[v2,08/10] Use clock_gettime to implement gettimeofday.

Message ID 20190828153236.18229-9-zackw@panix.com
State Superseded
Headers

Commit Message

Zack Weinberg Aug. 28, 2019, 3:32 p.m. UTC
  Remove sysdeps/unix/clock_gettime.c, which implemented clock_gettime
using gettimeofday; new OS ports must provide a real implementation of
clock_gettime.

Rename sysdeps/mach/gettimeofday.c to sysdeps/mach/clock_gettime.c and
convert into an implementation of clock_gettime.  It only supports
CLOCK_REALTIME; Mach does not appear to have any support for monotonic
clocks.  It uses __host_get_time, which provides at best microsecond
resolution.  Hurd is currently using sysdeps/posix/clock_getres.c for
clock_getres; its output for CLOCK_REALTIME is based on
sysconf (_SC_CLK_TCK), and I do not know whether that gives the
correct result.

Most Linux ports supplied a vDSO symbol for gettimeofday, and some
wrapped that with an ifunc, so this patch deletes a lot of code.
For ease of future edits to the many copies of _libc_vdso_platform_setup,
the variable "p" in each is now declared separately from any use of it.

Unlike settimeofday, there are no known uses of gettimeofday's
vestigial "get time zone" feature that are not bugs.  (The per-process
timezone support in localtime and friends is unrelated, and the
programs that set the kernel's offset between the hardware clock and
UTC do not need to read it back.)  Therefore, this feature is dummied
out.  Henceforth, if gettimeofday's "struct timezone" argument is not
NULL, it will write zeroes to both fields.  Any program that is
actually looking at this data will thus think it is running in UTC,
which is probably more correct than whatever it was doing before.

[__]gettimeofday no longer has any internal callers, so we can now
remove its internal prototype and PLT bypass aliases.  The
__gettimeofday@GLIBC_2.0 export remains, in case it is used by any
third-party code.

	* time/gettimeofday.c: No longer a stub implementation.
	Call __clock_gettime.  If tz argument is not NULL, clear the
	object it points to.  Remove libc_hidden_* for __gettimeofday
	and gettimeofday.  Optionally override the default symbol
	version for gettimeofday and __gettimeofday.
	* include/sys/time.h: Remove internal prototype and libc_hidden_proto
	for __gettimeofday, and libc_hidden_proto for gettimeofday.

	* sysdeps/unix/sysv/linux/alpha/gettimeofday.c: Switch to
	including time/gettimeofday.c.

	* sysdeps/unix/sysv/linux/alpha/osf_gettimeofday.c
	(gettimeofday@GLIBC_2.0): Use __clock_gettime instead of __gettimeofday.
	If tz argument is not NULL, clear the object it points to.

	* sysdeps/unix/sysv/linux/aarch64/init-first.c
	* sysdeps/unix/sysv/linux/arm/init-first.c
	* sysdeps/unix/sysv/linux/mips/init-first.c
	* sysdeps/unix/sysv/linux/powerpc/init-first.c
	* sysdeps/unix/sysv/linux/riscv/init-first.c
	* sysdeps/unix/sysv/linux/s390/init-first.c
	* sysdeps/unix/sysv/linux/sparc/init-first.c:
	Do not define nor initialize VDSO_SYMBOL(gettimeofday).

	* sysdeps/unix/sysv/linux/aarch64/libc-vdso.h
	* sysdeps/unix/sysv/linux/arm/libc-vdso.h
	* sysdeps/unix/sysv/linux/mips/libc-vdso.h
	* sysdeps/unix/sysv/linux/powerpc/libc-vdso.h
	* sysdeps/unix/sysv/linux/riscv/libc-vdso.h
	* sysdeps/unix/sysv/linux/s390/libc-vdso.h
	* sysdeps/unix/sysv/linux/sparc/libc-vdso.h:
	Do not declare VDSO_SYMBOL(gettimeofday).

	* sysdeps/unix/syscalls.list: Remove entry for gettimeofday.
	* sysdeps/unix/sysv/linux/alpha/syscalls.list:
	Remove entries for gettimeofday and osf_gettimeofday.
	* sysdeps/unix/sysv/linux/x86_64/x32/syscalls.list:
	Remove entry for gettimeofday.

	* sysdeps/posix/gettimeofday.c
	* sysdeps/unix/clock_gettime.c
	* sysdeps/unix/sysv/linux/aarch64/gettimeofday.c
	* sysdeps/unix/sysv/linux/gettimeofday.c
	* sysdeps/unix/sysv/linux/i386/gettimeofday.c
	* sysdeps/unix/sysv/linux/powerpc/gettimeofday.c
	* sysdeps/unix/sysv/linux/x86/gettimeofday.c: Delete file.

