.h
>> +@comment GNU
>> +@deftypefun ssize_t preadv64v2 (int @var{fd}, const struct iovec *@var{iov}, int @var{iovcnt}, off64_t @var{offset}, int @var{flags})
>> +@safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}}
>> +@c This is a syscall for Linux v4.6.  The sysdeps/posix fallback emulation
>> +@c is also MT-Safe since it calls preadv.
>> +
>> +This function is similar to the @code{preadv2} function with the difference
>> +is that the @var{offset} parameter is of type @code{off64_t} instead of
>> +@code{off_t}.  It makes it possible on 32 bit machines to address
>> +files larger than @twoexp{31} bytes and up to @twoexp{63} bytes.  The
>> +file descriptor @code{filedes} must be opened using @code{open64} since
>> +otherwise the large offsets possible with @code{off64_t} will lead to
>> +errors with a descriptor in small file mode.
>> +
>> +When the source file is compiled using @code{_FILE_OFFSET_BITS == 64} on a
>> +32 bit machine this function is actually available under the name
>> +@code{preadv2} and so transparently replaces the 32 bit interface.
>> +@end deftypefun
>> +
>> +
>> +@comment sys/uio.h
>> +@comment GNU
>> +@deftypefun ssize_t pwritev2 (int @var{fd}, const struct iovec *@var{iov}, int @var{iovcnt}, off_t @var{offset}, int @var{flags})
>> +@safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}}
>> +@c This is a syscall for Linux v4.6.  The sysdeps/posix fallback emulation
>> +@c is also MT-Safe since it calls pwritev.
>> +
>> +This function is similar to the @code{pwritev} function, with the difference
>> +it adds an extra @var{flags} parameter of type @code{int}.  The supported
>> +@var{flags} are dependent of the underlying system and for Linux it supports
>> +the same ones as for @code{preadv2}.
>> +
>> +When the source file is compiled with @code{_FILE_OFFSET_BITS == 64} the
>> +@code{pwritev2} function is in fact @code{pwritev64v2} and the type
>> +@code{off_t} has 64 bits, which makes it possible to handle files up to
>> +@twoexp{63} bytes in length.
>> +
>> +The return value is a count of bytes (@emph{not} buffers) write, @math{0}
>> +indicating end-of-file, or @math{-1} indicating an error.  The possible
>> +errors are the same as in @code{preadv2}.
>> +@end deftypefun
>> +
>> +@comment unistd.h
>> +@comment GNU
>> +@deftypefun ssize_t pwritev64v2 (int @var{fd}, const struct iovec *@var{iov}, int @var{iovcnt}, off64_t @var{offset}, int @var{flags})
>> +@safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}}
>> +@c This is a syscall for Linux v4.6.  The sysdeps/posix fallback emulation
>> +@c is also MT-Safe since it calls pwritev.
>> +
>> +This function is similar to the @code{pwritev2} function with the difference
>> +is that the @var{offset} parameter is of type @code{off64_t} instead of
>> +@code{off_t}.  It makes it possible on 32 bit machines to address
>> +files larger than @twoexp{31} bytes and up to @twoexp{63} bytes.  The
>> +file descriptor @code{filedes} must be opened using @code{open64} since
>> +otherwise the large offsets possible with @code{off64_t} will lead to
>> +errors with a descriptor in small file mode.
>> +
>> +When the source file is compiled using @code{_FILE_OFFSET_BITS == 64} on a
>> +32 bit machine this function is actually available under the name
>> +@code{pwritev2} and so transparently replaces the 32 bit interface.
>> +@end deftypefun
>> +
>>  
>>  @node File Position Primitive
>>  @section Setting the File Position of a Descriptor
>> diff --git a/misc/Makefile b/misc/Makefile
>> index 622da67..bed46d7 100644
>> --- a/misc/Makefile
>> +++ b/misc/Makefile
>> @@ -39,6 +39,7 @@ headers	:= sys/uio.h bits/uio.h sys/ioctl.h bits/ioctls.h bits/ioctl-types.h \
>>  
>>  routines := brk sbrk sstk ioctl \
>>  	    readv writev preadv preadv64 pwritev pwritev64 \
>> +	    preadv2 preadv64v2 pwritev2 pwritev64v2 \
>>  	    setreuid setregid \
>>  	    seteuid setegid \
>>  	    getpagesize \
>> @@ -79,7 +80,9 @@ gpl2lgpl := error.c error.h
>>  tests := tst-dirname tst-tsearch tst-fdset tst-efgcvt tst-mntent tst-hsearch \
>>  	 tst-error1 tst-pselect tst-insremque tst-mntent2 bug-hsearch1 \
>>  	 tst-mntent-blank-corrupt tst-mntent-blank-passno bug18240 \
>> -	 tst-preadvwritev tst-preadvwritev64 tst-makedev tst-empty \
>> +	 tst-preadvwritev tst-preadvwritev64 tst-preadvwritev2 \
>> +	 tst-preadvwritev64v2 \
>> +	 tst-makedev tst-empty \
>>  	 tst-atomic tst-atomic-long
>>  tests-static := tst-empty
>>  
>> diff --git a/misc/Versions b/misc/Versions
>> index f2c90ff..bafda78 100644
>> --- a/misc/Versions
>> +++ b/misc/Versions
>> @@ -155,6 +155,9 @@ libc {
>>    GLIBC_2.25 {
>>      gnu_dev_major; gnu_dev_minor; gnu_dev_makedev;
>>    }
>> +  GLIBC_2.26 {
>> +    preadv2; preadv64v2; pwritev2; pwritev64v2;
>> +  }
>>    GLIBC_PRIVATE {
>>      __madvise;
>>      __mktemp;
>> diff --git a/misc/preadv2.c b/misc/preadv2.c
>> new file mode 100644
>> index 0000000..a62dcaa
>> --- /dev/null
>> +++ b/misc/preadv2.c
>> @@ -0,0 +1,30 @@
>> +/* Default implementation of preadv2.
>> +   Copyright (C) 2017 Free Software Foundation, Inc.
>> +   This file is part of the GNU C Library.
>> +
>> +   The GNU C Library is free software; you can redistribute it and/or
>> +   modify it under the terms of the GNU Lesser General Public
>> +   License as published by the Free Software Foundation; either
>> +   version 2.1 of the License, or (at your option) any later version.
>> +
>> +   The GNU C Library is distributed in the hope that it will be useful,
>> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
>> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>> +   Lesser General Public License for more details.
>> +
>> +   You should have received a copy of the GNU Lesser General Public
>> +   License along with the GNU C Library; if not, see
>> +   <http://www.gnu.org/licenses/>.  */
>> +
>> +#include <sys/uio.h>
>> +
>> +/* Same as preadv but with an additional flags argument.  */
>> +ssize_t
>> +preadv2 (int fd, const struct iovec *vector, int count, off_t offset,
>> +	 int flags)
>> +{
>> +  __set_errno (ENOSYS);
>> +  return -1;
>> +}
>> +
>> +stub_warning (preadv2)
>> diff --git a/misc/preadv64v2.c b/misc/preadv64v2.c
>> new file mode 100644
>> index 0000000..a802c2f
>> --- /dev/null
>> +++ b/misc/preadv64v2.c
>> @@ -0,0 +1,30 @@
>> +/* Default implementation of preadv2 (LFS version).
>> +   Copyright (C) 2017 Free Software Foundation, Inc.
>> +   This file is part of the GNU C Library.
>> +
>> +   The GNU C Library is free software; you can redistribute it and/or
>> +   modify it under the terms of the GNU Lesser General Public
>> +   License as published by the Free Software Foundation; either
>> +   version 2.1 of the License, or (at your option) any later version.
>> +
>> +   The GNU C Library is distributed in the hope that it will be useful,
>> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
>> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>> +   Lesser General Public License for more details.
>> +
>> +   You should have received a copy of the GNU Lesser General Public
>> +   License along with the GNU C Library; if not, see
>> +   <http://www.gnu.org/licenses/>.  */
>> +
>> +#include <sys/uio.h>
>> +
>> +/* Same as preadv64 but with an addional flag argument.  */
>> +ssize_t
>> +preadv64v2 (int fd, const struct iovec *vector, int count, off64_t offset,
>> +	    int flags)
>> +{
>> +  __set_errno (ENOSYS);
>> +  return -1;
>> +}
>> +
>> +stub_warning (preadv64v2)
>> diff --git a/misc/pwritev2.c b/misc/pwritev2.c
>> new file mode 100644
>> index 0000000..b9e0727
>> --- /dev/null
>> +++ b/misc/pwritev2.c
>> @@ -0,0 +1,30 @@
>> +/* Default implementation of pwritev2.
>> +   Copyright (C) 2017 Free Software Foundation, Inc.
>> +   This file is part of the GNU C Library.
>> +
>> +   The GNU C Library is free software; you can redistribute it and/or
>> +   modify it under the terms of the GNU Lesser General Public
>> +   License as published by the Free Software Foundation; either
>> +   version 2.1 of the License, or (at your option) any later version.
>> +
>> +   The GNU C Library is distributed in the hope that it will be useful,
>> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
>> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>> +   Lesser General Public License for more details.
>> +
>> +   You should have received a copy of the GNU Lesser General Public
>> +   License along with the GNU C Library; if not, see
>> +   <http://www.gnu.org/licenses/>.  */
>> +
>> +#include <sys/uio.h>
>> +
>> +/* Same as pwritev but with an additional flags argument.  */
>> +ssize_t
>> +pwritev2 (int fd, const struct iovec *vector, int count, off_t offset,
>> +	  int flags)
>> +{
>> +  __set_errno (ENOSYS);
>> +  return -1;
>> +}
>> +
>> +stub_warning (pwritev2)
>> diff --git a/misc/pwritev64v2.c b/misc/pwritev64v2.c
>> new file mode 100644
>> index 0000000..1f874f0
>> --- /dev/null
>> +++ b/misc/pwritev64v2.c
>> @@ -0,0 +1,30 @@
>> +/* Default implementation of pwritev2 (LFS version).
>> +   Copyright (C) 2017 Free Software Foundation, Inc.
>> +   This file is part of the GNU C Library.
>> +
>> +   The GNU C Library is free software; you can redistribute it and/or
>> +   modify it under the terms of the GNU Lesser General Public
>> +   License as published by the Free Software Foundation; either
>> +   version 2.1 of the License, or (at your option) any later version.
>> +
>> +   The GNU C Library is distributed in the hope that it will be useful,
>> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
>> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>> +   Lesser General Public License for more details.
>> +
>> +   You should have received a copy of the GNU Lesser General Public
>> +   License along with the GNU C Library; if not, see
>> +   <http://www.gnu.org/licenses/>.  */
>> +
>> +#include <sys/uio.h>
>> +
>> +/* Same as preadv64 but with an addional flag argument.  */
>> +ssize_t
>> +pwritev64v2 (int fd, const struct iovec *vector, int count, off64_t offset,
>> +	     int flags)
>> +{
>> +  __set_errno (ENOSYS);
>> +  return -1;
>> +}
>> +
>> +stub_warning (pwritev64v2)
>> diff --git a/misc/sys/uio.h b/misc/sys/uio.h
>> index e80f013..66c22f0 100644
>> --- a/misc/sys/uio.h
>> +++ b/misc/sys/uio.h
>> @@ -76,6 +76,7 @@ extern ssize_t preadv (int __fd, const struct iovec *__iovec, int __count,
>>     __THROW.  */
>>  extern ssize_t pwritev (int __fd, const struct iovec *__iovec, int __count,
>>  			__off_t __offset) __wur;
>> +
>>  # else
>>  #  ifdef __REDIRECT
>>  extern ssize_t __REDIRECT (preadv, (int __fd, const struct iovec *__iovec,
>> @@ -117,6 +118,46 @@ extern ssize_t pwritev64 (int __fd, const struct iovec *__iovec, int __count,
>>  # endif
>>  #endif	/* Use misc.  */
>>  
>> +
>> +#ifdef __USE_GNU
>> +# ifndef __USE_FILE_OFFSET64
>> +/* Same as preadv but with an additional flag argumenti defined at uio.h.  */
>> +extern ssize_t preadv2 (int __fp, const struct iovec *__iovec, int __count,
>> +			__off_t __offset, int ___flags) __wur;
>> +
>> +/* Same as preadv but with an additional flag argument defined at uio.h.  */
>> +extern ssize_t pwritev2 (int __fd, const struct iovec *__iodev, int __count,
>> +			 __off_t __offset, int __flags) __wur;
>> +
>> +# else
>> +#  ifdef __REDIRECT
>> +extern ssize_t __REDIRECT (pwritev2, (int __fd, const struct iovec *__iovec,
>> +				      int __count, __off64_t __offset,
>> +				      int __flags),
>> +			   pwritev64v2) __wur;
>> +extern ssize_t __REDIRECT (preadv2, (int __fd, const struct iovec *__iovec,
>> +				     int __count, __off64_t __offset,
>> +				     int __flags),
>> +			   preadv64v2) __wur;
>> +#  else
>> +#   define preadv2 preadv64v2
>> +#   define pwritev2 pwritev64v2
>> +#  endif
>> +# endif
>> +
>> +# ifdef __USE_LARGEFILE64
>> +/* Same as preadv but with an additional flag argumenti defined at uio.h.  */
>> +extern ssize_t preadv64v2 (int __fp, const struct iovec *__iovec,
>> +			   int __count, __off64_t __offset,
>> +			   int ___flags) __wur;
>> +
>> +/* Same as preadv but with an additional flag argument defined at uio.h.  */
>> +extern ssize_t pwritev64v2 (int __fd, const struct iovec *__iodev,
>> +			    int __count, __off64_t __offset,
>> +			    int __flags) __wur;
>> +# endif
>> +#endif /* Use GNU.  */
>> +
>>  __END_DECLS
>>  
>>  #endif /* sys/uio.h */
>> diff --git a/misc/tst-preadvwritev-common.c b/misc/tst-preadvwritev-common.c
>> index 5540dfb..676d495 100644
>> --- a/misc/tst-preadvwritev-common.c
>> +++ b/misc/tst-preadvwritev-common.c
>> @@ -18,6 +18,7 @@
>>  
>>  #include <stdio.h>
>>  #include <stdint.h>
>> +#include <errno.h>
>>  #include <string.h>
>>  #include <sys/uio.h>
>>  #include <sys/stat.h>
>> @@ -39,6 +40,16 @@ do_prepare (int argc, char **argv)
>>  }
>>  #define PREPARE do_prepare
>>  
>> +#ifndef PREADV
>> +# define PREADV(__fd, __iov, __iovcnt, __offset) \
>> +  preadv (__fd, __iov, __iovcnt, __offset)
>> +#endif
>> +
>> +#ifndef PWRITEV
>> +# define PWRITEV(__fd, __iov, __iovcnt, __offset) \
>> +  pwritev (__fd, __iov, __iovcnt, __offset)
>> +#endif
>> +
>>  static int
>>  do_test_with_offset (off_t offset)
>>  {
>> @@ -58,13 +69,13 @@ do_test_with_offset (off_t offset)
>>    iov[1].iov_base = buf2;
>>    iov[1].iov_len = sizeof buf2;
>>  
>> -  ret = pwritev (temp_fd, iov, 2, offset);
>> +  ret = PWRITEV (temp_fd, iov, 2, offset);
>>    if (ret == -1)
>>      FAIL_RET ("first pwritev returned -1");
>>    if (ret != (sizeof buf1 + sizeof buf2))
>>      FAIL_RET ("first pwritev returned an unexpected value");
>>  
>> -  ret = pwritev (temp_fd, iov, 2, sizeof buf1 + sizeof buf2 + offset);
>> +  ret = PWRITEV (temp_fd, iov, 2, sizeof buf1 + sizeof buf2 + offset);
>>    if (ret == -1)
>>      FAIL_RET ("second pwritev returned -1");
>>    if (ret != (sizeof buf1 + sizeof buf2))
>> @@ -82,7 +93,7 @@ do_test_with_offset (off_t offset)
>>    iov[1].iov_len = sizeof buf4;
>>  
>>    /* Now read two buffer with 32 and 64 bytes respectively.  */
>> -  ret = preadv (temp_fd, iov, 2, offset);
>> +  ret = PREADV (temp_fd, iov, 2, offset);
>>    if (ret == -1)
>>      FAIL_RET ("first preadv returned -1");
>>    if (ret != (sizeof buf3 + sizeof buf4))
>> @@ -93,7 +104,7 @@ do_test_with_offset (off_t offset)
>>    if (memcmp (buf2, buf4, sizeof buf2) != 0)
>>      FAIL_RET ("second buffer from first preadv different than expected");
>>  
>> -  ret = preadv (temp_fd, iov, 2, sizeof buf3 + sizeof buf4 + offset);
>> +  ret = PREADV (temp_fd, iov, 2, sizeof buf3 + sizeof buf4 + offset);
>>    if (ret == -1)
>>      FAIL_RET ("second preadv returned -1");
>>    if (ret != (sizeof buf3 + sizeof buf4))
>> diff --git a/misc/tst-preadvwritev2.c b/misc/tst-preadvwritev2.c
>> new file mode 100644
>> index 0000000..cf36272
>> --- /dev/null
>> +++ b/misc/tst-preadvwritev2.c
>> @@ -0,0 +1,31 @@
>> +/* Tests for preadv2 and pwritev2.
>> +   Copyright (C) 2016-2017 Free Software Foundation, Inc.
>> +   This file is part of the GNU C Library.
>> +
>> +   The GNU C Library is free software; you can redistribute it and/or
>> +   modify it under the terms of the GNU Lesser General Public
>> +   License as published by the Free Software Foundation; either
>> +   version 2.1 of the License, or (at your option) any later version.
>> +
>> +   The GNU C Library is distributed in the hope that it will be useful,
>> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
>> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>> +   Lesser General Public License for more details.
>> +
>> +   You should have received a copy of the GNU Lesser General Public
>> +   License along with the GNU C Library; if not, see
>> +   <http://www.gnu.org/licenses/>.  */
>> +
>> +#define PREADV(__fd, __iov, __iovcnt, __offset) \
>> +  preadv2 (__fd, __iov, __iovcnt, __offset, 0)
>> +
>> +#define PWRITEV(__fd, __iov, __iovcnt, __offset) \
>> +  pwritev2 (__fd, __iov, __iovcnt, __offset, 0)
>> +
>> +#include "tst-preadvwritev-common.c"
>> +
>> +static int
>> +do_test (void)
>> +{
>> +  return do_test_with_offset (0);
>> +}
>> diff --git a/misc/tst-preadvwritev64v2.c b/misc/tst-preadvwritev64v2.c
>> new file mode 100644
>> index 0000000..8d0c48e
>> --- /dev/null
>> +++ b/misc/tst-preadvwritev64v2.c
>> @@ -0,0 +1,33 @@
>> +/* Tests for preadv2 and pwritev2 (LFS version).
>> +   Copyright (C) 2017 Free Software Foundation, Inc.
>> +   This file is part of the GNU C Library.
>> +
>> +   The GNU C Library is free software; you can redistribute it and/or
>> +   modify it under the terms of the GNU Lesser General Public
>> +   License as published by the Free Software Foundation; either
>> +   version 2.1 of the License, or (at your option) any later version.
>> +
>> +   The GNU C Library is distributed in the hope that it will be useful,
>> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
>> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>> +   Lesser General Public License for more details.
>> +
>> +   You should have received a copy of the GNU Lesser General Public
>> +   License along with the GNU C Library; if not, see
>> +   <http://www.gnu.org/licenses/>.  */
>> +
>> +#define _FILE_OFFSET_BITS 64
>> +
>> +#define PREADV(__fd, __iov, __iovcnt, __offset) \
>> +  preadv2 (__fd, __iov, __iovcnt, __offset, 0)
>> +
>> +#define PWRITEV(__fd, __iov, __iovcnt, __offset) \
>> +  pwritev2 (__fd, __iov, __iovcnt, __offset, 0)
>> +
>> +#include "tst-preadvwritev-common.c"
>> +
>> +static int
>> +do_test (void)
>> +{
>> +  return do_test_with_offset (0);
>> +}
>> diff --git a/nptl/tst-cancel4.c b/nptl/tst-cancel4.c
>> index e66961f..7a560a1 100644
>> --- a/nptl/tst-cancel4.c
>> +++ b/nptl/tst-cancel4.c
>> @@ -1079,6 +1079,75 @@ tf_pwritev (void *arg)
>>  }
>>  
>>  static void *
>> +tf_pwritev2 (void *arg)
>> +{
>> +  int fd;
>> +
>> +  if (arg == NULL)
>> +    /* XXX If somebody can provide a portable test case in which pwritev2
>> +       blocks we can enable this test to run in both rounds.  */
>> +    abort ();
>> +
>> +  errno = 0;
>> +
>> +  char fname[] = "/tmp/tst-cancel4-fd-XXXXXX";
>> +  tempfd = fd = mkstemp (fname);
>> +  if (fd == -1)
>> +    FAIL_EXIT1 ("mkstemp: %m");
>> +  unlink (fname);
>> +
>> +  xpthread_barrier_wait (&b2);
>> +
>> +  xpthread_barrier_wait (&b2);
>> +
>> +  ssize_t s;
>> +  pthread_cleanup_push (cl, NULL);
>> +
>> +  char buf[WRITE_BUFFER_SIZE];
>> +  memset (buf, '\0', sizeof (buf));
>> +  struct iovec iov[1] = { [0] = { .iov_base = buf, .iov_len = sizeof (buf) } };
>> +  s = pwritev2 (fd, iov, 1, 0, 0);
>> +
>> +  pthread_cleanup_pop (0);
>> +
>> +  FAIL_EXIT1 ("pwritev2 returns with %zd", s);
>> +}
>> +
>> +static void *
>> +tf_preadv2 (void *arg)
>> +{
>> +  int fd;
>> +
>> +  if (arg == NULL)
>> +    /* XXX If somebody can provide a portable test case in which preadv2
>> +       blocks we can enable this test to run in both rounds.  */
>> +    abort ();
>> +
>> +  errno = 0;
>> +
>> +  char fname[] = "/tmp/tst-cancel4-fd-XXXXXX";
>> +  tempfd = fd = mkstemp (fname);
>> +  if (fd == -1)
>> +    FAIL_EXIT1 ("mkstemp failed: %m");
>> +  unlink (fname);
>> +
>> +  xpthread_barrier_wait (&b2);
>> +
>> +  xpthread_barrier_wait (&b2);
>> +
>> +  ssize_t s;
>> +  pthread_cleanup_push (cl, NULL);
>> +
>> +  char buf[100];
>> +  struct iovec iov[1] = { [0] = { .iov_base = buf, .iov_len = sizeof (buf) } };
>> +  s = preadv2 (fd, iov, 1, 0, 0);
>> +
>> +  pthread_cleanup_pop (0);
>> +
>> +  FAIL_EXIT1 ("preadv2 returns with %zd", s);
>> +}
>> +
>> +static void *
>>  tf_fsync (void *arg)
>>  {
>>    if (arg == NULL)
>> @@ -1473,7 +1542,9 @@ struct cancel_tests tests[] =
>>    ADD_TEST (recvfrom, 2, 0),
>>    ADD_TEST (recvmsg, 2, 0),
>>    ADD_TEST (preadv, 2, 1),
>> +  ADD_TEST (preadv2, 2, 1),
>>    ADD_TEST (pwritev, 2, 1),
>> +  ADD_TEST (pwritev2, 2, 1),
>>    ADD_TEST (open, 2, 1),
>>    ADD_TEST (close, 2, 1),
>>    ADD_TEST (pread, 2, 1),
>> diff --git a/sysdeps/posix/preadv2.c b/sysdeps/posix/preadv2.c
>> new file mode 100644
>> index 0000000..2a7cf11
>> --- /dev/null
>> +++ b/sysdeps/posix/preadv2.c
>> @@ -0,0 +1,38 @@
>> +/* Generic version of preadv2.
>> +   Copyright (C) 2017 Free Software Foundation, Inc.
>> +   This file is part of the GNU C Library.
>> +
>> +   The GNU C Library is free software; you can redistribute it and/or
>> +   modify it under the terms of the GNU Lesser General Public
>> +   License as published by the Free Software Foundation; either
>> +   version 2.1 of the License, or (at your option) any later version.
>> +
>> +   The GNU C Library is distributed in the hope that it will be useful,
>> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
>> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>> +   Lesser General Public License for more details.
>> +
>> +   You should have received a copy of the GNU Lesser General Public
>> +   License along with the GNU C Library; if not, see
>> +   <http://www.gnu.org/licenses/>.  */
>> +
>> +#include <unistd.h>
>> +#include <sys/uio.h>
>> +
>> +#ifndef __OFF_T_MATCHES_OFF64_T
>> +
>> +/* Since we define no flags for preadv2 just route to preadv.  */
>> +ssize_t
>> +preadv2 (int fd, const struct iovec *vector, int count, OFF_T offset,
>> +	 int flags)
>> +{
>> +  if (flags != 0)
>> +    {
>> +      __set_errno (EOPNOTSUPP);
>> +      return -1;
>> +    }
>> +
>> +  return preadv (fd, vector, count, offset);
>> +}
>> +
>> +#endif
>> diff --git a/sysdeps/posix/preadv64v2.c b/sysdeps/posix/preadv64v2.c
>> new file mode 100644
>> index 0000000..e084f3f
>> --- /dev/null
>> +++ b/sysdeps/posix/preadv64v2.c
>> @@ -0,0 +1,37 @@
>> +/* Generic version of preadv2.
>> +   Copyright (C) 2017 Free Software Foundation, Inc.
>> +   This file is part of the GNU C Library.
>> +
>> +   The GNU C Library is free software; you can redistribute it and/or
>> +   modify it under the terms of the GNU Lesser General Public
>> +   License as published by the Free Software Foundation; either
>> +   version 2.1 of the License, or (at your option) any later version.
>> +
>> +   The GNU C Library is distributed in the hope that it will be useful,
>> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
>> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>> +   Lesser General Public License for more details.
>> +
>> +   You should have received a copy of the GNU Lesser General Public
>> +   License along with the GNU C Library; if not, see
>> +   <http://www.gnu.org/licenses/>.  */
>> +
>> +#include <unistd.>
>> +#include <sys/uio.h>
>> +
>> +ssize_t
>> +preadv64v2 (int fd, const struct iovec *vector, int count, OFF_T offset,
>> +	    int flags)
>> +{
>> +  if (flags != 0)
>> +    {
>> +      __set_errno (EOPNOTSUPP);
>> +      return -1;
>> +    }
>> +
>> +  return preadv64 (fd, vector, count, offset);
>> +}
>> +
>> +#ifdef __OFF_T_MATCHES_OFF64_T
>> +strong_alias (preadv64v2, preadv2)
>> +#endif
>> diff --git a/sysdeps/posix/pwritev2.c b/sysdeps/posix/pwritev2.c
>> new file mode 100644
>> index 0000000..5b7650c
>> --- /dev/null
>> +++ b/sysdeps/posix/pwritev2.c
>> @@ -0,0 +1,38 @@
>> +/* Generic version of pwritev2.
>> +   Copyright (C) 2017 Free Software Foundation, Inc.
>> +   This file is part of the GNU C Library.
>> +
>> +   The GNU C Library is free software; you can redistribute it and/or
>> +   modify it under the terms of the GNU Lesser General Public
>> +   License as published by the Free Software Foundation; either
>> +   version 2.1 of the License, or (at your option) any later version.
>> +
>> +   The GNU C Library is distributed in the hope that it will be useful,
>> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
>> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>> +   Lesser General Public License for more details.
>> +
>> +   You should have received a copy of the GNU Lesser General Public
>> +   License along with the GNU C Library; if not, see
>> +   <http://www.gnu.org/licenses/>.  */
>> +
>> +#include <unistd.h>
>> +#include <sys/uio.h>
>> +
>> +#ifndef __OFF_T_MATCHES_OFF64_T
>> +
>> +/* Since we define no flags for pwritev2 just route to pwritev.  */
>> +ssize_t
>> +pwritev2 (int fd, const struct iovec *vector, int count, OFF_T offset,
>> +	  int flags)
>> +{
>> +  if (flags != 0)
>> +    {
>> +      __set_errno (EOPNOTSUPP);
>> +      return -1;
>> +    }
>> +
>> +  return pwritev (fd, vector, count, offset);
>> +}
>> +
>> +#endif
>> diff --git a/sysdeps/posix/pwritev64v2.c b/sysdeps/posix/pwritev64v2.c
>> new file mode 100644
>> index 0000000..d9727b9
>> --- /dev/null
>> +++ b/sysdeps/posix/pwritev64v2.c
>> @@ -0,0 +1,38 @@
>> +/* Generic version of pwritev2.
>> +   Copyright (C) 2017 Free Software Foundation, Inc.
>> +   This file is part of the GNU C Library.
>> +
>> +   The GNU C Library is free software; you can redistribute it and/or
>> +   modify it under the terms of the GNU Lesser General Public
>> +   License as published by the Free Software Foundation; either
>> +   version 2.1 of the License, or (at your option) any later version.
>> +
>> +   The GNU C Library is distributed in the hope that it will be useful,
>> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
>> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>> +   Lesser General Public License for more details.
>> +
>> +   You should have received a copy of the GNU Lesser General Public
>> +   License along with the GNU C Library; if not, see
>> +   <http://www.gnu.org/licenses/>.  */
>> +
>> +#include <unistd.h>
>> +#include <sys/uio.h>
>> +
>> +/* Since we define no flags for pwritev2 just route to pwritev.  */ 
>> +ssize_t
>> +pwritev64v2 (int fd, const struct iovec *vector, int count, OFF_T offset,
>> +	     int flags)
>> +{
>> +  if (flags != 0)
>> +    {
>> +      __set_errno (EOPNOTSUPP);
>> +      return -1;
>> +    }
>> +
>> +  return pwritev64 (fd, vector, count, offset);
>> +}
>> +
>> +#ifdef __OFF_T_MATCHES_OFF64_T
>> +strong_alias (pwritev64v2, pwritev2)
>> +#endif
>> diff --git a/sysdeps/unix/sysv/linux/aarch64/libc.abilist b/sysdeps/unix/sysv/linux/aarch64/libc.abilist
>> index 58d768c..296f2a5 100644
>> --- a/sysdeps/unix/sysv/linux/aarch64/libc.abilist
>> +++ b/sysdeps/unix/sysv/linux/aarch64/libc.abilist
>> @@ -2097,3 +2097,8 @@ GLIBC_2.25 getrandom F
>>  GLIBC_2.25 strfromd F
>>  GLIBC_2.25 strfromf F
>>  GLIBC_2.25 strfroml F
>> +GLIBC_2.26 GLIBC_2.26 A
>> +GLIBC_2.26 preadv2 F
>> +GLIBC_2.26 preadv64v2 F
>> +GLIBC_2.26 pwritev2 F
>> +GLIBC_2.26 pwritev64v2 F
>> diff --git a/sysdeps/unix/sysv/linux/alpha/libc.abilist b/sysdeps/unix/sysv/linux/alpha/libc.abilist
>> index 906050d..8006e72 100644
>> --- a/sysdeps/unix/sysv/linux/alpha/libc.abilist
>> +++ b/sysdeps/unix/sysv/linux/alpha/libc.abilist
>> @@ -2008,6 +2008,11 @@ GLIBC_2.25 getrandom F
>>  GLIBC_2.25 strfromd F
>>  GLIBC_2.25 strfromf F
>>  GLIBC_2.25 strfroml F
>> +GLIBC_2.26 GLIBC_2.26 A
>> +GLIBC_2.26 preadv2 F
>> +GLIBC_2.26 preadv64v2 F
>> +GLIBC_2.26 pwritev2 F
>> +GLIBC_2.26 pwritev64v2 F
>>  GLIBC_2.3 GLIBC_2.3 A
>>  GLIBC_2.3 __ctype_b_loc F
>>  GLIBC_2.3 __ctype_tolower_loc F
>> diff --git a/sysdeps/unix/sysv/linux/arm/libc.abilist b/sysdeps/unix/sysv/linux/arm/libc.abilist
>> index 66112dd..29f9688 100644
>> --- a/sysdeps/unix/sysv/linux/arm/libc.abilist
>> +++ b/sysdeps/unix/sysv/linux/arm/libc.abilist
>> @@ -98,6 +98,11 @@ GLIBC_2.25 getrandom F
>>  GLIBC_2.25 strfromd F
>>  GLIBC_2.25 strfromf F
>>  GLIBC_2.25 strfroml F
>> +GLIBC_2.26 GLIBC_2.26 A
>> +GLIBC_2.26 preadv2 F
>> +GLIBC_2.26 preadv64v2 F
>> +GLIBC_2.26 pwritev2 F
>> +GLIBC_2.26 pwritev64v2 F
>>  GLIBC_2.4 GLIBC_2.4 A
