mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-26 04:31:03 +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>
52 lines
1.5 KiB
C
52 lines
1.5 KiB
C
/* time -- Get number of seconds since Epoch. 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_TIME
|
|
# include <time.h>
|
|
# include <sysdep.h>
|
|
# include <sysdep-vdso.h>
|
|
|
|
#ifdef SHARED
|
|
# include <dl-vdso.h>
|
|
# include <libc-vdso.h>
|
|
|
|
static time_t
|
|
time_syscall (time_t *t)
|
|
{
|
|
return INLINE_SYSCALL_CALL (time, t);
|
|
}
|
|
|
|
# undef INIT_ARCH
|
|
# define INIT_ARCH() \
|
|
void *vdso_time = dl_vdso_vsym (HAVE_TIME_VSYSCALL);
|
|
libc_ifunc (time,
|
|
vdso_time ? VDSO_IFUNC_RET (vdso_time)
|
|
: (void *) time_syscall);
|
|
|
|
# else
|
|
time_t
|
|
time (time_t *t)
|
|
{
|
|
return INLINE_VSYSCALL (time, 1, t);
|
|
}
|
|
# endif /* !SHARED */
|
|
#else /* USE_IFUNC_TIME */
|
|
# include <time/time.c>
|
|
#endif
|