mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-02 01:40:07 +00:00
1bdda52fe9
This patch moves the vDSO setup from libc to loader code, just after the vDSO link_map setup. For static case the initialization is moved to _dl_non_dynamic_init instead. Instead of using the mangled pointer, the vDSO data is set as attribute_relro (on _rtld_global_ro for shared or _dl_vdso_* for static). It is read-only even with partial relro. It fixes BZ#24967 now that the vDSO pointer is setup earlier than malloc interposition is called. Also, vDSO calls should not be a problem for static dlopen as indicated by BZ#20802. The vDSO pointer would be zero-initialized and the syscall will be issued instead. Checked on x86_64-linux-gnu, i686-linux-gnu, aarch64-linux-gnu, arm-linux-gnueabihf, powerpc64le-linux-gnu, powerpc64-linux-gnu, powerpc-linux-gnu, s390x-linux-gnu, sparc64-linux-gnu, and sparcv9-linux-gnu. I also run some tests on mips. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
59 lines
1.8 KiB
C
59 lines
1.8 KiB
C
/* 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>
|
|
# include <libc-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 = dl_vdso_vsym (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
|