>>  GLIBC_2.4 _Exit F
>>  GLIBC_2.4 _IO_2_1_stderr_ D 0xa0
>> diff --git a/sysdeps/unix/sysv/linux/bits/uio.h b/sysdeps/unix/sysv/linux/bits/uio.h
>> index 1583f04..d5701f8 100644
>> --- a/sysdeps/unix/sysv/linux/bits/uio.h
>> +++ b/sysdeps/unix/sysv/linux/bits/uio.h
>> @@ -69,4 +69,10 @@ extern ssize_t process_vm_writev (pid_t __pid, const struct iovec *__lvec,
>>  __END_DECLS
>>  
>>  # endif
>> +
>> +/* Flags for preadv2/pwritev2: */
>> +#define RWF_HIPRI	0x00000001 /* High priority request.  */
>> +#define RWF_DSYNC	0x00000002 /* per-IO O_DSYNC.  */
>> +#define RWF_SYNC	0x00000004 /* per-IO O_SYNC.  */
>> +
>>  #endif
>> diff --git a/sysdeps/unix/sysv/linux/hppa/libc.abilist b/sysdeps/unix/sysv/linux/hppa/libc.abilist
>> index 3ddadd2..e9cfbaf 100644
>> --- a/sysdeps/unix/sysv/linux/hppa/libc.abilist
>> +++ b/sysdeps/unix/sysv/linux/hppa/libc.abilist
>> @@ -1862,6 +1862,11 @@ GLIBC_2.25 getrandom F
>>  GLIBC_2.25 strfromd F
>>  GLIBC_2.25 strfromf F
>>  GLIBC_2.25 strfroml F
>> +GLIBC_2.26 GLIBC_2.26 A
>> +GLIBC_2.26 preadv2 F
>> +GLIBC_2.26 preadv64v2 F
>> +GLIBC_2.26 pwritev2 F
>> +GLIBC_2.26 pwritev64v2 F
>>  GLIBC_2.3 GLIBC_2.3 A
>>  GLIBC_2.3 __ctype_b_loc F
>>  GLIBC_2.3 __ctype_tolower_loc F
>> diff --git a/sysdeps/unix/sysv/linux/i386/libc.abilist b/sysdeps/unix/sysv/linux/i386/libc.abilist
>> index 977ab90..c6ad3c3 100644
>> --- a/sysdeps/unix/sysv/linux/i386/libc.abilist
>> +++ b/sysdeps/unix/sysv/linux/i386/libc.abilist
>> @@ -2020,6 +2020,11 @@ GLIBC_2.25 getrandom F
>>  GLIBC_2.25 strfromd F
>>  GLIBC_2.25 strfromf F
>>  GLIBC_2.25 strfroml F
>> +GLIBC_2.26 GLIBC_2.26 A
>> +GLIBC_2.26 preadv2 F
>> +GLIBC_2.26 preadv64v2 F
>> +GLIBC_2.26 pwritev2 F
>> +GLIBC_2.26 pwritev64v2 F
>>  GLIBC_2.3 GLIBC_2.3 A
>>  GLIBC_2.3 __ctype_b_loc F
>>  GLIBC_2.3 __ctype_tolower_loc F
>> diff --git a/sysdeps/unix/sysv/linux/ia64/libc.abilist b/sysdeps/unix/sysv/linux/ia64/libc.abilist
>> index c7edb9a..d0055a2 100644
>> --- a/sysdeps/unix/sysv/linux/ia64/libc.abilist
>> +++ b/sysdeps/unix/sysv/linux/ia64/libc.abilist
>> @@ -1884,6 +1884,11 @@ GLIBC_2.25 getrandom F
>>  GLIBC_2.25 strfromd F
>>  GLIBC_2.25 strfromf F
>>  GLIBC_2.25 strfroml F
>> +GLIBC_2.26 GLIBC_2.26 A
>> +GLIBC_2.26 preadv2 F
>> +GLIBC_2.26 preadv64v2 F
>> +GLIBC_2.26 pwritev2 F
>> +GLIBC_2.26 pwritev64v2 F
>>  GLIBC_2.3 GLIBC_2.3 A
>>  GLIBC_2.3 __ctype_b_loc F
>>  GLIBC_2.3 __ctype_tolower_loc F
>> diff --git a/sysdeps/unix/sysv/linux/kernel-features.h b/sysdeps/unix/sysv/linux/kernel-features.h
>> index b981466..8ee1af7 100644
>> --- a/sysdeps/unix/sysv/linux/kernel-features.h
>> +++ b/sysdeps/unix/sysv/linux/kernel-features.h
>> @@ -137,3 +137,8 @@
>>  /* Support for SysV IPC through wired syscalls.  All supported architectures
>>     either support ipc syscall and/or all the ipc correspondent syscalls.  */
>>  #define __ASSUME_DIRECT_SYSVIPC_SYSCALLS	1
>> +
>> +/* Support for p{read,write}v2 was added in 4.6.  However Linux default
>> +   implementation does not assume the __ASSUME_* and instead use a fallback
>> +   implementation based on p{read,write}v and returning an error for
>> +   non supported flags.  */
>> diff --git a/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist b/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
>> index 450be4e..3777676 100644
>> --- a/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
>> +++ b/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
>> @@ -99,6 +99,11 @@ GLIBC_2.25 getrandom F
>>  GLIBC_2.25 strfromd F
>>  GLIBC_2.25 strfromf F
>>  GLIBC_2.25 strfroml F
>> +GLIBC_2.26 GLIBC_2.26 A
>> +GLIBC_2.26 preadv2 F
>> +GLIBC_2.26 preadv64v2 F
>> +GLIBC_2.26 pwritev2 F
>> +GLIBC_2.26 pwritev64v2 F
>>  GLIBC_2.4 GLIBC_2.4 A
>>  GLIBC_2.4 _Exit F
>>  GLIBC_2.4 _IO_2_1_stderr_ D 0x98
>> diff --git a/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist b/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
>> index 9e016bd..8b1f80c 100644
>> --- a/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
>> +++ b/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
>> @@ -1976,6 +1976,11 @@ GLIBC_2.25 getrandom F
>>  GLIBC_2.25 strfromd F
>>  GLIBC_2.25 strfromf F
>>  GLIBC_2.25 strfroml F
>> +GLIBC_2.26 GLIBC_2.26 A
>> +GLIBC_2.26 preadv2 F
>> +GLIBC_2.26 preadv64v2 F
>> +GLIBC_2.26 pwritev2 F
>> +GLIBC_2.26 pwritev64v2 F
>>  GLIBC_2.3 GLIBC_2.3 A
>>  GLIBC_2.3 __ctype_b_loc F
>>  GLIBC_2.3 __ctype_tolower_loc F
>> diff --git a/sysdeps/unix/sysv/linux/microblaze/libc.abilist b/sysdeps/unix/sysv/linux/microblaze/libc.abilist
>> index 1a455be..d4db9a8 100644
>> --- a/sysdeps/unix/sysv/linux/microblaze/libc.abilist
>> +++ b/sysdeps/unix/sysv/linux/microblaze/libc.abilist
>> @@ -2097,3 +2097,8 @@ GLIBC_2.25 getrandom F
>>  GLIBC_2.25 strfromd F
>>  GLIBC_2.25 strfromf F
>>  GLIBC_2.25 strfroml F
>> +GLIBC_2.26 GLIBC_2.26 A
>> +GLIBC_2.26 preadv2 F
>> +GLIBC_2.26 preadv64v2 F
>> +GLIBC_2.26 pwritev2 F
>> +GLIBC_2.26 pwritev64v2 F
>> diff --git a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
>> index 8eb5e66..f430bdb 100644
>> --- a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
>> +++ b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
>> @@ -1951,6 +1951,11 @@ GLIBC_2.25 getrandom F
>>  GLIBC_2.25 strfromd F
>>  GLIBC_2.25 strfromf F
>>  GLIBC_2.25 strfroml F
>> +GLIBC_2.26 GLIBC_2.26 A
>> +GLIBC_2.26 preadv2 F
>> +GLIBC_2.26 preadv64v2 F
>> +GLIBC_2.26 pwritev2 F
>> +GLIBC_2.26 pwritev64v2 F
>>  GLIBC_2.3 GLIBC_2.3 A
>>  GLIBC_2.3 __ctype_b_loc F
>>  GLIBC_2.3 __ctype_tolower_loc F
>> diff --git a/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
>> index 416d9ac..a4dca19 100644
>> --- a/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
>> +++ b/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
>> @@ -1949,6 +1949,11 @@ GLIBC_2.25 getrandom F
>>  GLIBC_2.25 strfromd F
>>  GLIBC_2.25 strfromf F
>>  GLIBC_2.25 strfroml F
>> +GLIBC_2.26 GLIBC_2.26 A
>> +GLIBC_2.26 preadv2 F
>> +GLIBC_2.26 preadv64v2 F
>> +GLIBC_2.26 pwritev2 F
>> +GLIBC_2.26 pwritev64v2 F
>>  GLIBC_2.3 GLIBC_2.3 A
>>  GLIBC_2.3 __ctype_b_loc F
>>  GLIBC_2.3 __ctype_tolower_loc F
>> diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
>> index f4949e5..0814fa8 100644
>> --- a/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
>> +++ b/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
>> @@ -1947,6 +1947,11 @@ GLIBC_2.25 getrandom F
>>  GLIBC_2.25 strfromd F
>>  GLIBC_2.25 strfromf F
>>  GLIBC_2.25 strfroml F
>> +GLIBC_2.26 GLIBC_2.26 A
>> +GLIBC_2.26 preadv2 F
>> +GLIBC_2.26 preadv64v2 F
>> +GLIBC_2.26 pwritev2 F
>> +GLIBC_2.26 pwritev64v2 F
>>  GLIBC_2.3 GLIBC_2.3 A
>>  GLIBC_2.3 __ctype_b_loc F
>>  GLIBC_2.3 __ctype_tolower_loc F
>> diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
>> index c7375ae..a0bdeff 100644
>> --- a/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
>> +++ b/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
>> @@ -1942,6 +1942,11 @@ GLIBC_2.25 getrandom F
>>  GLIBC_2.25 strfromd F
>>  GLIBC_2.25 strfromf F
>>  GLIBC_2.25 strfroml F
>> +GLIBC_2.26 GLIBC_2.26 A
>> +GLIBC_2.26 preadv2 F
>> +GLIBC_2.26 preadv64v2 F
>> +GLIBC_2.26 pwritev2 F
>> +GLIBC_2.26 pwritev64v2 F
>>  GLIBC_2.3 GLIBC_2.3 A
>>  GLIBC_2.3 __ctype_b_loc F
>>  GLIBC_2.3 __ctype_tolower_loc F
>> diff --git a/sysdeps/unix/sysv/linux/nios2/libc.abilist b/sysdeps/unix/sysv/linux/nios2/libc.abilist
>> index 724a0e3..b201290 100644
>> --- a/sysdeps/unix/sysv/linux/nios2/libc.abilist
>> +++ b/sysdeps/unix/sysv/linux/nios2/libc.abilist
>> @@ -2138,3 +2138,8 @@ GLIBC_2.25 getrandom F
>>  GLIBC_2.25 strfromd F
>>  GLIBC_2.25 strfromf F
>>  GLIBC_2.25 strfroml F
>> +GLIBC_2.26 GLIBC_2.26 A
>> +GLIBC_2.26 preadv2 F
>> +GLIBC_2.26 preadv64v2 F
>> +GLIBC_2.26 pwritev2 F
>> +GLIBC_2.26 pwritev64v2 F
>> diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
>> index 2dc32b6..6e7ff24 100644
>> --- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
>> +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
>> @@ -1980,6 +1980,11 @@ GLIBC_2.25 getrandom F
>>  GLIBC_2.25 strfromd F
>>  GLIBC_2.25 strfromf F
>>  GLIBC_2.25 strfroml F
>> +GLIBC_2.26 GLIBC_2.26 A
>> +GLIBC_2.26 preadv2 F
>> +GLIBC_2.26 preadv64v2 F
>> +GLIBC_2.26 pwritev2 F
>> +GLIBC_2.26 pwritev64v2 F
>>  GLIBC_2.3 GLIBC_2.3 A
>>  GLIBC_2.3 __ctype_b_loc F
>>  GLIBC_2.3 __ctype_tolower_loc F
>> diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
>> index 5658109..19c7c7d 100644
>> --- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
>> +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
>> @@ -1985,6 +1985,11 @@ GLIBC_2.25 getrandom F
>>  GLIBC_2.25 strfromd F
>>  GLIBC_2.25 strfromf F
>>  GLIBC_2.25 strfroml F
>> +GLIBC_2.26 GLIBC_2.26 A
>> +GLIBC_2.26 preadv2 F
>> +GLIBC_2.26 preadv64v2 F
>> +GLIBC_2.26 pwritev2 F
>> +GLIBC_2.26 pwritev64v2 F
>>  GLIBC_2.3 GLIBC_2.3 A
>>  GLIBC_2.3 __ctype_b_loc F
>>  GLIBC_2.3 __ctype_tolower_loc F
>> diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist
>> index c761221..e94ce38 100644
>> --- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist
>> +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist
>> @@ -2185,3 +2185,8 @@ GLIBC_2.25 getrandom F
>>  GLIBC_2.25 strfromd F
>>  GLIBC_2.25 strfromf F
>>  GLIBC_2.25 strfroml F
>> +GLIBC_2.26 GLIBC_2.26 A
>> +GLIBC_2.26 preadv2 F
>> +GLIBC_2.26 preadv64v2 F
>> +GLIBC_2.26 pwritev2 F
>> +GLIBC_2.26 pwritev64v2 F
>> diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist
>> index 265c769..f3daa33 100644
>> --- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist
>> +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist
>> @@ -99,6 +99,11 @@ GLIBC_2.25 getrandom F
>>  GLIBC_2.25 strfromd F
>>  GLIBC_2.25 strfromf F
>>  GLIBC_2.25 strfroml F
>> +GLIBC_2.26 GLIBC_2.26 A
>> +GLIBC_2.26 preadv2 F
>> +GLIBC_2.26 preadv64v2 F
>> +GLIBC_2.26 pwritev2 F
>> +GLIBC_2.26 pwritev64v2 F
>>  GLIBC_2.3 GLIBC_2.3 A
>>  GLIBC_2.3 _Exit F
>>  GLIBC_2.3 _IO_2_1_stderr_ D 0xe0
>> diff --git a/sysdeps/unix/sysv/linux/preadv.c b/sysdeps/unix/sysv/linux/preadv.c
>> index 7d971cc..ecabc8c 100644
>> --- a/sysdeps/unix/sysv/linux/preadv.c
>> +++ b/sysdeps/unix/sysv/linux/preadv.c
>> @@ -50,4 +50,6 @@ preadv (int fd, const struct iovec *vector, int count, off_t offset)
>>  #  define OFF_T off_t
>>  #  include <sysdeps/posix/preadv_common.c>
>>  # endif /* __ASSUME_PREADV  */
>> +
>> +libc_hidden_def (preadv)
>>  #endif
>> diff --git a/sysdeps/unix/sysv/linux/preadv2.c b/sysdeps/unix/sysv/linux/preadv2.c
>> new file mode 100644
>> index 0000000..11fe85e
>> --- /dev/null
>> +++ b/sysdeps/unix/sysv/linux/preadv2.c
>> @@ -0,0 +1,55 @@
>> +/* Linux implementation of preadv2.
>> +   Copyright (C) 2017 Free Software Foundation, Inc.
>> +   This file is part of the GNU C Library.
>> +
>> +   The GNU C Library is free software; you can redistribute it and/or
>> +   modify it under the terms of the GNU Lesser General Public
>> +   License as published by the Free Software Foundation; either
>> +   version 2.1 of the License, or (at your option) any later version.
>> +
>> +   The GNU C Library is distributed in the hope that it will be useful,
>> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
>> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>> +   Lesser General Public License for more details.
>> +
>> +   You should have received a copy of the GNU Lesser General Public
>> +   License along with the GNU C Library; if not, see
>> +   <http://www.gnu.org/licenses/>.  */
>> +
>> +#include <sys/uio.h>
>> +#include <sysdep-cancel.h>
>> +
>> +#ifndef __OFF_T_MATCHES_OFF64_T
>> +
>> +# if !defined (__NR_preadv2) && defined (__NR_pread64v2)
>> +#  define __NR_preadv2 __NR_pread64v2
>> +# endif
>> +
>> +ssize_t
>> +preadv2 (int fd, const struct iovec *vector, int count, off_t offset,
>> +	 int flags)
>> +{
>> +# ifdef __NR_preadv2
>> +  ssize_t result = SYSCALL_CANCEL (preadv2, fd, vector, count,
>> +				   LO_HI_LONG (offset), flags);
>> +  if (result >= 0 || errno != ENOSYS)
>> +    return result;
>> +# endif
>> +  /* Trying to emulate the preadv2 syscall flags is troublesome:
>> +
>> +     * We can not temporary change the file state of the O_DSYNC and O_SYNC
>> +       flags to emulate RWF_{D}SYNC (attempts to change the state of using
>> +       fcntl are silently ignored).
>> +
>> +     * IOCB_HIPRI requires the file opened in O_DIRECT and uses an internal
>> +       semantic not provided by any other flag (O_NONBLOCK for instance).  */
>> +
>> +  if (flags != 0)
>> +    {
>> +      __set_errno (EOPNOTSUPP);
>> +      return -1;
>> +    }
>> +  return preadv (fd, vector, count, offset);
>> +}
>> +
>> +#endif
>> diff --git a/sysdeps/unix/sysv/linux/preadv64.c b/sysdeps/unix/sysv/linux/preadv64.c
>> index 66daa74..c96b214 100644
>> --- a/sysdeps/unix/sysv/linux/preadv64.c
>> +++ b/sysdeps/unix/sysv/linux/preadv64.c
>> @@ -48,7 +48,9 @@ preadv64 (int fd, const struct iovec *vector, int count, off64_t offset)
>>  # define OFF_T off64_t
>>  # include <sysdeps/posix/preadv_common.c>
>>  #endif
>> +libc_hidden_def (preadv64)
>>  
>>  #ifdef __OFF_T_MATCHES_OFF64_T
>>  strong_alias (preadv64, preadv)
>> +libc_hidden_def (preadv)
>>  #endif
>> diff --git a/sysdeps/unix/sysv/linux/preadv64v2.c b/sysdeps/unix/sysv/linux/preadv64v2.c
>> new file mode 100644
>> index 0000000..9d7f8c9
>> --- /dev/null
>> +++ b/sysdeps/unix/sysv/linux/preadv64v2.c
>> @@ -0,0 +1,55 @@
>> +/* Linux implementation of preadv2 (LFS version).
>> +   Copyright (C) 2017 Free Software Foundation, Inc.
>> +   This file is part of the GNU C Library.
>> +
>> +   The GNU C Library is free software; you can redistribute it and/or
>> +   modify it under the terms of the GNU Lesser General Public
>> +   License as published by the Free Software Foundation; either
>> +   version 2.1 of the License, or (at your option) any later version.
>> +
>> +   The GNU C Library is distributed in the hope that it will be useful,
>> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
>> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>> +   Lesser General Public License for more details.
>> +
>> +   You should have received a copy of the GNU Lesser General Public
>> +   License along with the GNU C Library; if not, see
>> +   <http://www.gnu.org/licenses/>.  */
>> +
>> +#include <sys/uio.h>
>> +#include <sysdep-cancel.h>
>> +
>> +#if !defined(__NR_preadv64v2) && defined(__NR_preadv2)
>> +# define __NR_preadv64v2 __NR_preadv2
>> +#endif
>> +
>> +ssize_t
>> +preadv64v2 (int fd, const struct iovec *vector, int count, off64_t offset,
>> +	    int flags)
>> +{
>> +#ifdef __NR_preadv64v2
>> +  ssize_t result = SYSCALL_CANCEL (preadv64v2, fd, vector, count,
>> +				   LO_HI_LONG (offset), flags);
>> +  if (result >= 0 || errno != ENOSYS)
>> +    return result;
>> +#endif
>> +  /* Trying to emulate the preadv2 syscall flags is troublesome:
>> +
>> +     * We can not temporary change the file state of the O_DSYNC and O_SYNC
>> +       flags to emulate RWF_{D}SYNC (attempts to change the state of using
>> +       fcntl are silently ignored).
>> +
>> +     * IOCB_HIPRI requires the file opened in O_DIRECT and uses an internal
>> +       semantic not provided by any other flag (O_NONBLOCK for instance).  */
>> +
>> +  if (flags != 0)
>> +    {
>> +      __set_errno (EOPNOTSUPP);
>> +      return -1;
>> +    }
>> +  return preadv64 (fd, vector, count, offset);
>> +}
>> +
>> +#ifdef __OFF_T_MATCHES_OFF64_T
>> +strong_alias (preadv64v2, preadv2)
>> +#endif
>> diff --git a/sysdeps/unix/sysv/linux/pwrite64.c b/sysdeps/unix/sysv/linux/pwrite64.c
>> index 57e5d20..71959c0 100644
>> --- a/sysdeps/unix/sysv/linux/pwrite64.c
>> +++ b/sysdeps/unix/sysv/linux/pwrite64.c
>> @@ -28,6 +28,7 @@ __libc_pwrite64 (int fd, const void *buf, size_t count, off64_t offset)
>>  {
>>    return SYSCALL_CANCEL (pwrite64, fd, buf, count, SYSCALL_LL64_PRW (offset));
>>  }
>> +
>>  weak_alias (__libc_pwrite64, __pwrite64)
>>  libc_hidden_weak (__pwrite64)
>>  weak_alias (__libc_pwrite64, pwrite64)
>> diff --git a/sysdeps/unix/sysv/linux/pwritev.c b/sysdeps/unix/sysv/linux/pwritev.c
>> index ce02996..7545cb3 100644
>> --- a/sysdeps/unix/sysv/linux/pwritev.c
>> +++ b/sysdeps/unix/sysv/linux/pwritev.c
>> @@ -50,4 +50,6 @@ pwritev (int fd, const struct iovec *vector, int count, off_t offset)
>>  #  define OFF_T off_t
>>  #  include <sysdeps/posix/pwritev_common.c>
>>  # endif /* __ASSUME_PREADV  */
>> +
>> +libc_hidden_def (pwritev)
>>  #endif
>> diff --git a/sysdeps/unix/sysv/linux/pwritev2.c b/sysdeps/unix/sysv/linux/pwritev2.c
>> new file mode 100644
>> index 0000000..72f0471
>> --- /dev/null
>> +++ b/sysdeps/unix/sysv/linux/pwritev2.c
>> @@ -0,0 +1,51 @@
>> +/* Linux implementation of pwritev2.
>> +   Copyright (C) 2017 Free Software Foundation, Inc.
>> +   This file is part of the GNU C Library.
>> +
>> +   The GNU C Library is free software; you can redistribute it and/or
>> +   modify it under the terms of the GNU Lesser General Public
>> +   License as published by the Free Software Foundation; either
>> +   version 2.1 of the License, or (at your option) any later version.
>> +
>> +   The GNU C Library is distributed in the hope that it will be useful,
>> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
>> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>> +   Lesser General Public License for more details.
>> +
>> +   You should have received a copy of the GNU Lesser General Public
>> +   License along with the GNU C Library; if not, see
>> +   <http://www.gnu.org/licenses/>.  */
>> +
>> +#include <sys/uio.h>
>> +#include <sysdep-cancel.h>
>> +
>> +#ifndef __OFF_T_MATCHES_OFF64_T
>> +
>> +ssize_t
>> +pwritev2 (int fd, const struct iovec *vector, int count, off_t offset,
>> +	  int flags)
>> +{
>> +# ifdef __NR_pwritev2
>> +  ssize_t result = SYSCALL_CANCEL (pwritev2, fd, vector, count,
>> +				   LO_HI_LONG (offset), flags);
>> +  if (result >= 0 || errno != ENOSYS)
>> +    return result;
>> +# endif
>> +  /* Trying to emulate the pwritev2 syscall flags is troublesome:
>> +
>> +     * We can not temporary change the file state of the O_DSYNC and O_SYNC
>> +       flags to emulate RWF_{D}SYNC (attempts to change the state of using
>> +       fcntl are silently ignored).
>> +
>> +     * IOCB_HIPRI requires the file opened in O_DIRECT and uses an internal
>> +       semantic not provided by any other flag (O_NONBLOCK for instance).  */
>> +
>> +  if (flags != 0)
>> +    {
>> +      __set_errno (EOPNOTSUPP);
>> +      return -1;
>> +    }
>> +  return pwritev (fd, vector, count, offset);
>> +}
>> +
>> +#endif
>> diff --git a/sysdeps/unix/sysv/linux/pwritev64.c b/sysdeps/unix/sysv/linux/pwritev64.c
>> index 45fb90b..9dc4e55 100644
>> --- a/sysdeps/unix/sysv/linux/pwritev64.c
>> +++ b/sysdeps/unix/sysv/linux/pwritev64.c
>> @@ -48,7 +48,9 @@ pwritev64 (int fd, const struct iovec *vector, int count, off64_t offset)
>>  # define OFF_T off64_t
>>  # include <sysdeps/posix/pwritev_common.c>
>>  #endif
>> +libc_hidden_def (pwritev64)
>>  
>>  #ifdef __OFF_T_MATCHES_OFF64_T
>>  strong_alias (pwritev64, pwritev)
>> +libc_hidden_def (pwritev)
>>  #endif
>> diff --git a/sysdeps/unix/sysv/linux/pwritev64v2.c b/sysdeps/unix/sysv/linux/pwritev64v2.c
>> new file mode 100644
>> index 0000000..def9a0b
>> --- /dev/null
>> +++ b/sysdeps/unix/sysv/linux/pwritev64v2.c
>> @@ -0,0 +1,55 @@
>> +/* Linux implementation of pwritev2 (LFS version).
>> +   Copyright (C) 2017 Free Software Foundation, Inc.
>> +   This file is part of the GNU C Library.
>> +
>> +   The GNU C Library is free software; you can redistribute it and/or
>> +   modify it under the terms of the GNU Lesser General Public
>> +   License as published by the Free Software Foundation; either
>> +   version 2.1 of the License, or (at your option) any later version.
>> +
>> +   The GNU C Library is distributed in the hope that it will be useful,
>> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
>> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>> +   Lesser General Public License for more details.
>> +
>> +   You should have received a copy of the GNU Lesser General Public
>> +   License along with the GNU C Library; if not, see
>> +   <http://www.gnu.org/licenses/>.  */
>> +
>> +#include <sys/uio.h>
>> +#include <sysdep-cancel.h>
>> +
>> +#if !defined(__NR_pwritev64v2) && defined(__NR_pwritev2)
>> +# define __NR_pwritev64v2 __NR_pwritev2
>> +#endif
>> +
>> +ssize_t
>> +pwritev64v2 (int fd, const struct iovec *vector, int count, off64_t offset,
>> +	     int flags)
>> +{
>> +#ifdef __NR_pwritev64v2
>> +  ssize_t result = SYSCALL_CANCEL (pwritev64v2, fd, vector, count,
>> +				   LO_HI_LONG (offset), flags);
>> +  if (result >= 0 || errno != ENOSYS)
>> +    return result;
>> +#endif
>> +  /* Trying to emulate the pwritev2 syscall flags is troublesome:
>> +
>> +     * We can not temporary change the file state of the O_DSYNC and O_SYNC
>> +       flags to emulate RWF_{D}SYNC (attempts to change the state of using
>> +       fcntl are silently ignored).
>> +
>> +     * IOCB_HIPRI requires the file opened in O_DIRECT and uses an internal
>> +       semantic not provided by any other flag (O_NONBLOCK for instance).  */
>> +
>> +  if (flags != 0)
>> +    {
>> +      __set_errno (EOPNOTSUPP);
>> +      return -1;
>> +    }
>> +  return pwritev64 (fd, vector, count, offset);
>> +}
>> +
>> +#ifdef __OFF_T_MATCHES_OFF64_T
>> +strong_alias (pwritev64v2, pwritev2)
>> +#endif
>> diff --git a/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist b/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
>> index ed1b6bf..eb9e72f 100644
>> --- a/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
>> +++ b/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
>> @@ -1980,6 +1980,11 @@ GLIBC_2.25 getrandom F
>>  GLIBC_2.25 strfromd F
>>  GLIBC_2.25 strfromf F
>>  GLIBC_2.25 strfroml F
>> +GLIBC_2.26 GLIBC_2.26 A
>> +GLIBC_2.26 preadv2 F
>> +GLIBC_2.26 preadv64v2 F
>> +GLIBC_2.26 pwritev2 F
>> +GLIBC_2.26 pwritev64v2 F
>>  GLIBC_2.3 GLIBC_2.3 A
>>  GLIBC_2.3 __ctype_b_loc F
>>  GLIBC_2.3 __ctype_tolower_loc F
>> diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist b/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
>> index 2e75d29..1402959 100644
>> --- a/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
>> +++ b/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
>> @@ -1881,6 +1881,11 @@ GLIBC_2.25 getrandom F
>>  GLIBC_2.25 strfromd F
>>  GLIBC_2.25 strfromf F
>>  GLIBC_2.25 strfroml F
>> +GLIBC_2.26 GLIBC_2.26 A
>> +GLIBC_2.26 preadv2 F
>> +GLIBC_2.26 preadv64v2 F
>> +GLIBC_2.26 pwritev2 F
>> +GLIBC_2.26 pwritev64v2 F
>>  GLIBC_2.3 GLIBC_2.3 A
>>  GLIBC_2.3 __ctype_b_loc F
>>  GLIBC_2.3 __ctype_tolower_loc F
>> diff --git a/sysdeps/unix/sysv/linux/sh/libc.abilist b/sysdeps/unix/sysv/linux/sh/libc.abilist
>> index bd74c0c..e9eefcb 100644
>> --- a/sysdeps/unix/sysv/linux/sh/libc.abilist
>> +++ b/sysdeps/unix/sysv/linux/sh/libc.abilist
>> @@ -1866,6 +1866,11 @@ GLIBC_2.25 getrandom F
>>  GLIBC_2.25 strfromd F
>>  GLIBC_2.25 strfromf F
>>  GLIBC_2.25 strfroml F
>> +GLIBC_2.26 GLIBC_2.26 A
>> +GLIBC_2.26 preadv2 F
>> +GLIBC_2.26 preadv64v2 F
>> +GLIBC_2.26 pwritev2 F
>> +GLIBC_2.26 pwritev64v2 F
>>  GLIBC_2.3 GLIBC_2.3 A
>>  GLIBC_2.3 __ctype_b_loc F
>>  GLIBC_2.3 __ctype_tolower_loc F
>> diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist b/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
>> index 5584838..967699e 100644
>> --- a/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
>> +++ b/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
>> @@ -1972,6 +1972,11 @@ GLIBC_2.25 getrandom F
>>  GLIBC_2.25 strfromd F
>>  GLIBC_2.25 strfromf F
>>  GLIBC_2.25 strfroml F
>> +GLIBC_2.26 GLIBC_2.26 A
>> +GLIBC_2.26 preadv2 F
>> +GLIBC_2.26 preadv64v2 F
>> +GLIBC_2.26 pwritev2 F
>> +GLIBC_2.26 pwritev64v2 F
>>  GLIBC_2.3 GLIBC_2.3 A
>>  GLIBC_2.3 __ctype_b_loc F
>>  GLIBC_2.3 __ctype_tolower_loc F
>> diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist b/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
>> index efedbe2..9dd938a 100644
>> --- a/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
>> +++ b/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
>> @@ -1910,6 +1910,11 @@ GLIBC_2.25 getrandom F
>>  GLIBC_2.25 strfromd F
>>  GLIBC_2.25 strfromf F
>>  GLIBC_2.25 strfroml F
>> +GLIBC_2.26 GLIBC_2.26 A
>> +GLIBC_2.26 preadv2 F
>> +GLIBC_2.26 preadv64v2 F
>> +GLIBC_2.26 pwritev2 F
>> +GLIBC_2.26 pwritev64v2 F
>>  GLIBC_2.3 GLIBC_2.3 A
>>  GLIBC_2.3 __ctype_b_loc F
>>  GLIBC_2.3 __ctype_tolower_loc F
>> diff --git a/sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist b/sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist
>> index ffd988a..68c9887 100644
>> --- a/sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist
>> +++ b/sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist
>> @@ -2104,3 +2104,8 @@ GLIBC_2.25 getrandom F
>>  GLIBC_2.25 strfromd F
>>  GLIBC_2.25 strfromf F
>>  GLIBC_2.25 strfroml F
>> +GLIBC_2.26 GLIBC_2.26 A
>> +GLIBC_2.26 preadv2 F
>> +GLIBC_2.26 preadv64v2 F
>> +GLIBC_2.26 pwritev2 F
>> +GLIBC_2.26 pwritev64v2 F
>> diff --git a/sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist b/sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist
>> index f0c13ce..97aa0f7 100644
>> --- a/sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist
>> +++ b/sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist
>> @@ -2104,3 +2104,8 @@ GLIBC_2.25 getrandom F
>>  GLIBC_2.25 strfromd F
>>  GLIBC_2.25 strfromf F
>>  GLIBC_2.25 strfroml F
>> +GLIBC_2.26 GLIBC_2.26 A
>> +GLIBC_2.26 preadv2 F
>> +GLIBC_2.26 preadv64v2 F
>> +GLIBC_2.26 pwritev2 F
>> +GLIBC_2.26 pwritev64v2 F
>> diff --git a/sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist b/sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist
>> index ffd988a..68c9887 100644
>> --- a/sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist
>> +++ b/sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist
>> @@ -2104,3 +2104,8 @@ GLIBC_2.25 getrandom F
>>  GLIBC_2.25 strfromd F
>>  GLIBC_2.25 strfromf F
>>  GLIBC_2.25 strfroml F
>> +GLIBC_2.26 GLIBC_2.26 A
>> +GLIBC_2.26 preadv2 F
>> +GLIBC_2.26 preadv64v2 F
>> +GLIBC_2.26 pwritev2 F
>> +GLIBC_2.26 pwritev64v2 F
>> diff --git a/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist b/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
>> index f57004c..2032659 100644
>> --- a/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
>> +++ b/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
>> @@ -1861,6 +1861,11 @@ GLIBC_2.25 getrandom F
>>  GLIBC_2.25 strfromd F
>>  GLIBC_2.25 strfromf F
>>  GLIBC_2.25 strfroml F
>> +GLIBC_2.26 GLIBC_2.26 A
>> +GLIBC_2.26 preadv2 F
>> +GLIBC_2.26 preadv64v2 F
>> +GLIBC_2.26 pwritev2 F
>> +GLIBC_2.26 pwritev64v2 F
>>  GLIBC_2.3 GLIBC_2.3 A
>>  GLIBC_2.3 __ctype_b_loc F
>>  GLIBC_2.3 __ctype_tolower_loc F
>> diff --git a/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist b/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
>> index 05629e1..11a278c 100644
>> --- a/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
>> +++ b/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
>> @@ -2104,3 +2104,8 @@ GLIBC_2.25 getrandom F
>>  GLIBC_2.25 strfromd F
>>  GLIBC_2.25 strfromf F
>>  GLIBC_2.25 strfroml F
>> +GLIBC_2.26 GLIBC_2.26 A
>> +GLIBC_2.26 preadv2 F
>> +GLIBC_2.26 preadv64v2 F
>> +GLIBC_2.26 pwritev2 F
>> +GLIBC_2.26 pwritev64v2 F
>>
Adhemerval Zanella May 31, 2017, 6:51 p.m. UTC | #3
I will commit this shortly.

