mbox series

[v2,00/15] linux: Add new syscalls

Message ID 20220207174431.360355-1-adhemerval.zanella@linaro.org
Headers
Series linux: Add new syscalls |

Message

Adhemerval Zanella Netto Feb. 7, 2022, 5:44 p.m. UTC 
  This patchset adds two sets of Linux syscalls: the pidfd and the new
mount API.

The pidfd support was initially added with clone3 when used with
CLONE_PIDFD to return a file file descriptor referring to the child
process.  This set adds the missing pidfd_open (added on Linux 5.3),
pidfd_getfd (Linux 5.6), and pidfd_send_signal (Linux 5.1), along
with P_PIDFD flag use along waitid.  These newer syscalls allows
race free process signaling by avoiding the PID reuse.

Along with pidfd, two new syscalls are also added: process_madvise
and process_mrelease.  Both uses the pidfd to add a way to interact
with target memory, former acts as posix_madvise for target process
and later allows the caller to handle target memory cleanup at
process exit.

The second set is the new mount API added Linux 5.2, which adds
six syscalls: fsopen, fsmount, move_mount, fsconfig, fspick, and
open_tree.  It also adds mount_setattr which was added on Linux 5.12.
This is complete redesign of the mount API to allow more flexibility
with mount points, specially when used along namespaces.

Adhemerval Zanella (15):
  linux: Add pidfd_open
  linux: Add pidfd_getfd
  linux: Add pidfd_send_signal
  linux: Add P_PIDFD
  linux: Add tst-pidfd.c
  linux: Add process_madvise
  linux: Add process_mrelease
  linux: Add fsopen
  linux: Add fsmount
  linux: Add move_mount
  linux: Add fsconfig
  linux: Add fspick
  linux: Add open_tree
  linux: Add tst-mount to check for Linux new mount API
  linux: Add mount_setattr

