Use clock_gettime to implement gettimeofday.

Consolidate generic gettimeofday implementation to use clock_gettime.
Linux ports that still provide gettimeofday through vDSO are not
changed.

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.

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.

It also allows to simplify the arch-specific implementation on x86 and
powerpc to remove the hack to disable the internal route to non iFUNC
variant for internal symbol.

This patch also fixes a missing optimization on aarch64, powerpc, and
x86 where the code used on static build do not use the vDSO.

Checked on x86_64-linux-gnu, i686-linux-gnu, powerpc64le-linux-gnu,
powerpc64-linux-gnu, powerpc-linux-gnu, and aarch64-linux-gnu.

Co-authored-by: Zack Weinberg <zackw@panix.com>
Reviewed-by: Lukasz Majewski <lukma@denx.de>

NEWS

@@ -21,6 +21,19 @@ Major new features:
   18661-1:2014 and TS 18661-3:2015 as amended by the resolution of
   Clarification Request 13 to TS 18661-3.
 
+* The gettimeofday function will no longer report information about a
+  system-wide time zone, expect for aarch64, powerpc, and x86 on Linux
+  which still uses the vDSO symbol (when available).
+
+  This 4.2-BSD-era feature has been deprecated for many years, as it cannot
+  handle the full complexity of the world's timezones, but hitherto we have
+  supported it on a best-effort basis.  Changes required to support 64-bit
+  time_t on 32-bit architectures have made this no longer practical.
+
+  As of this release, callers of gettimeofday with a non-null 'tzp' argument
+  will always receive a 'struct timezone' whose tz_minuteswest and
+  tz_dsttime fields are zero.
+
 Deprecated and removed features, and other changes affecting compatibility:
 
 * The totalorder and totalordermag functions, and the corresponding

include/sys/time.h

@@ -22,8 +22,6 @@
 # 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,

sysdeps/mach/clock_gettime.c

@@ -1,5 +1,4 @@
-/* clock_gettime -- Get the current time from a POSIX clockid_t.  Unix version.
+/* Copyright (C) 1991-2019 Free Software Foundation, Inc.
-   Copyright (C) 1999-2019 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;
+  if (clock_id != CLOCK_REALTIME)
-
-  switch (clock_id)
     {
-    case CLOCK_REALTIME:
+      errno = EINVAL;
-      {
+      return -1;
-	struct timeval tv;
-	retval = __gettimeofday (&tv, NULL);
-	if (retval == 0)
-	  TIMEVAL_TO_TIMESPEC (&tv, tp);
-      }
-      break;
-
-    default:
-      __set_errno (EINVAL);
-      break;
     }
 
-  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)
 

sysdeps/mach/gettimeofday.c

@@ -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
-   <https://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)

sysdeps/posix/gettimeofday.c

@@ -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
-   <https://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)

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

sysdeps/unix/sysv/linux/aarch64/gettimeofday.c

@@ -20,39 +20,39 @@
    putting it into *tv and *tz.  If tz is null, *tz is not filled.
    Returns 0 on success, -1 on errors.  */
 
-#include <sys/time.h>
+#include <time.h>
+#include <sysdep.h>
 
-#ifdef SHARED
+#ifdef HAVE_GETTIMEOFDAY_VSYSCALL
-
+# define HAVE_VSYSCALL
-# include <dl-vdso.h>
+#endif
-# include <sysdep-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)
 {
+  if (__glibc_unlikely (tz != 0))
+    memset (tz, 0, sizeof *tz);
+
   return INLINE_VSYSCALL (gettimeofday, 2, tv, tz);
 }
 
+#ifdef SHARED
+# include <dl-vdso.h>
+# include <sysdep-vdso.h>
+
 # define INIT_ARCH()
-libc_ifunc_hidden (__gettimeofday, __gettimeofday,
+libc_ifunc (__gettimeofday,
-		   (get_vdso_symbol (HAVE_GETTIMEOFDAY_VSYSCALL)
+	    (get_vdso_symbol (HAVE_GETTIMEOFDAY_VSYSCALL)
-		    ?: __gettimeofday_vsyscall))
+	    ?: __gettimeofday_vsyscall))
-libc_hidden_def (__gettimeofday)
 
