Patchwork [v3] Fix Linux fcntl OFD locks for non-LFS architectures (BZ#20251)

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Submitter Adhemerval Zanella Netto
Date June 13, 2018, 6:50 p.m.
Message ID <1528915841-10611-1-git-send-email-adhemerval.zanella@linaro.org>
Download mbox | patch
Permalink /patch/27808/
State New
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Comments

Adhemerval Zanella Netto - June 13, 2018, 6:50 p.m.
Changes from previous version:

  - Rebase against 329ea513b4 (Avoid cancellable I/O primitives in ld.so.).
    The main change is to rename __fcntl_nocancel to __fcntl64_nocancel
    now that fcntl follows the usual LFS naming scheme.

---

This patch fixes the OFD ("file private") locks for architectures that
support non-LFS flock definition (__USE_FILE_OFFSET64 not defined). The
issue in this case is both F_OFD_{GETLK,SETLK,SETLKW} and
F_{SET,GET}L{W}K64 expects a flock64 argument and when using old F_OFD_*
flags with a non LFS flock argument the kernel might interpret the underlying
data wrongly.  Kernel idea originally was to avoid using such flags in
non-LFS syscall, but since GLIBC uses fcntl with LFS semantic as default
it is possible to provide the functionality and avoid the bogus struct kernel
passing by adjusting the struct manually for the required flags.

The idea follows other LFS interfaces that provide two symbols:

  1. A new LFS fcntl64 is added on default ABI with the usual macros to select
     it for FILE_OFFSET_BITS=64.

  2. The Linux non-LFS fcntl use a stack allocated struct flock64 for
     F_OFD_{GETLK,SETLK,SETLKW} copy the results on the user provided struct.

  3. Keep a compat symbol with old broken semantic for architectures that do
     not define __OFF_T_MATCHES_OFF64_T.

So for architectures which defines __USE_FILE_OFFSET64, fcntl64 will aliased
to fcntl and no adjustment would be required.

Also F_OFD_SETLKW command is handled a cancellation point, as for L_SETLKW{64}.

Checked on x86_64-linux-gnu and i686-linux-gnu.

	[BZ #20251]
	* NEWS: Mention fcntl64 addition.
	* csu/check_fds.c: Replace __fcntl_nocancel by __fcntl64_nocancel.
	* login/utmp_file.c: Likewise.
	* sysdeps/posix/fdopendir.c: Likewise.
	* sysdeps/posix/opendir.c: Likewise.
	* sysdeps/unix/pt-fcntl.c: Likewise.
	* include/fcntl.h (__libc_fcntl64, __fcntl64,
	__fcntl64_nocancel_adjusted): New prototype.
	(__fcntl_nocancel_adjusted): Remove prototype.
	* io/Makefile (routines): Add fcntl64.
	(CFLAGS-fcntl64.c): New rule.
	* io/Versions [GLIBC_2.28] (fcntl64): New symbol.
	[GLIBC_PRIVATE] (__libc_fcntl): Rename to __libc_fcntl64.
	* io/fcntl.h (fcntl64): Add prototype and redirect if
	__USE_FILE_OFFSET64 is defined.
	* io/fcntl64.c: New file.
	* manual/llio.text: Add a note for which commands fcntl acts a
	cancellation point.
	* nptl/Makefile (CFLAGS-fcntl64.c): New rule.
	* sysdeps/mach/hurd/fcntl.c: Alias fcntl to fcntl64 symbols.
	* sysdeps/mach/hurd/i386/libc.abilist [GLIBC_2.28] (fcntl, fcntl64):
	New symbols.
	* sysdeps/unix/sysv/linux/fcntl.c (__libc_fcntl): Fix F_GETLK64,
	F_OFD_GETLK, F_SETLK64, F_SETLKW64, F_OFD_SETLK, and F_OFD_SETLKW for
	non-LFS case.
	* sysdeps/unix/sysv/linux/fcntl64.c: New file.
	* sysdeps/unix/sysv/linux/fcntl_nocancel.c (__fcntl_nocancel): Rename
	to __fcntl64_nocancel.
	(__fcntl_nocancel_adjusted): Rename to __fcntl64_nocancel_adjusted.
	* sysdeps/unix/sysv/linux/not-cancel.h (__fcntl_nocancel): Rename
	to __fcntl64_nocancel.
	* sysdeps/unix/sysv/linux/tst-ofdlocks.c: New file.
	* sysdeps/unix/sysv/linux/Makefile (tests): Add tst-ofdlocks.
	* sysdeps/unix/sysv/linux/aarch64/libc.abilist [GLIBC_2.28]
	(fcntl64): New symbol.
	* sysdeps/unix/sysv/linux/alpha/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/ia64/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist: Likewise.
	* sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/64/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/arm/libc.abilist [GLIBC_2.28] (fcntl,
	fcntl64): Likewise.
	* sysdeps/unix/sysv/linux/hppa/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/i386/libc.abilis: Likewise.
	* sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/microblaze/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/nios2/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist:
	Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist:
	Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/sh/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist: Likewise.
---
 ChangeLog                                          | 67 ++++++++++++++++
 NEWS                                               |  6 ++
 csu/check_fds.c                                    |  2 +-
 include/fcntl.h                                    |  7 +-
 io/Makefile                                        |  3 +-
 io/Versions                                        |  5 +-
 io/fcntl.h                                         | 11 +++
 io/fcntl64.c                                       | 38 +++++++++
 login/utmp_file.c                                  |  4 +-
 manual/llio.texi                                   | 13 ++--
 nptl/Makefile                                      |  1 +
 sysdeps/mach/hurd/fcntl.c                          |  5 ++
 sysdeps/mach/hurd/i386/libc.abilist                |  2 +
 sysdeps/posix/fdopendir.c                          |  2 +-
 sysdeps/posix/opendir.c                            |  2 +-
 sysdeps/unix/pt-fcntl.c                            |  2 +-
 sysdeps/unix/sysv/linux/Makefile                   |  2 +-
 sysdeps/unix/sysv/linux/aarch64/libc.abilist       |  1 +
 sysdeps/unix/sysv/linux/alpha/libc.abilist         |  1 +
 sysdeps/unix/sysv/linux/arm/libc.abilist           |  2 +
 sysdeps/unix/sysv/linux/fcntl.c                    | 89 +++++++++++++++++++---
 sysdeps/unix/sysv/linux/fcntl64.c                  | 63 +++++++++++++++
 sysdeps/unix/sysv/linux/fcntl_nocancel.c           |  8 +-
 sysdeps/unix/sysv/linux/hppa/libc.abilist          |  2 +
 sysdeps/unix/sysv/linux/i386/libc.abilist          |  2 +
 sysdeps/unix/sysv/linux/ia64/libc.abilist          |  1 +
 sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist |  2 +
 sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist   |  2 +
 sysdeps/unix/sysv/linux/microblaze/libc.abilist    |  2 +
 .../unix/sysv/linux/mips/mips32/fpu/libc.abilist   |  2 +
 .../unix/sysv/linux/mips/mips32/nofpu/libc.abilist |  2 +
 .../unix/sysv/linux/mips/mips64/n32/libc.abilist   |  2 +
 .../unix/sysv/linux/mips/mips64/n64/libc.abilist   |  1 +
 sysdeps/unix/sysv/linux/nios2/libc.abilist         |  2 +
 sysdeps/unix/sysv/linux/not-cancel.h               |  4 +-
 .../sysv/linux/powerpc/powerpc32/fpu/libc.abilist  |  2 +
 .../linux/powerpc/powerpc32/nofpu/libc.abilist     |  2 +
 .../sysv/linux/powerpc/powerpc64/libc-le.abilist   |  1 +
 .../unix/sysv/linux/powerpc/powerpc64/libc.abilist |  1 +
 sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist    |  1 +
 sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist  |  2 +
 sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist  |  1 +
 sysdeps/unix/sysv/linux/sh/libc.abilist            |  2 +
 sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist |  2 +
 sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist |  1 +
 sysdeps/unix/sysv/linux/tst-ofdlocks.c             | 76 ++++++++++++++++++
 sysdeps/unix/sysv/linux/x86_64/64/libc.abilist     |  1 +
 sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist    |  1 +
 48 files changed, 420 insertions(+), 33 deletions(-)
 create mode 100644 io/fcntl64.c
 create mode 100644 sysdeps/unix/sysv/linux/fcntl64.c
 create mode 100644 sysdeps/unix/sysv/linux/tst-ofdlocks.c