On 30/05/2017 11:18, Adhemerval Zanella wrote:
> Ping x2.  Any impeding issue about this patch? Otherwise I would like to push it.
> 
> On 11/05/2017 16:01, Adhemerval Zanella wrote:
>> Ping.
>>
>> On 04/05/2017 09:43, Adhemerval Zanella wrote:
>>> Change from previous version:
>>>
>>>    * Add unsupported flag check for Linux implementation.
>>>
>>>    * Unsupported/invalid flags now return EOPNOTSUPP instead of
>>>      EINVAL.
>>>
>>>    * Add comment about preadv2 and pwritev2 support on kernel-features.h.
>>>
>>>    * Add NEWS entry.
>>>
>>>    * Fix typo in documentation.
>>>         
>>> --
>>>
>>> This patch adds support of preadv2 and pwritev2 which are similar to
>>> preadv/pwritev but adds an extra flag argument.  As for preadv/pwritev
>>> both interfaces are added a non-standard standard GNU API.
>>>
>>> On default 'posix' implementation trying to emulate the Linux supported
>>> flags is troublesome:
>>>
>>>    * We can not temporary change the file state of the O_DSYNC and O_SYNC
>>>      flags to emulate RWF_{D}SYNC (attempts to change the state of using
>>>      fcntl are silently ignored).
>>>
>>>    * IOCB_HIPRI requires the file opened in O_DIRECT and uses an internal
>>>      semantic not provided by any other flag (O_NONBLOCK for instance).
>>>
>>> So default sysdeps/posix implementations fails with EINVAL for any non
>>> supported flag (which are none currently) calls generic preadv/pwritev.
>>> Basically, it supports only preadv2 called as preadv (with flags sets
>>> to 0).
>>>
>>> The Linux one uses the preadv2/pwritev2 syscall if defined, otherwise it
>>> call preadv/writev.  Instead of using the previous __ASSUME_* to
>>> unconditionally issue the syscall (and avoid building the fallback routine),
>>> it call pread/write if the preadv2/pwritev2 syscalls fails.  The idea
>>> is just avoid adding another __ASSUME_* and checking each architecture
>>> on every kernel bump and simplify code conditionals.
>>>
>>> Checked on x86_64-linux-gnu and on i686-linux-gnu and a check with
>>> run-built-tests=no on aarch64-linux-gnu, alpha-linux-gnu, arm-linux-gnueabihf,
>>> ia64-linux-gnu, m68k-linux-gnu, microblaze-linux-gnu, mips{64,64n32}-linux-gnu,
>>> nios2-linux-gnu, powerpc{64,64le}-linux-gnu, s390{x}-linux-gnu,
>>> sparc{64,v9}-linux-gnu, tile{gx,pro}-linux-gnu, and sh4-linux-gnu (all using
>>> gcc 6.3).
>>>
>>> 	* NEWS: Add note about pwritev2 and preadv2 inclusion.
>>> 	* misc/Makefile (routines): Add preadv2, preadv64v2, pwritev2, and
>>> 	pwritev64v2.
>>> 	(tests): Add tst-preadvwritev2 and tst-preadvwritev64v2.
>>> 	* misc/Versions (GLIBC_2.26): Add preadv2, preadv64v2, pwritev2, and
>>> 	pwritev64v2.
>>> 	* misc/preadv2.c: New file.
>>> 	* misc/preadv64v2.c: Likewise.
>>> 	* misc/pwritev2.c: Likewise.
>>> 	* misc/pwritev64v2.c: Likewise.
>>> 	* misc/tst-preadvwritev2.c: Likewise.
>>> 	* misc/tst-preadvwritev64v2.c: Likewise.
>>> 	* manual/llio.texi: Add preadv2 and pwritev2 documentation.
>>> 	* misc/sys/uio.h [__USE_GNU && !__USE_FILE_OFFSET64] (preadv2): New
>>> 	prototype.
>>> 	[__USE_GNU && !__USE_FILE_OFFSET64] (pwritev2):	Likewise.
>>> 	[__USE_GNU && __USE_FILE_OFFSET64] (preadv64v2): Likewise.
>>> 	[__USE_GNU && __USE_FILE_OFFSET64] (pwritev64v2): Likewise.
>>> 	* misc/tst-preadvwritev-common.c (PREADV): Define if not defined.
>>> 	(PWRITEV): Likewise.
>>> 	(do_test_with_offset): Use PREADV and PWRITEV macros and check for
>>> 	ENOSYS.
>>> 	* nptl/tst-cancel4.c (tf_pwritev2): New test.
>>> 	(tf_preadv2): Likewise.
>>> 	(tf_fsync): Add tf_pwritev2 and tf_preadv2.
>>> 	* sysdeps/posix/preadv2.c: Likewise.
>>> 	* sysdeps/posix/preadv64v2.c: Likewise.
>>> 	* sysdeps/posix/pwritev2.c: Likewise.
>>> 	* sysdeps/posix/pwritev64v2.c: Likewise.
>>> 	* sysdeps/unix/sysv/linux/kernel-features.h: Add comment for syscall
>>> 	support in kernel.
>>> 	* sysdeps/unix/sysv/linux/preadv2.c: Likewise.
>>> 	* sysdeps/unix/sysv/linux/preadv64v2.c: Likewise.
>>> 	* sysdeps/unix/sysv/linux/pwritev2.c: Likewise.
>>> 	* sysdeps/unix/sysv/linux/pwritev64v2.c: Likewise.
>>> 	* sysdeps/unix/sysv/linux/preadv.c (preadv): Add libc_hidden_def.
>>> 	* sysdeps/unix/sysv/linux/preadv64.c (preadv64): Likewise.
>>> 	* sysdeps/unix/sysv/linux/pwritev.c (pwritev): Likewise.
>>> 	* sysdeps/unix/sysv/linux/pwritev64.c (pwritev64): Likewise.
>>> 	* sysdeps/unix/sysv/linux/bits/uio.h: Add supported preadv2/pwritev2
>>> 	support flags on Linux.
>>> 	* sysdeps/unix/sysv/linux/aarch64/libc.abilist (GLIBC_2.26): Add
>>> 	preadv2, preadv64v2, pwritev2, pwritev64v2.
>>> 	* sysdeps/unix/sysv/linux/alpha/libc.abilist (GLIBC_2.26): Likewise.
>>> 	* sysdeps/unix/sysv/linux/arm/libc.abilist (GLIBC_2.26): Likewise.
>>> 	* sysdeps/unix/sysv/linux/hppa/libc.abilist (GLIBC_2.26): Likewise.
>>> 	* sysdeps/unix/sysv/linux/i386/libc.abilist (GLIBC_2.26): Likewise.
>>> 	* sysdeps/unix/sysv/linux/ia64/libc.abilist (GLIBC_2.26): Likewise.
>>> 	* sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist (GLIBC_2.26):
>>> 	Likewise.
>>> 	* sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist (GLIBC_2.26):
>>> 	Likewise.
>>> 	* sysdeps/unix/sysv/linux/microblaze/libc.abilist (GLIBC_2.26):
>>> 	Likewise.
>>> 	* sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist (GLIBC_2.26):
>>> 	Likewise.
>>> 	* sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist (GLIBC_2.26):
>>> 	Likewise.
>>> 	* sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist (GLIBC_2.26):
>>> 	Likewise.
>>> 	* sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist (GLIBC_2.26):
>>> 	Likewise.
>>> 	* sysdeps/unix/sysv/linux/nios2/libc.abilist (GLIBC_2.26): Likewise.
>>> 	* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
>>> 	(GLIBC_2.26): Likewise.
>>> 	* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
>>> 	(GLIBC_2.26): Likewise.
>>> 	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist (GLIBC_2.26):
>>> 	Likewise.
>>> 	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist
>>> 	(GLIBC_2.26): Likewise.
>>> 	* sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist (GLIBC_2.26):
>>> 	Likewise.
>>> 	* sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist (GLIBC_2.26):
>>> 	Likewise.
>>> 	* sysdeps/unix/sysv/linux/sh/libc.abilist (GLIBC_2.26): Likewise.
>>> 	* sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist (GLIBC_2.26):
>>> 	Likewise.
>>> 	* sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist (GLIBC_2.26):
>>> 	Likewise.
>>> 	* sysdeps/sysv/linux/tile/tilegx/tilegx32/libc.abilist (GLIBC_2.26):
>>> 	Likewise.
>>> 	* sysdeps/sysv/linux/tile/tilegx/tilegx64/libc.abilist (GLIBC_2.26):
>>> 	Likewise.
>>> 	* sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist (GLIBC_2.26):
>>> 	Likewise.
>>> 	* sysdeps/unix/sysv/linux/x86_64/64/libc.abilist (GLIBC_2.26):
>>> 	Likewise.
>>> 	* sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist (GLIBC_2.26):
>>> 	Likewise.
>>> ---
>>>  ChangeLog                                          |  91 +++++++++++++++++
>>>  NEWS                                               |   7 ++
>>>  include/sys/uio.h                                  |   6 ++
>>>  manual/llio.texi                                   | 109 +++++++++++++++++++++
>>>  misc/Makefile                                      |   5 +-
>>>  misc/Versions                                      |   3 +
>>>  misc/preadv2.c                                     |  30 ++++++
>>>  misc/preadv64v2.c                                  |  30 ++++++
>>>  misc/pwritev2.c                                    |  30 ++++++
>>>  misc/pwritev64v2.c                                 |  30 ++++++
>>>  misc/sys/uio.h                                     |  41 ++++++++
>>>  misc/tst-preadvwritev-common.c                     |  19 +++-
>>>  misc/tst-preadvwritev2.c                           |  31 ++++++
>>>  misc/tst-preadvwritev64v2.c                        |  33 +++++++
>>>  nptl/tst-cancel4.c                                 |  71 ++++++++++++++
>>>  sysdeps/posix/preadv2.c                            |  38 +++++++
>>>  sysdeps/posix/preadv64v2.c                         |  37 +++++++
>>>  sysdeps/posix/pwritev2.c                           |  38 +++++++
>>>  sysdeps/posix/pwritev64v2.c                        |  38 +++++++
>>>  sysdeps/unix/sysv/linux/aarch64/libc.abilist       |   5 +
>>>  sysdeps/unix/sysv/linux/alpha/libc.abilist         |   5 +
>>>  sysdeps/unix/sysv/linux/arm/libc.abilist           |   5 +
>>>  sysdeps/unix/sysv/linux/bits/uio.h                 |   6 ++
>>>  sysdeps/unix/sysv/linux/hppa/libc.abilist          |   5 +
>>>  sysdeps/unix/sysv/linux/i386/libc.abilist          |   5 +
>>>  sysdeps/unix/sysv/linux/ia64/libc.abilist          |   5 +
>>>  sysdeps/unix/sysv/linux/kernel-features.h          |   5 +
>>>  sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist |   5 +
>>>  sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist   |   5 +
>>>  sysdeps/unix/sysv/linux/microblaze/libc.abilist    |   5 +
>>>  .../unix/sysv/linux/mips/mips32/fpu/libc.abilist   |   5 +
>>>  .../unix/sysv/linux/mips/mips32/nofpu/libc.abilist |   5 +
>>>  .../unix/sysv/linux/mips/mips64/n32/libc.abilist   |   5 +
>>>  .../unix/sysv/linux/mips/mips64/n64/libc.abilist   |   5 +
>>>  sysdeps/unix/sysv/linux/nios2/libc.abilist         |   5 +
>>>  .../sysv/linux/powerpc/powerpc32/fpu/libc.abilist  |   5 +
>>>  .../linux/powerpc/powerpc32/nofpu/libc.abilist     |   5 +
>>>  .../sysv/linux/powerpc/powerpc64/libc-le.abilist   |   5 +
>>>  .../unix/sysv/linux/powerpc/powerpc64/libc.abilist |   5 +
>>>  sysdeps/unix/sysv/linux/preadv.c                   |   2 +
>>>  sysdeps/unix/sysv/linux/preadv2.c                  |  55 +++++++++++
>>>  sysdeps/unix/sysv/linux/preadv64.c                 |   2 +
>>>  sysdeps/unix/sysv/linux/preadv64v2.c               |  55 +++++++++++
>>>  sysdeps/unix/sysv/linux/pwrite64.c                 |   1 +
>>>  sysdeps/unix/sysv/linux/pwritev.c                  |   2 +
>>>  sysdeps/unix/sysv/linux/pwritev2.c                 |  51 ++++++++++
>>>  sysdeps/unix/sysv/linux/pwritev64.c                |   2 +
>>>  sysdeps/unix/sysv/linux/pwritev64v2.c              |  55 +++++++++++
>>>  sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist  |   5 +
>>>  sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist  |   5 +
>>>  sysdeps/unix/sysv/linux/sh/libc.abilist            |   5 +
>>>  sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist |   5 +
>>>  sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist |   5 +
>>>  .../sysv/linux/tile/tilegx/tilegx32/libc.abilist   |   5 +
>>>  .../sysv/linux/tile/tilegx/tilegx64/libc.abilist   |   5 +
>>>  sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist  |   5 +
>>>  sysdeps/unix/sysv/linux/x86_64/64/libc.abilist     |   5 +
>>>  sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist    |   5 +
>>>  58 files changed, 1058 insertions(+), 5 deletions(-)
>>>  create mode 100644 misc/preadv2.c
>>>  create mode 100644 misc/preadv64v2.c
>>>  create mode 100644 misc/pwritev2.c
>>>  create mode 100644 misc/pwritev64v2.c
>>>  create mode 100644 misc/tst-preadvwritev2.c
>>>  create mode 100644 misc/tst-preadvwritev64v2.c
>>>  create mode 100644 sysdeps/posix/preadv2.c
>>>  create mode 100644 sysdeps/posix/preadv64v2.c
>>>  create mode 100644 sysdeps/posix/pwritev2.c
>>>  create mode 100644 sysdeps/posix/pwritev64v2.c
>>>  create mode 100644 sysdeps/unix/sysv/linux/preadv2.c
>>>  create mode 100644 sysdeps/unix/sysv/linux/preadv64v2.c
>>>  create mode 100644 sysdeps/unix/sysv/linux/pwritev2.c
>>>  create mode 100644 sysdeps/unix/sysv/linux/pwritev64v2.c
>>>
>>> diff --git a/NEWS b/NEWS
>>> index 5558ca3..afad4b1 100644
>>> --- a/NEWS
>>> +++ b/NEWS
>>> @@ -57,6 +57,13 @@ Version 2.26
>>>    be added on next major revision of POSIX, so current support is enabled
>>>    with _GNU_SOURCE.
>>>  
>>> +* New preadv2 and pwritev2 are added to libc.  They are Linux extensions to
>>> +  preadv and pwritev with an additional flag argument where it is possible
>>> +  to set high priority or use O_DSYNC or O_SYNC for an specific IO operation.
>>> +  For complete support it requires Linux kernel version 4.6, otherwise a
>>> +  compat implementation will be used (which refuses all flags and routes it
>>> +  to preadv or pwritev).
>>> +
>>>  Security related changes:
>>>  
>>>  * The DNS stub resolver limits the advertised UDP buffer size to 1200 bytes,
>>> diff --git a/include/sys/uio.h b/include/sys/uio.h
>>> index f44ce18..20860bf 100644
>>> --- a/include/sys/uio.h
>>> +++ b/include/sys/uio.h
>>> @@ -7,5 +7,11 @@ extern ssize_t __readv (int __fd, const struct iovec *__iovec,
>>>  			int __count);
>>>  extern ssize_t __writev (int __fd, const struct iovec *__iovec,
>>>  			 int __count);
>>> +
>>> +/* Used for p{read,write}{v64}v2 implementation.  */
>>> +libc_hidden_proto (preadv)
>>> +libc_hidden_proto (preadv64)
>>> +libc_hidden_proto (pwritev)
>>> +libc_hidden_proto (pwritev64)
>>>  #endif
>>>  #endif
>>> diff --git a/manual/llio.texi b/manual/llio.texi
>>> index dae3754..404a966 100644
>>> --- a/manual/llio.texi
>>> +++ b/manual/llio.texi
>>> @@ -756,6 +756,115 @@ When the source file is compiled using @code{_FILE_OFFSET_BITS == 64} on a
>>>  @code{pwritev} and so transparently replaces the 32 bit interface.
>>>  @end deftypefun
>>>  
>>> +@comment sys/uio.h
>>> +@comment GNU
>>> +@deftypefun ssize_t preadv2 (int @var{fd}, const struct iovec *@var{iov}, int @var{iovcnt}, off_t @var{offset}, int @var{flags})
>>> +@safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}}
>>> +@c This is a syscall for Linux v4.6.  The sysdeps/posix fallback emulation
>>> +@c is also MT-Safe since it calls preadv.
>>> +
>>> +This function is similar to the @code{preadv} function, with the difference
>>> +it adds an extra @var{flags} parameter of type @code{int}.  The supported
>>> +@var{flags} are dependent of the underlying system.  For Linux it supports:
>>> +
>>> +@vtable @code
>>> +@item RWF_HIPRI
>>> +High priority request.  This adds a flag that tells the file system that
>>> +this is a high priority request for which it is worth to poll the hardware.
>>> +The flag is purely advisory and can be ignored if not supported.  The
>>> +@var{fd} must be opened using @code{O_DIRECT}.
>>> +
>>> +@item RWF_DSYNC
>>> +Per-IO synchronization as if the file was opened with @code{O_DSYNC} flag.
>>> +
>>> +@item RWF_SYNC
>>> +Per-IO synchronization as if the file was opened with @code{O_SYNC} flag.
>>> +@end vtable
>>> +
>>> +When the source file is compiled with @code{_FILE_OFFSET_BITS == 64} the
>>> +@code{preadv2} function is in fact @code{preadv64v2} and the type
>>> +@code{off_t} has 64 bits, which makes it possible to handle files up to
>>> +@twoexp{63} bytes in length.
>>> +
>>> +The return value is a count of bytes (@emph{not} buffers) read, @math{0}
>>> +indicating end-of-file, or @math{-1} indicating an error.  The possible
>>> +errors are the same as in @code{preadv} with the addition of:
>>> +
>>> +@table @code
>>> +
>>> +@item EOPNOTSUPP
>>> +
>>> +@c The default sysdeps/posix code will return it for any flags value
>>> +@c different than 0.
>>> +An unsupported @var{flags} was used.
>>> +
>>> +@end table
>>> +
>>> +@end deftypefun
>>> +
>>> +@comment unistd.h
>>> +@comment GNU
>>> +@deftypefun ssize_t preadv64v2 (int @var{fd}, const struct iovec *@var{iov}, int @var{iovcnt}, off64_t @var{offset}, int @var{flags})
>>> +@safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}}
>>> +@c This is a syscall for Linux v4.6.  The sysdeps/posix fallback emulation
>>> +@c is also MT-Safe since it calls preadv.
>>> +
>>> +This function is similar to the @code{preadv2} function with the difference
>>> +is that the @var{offset} parameter is of type @code{off64_t} instead of
>>> +@code{off_t}.  It makes it possible on 32 bit machines to address
>>> +files larger than @twoexp{31} bytes and up to @twoexp{63} bytes.  The
>>> +file descriptor @code{filedes} must be opened using @code{open64} since
>>> +otherwise the large offsets possible with @code{off64_t} will lead to
>>> +errors with a descriptor in small file mode.
>>> +
>>> +When the source file is compiled using @code{_FILE_OFFSET_BITS == 64} on a
>>> +32 bit machine this function is actually available under the name
>>> +@code{preadv2} and so transparently replaces the 32 bit interface.
>>> +@end deftypefun
>>> +
>>> +
>>> +@comment sys/uio.h
>>> +@comment GNU
>>> +@deftypefun ssize_t pwritev2 (int @var{fd}, const struct iovec *@var{iov}, int @var{iovcnt}, off_t @var{offset}, int @var{flags})
>>> +@safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}}
>>> +@c This is a syscall for Linux v4.6.  The sysdeps/posix fallback emulation
>>> +@c is also MT-Safe since it calls pwritev.
>>> +
>>> +This function is similar to the @code{pwritev} function, with the difference
>>> +it adds an extra @var{flags} parameter of type @code{int}.  The supported
>>> +@var{flags} are dependent of the underlying system and for Linux it supports
>>> +the same ones as for @code{preadv2}.
>>> +
>>> +When the source file is compiled with @code{_FILE_OFFSET_BITS == 64} the
>>> +@code{pwritev2} function is in fact @code{pwritev64v2} and the type
>>> +@code{off_t} has 64 bits, which makes it possible to handle files up to
>>> +@twoexp{63} bytes in length.
>>> +
>>> +The return value is a count of bytes (@emph{not} buffers) write, @math{0}
>>> +indicating end-of-file, or @math{-1} indicating an error.  The possible
>>> +errors are the same as in @code{preadv2}.
>>> +@end deftypefun
>>> +
>>> +@comment unistd.h
>>> +@comment GNU
>>> +@deftypefun ssize_t pwritev64v2 (int @var{fd}, const struct iovec *@var{iov}, int @var{iovcnt}, off64_t @var{offset}, int @var{flags})
>>> +@safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}}
>>> +@c This is a syscall for Linux v4.6.  The sysdeps/posix fallback emulation
>>> +@c is also MT-Safe since it calls pwritev.
>>> +
>>> +This function is similar to the @code{pwritev2} function with the difference
>>> +is that the @var{offset} parameter is of type @code{off64_t} instead of
>>> +@code{off_t}.  It makes it possible on 32 bit machines to address
>>> +files larger than @twoexp{31} bytes and up to @twoexp{63} bytes.  The
>>> +file descriptor @code{filedes} must be opened using @code{open64} since
>>> +otherwise the large offsets possible with @code{off64_t} will lead to
>>> +errors with a descriptor in small file mode.
>>> +
>>> +When the source file is compiled using @code{_FILE_OFFSET_BITS == 64} on a
>>> +32 bit machine this function is actually available under the name
>>> +@code{pwritev2} and so transparently replaces the 32 bit interface.
>>> +@end deftypefun
>>> +
>>>  
>>>  @node File Position Primitive
>>>  @section Setting the File Position of a Descriptor
>>> diff --git a/misc/Makefile b/misc/Makefile
>>> index 622da67..bed46d7 100644
>>> --- a/misc/Makefile
>>> +++ b/misc/Makefile
>>> @@ -39,6 +39,7 @@ headers	:= sys/uio.h bits/uio.h sys/ioctl.h bits/ioctls.h bits/ioctl-types.h \
>>>  
>>>  routines := brk sbrk sstk ioctl \
>>>  	    readv writev preadv preadv64 pwritev pwritev64 \
>>> +	    preadv2 preadv64v2 pwritev2 pwritev64v2 \
>>>  	    setreuid setregid \
>>>  	    seteuid setegid \
>>>  	    getpagesize \
>>> @@ -79,7 +80,9 @@ gpl2lgpl := error.c error.h
>>>  tests := tst-dirname tst-tsearch tst-fdset tst-efgcvt tst-mntent tst-hsearch \
>>>  	 tst-error1 tst-pselect tst-insremque tst-mntent2 bug-hsearch1 \
>>>  	 tst-mntent-blank-corrupt tst-mntent-blank-passno bug18240 \
>>> -	 tst-preadvwritev tst-preadvwritev64 tst-makedev tst-empty \
>>> +	 tst-preadvwritev tst-preadvwritev64 tst-preadvwritev2 \
>>> +	 tst-preadvwritev64v2 \
>>> +	 tst-makedev tst-empty \
>>>  	 tst-atomic tst-atomic-long
>>>  tests-static := tst-empty
>>>  
>>> diff --git a/misc/Versions b/misc/Versions
>>> index f2c90ff..bafda78 100644
>>> --- a/misc/Versions
>>> +++ b/misc/Versions
>>> @@ -155,6 +155,9 @@ libc {
>>>    GLIBC_2.25 {
>>>      gnu_dev_major; gnu_dev_minor; gnu_dev_makedev;
>>>    }
>>> +  GLIBC_2.26 {
>>> +    preadv2; preadv64v2; pwritev2; pwritev64v2;
>>> +  }
>>>    GLIBC_PRIVATE {
>>>      __madvise;
>>>      __mktemp;
>>> diff --git a/misc/preadv2.c b/misc/preadv2.c
>>> new file mode 100644
>>> index 0000000..a62dcaa
>>> --- /dev/null
>>> +++ b/misc/preadv2.c
>>> @@ -0,0 +1,30 @@
>>> +/* Default implementation of preadv2.
>>> +   Copyright (C) 2017 Free Software Foundation, Inc.
>>> +   This file is part of the GNU C Library.
>>> +
>>> +   The GNU C Library is free software; you can redistribute it and/or
>>> +   modify it under the terms of the GNU Lesser General Public
>>> +   License as published by the Free Software Foundation; either
>>> +   version 2.1 of the License, or (at your option) any later version.
>>> +
>>> +   The GNU C Library is distributed in the hope that it will be useful,
>>> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
>>> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>>> +   Lesser General Public License for more details.
>>> +
>>> +   You should have received a copy of the GNU Lesser General Public
>>> +   License along with the GNU C Library; if not, see
>>> +   <http://www.gnu.org/licenses/>.  */
>>> +
>>> +#include <sys/uio.h>
>>> +
>>> +/* Same as preadv but with an additional flags argument.  */
>>> +ssize_t
>>> +preadv2 (int fd, const struct iovec *vector, int count, off_t offset,
>>> +	 int flags)
>>> +{
>>> +  __set_errno (ENOSYS);
>>> +  return -1;
>>> +}
>>> +
>>> +stub_warning (preadv2)
>>> diff --git a/misc/preadv64v2.c b/misc/preadv64v2.c
>>> new file mode 100644
>>> index 0000000..a802c2f
>>> --- /dev/null
>>> +++ b/misc/preadv64v2.c
>>> @@ -0,0 +1,30 @@
>>> +/* Default implementation of preadv2 (LFS version).
>>> +   Copyright (C) 2017 Free Software Foundation, Inc.
>>> +   This file is part of the GNU C Library.
>>> +
>>> +   The GNU C Library is free software; you can redistribute it and/or
>>> +   modify it under the terms of the GNU Lesser General Public
>>> +   License as published by the Free Software Foundation; either
>>> +   version 2.1 of the License, or (at your option) any later version.
>>> +
>>> +   The GNU C Library is distributed in the hope that it will be useful,
>>> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
>>> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>>> +   Lesser General Public License for more details.
>>> +
>>> +   You should have received a copy of the GNU Lesser General Public
>>> +   License along with the GNU C Library; if not, see
>>> +   <http://www.gnu.org/licenses/>.  */
>>> +
>>> +#include <sys/uio.h>
>>> +
>>> +/* Same as preadv64 but with an addional flag argument.  */
>>> +ssize_t
>>> +preadv64v2 (int fd, const struct iovec *vector, int count, off64_t offset,
>>> +	    int flags)
>>> +{
>>> +  __set_errno (ENOSYS);
>>> +  return -1;
>>> +}
>>> +
>>> +stub_warning (preadv64v2)
>>> diff --git a/misc/pwritev2.c b/misc/pwritev2.c
>>> new file mode 100644
>>> index 0000000..b9e0727
>>> --- /dev/null
>>> +++ b/misc/pwritev2.c
>>> @@ -0,0 +1,30 @@
>>> +/* Default implementation of pwritev2.
>>> +   Copyright (C) 2017 Free Software Foundation, Inc.
>>> +   This file is part of the GNU C Library.
>>> +
>>> +   The GNU C Library is free software; you can redistribute it and/or
>>> +   modify it under the terms of the GNU Lesser General Public
>>> +   License as published by the Free Software Foundation; either
>>> +   version 2.1 of the License, or (at your option) any later version.
>>> +
>>> +   The GNU C Library is distributed in the hope that it will be useful,
>>> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
>>> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>>> +   Lesser General Public License for more details.
>>> +
>>> +   You should have received a copy of the GNU Lesser General Public
>>> +   License along with the GNU C Library; if not, see
>>> +   <http://www.gnu.org/licenses/>.  */
>>> +