	* sysdeps/mach/gettimeofday.c: Rename to
	sysdeps/mach/clock_gettime.c and convert into an
	implementation of clock_gettime.
---
 include/sys/time.h                            |  4 -
 sysdeps/{unix => mach}/clock_gettime.c        | 37 ++++----
 sysdeps/mach/gettimeofday.c                   | 43 ----------
 sysdeps/posix/gettimeofday.c                  | 67 ---------------
 sysdeps/unix/syscalls.list                    |  1 -
 .../unix/sysv/linux/aarch64/gettimeofday.c    | 71 ----------------
 sysdeps/unix/sysv/linux/aarch64/init-first.c  |  7 +-
 sysdeps/unix/sysv/linux/aarch64/libc-vdso.h   |  2 -
 .../sysv/linux/{i386 => alpha}/gettimeofday.c | 25 ++----
 .../unix/sysv/linux/alpha/osf_gettimeofday.c  | 11 ++-
 sysdeps/unix/sysv/linux/alpha/syscalls.list   |  1 -
 sysdeps/unix/sysv/linux/arm/init-first.c      |  7 +-
 sysdeps/unix/sysv/linux/arm/libc-vdso.h       |  2 -
 sysdeps/unix/sysv/linux/gettimeofday.c        | 49 -----------
 sysdeps/unix/sysv/linux/mips/init-first.c     |  7 +-
 sysdeps/unix/sysv/linux/mips/libc-vdso.h      |  2 -
 .../unix/sysv/linux/powerpc/gettimeofday.c    | 85 -------------------
 sysdeps/unix/sysv/linux/powerpc/init-first.c  |  8 +-
 sysdeps/unix/sysv/linux/powerpc/libc-vdso.h   |  2 -
 sysdeps/unix/sysv/linux/riscv/init-first.c    | 10 +--
 sysdeps/unix/sysv/linux/riscv/libc-vdso.h     |  2 -
 sysdeps/unix/sysv/linux/s390/init-first.c     |  9 +-
 sysdeps/unix/sysv/linux/s390/libc-vdso.h      |  3 -
 sysdeps/unix/sysv/linux/sparc/init-first.c    |  8 +-
 sysdeps/unix/sysv/linux/sparc/libc-vdso.h     |  2 -
 sysdeps/unix/sysv/linux/x86/gettimeofday.c    | 61 -------------
 .../unix/sysv/linux/x86_64/x32/syscalls.list  |  1 -
 time/gettimeofday.c                           | 32 ++++---
 28 files changed, 67 insertions(+), 492 deletions(-)
 rename sysdeps/{unix => mach}/clock_gettime.c (65%)
 delete mode 100644 sysdeps/mach/gettimeofday.c
 delete mode 100644 sysdeps/posix/gettimeofday.c
 delete mode 100644 sysdeps/unix/sysv/linux/aarch64/gettimeofday.c
 rename sysdeps/unix/sysv/linux/{i386 => alpha}/gettimeofday.c (58%)
 delete mode 100644 sysdeps/unix/sysv/linux/gettimeofday.c
 delete mode 100644 sysdeps/unix/sysv/linux/powerpc/gettimeofday.c
 delete mode 100644 sysdeps/unix/sysv/linux/x86/gettimeofday.c
  

Comments

Florian Weimer Aug. 28, 2019, 6:27 p.m. UTC | #1
* Zack Weinberg:

> Remove sysdeps/unix/clock_gettime.c, which implemented clock_gettime
> using gettimeofday; new OS ports must provide a real implementation of
> clock_gettime.

This comes at a performance cost.  On a Xeon Gold 6126 with Fedora 31's
5.3.0-0.rc5.git0.1.fc31 kernel, I see 17.6 ns per gettimeofday call
before this change, and 19.6 ns afterwards.

Part of that is the additional overhead of the functional call and the
clock check.  I think gettimeofday should call directly into the vDSO.

Another part according to profiles is the downscaling of the nanoseconds
value.  TIMESPEC_TO_TIMEVAL does not tell GCC that tv_nsec member does
not use the full long range, so GCC emits a full 64-bit division (with a
multiplication and shift).

Both changes will hopefully recover the performance loss.

Thanks,
Florian
  
Adhemerval Zanella Sept. 2, 2019, 7:31 p.m. UTC | #2
On 28/08/2019 15:27, Florian Weimer wrote:
> * Zack Weinberg:
> 
>> Remove sysdeps/unix/clock_gettime.c, which implemented clock_gettime
>> using gettimeofday; new OS ports must provide a real implementation of
>> clock_gettime.
> 
> This comes at a performance cost.  On a Xeon Gold 6126 with Fedora 31's
> 5.3.0-0.rc5.git0.1.fc31 kernel, I see 17.6 ns per gettimeofday call
> before this change, and 19.6 ns afterwards.
> 
> Part of that is the additional overhead of the functional call and the
> clock check.  I think gettimeofday should call directly into the vDSO.
> 
> Another part according to profiles is the downscaling of the nanoseconds
> value.  TIMESPEC_TO_TIMEVAL does not tell GCC that tv_nsec member does
> not use the full long range, so GCC emits a full 64-bit division (with a
> multiplication and shift).
> 
> Both changes will hopefully recover the performance loss.

As for time patch from this set, I think we can still make the *default*
gettimeofday implementation use the clock_gettime if the architecture
does not have a faster way to accomplish it (through vDSO or the ifunc
trick to reduce latency). It would allow each arch-mantainer to set if
or when the architecture will move generic implementation and cleanup
the optimized glue.

My view is we can use my proposed patch to refactor gettimeofdat [1], and 
change the fallback syscall path to call clock_gettime instead.  I can work
towards the modification.

[1] https://sourceware.org/ml/libc-alpha/2019-07/msg00158.html
  

Patch

diff --git a/include/sys/time.h b/include/sys/time.h
index a57752e8c7..4a91622096 100644
--- a/include/sys/time.h
+++ b/include/sys/time.h
@@ -20,10 +20,6 @@ 
 # include <time/sys/time.h>
 
 # ifndef _ISOMAC
-extern int __gettimeofday (struct timeval *__tv,
-			   struct timezone *__tz);
-libc_hidden_proto (__gettimeofday)
-libc_hidden_proto (gettimeofday)
 extern int __settimezone (const struct timezone *__tz)
 	attribute_hidden;
 extern int __adjtime (const struct timeval *__delta,
diff --git a/sysdeps/unix/clock_gettime.c b/sysdeps/mach/clock_gettime.c
similarity index 65%
rename from sysdeps/unix/clock_gettime.c
rename to sysdeps/mach/clock_gettime.c
index 2a82fc1066..56f518bd16 100644
--- a/sysdeps/unix/clock_gettime.c
+++ b/sysdeps/mach/clock_gettime.c
@@ -1,5 +1,4 @@ 
-/* clock_gettime -- Get the current time from a POSIX clockid_t.  Unix version.
-   Copyright (C) 1999-2019 Free Software Foundation, Inc.
+/* Copyright (C) 1991-2019 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
@@ -18,32 +17,28 @@ 
 
 #include <errno.h>
 #include <time.h>
-#include <sys/time.h>
+#include <mach.h>
 #include <shlib-compat.h>
 
