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[PATCH] Implement the mlock2 function
- From: fweimer at redhat dot com (Florian Weimer)
- To: libc-alpha at sourceware dot org
- Date: Fri, 24 Nov 2017 17:59:36 +0100
- Subject: [PATCH] Implement the mlock2 function
- Authentication-results: sourceware.org; auth=none
Fallback using mlock is provided if the flags argument is zero.
2017-11-24 Florian Weimer <fweimer@redhat.com>
* sysdeps/unix/sysv/linux/mlock2.c: New file.
* sysdeps/unix/sysv/linux/tst-mlock2.c: Likewise.
* sysdeps/unix/sysv/linux/Makefile (routines): Add mlock2.
(tests): Add tst-mlock2.
* sysdeps/unix/sysv/linux/Versions (GLIBC_2.27): Export mlock2.
* sysdeps/unix/sysv/linux/libc**.abilist: Update.
* manual/memory.texi (Page Lock Functions): Move @end deftypefun
for mlock. Document mlock2.
diff --git a/manual/memory.texi b/manual/memory.texi
index 3f5dd90260..1b431bf5da 100644
--- a/manual/memory.texi
+++ b/manual/memory.texi
@@ -3337,6 +3337,36 @@ The calling process is not superuser.
The kernel does not provide @code{mlock} capability.
@end table
+@end deftypefun
+
+@deftypefun int mlock2 (const void *@var{addr}, size_t @var{len}, unsigned int @var{flags})
+@standards{Linux, sys/mman.h}
+@safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}}
+
+This function is similar to @code{mlock}. If @var{flags} is zero, a
+call to @code{mlock2} behaves exactly as the equivalent call to @code{mlock}.
+
+The @var{flags} argument must be a combination of zero or more of the
+following flags:
+
+@vtable @code
+@item MLOCK_ONFAULT
+@standards{Linux, sys/mman.h}
+Only those pages in the specified address range which are already in
+memory are locked immediately. Additional pages in the range are
+automatically locked in case of a page fault and allocation of memory.
+@end vtable
+
+Like @code{mlock}, @code{mlock2} returns zero on success and @code{-1}
+on failure, setting @code{errno} accordingly. Additional @code{errno}
+values defined for @code{mlock2} are:
+
+@table @code
+@item EINVAL
+The specified (non-zero) @var{flags} argument is not supported by this
+system.
+@end table
+@end deftypefun
You can lock @emph{all} a process' memory with @code{mlockall}. You
unlock memory with @code{munlock} or @code{munlockall}.
@@ -3346,8 +3376,6 @@ To avoid all page faults in a C program, you have to use
from the C code, e.g. the stack and automatic variables, and you
wouldn't know what address to tell @code{mlock}.
-@end deftypefun
-
@deftypefun int munlock (const void *@var{addr}, size_t @var{len})
@standards{POSIX.1b, sys/mman.h}
@safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}}
diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile
index 58ce07b526..478f7e3d4d 100644
--- a/sysdeps/unix/sysv/linux/Makefile
+++ b/sysdeps/unix/sysv/linux/Makefile
@@ -18,7 +18,7 @@ sysdep_routines += clone umount umount2 readahead \
setfsuid setfsgid epoll_pwait signalfd \
eventfd eventfd_read eventfd_write prlimit \
personality epoll_wait tee vmsplice splice \
- open_by_handle_at
+ open_by_handle_at mlock2
CFLAGS-gethostid.c = -fexceptions
CFLAGS-tee.c = -fexceptions -fasynchronous-unwind-tables
@@ -44,7 +44,7 @@ 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
+ test-errno-linux tst-memfd_create tst-mlock2
# 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/Versions b/sysdeps/unix/sysv/linux/Versions
index 6f2fe516d7..e799b62285 100644
--- a/sysdeps/unix/sysv/linux/Versions