 NEWS                                          |  14 +-
 bits/mman_ext.h                               |  21 +++
 misc/sys/mman.h                               |   3 +
 posix/Makefile                                |   2 +-
 posix/sys/wait.h                              |   7 +-
 sysdeps/generic/libc.abilist                  |   1 +
 sysdeps/mach/hurd/bits/types/idtype_t.h       |  12 ++
 sysdeps/unix/sysv/linux/Makefile              |  27 ++-
 sysdeps/unix/sysv/linux/Versions              |  14 ++
 sysdeps/unix/sysv/linux/aarch64/libc.abilist  |  12 ++
 sysdeps/unix/sysv/linux/alpha/libc.abilist    |  12 ++
 sysdeps/unix/sysv/linux/arc/libc.abilist      |  12 ++
 sysdeps/unix/sysv/linux/arm/be/libc.abilist   |  12 ++
 sysdeps/unix/sysv/linux/arm/le/libc.abilist   |  12 ++
 sysdeps/unix/sysv/linux/bits/mman_ext.h       |  35 ++++
 sysdeps/unix/sysv/linux/bits/types/idtype_t.h |  14 ++
 sysdeps/unix/sysv/linux/csky/libc.abilist     |  12 ++
 sysdeps/unix/sysv/linux/hppa/libc.abilist     |  12 ++
 sysdeps/unix/sysv/linux/i386/libc.abilist     |  12 ++
 sysdeps/unix/sysv/linux/ia64/libc.abilist     |  12 ++
 .../sysv/linux/m68k/coldfire/libc.abilist     |  12 ++
 .../unix/sysv/linux/m68k/m680x0/libc.abilist  |  12 ++
 .../sysv/linux/microblaze/be/libc.abilist     |  12 ++
 .../sysv/linux/microblaze/le/libc.abilist     |  12 ++
 .../sysv/linux/mips/mips32/fpu/libc.abilist   |  12 ++
 .../sysv/linux/mips/mips32/nofpu/libc.abilist |  12 ++
 .../sysv/linux/mips/mips64/n32/libc.abilist   |  12 ++
 .../sysv/linux/mips/mips64/n64/libc.abilist   |  12 ++
 sysdeps/unix/sysv/linux/nios2/libc.abilist    |  12 ++
 sysdeps/unix/sysv/linux/or1k/libc.abilist     |  12 ++
 .../linux/powerpc/powerpc32/fpu/libc.abilist  |  12 ++
 .../powerpc/powerpc32/nofpu/libc.abilist      |  12 ++
 .../linux/powerpc/powerpc64/be/libc.abilist   |  12 ++
 .../linux/powerpc/powerpc64/le/libc.abilist   |  12 ++
 .../unix/sysv/linux/riscv/rv32/libc.abilist   |  12 ++
 .../unix/sysv/linux/riscv/rv64/libc.abilist   |  12 ++
 .../unix/sysv/linux/s390/s390-32/libc.abilist |  12 ++
 .../unix/sysv/linux/s390/s390-64/libc.abilist |  12 ++
 sysdeps/unix/sysv/linux/sh/be/libc.abilist    |  12 ++
 sysdeps/unix/sysv/linux/sh/le/libc.abilist    |  12 ++
 .../sysv/linux/sparc/sparc32/libc.abilist     |  12 ++
 .../sysv/linux/sparc/sparc64/libc.abilist     |  12 ++
 sysdeps/unix/sysv/linux/sys/mount.h           | 115 ++++++++++++
 sysdeps/unix/sysv/linux/sys/pidfd.h           |  49 +++++
 sysdeps/unix/sysv/linux/syscalls.list         |  12 ++
 sysdeps/unix/sysv/linux/tst-mount-consts.py   |  61 +++++++
 sysdeps/unix/sysv/linux/tst-mount.c           | 119 ++++++++++++
 sysdeps/unix/sysv/linux/tst-pidfd-consts.py   |  49 +++++
 sysdeps/unix/sysv/linux/tst-pidfd.c           | 170 ++++++++++++++++++
 sysdeps/unix/sysv/linux/tst-process_madvise.c | 107 +++++++++++
 .../unix/sysv/linux/tst-process_mrelease.c    |  72 ++++++++
 .../unix/sysv/linux/x86_64/64/libc.abilist    |  12 ++
 .../unix/sysv/linux/x86_64/x32/libc.abilist   |  12 ++
 53 files changed, 1291 insertions(+), 9 deletions(-)
 create mode 100644 bits/mman_ext.h
 create mode 100644 sysdeps/mach/hurd/bits/types/idtype_t.h
 create mode 100644 sysdeps/unix/sysv/linux/bits/mman_ext.h
 create mode 100644 sysdeps/unix/sysv/linux/bits/types/idtype_t.h
 create mode 100644 sysdeps/unix/sysv/linux/sys/pidfd.h
 create mode 100755 sysdeps/unix/sysv/linux/tst-mount-consts.py
 create mode 100644 sysdeps/unix/sysv/linux/tst-mount.c
 create mode 100644 sysdeps/unix/sysv/linux/tst-pidfd-consts.py
 create mode 100644 sysdeps/unix/sysv/linux/tst-pidfd.c
 create mode 100644 sysdeps/unix/sysv/linux/tst-process_madvise.c
 create mode 100644 sysdeps/unix/sysv/linux/tst-process_mrelease.c