-/* Get current value of CLOCK and store it in TP.  */
+/* Get the current time of day, putting it into *TS.
+   Returns 0 on success, -1 on errors.  */
 int
-__clock_gettime (clockid_t clock_id, struct timespec *tp)
+__clock_gettime (clockid_t clock_id, struct timespec *ts)
 {
-  int retval = -1;
-
-  switch (clock_id)
+  if (clock_id != CLOCK_REALTIME)
     {
-    case CLOCK_REALTIME:
-      {
-	struct timeval tv;
-	retval = __gettimeofday (&tv, NULL);
-	if (retval == 0)
-	  TIMEVAL_TO_TIMESPEC (&tv, tp);
-      }
-      break;
-
-    default:
-      __set_errno (EINVAL);
-      break;
+      errno = EINVAL;
+      return -1;
     }
 
-  return retval;
+  /* __host_get_time can only fail if passed an invalid host_t.
+     __mach_host_self could theoretically fail (producing an
+     invalid host_t) due to resource exhaustion, but we assume
+     this will never happen.  */
+  time_value_t tv;
+  __host_get_time (__mach_host_self (), &tv);
+  TIME_VALUE_TO_TIMESPEC (&tv, ts);
+  return 0;
 }
 libc_hidden_def (__clock_gettime)
 
diff --git a/sysdeps/mach/gettimeofday.c b/sysdeps/mach/gettimeofday.c
deleted file mode 100644
index 8d0dfbb7dc..0000000000
--- a/sysdeps/mach/gettimeofday.c
+++ /dev/null
@@ -1,43 +0,0 @@ 
-/* Copyright (C) 1991-2019 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 <stddef.h>
-#include <sys/time.h>
-#include <mach.h>
-
-/* Get the current time of day and timezone information,
-   putting it into *TV and *TZ.  If TZ is NULL, *TZ is not filled.
-   Returns 0 on success, -1 on errors.  */
-int
-__gettimeofday (struct timeval *tv, struct timezone *tz)
-{
-  kern_return_t err;
-
-  if (tz != NULL)
-    *tz = (struct timezone){0, 0}; /* XXX */
-
-  if (err = __host_get_time (__mach_host_self (), (time_value_t *) tv))
-    {
-      errno = err;
-      return -1;
-    }
-  return 0;
-}
-libc_hidden_def (__gettimeofday)
-weak_alias (__gettimeofday, gettimeofday)
-libc_hidden_weak (gettimeofday)
diff --git a/sysdeps/posix/gettimeofday.c b/sysdeps/posix/gettimeofday.c
deleted file mode 100644
index 6ba625e13e..0000000000
--- a/sysdeps/posix/gettimeofday.c
+++ /dev/null
@@ -1,67 +0,0 @@ 
-/* Copyright (C) 1991-2019 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 <time.h>
-#include <sys/time.h>
-
-/* Get the current time of day and timezone information,
-   putting it into *TV and *TZ.  If TZ is NULL, *TZ is not filled.
-   Returns 0 on success, -1 on errors.  */
-int
-__gettimeofday (struct timeval *tv, struct timezone *tz)
-{
-  if (tv == NULL)
-    {
-      __set_errno (EINVAL);
-      return -1;
-    }
-
-  tv->tv_sec = (long int) time ((time_t *) NULL);
-  tv->tv_usec = 0L;
-
-  if (tz != NULL)
-    {
-      const time_t timer = tv->tv_sec;
-      struct tm tm;
-      const struct tm *tmp;
-
-      const long int save_timezone = __timezone;
-      const long int save_daylight = __daylight;
-      char *save_tzname[2];
-      save_tzname[0] = __tzname[0];
-      save_tzname[1] = __tzname[1];
-
-      tmp = localtime_r (&timer, &tm);
-
-      tz->tz_minuteswest = __timezone / 60;
-      tz->tz_dsttime = __daylight;
-
-      __timezone = save_timezone;
-      __daylight = save_daylight;
-      __tzname[0] = save_tzname[0];
-      __tzname[1] = save_tzname[1];
-
-      if (tmp == NULL)
-	return -1;
-    }
-
-  return 0;
-}
-libc_hidden_def (__gettimeofday)
-weak_alias (__gettimeofday, gettimeofday)
-libc_hidden_weak (gettimeofday)
diff --git a/sysdeps/unix/syscalls.list b/sysdeps/unix/syscalls.list
index 5fedd5733d..e28e801c7a 100644
--- a/sysdeps/unix/syscalls.list
+++ b/sysdeps/unix/syscalls.list
@@ -33,7 +33,6 @@  getrlimit	-	getrlimit	i:ip	__getrlimit	getrlimit
 getrusage	-	getrusage	i:ip	__getrusage	getrusage
 getsockname	-	getsockname	i:ibN	__getsockname	getsockname
 getsockopt	-	getsockopt	i:iiiBN	getsockopt
-gettimeofday	-	gettimeofday	i:pP	__gettimeofday	gettimeofday
 getuid		-	getuid		Ei:	__getuid	getuid
 ioctl		-	ioctl		i:iiI	__ioctl		ioctl
 kill		-	kill		i:ii	__kill		kill
diff --git a/sysdeps/unix/sysv/linux/aarch64/gettimeofday.c b/sysdeps/unix/sysv/linux/aarch64/gettimeofday.c
deleted file mode 100644
index 9180b50bf7..0000000000
--- a/sysdeps/unix/sysv/linux/aarch64/gettimeofday.c
+++ /dev/null
@@ -1,71 +0,0 @@ 
-/* Copyright (C) 2018-2019 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/>.  */
-
-/* Get the current time of day and timezone information,
-   putting it into *tv and *tz.  If tz is null, *tz is not filled.
-   Returns 0 on success, -1 on errors.  */
-
-#ifdef SHARED
-
-# define __gettimeofday __redirect___gettimeofday
-# include <sys/time.h>
-# undef __gettimeofday
-# define HAVE_VSYSCALL
-# include <dl-vdso.h>
-# include <sysdep-vdso.h>
-
-/* Used as a fallback in the ifunc resolver if VDSO is not available
-   and for libc.so internal __gettimeofday calls.  */
-
-static int
-__gettimeofday_vsyscall (struct timeval *tv, struct timezone *tz)
-{
-  return INLINE_VSYSCALL (gettimeofday, 2, tv, tz);
-}
-
-/* PREPARE_VERSION_KNOWN will need an __LP64__ ifdef when ILP32 support
-   goes in.  See _libc_vdso_platform_setup in
-   sysdeps/unix/sysv/linux/aarch64/init-first.c.  */
-
-# undef INIT_ARCH
-# define INIT_ARCH() \
-	   PREPARE_VERSION_KNOWN (linux_version, LINUX_2_6_39); \
-	   void *vdso_gettimeofday = \
-	     _dl_vdso_vsym ("__kernel_gettimeofday", &linux_version);
-
-libc_ifunc_hidden (__redirect___gettimeofday, __gettimeofday,
-		   vdso_gettimeofday ?: (void *) __gettimeofday_vsyscall)
-
-__hidden_ver1 (__gettimeofday_vsyscall, __GI___gettimeofday,
-	       __gettimeofday_vsyscall);
-
-#else
-
-# include <sys/time.h>
-# include <sysdep.h>
-int
-__gettimeofday (struct timeval *tv, struct timezone *tz)
-{
-  return INLINE_SYSCALL (gettimeofday, 2, tv, tz);
-}
-libc_hidden_def (__gettimeofday)
-
-#endif
-
-weak_alias (__gettimeofday, gettimeofday)
-libc_hidden_weak (gettimeofday)
diff --git a/sysdeps/unix/sysv/linux/aarch64/init-first.c b/sysdeps/unix/sysv/linux/aarch64/init-first.c
index 80f7ed91ef..5e4e1fbf8c 100644
--- a/sysdeps/unix/sysv/linux/aarch64/init-first.c
+++ b/sysdeps/unix/sysv/linux/aarch64/init-first.c
@@ -19,23 +19,20 @@ 
 #include <dl-vdso.h>
 #include <libc-vdso.h>
 