>>> +#include <sys/uio.h>
>>> +
>>> +/* Same as pwritev but with an additional flags argument.  */
>>> +ssize_t
>>> +pwritev2 (int fd, const struct iovec *vector, int count, off_t offset,
>>> +	  int flags)
>>> +{
>>> +  __set_errno (ENOSYS);
>>> +  return -1;
>>> +}
>>> +
>>> +stub_warning (pwritev2)
>>> diff --git a/misc/pwritev64v2.c b/misc/pwritev64v2.c
>>> new file mode 100644
>>> index 0000000..1f874f0
>>> --- /dev/null
>>> +++ b/misc/pwritev64v2.c
>>> @@ -0,0 +1,30 @@
>>> +/* Default implementation of pwritev2 (LFS version).
>>> +   Copyright (C) 2017 Free Software Foundation, Inc.
>>> +   This file is part of the GNU C Library.
>>> +
>>> +   The GNU C Library is free software; you can redistribute it and/or
>>> +   modify it under the terms of the GNU Lesser General Public
>>> +   License as published by the Free Software Foundation; either
>>> +   version 2.1 of the License, or (at your option) any later version.
>>> +
>>> +   The GNU C Library is distributed in the hope that it will be useful,
>>> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
>>> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>>> +   Lesser General Public License for more details.
>>> +
>>> +   You should have received a copy of the GNU Lesser General Public
>>> +   License along with the GNU C Library; if not, see
>>> +   <http://www.gnu.org/licenses/>.  */
>>> +
>>> +#include <sys/uio.h>
>>> +
>>> +/* Same as preadv64 but with an addional flag argument.  */
>>> +ssize_t
>>> +pwritev64v2 (int fd, const struct iovec *vector, int count, off64_t offset,
>>> +	     int flags)
>>> +{
>>> +  __set_errno (ENOSYS);
>>> +  return -1;
>>> +}
>>> +
>>> +stub_warning (pwritev64v2)
>>> diff --git a/misc/sys/uio.h b/misc/sys/uio.h
>>> index e80f013..66c22f0 100644
>>> --- a/misc/sys/uio.h
>>> +++ b/misc/sys/uio.h
>>> @@ -76,6 +76,7 @@ extern ssize_t preadv (int __fd, const struct iovec *__iovec, int __count,
>>>     __THROW.  */
>>>  extern ssize_t pwritev (int __fd, const struct iovec *__iovec, int __count,
>>>  			__off_t __offset) __wur;
>>> +
>>>  # else
>>>  #  ifdef __REDIRECT
>>>  extern ssize_t __REDIRECT (preadv, (int __fd, const struct iovec *__iovec,
>>> @@ -117,6 +118,46 @@ extern ssize_t pwritev64 (int __fd, const struct iovec *__iovec, int __count,
>>>  # endif
>>>  #endif	/* Use misc.  */
>>>  
>>> +
>>> +#ifdef __USE_GNU
>>> +# ifndef __USE_FILE_OFFSET64
>>> +/* Same as preadv but with an additional flag argumenti defined at uio.h.  */
>>> +extern ssize_t preadv2 (int __fp, const struct iovec *__iovec, int __count,
>>> +			__off_t __offset, int ___flags) __wur;
>>> +
>>> +/* Same as preadv but with an additional flag argument defined at uio.h.  */
>>> +extern ssize_t pwritev2 (int __fd, const struct iovec *__iodev, int __count,
>>> +			 __off_t __offset, int __flags) __wur;
>>> +
>>> +# else
>>> +#  ifdef __REDIRECT
>>> +extern ssize_t __REDIRECT (pwritev2, (int __fd, const struct iovec *__iovec,
>>> +				      int __count, __off64_t __offset,
>>> +				      int __flags),
>>> +			   pwritev64v2) __wur;
>>> +extern ssize_t __REDIRECT (preadv2, (int __fd, const struct iovec *__iovec,
>>> +				     int __count, __off64_t __offset,
>>> +				     int __flags),
>>> +			   preadv64v2) __wur;
>>> +#  else
>>> +#   define preadv2 preadv64v2
>>> +#   define pwritev2 pwritev64v2
>>> +#  endif
>>> +# endif
>>> +
>>> +# ifdef __USE_LARGEFILE64
>>> +/* Same as preadv but with an additional flag argumenti defined at uio.h.  */
>>> +extern ssize_t preadv64v2 (int __fp, const struct iovec *__iovec,
>>> +			   int __count, __off64_t __offset,
>>> +			   int ___flags) __wur;
>>> +
>>> +/* Same as preadv but with an additional flag argument defined at uio.h.  */
>>> +extern ssize_t pwritev64v2 (int __fd, const struct iovec *__iodev,
>>> +			    int __count, __off64_t __offset,
>>> +			    int __flags) __wur;
>>> +# endif
>>> +#endif /* Use GNU.  */
>>> +
>>>  __END_DECLS
>>>  
>>>  #endif /* sys/uio.h */
>>> diff --git a/misc/tst-preadvwritev-common.c b/misc/tst-preadvwritev-common.c
>>> index 5540dfb..676d495 100644
>>> --- a/misc/tst-preadvwritev-common.c
>>> +++ b/misc/tst-preadvwritev-common.c
>>> @@ -18,6 +18,7 @@
>>>  
>>>  #include <stdio.h>
>>>  #include <stdint.h>
>>> +#include <errno.h>
>>>  #include <string.h>
>>>  #include <sys/uio.h>
>>>  #include <sys/stat.h>
>>> @@ -39,6 +40,16 @@ do_prepare (int argc, char **argv)
>>>  }
>>>  #define PREPARE do_prepare
>>>  
>>> +#ifndef PREADV
>>> +# define PREADV(__fd, __iov, __iovcnt, __offset) \
>>> +  preadv (__fd, __iov, __iovcnt, __offset)
>>> +#endif
>>> +
>>> +#ifndef PWRITEV
>>> +# define PWRITEV(__fd, __iov, __iovcnt, __offset) \
>>> +  pwritev (__fd, __iov, __iovcnt, __offset)
>>> +#endif
>>> +
>>>  static int
>>>  do_test_with_offset (off_t offset)
>>>  {
>>> @@ -58,13 +69,13 @@ do_test_with_offset (off_t offset)
>>>    iov[1].iov_base = buf2;
>>>    iov[1].iov_len = sizeof buf2;
>>>  
>>> -  ret = pwritev (temp_fd, iov, 2, offset);
>>> +  ret = PWRITEV (temp_fd, iov, 2, offset);
>>>    if (ret == -1)
>>>      FAIL_RET ("first pwritev returned -1");
>>>    if (ret != (sizeof buf1 + sizeof buf2))
>>>      FAIL_RET ("first pwritev returned an unexpected value");
>>>  
>>> -  ret = pwritev (temp_fd, iov, 2, sizeof buf1 + sizeof buf2 + offset);
>>> +  ret = PWRITEV (temp_fd, iov, 2, sizeof buf1 + sizeof buf2 + offset);
>>>    if (ret == -1)
>>>      FAIL_RET ("second pwritev returned -1");
>>>    if (ret != (sizeof buf1 + sizeof buf2))
>>> @@ -82,7 +93,7 @@ do_test_with_offset (off_t offset)
>>>    iov[1].iov_len = sizeof buf4;
>>>  
>>>    /* Now read two buffer with 32 and 64 bytes respectively.  */
>>> -  ret = preadv (temp_fd, iov, 2, offset);
>>> +  ret = PREADV (temp_fd, iov, 2, offset);
>>>    if (ret == -1)
>>>      FAIL_RET ("first preadv returned -1");
>>>    if (ret != (sizeof buf3 + sizeof buf4))
>>> @@ -93,7 +104,7 @@ do_test_with_offset (off_t offset)
>>>    if (memcmp (buf2, buf4, sizeof buf2) != 0)
>>>      FAIL_RET ("second buffer from first preadv different than expected");
>>>  
>>> -  ret = preadv (temp_fd, iov, 2, sizeof buf3 + sizeof buf4 + offset);
>>> +  ret = PREADV (temp_fd, iov, 2, sizeof buf3 + sizeof buf4 + offset);
>>>    if (ret == -1)
>>>      FAIL_RET ("second preadv returned -1");
>>>    if (ret != (sizeof buf3 + sizeof buf4))
>>> diff --git a/misc/tst-preadvwritev2.c b/misc/tst-preadvwritev2.c
>>> new file mode 100644
>>> index 0000000..cf36272
>>> --- /dev/null
>>> +++ b/misc/tst-preadvwritev2.c
>>> @@ -0,0 +1,31 @@
>>> +/* Tests for preadv2 and pwritev2.
>>> +   Copyright (C) 2016-2017 Free Software Foundation, Inc.
>>> +   This file is part of the GNU C Library.
>>> +
>>> +   The GNU C Library is free software; you can redistribute it and/or
>>> +   modify it under the terms of the GNU Lesser General Public
>>> +   License as published by the Free Software Foundation; either
>>> +   version 2.1 of the License, or (at your option) any later version.
>>> +
>>> +   The GNU C Library is distributed in the hope that it will be useful,
>>> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
>>> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>>> +   Lesser General Public License for more details.
>>> +
>>> +   You should have received a copy of the GNU Lesser General Public
>>> +   License along with the GNU C Library; if not, see
>>> +   <http://www.gnu.org/licenses/>.  */
>>> +
>>> +#define PREADV(__fd, __iov, __iovcnt, __offset) \
>>> +  preadv2 (__fd, __iov, __iovcnt, __offset, 0)
>>> +
>>> +#define PWRITEV(__fd, __iov, __iovcnt, __offset) \
>>> +  pwritev2 (__fd, __iov, __iovcnt, __offset, 0)
>>> +
>>> +#include "tst-preadvwritev-common.c"
>>> +
>>> +static int
>>> +do_test (void)
>>> +{
>>> +  return do_test_with_offset (0);
>>> +}
>>> diff --git a/misc/tst-preadvwritev64v2.c b/misc/tst-preadvwritev64v2.c
>>> new file mode 100644
>>> index 0000000..8d0c48e
>>> --- /dev/null
>>> +++ b/misc/tst-preadvwritev64v2.c
>>> @@ -0,0 +1,33 @@
>>> +/* Tests for preadv2 and pwritev2 (LFS version).
>>> +   Copyright (C) 2017 Free Software Foundation, Inc.
>>> +   This file is part of the GNU C Library.
>>> +
>>> +   The GNU C Library is free software; you can redistribute it and/or
>>> +   modify it under the terms of the GNU Lesser General Public
>>> +   License as published by the Free Software Foundation; either
>>> +   version 2.1 of the License, or (at your option) any later version.
>>> +
>>> +   The GNU C Library is distributed in the hope that it will be useful,
>>> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
>>> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>>> +   Lesser General Public License for more details.
>>> +
>>> +   You should have received a copy of the GNU Lesser General Public
>>> +   License along with the GNU C Library; if not, see
>>> +   <http://www.gnu.org/licenses/>.  */
>>> +
>>> +#define _FILE_OFFSET_BITS 64
>>> +
>>> +#define PREADV(__fd, __iov, __iovcnt, __offset) \
>>> +  preadv2 (__fd, __iov, __iovcnt, __offset, 0)
>>> +
>>> +#define PWRITEV(__fd, __iov, __iovcnt, __offset) \
>>> +  pwritev2 (__fd, __iov, __iovcnt, __offset, 0)
>>> +
>>> +#include "tst-preadvwritev-common.c"
>>> +
>>> +static int
>>> +do_test (void)
>>> +{
>>> +  return do_test_with_offset (0);
>>> +}
>>> diff --git a/nptl/tst-cancel4.c b/nptl/tst-cancel4.c
>>> index e66961f..7a560a1 100644
>>> --- a/nptl/tst-cancel4.c
>>> +++ b/nptl/tst-cancel4.c
>>> @@ -1079,6 +1079,75 @@ tf_pwritev (void *arg)
>>>  }
>>>  
>>>  static void *
>>> +tf_pwritev2 (void *arg)
>>> +{
>>> +  int fd;
>>> +
>>> +  if (arg == NULL)
>>> +    /* XXX If somebody can provide a portable test case in which pwritev2
>>> +       blocks we can enable this test to run in both rounds.  */
>>> +    abort ();
>>> +
>>> +  errno = 0;
>>> +
>>> +  char fname[] = "/tmp/tst-cancel4-fd-XXXXXX";
>>> +  tempfd = fd = mkstemp (fname);
>>> +  if (fd == -1)
>>> +    FAIL_EXIT1 ("mkstemp: %m");
>>> +  unlink (fname);
>>> +
>>> +  xpthread_barrier_wait (&b2);
>>> +
>>> +  xpthread_barrier_wait (&b2);
>>> +
>>> +  ssize_t s;
>>> +  pthread_cleanup_push (cl, NULL);
>>> +
>>> +  char buf[WRITE_BUFFER_SIZE];
>>> +  memset (buf, '\0', sizeof (buf));
>>> +  struct iovec iov[1] = { [0] = { .iov_base = buf, .iov_len = sizeof (buf) } };
>>> +  s = pwritev2 (fd, iov, 1, 0, 0);
>>> +
>>> +  pthread_cleanup_pop (0);
>>> +
>>> +  FAIL_EXIT1 ("pwritev2 returns with %zd", s);
>>> +}
>>> +
>>> +static void *
>>> +tf_preadv2 (void *arg)
>>> +{
>>> +  int fd;
>>> +
>>> +  if (arg == NULL)
>>> +    /* XXX If somebody can provide a portable test case in which preadv2
>>> +       blocks we can enable this test to run in both rounds.  */
>>> +    abort ();
>>> +
>>> +  errno = 0;
>>> +
>>> +  char fname[] = "/tmp/tst-cancel4-fd-XXXXXX";
>>> +  tempfd = fd = mkstemp (fname);
>>> +  if (fd == -1)
>>> +    FAIL_EXIT1 ("mkstemp failed: %m");
>>> +  unlink (fname);
>>> +
>>> +  xpthread_barrier_wait (&b2);
>>> +
>>> +  xpthread_barrier_wait (&b2);
>>> +
>>> +  ssize_t s;
>>> +  pthread_cleanup_push (cl, NULL);
>>> +
>>> +  char buf[100];
>>> +  struct iovec iov[1] = { [0] = { .iov_base = buf, .iov_len = sizeof (buf) } };
>>> +  s = preadv2 (fd, iov, 1, 0, 0);
>>> +
>>> +  pthread_cleanup_pop (0);
>>> +
>>> +  FAIL_EXIT1 ("preadv2 returns with %zd", s);
>>> +}
>>> +
>>> +static void *
>>>  tf_fsync (void *arg)
>>>  {
>>>    if (arg == NULL)
>>> @@ -1473,7 +1542,9 @@ struct cancel_tests tests[] =
>>>    ADD_TEST (recvfrom, 2, 0),
>>>    ADD_TEST (recvmsg, 2, 0),
>>>    ADD_TEST (preadv, 2, 1),
>>> +  ADD_TEST (preadv2, 2, 1),
>>>    ADD_TEST (pwritev, 2, 1),
>>> +  ADD_TEST (pwritev2, 2, 1),
>>>    ADD_TEST (open, 2, 1),
>>>    ADD_TEST (close, 2, 1),
>>>    ADD_TEST (pread, 2, 1),
>>> diff --git a/sysdeps/posix/preadv2.c b/sysdeps/posix/preadv2.c
>>> new file mode 100644
>>> index 0000000..2a7cf11
>>> --- /dev/null
>>> +++ b/sysdeps/posix/preadv2.c
>>> @@ -0,0 +1,38 @@
>>> +/* Generic version of preadv2.
>>> +   Copyright (C) 2017 Free Software Foundation, Inc.
>>> +   This file is part of the GNU C Library.
>>> +
>>> +   The GNU C Library is free software; you can redistribute it and/or
>>> +   modify it under the terms of the GNU Lesser General Public
>>> +   License as published by the Free Software Foundation; either
>>> +   version 2.1 of the License, or (at your option) any later version.
>>> +
>>> +   The GNU C Library is distributed in the hope that it will be useful,
>>> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
>>> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>>> +   Lesser General Public License for more details.
>>> +
>>> +   You should have received a copy of the GNU Lesser General Public
>>> +   License along with the GNU C Library; if not, see
>>> +   <http://www.gnu.org/licenses/>.  */
>>> +
>>> +#include <unistd.h>
>>> +#include <sys/uio.h>
>>> +
>>> +#ifndef __OFF_T_MATCHES_OFF64_T
>>> +
>>> +/* Since we define no flags for preadv2 just route to preadv.  */
>>> +ssize_t
>>> +preadv2 (int fd, const struct iovec *vector, int count, OFF_T offset,
>>> +	 int flags)
>>> +{
>>> +  if (flags != 0)
>>> +    {
>>> +      __set_errno (EOPNOTSUPP);
>>> +      return -1;
>>> +    }
>>> +
>>> +  return preadv (fd, vector, count, offset);
>>> +}
>>> +
>>> +#endif
>>> diff --git a/sysdeps/posix/preadv64v2.c b/sysdeps/posix/preadv64v2.c
>>> new file mode 100644
>>> index 0000000..e084f3f
>>> --- /dev/null
>>> +++ b/sysdeps/posix/preadv64v2.c
>>> @@ -0,0 +1,37 @@
>>> +/* Generic version of preadv2.
>>> +   Copyright (C) 2017 Free Software Foundation, Inc.
>>> +   This file is part of the GNU C Library.
>>> +
>>> +   The GNU C Library is free software; you can redistribute it and/or
>>> +   modify it under the terms of the GNU Lesser General Public
>>> +   License as published by the Free Software Foundation; either
>>> +   version 2.1 of the License, or (at your option) any later version.
>>> +
>>> +   The GNU C Library is distributed in the hope that it will be useful,
>>> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
>>> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>>> +   Lesser General Public License for more details.
>>> +
>>> +   You should have received a copy of the GNU Lesser General Public
>>> +   License along with the GNU C Library; if not, see
>>> +   <http://www.gnu.org/licenses/>.  */
>>> +
>>> +#include <unistd.>
>>> +#include <sys/uio.h>
>>> +
>>> +ssize_t
>>> +preadv64v2 (int fd, const struct iovec *vector, int count, OFF_T offset,
>>> +	    int flags)
>>> +{
>>> +  if (flags != 0)
>>> +    {
>>> +      __set_errno (EOPNOTSUPP);
>>> +      return -1;
>>> +    }
>>> +
>>> +  return preadv64 (fd, vector, count, offset);
>>> +}
>>> +
>>> +#ifdef __OFF_T_MATCHES_OFF64_T
>>> +strong_alias (preadv64v2, preadv2)
>>> +#endif
>>> diff --git a/sysdeps/posix/pwritev2.c b/sysdeps/posix/pwritev2.c
>>> new file mode 100644
>>> index 0000000..5b7650c
>>> --- /dev/null
>>> +++ b/sysdeps/posix/pwritev2.c
>>> @@ -0,0 +1,38 @@
>>> +/* Generic version of pwritev2.
>>> +   Copyright (C) 2017 Free Software Foundation, Inc.
>>> +   This file is part of the GNU C Library.
>>> +
>>> +   The GNU C Library is free software; you can redistribute it and/or
>>> +   modify it under the terms of the GNU Lesser General Public
>>> +   License as published by the Free Software Foundation; either
>>> +   version 2.1 of the License, or (at your option) any later version.
>>> +
>>> +   The GNU C Library is distributed in the hope that it will be useful,
>>> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
>>> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>>> +   Lesser General Public License for more details.
>>> +
>>> +   You should have received a copy of the GNU Lesser General Public
>>> +   License along with the GNU C Library; if not, see
>>> +   <http://www.gnu.org/licenses/>.  */
>>> +
>>> +#include <unistd.h>
>>> +#include <sys/uio.h>
>>> +
>>> +#ifndef __OFF_T_MATCHES_OFF64_T
>>> +
>>> +/* Since we define no flags for pwritev2 just route to pwritev.  */
>>> +ssize_t
>>> +pwritev2 (int fd, const struct iovec *vector, int count, OFF_T offset,
>>> +	  int flags)
>>> +{
>>> +  if (flags != 0)
>>> +    {
>>> +      __set_errno (EOPNOTSUPP);
>>> +      return -1;
>>> +    }
>>> +
>>> +  return pwritev (fd, vector, count, offset);
>>> +}
>>> +
>>> +#endif
>>> diff --git a/sysdeps/posix/pwritev64v2.c b/sysdeps/posix/pwritev64v2.c
>>> new file mode 100644
>>> index 0000000..d9727b9
>>> --- /dev/null
>>> +++ b/sysdeps/posix/pwritev64v2.c
>>> @@ -0,0 +1,38 @@
>>> +/* Generic version of pwritev2.
>>> +   Copyright (C) 2017 Free Software Foundation, Inc.
>>> +   This file is part of the GNU C Library.
>>> +
>>> +   The GNU C Library is free software; you can redistribute it and/or
>>> +   modify it under the terms of the GNU Lesser General Public
>>> +   License as published by the Free Software Foundation; either
>>> +   version 2.1 of the License, or (at your option) any later version.
>>> +
>>> +   The GNU C Library is distributed in the hope that it will be useful,
>>> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
>>> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>>> +   Lesser General Public License for more details.
>>> +
>>> +   You should have received a copy of the GNU Lesser General Public
>>> +   License along with the GNU C Library; if not, see
>>> +   <http://www.gnu.org/licenses/>.  */
>>> +
>>> +#include <unistd.h>
>>> +#include <sys/uio.h>
>>> +
>>> +/* Since we define no flags for pwritev2 just route to pwritev.  */ 
>>> +ssize_t
>>> +pwritev64v2 (int fd, const struct iovec *vector, int count, OFF_T offset,
>>> +	     int flags)
>>> +{
>>> +  if (flags != 0)
>>> +    {
>>> +      __set_errno (EOPNOTSUPP);
>>> +      return -1;
>>> +    }
>>> +
>>> +  return pwritev64 (fd, vector, count, offset);
>>> +}
>>> +
>>> +#ifdef __OFF_T_MATCHES_OFF64_T
>>> +strong_alias (pwritev64v2, pwritev2)
>>> +#endif
>>> diff --git a/sysdeps/unix/sysv/linux/aarch64/libc.abilist b/sysdeps/unix/sysv/linux/aarch64/libc.abilist
>>> index 58d768c..296f2a5 100644
>>> --- a/sysdeps/unix/sysv/linux/aarch64/libc.abilist
>>> +++ b/sysdeps/unix/sysv/linux/aarch64/libc.abilist
>>> @@ -2097,3 +2097,8 @@ GLIBC_2.25 getrandom F
>>>  GLIBC_2.25 strfromd F
>>>  GLIBC_2.25 strfromf F
>>>  GLIBC_2.25 strfroml F
>>> +GLIBC_2.26 GLIBC_2.26 A
>>> +GLIBC_2.26 preadv2 F
>>> +GLIBC_2.26 preadv64v2 F
>>> +GLIBC_2.26 pwritev2 F
>>> +GLIBC_2.26 pwritev64v2 F
>>> diff --git a/sysdeps/unix/sysv/linux/alpha/libc.abilist b/sysdeps/unix/sysv/linux/alpha/libc.abilist
>>> index 906050d..8006e72 100644
>>> --- a/sysdeps/unix/sysv/linux/alpha/libc.abilist
>>> +++ b/sysdeps/unix/sysv/linux/alpha/libc.abilist
>>> @@ -2008,6 +2008,11 @@ GLIBC_2.25 getrandom F
>>>  GLIBC_2.25 strfromd F
>>>  GLIBC_2.25 strfromf F
>>>  GLIBC_2.25 strfroml F
>>> +GLIBC_2.26 GLIBC_2.26 A
>>> +GLIBC_2.26 preadv2 F
>>> +GLIBC_2.26 preadv64v2 F
>>> +GLIBC_2.26 pwritev2 F
>>> +GLIBC_2.26 pwritev64v2 F
>>>  GLIBC_2.3 GLIBC_2.3 A
>>>  GLIBC_2.3 __ctype_b_loc F
>>>  GLIBC_2.3 __ctype_tolower_loc F
>>> diff --git a/sysdeps/unix/sysv/linux/arm/libc.abilist b/sysdeps/unix/sysv/linux/arm/libc.abilist
>>> index 66112dd..29f9688 100644
>>> --- a/sysdeps/unix/sysv/linux/arm/libc.abilist
>>> +++ b/sysdeps/unix/sysv/linux/arm/libc.abilist
>>> @@ -98,6 +98,11 @@ GLIBC_2.25 getrandom F
>>>  GLIBC_2.25 strfromd F
>>>  GLIBC_2.25 strfromf F
>>>  GLIBC_2.25 strfroml F
>>> +GLIBC_2.26 GLIBC_2.26 A
>>> +GLIBC_2.26 preadv2 F
>>> +GLIBC_2.26 preadv64v2 F
>>> +GLIBC_2.26 pwritev2 F
>>> +GLIBC_2.26 pwritev64v2 F
>>>  GLIBC_2.4 GLIBC_2.4 A
>>>  GLIBC_2.4 _Exit F
>>>  GLIBC_2.4 _IO_2_1_stderr_ D 0xa0
>>> diff --git a/sysdeps/unix/sysv/linux/bits/uio.h b/sysdeps/unix/sysv/linux/bits/uio.h
>>> index 1583f04..d5701f8 100644
>>> --- a/sysdeps/unix/sysv/linux/bits/uio.h
>>> +++ b/sysdeps/unix/sysv/linux/bits/uio.h
>>> @@ -69,4 +69,10 @@ extern ssize_t process_vm_writev (pid_t __pid, const struct iovec *__lvec,
>>>  __END_DECLS
>>>  
>>>  # endif
>>> +
>>> +/* Flags for preadv2/pwritev2: */
>>> +#define RWF_HIPRI	0x00000001 /* High priority request.  */
>>> +#define RWF_DSYNC	0x00000002 /* per-IO O_DSYNC.  */
>>> +#define RWF_SYNC	0x00000004 /* per-IO O_SYNC.  */
>>> +
>>>  #endif
>>> diff --git a/sysdeps/unix/sysv/linux/hppa/libc.abilist b/sysdeps/unix/sysv/linux/hppa/libc.abilist
>>> index 3ddadd2..e9cfbaf 100644
>>> --- a/sysdeps/unix/sysv/linux/hppa/libc.abilist
>>> +++ b/sysdeps/unix/sysv/linux/hppa/libc.abilist
>>> @@ -1862,6 +1862,11 @@ GLIBC_2.25 getrandom F
>>>  GLIBC_2.25 strfromd F
>>>  GLIBC_2.25 strfromf F
>>>  GLIBC_2.25 strfroml F
>>> +GLIBC_2.26 GLIBC_2.26 A
>>> +GLIBC_2.26 preadv2 F
>>> +GLIBC_2.26 preadv64v2 F
>>> +GLIBC_2.26 pwritev2 F
>>> +GLIBC_2.26 pwritev64v2 F
>>>  GLIBC_2.3 GLIBC_2.3 A
>>>  GLIBC_2.3 __ctype_b_loc F
>>>  GLIBC_2.3 __ctype_tolower_loc F
>>> diff --git a/sysdeps/unix/sysv/linux/i386/libc.abilist b/sysdeps/unix/sysv/linux/i386/libc.abilist
>>> index 977ab90..c6ad3c3 100644
>>> --- a/sysdeps/unix/sysv/linux/i386/libc.abilist
>>> +++ b/sysdeps/unix/sysv/linux/i386/libc.abilist
>>> @@ -2020,6 +2020,11 @@ GLIBC_2.25 getrandom F
>>>  GLIBC_2.25 strfromd F
>>>  GLIBC_2.25 strfromf F
>>>  GLIBC_2.25 strfroml F
>>> +GLIBC_2.26 GLIBC_2.26 A
>>> +GLIBC_2.26 preadv2 F
>>> +GLIBC_2.26 preadv64v2 F
>>> +GLIBC_2.26 pwritev2 F
>>> +GLIBC_2.26 pwritev64v2 F
>>>  GLIBC_2.3 GLIBC_2.3 A
>>>  GLIBC_2.3 __ctype_b_loc F
>>>  GLIBC_2.3 __ctype_tolower_loc F
>>> diff --git a/sysdeps/unix/sysv/linux/ia64/libc.abilist b/sysdeps/unix/sysv/linux/ia64/libc.abilist
>>> index c7edb9a..d0055a2 100644
>>> --- a/sysdeps/unix/sysv/linux/ia64/libc.abilist
>>> +++ b/sysdeps/unix/sysv/linux/ia64/libc.abilist
>>> @@ -1884,6 +1884,11 @@ GLIBC_2.25 getrandom F
>>>  GLIBC_2.25 strfromd F
>>>  GLIBC_2.25 strfromf F
>>>  GLIBC_2.25 strfroml F
>>> +GLIBC_2.26 GLIBC_2.26 A
>>> +GLIBC_2.26 preadv2 F
>>> +GLIBC_2.26 preadv64v2 F
>>> +GLIBC_2.26 pwritev2 F
>>> +GLIBC_2.26 pwritev64v2 F
>>>  GLIBC_2.3 GLIBC_2.3 A
>>>  GLIBC_2.3 __ctype_b_loc F
>>>  GLIBC_2.3 __ctype_tolower_loc F
>>> diff --git a/sysdeps/unix/sysv/linux/kernel-features.h b/sysdeps/unix/sysv/linux/kernel-features.h
>>> index b981466..8ee1af7 100644
>>> --- a/sysdeps/unix/sysv/linux/kernel-features.h
>>> +++ b/sysdeps/unix/sysv/linux/kernel-features.h
>>> @@ -137,3 +137,8 @@
>>>  /* Support for SysV IPC through wired syscalls.  All supported architectures
>>>     either support ipc syscall and/or all the ipc correspondent syscalls.  */
>>>  #define __ASSUME_DIRECT_SYSVIPC_SYSCALLS	1
>>> +
>>> +/* Support for p{read,write}v2 was added in 4.6.  However Linux default
>>> +   implementation does not assume the __ASSUME_* and instead use a fallback
>>> +   implementation based on p{read,write}v and returning an error for
>>> +   non supported flags.  */
>>> diff --git a/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist b/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
>>> index 450be4e..3777676 100644
>>> --- a/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
>>> +++ b/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
>>> @@ -99,6 +99,11 @@ GLIBC_2.25 getrandom F
>>>  GLIBC_2.25 strfromd F
>>>  GLIBC_2.25 strfromf F
>>>  GLIBC_2.25 strfroml F
>>> +GLIBC_2.26 GLIBC_2.26 A
>>> +GLIBC_2.26 preadv2 F
>>> +GLIBC_2.26 preadv64v2 F
>>> +GLIBC_2.26 pwritev2 F
>>> +GLIBC_2.26 pwritev64v2 F
>>>  GLIBC_2.4 GLIBC_2.4 A
>>>  GLIBC_2.4 _Exit F
>>>  GLIBC_2.4 _IO_2_1_stderr_ D 0x98
>>> diff --git a/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist b/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
>>> index 9e016bd..8b1f80c 100644
>>> --- a/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
>>> +++ b/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
>>> @@ -1976,6 +1976,11 @@ GLIBC_2.25 getrandom F
>>>  GLIBC_2.25 strfromd F
>>>  GLIBC_2.25 strfromf F
>>>  GLIBC_2.25 strfroml F
>>> +GLIBC_2.26 GLIBC_2.26 A
>>> +GLIBC_2.26 preadv2 F
>>> +GLIBC_2.26 preadv64v2 F