Patch

diff --git a/NEWS b/NEWS
index d51fa09..5996e53 100644
--- a/NEWS
+++ b/NEWS
@@ -110,6 +110,12 @@  Deprecated and removed features, and other changes affecting compatibility:
   restriction (rejecting '_' in host names, among other things) has been
   removed, for increased compatibility with non-IDN name resolution.
 
+* The fcntl function now have a Long File Support variant named fcntl64.  It
+  is added to fix some Linux Open File Description (OFD) locks usage on non
+  LFS mode.  As for others *64 functions, fcntl64 semantics are analogous with
+  fcntl and LFS support is handled transparently.  Also for Linux, the OFD
+  locks act as a cancellation entrypoint.
+
 Changes to build and runtime requirements:
 
   [Add changes to build and runtime requirements here]
diff --git a/csu/check_fds.c b/csu/check_fds.c
index 605ee4f..ad1763b 100644
--- a/csu/check_fds.c
+++ b/csu/check_fds.c
@@ -39,7 +39,7 @@ 
 static void
 check_one_fd (int fd, int mode)
 {
-  if (__builtin_expect (__fcntl_nocancel (fd, F_GETFD), 0) == -1
+  if (__builtin_expect (__fcntl64_nocancel (fd, F_GETFD), 0) == -1
       && errno == EBADF)
     {
       const char *name;
diff --git a/include/fcntl.h b/include/fcntl.h
index 966f797..be43504 100644
--- a/include/fcntl.h
+++ b/include/fcntl.h
@@ -10,11 +10,16 @@  extern int __libc_open (const char *file, int oflag, ...);
 libc_hidden_proto (__libc_open)
 extern int __libc_fcntl (int fd, int cmd, ...);
 libc_hidden_proto (__libc_fcntl)
-extern int __fcntl_nocancel_adjusted (int fd, int cmd, void *arg) attribute_hidden;
+extern int __fcntl64_nocancel_adjusted (int fd, int cmd, void *arg)
+   attribute_hidden;
+extern int __libc_fcntl64 (int fd, int cmd, ...);
+libc_hidden_proto (__libc_fcntl64)
 extern int __open (const char *__file, int __oflag, ...);
 libc_hidden_proto (__open)
 extern int __fcntl (int __fd, int __cmd, ...);
 libc_hidden_proto (__fcntl)
+extern int __fcntl64 (int __fd, int __cmd, ...) attribute_hidden;
+libc_hidden_proto (__fcntl64)
 extern int __openat (int __fd, const char *__file, int __oflag, ...)
   __nonnull ((2));
 libc_hidden_proto (__openat)
diff --git a/io/Makefile b/io/Makefile
index 2117cb6..4a0d8fe 100644
--- a/io/Makefile
+++ b/io/Makefile
@@ -40,7 +40,7 @@  routines :=								\
 	mkdir mkdirat							\
 	open open_2 open64 open64_2 openat openat_2 openat64 openat64_2	\
 	read write lseek lseek64 access euidaccess faccessat		\
-	fcntl flock lockf lockf64					\
+	fcntl fcntl64 flock lockf lockf64				\
 	close dup dup2 dup3 pipe pipe2					\
 	creat creat64							\
 	chdir fchdir							\
@@ -89,6 +89,7 @@  CFLAGS-open64.c += -fexceptions -fasynchronous-unwind-tables
 CFLAGS-creat.c += -fexceptions -fasynchronous-unwind-tables
 CFLAGS-creat64.c += -fexceptions -fasynchronous-unwind-tables
 CFLAGS-fcntl.c += -fexceptions -fasynchronous-unwind-tables
+CFLAGS-fcntl64.c += -fexceptions -fasynchronous-unwind-tables
 CFLAGS-poll.c += -fexceptions -fasynchronous-unwind-tables
 CFLAGS-ppoll.c += -fexceptions -fasynchronous-unwind-tables
 CFLAGS-lockf.c += -fexceptions
diff --git a/io/Versions b/io/Versions
index 4448b71..98037fb 100644
--- a/io/Versions
+++ b/io/Versions
@@ -128,8 +128,11 @@  libc {
   GLIBC_2.27 {
     copy_file_range;
   }
+  GLIBC_2.28 {
+    fcntl64;
+  }
   GLIBC_PRIVATE {
-    __libc_fcntl;
+    __libc_fcntl64;
     __fcntl_nocancel;
     __open64_nocancel;
     __write_nocancel;
diff --git a/io/fcntl.h b/io/fcntl.h
index 69a4394..3afc620 100644
--- a/io/fcntl.h
+++ b/io/fcntl.h
@@ -167,7 +167,18 @@  typedef __pid_t pid_t;
 