-int (*VDSO_SYMBOL(gettimeofday)) (struct timeval *, void *) attribute_hidden;
 int (*VDSO_SYMBOL(clock_gettime)) (clockid_t, struct timespec *);
 int (*VDSO_SYMBOL(clock_getres)) (clockid_t, struct timespec *);
 
 static inline void
 _libc_vdso_platform_setup (void)
 {
+  void *p;
+
 #ifdef __LP64__
   PREPARE_VERSION_KNOWN (linux_version, LINUX_2_6_39);
 #else
   PREPARE_VERSION_KNOWN (linux_version, LINUX_4_9);
 #endif
 
-  void *p = _dl_vdso_vsym ("__kernel_gettimeofday", &linux_version);
-  PTR_MANGLE (p);
-  VDSO_SYMBOL(gettimeofday) = p;
-
   p = _dl_vdso_vsym ("__kernel_clock_gettime", &linux_version);
   PTR_MANGLE (p);
   VDSO_SYMBOL(clock_gettime) = p;
diff --git a/sysdeps/unix/sysv/linux/aarch64/libc-vdso.h b/sysdeps/unix/sysv/linux/aarch64/libc-vdso.h
index 3fcbaa9fce..285ca62fd3 100644
--- a/sysdeps/unix/sysv/linux/aarch64/libc-vdso.h
+++ b/sysdeps/unix/sysv/linux/aarch64/libc-vdso.h
@@ -22,8 +22,6 @@ 
 #include <sysdep.h>
 #include <sysdep-vdso.h>
 
-extern int (*VDSO_SYMBOL(gettimeofday)) (struct timeval *, void *)
-   attribute_hidden;
 extern int (*VDSO_SYMBOL(clock_gettime)) (clockid_t, struct timespec *);
 extern int (*VDSO_SYMBOL(clock_getres)) (clockid_t, struct timespec *);
 
diff --git a/sysdeps/unix/sysv/linux/i386/gettimeofday.c b/sysdeps/unix/sysv/linux/alpha/gettimeofday.c
similarity index 58%
rename from sysdeps/unix/sysv/linux/i386/gettimeofday.c
rename to sysdeps/unix/sysv/linux/alpha/gettimeofday.c
index 185450ece6..46dc778427 100644
--- a/sysdeps/unix/sysv/linux/i386/gettimeofday.c
+++ b/sysdeps/unix/sysv/linux/alpha/gettimeofday.c
@@ -1,5 +1,5 @@ 
-/* gettimeofday - get the time.  Linux/i386 version.
-   Copyright (C) 2015-2019 Free Software Foundation, Inc.
+/* gettimeofday -- Get the current time of day.  Linux/Alpha/tv64 version.
+   Copyright (C) 2019 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
@@ -16,20 +16,7 @@ 
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-#ifdef SHARED
-# define __gettimeofday __redirect___gettimeofday
-#endif
-
-#include <sys/time.h>
-
-#ifdef SHARED
-# undef __gettimeofday
-# define __gettimeofday_type __redirect___gettimeofday
-
-# undef libc_hidden_def
-# define libc_hidden_def(name) \
-  __hidden_ver1 (__gettimeofday_syscall, __GI___gettimeofday, \
-	       __gettimeofday_syscall);
-#endif
-
-#include <sysdeps/unix/sysv/linux/x86/gettimeofday.c>
+/* We can use the generic implementation, but we have to override its
+   default symbol version.  */
+#define VERSION_gettimeofday GLIBC_2.1
+#include <time/gettimeofday.c>
diff --git a/sysdeps/unix/sysv/linux/alpha/osf_gettimeofday.c b/sysdeps/unix/sysv/linux/alpha/osf_gettimeofday.c
index 5122f7edac..5ff890d1ca 100644
--- a/sysdeps/unix/sysv/linux/alpha/osf_gettimeofday.c
+++ b/sysdeps/unix/sysv/linux/alpha/osf_gettimeofday.c
@@ -20,6 +20,8 @@ 
 
 #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1)
 
+#include <string.h>
+#include <time.h>
 #include <sys/time.h>
 #include <tv32-compat.h>
 
@@ -30,10 +32,13 @@  int
 attribute_compat_text_section
 __gettimeofday_tv32 (struct timeval32 *restrict tv32, void *restrict tz)
 {
-  struct timeval tv;
-  __gettimeofday (&tv, tz);
+  if (__glibc_unlikely (tz != 0))
+    memset (tz, 0, sizeof (struct timezone));
 