>>> +GLIBC_2.26 pwritev2 F
>>> +GLIBC_2.26 pwritev64v2 F
>>>  GLIBC_2.3 GLIBC_2.3 A
>>>  GLIBC_2.3 __ctype_b_loc F
>>>  GLIBC_2.3 __ctype_tolower_loc F
>>> diff --git a/sysdeps/unix/sysv/linux/microblaze/libc.abilist b/sysdeps/unix/sysv/linux/microblaze/libc.abilist
>>> index 1a455be..d4db9a8 100644
>>> --- a/sysdeps/unix/sysv/linux/microblaze/libc.abilist
>>> +++ b/sysdeps/unix/sysv/linux/microblaze/libc.abilist
>>> @@ -2097,3 +2097,8 @@ GLIBC_2.25 getrandom F
>>>  GLIBC_2.25 strfromd F
>>>  GLIBC_2.25 strfromf F
>>>  GLIBC_2.25 strfroml F
>>> +GLIBC_2.26 GLIBC_2.26 A
>>> +GLIBC_2.26 preadv2 F
>>> +GLIBC_2.26 preadv64v2 F
>>> +GLIBC_2.26 pwritev2 F
>>> +GLIBC_2.26 pwritev64v2 F
>>> diff --git a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
>>> index 8eb5e66..f430bdb 100644
>>> --- a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
>>> +++ b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
>>> @@ -1951,6 +1951,11 @@ GLIBC_2.25 getrandom F
>>>  GLIBC_2.25 strfromd F
>>>  GLIBC_2.25 strfromf F
>>>  GLIBC_2.25 strfroml F
>>> +GLIBC_2.26 GLIBC_2.26 A
>>> +GLIBC_2.26 preadv2 F
>>> +GLIBC_2.26 preadv64v2 F
>>> +GLIBC_2.26 pwritev2 F
>>> +GLIBC_2.26 pwritev64v2 F
>>>  GLIBC_2.3 GLIBC_2.3 A
>>>  GLIBC_2.3 __ctype_b_loc F
>>>  GLIBC_2.3 __ctype_tolower_loc F
>>> diff --git a/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
>>> index 416d9ac..a4dca19 100644
>>> --- a/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
>>> +++ b/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
>>> @@ -1949,6 +1949,11 @@ GLIBC_2.25 getrandom F
>>>  GLIBC_2.25 strfromd F
>>>  GLIBC_2.25 strfromf F
>>>  GLIBC_2.25 strfroml F
>>> +GLIBC_2.26 GLIBC_2.26 A
>>> +GLIBC_2.26 preadv2 F
>>> +GLIBC_2.26 preadv64v2 F
>>> +GLIBC_2.26 pwritev2 F
>>> +GLIBC_2.26 pwritev64v2 F
>>>  GLIBC_2.3 GLIBC_2.3 A
>>>  GLIBC_2.3 __ctype_b_loc F
>>>  GLIBC_2.3 __ctype_tolower_loc F
>>> diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
>>> index f4949e5..0814fa8 100644
>>> --- a/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
>>> +++ b/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
>>> @@ -1947,6 +1947,11 @@ GLIBC_2.25 getrandom F
>>>  GLIBC_2.25 strfromd F
>>>  GLIBC_2.25 strfromf F
>>>  GLIBC_2.25 strfroml F
>>> +GLIBC_2.26 GLIBC_2.26 A
>>> +GLIBC_2.26 preadv2 F
>>> +GLIBC_2.26 preadv64v2 F
>>> +GLIBC_2.26 pwritev2 F
>>> +GLIBC_2.26 pwritev64v2 F
>>>  GLIBC_2.3 GLIBC_2.3 A
>>>  GLIBC_2.3 __ctype_b_loc F
>>>  GLIBC_2.3 __ctype_tolower_loc F
>>> diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
>>> index c7375ae..a0bdeff 100644
>>> --- a/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
>>> +++ b/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
>>> @@ -1942,6 +1942,11 @@ GLIBC_2.25 getrandom F
>>>  GLIBC_2.25 strfromd F
>>>  GLIBC_2.25 strfromf F
>>>  GLIBC_2.25 strfroml F
>>> +GLIBC_2.26 GLIBC_2.26 A
>>> +GLIBC_2.26 preadv2 F
>>> +GLIBC_2.26 preadv64v2 F
>>> +GLIBC_2.26 pwritev2 F
>>> +GLIBC_2.26 pwritev64v2 F
>>>  GLIBC_2.3 GLIBC_2.3 A
>>>  GLIBC_2.3 __ctype_b_loc F
>>>  GLIBC_2.3 __ctype_tolower_loc F
>>> diff --git a/sysdeps/unix/sysv/linux/nios2/libc.abilist b/sysdeps/unix/sysv/linux/nios2/libc.abilist
>>> index 724a0e3..b201290 100644
>>> --- a/sysdeps/unix/sysv/linux/nios2/libc.abilist
>>> +++ b/sysdeps/unix/sysv/linux/nios2/libc.abilist
>>> @@ -2138,3 +2138,8 @@ GLIBC_2.25 getrandom F
>>>  GLIBC_2.25 strfromd F
>>>  GLIBC_2.25 strfromf F
>>>  GLIBC_2.25 strfroml F
>>> +GLIBC_2.26 GLIBC_2.26 A
>>> +GLIBC_2.26 preadv2 F
>>> +GLIBC_2.26 preadv64v2 F
>>> +GLIBC_2.26 pwritev2 F
>>> +GLIBC_2.26 pwritev64v2 F
>>> diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
>>> index 2dc32b6..6e7ff24 100644
>>> --- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
>>> +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
>>> @@ -1980,6 +1980,11 @@ GLIBC_2.25 getrandom F
>>>  GLIBC_2.25 strfromd F
>>>  GLIBC_2.25 strfromf F
>>>  GLIBC_2.25 strfroml F
>>> +GLIBC_2.26 GLIBC_2.26 A
>>> +GLIBC_2.26 preadv2 F
>>> +GLIBC_2.26 preadv64v2 F
>>> +GLIBC_2.26 pwritev2 F
>>> +GLIBC_2.26 pwritev64v2 F
>>>  GLIBC_2.3 GLIBC_2.3 A
>>>  GLIBC_2.3 __ctype_b_loc F
>>>  GLIBC_2.3 __ctype_tolower_loc F
>>> diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
>>> index 5658109..19c7c7d 100644
>>> --- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
>>> +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
>>> @@ -1985,6 +1985,11 @@ GLIBC_2.25 getrandom F
>>>  GLIBC_2.25 strfromd F
>>>  GLIBC_2.25 strfromf F
>>>  GLIBC_2.25 strfroml F
>>> +GLIBC_2.26 GLIBC_2.26 A
>>> +GLIBC_2.26 preadv2 F
>>> +GLIBC_2.26 preadv64v2 F
>>> +GLIBC_2.26 pwritev2 F
>>> +GLIBC_2.26 pwritev64v2 F
>>>  GLIBC_2.3 GLIBC_2.3 A
>>>  GLIBC_2.3 __ctype_b_loc F
>>>  GLIBC_2.3 __ctype_tolower_loc F
>>> diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist
>>> index c761221..e94ce38 100644
>>> --- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist
>>> +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist
>>> @@ -2185,3 +2185,8 @@ GLIBC_2.25 getrandom F
>>>  GLIBC_2.25 strfromd F
>>>  GLIBC_2.25 strfromf F
>>>  GLIBC_2.25 strfroml F
>>> +GLIBC_2.26 GLIBC_2.26 A
>>> +GLIBC_2.26 preadv2 F
>>> +GLIBC_2.26 preadv64v2 F
>>> +GLIBC_2.26 pwritev2 F
>>> +GLIBC_2.26 pwritev64v2 F
>>> diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist
>>> index 265c769..f3daa33 100644
>>> --- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist
>>> +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist
>>> @@ -99,6 +99,11 @@ GLIBC_2.25 getrandom F
>>>  GLIBC_2.25 strfromd F
>>>  GLIBC_2.25 strfromf F
>>>  GLIBC_2.25 strfroml F
>>> +GLIBC_2.26 GLIBC_2.26 A
>>> +GLIBC_2.26 preadv2 F
>>> +GLIBC_2.26 preadv64v2 F
>>> +GLIBC_2.26 pwritev2 F
>>> +GLIBC_2.26 pwritev64v2 F
>>>  GLIBC_2.3 GLIBC_2.3 A
>>>  GLIBC_2.3 _Exit F
>>>  GLIBC_2.3 _IO_2_1_stderr_ D 0xe0
>>> diff --git a/sysdeps/unix/sysv/linux/preadv.c b/sysdeps/unix/sysv/linux/preadv.c
>>> index 7d971cc..ecabc8c 100644
>>> --- a/sysdeps/unix/sysv/linux/preadv.c
>>> +++ b/sysdeps/unix/sysv/linux/preadv.c
>>> @@ -50,4 +50,6 @@ preadv (int fd, const struct iovec *vector, int count, off_t offset)
>>>  #  define OFF_T off_t
>>>  #  include <sysdeps/posix/preadv_common.c>
>>>  # endif /* __ASSUME_PREADV  */
>>> +
>>> +libc_hidden_def (preadv)
>>>  #endif
>>> diff --git a/sysdeps/unix/sysv/linux/preadv2.c b/sysdeps/unix/sysv/linux/preadv2.c
>>> new file mode 100644
>>> index 0000000..11fe85e
>>> --- /dev/null
>>> +++ b/sysdeps/unix/sysv/linux/preadv2.c
>>> @@ -0,0 +1,55 @@
>>> +/* Linux implementation of preadv2.
>>> +   Copyright (C) 2017 Free Software Foundation, Inc.
>>> +   This file is part of the GNU C Library.
>>> +
>>> +   The GNU C Library is free software; you can redistribute it and/or
>>> +   modify it under the terms of the GNU Lesser General Public
>>> +   License as published by the Free Software Foundation; either
>>> +   version 2.1 of the License, or (at your option) any later version.
>>> +
>>> +   The GNU C Library is distributed in the hope that it will be useful,
>>> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
>>> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>>> +   Lesser General Public License for more details.
>>> +
>>> +   You should have received a copy of the GNU Lesser General Public
>>> +   License along with the GNU C Library; if not, see
>>> +   <http://www.gnu.org/licenses/>.  */
>>> +
>>> +#include <sys/uio.h>
>>> +#include <sysdep-cancel.h>
>>> +
>>> +#ifndef __OFF_T_MATCHES_OFF64_T
>>> +
>>> +# if !defined (__NR_preadv2) && defined (__NR_pread64v2)
>>> +#  define __NR_preadv2 __NR_pread64v2
>>> +# endif
>>> +
>>> +ssize_t
>>> +preadv2 (int fd, const struct iovec *vector, int count, off_t offset,
>>> +	 int flags)
>>> +{
>>> +# ifdef __NR_preadv2
>>> +  ssize_t result = SYSCALL_CANCEL (preadv2, fd, vector, count,
>>> +				   LO_HI_LONG (offset), flags);
>>> +  if (result >= 0 || errno != ENOSYS)
>>> +    return result;
>>> +# endif
>>> +  /* Trying to emulate the preadv2 syscall flags is troublesome:
>>> +
>>> +     * We can not temporary change the file state of the O_DSYNC and O_SYNC
>>> +       flags to emulate RWF_{D}SYNC (attempts to change the state of using
>>> +       fcntl are silently ignored).
>>> +
>>> +     * IOCB_HIPRI requires the file opened in O_DIRECT and uses an internal
>>> +       semantic not provided by any other flag (O_NONBLOCK for instance).  */
>>> +
>>> +  if (flags != 0)
>>> +    {
>>> +      __set_errno (EOPNOTSUPP);
>>> +      return -1;
>>> +    }
>>> +  return preadv (fd, vector, count, offset);
>>> +}
>>> +
>>> +#endif
>>> diff --git a/sysdeps/unix/sysv/linux/preadv64.c b/sysdeps/unix/sysv/linux/preadv64.c
>>> index 66daa74..c96b214 100644
>>> --- a/sysdeps/unix/sysv/linux/preadv64.c
>>> +++ b/sysdeps/unix/sysv/linux/preadv64.c
>>> @@ -48,7 +48,9 @@ preadv64 (int fd, const struct iovec *vector, int count, off64_t offset)
>>>  # define OFF_T off64_t
>>>  # include <sysdeps/posix/preadv_common.c>
>>>  #endif
>>> +libc_hidden_def (preadv64)
>>>  
>>>  #ifdef __OFF_T_MATCHES_OFF64_T
>>>  strong_alias (preadv64, preadv)
>>> +libc_hidden_def (preadv)
>>>  #endif
>>> diff --git a/sysdeps/unix/sysv/linux/preadv64v2.c b/sysdeps/unix/sysv/linux/preadv64v2.c
>>> new file mode 100644
>>> index 0000000..9d7f8c9
>>> --- /dev/null
>>> +++ b/sysdeps/unix/sysv/linux/preadv64v2.c
>>> @@ -0,0 +1,55 @@
>>> +/* Linux implementation of preadv2 (LFS version).
>>> +   Copyright (C) 2017 Free Software Foundation, Inc.
>>> +   This file is part of the GNU C Library.
>>> +
>>> +   The GNU C Library is free software; you can redistribute it and/or
>>> +   modify it under the terms of the GNU Lesser General Public
>>> +   License as published by the Free Software Foundation; either
>>> +   version 2.1 of the License, or (at your option) any later version.
>>> +
>>> +   The GNU C Library is distributed in the hope that it will be useful,
>>> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
>>> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>>> +   Lesser General Public License for more details.
>>> +
>>> +   You should have received a copy of the GNU Lesser General Public
>>> +   License along with the GNU C Library; if not, see
>>> +   <http://www.gnu.org/licenses/>.  */
>>> +
>>> +#include <sys/uio.h>
>>> +#include <sysdep-cancel.h>
>>> +
>>> +#if !defined(__NR_preadv64v2) && defined(__NR_preadv2)
>>> +# define __NR_preadv64v2 __NR_preadv2
>>> +#endif
>>> +
>>> +ssize_t
>>> +preadv64v2 (int fd, const struct iovec *vector, int count, off64_t offset,
>>> +	    int flags)
>>> +{
>>> +#ifdef __NR_preadv64v2
>>> +  ssize_t result = SYSCALL_CANCEL (preadv64v2, fd, vector, count,
>>> +				   LO_HI_LONG (offset), flags);
>>> +  if (result >= 0 || errno != ENOSYS)
>>> +    return result;
>>> +#endif
>>> +  /* Trying to emulate the preadv2 syscall flags is troublesome:
>>> +
>>> +     * We can not temporary change the file state of the O_DSYNC and O_SYNC
>>> +       flags to emulate RWF_{D}SYNC (attempts to change the state of using
>>> +       fcntl are silently ignored).
>>> +
>>> +     * IOCB_HIPRI requires the file opened in O_DIRECT and uses an internal
>>> +       semantic not provided by any other flag (O_NONBLOCK for instance).  */
>>> +
>>> +  if (flags != 0)
>>> +    {
>>> +      __set_errno (EOPNOTSUPP);
>>> +      return -1;
>>> +    }
>>> +  return preadv64 (fd, vector, count, offset);
>>> +}
>>> +
>>> +#ifdef __OFF_T_MATCHES_OFF64_T
>>> +strong_alias (preadv64v2, preadv2)
>>> +#endif
>>> diff --git a/sysdeps/unix/sysv/linux/pwrite64.c b/sysdeps/unix/sysv/linux/pwrite64.c
>>> index 57e5d20..71959c0 100644
>>> --- a/sysdeps/unix/sysv/linux/pwrite64.c
>>> +++ b/sysdeps/unix/sysv/linux/pwrite64.c
>>> @@ -28,6 +28,7 @@ __libc_pwrite64 (int fd, const void *buf, size_t count, off64_t offset)
>>>  {
>>>    return SYSCALL_CANCEL (pwrite64, fd, buf, count, SYSCALL_LL64_PRW (offset));
>>>  }
>>> +
>>>  weak_alias (__libc_pwrite64, __pwrite64)
>>>  libc_hidden_weak (__pwrite64)
>>>  weak_alias (__libc_pwrite64, pwrite64)
>>> diff --git a/sysdeps/unix/sysv/linux/pwritev.c b/sysdeps/unix/sysv/linux/pwritev.c
>>> index ce02996..7545cb3 100644
>>> --- a/sysdeps/unix/sysv/linux/pwritev.c
>>> +++ b/sysdeps/unix/sysv/linux/pwritev.c
>>> @@ -50,4 +50,6 @@ pwritev (int fd, const struct iovec *vector, int count, off_t offset)
>>>  #  define OFF_T off_t
>>>  #  include <sysdeps/posix/pwritev_common.c>
>>>  # endif /* __ASSUME_PREADV  */
>>> +
>>> +libc_hidden_def (pwritev)
>>>  #endif
>>> diff --git a/sysdeps/unix/sysv/linux/pwritev2.c b/sysdeps/unix/sysv/linux/pwritev2.c
>>> new file mode 100644
>>> index 0000000..72f0471
>>> --- /dev/null
>>> +++ b/sysdeps/unix/sysv/linux/pwritev2.c
>>> @@ -0,0 +1,51 @@
>>> +/* Linux implementation of pwritev2.
>>> +   Copyright (C) 2017 Free Software Foundation, Inc.
>>> +   This file is part of the GNU C Library.
>>> +
>>> +   The GNU C Library is free software; you can redistribute it and/or
>>> +   modify it under the terms of the GNU Lesser General Public
>>> +   License as published by the Free Software Foundation; either
>>> +   version 2.1 of the License, or (at your option) any later version.
>>> +
>>> +   The GNU C Library is distributed in the hope that it will be useful,
>>> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
>>> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>>> +   Lesser General Public License for more details.
>>> +
>>> +   You should have received a copy of the GNU Lesser General Public
>>> +   License along with the GNU C Library; if not, see
>>> +   <http://www.gnu.org/licenses/>.  */
>>> +
>>> +#include <sys/uio.h>
>>> +#include <sysdep-cancel.h>
>>> +
>>> +#ifndef __OFF_T_MATCHES_OFF64_T
>>> +
>>> +ssize_t
>>> +pwritev2 (int fd, const struct iovec *vector, int count, off_t offset,
>>> +	  int flags)
>>> +{
>>> +# ifdef __NR_pwritev2
>>> +  ssize_t result = SYSCALL_CANCEL (pwritev2, fd, vector, count,
>>> +				   LO_HI_LONG (offset), flags);
>>> +  if (result >= 0 || errno != ENOSYS)
>>> +    return result;
>>> +# endif
>>> +  /* Trying to emulate the pwritev2 syscall flags is troublesome:
>>> +
>>> +     * We can not temporary change the file state of the O_DSYNC and O_SYNC
>>> +       flags to emulate RWF_{D}SYNC (attempts to change the state of using
>>> +       fcntl are silently ignored).
>>> +
>>> +     * IOCB_HIPRI requires the file opened in O_DIRECT and uses an internal
>>> +       semantic not provided by any other flag (O_NONBLOCK for instance).  */
>>> +
>>> +  if (flags != 0)
>>> +    {
>>> +      __set_errno (EOPNOTSUPP);
>>> +      return -1;
>>> +    }
>>> +  return pwritev (fd, vector, count, offset);
>>> +}
>>> +
>>> +#endif
>>> diff --git a/sysdeps/unix/sysv/linux/pwritev64.c b/sysdeps/unix/sysv/linux/pwritev64.c
>>> index 45fb90b..9dc4e55 100644
>>> --- a/sysdeps/unix/sysv/linux/pwritev64.c
>>> +++ b/sysdeps/unix/sysv/linux/pwritev64.c
>>> @@ -48,7 +48,9 @@ pwritev64 (int fd, const struct iovec *vector, int count, off64_t offset)
>>>  # define OFF_T off64_t
>>>  # include <sysdeps/posix/pwritev_common.c>
>>>  #endif
>>> +libc_hidden_def (pwritev64)
>>>  
>>>  #ifdef __OFF_T_MATCHES_OFF64_T
>>>  strong_alias (pwritev64, pwritev)
>>> +libc_hidden_def (pwritev)
>>>  #endif
>>> diff --git a/sysdeps/unix/sysv/linux/pwritev64v2.c b/sysdeps/unix/sysv/linux/pwritev64v2.c
>>> new file mode 100644
>>> index 0000000..def9a0b
>>> --- /dev/null
>>> +++ b/sysdeps/unix/sysv/linux/pwritev64v2.c
>>> @@ -0,0 +1,55 @@
>>> +/* Linux implementation of pwritev2 (LFS version).
>>> +   Copyright (C) 2017 Free Software Foundation, Inc.
>>> +   This file is part of the GNU C Library.
>>> +
>>> +   The GNU C Library is free software; you can redistribute it and/or
>>> +   modify it under the terms of the GNU Lesser General Public
>>> +   License as published by the Free Software Foundation; either
>>> +   version 2.1 of the License, or (at your option) any later version.
>>> +
>>> +   The GNU C Library is distributed in the hope that it will be useful,
>>> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
>>> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>>> +   Lesser General Public License for more details.
>>> +
>>> +   You should have received a copy of the GNU Lesser General Public
>>> +   License along with the GNU C Library; if not, see
>>> +   <http://www.gnu.org/licenses/>.  */
>>> +
>>> +#include <sys/uio.h>
>>> +#include <sysdep-cancel.h>
>>> +
>>> +#if !defined(__NR_pwritev64v2) && defined(__NR_pwritev2)
>>> +# define __NR_pwritev64v2 __NR_pwritev2
>>> +#endif
>>> +
>>> +ssize_t
>>> +pwritev64v2 (int fd, const struct iovec *vector, int count, off64_t offset,
>>> +	     int flags)
>>> +{
>>> +#ifdef __NR_pwritev64v2
>>> +  ssize_t result = SYSCALL_CANCEL (pwritev64v2, fd, vector, count,
>>> +				   LO_HI_LONG (offset), flags);
>>> +  if (result >= 0 || errno != ENOSYS)
>>> +    return result;
>>> +#endif
>>> +  /* Trying to emulate the pwritev2 syscall flags is troublesome:
>>> +
>>> +     * We can not temporary change the file state of the O_DSYNC and O_SYNC
>>> +       flags to emulate RWF_{D}SYNC (attempts to change the state of using
>>> +       fcntl are silently ignored).
>>> +
>>> +     * IOCB_HIPRI requires the file opened in O_DIRECT and uses an internal
>>> +       semantic not provided by any other flag (O_NONBLOCK for instance).  */
>>> +
>>> +  if (flags != 0)
>>> +    {
>>> +      __set_errno (EOPNOTSUPP);
>>> +      return -1;
>>> +    }
>>> +  return pwritev64 (fd, vector, count, offset);
>>> +}
>>> +
>>> +#ifdef __OFF_T_MATCHES_OFF64_T
>>> +strong_alias (pwritev64v2, pwritev2)
>>> +#endif
>>> diff --git a/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist b/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
>>> index ed1b6bf..eb9e72f 100644
>>> --- a/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
>>> +++ b/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
>>> @@ -1980,6 +1980,11 @@ GLIBC_2.25 getrandom F
>>>  GLIBC_2.25 strfromd F
>>>  GLIBC_2.25 strfromf F
>>>  GLIBC_2.25 strfroml F
>>> +GLIBC_2.26 GLIBC_2.26 A
>>> +GLIBC_2.26 preadv2 F
>>> +GLIBC_2.26 preadv64v2 F
>>> +GLIBC_2.26 pwritev2 F
>>> +GLIBC_2.26 pwritev64v2 F
>>>  GLIBC_2.3 GLIBC_2.3 A
>>>  GLIBC_2.3 __ctype_b_loc F
>>>  GLIBC_2.3 __ctype_tolower_loc F
>>> diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist b/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
>>> index 2e75d29..1402959 100644
>>> --- a/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
>>> +++ b/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
>>> @@ -1881,6 +1881,11 @@ GLIBC_2.25 getrandom F
>>>  GLIBC_2.25 strfromd F
>>>  GLIBC_2.25 strfromf F
>>>  GLIBC_2.25 strfroml F
>>> +GLIBC_2.26 GLIBC_2.26 A
>>> +GLIBC_2.26 preadv2 F
>>> +GLIBC_2.26 preadv64v2 F
>>> +GLIBC_2.26 pwritev2 F
>>> +GLIBC_2.26 pwritev64v2 F
>>>  GLIBC_2.3 GLIBC_2.3 A
>>>  GLIBC_2.3 __ctype_b_loc F
>>>  GLIBC_2.3 __ctype_tolower_loc F
>>> diff --git a/sysdeps/unix/sysv/linux/sh/libc.abilist b/sysdeps/unix/sysv/linux/sh/libc.abilist
>>> index bd74c0c..e9eefcb 100644
>>> --- a/sysdeps/unix/sysv/linux/sh/libc.abilist
>>> +++ b/sysdeps/unix/sysv/linux/sh/libc.abilist
>>> @@ -1866,6 +1866,11 @@ GLIBC_2.25 getrandom F
>>>  GLIBC_2.25 strfromd F
>>>  GLIBC_2.25 strfromf F
>>>  GLIBC_2.25 strfroml F
>>> +GLIBC_2.26 GLIBC_2.26 A
>>> +GLIBC_2.26 preadv2 F
>>> +GLIBC_2.26 preadv64v2 F
>>> +GLIBC_2.26 pwritev2 F
>>> +GLIBC_2.26 pwritev64v2 F
>>>  GLIBC_2.3 GLIBC_2.3 A
>>>  GLIBC_2.3 __ctype_b_loc F
>>>  GLIBC_2.3 __ctype_tolower_loc F
>>> diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist b/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
>>> index 5584838..967699e 100644
>>> --- a/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
>>> +++ b/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
>>> @@ -1972,6 +1972,11 @@ GLIBC_2.25 getrandom F
>>>  GLIBC_2.25 strfromd F
>>>  GLIBC_2.25 strfromf F
>>>  GLIBC_2.25 strfroml F
>>> +GLIBC_2.26 GLIBC_2.26 A
>>> +GLIBC_2.26 preadv2 F
>>> +GLIBC_2.26 preadv64v2 F
>>> +GLIBC_2.26 pwritev2 F
>>> +GLIBC_2.26 pwritev64v2 F
>>>  GLIBC_2.3 GLIBC_2.3 A
>>>  GLIBC_2.3 __ctype_b_loc F
>>>  GLIBC_2.3 __ctype_tolower_loc F
>>> diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist b/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
>>> index efedbe2..9dd938a 100644
>>> --- a/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
>>> +++ b/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
>>> @@ -1910,6 +1910,11 @@ GLIBC_2.25 getrandom F
>>>  GLIBC_2.25 strfromd F
>>>  GLIBC_2.25 strfromf F
>>>  GLIBC_2.25 strfroml F
>>> +GLIBC_2.26 GLIBC_2.26 A
>>> +GLIBC_2.26 preadv2 F
>>> +GLIBC_2.26 preadv64v2 F
>>> +GLIBC_2.26 pwritev2 F
>>> +GLIBC_2.26 pwritev64v2 F
>>>  GLIBC_2.3 GLIBC_2.3 A
>>>  GLIBC_2.3 __ctype_b_loc F
>>>  GLIBC_2.3 __ctype_tolower_loc F
>>> diff --git a/sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist b/sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist
>>> index ffd988a..68c9887 100644
>>> --- a/sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist
>>> +++ b/sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist
>>> @@ -2104,3 +2104,8 @@ GLIBC_2.25 getrandom F
>>>  GLIBC_2.25 strfromd F
>>>  GLIBC_2.25 strfromf F
>>>  GLIBC_2.25 strfroml F
>>> +GLIBC_2.26 GLIBC_2.26 A
>>> +GLIBC_2.26 preadv2 F
>>> +GLIBC_2.26 preadv64v2 F
>>> +GLIBC_2.26 pwritev2 F
>>> +GLIBC_2.26 pwritev64v2 F
>>> diff --git a/sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist b/sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist
>>> index f0c13ce..97aa0f7 100644
>>> --- a/sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist
>>> +++ b/sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist
>>> @@ -2104,3 +2104,8 @@ GLIBC_2.25 getrandom F
>>>  GLIBC_2.25 strfromd F
>>>  GLIBC_2.25 strfromf F
>>>  GLIBC_2.25 strfroml F
>>> +GLIBC_2.26 GLIBC_2.26 A
>>> +GLIBC_2.26 preadv2 F
>>> +GLIBC_2.26 preadv64v2 F
>>> +GLIBC_2.26 pwritev2 F
>>> +GLIBC_2.26 pwritev64v2 F
>>> diff --git a/sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist b/sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist
>>> index ffd988a..68c9887 100644
>>> --- a/sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist
>>> +++ b/sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist
>>> @@ -2104,3 +2104,8 @@ GLIBC_2.25 getrandom F
>>>  GLIBC_2.25 strfromd F
>>>  GLIBC_2.25 strfromf F
>>>  GLIBC_2.25 strfroml F
>>> +GLIBC_2.26 GLIBC_2.26 A
>>> +GLIBC_2.26 preadv2 F
>>> +GLIBC_2.26 preadv64v2 F
>>> +GLIBC_2.26 pwritev2 F
>>> +GLIBC_2.26 pwritev64v2 F
>>> diff --git a/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist b/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
>>> index f57004c..2032659 100644
>>> --- a/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
>>> +++ b/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
>>> @@ -1861,6 +1861,11 @@ GLIBC_2.25 getrandom F
>>>  GLIBC_2.25 strfromd F
>>>  GLIBC_2.25 strfromf F
>>>  GLIBC_2.25 strfroml F
>>> +GLIBC_2.26 GLIBC_2.26 A
>>> +GLIBC_2.26 preadv2 F
>>> +GLIBC_2.26 preadv64v2 F
>>> +GLIBC_2.26 pwritev2 F
>>> +GLIBC_2.26 pwritev64v2 F
>>>  GLIBC_2.3 GLIBC_2.3 A
>>>  GLIBC_2.3 __ctype_b_loc F
>>>  GLIBC_2.3 __ctype_tolower_loc F
>>> diff --git a/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist b/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
>>> index 05629e1..11a278c 100644
>>> --- a/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
>>> +++ b/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
>>> @@ -2104,3 +2104,8 @@ GLIBC_2.25 getrandom F
>>>  GLIBC_2.25 strfromd F
>>>  GLIBC_2.25 strfromf F
>>>  GLIBC_2.25 strfroml F
>>> +GLIBC_2.26 GLIBC_2.26 A
>>> +GLIBC_2.26 preadv2 F
>>> +GLIBC_2.26 preadv64v2 F
>>> +GLIBC_2.26 pwritev2 F
>>> +GLIBC_2.26 pwritev64v2 F
>>>
Siddhesh Poyarekar June 1, 2017, 4:40 p.m. UTC | #4
On Thursday 04 May 2017 06:13 PM, Adhemerval Zanella wrote:
> 	* nptl/tst-cancel4.c (tf_pwritev2): New test.
> 	(tf_preadv2): Likewise.

