diff mbox

Linux: Implement membarrier function

Message ID 87k1k859km.fsf@oldenburg2.str.redhat.com
State New, archived
Headers show

Commit Message

Florian Weimer Dec. 17, 2018, 5:47 p.m. UTC
* Adhemerval Zanella:

>> Well, that already happens with the duplicated header approach if users
>> want to use UAPI headers, too.  It requires complicated synchronization
>> to make it work.
>
> But at least glibc is not imposing it, if user want to use kernel uapi
> header he will explicit include it and it is up to kernel provide a sane
> implementation.

This only works if the header does not include system call wrapper.

>> We can tweak the conditional for the header inclusion further, like
>> this:
>> 
>> +#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 16, 0) \
>> +  || __glibc_has_include (<linux/membarrier.h>) \
>> +# include <linux/membarrier.h>
>> +#else
>> 
>> With GCC 5 and later, this would always prefer the kernel header if
>> available.  There would never be a conflict between the definitions,
>> irrespective of header file inclusion order.
>> 
>> What do you think?
>
> In any case I don't think my suggestion should be a blocker, we
> already rely on linux header for some cases and it seems I am alone in
> trying to decouple glibc from kernel headers.

Okay.  I've reconsidered the header baseline approach and I'm now
proposing to go with the 4.3 header version, the first which had the
system call.  With a later baseline, you'd get an error if you include
<linux/membarrier.h> before <sys/membarrier.h> and the kernel is older
than the chosen baseline.  This cannot happen if we pick the first
supported kernel version as the baseline.  (This will not matter if we
eventually choose the use the __has_include trick and the compiler
supports __has_include.)

I had to adjust the test to define a private copy of the subsequently
added constants.

Thanks,
Florian

2018-12-17  Florian Weimer  <fweimer@redhat.com>

	Linux: Implement membarrier function.
	* sysdeps/unix/sysv/linux/Makefile (sysdep_headers): Add
	sys/membarrier.h.
	(tests): Add tst-membarrier.
	* sysdeps/unix/sysv/linux/Versions (GLIBC_2.27): Add membarrier.
	* sysdeps/unix/sysv/linux/sys/membarrier.h: New file.
	* sysdeps/unix/sysv/linux/tst-membarrier.c: Likewise.
	* sysdeps/unix/sysv/linux/aarch64/libc.abilist (GLIBC_2.29): Add
	membarrier.
	* sysdeps/unix/sysv/linux/alpha/libc.abilist (GLIBC_2.29):
	Likewise.
	* sysdeps/unix/sysv/linux/arm/libc.abilist (GLIBC_2.29): Likewise.
	* sysdeps/unix/sysv/linux/hppa/libc.abilist (GLIBC_2.29):
	Likewise.
	* sysdeps/unix/sysv/linux/i386/libc.abilist (GLIBC_2.29):
	Likewise.
	* sysdeps/unix/sysv/linux/ia64/libc.abilist (GLIBC_2.29):
	Likewise.
	* sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist (GLIBC_2.29):
	Likewise.
	* sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist (GLIBC_2.29):
	Likewise.
	* sysdeps/unix/sysv/linux/microblaze/libc.abilist (GLIBC_2.29):
	Likewise.
	* sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
	(GLIBC_2.29): Likewise.
	* sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
	(GLIBC_2.29): Likewise.
	* sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
	(GLIBC_2.29): Likewise.
	* sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
	(GLIBC_2.29): Likewise.
	* sysdeps/unix/sysv/linux/nios2/libc.abilist (GLIBC_2.29):
	Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
	(GLIBC_2.29): Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
	(GLIBC_2.29): Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist
	(GLIBC_2.29): Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist
	(GLIBC_2.29): Likewise.
	* sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist (GLIBC_2.29):
	Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist (GLIBC_2.29):
	Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist (GLIBC_2.29):
	Likewise.
	* sysdeps/unix/sysv/linux/sh/libc.abilist (GLIBC_2.29): Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist (GLIBC_2.29):
	Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist (GLIBC_2.29):
	Likewise.
	* sysdeps/unix/sysv/linux/x86_64/64/libc.abilist (GLIBC_2.29):
	Likewise.
	* sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist (GLIBC_2.29):
	Likewise.
diff mbox

Patch

diff --git a/NEWS b/NEWS
index ae80818df4..d8cefe90dd 100644
--- a/NEWS
+++ b/NEWS
@@ -46,6 +46,9 @@  Major new features:
   incosistent mutex state after fork call in multithread environment.
   In both popen and system there is no direct access to user-defined mutexes.
 
