| /* time system call for Linux/PowerPC. |
| Copyright (C) 2013-2014 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 <bits/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 |