+++ b/sysdeps/unix/sysv/linux/Versions
@@ -168,6 +168,7 @@ libc {
}
GLIBC_2.27 {
memfd_create;
+ mlock2;
}
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 140ca28abc..f81fd9d31b 100644
--- a/sysdeps/unix/sysv/linux/aarch64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/aarch64/libc.abilist
@@ -2107,6 +2107,7 @@ GLIBC_2.27 GLIBC_2.27 A
GLIBC_2.27 glob F
GLIBC_2.27 glob64 F
GLIBC_2.27 memfd_create F
+GLIBC_2.27 mlock2 F
GLIBC_2.27 strfromf128 F
GLIBC_2.27 strtof128 F
GLIBC_2.27 strtof128_l F
diff --git a/sysdeps/unix/sysv/linux/alpha/libc.abilist b/sysdeps/unix/sysv/linux/alpha/libc.abilist
index f698e1b2f4..9e7867b618 100644
--- a/sysdeps/unix/sysv/linux/alpha/libc.abilist
+++ b/sysdeps/unix/sysv/linux/alpha/libc.abilist
@@ -2018,6 +2018,7 @@ GLIBC_2.27 GLIBC_2.27 A
GLIBC_2.27 glob F
GLIBC_2.27 glob64 F
GLIBC_2.27 memfd_create F
+GLIBC_2.27 mlock2 F
GLIBC_2.27 strfromf128 F
GLIBC_2.27 strtof128 F
GLIBC_2.27 strtof128_l F
diff --git a/sysdeps/unix/sysv/linux/arm/libc.abilist b/sysdeps/unix/sysv/linux/arm/libc.abilist
index 8a8af3e3e4..a5ce7964d0 100644
--- a/sysdeps/unix/sysv/linux/arm/libc.abilist
+++ b/sysdeps/unix/sysv/linux/arm/libc.abilist
@@ -108,6 +108,7 @@ GLIBC_2.27 GLIBC_2.27 A
GLIBC_2.27 glob F
GLIBC_2.27 glob64 F
GLIBC_2.27 memfd_create F
+GLIBC_2.27 mlock2 F
GLIBC_2.4 GLIBC_2.4 A
GLIBC_2.4 _Exit F
GLIBC_2.4 _IO_2_1_stderr_ D 0xa0
diff --git a/sysdeps/unix/sysv/linux/bits/mman-shared.h b/sysdeps/unix/sysv/linux/bits/mman-shared.h
index 5bbcbbc14a..bee99c2384 100644
--- a/sysdeps/unix/sysv/linux/bits/mman-shared.h
+++ b/sysdeps/unix/sysv/linux/bits/mman-shared.h
@@ -28,12 +28,21 @@
# define MFD_HUGETLB 4U
# endif
+/* Flags for mlock2. */
+# ifndef MLOCK_ONFAULT
+# define MLOCK_ONFAULT 1U
+# endif
+
__BEGIN_DECLS
/* Create a new memory file descriptor. NAME is a name for debugging.
FLAGS is a combination of the MFD_* constants. */
int memfd_create (const char *__name, unsigned int __flags) __THROW;
+/* Lock pages from ADDR (inclusive) to ADDR + LENGTH (exclusive) into
+ memory. FLAGS is a combination of the MLOCK_* flags above. */
+int mlock2 (const void *__addr, size_t __length, unsigned int __flags) __THROW;
+
__END_DECLS
#endif /* __USE_GNU */
diff --git a/sysdeps/unix/sysv/linux/hppa/libc.abilist b/sysdeps/unix/sysv/linux/hppa/libc.abilist
index 5b81a6cd7d..69ddf15361 100644
--- a/sysdeps/unix/sysv/linux/hppa/libc.abilist
+++ b/sysdeps/unix/sysv/linux/hppa/libc.abilist
@@ -1872,6 +1872,7 @@ GLIBC_2.27 GLIBC_2.27 A
GLIBC_2.27 glob F
GLIBC_2.27 glob64 F
GLIBC_2.27 memfd_create F
+GLIBC_2.27 mlock2 F
GLIBC_2.3 GLIBC_2.3 A
GLIBC_2.3 __ctype_b_loc F
GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/i386/libc.abilist b/sysdeps/unix/sysv/linux/i386/libc.abilist
index 51ead9e867..b835c55847 100644
--- a/sysdeps/unix/sysv/linux/i386/libc.abilist
+++ b/sysdeps/unix/sysv/linux/i386/libc.abilist
@@ -2037,6 +2037,7 @@ GLIBC_2.27 GLIBC_2.27 A
GLIBC_2.27 glob F
GLIBC_2.27 glob64 F
GLIBC_2.27 memfd_create F
+GLIBC_2.27 mlock2 F
GLIBC_2.3 GLIBC_2.3 A
GLIBC_2.3 __ctype_b_loc F
GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/ia64/libc.abilist b/sysdeps/unix/sysv/linux/ia64/libc.abilist
index 78b4ee8d40..5e6932b725 100644
--- a/sysdeps/unix/sysv/linux/ia64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/ia64/libc.abilist
@@ -1901,6 +1901,7 @@ GLIBC_2.27 GLIBC_2.27 A
GLIBC_2.27 glob F
GLIBC_2.27 glob64 F
GLIBC_2.27 memfd_create F
+GLIBC_2.27 mlock2 F
