glibc/sysdeps/unix/sysv/linux/s390/init-first.c
Stefan Liebler b91a333ecb S390: Add support for vdso getcpu symbol.
This patch adds support for symbol __kernel_getcpu in vDSO,
which is available with kernel 4.5.
Now sched_getcpu is using this symbol if available in mapped vDSO
by defining macro HAVE_GETCPU_VSYSCALL. If not available at runtime,
the former syscall is used.
2016-05-09 11:05:45 +02:00

61 lines
1.9 KiB
C

/* Initialization code run first thing by the ELF startup code. Linux/s390.
Copyright (C) 2008-2016 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/>. */
#ifdef SHARED
# 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));
long int (*VDSO_SYMBOL(clock_getres)) (clockid_t, struct timespec *)
__attribute__ ((nocommon));
long int (*VDSO_SYMBOL(getcpu)) (unsigned *, unsigned *, void *)
attribute_hidden;
static inline void
_libc_vdso_platform_setup (void)
{
PREPARE_VERSION (linux2629, "LINUX_2.6.29", 123718585);
void *p = _dl_vdso_vsym ("__kernel_gettimeofday", &linux2629);
PTR_MANGLE (p);
VDSO_SYMBOL (gettimeofday) = p;
p = _dl_vdso_vsym ("__kernel_clock_gettime", &linux2629);
PTR_MANGLE (p);
VDSO_SYMBOL (clock_gettime) = p;
p = _dl_vdso_vsym ("__kernel_clock_getres", &linux2629);
PTR_MANGLE (p);
VDSO_SYMBOL (clock_getres) = p;
p = _dl_vdso_vsym ("__kernel_getcpu", &linux2629);
PTR_MANGLE (p);
VDSO_SYMBOL (getcpu) = p;
}
# define VDSO_SETUP _libc_vdso_platform_setup
#endif
#include <csu/init-first.c>