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-rw-r--r--NEWS4
-rw-r--r--sysdeps/unix/sysv/linux/Makefile14
-rw-r--r--sysdeps/unix/sysv/linux/Versions3
-rw-r--r--sysdeps/unix/sysv/linux/aarch64/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/alpha/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/arc/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/arm/le/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/bits/fcntl-linux.h22
-rw-r--r--sysdeps/unix/sysv/linux/bits/openat2.h61
-rw-r--r--sysdeps/unix/sysv/linux/csky/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/hppa/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/i386/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/loongarch/lp64/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/microblaze/be/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/nios2/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/openat2.c29
-rw-r--r--sysdeps/unix/sysv/linux/or1k/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/sh/le/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist1
-rwxr-xr-xsysdeps/unix/sysv/linux/tst-openat2-consts.py63
-rw-r--r--sysdeps/unix/sysv/linux/tst-openat2.c259
-rw-r--r--sysdeps/unix/sysv/linux/x86_64/64/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist1
35 files changed, 482 insertions, 0 deletions
diff --git a/NEWS b/NEWS
index cf6078cf20..eaaa02cb4e 100644
--- a/NEWS
+++ b/NEWS
@@ -26,6 +26,10 @@ Major new features:
   more extensive verification tests for AT_SECURE programs and not meant to
   be a security feature.
 
+* On Linux, the openat2 function has been added.  It is an extension of
+  openat and provides a superset of its functionality.  It is supported only
+  in LFS mode and as other open like it is a cancellable entrypoint.
+
 Deprecated and removed features, and other changes affecting compatibility:
 
 * Architectures which use a 32-bit seconds-since-epoch field in struct
diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile
index 415aa1f14d..fcb9b810b5 100644
--- a/sysdeps/unix/sysv/linux/Makefile
+++ b/sysdeps/unix/sysv/linux/Makefile
@@ -133,6 +133,7 @@ sysdep_headers += \
   bits/mman-linux.h \
   bits/mman-map-flags-generic.h \
   bits/mman-shared.h \
+  bits/openat2.h \
   bits/procfs-extra.h \
   bits/procfs-id.h \
   bits/procfs-prregset.h \
@@ -593,6 +594,7 @@ sysdep_routines += \
   open_nocancel \
   openat64_nocancel \
   openat_nocancel \
+  openat2 \
   pread64_nocancel \
   read_nocancel \
   stat_t64_cp \
@@ -607,11 +609,23 @@ sysdep_headers += \
   # sysdep_headers
 
 tests += \
+  tst-openat2 \
   tst-fallocate \
   tst-fallocate64 \
   tst-getcwd-smallbuff \
   tst-o_path-locks \
   # tests
+
+tests-special += \
+  $(objpfx)tst-openat2-consts.out \
+  # tests-special
+$(objpfx)tst-openat2-consts.out: ../sysdeps/unix/sysv/linux/tst-openat2-consts.py
+	$(sysdeps-linux-python) \
+	  ../sysdeps/unix/sysv/linux/tst-openat2-consts.py \
+	    $(sysdeps-linux-python-cc) \
+	  < /dev/null > $@ 2>&1; $(evaluate-test)
+$(objpfx)tst-openat2-consts.out: $(sysdeps-linux-python-deps)
+
 endif
 
 ifeq ($(subdir),elf)
diff --git a/sysdeps/unix/sysv/linux/Versions b/sysdeps/unix/sysv/linux/Versions
index 268ba1b6ac..65da2b617a 100644
--- a/sysdeps/unix/sysv/linux/Versions
+++ b/sysdeps/unix/sysv/linux/Versions
@@ -328,6 +328,9 @@ libc {
     posix_spawnattr_getcgroup_np;
     posix_spawnattr_setcgroup_np;
   }
+  GLIBC_2.40 {
+    openat2;
+  }
   GLIBC_PRIVATE {
     # functions used in other libraries