    This function is a cancellation point and therefore not marked with
    __THROW.  */
+#ifndef __USE_FILE_OFFSET64
 extern int fcntl (int __fd, int __cmd, ...);
+#else
+# ifdef __REDIRECT
+extern int __REDIRECT (fcntl, (int __fd, int __cmd, ...), fcntl64);
+# else
+#  define fcntl fcntl64
+# endif
+#endif
+#ifdef __USE_LARGEFILE64
+extern int fcntl64 (int __fd, int __cmd, ...);
+#endif
 
 /* Open FILE and return a new file descriptor for it, or -1 on error.
    OFLAG determines the type of access used.  If O_CREAT or O_TMPFILE is set
diff --git a/io/fcntl64.c b/io/fcntl64.c
new file mode 100644
index 0000000..f4e6809
--- /dev/null
+++ b/io/fcntl64.c
@@ -0,0 +1,38 @@ 
+/* Manipulate file descriptor.  Stub LFS version.
+   Copyright (C) 2018 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 <errno.h>
+#include <fcntl.h>
+
+/* Perform file control operations on FD.  */
+int
+__fcntl64 (int fd, int cmd, ...)
+{
+  if (fd < 0)
+    {
+      __set_errno (EBADF);
+      return -1;
+    }
+
+  __set_errno (ENOSYS);
+  return -1;
+}
+libc_hidden_def (__fcntl64)
+stub_warning (fcntl64)
+
+weak_alias (__fcntl64, fcntl64)
diff --git a/login/utmp_file.c b/login/utmp_file.c
index 72dd213..040a505 100644
--- a/login/utmp_file.c
+++ b/login/utmp_file.c
@@ -82,7 +82,7 @@  static void timeout_handler (int signum) {};
   memset (&fl, '\0', sizeof (struct flock));				      \
   fl.l_type = (type);							      \
   fl.l_whence = SEEK_SET;						      \
-  if (__fcntl_nocancel ((fd), F_SETLKW, &fl) < 0)
+  if (__fcntl64_nocancel ((fd), F_SETLKW, &fl) < 0)
 
 #define LOCKING_FAILED() \
   goto unalarm_return
@@ -90,7 +90,7 @@  static void timeout_handler (int signum) {};
 #define UNLOCK_FILE(fd) \
   /* Unlock the file.  */						      \
   fl.l_type = F_UNLCK;							      \
-  __fcntl_nocancel ((fd), F_SETLKW, &fl);				      \
+  __fcntl64_nocancel ((fd), F_SETLKW, &fl);				      \
 									      \
  unalarm_return:							      \
   /* Reset the signal handler and alarm.  We must reset the alarm	      \
diff --git a/manual/llio.texi b/manual/llio.texi
index 82f03be..e840c55 100644
--- a/manual/llio.texi
+++ b/manual/llio.texi
@@ -3281,12 +3281,13 @@  Set process or process group ID to receive @code{SIGIO} signals.
 @xref{Interrupt Input}.
 @end vtable
 
-This function is a cancellation point in multi-threaded programs.  This
-is a problem if the thread allocates some resources (like memory, file
-descriptors, semaphores or whatever) at the time @code{fcntl} is
-called.  If the thread gets canceled these resources stay allocated
-until the program ends.  To avoid this calls to @code{fcntl} should be
-protected using cancellation handlers.
+This function is a cancellation point in multi-threaded programs for the
+commands @code{F_SETLKW} (and the LFS analogous @code{F_SETLKW64}) and
+@code {F_OFD_SETLKW}.  This is a problem if the thread allocates some
+resources (like memory, file descriptors, semaphores or whatever) at the time
+@code{fcntl} is called.  If the thread gets canceled these resources stay
+allocated until the program ends.  To avoid this calls to @code{fcntl} should
+be protected using cancellation handlers.
 @c ref pthread_cleanup_push / pthread_cleanup_pop
 @end deftypefun
 
diff --git a/nptl/Makefile b/nptl/Makefile
index 6cfc8c6..0f9c44a 100644
--- a/nptl/Makefile
+++ b/nptl/Makefile
@@ -191,6 +191,7 @@  CFLAGS-sem_timedwait.c += -fexceptions -fasynchronous-unwind-tables
 