-  TV64_TO_TV32 (tv32, &tv);
+  struct timespec ts;
+  __clock_gettime (CLOCK_REALTIME, &ts);
+
+  TS64_TO_TV32 (tv32, &ts);
   return 0;
 }
 
diff --git a/sysdeps/unix/sysv/linux/alpha/syscalls.list b/sysdeps/unix/sysv/linux/alpha/syscalls.list
index 95a27e18e8..7cb51f9f4d 100644
--- a/sysdeps/unix/sysv/linux/alpha/syscalls.list
+++ b/sysdeps/unix/sysv/linux/alpha/syscalls.list
@@ -23,7 +23,6 @@  pciconfig_write	EXTRA	pciconfig_write	5	pciconfig_write
 pciconfig_iobase EXTRA	pciconfig_iobase 3	__pciconfig_iobase pciconfig_iobase
 
 # timeval64 entry points (see osf_*.c for GLIBC_2.0 timeval32 equivalents)
-gettimeofday	-	gettimeofday	i:pP	__GI___gettimeofday gettimeofday@@GLIBC_2.1 __gettimeofday@@GLIBC_2.1
 getitimer	-	getitimer	i:ip	__getitimer	getitimer@@GLIBC_2.1
 setitimer	-	setitimer	i:ipP	__setitimer	setitimer@@GLIBC_2.1
 utimes		-	utimes		i:sp	__utimes	utimes@@GLIBC_2.1
diff --git a/sysdeps/unix/sysv/linux/arm/init-first.c b/sysdeps/unix/sysv/linux/arm/init-first.c
index e1846df661..c73970d06d 100644
--- a/sysdeps/unix/sysv/linux/arm/init-first.c
+++ b/sysdeps/unix/sysv/linux/arm/init-first.c
@@ -21,17 +21,14 @@ 
 #include <libc-vdso.h>
 #include <sysdep-vdso.h>
 
-int (*VDSO_SYMBOL(gettimeofday)) (struct timeval *, void *) attribute_hidden;
 int (*VDSO_SYMBOL(clock_gettime)) (clockid_t, struct timespec *);
 
 static inline void
 _libc_vdso_platform_setup (void)
 {
-  PREPARE_VERSION_KNOWN (linux26, LINUX_2_6);
+  void *p;
 
-  void *p = _dl_vdso_vsym ("__vdso_gettimeofday", &linux26);
-  PTR_MANGLE (p);
-  VDSO_SYMBOL (gettimeofday) = p;
+  PREPARE_VERSION_KNOWN (linux26, LINUX_2_6);
 
   p = _dl_vdso_vsym ("__vdso_clock_gettime", &linux26);
   PTR_MANGLE (p);
diff --git a/sysdeps/unix/sysv/linux/arm/libc-vdso.h b/sysdeps/unix/sysv/linux/arm/libc-vdso.h
index 8702165c6b..b7ae61def6 100644
--- a/sysdeps/unix/sysv/linux/arm/libc-vdso.h
+++ b/sysdeps/unix/sysv/linux/arm/libc-vdso.h
@@ -22,8 +22,6 @@ 
 
 #include <sysdep-vdso.h>
 
-extern int (*VDSO_SYMBOL(gettimeofday)) (struct timeval *, void *)
-   attribute_hidden;
 extern int (*VDSO_SYMBOL(clock_gettime)) (clockid_t, struct timespec *);
 
 #endif /* _LIBC_VDSO_H */
diff --git a/sysdeps/unix/sysv/linux/gettimeofday.c b/sysdeps/unix/sysv/linux/gettimeofday.c
deleted file mode 100644
index 0c86245981..0000000000
--- a/sysdeps/unix/sysv/linux/gettimeofday.c
+++ /dev/null
@@ -1,49 +0,0 @@ 
-/* Copyright (C) 2015-2019 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 <sys/time.h>
-
-#undef __gettimeofday
-
-#ifdef HAVE_GETTIMEOFDAY_VSYSCALL
-# define HAVE_VSYSCALL
-#endif
-#include <sysdep-vdso.h>
-
-/* Get the current time of day and timezone information,
-   putting it into *tv and *tz.  If tz is null, *tz is not filled.
-   Returns 0 on success, -1 on errors.  */
-int
-___gettimeofday (struct timeval *tv, struct timezone *tz)
-{
-  return INLINE_VSYSCALL (gettimeofday, 2, tv, tz);
-}
-
-#ifdef VERSION_gettimeofday
-weak_alias (___gettimeofday, __wgettimeofday);
-default_symbol_version (___gettimeofday, __gettimeofday, VERSION_gettimeofday);
-default_symbol_version (__wgettimeofday,   gettimeofday, VERSION_gettimeofday);
-libc_hidden_ver (___gettimeofday, __gettimeofday);
-libc_hidden_ver (___gettimeofday, gettimeofday);
-#else
-strong_alias (___gettimeofday, __gettimeofday)
-weak_alias (___gettimeofday, gettimeofday)
-libc_hidden_def (__gettimeofday)
-libc_hidden_weak (gettimeofday)
-#endif
diff --git a/sysdeps/unix/sysv/linux/mips/init-first.c b/sysdeps/unix/sysv/linux/mips/init-first.c
index 25884ffd80..a7c3643cb8 100644
--- a/sysdeps/unix/sysv/linux/mips/init-first.c
+++ b/sysdeps/unix/sysv/linux/mips/init-first.c
@@ -20,17 +20,14 @@ 
 #include <dl-vdso.h>
 #include <libc-vdso.h>
 
-int (*VDSO_SYMBOL(gettimeofday)) (struct timeval *, void *) attribute_hidden;
 int (*VDSO_SYMBOL(clock_gettime)) (clockid_t, struct timespec *);
 
 static inline void
 _libc_vdso_platform_setup (void)
 {
-  PREPARE_VERSION_KNOWN (linux26, LINUX_2_6);
+  void *p;
 