     __syscall_rt_sigqueueinfo;
diff --git a/sysdeps/unix/sysv/linux/aarch64/libc.abilist b/sysdeps/unix/sysv/linux/aarch64/libc.abilist
index 68eeca1c08..0b9bd8ae62 100644
--- a/sysdeps/unix/sysv/linux/aarch64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/aarch64/libc.abilist
@@ -2748,3 +2748,4 @@ GLIBC_2.39 stdc_trailing_zeros_ui F
 GLIBC_2.39 stdc_trailing_zeros_ul F
 GLIBC_2.39 stdc_trailing_zeros_ull F
 GLIBC_2.39 stdc_trailing_zeros_us F
+GLIBC_2.40 openat2 F
diff --git a/sysdeps/unix/sysv/linux/alpha/libc.abilist b/sysdeps/unix/sysv/linux/alpha/libc.abilist
index 34c187b721..c0bd27d617 100644
--- a/sysdeps/unix/sysv/linux/alpha/libc.abilist
+++ b/sysdeps/unix/sysv/linux/alpha/libc.abilist
@@ -3095,6 +3095,7 @@ GLIBC_2.4 wcstold F
 GLIBC_2.4 wcstold_l F
 GLIBC_2.4 wprintf F
 GLIBC_2.4 wscanf F
+GLIBC_2.40 openat2 F
 GLIBC_2.5 __readlinkat_chk F
 GLIBC_2.5 inet6_opt_append F
 GLIBC_2.5 inet6_opt_find F
diff --git a/sysdeps/unix/sysv/linux/arc/libc.abilist b/sysdeps/unix/sysv/linux/arc/libc.abilist
index 916c18ea94..965438e7a7 100644
--- a/sysdeps/unix/sysv/linux/arc/libc.abilist
+++ b/sysdeps/unix/sysv/linux/arc/libc.abilist
@@ -2509,3 +2509,4 @@ GLIBC_2.39 stdc_trailing_zeros_ui F
 GLIBC_2.39 stdc_trailing_zeros_ul F
 GLIBC_2.39 stdc_trailing_zeros_ull F
 GLIBC_2.39 stdc_trailing_zeros_us F
+GLIBC_2.40 openat2 F
diff --git a/sysdeps/unix/sysv/linux/arm/le/libc.abilist b/sysdeps/unix/sysv/linux/arm/le/libc.abilist
index 1cdbc983e1..70fd425869 100644
--- a/sysdeps/unix/sysv/linux/arm/le/libc.abilist
+++ b/sysdeps/unix/sysv/linux/arm/le/libc.abilist
@@ -2798,6 +2798,7 @@ GLIBC_2.4 xdrstdio_create F
 GLIBC_2.4 xencrypt F
 GLIBC_2.4 xprt_register F
 GLIBC_2.4 xprt_unregister F
+GLIBC_2.40 openat2 F
 GLIBC_2.5 __readlinkat_chk F
 GLIBC_2.5 inet6_opt_append F
 GLIBC_2.5 inet6_opt_find F
diff --git a/sysdeps/unix/sysv/linux/bits/fcntl-linux.h b/sysdeps/unix/sysv/linux/bits/fcntl-linux.h
index 628612b885..279aa2b8eb 100644
--- a/sysdeps/unix/sysv/linux/bits/fcntl-linux.h
+++ b/sysdeps/unix/sysv/linux/bits/fcntl-linux.h
@@ -451,6 +451,28 @@ extern int name_to_handle_at (int __dfd, const char *__name,
 extern int open_by_handle_at (int __mountdirfd, struct file_handle *__handle,
 			      int __flags);
 
+#ifdef __has_include
+# if __has_include ("linux/openat2.h")
+#  include "linux/openat2.h"
+#  define __glibc_has_open_how 1
+# endif
+#endif
+
+#include <bits/openat2.h>
+
+/* Similar to `openat' but the arguments are packed on HOW with the size
+   USIZE.  If flags and mode from HOW are non-zero, then openat2 operates
+   like openat.
+
+   Unlike openat2, unknown or invalid flags result in an error (EINVAL),
+   rather than being ignored.  The mode must be zero unless one O_CREAT
+   or O_TMPFILE are set.
+
+   The kernel does not support legacy non-LFS interface.  */
+extern int openat2 (int __dfd, const char *__filename, struct open_how *__how,
+		    size_t __usize)
+     __nonnull ((2, 3));
+
 #endif	/* use GNU */
 
 __END_DECLS
diff --git a/sysdeps/unix/sysv/linux/bits/openat2.h b/sysdeps/unix/sysv/linux/bits/openat2.h
new file mode 100644
index 0000000000..a07984dace
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/bits/openat2.h
@@ -0,0 +1,61 @@
+/* openat2 definition.  Linux specific.
+   Copyright (C) 2024 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
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef	_FCNTL_H
+# error "Never use <bits/openat2.h> directly; include <fcntl.h> instead."