 # These are the function wrappers we have to duplicate here.
 CFLAGS-fcntl.c += -fexceptions -fasynchronous-unwind-tables
+CFLAGS-fcntl64.c += -fexceptions -fasynchronous-unwind-tables
 CFLAGS-lockf.c += -fexceptions
 CFLAGS-pread.c += -fexceptions -fasynchronous-unwind-tables
 CFLAGS-pread64.c += -fexceptions -fasynchronous-unwind-tables
diff --git a/sysdeps/mach/hurd/fcntl.c b/sysdeps/mach/hurd/fcntl.c
index 0b23164..598317d 100644
--- a/sysdeps/mach/hurd/fcntl.c
+++ b/sysdeps/mach/hurd/fcntl.c
@@ -210,3 +210,8 @@  libc_hidden_def (__libc_fcntl)
 weak_alias (__libc_fcntl, __fcntl)
 libc_hidden_weak (__fcntl)
 weak_alias (__libc_fcntl, fcntl)
+
+strong_alias (__libc_fcntl, __libc_fcntl64)
+libc_hidden_def (__libc_fcntl64)
+weak_alias (__libc_fcntl64, __fcntl64)
+libc_hidden_weak (__fcntl64)
diff --git a/sysdeps/mach/hurd/i386/libc.abilist b/sysdeps/mach/hurd/i386/libc.abilist
index 2cb5070..3d46de7 100644
--- a/sysdeps/mach/hurd/i386/libc.abilist
+++ b/sysdeps/mach/hurd/i386/libc.abilist
@@ -2033,6 +2033,8 @@  GLIBC_2.27 wcstof64 F
 GLIBC_2.27 wcstof64_l F
 GLIBC_2.27 wcstof64x F
 GLIBC_2.27 wcstof64x_l F
+GLIBC_2.28 fcntl F
+GLIBC_2.28 fcntl64 F
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
 GLIBC_2.3 __ctype_toupper_loc F
diff --git a/sysdeps/posix/fdopendir.c b/sysdeps/posix/fdopendir.c
index dafb5d2..b72eecc 100644
--- a/sysdeps/posix/fdopendir.c
+++ b/sysdeps/posix/fdopendir.c
@@ -38,7 +38,7 @@  __fdopendir (int fd)
     }
 
   /* Make sure the descriptor allows for reading.  */
-  int flags = __fcntl_nocancel (fd, F_GETFL);
+  int flags = __fcntl64_nocancel (fd, F_GETFL);
   if (__glibc_unlikely (flags == -1))
     return NULL;
   if (__glibc_unlikely ((flags & O_ACCMODE) == O_WRONLY))
diff --git a/sysdeps/posix/opendir.c b/sysdeps/posix/opendir.c
index 0875385..bb6bd7c 100644
--- a/sysdeps/posix/opendir.c
+++ b/sysdeps/posix/opendir.c
@@ -99,7 +99,7 @@  __alloc_dir (int fd, bool close_fd, int flags, const struct stat64 *statp)
   /* We have to set the close-on-exit flag if the user provided the
      file descriptor.  */
   if (!close_fd
-      && __glibc_unlikely (__fcntl_nocancel (fd, F_SETFD, FD_CLOEXEC) < 0))
+      && __glibc_unlikely (__fcntl64_nocancel (fd, F_SETFD, FD_CLOEXEC) < 0))
 	goto lose;
 
   const size_t default_allocation = (4 * BUFSIZ < sizeof (struct dirent64)
diff --git a/sysdeps/unix/pt-fcntl.c b/sysdeps/unix/pt-fcntl.c
index 8113d52..3d64054 100644
--- a/sysdeps/unix/pt-fcntl.c
+++ b/sysdeps/unix/pt-fcntl.c
@@ -37,7 +37,7 @@  fcntl_compat (int fd, int cmd, ...)
   va_start (ap, cmd);
   arg = va_arg (ap, void *);
   va_end (ap);
-  return __libc_fcntl (fd, cmd, arg);
+  return __libc_fcntl64 (fd, cmd, arg);
 }
 
 weak_alias (fcntl_compat, fcntl_alias)
diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile
index 215fd5d..f0c9e6f 100644
--- a/sysdeps/unix/sysv/linux/Makefile
+++ b/sysdeps/unix/sysv/linux/Makefile
@@ -45,7 +45,7 @@  sysdep_headers += sys/mount.h sys/acct.h sys/sysctl.h \
 tests += tst-clone tst-clone2 tst-clone3 tst-fanotify tst-personality \
 	 tst-quota tst-sync_file_range tst-sysconf-iov_max tst-ttyname \
 	 test-errno-linux tst-memfd_create tst-mlock2 tst-pkey \
-	 tst-rlimit-infinity
+	 tst-rlimit-infinity tst-ofdlocks
 
 # Generate the list of SYS_* macros for the system calls (__NR_*
 # macros).  The file syscall-names.list contains all possible system
diff --git a/sysdeps/unix/sysv/linux/aarch64/libc.abilist b/sysdeps/unix/sysv/linux/aarch64/libc.abilist
index 80cdb98..884d0df 100644
--- a/sysdeps/unix/sysv/linux/aarch64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/aarch64/libc.abilist
@@ -2131,3 +2131,4 @@  GLIBC_2.27 wcstof64 F
 GLIBC_2.27 wcstof64_l F
 GLIBC_2.27 wcstof64x F
 GLIBC_2.27 wcstof64x_l F
+GLIBC_2.28 fcntl64 F
diff --git a/sysdeps/unix/sysv/linux/alpha/libc.abilist b/sysdeps/unix/sysv/linux/alpha/libc.abilist
index c761f61..28d54b9 100644
--- a/sysdeps/unix/sysv/linux/alpha/libc.abilist
+++ b/sysdeps/unix/sysv/linux/alpha/libc.abilist
@@ -2026,6 +2026,7 @@  GLIBC_2.27 wcstof64 F
 GLIBC_2.27 wcstof64_l F
 GLIBC_2.27 wcstof64x F
 GLIBC_2.27 wcstof64x_l F
+GLIBC_2.28 fcntl64 F
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
 GLIBC_2.3 __ctype_toupper_loc F
diff --git a/sysdeps/unix/sysv/linux/arm/libc.abilist b/sysdeps/unix/sysv/linux/arm/libc.abilist
index 6aa58c3..dfde3bd 100644
--- a/sysdeps/unix/sysv/linux/arm/libc.abilist
+++ b/sysdeps/unix/sysv/linux/arm/libc.abilist
@@ -115,6 +115,8 @@  GLIBC_2.27 wcstof32x F
 GLIBC_2.27 wcstof32x_l F
 GLIBC_2.27 wcstof64 F
 GLIBC_2.27 wcstof64_l F
+GLIBC_2.28 fcntl F
+GLIBC_2.28 fcntl64 F
 GLIBC_2.4 _Exit F
 GLIBC_2.4 _IO_2_1_stderr_ D 0xa0
 GLIBC_2.4 _IO_2_1_stdin_ D 0xa0
diff --git a/sysdeps/unix/sysv/linux/fcntl.c b/sysdeps/unix/sysv/linux/fcntl.c
index e3992dc..0e37ed0 100644
--- a/sysdeps/unix/sysv/linux/fcntl.c
+++ b/sysdeps/unix/sysv/linux/fcntl.c
@@ -20,15 +20,12 @@ 
 #include <stdarg.h>
 #include <errno.h>
 #include <sysdep-cancel.h>
-#include <not-cancel.h>
 