 #else
-
-# include <sysdep.h>
 int
 __gettimeofday (struct timeval *tv, struct timezone *tz)
 {
-  return INLINE_SYSCALL (gettimeofday, 2, tv, tz);
+  return __gettimeofday_vsyscall (tv, tz);
 }
-libc_hidden_def (__gettimeofday)
-
 #endif
-
 weak_alias (__gettimeofday, gettimeofday)
-libc_hidden_weak (gettimeofday)

sysdeps/unix/sysv/linux/alpha/gettimeofday.c

@@ -1,5 +1,5 @@
-/* gettimeofday - get the time.  Linux/i386 version.
+/* gettimeofday -- Get the current time of day.  Linux/Alpha/tv64 version.
-   Copyright (C) 2015-2019 Free Software Foundation, Inc.
+   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
    <https://www.gnu.org/licenses/>.  */
 
-#ifdef SHARED
+/* We can use the generic implementation, but we have to override its
-# define __gettimeofday __redirect___gettimeofday
+   default symbol version.  */
-#endif
+#define VERSION_gettimeofday GLIBC_2.1
-
+#include <time/gettimeofday.c>
-#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>

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;
+  if (__glibc_unlikely (tz != 0))
-  __gettimeofday (&tv, tz);
+    memset (tz, 0, sizeof (struct timezone));
 
-  *tv32 = valid_timeval64_to_timeval (tv);
+  struct timespec ts;
+  __clock_gettime (CLOCK_REALTIME, &ts);
+
+  *tv32 = valid_timespec_to_timeval32 (ts);
   return 0;
 }
 

sysdeps/unix/sysv/linux/alpha/tv32-compat.h

@@ -89,6 +89,12 @@ valid_timeval32_to_timespec (const struct timeval32 tv)
   return (struct timespec) { tv.tv_sec, tv.tv_usec * 1000 };
 }
 
+static inline struct timeval32
+valid_timespec_to_timeval32 (const struct timespec ts)
+{
+  return (struct timeval32) { (time_t) ts.tv_sec, ts.tv_nsec / 1000 };
+}
+
 static inline void
 rusage64_to_rusage32 (struct rusage32 *restrict r32,
                       const struct rusage *restrict r64)

sysdeps/unix/sysv/linux/gettimeofday.c

@@ -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
-   <https://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

sysdeps/unix/sysv/linux/powerpc/gettimeofday.c

@@ -15,71 +15,40 @@
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
-#if defined SHARED && !defined __powerpc64__
+#include <time.h>
-# define __gettimeofday __redirect___gettimeofday
+#include <sysdep.h>
-#else
+
-# define __redirect___gettimeofday __gettimeofday
+#ifdef HAVE_GETTIMEOFDAY_VSYSCALL
+# define HAVE_VSYSCALL
 #endif
-
+#include <sysdep-vdso.h>
-#include <sys/time.h>
-
-#ifdef SHARED
-
-# include <dl-vdso.h>
-# include <libc-vdso.h>
-# include <dl-machine.h>
-# include <sysdep.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);
+  if (__glibc_unlikely (tz != 0))
+    memset (tz, 0, sizeof *tz);
+
+  return INLINE_VSYSCALL (gettimeofday, 2, tv, tz);
 }
 
+#ifdef SHARED
+# include <dl-vdso.h>
+# include <libc-vdso.h>
+
 # define INIT_ARCH() \
   void *vdso_gettimeofday = get_vdso_symbol (HAVE_GETTIMEOFDAY_VSYSCALL)
 