+#endif
+
+#ifndef __glibc_has_open_how
+/* Arguments for how openat2 should open the target path.  */
+struct open_how
+{
+  __uint64_t flags;
+  __uint64_t mode;
+  __uint64_t resolve;
+};
+#endif
+
+/* how->resolve flags for openat2. */
+#ifndef RESOLVE_NO_XDEV
+# define RESOLVE_NO_XDEV	0x01 /* Block mount-point crossings
+					(includes bind-mounts).  */
+#endif
+#ifndef RESOLVE_NO_MAGICLINKS
+# define RESOLVE_NO_MAGICLINKS	0x02 /* Block traversal through procfs-style
+					"magic-links".  */
+#endif
+#ifndef RESOLVE_NO_SYMLINKS
+# define RESOLVE_NO_SYMLINKS	0x04 /* Block traversal through all symlinks
+					(implies OEXT_NO_MAGICLINKS).  */
+#endif
+#ifndef RESOLVE_BENEATH
+# define RESOLVE_BENEATH	0x08 /* Block "lexical" trickery like
+					"..", symlinks, and absolute
+					paths which escape the dirfd.  */
+#endif
+#ifndef RESOLVE_IN_ROOT
+# define RESOLVE_IN_ROOT	0x10 /* Make all jumps to "/" and ".."
+					be scoped inside the dirfd
+					(similar to chroot).  */
+#endif
+#ifndef RESOLVE_CACHED
+# define RESOLVE_CACHED		0x20 /* Only complete if resolution can be
+					completed through cached lookup. May
+					return -EAGAIN if that's not
+					possible.  */
+#endif
diff --git a/sysdeps/unix/sysv/linux/csky/libc.abilist b/sysdeps/unix/sysv/linux/csky/libc.abilist
index 96d45961e2..c81ea43dc1 100644
--- a/sysdeps/unix/sysv/linux/csky/libc.abilist
+++ b/sysdeps/unix/sysv/linux/csky/libc.abilist
@@ -2785,3 +2785,4 @@ GLIBC_2.39 stdc_trailing_zeros_ui F
 GLIBC_2.39 stdc_trailing_zeros_ul F
 GLIBC_2.39 stdc_trailing_zeros_ull F
 GLIBC_2.39 stdc_trailing_zeros_us F
+GLIBC_2.40 openat2 F
diff --git a/sysdeps/unix/sysv/linux/hppa/libc.abilist b/sysdeps/unix/sysv/linux/hppa/libc.abilist
index fbcd60c2b3..23eec25d8a 100644
--- a/sysdeps/unix/sysv/linux/hppa/libc.abilist
+++ b/sysdeps/unix/sysv/linux/hppa/libc.abilist
@@ -2821,6 +2821,7 @@ GLIBC_2.4 sys_errlist D 0x400
 GLIBC_2.4 sys_nerr D 0x4
 GLIBC_2.4 unlinkat F
 GLIBC_2.4 unshare F
+GLIBC_2.40 openat2 F
 GLIBC_2.5 __readlinkat_chk F
 GLIBC_2.5 inet6_opt_append F
 GLIBC_2.5 inet6_opt_find F
diff --git a/sysdeps/unix/sysv/linux/i386/libc.abilist b/sysdeps/unix/sysv/linux/i386/libc.abilist
index c989b433c0..4ce2afb147 100644
--- a/sysdeps/unix/sysv/linux/i386/libc.abilist
+++ b/sysdeps/unix/sysv/linux/i386/libc.abilist
@@ -3005,6 +3005,7 @@ GLIBC_2.4 sys_errlist D 0x210
 GLIBC_2.4 sys_nerr D 0x4
 GLIBC_2.4 unlinkat F
 GLIBC_2.4 unshare F
+GLIBC_2.40 openat2 F
 GLIBC_2.5 __readlinkat_chk F
 GLIBC_2.5 inet6_opt_append F
 GLIBC_2.5 inet6_opt_find F
diff --git a/sysdeps/unix/sysv/linux/loongarch/lp64/libc.abilist b/sysdeps/unix/sysv/linux/loongarch/lp64/libc.abilist
index 0023ec1fa1..be76251b28 100644
--- a/sysdeps/unix/sysv/linux/loongarch/lp64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/loongarch/lp64/libc.abilist
@@ -2269,3 +2269,4 @@ GLIBC_2.39 stdc_trailing_zeros_ui F