GLIBC_2.3 GLIBC_2.3 A
GLIBC_2.3 __ctype_b_loc F
GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/kernel-features.h b/sysdeps/unix/sysv/linux/kernel-features.h
index 2e1fe6597a..59b613377f 100644
--- a/sysdeps/unix/sysv/linux/kernel-features.h
+++ b/sysdeps/unix/sysv/linux/kernel-features.h
@@ -107,3 +107,7 @@
#if __LINUX_KERNEL_VERSION >= 0x031300
# define __ASSUME_EXECVEAT 1
#endif
+
+#if __LINUX_KERNEL_VERSION >= 0x040400
+# define __ASSUME_MLOCK2 1
+#endif
diff --git a/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist b/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
index d9c97779e4..01d10d907c 100644
--- a/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
+++ b/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
@@ -109,6 +109,7 @@ GLIBC_2.27 GLIBC_2.27 A
GLIBC_2.27 glob F
GLIBC_2.27 glob64 F
GLIBC_2.27 memfd_create F
+GLIBC_2.27 mlock2 F
GLIBC_2.4 GLIBC_2.4 A
GLIBC_2.4 _Exit F
GLIBC_2.4 _IO_2_1_stderr_ D 0x98
diff --git a/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist b/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
index 4acbf7eeed..3ad08c20bf 100644
--- a/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
+++ b/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
@@ -1986,6 +1986,7 @@ GLIBC_2.27 GLIBC_2.27 A
GLIBC_2.27 glob F
GLIBC_2.27 glob64 F
GLIBC_2.27 memfd_create F
+GLIBC_2.27 mlock2 F
GLIBC_2.3 GLIBC_2.3 A
GLIBC_2.3 __ctype_b_loc F
GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/microblaze/libc.abilist b/sysdeps/unix/sysv/linux/microblaze/libc.abilist
index 93f02f08ce..6bd7be1929 100644
--- a/sysdeps/unix/sysv/linux/microblaze/libc.abilist
+++ b/sysdeps/unix/sysv/linux/microblaze/libc.abilist
@@ -2107,3 +2107,4 @@ GLIBC_2.27 GLIBC_2.27 A
GLIBC_2.27 glob F
GLIBC_2.27 glob64 F
GLIBC_2.27 memfd_create F
+GLIBC_2.27 mlock2 F
diff --git a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
index 795e85de70..9b1e890eda 100644
--- a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
@@ -1961,6 +1961,7 @@ GLIBC_2.27 GLIBC_2.27 A
GLIBC_2.27 glob F
GLIBC_2.27 glob64 F
GLIBC_2.27 memfd_create F
+GLIBC_2.27 mlock2 F
GLIBC_2.3 GLIBC_2.3 A
GLIBC_2.3 __ctype_b_loc F
GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
index dc714057b7..3eb5b66f8b 100644
--- a/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
@@ -1959,6 +1959,7 @@ GLIBC_2.27 GLIBC_2.27 A
GLIBC_2.27 glob F
GLIBC_2.27 glob64 F
GLIBC_2.27 memfd_create F
+GLIBC_2.27 mlock2 F
GLIBC_2.3 GLIBC_2.3 A
GLIBC_2.3 __ctype_b_loc F
GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
index ce7bc9b175..d371658dc6 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
@@ -1957,6 +1957,7 @@ GLIBC_2.27 GLIBC_2.27 A
GLIBC_2.27 glob F
GLIBC_2.27 glob64 F
GLIBC_2.27 memfd_create F
+GLIBC_2.27 mlock2 F
GLIBC_2.27 strfromf128 F
GLIBC_2.27 strtof128 F
GLIBC_2.27 strtof128_l F
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
index 3fdd85eace..cbb0849fb9 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
@@ -1952,6 +1952,7 @@ GLIBC_2.27 GLIBC_2.27 A
GLIBC_2.27 glob F
GLIBC_2.27 glob64 F
GLIBC_2.27 memfd_create F
+GLIBC_2.27 mlock2 F
GLIBC_2.27 strfromf128 F
GLIBC_2.27 strtof128 F
GLIBC_2.27 strtof128_l F
diff --git a/sysdeps/unix/sysv/linux/mlock2.c b/sysdeps/unix/sysv/linux/mlock2.c
new file mode 100644
index 0000000000..1646cfb9e1
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/mlock2.c
@@ -0,0 +1,40 @@
+/* Wrapper for the mlock2 system call with fallback to mlock.