-  void *p = _dl_vdso_vsym ("__vdso_gettimeofday", &linux26);
-  PTR_MANGLE (p);
-  VDSO_SYMBOL (gettimeofday) = p;
+  PREPARE_VERSION_KNOWN (linux26, LINUX_2_6);
 
   p = _dl_vdso_vsym ("__vdso_clock_gettime", &linux26);
   PTR_MANGLE (p);
diff --git a/sysdeps/unix/sysv/linux/mips/libc-vdso.h b/sysdeps/unix/sysv/linux/mips/libc-vdso.h
index 344ea2d750..e0a8fe4a80 100644
--- a/sysdeps/unix/sysv/linux/mips/libc-vdso.h
+++ b/sysdeps/unix/sysv/linux/mips/libc-vdso.h
@@ -22,8 +22,6 @@ 
 
 #include <sysdep-vdso.h>
 
-extern int (*VDSO_SYMBOL(gettimeofday)) (struct timeval *, void *)
-   attribute_hidden;
 extern int (*VDSO_SYMBOL(clock_gettime)) (clockid_t, struct timespec *);
 
 #endif /* _LIBC_VDSO_H */
diff --git a/sysdeps/unix/sysv/linux/powerpc/gettimeofday.c b/sysdeps/unix/sysv/linux/powerpc/gettimeofday.c
deleted file mode 100644
index 463b678ad9..0000000000
--- a/sysdeps/unix/sysv/linux/powerpc/gettimeofday.c
+++ /dev/null
@@ -1,85 +0,0 @@ 
-/* Copyright (C) 2005-2019 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/>.  */
-
-#if defined SHARED && !defined __powerpc64__
-# define __gettimeofday __redirect___gettimeofday
-#else
-# define __redirect___gettimeofday __gettimeofday
-#endif
-
-#include <sys/time.h>
-
-#ifdef SHARED
-
-# include <dl-vdso.h>
-# include <libc-vdso.h>
-# include <dl-machine.h>
-
-# ifndef __powerpc64__
-#  undef __gettimeofday
-
-int
-__gettimeofday_vsyscall (struct timeval *tv, struct timezone *tz)
-{
-  return INLINE_VSYSCALL (gettimeofday, 2, tv, tz);
-}
-
-/* __GI___gettimeofday is defined as hidden and for ppc32 it enables the
-   compiler make a local call (symbol@local) for internal GLIBC usage. It
-   means the PLT won't be used and the ifunc resolver will be called directly.
-   For ppc64 a call to a function in another translation unit might use a
-   different toc pointer thus disallowing direct branchess and making internal
-   ifuncs calls safe.  */
-#  undef libc_hidden_def
-#  define libc_hidden_def(name)					\
-  __hidden_ver1 (__gettimeofday_vsyscall, __GI___gettimeofday,	\
-	       __gettimeofday_vsyscall);
-
-# endif /* !__powerpc64__  */
-
-static int
-__gettimeofday_syscall (struct timeval *tv, struct timezone *tz)
-{
-  return INLINE_SYSCALL (gettimeofday, 2, tv, tz);
-}
-
-# define INIT_ARCH()						\
-  PREPARE_VERSION_KNOWN (linux2615, LINUX_2_6_15);		\
-  void *vdso_gettimeofday = _dl_vdso_vsym ("__kernel_gettimeofday", &linux2615);
-
-/* If the vDSO is not available we fall back syscall.  */
-libc_ifunc_hidden (__redirect___gettimeofday, __gettimeofday,
-		   vdso_gettimeofday
-		   ? VDSO_IFUNC_RET (vdso_gettimeofday)
-		   : (void *) __gettimeofday_syscall);
-libc_hidden_def (__gettimeofday)
-
-#else
-
-# include <sysdep.h>
-# include <errno.h>
-
-int
-__gettimeofday (struct timeval *tv, struct timezone *tz)
-{
-  return INLINE_SYSCALL (gettimeofday, 2, tv, tz);
-}
-libc_hidden_def (__gettimeofday)
-
-#endif
-weak_alias (__gettimeofday, gettimeofday)
-libc_hidden_weak (gettimeofday)
diff --git a/sysdeps/unix/sysv/linux/powerpc/init-first.c b/sysdeps/unix/sysv/linux/powerpc/init-first.c
index 4f12b59e76..166bf3f2fe 100644
--- a/sysdeps/unix/sysv/linux/powerpc/init-first.c
+++ b/sysdeps/unix/sysv/linux/powerpc/init-first.c
@@ -19,8 +19,6 @@ 
 #include <dl-vdso.h>
 #include <libc-vdso.h>
 
-int (*VDSO_SYMBOL(gettimeofday)) (struct timeval *, void *)
-  attribute_hidden;
 int (*VDSO_SYMBOL(clock_gettime)) (clockid_t, struct timespec *);
 int (*VDSO_SYMBOL(clock_getres)) (clockid_t, struct timespec *);
 unsigned long long (*VDSO_SYMBOL(get_tbfreq)) (void);
@@ -36,11 +34,9 @@  void *VDSO_SYMBOL(sigtramp_rt32);
 static inline void
 _libc_vdso_platform_setup (void)
 {
-  PREPARE_VERSION_KNOWN (linux2615, LINUX_2_6_15);
+  void *p;
 
-  void *p = _dl_vdso_vsym ("__kernel_gettimeofday", &linux2615);
-  PTR_MANGLE (p);
-  VDSO_SYMBOL (gettimeofday) = p;
+  PREPARE_VERSION_KNOWN (linux2615, LINUX_2_6_15);
 
   p = _dl_vdso_vsym ("__kernel_clock_gettime", &linux2615);
   PTR_MANGLE (p);
diff --git a/sysdeps/unix/sysv/linux/powerpc/libc-vdso.h b/sysdeps/unix/sysv/linux/powerpc/libc-vdso.h
index f8184061c0..e233ea18a5 100644
--- a/sysdeps/unix/sysv/linux/powerpc/libc-vdso.h
+++ b/sysdeps/unix/sysv/linux/powerpc/libc-vdso.h
@@ -23,8 +23,6 @@ 
 #include <sysdep.h>
 #include <sysdep-vdso.h>
 