These tests are failing for tst-cancelx4 and tst-cancelx5 on the aarch64
buildbot:


tst-cancelx4.out:

cleanup handler not called for 'preadv2'
cleanup handler not called for 'pwritev2'

tst-cancelx5.out:

cleanup handler not called for 'preadv2'
cleanup handler not called for 'pwritev2'

Siddhesh
Adhemerval Zanella June 1, 2017, 6:14 p.m. UTC | #5
On 01/06/2017 13:40, Siddhesh Poyarekar wrote:
> On Thursday 04 May 2017 06:13 PM, Adhemerval Zanella wrote:
>> 	* nptl/tst-cancel4.c (tf_pwritev2): New test.
>> 	(tf_preadv2): Likewise.
> 
> These tests are failing for tst-cancelx4 and tst-cancelx5 on the aarch64
> buildbot:
> 
> 
> tst-cancelx4.out:
> 
> cleanup handler not called for 'preadv2'
> cleanup handler not called for 'pwritev2'
> 
> tst-cancelx5.out:
> 
> cleanup handler not called for 'preadv2'
> cleanup handler not called for 'pwritev2'
> 
> Siddhesh
> 

I am trying to figure out why this is failing on the bot, I can't reproduce
it on my aarch64 box (linux 3.19.0-33-generic, gcc 4.9.2).  I also check on
x86_64 with and without p{read,write}v2 support (kernel 4.4.0 and
kernel 4.10).  I will try check on a aarc64 with 4.6 kernel.
H.J. Lu June 2, 2017, 1 p.m. UTC | #6
On Thu, Jun 1, 2017 at 11:14 AM, Adhemerval Zanella
<adhemerval.zanella@linaro.org> wrote:
> On 01/06/2017 13:40, Siddhesh Poyarekar wrote:
>> On Thursday 04 May 2017 06:13 PM, Adhemerval Zanella wrote:
>>>      * nptl/tst-cancel4.c (tf_pwritev2): New test.
>>>      (tf_preadv2): Likewise.
>>
>> These tests are failing for tst-cancelx4 and tst-cancelx5 on the aarch64
>> buildbot:
>>
>>
>> tst-cancelx4.out:
>>
>> cleanup handler not called for 'preadv2'
>> cleanup handler not called for 'pwritev2'
>>
>> tst-cancelx5.out:
>>
>> cleanup handler not called for 'preadv2'
>> cleanup handler not called for 'pwritev2'
>>
>> Siddhesh
>>
>
> I am trying to figure out why this is failing on the bot, I can't reproduce
> it on my aarch64 box (linux 3.19.0-33-generic, gcc 4.9.2).  I also check on
> x86_64 with and without p{read,write}v2 support (kernel 4.4.0 and
> kernel 4.10).  I will try check on a aarc64 with 4.6 kernel.