+* On Linux, The membarrier function and the <sys/membarrier.h> header file
+  have been added.
+
 Deprecated and removed features, and other changes affecting compatibility:
 
 * The glibc.tune tunable namespace has been renamed to glibc.cpu and the
diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile
index 2c1a7dd274..74138429d6 100644
--- a/sysdeps/unix/sysv/linux/Makefile
+++ b/sysdeps/unix/sysv/linux/Makefile
@@ -43,12 +43,13 @@  sysdep_headers += sys/mount.h sys/acct.h sys/sysctl.h \
 		  bits/siginfo-arch.h bits/siginfo-consts-arch.h \
 		  bits/procfs.h bits/procfs-id.h bits/procfs-extra.h \
 		  bits/procfs-prregset.h bits/mman-map-flags-generic.h \
-		  bits/msq-pad.h bits/sem-pad.h bits/shmlba.h bits/shm-pad.h
+		  bits/msq-pad.h bits/sem-pad.h bits/shmlba.h bits/shm-pad.h \
+		  sys/membarrier.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-ofdlocks
+	 tst-rlimit-infinity tst-ofdlocks tst-membarrier
 tests-internal += tst-ofdlocks-compat
 
 
diff --git a/sysdeps/unix/sysv/linux/Versions b/sysdeps/unix/sysv/linux/Versions
index f1e12d9c69..39a61b29eb 100644
--- a/sysdeps/unix/sysv/linux/Versions
+++ b/sysdeps/unix/sysv/linux/Versions
@@ -173,6 +173,7 @@  libc {
   }
   GLIBC_2.29 {
     getcpu;
+    membarrier;
   }
   GLIBC_PRIVATE {
     # functions used in other libraries
diff --git a/sysdeps/unix/sysv/linux/aarch64/libc.abilist b/sysdeps/unix/sysv/linux/aarch64/libc.abilist
index 9c330f325e..eff4b1d055 100644
--- a/sysdeps/unix/sysv/linux/aarch64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/aarch64/libc.abilist
@@ -2139,5 +2139,6 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 getcpu F
+GLIBC_2.29 membarrier F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
 GLIBC_2.29 posix_spawn_file_actions_addfchdir_np F
diff --git a/sysdeps/unix/sysv/linux/alpha/libc.abilist b/sysdeps/unix/sysv/linux/alpha/libc.abilist
index f630fa4c6f..6f37593acc 100644
--- a/sysdeps/unix/sysv/linux/alpha/libc.abilist
+++ b/sysdeps/unix/sysv/linux/alpha/libc.abilist
@@ -2034,6 +2034,7 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 getcpu F
+GLIBC_2.29 membarrier F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
 GLIBC_2.29 posix_spawn_file_actions_addfchdir_np F
 GLIBC_2.3 __ctype_b_loc F
diff --git a/sysdeps/unix/sysv/linux/arm/libc.abilist b/sysdeps/unix/sysv/linux/arm/libc.abilist
index b96f45590f..b2e5cc4113 100644
--- a/sysdeps/unix/sysv/linux/arm/libc.abilist
+++ b/sysdeps/unix/sysv/linux/arm/libc.abilist
@@ -124,6 +124,7 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 getcpu F
+GLIBC_2.29 membarrier F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
 GLIBC_2.29 posix_spawn_file_actions_addfchdir_np F
 GLIBC_2.4 _Exit F
diff --git a/sysdeps/unix/sysv/linux/hppa/libc.abilist b/sysdeps/unix/sysv/linux/hppa/libc.abilist
index 088a8ee369..a45c266c33 100644
--- a/sysdeps/unix/sysv/linux/hppa/libc.abilist
+++ b/sysdeps/unix/sysv/linux/hppa/libc.abilist
@@ -1881,6 +1881,7 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 getcpu F
+GLIBC_2.29 membarrier F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
 GLIBC_2.29 posix_spawn_file_actions_addfchdir_np F
 GLIBC_2.3 __ctype_b_loc F
diff --git a/sysdeps/unix/sysv/linux/i386/libc.abilist b/sysdeps/unix/sysv/linux/i386/libc.abilist
index f7ff2c57b9..3597737fb2 100644
--- a/sysdeps/unix/sysv/linux/i386/libc.abilist
+++ b/sysdeps/unix/sysv/linux/i386/libc.abilist
@@ -2046,6 +2046,7 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 getcpu F
+GLIBC_2.29 membarrier F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
 GLIBC_2.29 posix_spawn_file_actions_addfchdir_np F
 GLIBC_2.3 __ctype_b_loc F
diff --git a/sysdeps/unix/sysv/linux/ia64/libc.abilist b/sysdeps/unix/sysv/linux/ia64/libc.abilist
index becd8b1033..908e8b4d52 100644
--- a/sysdeps/unix/sysv/linux/ia64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/ia64/libc.abilist