 GLIBC_2.39 stdc_trailing_zeros_ul F
 GLIBC_2.39 stdc_trailing_zeros_ull F
 GLIBC_2.39 stdc_trailing_zeros_us F
+GLIBC_2.40 openat2 F
diff --git a/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist b/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
index 439796d693..39645248af 100644
--- a/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
+++ b/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
@@ -2948,6 +2948,7 @@ GLIBC_2.4 sys_errlist D 0x210
 GLIBC_2.4 sys_nerr D 0x4
 GLIBC_2.4 unlinkat F
 GLIBC_2.4 unshare F
+GLIBC_2.40 openat2 F
 GLIBC_2.5 __readlinkat_chk F
 GLIBC_2.5 inet6_opt_append F
 GLIBC_2.5 inet6_opt_find F
diff --git a/sysdeps/unix/sysv/linux/microblaze/be/libc.abilist b/sysdeps/unix/sysv/linux/microblaze/be/libc.abilist
index 1069d3252c..2f917724de 100644
--- a/sysdeps/unix/sysv/linux/microblaze/be/libc.abilist
+++ b/sysdeps/unix/sysv/linux/microblaze/be/libc.abilist
@@ -2834,3 +2834,4 @@ GLIBC_2.39 stdc_trailing_zeros_ui F
 GLIBC_2.39 stdc_trailing_zeros_ul F
 GLIBC_2.39 stdc_trailing_zeros_ull F
 GLIBC_2.39 stdc_trailing_zeros_us F
+GLIBC_2.40 openat2 F
diff --git a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
index 799e508950..ae5b95bc76 100644
--- a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
@@ -2909,6 +2909,7 @@ GLIBC_2.4 renameat F
 GLIBC_2.4 symlinkat F
 GLIBC_2.4 unlinkat F
 GLIBC_2.4 unshare F
+GLIBC_2.40 openat2 F
 GLIBC_2.5 __readlinkat_chk F
 GLIBC_2.5 inet6_opt_append F
 GLIBC_2.5 inet6_opt_find F
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
index 03d9655f26..5dc2996fcc 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
@@ -2915,6 +2915,7 @@ GLIBC_2.4 renameat F
 GLIBC_2.4 symlinkat F
 GLIBC_2.4 unlinkat F
 GLIBC_2.4 unshare F
+GLIBC_2.40 openat2 F
 GLIBC_2.5 __readlinkat_chk F
 GLIBC_2.5 inet6_opt_append F
 GLIBC_2.5 inet6_opt_find F
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
index 05e402ed30..865dc5e7f1 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
@@ -2817,6 +2817,7 @@ GLIBC_2.4 renameat F
 GLIBC_2.4 symlinkat F
 GLIBC_2.4 unlinkat F
 GLIBC_2.4 unshare F
+GLIBC_2.40 openat2 F
 GLIBC_2.5 __readlinkat_chk F
 GLIBC_2.5 inet6_opt_append F
 GLIBC_2.5 inet6_opt_find F
diff --git a/sysdeps/unix/sysv/linux/nios2/libc.abilist b/sysdeps/unix/sysv/linux/nios2/libc.abilist
index 3aa81766aa..12775fdad5 100644
--- a/sysdeps/unix/sysv/linux/nios2/libc.abilist
+++ b/sysdeps/unix/sysv/linux/nios2/libc.abilist
@@ -2873,3 +2873,4 @@ GLIBC_2.39 stdc_trailing_zeros_ui F
 GLIBC_2.39 stdc_trailing_zeros_ul F
 GLIBC_2.39 stdc_trailing_zeros_ull F
 GLIBC_2.39 stdc_trailing_zeros_us F
+GLIBC_2.40 openat2 F
diff --git a/sysdeps/unix/sysv/linux/openat2.c b/sysdeps/unix/sysv/linux/openat2.c
new file mode 100644
index 0000000000..a2b134bab0
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/openat2.c
@@ -0,0 +1,29 @@
+/* Linux openat2 syscall implementation.