I got

[hjl@gnu-tools-1 build-x86_64-linux]$ ./misc/tst-preadvwritev2
error: tst-preadvwritev-common.c:74: first pwritev returned -1
error: 1 test failures
[hjl@gnu-tools-1 build-x86_64-linux]$

on one of my x86-64 machines.  But when I ran it under gdb, it passed.
Tulio Magno Quites Machado Filho June 2, 2017, 1:02 p.m. UTC | #7
Adhemerval Zanella <adhemerval.zanella@linaro.org> writes:

> On 01/06/2017 13:40, Siddhesh Poyarekar wrote:
>> On Thursday 04 May 2017 06:13 PM, Adhemerval Zanella wrote:
>>> 	* nptl/tst-cancel4.c (tf_pwritev2): New test.
>>> 	(tf_preadv2): Likewise.
>> 
>> These tests are failing for tst-cancelx4 and tst-cancelx5 on the aarch64
>> buildbot:
>> 
>> 
>> tst-cancelx4.out:
>> 
>> cleanup handler not called for 'preadv2'
>> cleanup handler not called for 'pwritev2'
>> 
>> tst-cancelx5.out:
>> 
>> cleanup handler not called for 'preadv2'
>> cleanup handler not called for 'pwritev2'
>> 
>> Siddhesh
>> 
>
> I am trying to figure out why this is failing on the bot, I can't reproduce
> it on my aarch64 box (linux 3.19.0-33-generic, gcc 4.9.2).  I also check on
> x86_64 with and without p{read,write}v2 support (kernel 4.4.0 and
> kernel 4.10).  I will try check on a aarc64 with 4.6 kernel.

I can reproduce the same error on ppc64 and ppc64le with Linux 4.4 and 4.10.
Zack Weinberg June 2, 2017, 1:04 p.m. UTC | #8
On Fri, Jun 2, 2017 at 9:00 AM, H.J. Lu <hjl.tools@gmail.com> wrote:
>
> I got
>
> [hjl@gnu-tools-1 build-x86_64-linux]$ ./misc/tst-preadvwritev2
> error: tst-preadvwritev-common.c:74: first pwritev returned -1
> error: 1 test failures
> [hjl@gnu-tools-1 build-x86_64-linux]$
>
> on one of my x86-64 machines.  But when I ran it under gdb, it passed.

I see this as well, for both tst-preadvwritev2 and
tst-preadvwritev64v2 on my x86-64 machine (kernel 4.9).  Like HJ, if I
run the test manually, it succeeds.

(And apart for everything else, that error message needs to be fixed
to print strerror(errno).)

zw
Florian Weimer June 2, 2017, 1:34 p.m. UTC | #9
On 06/02/2017 03:04 PM, Zack Weinberg wrote:
> I see this as well, for both tst-preadvwritev2 and
> tst-preadvwritev64v2 on my x86-64 machine (kernel 4.9).  Like HJ, if I
> run the test manually, it succeeds.

I see this on x86-64.

pwritev2(3,
[{iov_base="\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360",
iov_len=32},
{iov_base="\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17"...,
iov_len=64}], 2, 0, 0x30 /* RWF_??? */) = -1 EOPNOTSUPP (Operation not
supported)

On a kernel which supports pwritev2 in general.  I do not know yet where
the 0x30 comes from.

Florian
Adhemerval Zanella June 2, 2017, 2:04 p.m. UTC | #10
On 02/06/2017 10:02, Tulio Magno Quites Machado Filho wrote:
> Adhemerval Zanella <adhemerval.zanella@linaro.org> writes:
> 
>> On 01/06/2017 13:40, Siddhesh Poyarekar wrote:
>>> On Thursday 04 May 2017 06:13 PM, Adhemerval Zanella wrote:
>>>> 	* nptl/tst-cancel4.c (tf_pwritev2): New test.
>>>> 	(tf_preadv2): Likewise.
>>>
>>> These tests are failing for tst-cancelx4 and tst-cancelx5 on the aarch64
>>> buildbot:
>>>
>>>
>>> tst-cancelx4.out:
>>>
>>> cleanup handler not called for 'preadv2'
>>> cleanup handler not called for 'pwritev2'
>>>
>>> tst-cancelx5.out:
>>>
>>> cleanup handler not called for 'preadv2'
>>> cleanup handler not called for 'pwritev2'
>>>
>>> Siddhesh
>>>
>>
>> I am trying to figure out why this is failing on the bot, I can't reproduce
>> it on my aarch64 box (linux 3.19.0-33-generic, gcc 4.9.2).  I also check on
>> x86_64 with and without p{read,write}v2 support (kernel 4.4.0 and
>> kernel 4.10).  I will try check on a aarc64 with 4.6 kernel.
> 
> I can reproduce the same error on ppc64 and ppc64le with Linux 4.4 and 4.10.
> 

The cancellation issue is the missing build flags to make cancellation 
work correctly on some architectures (-fexceptions -fasynchronous-unwind-tables).
It fixed the issue in ppc64le environment I have access.  I will push this
upstream.
Adhemerval Zanella June 2, 2017, 2:07 p.m. UTC | #11
On 02/06/2017 10:34, Florian Weimer wrote:
> On 06/02/2017 03:04 PM, Zack Weinberg wrote:
>> I see this as well, for both tst-preadvwritev2 and
>> tst-preadvwritev64v2 on my x86-64 machine (kernel 4.9).  Like HJ, if I
>> run the test manually, it succeeds.
> 
> I see this on x86-64.
> 
> pwritev2(3,
> [{iov_base="\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360",
> iov_len=32},
> {iov_base="\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17"...,
> iov_len=64}], 2, 0, 0x30 /* RWF_??? */) = -1 EOPNOTSUPP (Operation not
> supported)
> 
> On a kernel which supports pwritev2 in general.  I do not know yet where
> the 0x30 comes from.
> 
> Florian
> 

This one still puzzles me, on 4.10.0 with gcc 6.3.0 I am seeing:

[...]
[pid 28447] setpgid(0, 0)               = 0
[pid 28447] pwritev2(3, [{"\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360", 32}, {"\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17"..., 64}], 2, 0, 0) = 96
[pid 28447] pwritev2(3, [{"\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360", 32}, {"\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17"..., 64}], 2, 96, 0) = 96
[pid 28447] preadv2(3, [{"\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360", 32}, {"\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17"..., 64}], 2, 0, 0) = 96
[pid 28447] preadv2(3, [{"\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360", 32}, {"\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17"..., 64}], 2, 96, 0) = 96
[pid 28447] getpid()                    = 28447
[...]

This only issue I can think of is something very fuzzy in test build or a miscompilation.
Zack Weinberg June 2, 2017, 2:22 p.m. UTC | #12
On Fri, Jun 2, 2017 at 10:07 AM, Adhemerval Zanella
<adhemerval.zanella@linaro.org> wrote:
>
>
> On 02/06/2017 10:34, Florian Weimer wrote:
>> On 06/02/2017 03:04 PM, Zack Weinberg wrote:
>>> I see this as well, for both tst-preadvwritev2 and
>>> tst-preadvwritev64v2 on my x86-64 machine (kernel 4.9).  Like HJ, if I
>>> run the test manually, it succeeds.
>>
>> I see this on x86-64.
>>
>> pwritev2(3,
>> [{iov_base="\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360",
>> iov_len=32},
>> {iov_base="\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17"...,
>> iov_len=64}], 2, 0, 0x30 /* RWF_??? */) = -1 EOPNOTSUPP (Operation not
>> supported)
>>
>> On a kernel which supports pwritev2 in general.  I do not know yet where
>> the 0x30 comes from.
>>
>> Florian
>>
>
> This one still puzzles me, on 4.10.0 with gcc 6.3.0 I am seeing:
>
> [...]
> [pid 28447] setpgid(0, 0)               = 0
> [pid 28447] pwritev2(3, [{"\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360", 32}, {"\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17"..., 64}], 2, 0, 0) = 96
> [pid 28447] pwritev2(3, [{"\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360", 32}, {"\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17"..., 64}], 2, 96, 0) = 96
> [pid 28447] preadv2(3, [{"\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360", 32}, {"\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17"..., 64}], 2, 0, 0) = 96
> [pid 28447] preadv2(3, [{"\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360", 32}, {"\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17"..., 64}], 2, 96, 0) = 96
> [pid 28447] getpid()                    = 28447
> [...]
>
> This only issue I can think of is something very fuzzy in test build or a miscompilation.

There's gotta be something wonky with the argument passing. Maybe try
running the test case under valgrind?  Also this trick often helps
when a failure goes away when you run it manually:

export CHANGE_SIZE_OF_ENV=""
while
    the-command-that-should-fail
do
    CHANGE_SIZE_OF_ENV="${CHANGE_SIZE_OF_ENV}x"
    echo -n .
done; echo

zw
Adhemerval Zanella June 2, 2017, 6:19 p.m. UTC | #13
On 02/06/2017 11:22, Zack Weinberg wrote:
> On Fri, Jun 2, 2017 at 10:07 AM, Adhemerval Zanella
> <adhemerval.zanella@linaro.org> wrote:
>>
>>
>> On 02/06/2017 10:34, Florian Weimer wrote:
>>> On 06/02/2017 03:04 PM, Zack Weinberg wrote:
>>>> I see this as well, for both tst-preadvwritev2 and
>>>> tst-preadvwritev64v2 on my x86-64 machine (kernel 4.9).  Like HJ, if I
>>>> run the test manually, it succeeds.
>>>
>>> I see this on x86-64.
>>>
>>> pwritev2(3,
>>> [{iov_base="\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360",
>>> iov_len=32},
>>> {iov_base="\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17"...,
>>> iov_len=64}], 2, 0, 0x30 /* RWF_??? */) = -1 EOPNOTSUPP (Operation not
>>> supported)
>>>
>>> On a kernel which supports pwritev2 in general.  I do not know yet where
>>> the 0x30 comes from.
>>>
>>> Florian
>>>
>>
>> This one still puzzles me, on 4.10.0 with gcc 6.3.0 I am seeing:
>>
>> [...]
>> [pid 28447] setpgid(0, 0)               = 0
>> [pid 28447] pwritev2(3, [{"\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360", 32}, {"\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17"..., 64}], 2, 0, 0) = 96
>> [pid 28447] pwritev2(3, [{"\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360", 32}, {"\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17"..., 64}], 2, 96, 0) = 96
>> [pid 28447] preadv2(3, [{"\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360", 32}, {"\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17"..., 64}], 2, 0, 0) = 96
>> [pid 28447] preadv2(3, [{"\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360\360", 32}, {"\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17\17"..., 64}], 2, 96, 0) = 96
>> [pid 28447] getpid()                    = 28447
>> [...]
>>
>> This only issue I can think of is something very fuzzy in test build or a miscompilation.
> 
> There's gotta be something wonky with the argument passing. Maybe try
> running the test case under valgrind?  Also this trick often helps
> when a failure goes away when you run it manually:
> 
> export CHANGE_SIZE_OF_ENV=""
> while
>     the-command-that-should-fail
> do
>     CHANGE_SIZE_OF_ENV="${CHANGE_SIZE_OF_ENV}x"
>     echo -n .
> done; echo
> 
> zw
> 

I am even more confident this is indeed a miscompilation from GCC7 branch.
Using a previous built x86_64-linux-gnu with GCC6 branch I saw no issue, however
using GCC7 there is indeed the test failure.  And it seems to show only for kernels
with support for p{read,write}v2 syscall, which means it stress the default
SYSCALL_CANCEL path.

However, running a GCC6 built testcase with a GCC7 build glibc (with testrun.sh)
I saw no issue.  The GCC7 built test also fails with a GCC6 built glibc.  I will
check with GCC master to see if this is something only on GCC7 branch or if it
is still on master.

Also, I seems that for GCC7 only x86_64-linux-gnu is affect on x86.
Florian Weimer June 2, 2017, 7:02 p.m. UTC | #14
On 06/02/2017 08:19 PM, Adhemerval Zanella wrote:
> I am even more confident this is indeed a miscompilation from GCC7 branch.
> Using a previous built x86_64-linux-gnu with GCC6 branch I saw no issue, however
> using GCC7 there is indeed the test failure.  And it seems to show only for kernels
> with support for p{read,write}v2 syscall, which means it stress the default
> SYSCALL_CANCEL path.
> 
> However, running a GCC6 built testcase with a GCC7 build glibc (with testrun.sh)
> I saw no issue.  The GCC7 built test also fails with a GCC6 built glibc.  I will
> check with GCC master to see if this is something only on GCC7 branch or if it
> is still on master.
> 
> Also, I seems that for GCC7 only x86_64-linux-gnu is affect on x86.

I see it with GCC 6.3 on Fedora 24, x86-64 as well.  It could be a
broken GCC 7 patch that was backported, or perhaps our constraints for
the syscall instruction are off.

Florian
Adhemerval Zanella June 2, 2017, 7:46 p.m. UTC | #15
On 02/06/2017 16:02, Florian Weimer wrote:
> On 06/02/2017 08:19 PM, Adhemerval Zanella wrote:
>> I am even more confident this is indeed a miscompilation from GCC7 branch.
>> Using a previous built x86_64-linux-gnu with GCC6 branch I saw no issue, however
>> using GCC7 there is indeed the test failure.  And it seems to show only for kernels
>> with support for p{read,write}v2 syscall, which means it stress the default
>> SYSCALL_CANCEL path.
>>
>> However, running a GCC6 built testcase with a GCC7 build glibc (with testrun.sh)
>> I saw no issue.  The GCC7 built test also fails with a GCC6 built glibc.  I will
>> check with GCC master to see if this is something only on GCC7 branch or if it
>> is still on master.
>>
>> Also, I seems that for GCC7 only x86_64-linux-gnu is affect on x86.
> 
> I see it with GCC 6.3 on Fedora 24, x86-64 as well.  It could be a
> broken GCC 7 patch that was backported, or perhaps our constraints for
> the syscall instruction are off.

My GCC 6.3 was built with build-many-glibcs.py, so I assume it contains
no backports.  I just checked with GCC trunk (gcc version 8.0.0 20170602)
built also with build-many-glibcs.py and it does not trigger the issue.
diff mbox

Patch

diff --git a/NEWS b/NEWS
index 5558ca3..afad4b1 100644
--- a/NEWS
+++ b/NEWS
@@ -57,6 +57,13 @@  Version 2.26
   be added on next major revision of POSIX, so current support is enabled
   with _GNU_SOURCE.
 
+* New preadv2 and pwritev2 are added to libc.  They are Linux extensions to
+  preadv and pwritev with an additional flag argument where it is possible
+  to set high priority or use O_DSYNC or O_SYNC for an specific IO operation.
+  For complete support it requires Linux kernel version 4.6, otherwise a
+  compat implementation will be used (which refuses all flags and routes it
+  to preadv or pwritev).
+
 Security related changes:
 
 * The DNS stub resolver limits the advertised UDP buffer size to 1200 bytes,
diff --git a/include/sys/uio.h b/include/sys/uio.h
index f44ce18..20860bf 100644
--- a/include/sys/uio.h
+++ b/include/sys/uio.h
@@ -7,5 +7,11 @@  extern ssize_t __readv (int __fd, const struct iovec *__iovec,
 			int __count);
 extern ssize_t __writev (int __fd, const struct iovec *__iovec,
 			 int __count);
+
+/* Used for p{read,write}{v64}v2 implementation.  */
+libc_hidden_proto (preadv)
+libc_hidden_proto (preadv64)
+libc_hidden_proto (pwritev)
+libc_hidden_proto (pwritev64)
 #endif
 #endif
diff --git a/manual/llio.texi b/manual/llio.texi
index dae3754..404a966 100644
--- a/manual/llio.texi
+++ b/manual/llio.texi
@@ -756,6 +756,115 @@  When the source file is compiled using @code{_FILE_OFFSET_BITS == 64} on a
 @code{pwritev} and so transparently replaces the 32 bit interface.
 @end deftypefun
 
+@comment sys/uio.h
+@comment GNU
+@deftypefun ssize_t preadv2 (int @var{fd}, const struct iovec *@var{iov}, int @var{iovcnt}, off_t @var{offset}, int @var{flags})
+@safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}}
+@c This is a syscall for Linux v4.6.  The sysdeps/posix fallback emulation
+@c is also MT-Safe since it calls preadv.
+
+This function is similar to the @code{preadv} function, with the difference
+it adds an extra @var{flags} parameter of type @code{int}.  The supported
+@var{flags} are dependent of the underlying system.  For Linux it supports:
+
+@vtable @code
+@item RWF_HIPRI
+High priority request.  This adds a flag that tells the file system that
+this is a high priority request for which it is worth to poll the hardware.
+The flag is purely advisory and can be ignored if not supported.  The
+@var{fd} must be opened using @code{O_DIRECT}.
+
+@item RWF_DSYNC
+Per-IO synchronization as if the file was opened with @code{O_DSYNC} flag.
+
+@item RWF_SYNC
+Per-IO synchronization as if the file was opened with @code{O_SYNC} flag.
+@end vtable
+
+When the source file is compiled with @code{_FILE_OFFSET_BITS == 64} the
+@code{preadv2} function is in fact @code{preadv64v2} and the type
+@code{off_t} has 64 bits, which makes it possible to handle files up to
+@twoexp{63} bytes in length.
+
+The return value is a count of bytes (@emph{not} buffers) read, @math{0}
+indicating end-of-file, or @math{-1} indicating an error.  The possible
+errors are the same as in @code{preadv} with the addition of:
+
+@table @code
+
+@item EOPNOTSUPP
+
+@c The default sysdeps/posix code will return it for any flags value
+@c different than 0.
+An unsupported @var{flags} was used.
+
+@end table
+
+@end deftypefun
+
+@comment unistd.h
+@comment GNU
+@deftypefun ssize_t preadv64v2 (int @var{fd}, const struct iovec *@var{iov}, int @var{iovcnt}, off64_t @var{offset}, int @var{flags})
+@safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}}
+@c This is a syscall for Linux v4.6.  The sysdeps/posix fallback emulation
+@c is also MT-Safe since it calls preadv.
+
+This function is similar to the @code{preadv2} function with the difference
+is that the @var{offset} parameter is of type @code{off64_t} instead of
+@code{off_t}.  It makes it possible on 32 bit machines to address
+files larger than @twoexp{31} bytes and up to @twoexp{63} bytes.  The
+file descriptor @code{filedes} must be opened using @code{open64} since
+otherwise the large offsets possible with @code{off64_t} will lead to
+errors with a descriptor in small file mode.
+
+When the source file is compiled using @code{_FILE_OFFSET_BITS == 64} on a
+32 bit machine this function is actually available under the name
+@code{preadv2} and so transparently replaces the 32 bit interface.
+@end deftypefun
+
+
+@comment sys/uio.h
+@comment GNU
+@deftypefun ssize_t pwritev2 (int @var{fd}, const struct iovec *@var{iov}, int @var{iovcnt}, off_t @var{offset}, int @var{flags})
+@safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}}
+@c This is a syscall for Linux v4.6.  The sysdeps/posix fallback emulation
+@c is also MT-Safe since it calls pwritev.
+
+This function is similar to the @code{pwritev} function, with the difference
+it adds an extra @var{flags} parameter of type @code{int}.  The supported
+@var{flags} are dependent of the underlying system and for Linux it supports
+the same ones as for @code{preadv2}.
+
+When the source file is compiled with @code{_FILE_OFFSET_BITS == 64} the
+@code{pwritev2} function is in fact @code{pwritev64v2} and the type
+@code{off_t} has 64 bits, which makes it possible to handle files up to
+@twoexp{63} bytes in length.
+
+The return value is a count of bytes (@emph{not} buffers) write, @math{0}
+indicating end-of-file, or @math{-1} indicating an error.  The possible
+errors are the same as in @code{preadv2}.
+@end deftypefun
+
+@comment unistd.h
+@comment GNU
+@deftypefun ssize_t pwritev64v2 (int @var{fd}, const struct iovec *@var{iov}, int @var{iovcnt}, off64_t @var{offset}, int @var{flags})
+@safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}}
+@c This is a syscall for Linux v4.6.  The sysdeps/posix fallback emulation
+@c is also MT-Safe since it calls pwritev.
+
+This function is similar to the @code{pwritev2} function with the difference
+is that the @var{offset} parameter is of type @code{off64_t} instead of
+@code{off_t}.  It makes it possible on 32 bit machines to address
+files larger than @twoexp{31} bytes and up to @twoexp{63} bytes.  The
+file descriptor @code{filedes} must be opened using @code{open64} since
+otherwise the large offsets possible with @code{off64_t} will lead to
+errors with a descriptor in small file mode.
+
+When the source file is compiled using @code{_FILE_OFFSET_BITS == 64} on a
+32 bit machine this function is actually available under the name
+@code{pwritev2} and so transparently replaces the 32 bit interface.
+@end deftypefun
+
 
 @node File Position Primitive
 @section Setting the File Position of a Descriptor
diff --git a/misc/Makefile b/misc/Makefile
index 622da67..bed46d7 100644
--- a/misc/Makefile
+++ b/misc/Makefile
@@ -39,6 +39,7 @@  headers	:= sys/uio.h bits/uio.h sys/ioctl.h bits/ioctls.h bits/ioctl-types.h \
 
 routines := brk sbrk sstk ioctl \
 	    readv writev preadv preadv64 pwritev pwritev64 \
+	    preadv2 preadv64v2 pwritev2 pwritev64v2 \
 	    setreuid setregid \
 	    seteuid setegid \
 	    getpagesize \
@@ -79,7 +80,9 @@  gpl2lgpl := error.c error.h
 tests := tst-dirname tst-tsearch tst-fdset tst-efgcvt tst-mntent tst-hsearch \
 	 tst-error1 tst-pselect tst-insremque tst-mntent2 bug-hsearch1 \
 	 tst-mntent-blank-corrupt tst-mntent-blank-passno bug18240 \
-	 tst-preadvwritev tst-preadvwritev64 tst-makedev tst-empty \
+	 tst-preadvwritev tst-preadvwritev64 tst-preadvwritev2 \
+	 tst-preadvwritev64v2 \
+	 tst-makedev tst-empty \
 	 tst-atomic tst-atomic-long
 tests-static := tst-empty
 
diff --git a/misc/Versions b/misc/Versions
index f2c90ff..bafda78 100644
--- a/misc/Versions
+++ b/misc/Versions
@@ -155,6 +155,9 @@  libc {
   GLIBC_2.25 {
     gnu_dev_major; gnu_dev_minor; gnu_dev_makedev;
   }
+  GLIBC_2.26 {
+    preadv2; preadv64v2; pwritev2; pwritev64v2;
+  }
   GLIBC_PRIVATE {
     __madvise;
     __mktemp;
diff --git a/misc/preadv2.c b/misc/preadv2.c
new file mode 100644
index 0000000..a62dcaa
--- /dev/null
+++ b/misc/preadv2.c
@@ -0,0 +1,30 @@ 
+/* Default implementation of preadv2.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <sys/uio.h>
+
+/* Same as preadv but with an additional flags argument.  */
+ssize_t
+preadv2 (int fd, const struct iovec *vector, int count, off_t offset,
+	 int flags)
+{
+  __set_errno (ENOSYS);
+  return -1;
+}
+
+stub_warning (preadv2)
diff --git a/misc/preadv64v2.c b/misc/preadv64v2.c
new file mode 100644
index 0000000..a802c2f
--- /dev/null
+++ b/misc/preadv64v2.c
@@ -0,0 +1,30 @@ 
+/* Default implementation of preadv2 (LFS version).
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <sys/uio.h>
+
+/* Same as preadv64 but with an addional flag argument.  */
+ssize_t
+preadv64v2 (int fd, const struct iovec *vector, int count, off64_t offset,
+	    int flags)
+{
+  __set_errno (ENOSYS);
+  return -1;
+}
+
+stub_warning (preadv64v2)
diff --git a/misc/pwritev2.c b/misc/pwritev2.c
new file mode 100644
index 0000000..b9e0727
--- /dev/null
+++ b/misc/pwritev2.c
@@ -0,0 +1,30 @@ 
+/* Default implementation of pwritev2.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <sys/uio.h>
+
+/* Same as pwritev but with an additional flags argument.  */
+ssize_t
+pwritev2 (int fd, const struct iovec *vector, int count, off_t offset,
+	  int flags)
+{
+  __set_errno (ENOSYS);
+  return -1;
+}
+
+stub_warning (pwritev2)
diff --git a/misc/pwritev64v2.c b/misc/pwritev64v2.c
new file mode 100644
index 0000000..1f874f0
--- /dev/null
+++ b/misc/pwritev64v2.c
@@ -0,0 +1,30 @@ 
+/* Default implementation of pwritev2 (LFS version).
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <sys/uio.h>
+
+/* Same as preadv64 but with an addional flag argument.  */
+ssize_t
+pwritev64v2 (int fd, const struct iovec *vector, int count, off64_t offset,
+	     int flags)
+{
+  __set_errno (ENOSYS);
+  return -1;
+}
+
+stub_warning (pwritev64v2)
diff --git a/misc/sys/uio.h b/misc/sys/uio.h
index e80f013..66c22f0 100644
--- a/misc/sys/uio.h
+++ b/misc/sys/uio.h
@@ -76,6 +76,7 @@  extern ssize_t preadv (int __fd, const struct iovec *__iovec, int __count,
    __THROW.  */
 extern ssize_t pwritev (int __fd, const struct iovec *__iovec, int __count,
 			__off_t __offset) __wur;
+
 # else
 #  ifdef __REDIRECT
 extern ssize_t __REDIRECT (preadv, (int __fd, const struct iovec *__iovec,
@@ -117,6 +118,46 @@  extern ssize_t pwritev64 (int __fd, const struct iovec *__iovec, int __count,
 # endif
 #endif	/* Use misc.  */
 
+
+#ifdef __USE_GNU
+# ifndef __USE_FILE_OFFSET64
+/* Same as preadv but with an additional flag argumenti defined at uio.h.  */
+extern ssize_t preadv2 (int __fp, const struct iovec *__iovec, int __count,
+			__off_t __offset, int ___flags) __wur;
+
+/* Same as preadv but with an additional flag argument defined at uio.h.  */
+extern ssize_t pwritev2 (int __fd, const struct iovec *__iodev, int __count,
+			 __off_t __offset, int __flags) __wur;
+
+# else
+#  ifdef __REDIRECT
+extern ssize_t __REDIRECT (pwritev2, (int __fd, const struct iovec *__iovec,
+				      int __count, __off64_t __offset,
+				      int __flags),
+			   pwritev64v2) __wur;
+extern ssize_t __REDIRECT (preadv2, (int __fd, const struct iovec *__iovec,
+				     int __count, __off64_t __offset,
+				     int __flags),
+			   preadv64v2) __wur;
+#  else
+#   define preadv2 preadv64v2
+#   define pwritev2 pwritev64v2
+#  endif
+# endif
+
+# ifdef __USE_LARGEFILE64
+/* Same as preadv but with an additional flag argumenti defined at uio.h.  */
+extern ssize_t preadv64v2 (int __fp, const struct iovec *__iovec,
+			   int __count, __off64_t __offset,
+			   int ___flags) __wur;
+
+/* Same as preadv but with an additional flag argument defined at uio.h.  */
+extern ssize_t pwritev64v2 (int __fd, const struct iovec *__iodev,
+			    int __count, __off64_t __offset,
+			    int __flags) __wur;
+# endif
+#endif /* Use GNU.  */
+
 __END_DECLS
 
 #endif /* sys/uio.h */
diff --git a/misc/tst-preadvwritev-common.c b/misc/tst-preadvwritev-common.c
index 5540dfb..676d495 100644
--- a/misc/tst-preadvwritev-common.c
+++ b/misc/tst-preadvwritev-common.c
@@ -18,6 +18,7 @@ 
 