@@ -1915,6 +1915,7 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 getcpu F
+GLIBC_2.29 membarrier F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
 GLIBC_2.29 posix_spawn_file_actions_addfchdir_np F
 GLIBC_2.3 __ctype_b_loc F
diff --git a/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist b/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
index 74e42a5209..8fc66fd450 100644
--- a/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
+++ b/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
@@ -125,6 +125,7 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 getcpu F
+GLIBC_2.29 membarrier F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
 GLIBC_2.29 posix_spawn_file_actions_addfchdir_np F
 GLIBC_2.4 _Exit F
diff --git a/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist b/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
index 4af5a74e8a..e4c60d6f83 100644
--- a/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
+++ b/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
@@ -1990,6 +1990,7 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 getcpu F
+GLIBC_2.29 membarrier F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
 GLIBC_2.29 posix_spawn_file_actions_addfchdir_np F
 GLIBC_2.3 __ctype_b_loc F
diff --git a/sysdeps/unix/sysv/linux/microblaze/libc.abilist b/sysdeps/unix/sysv/linux/microblaze/libc.abilist
index ccef673fd2..377e5d7049 100644
--- a/sysdeps/unix/sysv/linux/microblaze/libc.abilist
+++ b/sysdeps/unix/sysv/linux/microblaze/libc.abilist
@@ -2131,5 +2131,6 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 getcpu F
+GLIBC_2.29 membarrier F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
 GLIBC_2.29 posix_spawn_file_actions_addfchdir_np F
diff --git a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
index 1054bb599e..4f93740486 100644
--- a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
@@ -1968,6 +1968,7 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 getcpu F
+GLIBC_2.29 membarrier F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
 GLIBC_2.29 posix_spawn_file_actions_addfchdir_np F
 GLIBC_2.3 __ctype_b_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 4f5b5ffebf..c8e956a922 100644
--- a/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
@@ -1966,6 +1966,7 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 getcpu F
+GLIBC_2.29 membarrier F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
 GLIBC_2.29 posix_spawn_file_actions_addfchdir_np F
 GLIBC_2.3 __ctype_b_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 943aee58d4..6f69ce6478 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
@@ -1974,6 +1974,7 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 getcpu F
+GLIBC_2.29 membarrier F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
 GLIBC_2.29 posix_spawn_file_actions_addfchdir_np F
 GLIBC_2.3 __ctype_b_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 17a5d17ef9..eaf6fdd1a4 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
@@ -1969,6 +1969,7 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 getcpu F
+GLIBC_2.29 membarrier F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
 GLIBC_2.29 posix_spawn_file_actions_addfchdir_np F
 GLIBC_2.3 __ctype_b_loc F
diff --git a/sysdeps/unix/sysv/linux/nios2/libc.abilist b/sysdeps/unix/sysv/linux/nios2/libc.abilist
index 4d62a540fd..d6becb39db 100644
--- a/sysdeps/unix/sysv/linux/nios2/libc.abilist
+++ b/sysdeps/unix/sysv/linux/nios2/libc.abilist
@@ -2172,5 +2172,6 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 getcpu F
+GLIBC_2.29 membarrier F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
 GLIBC_2.29 posix_spawn_file_actions_addfchdir_np F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
index ecc2d6fa13..2b45a9dedf 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
@@ -1994,6 +1994,7 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 getcpu F