+   Copyright (C) 2024 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
+   <https://www.gnu.org/licenses/>.  */
+
+#include <fcntl.h>
+#include <bits/openat2.h>
+#include <sysdep-cancel.h>
+
+int
+__openat2 (int dfd, const char *filename, struct open_how *how,
+	   size_t usize)
+{
+  return SYSCALL_CANCEL (openat2, dfd, filename, how, usize);
+}
+weak_alias (__openat2, openat2)
diff --git a/sysdeps/unix/sysv/linux/or1k/libc.abilist b/sysdeps/unix/sysv/linux/or1k/libc.abilist
index c40c843aaf..2835436011 100644
--- a/sysdeps/unix/sysv/linux/or1k/libc.abilist
+++ b/sysdeps/unix/sysv/linux/or1k/libc.abilist
@@ -2255,3 +2255,4 @@ GLIBC_2.39 stdc_trailing_zeros_ui F
 GLIBC_2.39 stdc_trailing_zeros_ul F
 GLIBC_2.39 stdc_trailing_zeros_ull F
 GLIBC_2.39 stdc_trailing_zeros_us F
+GLIBC_2.40 openat2 F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
index 9714305608..3b70a56944 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
@@ -3138,6 +3138,7 @@ GLIBC_2.4 wcstold F
 GLIBC_2.4 wcstold_l F
 GLIBC_2.4 wprintf F
 GLIBC_2.4 wscanf F
+GLIBC_2.40 openat2 F
 GLIBC_2.5 __readlinkat_chk F
 GLIBC_2.5 inet6_opt_append F
 GLIBC_2.5 inet6_opt_find F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist
index cfc2ebd3ec..10fc3c89dc 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist
@@ -2892,6 +2892,7 @@ GLIBC_2.4 wcstold F
 GLIBC_2.4 wcstold_l F
 GLIBC_2.4 wprintf F
 GLIBC_2.4 wscanf F
+GLIBC_2.40 openat2 F
 GLIBC_2.5 __readlinkat_chk F
 GLIBC_2.5 inet6_opt_append F
 GLIBC_2.5 inet6_opt_find F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist
index 8c9efc5a16..713fa1d1c8 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist
@@ -2968,3 +2968,4 @@ GLIBC_2.39 stdc_trailing_zeros_ui F
 GLIBC_2.39 stdc_trailing_zeros_ul F
 GLIBC_2.39 stdc_trailing_zeros_ull F
 GLIBC_2.39 stdc_trailing_zeros_us F
+GLIBC_2.40 openat2 F
diff --git a/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist b/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist
index 6397a9cb91..550ba877ef 100644
--- a/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist
@@ -2512,3 +2512,4 @@ GLIBC_2.39 stdc_trailing_zeros_ul F
 GLIBC_2.39 stdc_trailing_zeros_ull F
 GLIBC_2.39 stdc_trailing_zeros_us F
 GLIBC_2.40 __riscv_hwprobe F
+GLIBC_2.40 openat2 F
diff --git a/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist b/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
index 71bbf94f66..8bf9f309b7 100644
--- a/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
@@ -2712,3 +2712,4 @@ GLIBC_2.39 stdc_trailing_zeros_ul F
 GLIBC_2.39 stdc_trailing_zeros_ull F
 GLIBC_2.39 stdc_trailing_zeros_us F
 GLIBC_2.40 __riscv_hwprobe F
+GLIBC_2.40 openat2 F
diff --git a/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist b/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
index a7467e2850..08bc3d6f8b 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
@@ -3136,6 +3136,7 @@ GLIBC_2.4 wcstold F
 GLIBC_2.4 wcstold_l F
 GLIBC_2.4 wprintf F
 GLIBC_2.4 wscanf F
+GLIBC_2.40 openat2 F
 GLIBC_2.5 __readlinkat_chk F
 GLIBC_2.5 inet6_opt_append F
 GLIBC_2.5 inet6_opt_find F
diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist b/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
index fd1cb2972d..e25afff581 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
@@ -2929,6 +2929,7 @@ GLIBC_2.4 wcstold F
 GLIBC_2.4 wcstold_l F
 GLIBC_2.4 wprintf F
 GLIBC_2.4 wscanf F
+GLIBC_2.40 openat2 F
 GLIBC_2.5 __readlinkat_chk F
 GLIBC_2.5 inet6_opt_append F
 GLIBC_2.5 inet6_opt_find F