+ Copyright (C) 2017 Free Software Foundation, Inc.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+#include <sys/mman.h>
+#include <errno.h>
+#include <sysdep.h>
+
+int
+mlock2 (const void *addr, size_t length, unsigned int flags)
+{
+#ifdef __ASSUME_MLOCK2
+ return INLINE_SYSCALL (mlock2, 3, addr, length, flags);
+#else
+ if (flags == 0)
+ return INLINE_SYSCALL (mlock, 2, addr, length);
+# ifdef __NR_mlock2
+ int ret = INLINE_SYSCALL (mlock2, 3, addr, length, flags);
+ if (ret == 0 || errno != ENOSYS)
+ return ret;
+# endif /* __NR_mlock2 */
+ /* Treat the missing system call as an invalid (non-zero) flag
+ argument. */
+ __set_errno (EINVAL);
+ return -1;
+#endif /* __ASSUME_MLOCK2 */
+}
diff --git a/sysdeps/unix/sysv/linux/nios2/libc.abilist b/sysdeps/unix/sysv/linux/nios2/libc.abilist
index 3e0bcb2a5c..afacf1ff2d 100644
--- a/sysdeps/unix/sysv/linux/nios2/libc.abilist
+++ b/sysdeps/unix/sysv/linux/nios2/libc.abilist
@@ -2148,3 +2148,4 @@ GLIBC_2.27 GLIBC_2.27 A
GLIBC_2.27 glob F
GLIBC_2.27 glob64 F
GLIBC_2.27 memfd_create F
+GLIBC_2.27 mlock2 F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
index 375c69d9d1..48af097b6a 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
@@ -1990,6 +1990,7 @@ GLIBC_2.27 GLIBC_2.27 A
GLIBC_2.27 glob F
GLIBC_2.27 glob64 F
GLIBC_2.27 memfd_create F
+GLIBC_2.27 mlock2 F
GLIBC_2.3 GLIBC_2.3 A
GLIBC_2.3 __ctype_b_loc F
GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
index a88172a906..e30535dac9 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
@@ -1995,6 +1995,7 @@ GLIBC_2.27 GLIBC_2.27 A
GLIBC_2.27 glob F
GLIBC_2.27 glob64 F
GLIBC_2.27 memfd_create F
+GLIBC_2.27 mlock2 F
GLIBC_2.3 GLIBC_2.3 A
GLIBC_2.3 __ctype_b_loc F
GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist
index fa026a332c..f73f193523 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist
@@ -2202,3 +2202,4 @@ GLIBC_2.27 GLIBC_2.27 A
GLIBC_2.27 glob F
GLIBC_2.27 glob64 F
GLIBC_2.27 memfd_create F
+GLIBC_2.27 mlock2 F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist
index 838f395d78..d3092afd25 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist
@@ -109,6 +109,7 @@ GLIBC_2.27 GLIBC_2.27 A
GLIBC_2.27 glob F
GLIBC_2.27 glob64 F
GLIBC_2.27 memfd_create F
+GLIBC_2.27 mlock2 F
GLIBC_2.3 GLIBC_2.3 A
GLIBC_2.3 _Exit F
GLIBC_2.3 _IO_2_1_stderr_ D 0xe0
diff --git a/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist b/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
index 41b79c496a..81fdcba9cf 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
@@ -1990,6 +1990,7 @@ GLIBC_2.27 GLIBC_2.27 A
GLIBC_2.27 glob F
GLIBC_2.27 glob64 F
GLIBC_2.27 memfd_create F
+GLIBC_2.27 mlock2 F
GLIBC_2.27 strfromf128 F
GLIBC_2.27 strtof128 F
GLIBC_2.27 strtof128_l F
diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist b/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
index 68251a0e69..84a46022f6 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
@@ -1891,6 +1891,7 @@ GLIBC_2.27 GLIBC_2.27 A
GLIBC_2.27 glob F
GLIBC_2.27 glob64 F
GLIBC_2.27 memfd_create F
+GLIBC_2.27 mlock2 F
GLIBC_2.27 strfromf128 F
GLIBC_2.27 strtof128 F
GLIBC_2.27 strtof128_l F
diff --git a/sysdeps/unix/sysv/linux/sh/libc.abilist b/sysdeps/unix/sysv/linux/sh/libc.abilist
index bc1aae275e..1ee21fe8e8 100644
--- a/sysdeps/unix/sysv/linux/sh/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sh/libc.abilist
@@ -1876,6 +1876,7 @@ GLIBC_2.27 GLIBC_2.27 A
GLIBC_2.27 glob F
GLIBC_2.27 glob64 F
GLIBC_2.27 memfd_create F
+GLIBC_2.27 mlock2 F
GLIBC_2.3 GLIBC_2.3 A
GLIBC_2.3 __ctype_b_loc F
GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist b/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
index 93e6d092ac..3c96754414 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