Comments

Carlos O'Donell May 16, 2022, 9:12 p.m. UTC | #1 
On 2/7/22 12:44, Adhemerval Zanella via Libc-alpha wrote:
> This patchset adds two sets of Linux syscalls: the pidfd and the new
> mount API.
> 
> The pidfd support was initially added with clone3 when used with
> CLONE_PIDFD to return a file file descriptor referring to the child
> process.  This set adds the missing pidfd_open (added on Linux 5.3),
> pidfd_getfd (Linux 5.6), and pidfd_send_signal (Linux 5.1), along
> with P_PIDFD flag use along waitid.  These newer syscalls allows
> race free process signaling by avoiding the PID reuse.
> 
> Along with pidfd, two new syscalls are also added: process_madvise
> and process_mrelease.  Both uses the pidfd to add a way to interact
> with target memory, former acts as posix_madvise for target process
> and later allows the caller to handle target memory cleanup at
> process exit.
> 
> The second set is the new mount API added Linux 5.2, which adds
> six syscalls: fsopen, fsmount, move_mount, fsconfig, fspick, and
> open_tree.  It also adds mount_setattr which was added on Linux 5.12.
> This is complete redesign of the mount API to allow more flexibility
> with mount points, specially when used along namespaces.

Thanks for working on this. These syscalls are generally usable by userspace and
fs tooling. We should expose them as syscalls so tooling can just call the wrappers.


> Adhemerval Zanella (15):


>   linux: Add pidfd_open
>   linux: Add pidfd_getfd
>   linux: Add pidfd_send_signal
>   linux: Add P_PIDFD
>   linux: Add tst-pidfd.c

These 5 are ready and given my review I think we can commit them.

>   linux: Add process_madvise
>   linux: Add process_mrelease
>   linux: Add fsopen
>   linux: Add fsmount
>   linux: Add move_mount
>   linux: Add fsconfig
>   linux: Add fspick
>   linux: Add open_tree
>   linux: Add tst-mount to check for Linux new mount API
>   linux: Add mount_setattr

I went through 5.18.0-rc7 to confirm coverage and review the syscalls.

Some arches have their own syscall.tbl tables, so I looked those over
to ensure they were updated.

I found no architectures with missing syscalls.

- arm (aarch64)
	pidfd_open [present]
	pidfd_getfd [present]
	pidfd_send_signal [present]
	process_madvise [present]
	process_mrelease [present]
	fsopen [present]
	fsmount [present]
	move_mount [present]
	fsconfig [present]
	fspick [present]
	open_tree [present]
	mount_setattr [present]

- alpha
	pidfd_open [present]
	pidfd_getfd [present]
	pidfd_send_signal [present]
	process_madvise [present]
	process_mrelease [present]
	fsopen [present]
	fsmount [present]
	move_mount [present]
	fsconfig [present]
	fspick [present]
	open_tree [present]
	mount_setattr [present]

- arc
	- UAPI generic port. Nothing to review.

- csky
	- UAPI generic port. Nothing to review.

- hppa
	pidfd_open [present]
	pidfd_getfd [present]
	pidfd_send_signal [present]
	process_madvise [present]
	process_mrelease [present]
	fsopen [present]
	fsmount [present]
	move_mount [present]
	fsconfig [present]
	fspick [present]
	open_tree [present]
	mount_setattr [present]

- i686
	pidfd_open [present]
	pidfd_getfd [present]
	pidfd_send_signal [present]
	process_madvise [present]
	process_mrelease [present]
	fsopen [present]
	fsmount [present]
	move_mount [present]
	fsconfig [present]
	fspick [present]
	open_tree [present]
	mount_setattr [present]

- x86_64
	pidfd_open [present]
	pidfd_getfd [present]
	pidfd_send_signal [present]
	process_madvise [present]
	process_mrelease [present]
	fsopen [present]
	fsmount [present]
	move_mount [present]
	fsconfig [present]
	fspick [present]
	open_tree [present]
	mount_setattr [present]

- ia64
	pidfd_open [present]
	pidfd_getfd [present]
	pidfd_send_signal [present]
	process_madvise [present]
	process_mrelease [present]
	fsopen [present]
	fsmount [present]
	move_mount [present]
	fsconfig [present]
	fspick [present]
	open_tree [present]
	mount_setattr [present]

- m68k
	pidfd_open [present]
	pidfd_getfd [present]
	pidfd_send_signal [present]
	process_madvise [present]
	process_mrelease [present]
	fsopen [present]
	fsmount [present]
	move_mount [present]
	fsconfig [present]
	fspick [present]
	open_tree [present]
	mount_setattr [present]