diff --git a/sysdeps/unix/sysv/linux/sh/le/libc.abilist b/sysdeps/unix/sysv/linux/sh/le/libc.abilist
index 449d92bbc5..bdd9c600f0 100644
--- a/sysdeps/unix/sysv/linux/sh/le/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sh/le/libc.abilist
@@ -2825,6 +2825,7 @@ GLIBC_2.4 sys_errlist D 0x210
 GLIBC_2.4 sys_nerr D 0x4
 GLIBC_2.4 unlinkat F
 GLIBC_2.4 unshare F
+GLIBC_2.40 openat2 F
 GLIBC_2.5 __readlinkat_chk F
 GLIBC_2.5 inet6_opt_append F
 GLIBC_2.5 inet6_opt_find F
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist b/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
index e615be759a..b20dd43d47 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
@@ -3157,6 +3157,7 @@ GLIBC_2.4 wcstold F
 GLIBC_2.4 wcstold_l F
 GLIBC_2.4 wprintf F
 GLIBC_2.4 wscanf F
+GLIBC_2.40 openat2 F
 GLIBC_2.5 __readlinkat_chk F
 GLIBC_2.5 inet6_opt_append F
 GLIBC_2.5 inet6_opt_find F
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist b/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
index bd36431dd7..19981aa981 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
@@ -2793,6 +2793,7 @@ GLIBC_2.4 sys_errlist D 0x430
 GLIBC_2.4 sys_nerr D 0x4
 GLIBC_2.4 unlinkat F
 GLIBC_2.4 unshare F
+GLIBC_2.40 openat2 F
 GLIBC_2.5 __readlinkat_chk F
 GLIBC_2.5 inet6_opt_append F
 GLIBC_2.5 inet6_opt_find F
diff --git a/sysdeps/unix/sysv/linux/tst-openat2-consts.py b/sysdeps/unix/sysv/linux/tst-openat2-consts.py
new file mode 100755
index 0000000000..1623fafd94
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/tst-openat2-consts.py
@@ -0,0 +1,63 @@
+#!/usr/bin/python3
+# Test that glibc's sys/openat2.h constants match the kernel's.
+# Copyright (C) 2024 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
+# <https://www.gnu.org/licenses/>.
+
+import argparse
+import sys
+
+import glibcextract
+import glibcsyscalls
+
+
+def main():
+    """The main entry point."""
+    parser = argparse.ArgumentParser(
+        description="Test that glibc's sys/openat2.h constants "
+        "match the kernel's.")
+    parser.add_argument('--cc', metavar='CC',
+                        help='C compiler (including options) to use')
+    args = parser.parse_args()
+
+    if glibcextract.compile_c_snippet(
+            '#include <linux/openat2.h>',
+            args.cc).returncode != 0:
+        sys.exit (77)
+
+    linux_version_headers = glibcsyscalls.linux_kernel_version(args.cc)
+    # Constants in glibc were updated to match Linux v6.8.  When glibc
+    # constants are updated this value should be updated to match the
+    # released kernel version from which the constants were taken.
+    linux_version_glibc = (6, 8)
+    def check(cte, exclude=None):
+        return glibcextract.compare_macro_consts(
+                '#define _FCNTL_H\n'
+                '#include <stdint.h>\n'
+                '#include <bits/openat2.h>\n',
+                '#include <asm/fcntl.h>\n'
+                '#include <linux/openat2.h>\n',
+                args.cc,
+                cte,
+                exclude,
+                linux_version_glibc > linux_version_headers,
+                linux_version_headers > linux_version_glibc)
+
+    status = check('RESOLVE.*')
+    sys.exit(status)
+
+if __name__ == '__main__':
+    main()
diff --git a/sysdeps/unix/sysv/linux/tst-openat2.c b/sysdeps/unix/sysv/linux/tst-openat2.c
new file mode 100644
index 0000000000..6936b9fcef
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/tst-openat2.c
@@ -0,0 +1,259 @@
+/* Linux openat2 tests.