-extern int (*VDSO_SYMBOL(gettimeofday)) (struct timeval *, void *)
-  attribute_hidden;
 extern int (*VDSO_SYMBOL(clock_gettime)) (clockid_t, struct timespec *);
 extern int (*VDSO_SYMBOL(clock_getres)) (clockid_t, struct timespec *);
 extern unsigned long long (*VDSO_SYMBOL(get_tbfreq)) (void);
diff --git a/sysdeps/unix/sysv/linux/riscv/init-first.c b/sysdeps/unix/sysv/linux/riscv/init-first.c
index 98a8ce33ad..014d770861 100644
--- a/sysdeps/unix/sysv/linux/riscv/init-first.c
+++ b/sysdeps/unix/sysv/linux/riscv/init-first.c
@@ -22,8 +22,6 @@ 
 
 long int (*VDSO_SYMBOL (getcpu)) (unsigned int *, unsigned int *, void *)
     attribute_hidden;
-long int (*VDSO_SYMBOL (gettimeofday)) (struct timeval *, void *)
-    attribute_hidden;
 long int (*VDSO_SYMBOL (clock_gettime)) (clockid_t, struct timespec *)
     attribute_hidden;
 long int (*VDSO_SYMBOL (clock_getres)) (clockid_t, struct timespec *)
@@ -32,16 +30,14 @@  long int (*VDSO_SYMBOL (clock_getres)) (clockid_t, struct timespec *)
 static inline void
 _libc_vdso_platform_setup (void)
 {
+  void *p;
+
   PREPARE_VERSION_KNOWN (linux_version, LINUX_4_15);
 
-  void *p = _dl_vdso_vsym ("__vdso_getcpu", &linux_version);
+  p = _dl_vdso_vsym ("__vdso_getcpu", &linux_version);
   PTR_MANGLE (p);
   VDSO_SYMBOL (getcpu) = p;
 
-  p = _dl_vdso_vsym ("__vdso_gettimeofday", &linux_version);
-  PTR_MANGLE (p);
-  VDSO_SYMBOL (gettimeofday) = p;
-
   p = _dl_vdso_vsym ("__vdso_clock_gettime", &linux_version);
   PTR_MANGLE (p);
   VDSO_SYMBOL (clock_gettime) = p;
diff --git a/sysdeps/unix/sysv/linux/riscv/libc-vdso.h b/sysdeps/unix/sysv/linux/riscv/libc-vdso.h
index 2373292ab9..e9a5b239b9 100644
--- a/sysdeps/unix/sysv/linux/riscv/libc-vdso.h
+++ b/sysdeps/unix/sysv/linux/riscv/libc-vdso.h
@@ -24,8 +24,6 @@ 
 
 extern long int (*VDSO_SYMBOL (getcpu)) (unsigned int *, unsigned int *, void *)
     attribute_hidden;
-extern long int (*VDSO_SYMBOL (gettimeofday)) (struct timeval *, void *)
-    attribute_hidden;
 extern long int (*VDSO_SYMBOL (clock_gettime)) (clockid_t, struct timespec *)
     attribute_hidden;
 extern long int (*VDSO_SYMBOL (clock_getres)) (clockid_t, struct timespec *)
diff --git a/sysdeps/unix/sysv/linux/s390/init-first.c b/sysdeps/unix/sysv/linux/s390/init-first.c
index a1ad9458e3..3a55935886 100644
--- a/sysdeps/unix/sysv/linux/s390/init-first.c
+++ b/sysdeps/unix/sysv/linux/s390/init-first.c
@@ -19,9 +19,6 @@ 
 #include <dl-vdso.h>
 #include <libc-vdso.h>
 
-long int (*VDSO_SYMBOL(gettimeofday)) (struct timeval *, void *)
-   attribute_hidden;
-
 long int (*VDSO_SYMBOL(clock_gettime)) (clockid_t, struct timespec *)
   __attribute__ ((nocommon));
 
@@ -34,11 +31,9 @@  long int (*VDSO_SYMBOL(getcpu)) (unsigned *, unsigned *, void *)
 static inline void
 _libc_vdso_platform_setup (void)
 {
-  PREPARE_VERSION_KNOWN (linux2629, LINUX_2_6_29);
+  void *p;
 
-  void *p = _dl_vdso_vsym ("__kernel_gettimeofday", &linux2629);
-  PTR_MANGLE (p);
-  VDSO_SYMBOL (gettimeofday) = p;
+  PREPARE_VERSION_KNOWN (linux2629, LINUX_2_6_29);
 
   p = _dl_vdso_vsym ("__kernel_clock_gettime", &linux2629);
   PTR_MANGLE (p);
diff --git a/sysdeps/unix/sysv/linux/s390/libc-vdso.h b/sysdeps/unix/sysv/linux/s390/libc-vdso.h
index cc97601383..2cdf44583a 100644
--- a/sysdeps/unix/sysv/linux/s390/libc-vdso.h
+++ b/sysdeps/unix/sysv/linux/s390/libc-vdso.h
@@ -22,9 +22,6 @@ 
 
 #include <sysdep-vdso.h>
 
-extern long int (*VDSO_SYMBOL(gettimeofday)) (struct timeval *, void *)
-   attribute_hidden;
-
 extern long int (*VDSO_SYMBOL(clock_gettime)) (clockid_t, struct timespec *);
 
 extern long int (*VDSO_SYMBOL(clock_getres)) (clockid_t, struct timespec *);
diff --git a/sysdeps/unix/sysv/linux/sparc/init-first.c b/sysdeps/unix/sysv/linux/sparc/init-first.c
index 643d6c7c88..520fc25808 100644
--- a/sysdeps/unix/sysv/linux/sparc/init-first.c
+++ b/sysdeps/unix/sysv/linux/sparc/init-first.c
@@ -20,19 +20,15 @@ 
 #include <dl-vdso.h>
 #include <libc-vdso.h>
 