- microblaze
	pidfd_open [present]
	pidfd_getfd [present]
	pidfd_send_signal [present]
	process_madvise [present]
	process_mrelease [present]
	fsopen [present]
	fsmount [present]
	move_mount [present]
	fsconfig [present]
	fspick [present]
	open_tree [present]
	mount_setattr [present]

- mips
- mips64
[Verify n64, n32, o32]
	pidfd_open [present]
	pidfd_getfd [present]
	pidfd_send_signal [present]
	process_madvise [present]
	process_mrelease [present]
	fsopen [present]
	fsmount [present]
	move_mount [present]
	fsconfig [present]
	fspick [present]
	open_tree [present]
	mount_setattr [present]

- or1k
	- UAPI generic port. Nothing to review.

- powerpc
- powerpc64
	pidfd_open [present]
	pidfd_getfd [present]
	pidfd_send_signal [present]
	process_madvise [present]
	process_mrelease [present]
	fsopen [present]
	fsmount [present]
	move_mount [present]
	fsconfig [present]
	fspick [present]
	open_tree [present]
	mount_setattr [present]

- s390
- s390x
	pidfd_open [present]
	pidfd_getfd [present]
	pidfd_send_signal [present]
	process_madvise [present]
	process_mrelease [present]
	fsopen [present]
	fsmount [present]
	move_mount [present]
	fsconfig [present]
	fspick [present]
	open_tree [present]
	mount_setattr [present]

- riscv32
- riscv64
	- UAPI generic port. Nothing to review.

- sh[34]
	pidfd_open [present]
	pidfd_getfd [present]
	pidfd_send_signal [present]
	process_madvise [present]
	process_mrelease [present]
	fsopen [present]
	fsmount [present]
	move_mount [present]
	fsconfig [present]
	fspick [present]
	open_tree [present]
	mount_setattr [present]

- sparc
- sparc64
	pidfd_open [present]
	pidfd_getfd [present]
	pidfd_send_signal [present]
	process_madvise [present]
	process_mrelease [present]
	fsopen [present]
	fsmount [present]
	move_mount [present]
	fsconfig [present]
	fspick [present]
	open_tree [present]
	mount_setattr [present]
 