 #include <stdio.h>
 #include <stdint.h>
+#include <errno.h>
 #include <string.h>
 #include <sys/uio.h>
 #include <sys/stat.h>
@@ -39,6 +40,16 @@  do_prepare (int argc, char **argv)
 }
 #define PREPARE do_prepare
 
+#ifndef PREADV
+# define PREADV(__fd, __iov, __iovcnt, __offset) \
+  preadv (__fd, __iov, __iovcnt, __offset)
+#endif
+
+#ifndef PWRITEV
+# define PWRITEV(__fd, __iov, __iovcnt, __offset) \
+  pwritev (__fd, __iov, __iovcnt, __offset)
+#endif
+
 static int
 do_test_with_offset (off_t offset)
 {
@@ -58,13 +69,13 @@  do_test_with_offset (off_t offset)
   iov[1].iov_base = buf2;
   iov[1].iov_len = sizeof buf2;
 
-  ret = pwritev (temp_fd, iov, 2, offset);
+  ret = PWRITEV (temp_fd, iov, 2, offset);
   if (ret == -1)
     FAIL_RET ("first pwritev returned -1");
   if (ret != (sizeof buf1 + sizeof buf2))
     FAIL_RET ("first pwritev returned an unexpected value");
 
-  ret = pwritev (temp_fd, iov, 2, sizeof buf1 + sizeof buf2 + offset);
+  ret = PWRITEV (temp_fd, iov, 2, sizeof buf1 + sizeof buf2 + offset);
   if (ret == -1)
     FAIL_RET ("second pwritev returned -1");
   if (ret != (sizeof buf1 + sizeof buf2))
@@ -82,7 +93,7 @@  do_test_with_offset (off_t offset)
   iov[1].iov_len = sizeof buf4;
 
   /* Now read two buffer with 32 and 64 bytes respectively.  */
-  ret = preadv (temp_fd, iov, 2, offset);
+  ret = PREADV (temp_fd, iov, 2, offset);
   if (ret == -1)
     FAIL_RET ("first preadv returned -1");
   if (ret != (sizeof buf3 + sizeof buf4))
@@ -93,7 +104,7 @@  do_test_with_offset (off_t offset)
   if (memcmp (buf2, buf4, sizeof buf2) != 0)
     FAIL_RET ("second buffer from first preadv different than expected");
 
-  ret = preadv (temp_fd, iov, 2, sizeof buf3 + sizeof buf4 + offset);
+  ret = PREADV (temp_fd, iov, 2, sizeof buf3 + sizeof buf4 + offset);
   if (ret == -1)
     FAIL_RET ("second preadv returned -1");
   if (ret != (sizeof buf3 + sizeof buf4))
diff --git a/misc/tst-preadvwritev2.c b/misc/tst-preadvwritev2.c
new file mode 100644
index 0000000..cf36272
--- /dev/null
+++ b/misc/tst-preadvwritev2.c
@@ -0,0 +1,31 @@ 
+/* Tests for preadv2 and pwritev2.
+   Copyright (C) 2016-2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#define PREADV(__fd, __iov, __iovcnt, __offset) \
+  preadv2 (__fd, __iov, __iovcnt, __offset, 0)
+
+#define PWRITEV(__fd, __iov, __iovcnt, __offset) \
+  pwritev2 (__fd, __iov, __iovcnt, __offset, 0)
+
+#include "tst-preadvwritev-common.c"
+
+static int
+do_test (void)
+{
+  return do_test_with_offset (0);
+}
diff --git a/misc/tst-preadvwritev64v2.c b/misc/tst-preadvwritev64v2.c
new file mode 100644
index 0000000..8d0c48e
--- /dev/null
+++ b/misc/tst-preadvwritev64v2.c
@@ -0,0 +1,33 @@ 
+/* Tests for preadv2 and pwritev2 (LFS version).
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#define _FILE_OFFSET_BITS 64
+
+#define PREADV(__fd, __iov, __iovcnt, __offset) \
+  preadv2 (__fd, __iov, __iovcnt, __offset, 0)
+
+#define PWRITEV(__fd, __iov, __iovcnt, __offset) \
+  pwritev2 (__fd, __iov, __iovcnt, __offset, 0)
+
+#include "tst-preadvwritev-common.c"
+
+static int
+do_test (void)
+{
+  return do_test_with_offset (0);
+}
diff --git a/nptl/tst-cancel4.c b/nptl/tst-cancel4.c
index e66961f..7a560a1 100644
--- a/nptl/tst-cancel4.c
+++ b/nptl/tst-cancel4.c
@@ -1079,6 +1079,75 @@  tf_pwritev (void *arg)
 }
 
 static void *
+tf_pwritev2 (void *arg)
+{
+  int fd;
+
+  if (arg == NULL)
+    /* XXX If somebody can provide a portable test case in which pwritev2
+       blocks we can enable this test to run in both rounds.  */
+    abort ();
+
+  errno = 0;
+
+  char fname[] = "/tmp/tst-cancel4-fd-XXXXXX";
+  tempfd = fd = mkstemp (fname);
+  if (fd == -1)
+    FAIL_EXIT1 ("mkstemp: %m");
+  unlink (fname);
+
+  xpthread_barrier_wait (&b2);
+
+  xpthread_barrier_wait (&b2);
+
+  ssize_t s;
+  pthread_cleanup_push (cl, NULL);
+
+  char buf[WRITE_BUFFER_SIZE];
+  memset (buf, '\0', sizeof (buf));
+  struct iovec iov[1] = { [0] = { .iov_base = buf, .iov_len = sizeof (buf) } };
+  s = pwritev2 (fd, iov, 1, 0, 0);
+
+  pthread_cleanup_pop (0);
+
+  FAIL_EXIT1 ("pwritev2 returns with %zd", s);
+}
+
+static void *
+tf_preadv2 (void *arg)
+{
+  int fd;
+
+  if (arg == NULL)
+    /* XXX If somebody can provide a portable test case in which preadv2
+       blocks we can enable this test to run in both rounds.  */
+    abort ();
+
+  errno = 0;
+
+  char fname[] = "/tmp/tst-cancel4-fd-XXXXXX";
+  tempfd = fd = mkstemp (fname);
+  if (fd == -1)
+    FAIL_EXIT1 ("mkstemp failed: %m");
+  unlink (fname);
+
+  xpthread_barrier_wait (&b2);
+
+  xpthread_barrier_wait (&b2);
+
+  ssize_t s;
+  pthread_cleanup_push (cl, NULL);
+
+  char buf[100];
+  struct iovec iov[1] = { [0] = { .iov_base = buf, .iov_len = sizeof (buf) } };
+  s = preadv2 (fd, iov, 1, 0, 0);
+
+  pthread_cleanup_pop (0);
+
+  FAIL_EXIT1 ("preadv2 returns with %zd", s);
+}
+
+static void *
 tf_fsync (void *arg)
 {
   if (arg == NULL)
@@ -1473,7 +1542,9 @@  struct cancel_tests tests[] =
   ADD_TEST (recvfrom, 2, 0),
   ADD_TEST (recvmsg, 2, 0),
   ADD_TEST (preadv, 2, 1),
+  ADD_TEST (preadv2, 2, 1),
   ADD_TEST (pwritev, 2, 1),
+  ADD_TEST (pwritev2, 2, 1),
   ADD_TEST (open, 2, 1),
   ADD_TEST (close, 2, 1),
   ADD_TEST (pread, 2, 1),
diff --git a/sysdeps/posix/preadv2.c b/sysdeps/posix/preadv2.c
new file mode 100644
index 0000000..2a7cf11
--- /dev/null
+++ b/sysdeps/posix/preadv2.c
@@ -0,0 +1,38 @@ 
+/* Generic version of preadv2.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <unistd.h>
+#include <sys/uio.h>
+
+#ifndef __OFF_T_MATCHES_OFF64_T
+
+/* Since we define no flags for preadv2 just route to preadv.  */
+ssize_t
+preadv2 (int fd, const struct iovec *vector, int count, OFF_T offset,
+	 int flags)
+{
+  if (flags != 0)
+    {
+      __set_errno (EOPNOTSUPP);
+      return -1;
+    }
+
+  return preadv (fd, vector, count, offset);
+}
+
+#endif
diff --git a/sysdeps/posix/preadv64v2.c b/sysdeps/posix/preadv64v2.c
new file mode 100644
index 0000000..e084f3f
--- /dev/null
+++ b/sysdeps/posix/preadv64v2.c
@@ -0,0 +1,37 @@ 
+/* Generic version of preadv2.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <unistd.>
+#include <sys/uio.h>
+
+ssize_t
+preadv64v2 (int fd, const struct iovec *vector, int count, OFF_T offset,
+	    int flags)
+{
+  if (flags != 0)
+    {
+      __set_errno (EOPNOTSUPP);
+      return -1;
+    }
+
+  return preadv64 (fd, vector, count, offset);
+}
+
+#ifdef __OFF_T_MATCHES_OFF64_T
+strong_alias (preadv64v2, preadv2)
+#endif
diff --git a/sysdeps/posix/pwritev2.c b/sysdeps/posix/pwritev2.c
new file mode 100644
index 0000000..5b7650c
--- /dev/null
+++ b/sysdeps/posix/pwritev2.c
@@ -0,0 +1,38 @@ 
+/* Generic version of pwritev2.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <unistd.h>
+#include <sys/uio.h>
+
+#ifndef __OFF_T_MATCHES_OFF64_T
+
+/* Since we define no flags for pwritev2 just route to pwritev.  */
+ssize_t
+pwritev2 (int fd, const struct iovec *vector, int count, OFF_T offset,
+	  int flags)
+{
+  if (flags != 0)
+    {
+      __set_errno (EOPNOTSUPP);
+      return -1;
+    }
+
+  return pwritev (fd, vector, count, offset);
+}
+
+#endif
diff --git a/sysdeps/posix/pwritev64v2.c b/sysdeps/posix/pwritev64v2.c
new file mode 100644
index 0000000..d9727b9
--- /dev/null
+++ b/sysdeps/posix/pwritev64v2.c
@@ -0,0 +1,38 @@ 
+/* Generic version of pwritev2.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <unistd.h>
+#include <sys/uio.h>
+
+/* Since we define no flags for pwritev2 just route to pwritev.  */ 
+ssize_t
+pwritev64v2 (int fd, const struct iovec *vector, int count, OFF_T offset,
+	     int flags)
+{
+  if (flags != 0)
+    {
+      __set_errno (EOPNOTSUPP);
+      return -1;
+    }
+
+  return pwritev64 (fd, vector, count, offset);
+}
+
+#ifdef __OFF_T_MATCHES_OFF64_T
+strong_alias (pwritev64v2, pwritev2)
+#endif
diff --git a/sysdeps/unix/sysv/linux/aarch64/libc.abilist b/sysdeps/unix/sysv/linux/aarch64/libc.abilist
index 58d768c..296f2a5 100644
--- a/sysdeps/unix/sysv/linux/aarch64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/aarch64/libc.abilist
@@ -2097,3 +2097,8 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
diff --git a/sysdeps/unix/sysv/linux/alpha/libc.abilist b/sysdeps/unix/sysv/linux/alpha/libc.abilist
index 906050d..8006e72 100644
--- a/sysdeps/unix/sysv/linux/alpha/libc.abilist
+++ b/sysdeps/unix/sysv/linux/alpha/libc.abilist
@@ -2008,6 +2008,11 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/arm/libc.abilist b/sysdeps/unix/sysv/linux/arm/libc.abilist
index 66112dd..29f9688 100644
--- a/sysdeps/unix/sysv/linux/arm/libc.abilist
+++ b/sysdeps/unix/sysv/linux/arm/libc.abilist
@@ -98,6 +98,11 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
 GLIBC_2.4 GLIBC_2.4 A
 GLIBC_2.4 _Exit F
 GLIBC_2.4 _IO_2_1_stderr_ D 0xa0
diff --git a/sysdeps/unix/sysv/linux/bits/uio.h b/sysdeps/unix/sysv/linux/bits/uio.h
index 1583f04..d5701f8 100644
--- a/sysdeps/unix/sysv/linux/bits/uio.h
+++ b/sysdeps/unix/sysv/linux/bits/uio.h
@@ -69,4 +69,10 @@  extern ssize_t process_vm_writev (pid_t __pid, const struct iovec *__lvec,
 __END_DECLS
 
 # endif
+
+/* Flags for preadv2/pwritev2: */
+#define RWF_HIPRI	0x00000001 /* High priority request.  */
+#define RWF_DSYNC	0x00000002 /* per-IO O_DSYNC.  */
+#define RWF_SYNC	0x00000004 /* per-IO O_SYNC.  */
+
 #endif
diff --git a/sysdeps/unix/sysv/linux/hppa/libc.abilist b/sysdeps/unix/sysv/linux/hppa/libc.abilist
index 3ddadd2..e9cfbaf 100644
--- a/sysdeps/unix/sysv/linux/hppa/libc.abilist
+++ b/sysdeps/unix/sysv/linux/hppa/libc.abilist
@@ -1862,6 +1862,11 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/i386/libc.abilist b/sysdeps/unix/sysv/linux/i386/libc.abilist
index 977ab90..c6ad3c3 100644
--- a/sysdeps/unix/sysv/linux/i386/libc.abilist
+++ b/sysdeps/unix/sysv/linux/i386/libc.abilist
@@ -2020,6 +2020,11 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/ia64/libc.abilist b/sysdeps/unix/sysv/linux/ia64/libc.abilist
index c7edb9a..d0055a2 100644
--- a/sysdeps/unix/sysv/linux/ia64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/ia64/libc.abilist
@@ -1884,6 +1884,11 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/kernel-features.h b/sysdeps/unix/sysv/linux/kernel-features.h
index b981466..8ee1af7 100644
--- a/sysdeps/unix/sysv/linux/kernel-features.h
+++ b/sysdeps/unix/sysv/linux/kernel-features.h
@@ -137,3 +137,8 @@ 
 /* Support for SysV IPC through wired syscalls.  All supported architectures
    either support ipc syscall and/or all the ipc correspondent syscalls.  */
 #define __ASSUME_DIRECT_SYSVIPC_SYSCALLS	1
+
+/* Support for p{read,write}v2 was added in 4.6.  However Linux default
+   implementation does not assume the __ASSUME_* and instead use a fallback
+   implementation based on p{read,write}v and returning an error for
+   non supported flags.  */
diff --git a/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist b/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
index 450be4e..3777676 100644
--- a/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
+++ b/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
@@ -99,6 +99,11 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
 GLIBC_2.4 GLIBC_2.4 A
 GLIBC_2.4 _Exit F
 GLIBC_2.4 _IO_2_1_stderr_ D 0x98
diff --git a/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist b/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
index 9e016bd..8b1f80c 100644
--- a/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
+++ b/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
@@ -1976,6 +1976,11 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/microblaze/libc.abilist b/sysdeps/unix/sysv/linux/microblaze/libc.abilist
index 1a455be..d4db9a8 100644
--- a/sysdeps/unix/sysv/linux/microblaze/libc.abilist
+++ b/sysdeps/unix/sysv/linux/microblaze/libc.abilist
@@ -2097,3 +2097,8 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
diff --git a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
index 8eb5e66..f430bdb 100644
--- a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
@@ -1951,6 +1951,11 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
index 416d9ac..a4dca19 100644
--- a/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
@@ -1949,6 +1949,11 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
index f4949e5..0814fa8 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
@@ -1947,6 +1947,11 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
index c7375ae..a0bdeff 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
@@ -1942,6 +1942,11 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/nios2/libc.abilist b/sysdeps/unix/sysv/linux/nios2/libc.abilist
index 724a0e3..b201290 100644
--- a/sysdeps/unix/sysv/linux/nios2/libc.abilist
+++ b/sysdeps/unix/sysv/linux/nios2/libc.abilist
@@ -2138,3 +2138,8 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
index 2dc32b6..6e7ff24 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
@@ -1980,6 +1980,11 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
index 5658109..19c7c7d 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
@@ -1985,6 +1985,11 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist
index c761221..e94ce38 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist
@@ -2185,3 +2185,8 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist
index 265c769..f3daa33 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist
@@ -99,6 +99,11 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 _Exit F
 GLIBC_2.3 _IO_2_1_stderr_ D 0xe0
diff --git a/sysdeps/unix/sysv/linux/preadv.c b/sysdeps/unix/sysv/linux/preadv.c
index 7d971cc..ecabc8c 100644
--- a/sysdeps/unix/sysv/linux/preadv.c
+++ b/sysdeps/unix/sysv/linux/preadv.c
@@ -50,4 +50,6 @@  preadv (int fd, const struct iovec *vector, int count, off_t offset)
 #  define OFF_T off_t
 #  include <sysdeps/posix/preadv_common.c>
 # endif /* __ASSUME_PREADV  */
+
+libc_hidden_def (preadv)
 #endif
diff --git a/sysdeps/unix/sysv/linux/preadv2.c b/sysdeps/unix/sysv/linux/preadv2.c
new file mode 100644
index 0000000..11fe85e
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/preadv2.c
@@ -0,0 +1,55 @@ 
+/* Linux implementation of preadv2.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <sys/uio.h>
+#include <sysdep-cancel.h>
+
+#ifndef __OFF_T_MATCHES_OFF64_T
+
+# if !defined (__NR_preadv2) && defined (__NR_pread64v2)
+#  define __NR_preadv2 __NR_pread64v2
+# endif
+
+ssize_t
+preadv2 (int fd, const struct iovec *vector, int count, off_t offset,
+	 int flags)
+{
+# ifdef __NR_preadv2
+  ssize_t result = SYSCALL_CANCEL (preadv2, fd, vector, count,
+				   LO_HI_LONG (offset), flags);
+  if (result >= 0 || errno != ENOSYS)
+    return result;
+# endif
+  /* Trying to emulate the preadv2 syscall flags is troublesome:
+
+     * We can not temporary change the file state of the O_DSYNC and O_SYNC
+       flags to emulate RWF_{D}SYNC (attempts to change the state of using
+       fcntl are silently ignored).
+
+     * IOCB_HIPRI requires the file opened in O_DIRECT and uses an internal
+       semantic not provided by any other flag (O_NONBLOCK for instance).  */
+
+  if (flags != 0)
+    {
+      __set_errno (EOPNOTSUPP);
+      return -1;
+    }
+  return preadv (fd, vector, count, offset);
+}
+
+#endif
diff --git a/sysdeps/unix/sysv/linux/preadv64.c b/sysdeps/unix/sysv/linux/preadv64.c
index 66daa74..c96b214 100644
--- a/sysdeps/unix/sysv/linux/preadv64.c
+++ b/sysdeps/unix/sysv/linux/preadv64.c
@@ -48,7 +48,9 @@  preadv64 (int fd, const struct iovec *vector, int count, off64_t offset)
 # define OFF_T off64_t
 # include <sysdeps/posix/preadv_common.c>
 #endif
+libc_hidden_def (preadv64)
 
 #ifdef __OFF_T_MATCHES_OFF64_T
 strong_alias (preadv64, preadv)
+libc_hidden_def (preadv)
 #endif
diff --git a/sysdeps/unix/sysv/linux/preadv64v2.c b/sysdeps/unix/sysv/linux/preadv64v2.c
new file mode 100644
index 0000000..9d7f8c9
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/preadv64v2.c
@@ -0,0 +1,55 @@ 
+/* Linux implementation of preadv2 (LFS version).
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <sys/uio.h>
+#include <sysdep-cancel.h>
+
+#if !defined(__NR_preadv64v2) && defined(__NR_preadv2)
+# define __NR_preadv64v2 __NR_preadv2
+#endif
+
+ssize_t
+preadv64v2 (int fd, const struct iovec *vector, int count, off64_t offset,
+	    int flags)
+{
+#ifdef __NR_preadv64v2
+  ssize_t result = SYSCALL_CANCEL (preadv64v2, fd, vector, count,
+				   LO_HI_LONG (offset), flags);
+  if (result >= 0 || errno != ENOSYS)
+    return result;
+#endif
+  /* Trying to emulate the preadv2 syscall flags is troublesome:
+
+     * We can not temporary change the file state of the O_DSYNC and O_SYNC
+       flags to emulate RWF_{D}SYNC (attempts to change the state of using
+       fcntl are silently ignored).
+
+     * IOCB_HIPRI requires the file opened in O_DIRECT and uses an internal
+       semantic not provided by any other flag (O_NONBLOCK for instance).  */
+
+  if (flags != 0)
+    {
+      __set_errno (EOPNOTSUPP);
+      return -1;
+    }
+  return preadv64 (fd, vector, count, offset);
+}
+
+#ifdef __OFF_T_MATCHES_OFF64_T
+strong_alias (preadv64v2, preadv2)
+#endif
diff --git a/sysdeps/unix/sysv/linux/pwrite64.c b/sysdeps/unix/sysv/linux/pwrite64.c
index 57e5d20..71959c0 100644
--- a/sysdeps/unix/sysv/linux/pwrite64.c
+++ b/sysdeps/unix/sysv/linux/pwrite64.c
@@ -28,6 +28,7 @@  __libc_pwrite64 (int fd, const void *buf, size_t count, off64_t offset)
 {
   return SYSCALL_CANCEL (pwrite64, fd, buf, count, SYSCALL_LL64_PRW (offset));
 }
+
 weak_alias (__libc_pwrite64, __pwrite64)
 libc_hidden_weak (__pwrite64)
 weak_alias (__libc_pwrite64, pwrite64)
diff --git a/sysdeps/unix/sysv/linux/pwritev.c b/sysdeps/unix/sysv/linux/pwritev.c
index ce02996..7545cb3 100644
--- a/sysdeps/unix/sysv/linux/pwritev.c
+++ b/sysdeps/unix/sysv/linux/pwritev.c
@@ -50,4 +50,6 @@  pwritev (int fd, const struct iovec *vector, int count, off_t offset)
 #  define OFF_T off_t
 #  include <sysdeps/posix/pwritev_common.c>
 # endif /* __ASSUME_PREADV  */
+
+libc_hidden_def (pwritev)
 #endif
diff --git a/sysdeps/unix/sysv/linux/pwritev2.c b/sysdeps/unix/sysv/linux/pwritev2.c
new file mode 100644
index 0000000..72f0471
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/pwritev2.c
@@ -0,0 +1,51 @@ 
+/* Linux implementation of pwritev2.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <sys/uio.h>
+#include <sysdep-cancel.h>
+
+#ifndef __OFF_T_MATCHES_OFF64_T
+
+ssize_t
+pwritev2 (int fd, const struct iovec *vector, int count, off_t offset,
+	  int flags)
+{
+# ifdef __NR_pwritev2
+  ssize_t result = SYSCALL_CANCEL (pwritev2, fd, vector, count,
+				   LO_HI_LONG (offset), flags);
+  if (result >= 0 || errno != ENOSYS)
+    return result;
+# endif
+  /* Trying to emulate the pwritev2 syscall flags is troublesome:
+
+     * We can not temporary change the file state of the O_DSYNC and O_SYNC
+       flags to emulate RWF_{D}SYNC (attempts to change the state of using
+       fcntl are silently ignored).
+
+     * IOCB_HIPRI requires the file opened in O_DIRECT and uses an internal
+       semantic not provided by any other flag (O_NONBLOCK for instance).  */
+
+  if (flags != 0)
+    {
+      __set_errno (EOPNOTSUPP);
+      return -1;
+    }
+  return pwritev (fd, vector, count, offset);
+}
+
+#endif
diff --git a/sysdeps/unix/sysv/linux/pwritev64.c b/sysdeps/unix/sysv/linux/pwritev64.c
index 45fb90b..9dc4e55 100644
--- a/sysdeps/unix/sysv/linux/pwritev64.c
+++ b/sysdeps/unix/sysv/linux/pwritev64.c
@@ -48,7 +48,9 @@  pwritev64 (int fd, const struct iovec *vector, int count, off64_t offset)
 # define OFF_T off64_t
 # include <sysdeps/posix/pwritev_common.c>
 #endif
+libc_hidden_def (pwritev64)
 
 #ifdef __OFF_T_MATCHES_OFF64_T
 strong_alias (pwritev64, pwritev)
+libc_hidden_def (pwritev)
 #endif
diff --git a/sysdeps/unix/sysv/linux/pwritev64v2.c b/sysdeps/unix/sysv/linux/pwritev64v2.c
new file mode 100644
index 0000000..def9a0b
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/pwritev64v2.c
@@ -0,0 +1,55 @@ 
+/* Linux implementation of pwritev2 (LFS version).
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <sys/uio.h>
+#include <sysdep-cancel.h>
+
+#if !defined(__NR_pwritev64v2) && defined(__NR_pwritev2)
+# define __NR_pwritev64v2 __NR_pwritev2
+#endif
+
+ssize_t
+pwritev64v2 (int fd, const struct iovec *vector, int count, off64_t offset,
+	     int flags)
+{
+#ifdef __NR_pwritev64v2
+  ssize_t result = SYSCALL_CANCEL (pwritev64v2, fd, vector, count,
+				   LO_HI_LONG (offset), flags);
+  if (result >= 0 || errno != ENOSYS)
+    return result;
+#endif
+  /* Trying to emulate the pwritev2 syscall flags is troublesome:
+
+     * We can not temporary change the file state of the O_DSYNC and O_SYNC
+       flags to emulate RWF_{D}SYNC (attempts to change the state of using
+       fcntl are silently ignored).
+
+     * IOCB_HIPRI requires the file opened in O_DIRECT and uses an internal
+       semantic not provided by any other flag (O_NONBLOCK for instance).  */
+
+  if (flags != 0)
+    {
+      __set_errno (EOPNOTSUPP);
+      return -1;
+    }
+  return pwritev64 (fd, vector, count, offset);
+}
+
+#ifdef __OFF_T_MATCHES_OFF64_T
+strong_alias (pwritev64v2, pwritev2)
+#endif
diff --git a/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist b/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
index ed1b6bf..eb9e72f 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
@@ -1980,6 +1980,11 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist b/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
index 2e75d29..1402959 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
@@ -1881,6 +1881,11 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/sh/libc.abilist b/sysdeps/unix/sysv/linux/sh/libc.abilist
index bd74c0c..e9eefcb 100644
--- a/sysdeps/unix/sysv/linux/sh/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sh/libc.abilist
@@ -1866,6 +1866,11 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist b/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
index 5584838..967699e 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
@@ -1972,6 +1972,11 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist b/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
index efedbe2..9dd938a 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
@@ -1910,6 +1910,11 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist b/sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist
index ffd988a..68c9887 100644
--- a/sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist
@@ -2104,3 +2104,8 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
diff --git a/sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist b/sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist
index f0c13ce..97aa0f7 100644
--- a/sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist
@@ -2104,3 +2104,8 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
diff --git a/sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist b/sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist
index ffd988a..68c9887 100644
--- a/sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist
+++ b/sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist
@@ -2104,3 +2104,8 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
diff --git a/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist b/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
index f57004c..2032659 100644
--- a/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
@@ -1861,6 +1861,11 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist b/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
index 05629e1..11a278c 100644
--- a/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
@@ -2104,3 +2104,8 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F