-#ifndef __NR_fcntl64
-# define __NR_fcntl64 __NR_fcntl
-#endif
+#ifndef __OFF_T_MATCHES_OFF64_T
 
-#ifndef FCNTL_ADJUST_CMD
-# define FCNTL_ADJUST_CMD(__cmd) __cmd
-#endif
+# ifndef FCNTL_ADJUST_CMD
+#  define FCNTL_ADJUST_CMD(__cmd) __cmd
+# endif
 
 int
 __libc_fcntl (int fd, int cmd, ...)
@@ -42,13 +39,83 @@  __libc_fcntl (int fd, int cmd, ...)
 
   cmd = FCNTL_ADJUST_CMD (cmd);
 
-  if (cmd == F_SETLKW || cmd == F_SETLKW64)
-    return SYSCALL_CANCEL (fcntl64, fd, cmd, (void *) arg);
-
-  return __fcntl_nocancel_adjusted (fd, cmd, arg);
+  switch (cmd)
+    {
+      case F_SETLKW:
+      case F_SETLKW64:
+	return SYSCALL_CANCEL (fcntl64, fd, cmd, arg);
+      case F_OFD_SETLKW:
+	{
+	  struct flock *flk = (struct flock *) arg;
+	  struct flock64 flk64 =
+	  {
+	    .l_type = flk->l_type,
+	    .l_whence = flk->l_whence,
+	    .l_start = flk->l_start,
+	    .l_len = flk->l_len,
+	    .l_pid = flk->l_pid
+	  };
+	  return SYSCALL_CANCEL (fcntl64, fd, cmd, &flk64);
+	}
+      case F_OFD_GETLK:
+      case F_OFD_SETLK:
+	{
+	  struct flock *flk = (struct flock *) arg;
+	  struct flock64 flk64 =
+	  {
+	    .l_type = flk->l_type,
+	    .l_whence = flk->l_whence,
+	    .l_start = flk->l_start,
+	    .l_len = flk->l_len,
+	    .l_pid = flk->l_pid
+	  };
+	  int ret = INLINE_SYSCALL_CALL (fcntl64, fd, cmd, &flk64);
+	  if (ret == -1)
+	    return -1;
+	  if ((off_t) flk64.l_start != flk64.l_start
+	      || (off_t) flk64.l_len != flk64.l_len)
+	    {
+	      __set_errno (EOVERFLOW);
+	      return -1;
+	    }
+	  flk->l_type = flk64.l_type;
+	  flk->l_whence = flk64.l_whence;
+	  flk->l_start = flk64.l_start;
+	  flk->l_len = flk64.l_len;
+	  flk->l_pid = flk64.l_pid;
+	  return ret;
+	}
+      /* case F_OFD_GETLK:
+         case F_OFD_GETLK64:
+         case F_SETLK64:
+         case F_GETOWN:  */
+      default:
+        return __fcntl64_nocancel_adjusted (fd, cmd, arg);
+    }
 }
 libc_hidden_def (__libc_fcntl)
 
 weak_alias (__libc_fcntl, __fcntl)
 libc_hidden_weak (__fcntl)
+
+# include <shlib-compat.h>
+# if SHLIB_COMPAT(libc, GLIBC_2_0, GLIBC_2_28)
+int
+__old_libc_fcntl64 (int fd, int cmd, ...)
+{
+  va_list ap;
+  void *arg;
+
+  va_start (ap, cmd);
+  arg = va_arg (ap, void *);
+  va_end (ap);
+
+  return __libc_fcntl64 (fd, cmd, arg);
+}
+compat_symbol (libc, __old_libc_fcntl64, fcntl, GLIBC_2_0);
+versioned_symbol (libc, __libc_fcntl, fcntl, GLIBC_2_28);
+# else
 weak_alias (__libc_fcntl, fcntl)
+# endif
+
+#endif /* __OFF_T_MATCHES_OFF64_T  */
diff --git a/sysdeps/unix/sysv/linux/fcntl64.c b/sysdeps/unix/sysv/linux/fcntl64.c
new file mode 100644
index 0000000..f21667a
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/fcntl64.c
@@ -0,0 +1,63 @@ 
+/* Manipulate file descriptor.  Linux LFS version.
+   Copyright (C) 2018 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 fcntl __no_decl_fcntl
+#define __fcntl __no_decl___fcntl
+#include <fcntl.h>
+#undef fcntl
+#undef __fcntl
+#include <stdarg.h>
+#include <errno.h>
+#include <sysdep-cancel.h>
+
+#ifndef __NR_fcntl64
+# define __NR_fcntl64 __NR_fcntl
+#endif
+
+#ifndef FCNTL_ADJUST_CMD
+# define FCNTL_ADJUST_CMD(__cmd) __cmd
+#endif
+
+int
+__libc_fcntl64 (int fd, int cmd, ...)
+{
+  va_list ap;
+  void *arg;
+
+  va_start (ap, cmd);
+  arg = va_arg (ap, void *);
+  va_end (ap);
+
+  cmd = FCNTL_ADJUST_CMD (cmd);
+
+  if (cmd == F_SETLKW || cmd == F_SETLKW64 || cmd == F_OFD_SETLKW)
+    return SYSCALL_CANCEL (fcntl64, fd, cmd, arg);
+
+  return __fcntl64_nocancel_adjusted (fd, cmd, arg);
+}
+libc_hidden_def (__libc_fcntl64)
+weak_alias (__libc_fcntl64, __fcntl64)
+libc_hidden_weak (__fcntl64)
+weak_alias (__libc_fcntl64, fcntl64)
+
+#ifdef __OFF_T_MATCHES_OFF64_T
+weak_alias (__libc_fcntl64, __libc_fcntl)
+weak_alias (__libc_fcntl64, __fcntl)
+weak_alias (__libc_fcntl64, __GI___fcntl)
+weak_alias (__libc_fcntl64, fcntl)
+#endif
diff --git a/sysdeps/unix/sysv/linux/fcntl_nocancel.c b/sysdeps/unix/sysv/linux/fcntl_nocancel.c
index f50e382..dd336b5 100644
--- a/sysdeps/unix/sysv/linux/fcntl_nocancel.c
+++ b/sysdeps/unix/sysv/linux/fcntl_nocancel.c
@@ -31,7 +31,7 @@ 
 #endif
 
