linux: Consolidate Linux gettimeofday

The IFUNC bypass to vDSO is used when USE_IFUNC_GETTIMEOFDAY is set.
Currently aarch64, powerpc*, and x86 defines it.  Otherwise the
generic implementation is used, which calls clock_gettime.

Checked on aarch64-linux-gnu, powerpc64le-linux-gnu,
powerpc64-linux-gnu, powerpc-linux-gnu-power4, x86_64-linux-gnu,
and i686-linux-gnu.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
This commit is contained in:
Adhemerval Zanella 2019-12-16 09:45:55 -03:00
parent 7bcaf77574
commit c701bcc6f4
4 changed files with 63 additions and 100 deletions

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@ -16,39 +16,5 @@
License along with the GNU C Library; if not, see
<https://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. */
#include <time.h>
#include <sysdep.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 *restrict tv, void *restrict 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 (__gettimeofday,
(get_vdso_symbol (HAVE_GETTIMEOFDAY_VSYSCALL)
?: __gettimeofday_vsyscall))
#else
int
__gettimeofday (struct timeval *restrict tv, void *restrict tz)
{
return __gettimeofday_vsyscall (tv, tz);
}
#endif
weak_alias (__gettimeofday, gettimeofday)
#define USE_IFUNC_GETTIMEOFDAY
#include <sysdeps/unix/sysv/linux/gettimeofday.c>

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@ -0,0 +1,57 @@
/* gettimeofday - set time. Linux version.
Copyright (C) 2020 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/>. */
/* Optimize the function call by setting the PLT directly to vDSO symbol. */
#ifdef USE_IFUNC_GETTIMEOFDAY
# include <time.h>
# include <string.h>
# include <sysdep.h>
# include <sysdep-vdso.h>
# ifdef SHARED
# include <dl-vdso.h>
static int
__gettimeofday_syscall (struct timeval *restrict tv, void *restrict tz)
{
if (__glibc_unlikely (tz != 0))
memset (tz, 0, sizeof *tz);
return INLINE_SYSCALL_CALL (gettimeofday, tv, tz);
}
# undef INIT_ARCH
# define INIT_ARCH() \
void *vdso_gettimeofday = get_vdso_symbol (HAVE_GETTIMEOFDAY_VSYSCALL)
libc_ifunc (__gettimeofday,
vdso_gettimeofday ? VDSO_IFUNC_RET (vdso_gettimeofday)
: (void *) __gettimeofday_syscall)
# else
int
__gettimeofday (struct timeval *restrict tv, void *restrict tz)
{
if (__glibc_unlikely (tz != 0))
memset (tz, 0, sizeof *tz);
return INLINE_VSYSCALL (gettimeofday, 2, tv, tz);
}
# endif
weak_alias (__gettimeofday, gettimeofday)
#else /* USE_IFUNC_GETTIMEOFDAY */
# include <time/gettimeofday.c>
#endif

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@ -15,36 +15,5 @@
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <time.h>
#include <sysdep.h>
#include <sysdep-vdso.h>
static int
__gettimeofday_syscall (struct timeval *restrict tv, void *restrict 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 (__gettimeofday,
vdso_gettimeofday
? VDSO_IFUNC_RET (vdso_gettimeofday)
: (void *) __gettimeofday_syscall);
#else
int
__gettimeofday (struct timeval *restrict tv, void *restrict tz)
{
return __gettimeofday_syscall (tv, tz);
}
#endif
weak_alias (__gettimeofday, gettimeofday)
#define USE_IFUNC_GETTIMEOFDAY
#include <sysdeps/unix/sysv/linux/gettimeofday.c>

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@ -16,34 +16,5 @@
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <time.h>
#include <sysdep.h>
#include <sysdep-vdso.h>
static int
__gettimeofday_syscall (struct timeval *restrict tv, void *restrict 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()
/* If the vDSO is not available we fall back to syscall. */
libc_ifunc (__gettimeofday,
(get_vdso_symbol (HAVE_GETTIMEOFDAY_VSYSCALL)
?: __gettimeofday_syscall));
#else
int
__gettimeofday (struct timeval *restrict tv, void *restrict tz)
{
return __gettimeofday_syscall (tv, tz);
}
#endif
weak_alias (__gettimeofday, gettimeofday)
#define USE_IFUNC_GETTIMEOFDAY
#include <sysdeps/unix/sysv/linux/gettimeofday.c>