+   Copyright (C) 2024 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
+   <https://www.gnu.org/licenses/>.  */
+
+/* openat2 is only support in LFS mode.  */
+#define _FILE_OFFSET_BITS 64
+
+#include <array_length.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdint.h>
+#include <support/check.h>
+#include <support/temp_file.h>
+#include <support/xunistd.h>
+
+static int dir_fd;
+
+static void
+do_prepare (int argc, char *argv[])
+{
+  char *temp_dir = support_create_temp_directory ("tst-openat2");
+  dir_fd = xopen (temp_dir, O_RDONLY | O_DIRECTORY, 0);
+}
+#define PREPARE do_prepare
+
+static int
+do_test_struct (void)
+{
+  static struct struct_test
+  {
+    struct open_how_ext
+    {
+      struct open_how inner;
+      int extra1;
+      int extra2;
+      int extra3;
+    } arg;
+    size_t size;
+    int err;
+  } tests[] =
+  {
+    {
+      /* Zero size.  */
+      .arg.inner.flags = O_RDONLY,
+      .size = 0,
+      .err = EINVAL,
+    },
+    {
+      /* Normal struct.  */
+      .arg.inner.flags = O_RDONLY,
+      .size = sizeof (struct open_how),
+    },
+    {
+      /* Larger struct, zeroed out the unused values.  */
+      .arg.inner.flags = O_RDONLY,
+      .size = sizeof (struct open_how_ext),
+    },
+    {
+      /* Larger struct, non-zeroed out the unused values.  */
+      .arg.inner.flags = O_RDONLY,
+      .arg.extra1 = 0xdeadbeef,
+      .size = sizeof (struct open_how_ext),
+      .err = E2BIG,
+    },
+    {
+      /* Larger struct, non-zeroed out the unused values.  */
+      .arg.inner.flags = O_RDONLY,
+      .arg.extra2 = 0xdeadbeef,
+      .size = sizeof (struct open_how_ext),
+      .err = E2BIG,
+    },
+  };
+
+  for (struct struct_test *t = tests; t != array_end (tests); t++)
+    {
+      int fd = openat2 (AT_FDCWD, ".", (struct open_how *) &t->arg, t->size);
+      if (fd == -1 && errno == ENOSYS)
+	FAIL_UNSUPPORTED ("openat2 is not supported by the kernel");
+
+      if (t->err != 0)
+	{
+	  TEST_COMPARE (fd, -1);
+	  TEST_COMPARE (errno, t->err);
+	}
+      else
+	TEST_VERIFY (fd >= 0);
+    }
+
+  return 0;
+}
+
+static int
+do_test_flags (void)
+{
+  static struct flag_test
+  {
+    struct open_how how;
+    int err;
+  } tests[] =
+  {
+    /* O_TMPFILE is incompatible with O_PATH and O_CREAT.  */
+    { .how.flags = O_TMPFILE | O_PATH | O_RDWR, .err = EINVAL },
+    { .how.flags = O_TMPFILE | O_CREAT | O_RDWR, .err = EINVAL },
+
+    /* O_PATH only permits certain other flags to be set ...  */
+    { .how.flags = O_PATH | O_CLOEXEC },
+    { .how.flags = O_PATH | O_DIRECTORY },
+    { .how.flags = O_PATH | O_NOFOLLOW },
+    /* ... and others are absolutely not permitted. */
+    { .how.flags = O_PATH | O_RDWR, .err = EINVAL },
+    { .how.flags = O_PATH | O_CREAT, .err = EINVAL },
+    { .how.flags = O_PATH | O_EXCL, .err = EINVAL },
+    { .how.flags = O_PATH | O_NOCTTY, .err = EINVAL },
+    { .how.flags = O_PATH | O_DIRECT, .err = EINVAL },
+
+    /* ->mode must only be set with O_{CREAT,TMPFILE}. */
+    { .how.flags = O_RDONLY, .how.mode = 0600, .err = EINVAL },
+    { .how.flags = O_PATH,   .how.mode = 0600, .err = EINVAL },
+    { .how.flags = O_CREAT,  .how.mode = 0600 },
+    { .how.flags = O_TMPFILE | O_RDWR, .how.mode = 0600 },
+    /* ->mode must only contain 0777 bits. */
+    { .how.flags = O_CREAT, .how.mode = 0xFFFF, .err = EINVAL },
+    { .how.flags = O_CREAT, .how.mode = 0xC000000000000000ULL, .err = EINVAL },
+    { .how.flags = O_TMPFILE | O_RDWR, .how.mode = 0x1337, .err = EINVAL },
+    { .how.flags = O_TMPFILE | O_RDWR, .how.mode = 0x0000A00000000000ULL,
+      .err = EINVAL },
+
+    /* ->resolve flags must not conflict. */
+    { .how.flags = O_RDONLY,
+      .how.resolve = RESOLVE_BENEATH | RESOLVE_IN_ROOT,
+      .err = EINVAL },
+
+    /* ->resolve must only contain RESOLVE_* flags.  */
+    { .how.flags = O_RDONLY,
+      .how.resolve = 0x1337, .err = EINVAL },
+    { .how.flags = O_CREAT,
+      .how.resolve = 0x1337, .err = EINVAL },
+    { .how.flags = O_TMPFILE | O_RDWR,
+      .how.resolve = 0x1337, .err = EINVAL },
+    { .how.flags = O_PATH,
+      .how.resolve = 0x1337, .err = EINVAL },
+
+    /* currently unknown upper 32 bit rejected.  */
+    { .how.flags = O_RDONLY | (1ULL << 63),
+      .how.resolve = 0, .err = EINVAL },
+  };
+
+  for (struct flag_test *t = tests; t != array_end (tests); t++)
+    {
+      char *path;
+      if (t->how.flags & O_CREAT)
+	{
+	  int temp_fd = create_temp_file ("tst-openat2.", &path);
+	  TEST_VERIFY_EXIT (temp_fd != -1);
+	  xunlink (path);
+	}
+      else
+	path = (char *) ".";
+
+      int fd = openat2 (AT_FDCWD, path, &t->how, sizeof (struct open_how));
+      if (fd != 0 && errno == EOPNOTSUPP)
+	{
+	  /* Skip the testcase if FS does not support the operation (e.g.