-long int (*VDSO_SYMBOL (gettimeofday)) (struct timeval *, void *)
-    attribute_hidden;
 long int (*VDSO_SYMBOL (clock_gettime)) (clockid_t, struct timespec *)
     attribute_hidden;
 
 static inline void
 _libc_vdso_platform_setup (void)
 {
-  PREPARE_VERSION_KNOWN (linux_version, LINUX_2_6);
+  void *p;
 
-  void *p = _dl_vdso_vsym ("__vdso_gettimeofday", &linux_version);
-  PTR_MANGLE (p);
-  VDSO_SYMBOL (gettimeofday) = p;
+  PREPARE_VERSION_KNOWN (linux_version, LINUX_2_6);
 
   p = _dl_vdso_vsym ("__vdso_clock_gettime", &linux_version);
   PTR_MANGLE (p);
diff --git a/sysdeps/unix/sysv/linux/sparc/libc-vdso.h b/sysdeps/unix/sysv/linux/sparc/libc-vdso.h
index d20afcdf04..28d1229587 100644
--- a/sysdeps/unix/sysv/linux/sparc/libc-vdso.h
+++ b/sysdeps/unix/sysv/linux/sparc/libc-vdso.h
@@ -22,8 +22,6 @@ 
 
 #include <sysdep-vdso.h>
 
-extern long int (*VDSO_SYMBOL(gettimeofday)) (struct timeval *, void *)
-   attribute_hidden;
 extern long int (*VDSO_SYMBOL(clock_gettime)) (clockid_t, struct timespec *);
 
 #endif /* _LIBC_VDSO_H */
diff --git a/sysdeps/unix/sysv/linux/x86/gettimeofday.c b/sysdeps/unix/sysv/linux/x86/gettimeofday.c
deleted file mode 100644
index 8886ccd707..0000000000
--- a/sysdeps/unix/sysv/linux/x86/gettimeofday.c
+++ /dev/null
@@ -1,61 +0,0 @@ 
-/* gettimeofday - get the time.  Linux/x86 version.
-   Copyright (C) 2015-2019 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 <sys/time.h>
-
-#ifdef SHARED
-
-# include <dl-vdso.h>
-# include <errno.h>
-
-static int
-__gettimeofday_syscall (struct timeval *tv, struct timezone *tz)
-{
-  return INLINE_SYSCALL (gettimeofday, 2, tv, tz);
-}
-
-# ifndef __gettimeofday_type
-/* The i386 gettimeofday.c includes this file with a defined
-   __gettimeofday_type macro.  For x86_64 we have to define it to __gettimeofday
-   as the internal symbol is the ifunc'ed one.  */
-#  define __gettimeofday_type __gettimeofday
-# endif
-
-# undef INIT_ARCH
-# define INIT_ARCH() PREPARE_VERSION_KNOWN (linux26, LINUX_2_6)
-/* If the vDSO is not available we fall back to syscall.  */
-libc_ifunc_hidden (__gettimeofday_type, __gettimeofday,
-		   (_dl_vdso_vsym ("__vdso_gettimeofday", &linux26)
-		    ?: &__gettimeofday_syscall))
-libc_hidden_def (__gettimeofday)
-
-#else
-
-# include <sysdep.h>
-# include <errno.h>
-
-int
-__gettimeofday (struct timeval *tv, struct timezone *tz)
-{
-  return INLINE_SYSCALL (gettimeofday, 2, tv, tz);
-}
-libc_hidden_def (__gettimeofday)
-
-#endif
-weak_alias (__gettimeofday, gettimeofday)
-libc_hidden_weak (gettimeofday)
diff --git a/sysdeps/unix/sysv/linux/x86_64/x32/syscalls.list b/sysdeps/unix/sysv/linux/x86_64/x32/syscalls.list
index c0cfa7b0da..58ea31d1fd 100644
--- a/sysdeps/unix/sysv/linux/x86_64/x32/syscalls.list
+++ b/sysdeps/unix/sysv/linux/x86_64/x32/syscalls.list
@@ -1,5 +1,4 @@ 
 # File name	Caller	Syscall name	# args	Strong name	Weak names
 
-gettimeofday	-	gettimeofday:__vdso_gettimeofday@LINUX_2.6	i:pP	__gettimeofday	gettimeofday
 personality	EXTRA	personality	Ei:i	__personality	personality
 posix_fadvise64	-	fadvise64	Vi:iiii	posix_fadvise	posix_fadvise64
diff --git a/time/gettimeofday.c b/time/gettimeofday.c
index 1004ec8911..c4f642631f 100644
--- a/time/gettimeofday.c
+++ b/time/gettimeofday.c
@@ -15,20 +15,32 @@ 
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-#include <errno.h>
+#include <string.h>
+#include <time.h>
 #include <sys/time.h>
 
-/* Get the current time of day and timezone information,
-   putting it into *TV and *TZ.  If TZ is NULL, *TZ is not filled.
+/* Get the current time of day, putting it into *TV.
+   If *TZ is not NULL, clear it.
    Returns 0 on success, -1 on errors.  */
 int
-__gettimeofday (struct timeval *tv, struct timezone *tz)
+___gettimeofday (struct timeval *tv, struct timezone *tz)
 {
-  __set_errno (ENOSYS);
-  return -1;
+  if (__glibc_unlikely (tz != 0))
+    memset (tz, 0, sizeof *tz);
+
+  struct timespec ts;
+  if (__clock_gettime (CLOCK_REALTIME, &ts))
+    return -1;
+
+  TIMESPEC_TO_TIMEVAL (tv, &ts);
+  return 0;
 }
-libc_hidden_def (__gettimeofday)
-weak_alias (__gettimeofday, gettimeofday)
-libc_hidden_weak (gettimeofday)
 
-stub_warning (gettimeofday)
+#ifdef VERSION_gettimeofday
+weak_alias (___gettimeofday, __wgettimeofday);
+default_symbol_version (___gettimeofday, __gettimeofday, VERSION_gettimeofday);
+default_symbol_version (__wgettimeofday,   gettimeofday, VERSION_gettimeofday);
+#else
+strong_alias (___gettimeofday, __gettimeofday)
+weak_alias (___gettimeofday, gettimeofday)
+#endif