 int
-__fcntl_nocancel (int fd, int cmd, ...)
+__fcntl64_nocancel (int fd, int cmd, ...)
 {
   va_list ap;
   void *arg;
@@ -42,12 +42,12 @@  __fcntl_nocancel (int fd, int cmd, ...)
 
   cmd = FCNTL_ADJUST_CMD (cmd);
 
-  return __fcntl_nocancel_adjusted (fd, cmd, arg);
+  return __fcntl64_nocancel_adjusted (fd, cmd, arg);
 }
-hidden_def (__fcntl_nocancel)
+hidden_def (__fcntl64_nocancel)
 
 int
-__fcntl_nocancel_adjusted (int fd, int cmd, void *arg)
+__fcntl64_nocancel_adjusted (int fd, int cmd, void *arg)
 {
   if (cmd == F_GETOWN)
     {
diff --git a/sysdeps/unix/sysv/linux/hppa/libc.abilist b/sysdeps/unix/sysv/linux/hppa/libc.abilist
index d10695b..06b00f7 100644
--- a/sysdeps/unix/sysv/linux/hppa/libc.abilist
+++ b/sysdeps/unix/sysv/linux/hppa/libc.abilist
@@ -1872,6 +1872,8 @@  GLIBC_2.27 wcstof32x F
 GLIBC_2.27 wcstof32x_l F
 GLIBC_2.27 wcstof64 F
 GLIBC_2.27 wcstof64_l F
+GLIBC_2.28 fcntl F
+GLIBC_2.28 fcntl64 F
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
 GLIBC_2.3 __ctype_toupper_loc F
diff --git a/sysdeps/unix/sysv/linux/i386/libc.abilist b/sysdeps/unix/sysv/linux/i386/libc.abilist
index 23092ab..1c1cc00 100644
--- a/sysdeps/unix/sysv/linux/i386/libc.abilist
+++ b/sysdeps/unix/sysv/linux/i386/libc.abilist
@@ -2037,6 +2037,8 @@  GLIBC_2.27 wcstof64 F
 GLIBC_2.27 wcstof64_l F
 GLIBC_2.27 wcstof64x F
 GLIBC_2.27 wcstof64x_l F
+GLIBC_2.28 fcntl F
+GLIBC_2.28 fcntl64 F
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
 GLIBC_2.3 __ctype_toupper_loc F
diff --git a/sysdeps/unix/sysv/linux/ia64/libc.abilist b/sysdeps/unix/sysv/linux/ia64/libc.abilist
index 7bf259e..f6e17a0 100644
--- a/sysdeps/unix/sysv/linux/ia64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/ia64/libc.abilist
@@ -1907,6 +1907,7 @@  GLIBC_2.27 wcstof64 F
 GLIBC_2.27 wcstof64_l F
 GLIBC_2.27 wcstof64x F
 GLIBC_2.27 wcstof64x_l F
+GLIBC_2.28 fcntl64 F
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
 GLIBC_2.3 __ctype_toupper_loc F
diff --git a/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist b/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
index 4673bcd..ee054a6 100644
--- a/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
+++ b/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
@@ -116,6 +116,8 @@  GLIBC_2.27 wcstof32x F
 GLIBC_2.27 wcstof32x_l F
 GLIBC_2.27 wcstof64 F
 GLIBC_2.27 wcstof64_l F
+GLIBC_2.28 fcntl F
+GLIBC_2.28 fcntl64 F
 GLIBC_2.4 _Exit F
 GLIBC_2.4 _IO_2_1_stderr_ D 0x98
 GLIBC_2.4 _IO_2_1_stdin_ D 0x98
diff --git a/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist b/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
index 1f8ac40..227a058 100644
--- a/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
+++ b/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
@@ -1981,6 +1981,8 @@  GLIBC_2.27 wcstof32x F
 GLIBC_2.27 wcstof32x_l F
 GLIBC_2.27 wcstof64 F
 GLIBC_2.27 wcstof64_l F
+GLIBC_2.28 fcntl F
+GLIBC_2.28 fcntl64 F
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
 GLIBC_2.3 __ctype_toupper_loc F
diff --git a/sysdeps/unix/sysv/linux/microblaze/libc.abilist b/sysdeps/unix/sysv/linux/microblaze/libc.abilist
index 09277f5..18781b3 100644
--- a/sysdeps/unix/sysv/linux/microblaze/libc.abilist
+++ b/sysdeps/unix/sysv/linux/microblaze/libc.abilist
@@ -2122,3 +2122,5 @@  GLIBC_2.27 wcstof32x F
 GLIBC_2.27 wcstof32x_l F
 GLIBC_2.27 wcstof64 F
 GLIBC_2.27 wcstof64_l F
+GLIBC_2.28 fcntl F
+GLIBC_2.28 fcntl64 F
diff --git a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
index f562e20..2d86989 100644
--- a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
@@ -1959,6 +1959,8 @@  GLIBC_2.27 wcstof32x F
 GLIBC_2.27 wcstof32x_l F
 GLIBC_2.27 wcstof64 F
 GLIBC_2.27 wcstof64_l F
+GLIBC_2.28 fcntl F
+GLIBC_2.28 fcntl64 F
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
 GLIBC_2.3 __ctype_toupper_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 ceb7388..b8b113e 100644
--- a/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
@@ -1957,6 +1957,8 @@  GLIBC_2.27 wcstof32x F
 GLIBC_2.27 wcstof32x_l F
 GLIBC_2.27 wcstof64 F
 GLIBC_2.27 wcstof64_l F
+GLIBC_2.28 fcntl F
+GLIBC_2.28 fcntl64 F
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
 GLIBC_2.3 __ctype_toupper_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 5765f48..6a3cd13 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
@@ -1965,6 +1965,8 @@  GLIBC_2.27 wcstof64 F
 GLIBC_2.27 wcstof64_l F
 GLIBC_2.27 wcstof64x F
 GLIBC_2.27 wcstof64x_l F
+GLIBC_2.28 fcntl F
+GLIBC_2.28 fcntl64 F
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
 GLIBC_2.3 __ctype_toupper_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 a84bb45..596ec05 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
@@ -1961,6 +1961,7 @@  GLIBC_2.27 wcstof64 F
 GLIBC_2.27 wcstof64_l F
 GLIBC_2.27 wcstof64x F
 GLIBC_2.27 wcstof64x_l F
+GLIBC_2.28 fcntl64 F
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
 GLIBC_2.3 __ctype_toupper_loc F
diff --git a/sysdeps/unix/sysv/linux/nios2/libc.abilist b/sysdeps/unix/sysv/linux/nios2/libc.abilist
index e432959..8da18ee 100644
--- a/sysdeps/unix/sysv/linux/nios2/libc.abilist
+++ b/sysdeps/unix/sysv/linux/nios2/libc.abilist
@@ -2163,3 +2163,5 @@  GLIBC_2.27 wcstof32x F
 GLIBC_2.27 wcstof32x_l F
 GLIBC_2.27 wcstof64 F
 GLIBC_2.27 wcstof64_l F
+GLIBC_2.28 fcntl F
+GLIBC_2.28 fcntl64 F
diff --git a/sysdeps/unix/sysv/linux/not-cancel.h b/sysdeps/unix/sysv/linux/not-cancel.h
index 0b5c955..09de92d 100644
--- a/sysdeps/unix/sysv/linux/not-cancel.h
+++ b/sysdeps/unix/sysv/linux/not-cancel.h
@@ -76,7 +76,7 @@  __typeof (pause) __pause_nocancel;
 __typeof (__nanosleep) __nanosleep_nocancel;
 