>  NEWS                                          |  14 +-
>  bits/mman_ext.h                               |  21 +++
>  misc/sys/mman.h                               |   3 +
>  posix/Makefile                                |   2 +-
>  posix/sys/wait.h                              |   7 +-
>  sysdeps/generic/libc.abilist                  |   1 +
>  sysdeps/mach/hurd/bits/types/idtype_t.h       |  12 ++
>  sysdeps/unix/sysv/linux/Makefile              |  27 ++-
>  sysdeps/unix/sysv/linux/Versions              |  14 ++
>  sysdeps/unix/sysv/linux/aarch64/libc.abilist  |  12 ++
>  sysdeps/unix/sysv/linux/alpha/libc.abilist    |  12 ++
>  sysdeps/unix/sysv/linux/arc/libc.abilist      |  12 ++
>  sysdeps/unix/sysv/linux/arm/be/libc.abilist   |  12 ++
>  sysdeps/unix/sysv/linux/arm/le/libc.abilist   |  12 ++
>  sysdeps/unix/sysv/linux/bits/mman_ext.h       |  35 ++++
>  sysdeps/unix/sysv/linux/bits/types/idtype_t.h |  14 ++
>  sysdeps/unix/sysv/linux/csky/libc.abilist     |  12 ++
>  sysdeps/unix/sysv/linux/hppa/libc.abilist     |  12 ++
>  sysdeps/unix/sysv/linux/i386/libc.abilist     |  12 ++
>  sysdeps/unix/sysv/linux/ia64/libc.abilist     |  12 ++
>  .../sysv/linux/m68k/coldfire/libc.abilist     |  12 ++
>  .../unix/sysv/linux/m68k/m680x0/libc.abilist  |  12 ++
>  .../sysv/linux/microblaze/be/libc.abilist     |  12 ++
>  .../sysv/linux/microblaze/le/libc.abilist     |  12 ++
>  .../sysv/linux/mips/mips32/fpu/libc.abilist   |  12 ++
>  .../sysv/linux/mips/mips32/nofpu/libc.abilist |  12 ++
>  .../sysv/linux/mips/mips64/n32/libc.abilist   |  12 ++
>  .../sysv/linux/mips/mips64/n64/libc.abilist   |  12 ++
>  sysdeps/unix/sysv/linux/nios2/libc.abilist    |  12 ++
>  sysdeps/unix/sysv/linux/or1k/libc.abilist     |  12 ++
>  .../linux/powerpc/powerpc32/fpu/libc.abilist  |  12 ++
>  .../powerpc/powerpc32/nofpu/libc.abilist      |  12 ++
>  .../linux/powerpc/powerpc64/be/libc.abilist   |  12 ++
>  .../linux/powerpc/powerpc64/le/libc.abilist   |  12 ++
>  .../unix/sysv/linux/riscv/rv32/libc.abilist   |  12 ++
>  .../unix/sysv/linux/riscv/rv64/libc.abilist   |  12 ++
>  .../unix/sysv/linux/s390/s390-32/libc.abilist |  12 ++
>  .../unix/sysv/linux/s390/s390-64/libc.abilist |  12 ++
>  sysdeps/unix/sysv/linux/sh/be/libc.abilist    |  12 ++
>  sysdeps/unix/sysv/linux/sh/le/libc.abilist    |  12 ++
>  .../sysv/linux/sparc/sparc32/libc.abilist     |  12 ++
>  .../sysv/linux/sparc/sparc64/libc.abilist     |  12 ++
>  sysdeps/unix/sysv/linux/sys/mount.h           | 115 ++++++++++++
>  sysdeps/unix/sysv/linux/sys/pidfd.h           |  49 +++++
>  sysdeps/unix/sysv/linux/syscalls.list         |  12 ++
>  sysdeps/unix/sysv/linux/tst-mount-consts.py   |  61 +++++++
>  sysdeps/unix/sysv/linux/tst-mount.c           | 119 ++++++++++++
>  sysdeps/unix/sysv/linux/tst-pidfd-consts.py   |  49 +++++
>  sysdeps/unix/sysv/linux/tst-pidfd.c           | 170 ++++++++++++++++++
>  sysdeps/unix/sysv/linux/tst-process_madvise.c | 107 +++++++++++
>  .../unix/sysv/linux/tst-process_mrelease.c    |  72 ++++++++
>  .../unix/sysv/linux/x86_64/64/libc.abilist    |  12 ++
>  .../unix/sysv/linux/x86_64/x32/libc.abilist   |  12 ++
>  53 files changed, 1291 insertions(+), 9 deletions(-)
>  create mode 100644 bits/mman_ext.h
>  create mode 100644 sysdeps/mach/hurd/bits/types/idtype_t.h
>  create mode 100644 sysdeps/unix/sysv/linux/bits/mman_ext.h
>  create mode 100644 sysdeps/unix/sysv/linux/bits/types/idtype_t.h
>  create mode 100644 sysdeps/unix/sysv/linux/sys/pidfd.h
>  create mode 100755 sysdeps/unix/sysv/linux/tst-mount-consts.py
>  create mode 100644 sysdeps/unix/sysv/linux/tst-mount.c
>  create mode 100644 sysdeps/unix/sysv/linux/tst-pidfd-consts.py
>  create mode 100644 sysdeps/unix/sysv/linux/tst-pidfd.c
>  create mode 100644 sysdeps/unix/sysv/linux/tst-process_madvise.c
>  create mode 100644 sysdeps/unix/sysv/linux/tst-process_mrelease.c
>