+	     valid O_TMPFILE on NFS).  */
+	  continue;
+	}
+
+      if (t->err != 0)
+	{
+	  TEST_COMPARE (fd, -1);
+	  TEST_COMPARE (errno, t->err);
+	}
+      else
+	TEST_VERIFY (fd >= 0);
+    }
+
+  return 0;
+}
+
+static int
+do_test_basic (void)
+{
+  int fd;
+
+  fd = openat2 (dir_fd,
+		"some-file",
+		&(struct open_how)
+		{
+		  .flags = O_CREAT|O_RDWR|O_EXCL,
+		  .mode = 0666,
+		},
+		sizeof (struct open_how));
+  TEST_VERIFY (fd != -1);
+
+  xwrite (fd, "hello", 5);
+
+  /* Before closing the file, try using this file descriptor to open
+     another file.  This must fail.  */
+  {
+    int fd2 = openat2 (fd,
+		       "should-not-work",
+		       &(struct open_how)
+		       {
+			 .flags = O_CREAT|O_RDWR|O_EXCL,
+			 .mode = 0666,
+		       },
+		       sizeof (struct open_how));
+    TEST_COMPARE (fd2, -1);
+    TEST_COMPARE (errno, ENOTDIR);
+  }
+
+  /* Remove the created file.  */
+  int cwdfd = xopen (".", O_RDONLY | O_DIRECTORY, 0);
+  TEST_COMPARE (fchdir (dir_fd), 0);
+  xunlink ("some-file");
+  TEST_COMPARE (fchdir (cwdfd), 0);
+
+  xclose (dir_fd);
+  xclose (cwdfd);
+
+  fd = openat2 (dir_fd,
+		"some-file",
+		&(struct open_how)
+		{
+		  .flags = O_CREAT|O_RDWR|O_EXCL,
+		  .mode = 0666,
+		},
+		sizeof (struct open_how));
+  TEST_COMPARE (fd, -1);
+  TEST_COMPARE (errno, EBADF);
+
+  return 0;
+}
+
+static int
+do_test (void)
+{
+  do_test_struct ();
+  do_test_flags ();
+  do_test_basic ();
+
+  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 aea7848ed6..a7f177c8a8 100644
--- a/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
@@ -2744,6 +2744,7 @@ GLIBC_2.4 sys_errlist D 0x420
 GLIBC_2.4 sys_nerr D 0x4
 GLIBC_2.4 unlinkat F
 GLIBC_2.4 unshare F
+GLIBC_2.40 openat2 F
 GLIBC_2.5 __readlinkat_chk F
 GLIBC_2.5 inet6_opt_append F
 GLIBC_2.5 inet6_opt_find F
diff --git a/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist b/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
index 4ab3681914..00dfc8f1e7 100644
--- a/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
@@ -2763,3 +2763,4 @@ GLIBC_2.39 stdc_trailing_zeros_ui F
 GLIBC_2.39 stdc_trailing_zeros_ul F
 GLIBC_2.39 stdc_trailing_zeros_ull F
 GLIBC_2.39 stdc_trailing_zeros_us F
+GLIBC_2.40 openat2 F