+GLIBC_2.29 membarrier F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
 GLIBC_2.29 posix_spawn_file_actions_addfchdir_np F
 GLIBC_2.3 __ctype_b_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 f5830f9c33..a9cb22ec2e 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
@@ -1998,6 +1998,7 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 getcpu F
+GLIBC_2.29 membarrier F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
 GLIBC_2.29 posix_spawn_file_actions_addfchdir_np F
 GLIBC_2.3 __ctype_b_loc F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist
index 633d8f4792..26216a660b 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist
@@ -124,6 +124,7 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 getcpu F
+GLIBC_2.29 membarrier F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
 GLIBC_2.29 posix_spawn_file_actions_addfchdir_np F
 GLIBC_2.3 _Exit F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist
index 2c712636ef..066985b4a4 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist
@@ -2229,5 +2229,6 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 getcpu F
+GLIBC_2.29 membarrier F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
 GLIBC_2.29 posix_spawn_file_actions_addfchdir_np F
diff --git a/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist b/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
index 195bc8b2cf..6b52ed0eeb 100644
--- a/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
@@ -2101,5 +2101,6 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 getcpu F
+GLIBC_2.29 membarrier F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
 GLIBC_2.29 posix_spawn_file_actions_addfchdir_np F
diff --git a/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist b/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
index 334def033c..80db25db0c 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
@@ -2003,6 +2003,7 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 getcpu F
+GLIBC_2.29 membarrier F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
 GLIBC_2.29 posix_spawn_file_actions_addfchdir_np F
 GLIBC_2.3 __ctype_b_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 536f4c4ced..8fcc88ef9a 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
@@ -1909,6 +1909,7 @@  GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 __fentry__ F
 GLIBC_2.29 getcpu F
+GLIBC_2.29 membarrier F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
 GLIBC_2.29 posix_spawn_file_actions_addfchdir_np F
 GLIBC_2.3 __ctype_b_loc F
diff --git a/sysdeps/unix/sysv/linux/sh/libc.abilist b/sysdeps/unix/sysv/linux/sh/libc.abilist
index 30ae3b6ebb..8a49fa8a4b 100644
--- a/sysdeps/unix/sysv/linux/sh/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sh/libc.abilist
@@ -1885,6 +1885,7 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 getcpu F
+GLIBC_2.29 membarrier F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
 GLIBC_2.29 posix_spawn_file_actions_addfchdir_np F
 GLIBC_2.3 __ctype_b_loc F
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist b/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
index 68b107d080..e17b9e72da 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
@@ -1997,6 +1997,7 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 getcpu F
+GLIBC_2.29 membarrier F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
 GLIBC_2.29 posix_spawn_file_actions_addfchdir_np F
 GLIBC_2.3 __ctype_b_loc F
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist b/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
index e5b6a4da50..34f741d00b 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
@@ -1938,6 +1938,7 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 getcpu F
+GLIBC_2.29 membarrier F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
 GLIBC_2.29 posix_spawn_file_actions_addfchdir_np F
 GLIBC_2.3 __ctype_b_loc F