 /* Uncancelable fcntl.  */
-__typeof (__fcntl) __fcntl_nocancel;
+__typeof (__fcntl) __fcntl64_nocancel;
 
 #if IS_IN (libc) || IS_IN (rtld)
 hidden_proto (__open_nocancel)
@@ -89,7 +89,7 @@  hidden_proto (__close_nocancel)
 hidden_proto (__waitpid_nocancel)
 hidden_proto (__pause_nocancel)
 hidden_proto (__nanosleep_nocancel)
-hidden_proto (__fcntl_nocancel)
+hidden_proto (__fcntl64_nocancel)
 #endif
 
 #endif /* NOT_CANCEL_H  */
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
index a5f2b23..555751e 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
@@ -1985,6 +1985,8 @@  GLIBC_2.27 wcstof32x F
 GLIBC_2.27 wcstof32x_l F
 GLIBC_2.27 wcstof64 F
 GLIBC_2.27 wcstof64_l F
+GLIBC_2.28 fcntl F
+GLIBC_2.28 fcntl64 F
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
 GLIBC_2.3 __ctype_toupper_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 e4cbe36..80324e4 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
@@ -1989,6 +1989,8 @@  GLIBC_2.27 wcstof32x F
 GLIBC_2.27 wcstof32x_l F
 GLIBC_2.27 wcstof64 F
 GLIBC_2.27 wcstof64_l F
+GLIBC_2.28 fcntl F
+GLIBC_2.28 fcntl64 F
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
 GLIBC_2.3 __ctype_toupper_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 9869feb..97b1d35 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist
@@ -2221,3 +2221,4 @@  GLIBC_2.27 wcstof64 F
 GLIBC_2.27 wcstof64_l F
 GLIBC_2.27 wcstof64x F
 GLIBC_2.27 wcstof64x_l F
+GLIBC_2.28 fcntl64 F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist
index e526dc4..15be314 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist
@@ -116,6 +116,7 @@  GLIBC_2.27 wcstof32x F
 GLIBC_2.27 wcstof32x_l F
 GLIBC_2.27 wcstof64 F
 GLIBC_2.27 wcstof64_l F
+GLIBC_2.28 fcntl64 F
 GLIBC_2.3 _Exit F
 GLIBC_2.3 _IO_2_1_stderr_ D 0xe0
 GLIBC_2.3 _IO_2_1_stdin_ D 0xe0
diff --git a/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist b/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
index e6319ee..436b992 100644
--- a/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
@@ -2093,3 +2093,4 @@  GLIBC_2.27 xdrstdio_create F
 GLIBC_2.27 xencrypt F
 GLIBC_2.27 xprt_register F
 GLIBC_2.27 xprt_unregister F
+GLIBC_2.28 fcntl64 F
diff --git a/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist b/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
index 41cdda0..f66715f 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
@@ -1994,6 +1994,8 @@  GLIBC_2.27 wcstof64 F
 GLIBC_2.27 wcstof64_l F
 GLIBC_2.27 wcstof64x F
 GLIBC_2.27 wcstof64x_l F
+GLIBC_2.28 fcntl F
+GLIBC_2.28 fcntl64 F
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
 GLIBC_2.3 __ctype_toupper_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 8a756cf..bd62428 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
@@ -1900,6 +1900,7 @@  GLIBC_2.27 wcstof64 F
 GLIBC_2.27 wcstof64_l F
 GLIBC_2.27 wcstof64x F
 GLIBC_2.27 wcstof64x_l F
+GLIBC_2.28 fcntl64 F
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
 GLIBC_2.3 __ctype_toupper_loc F
diff --git a/sysdeps/unix/sysv/linux/sh/libc.abilist b/sysdeps/unix/sysv/linux/sh/libc.abilist
index 999bddd..f2f070f 100644
--- a/sysdeps/unix/sysv/linux/sh/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sh/libc.abilist
@@ -1876,6 +1876,8 @@  GLIBC_2.27 wcstof32x F
 GLIBC_2.27 wcstof32x_l F
 GLIBC_2.27 wcstof64 F
 GLIBC_2.27 wcstof64_l F
+GLIBC_2.28 fcntl F
+GLIBC_2.28 fcntl64 F
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
 GLIBC_2.3 __ctype_toupper_loc F
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist b/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
index 7c4296f..265087f 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
@@ -1988,6 +1988,8 @@  GLIBC_2.27 wcstof64 F
 GLIBC_2.27 wcstof64_l F
 GLIBC_2.27 wcstof64x F
 GLIBC_2.27 wcstof64x_l F
+GLIBC_2.28 fcntl F
+GLIBC_2.28 fcntl64 F
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
 GLIBC_2.3 __ctype_toupper_loc F
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist b/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
index dafe9d7..16a6981 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
@@ -1930,6 +1930,7 @@  GLIBC_2.27 wcstof64 F
 GLIBC_2.27 wcstof64_l F
 GLIBC_2.27 wcstof64x F
 GLIBC_2.27 wcstof64x_l F
+GLIBC_2.28 fcntl64 F
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
 GLIBC_2.3 __ctype_toupper_loc F
diff --git a/sysdeps/unix/sysv/linux/tst-ofdlocks.c b/sysdeps/unix/sysv/linux/tst-ofdlocks.c
new file mode 100644
index 0000000..3ddd93d
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/tst-ofdlocks.c
@@ -0,0 +1,76 @@ 
+/* Check non representable region in non-LFS mode (BZ #20251)
+   Copyright (C) 2018 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License
+   as published by the Free Software Foundation; either version 2
+   of the License, or (at your option) any later version.
+
+   This program 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <unistd.h>
+#include <fcntl.h>
+#include <stdint.h>
+#include <errno.h>
+
+#include <support/temp_file.h>
+#include <support/check.h>
+
+static char *temp_filename;
+static int temp_fd;
+
+static void
+do_prepare (int argc, char **argv)
+{
+  temp_fd = create_temp_file ("tst-ofdlocks.", &temp_filename);
+  TEST_VERIFY_EXIT (temp_fd != -1);
+}
+
+#define PREPARE do_prepare
+
+static int
+do_test (void)
+{
+  /* It first allocates a open file description lock range which can not
+     be represented in a 32 bit struct flock.   */
+  struct flock64 lck64 = {
+    .l_type   = F_WRLCK,
+    .l_whence = SEEK_SET,
+    .l_start  = (off64_t)INT32_MAX + 1024,
+    .l_len    = 1024,
+  };
+  TEST_VERIFY_EXIT (fcntl64 (temp_fd, F_OFD_SETLKW, &lck64) == 0);
+
+  /* Open file description locks placed through the same open file description
+     (either by same file descriptor or a duplicated one created by fork,
+     dup, fcntl F_DUPFD, etc.) overwrites then old lock.  To force a
+     conflicting lock combinatioin, it creates a new file descriptor.  */
+  int fd = open64 (temp_filename, O_RDWR, 0666);
+  TEST_VERIFY_EXIT (fd != -1);
+
+  /* It tries then to allocate another open file descriptior with a valid
+     non-LFS bits struct flock but which will result in a conflicted region
+     which can not be represented in a non-LFS struct flock.  */
+  struct flock lck = {
+    .l_type   = F_WRLCK,
+    .l_whence = SEEK_SET,
+    .l_start  = INT32_MAX - 1024,
+    .l_len    = 4 * 1024,
+  };
+  int r = fcntl (fd, F_OFD_GETLK, &lck);
+  if (sizeof (off_t) != sizeof (off64_t))
+    TEST_VERIFY (r == -1 && errno == EOVERFLOW);
+  else
+    TEST_VERIFY (r == 0);
+
+  return 0;
+}
+
+#include <support/test-driver.c>
diff --git a/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist b/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
index f72d494..fa8c198 100644
--- a/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
@@ -1888,6 +1888,7 @@  GLIBC_2.27 wcstof64 F
 GLIBC_2.27 wcstof64_l F
 GLIBC_2.27 wcstof64x F
 GLIBC_2.27 wcstof64x_l F
+GLIBC_2.28 fcntl64 F
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
 GLIBC_2.3 __ctype_toupper_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 96c9fa0..2536971 100644
--- a/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
@@ -2139,3 +2139,4 @@  GLIBC_2.27 wcstof64 F
 GLIBC_2.27 wcstof64_l F
 GLIBC_2.27 wcstof64x F
 GLIBC_2.27 wcstof64x_l F
+GLIBC_2.28 fcntl64 F