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/* time system call for Linux/PowerPC.
Copyright (C) 2013-2016 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 <time.h>
# include <sysdep.h>
# include <dl-vdso.h>
# include <libc-vdso.h>
# include <dl-machine.h>
void *time_ifunc (void) asm ("time");
static time_t
time_syscall (time_t *t)
{
struct timeval tv;
time_t result;
if (INLINE_VSYSCALL (gettimeofday, 2, &tv, NULL) < 0)
result = (time_t) -1;
else
result = (time_t) tv.tv_sec;
if (t != NULL)
*t = result;
return result;
}
void *
time_ifunc (void)
{
PREPARE_VERSION (linux2615, "LINUX_2.6.15", 123718565);
/* If the vDSO is not available we fall back to the syscall. */
void *vdso_time = _dl_vdso_vsym ("__kernel_time", &linux2615);
return (vdso_time ? VDSO_IFUNC_RET (vdso_time)
: (void*)time_syscall);
}
asm (".type time, %gnu_indirect_function");
/* This is doing "libc_hidden_def (time)" but the compiler won't
* let us do it in C because it doesn't know we're defining time
* here in this file. */
asm (".globl __GI_time");
/* __GI_time 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. */
#ifdef __powerpc64__
asm ("__GI_time = time");
#else
time_t
__time_vsyscall (time_t *t)
{
return INLINE_VSYSCALL (time, 1, t);
}
asm ("__GI_time = __time_vsyscall");
#endif
#else
#include <sysdeps/posix/time.c>
#endif
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