diff --git a/sysdeps/unix/sysv/linux/sys/membarrier.h b/sysdeps/unix/sysv/linux/sys/membarrier.h
new file mode 100644
index 0000000000..0e0941bc1c
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/sys/membarrier.h
@@ -0,0 +1,48 @@ 
+/* Memory barriers.
+   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/>.  */
+
+#ifndef _SYS_MEMBARRIER_H
+#define _SYS_MEMBARRIER_H 1
+
+#include <features.h>
+
+__BEGIN_DECLS
+
+/* Perform a memory barrier on multiple threads.  */
+int membarrier (int __op, int __flags) __THROW;
+
+__END_DECLS
+
+/* Obtain the definitions of the MEMBARRIER_CMD_* constants.  */
+
+#include <linux/version.h>
+#if LINUX_VERSION_CODE >= KERNEL_VERSION (4, 3, 0)
+# include <linux/membarrier.h>
+#else
+
+/* Definitions from Linux 4.3 follow.  */
+
+enum membarrier_cmd
+{
+  MEMBARRIER_CMD_QUERY = 0,
+  MEMBARRIER_CMD_SHARED = 1
+};
+
+#endif
+
+#endif /* _SYS_MEMBARRIER_H */
diff --git a/sysdeps/unix/sysv/linux/syscalls.list b/sysdeps/unix/sysv/linux/syscalls.list
index e24ea29e35..3deee2bc19 100644
--- a/sysdeps/unix/sysv/linux/syscalls.list
+++ b/sysdeps/unix/sysv/linux/syscalls.list
@@ -112,3 +112,4 @@  process_vm_writev EXTRA	process_vm_writev i:ipipii process_vm_writev
 memfd_create    EXTRA	memfd_create	i:si    memfd_create
 pkey_alloc	EXTRA	pkey_alloc	i:ii	pkey_alloc
 pkey_free	EXTRA	pkey_free	i:i	pkey_free
+membarrier	EXTRA	membarrier	i:ii	membarrier
diff --git a/sysdeps/unix/sysv/linux/tst-membarrier.c b/sysdeps/unix/sysv/linux/tst-membarrier.c
new file mode 100644
index 0000000000..48f4cddf02
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/tst-membarrier.c
@@ -0,0 +1,66 @@ 
+/* Tests for the membarrier function.
+   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 <stdio.h>
+#include <support/check.h>
+#include <sys/membarrier.h>
+
+static int
+do_test (void)
+{
+  int supported = membarrier (MEMBARRIER_CMD_QUERY, 0);
+  if (supported == -1)
+    {
+      if (errno == ENOSYS)
+        FAIL_UNSUPPORTED ("membarrier system call not implemented");
+      else
+        FAIL_EXIT1 ("membarrier: %m");
+    }
+
+  if ((supported & MEMBARRIER_CMD_SHARED) == 0)
+    FAIL_UNSUPPORTED ("shared memory barriers not supported");
+
+  puts ("info: membarrier is supported on this system");
+
+  /* This was not included in the original implementation in Linux
+     4.3.  */
+  const enum membarrier_cmd cmd_private_expedited = 8;
+  const enum membarrier_cmd cmd_register_private_expedited = 16;
+
+  /* The shared barrier is always implemented.  */
+  TEST_COMPARE (supported & MEMBARRIER_CMD_SHARED, MEMBARRIER_CMD_SHARED);
+  TEST_COMPARE (membarrier (MEMBARRIER_CMD_SHARED, 0), 0);
+
+  /* If the private-expedited barrier is advertised, execute it after
+     registering the intent.  */
+  if (supported & cmd_private_expedited)
+    {
+      puts ("info: MEMBARRIER_CMD_PRIVATE_EXPEDITED is supported");
+      TEST_COMPARE (supported & cmd_register_private_expedited,
+                    cmd_register_private_expedited);
+      TEST_COMPARE (membarrier (cmd_register_private_expedited, 0), 0);
+      TEST_COMPARE (membarrier (cmd_private_expedited, 0), 0);
+    }
+  else
+    puts ("info: MEMBARRIER_CMD_PRIVATE_EXPEDITED not supported");
+
+  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 86dfb0c94d..6f15b7b371 100644
--- a/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
@@ -1896,6 +1896,7 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 getcpu F
+GLIBC_2.29 membarrier F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
 GLIBC_2.29 posix_spawn_file_actions_addfchdir_np F
 GLIBC_2.3 __ctype_b_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 dd688263aa..88e1e1f36d 100644
--- a/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
@@ -2147,5 +2147,6 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 getcpu F
+GLIBC_2.29 membarrier F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
 GLIBC_2.29 posix_spawn_file_actions_addfchdir_np F