 /* If the vDSO is not available we fall back syscall.  */
-libc_ifunc_hidden (__redirect___gettimeofday, __gettimeofday,
+libc_ifunc (__gettimeofday,
-		   vdso_gettimeofday
+	    vdso_gettimeofday
-		   ? VDSO_IFUNC_RET (vdso_gettimeofday)
+	    ? VDSO_IFUNC_RET (vdso_gettimeofday)
-		   : (void *) __gettimeofday_syscall);
+	    : (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);
+  return __gettimeofday_syscall (tv, tz);
 }
-libc_hidden_def (__gettimeofday)
-
 #endif
 weak_alias (__gettimeofday, gettimeofday)
-libc_hidden_weak (gettimeofday)

sysdeps/unix/sysv/linux/x86/gettimeofday.c

@@ -16,47 +16,38 @@
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
-#include <sys/time.h>
+#include <time.h>
+#include <sysdep.h>
 
-#ifdef SHARED
+#ifdef HAVE_GETTIMEOFDAY_VSYSCALL
-
+# define HAVE_VSYSCALL
-# include <dl-vdso.h>
+#endif
-# include <errno.h>
+#include <sysdep-vdso.h>
-# include <sysdep-vdso.h>
-# include <sysdep-vdso.h>
 
 static int
 __gettimeofday_syscall (struct timeval *tv, struct timezone *tz)
 {
-  return INLINE_SYSCALL (gettimeofday, 2, tv, tz);
+  if (__glibc_unlikely (tz != 0))
+    memset (tz, 0, sizeof *tz);
+
+  return INLINE_VSYSCALL (gettimeofday, 2, tv, tz);
 }
 
-# ifndef __gettimeofday_type
+#ifdef SHARED
-/* The i386 gettimeofday.c includes this file with a defined
+# include <dl-vdso.h>
-   __gettimeofday_type macro.  For x86_64 we have to define it to __gettimeofday
+# include <libc-vdso.h>
-   as the internal symbol is the ifunc'ed one.  */
-#  define __gettimeofday_type __gettimeofday
-# endif
 
 # define INIT_ARCH()
 /* If the vDSO is not available we fall back to syscall.  */
-libc_ifunc_hidden (__gettimeofday_type, __gettimeofday,
+libc_ifunc (__gettimeofday,
-		   (get_vdso_symbol ("__vdso_gettimeofday")
+	    (get_vdso_symbol (HAVE_GETTIMEOFDAY_VSYSCALL)
-		    ?: __gettimeofday_syscall));
+	    ?: __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);
+  return __gettimeofday_syscall (tv, tz);
 }
-libc_hidden_def (__gettimeofday)
-
 #endif
 weak_alias (__gettimeofday, gettimeofday)
-libc_hidden_weak (gettimeofday)

sysdeps/unix/sysv/linux/x86_64/x32/gettimeofday.c

@@ -0,0 +1 @@
+#include <sysdeps/unix/sysv/linux/x86/gettimeofday.c>

sysdeps/unix/sysv/linux/x86_64/x32/syscalls.list

@@ -1,6 +1,5 @@
 # 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
 time		-	time:__vdso_time@LINUX_2.6			Ei:P	time

time/gettimeofday.c

@@ -15,20 +15,32 @@
    License along with the GNU C Library; if not, see
    <https://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,
+/* Get the current time of day, putting it into *TV.
-   putting it into *TV and *TZ.  If TZ is NULL, *TZ is not filled.
+   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);
+  if (__glibc_unlikely (tz != 0))
-  return -1;
+    memset (tz, 0, sizeof *tz);
-}
-libc_hidden_def (__gettimeofday)
-weak_alias (__gettimeofday, gettimeofday)
-libc_hidden_weak (gettimeofday)
 
-stub_warning (gettimeofday)
+  struct timespec ts;
+  if (__clock_gettime (CLOCK_REALTIME, &ts))
+    return -1;
+
+  TIMESPEC_TO_TIMEVAL (tv, &ts);
+  return 0;
+}
+
+#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