@@ -1983,6 +1983,7 @@ GLIBC_2.27 GLIBC_2.27 A
GLIBC_2.27 glob F
GLIBC_2.27 glob64 F
GLIBC_2.27 memfd_create F
+GLIBC_2.27 mlock2 F
GLIBC_2.27 strfromf128 F
GLIBC_2.27 strtof128 F
GLIBC_2.27 strtof128_l F
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist b/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
index b11d6764d4..51a09f0c4e 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
@@ -1920,6 +1920,7 @@ GLIBC_2.27 GLIBC_2.27 A
GLIBC_2.27 glob F
GLIBC_2.27 glob64 F
GLIBC_2.27 memfd_create F
+GLIBC_2.27 mlock2 F
GLIBC_2.27 strfromf128 F
GLIBC_2.27 strtof128 F
GLIBC_2.27 strtof128_l F
diff --git a/sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist b/sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist
index e9eb4ff7bd..57427eb3ee 100644
--- a/sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist
@@ -2114,3 +2114,4 @@ GLIBC_2.27 GLIBC_2.27 A
GLIBC_2.27 glob F
GLIBC_2.27 glob64 F
GLIBC_2.27 memfd_create F
+GLIBC_2.27 mlock2 F
diff --git a/sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist b/sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist
index 8f08e909cd..321f65c600 100644
--- a/sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist
@@ -2114,3 +2114,4 @@ GLIBC_2.27 GLIBC_2.27 A
GLIBC_2.27 glob F
GLIBC_2.27 glob64 F
GLIBC_2.27 memfd_create F
+GLIBC_2.27 mlock2 F
diff --git a/sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist b/sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist
index e9eb4ff7bd..57427eb3ee 100644
--- a/sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist
+++ b/sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist
@@ -2114,3 +2114,4 @@ GLIBC_2.27 GLIBC_2.27 A
GLIBC_2.27 glob F
GLIBC_2.27 glob64 F
GLIBC_2.27 memfd_create F
+GLIBC_2.27 mlock2 F
diff --git a/sysdeps/unix/sysv/linux/tst-mlock2.c b/sysdeps/unix/sysv/linux/tst-mlock2.c
new file mode 100644
index 0000000000..53c435a12a
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/tst-mlock2.c
@@ -0,0 +1,66 @@
+/* Test the mlock2 function.
+ Copyright (C) 2017 Free Software Foundation, Inc.
+
+ 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 <support/xunistd.h>
+#include <sys/mman.h>
+
+/* Allocate a page using mmap. */
+static void *
+get_page (void)
+{
+ return xmmap (NULL, 1, PROT_READ | PROT_WRITE,
+ MAP_ANONYMOUS | MAP_PRIVATE, -1);
+}
+
+static int
+do_test (void)
+{
+ /* Current kernels have a small reserve of locked memory, so this
+ test does not need any privileges to run. */
+
+ void *page = get_page ();
+ if (mlock (page, 1) != 0)
+ FAIL_EXIT1 ("mlock: %m\n");
+ xmunmap (page, 1);
+
+ page = get_page ();
+ if (mlock2 (page, 1, 0) != 0)
+ /* Should be implemented using mlock if necessary. */
+ FAIL_EXIT1 ("mlock2 (0): %m\n");
+ xmunmap (page, 1);
+
+ page = get_page ();
+ int ret = mlock2 (page, 1, MLOCK_ONFAULT);
+ if (ret != 0)
+ {
+ TEST_VERIFY (ret == -1);
+ if (errno != EINVAL)
+ /* EINVAL means the system does not support the mlock2 system
+ call. */
+ FAIL_EXIT1 ("mlock2 (0): %m\n");
+ else
+ puts ("warning: mlock2 system call not supported");
+ }
+ xmunmap (page, 1);
+
+ 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 0a4f7797ac..6b2e72d64e 100644
--- a/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
@@ -1878,6 +1878,7 @@ GLIBC_2.27 GLIBC_2.27 A
GLIBC_2.27 glob F
GLIBC_2.27 glob64 F
GLIBC_2.27 memfd_create F
+GLIBC_2.27 mlock2 F
GLIBC_2.3 GLIBC_2.3 A
GLIBC_2.3 __ctype_b_loc F
GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist b/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
index 23f6a91429..1d8e0286e3 100644
--- a/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
@@ -2121,3 +2121,4 @@ GLIBC_2.27 GLIBC_2.27 A
GLIBC_2.27 glob F
GLIBC_2.27 glob64 F
GLIBC_2.27 memfd_create F
+GLIBC_2.27 mlock2 F