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d98720e07f
The IFUNC selector for gettimeofday runs before _libc_vdso_platform_setup where __vdso_gettimeofday is set. The selector then sets __gettimeofday (the internal version used within GLIBC) to use the system call version instead of the vDSO one. This patch changes the check if vDSO is available to get its value directly instead of rely on __vdso_gettimeofday. This patch changes it by getting the vDSO value directly. It fixes BZ#16431.
84 lines
2.3 KiB
C
84 lines
2.3 KiB
C
/* time system call for Linux/PowerPC.
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Copyright (C) 2013-2014 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#ifdef SHARED
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# include <time.h>
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# include <sysdep.h>
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# include <dl-vdso.h>
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# include <bits/libc-vdso.h>
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# include <dl-machine.h>
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void *time_ifunc (void) asm ("time");
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static time_t
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time_syscall (time_t *t)
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{
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struct timeval tv;
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time_t result;
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if (INLINE_VSYSCALL (gettimeofday, 2, &tv, NULL) < 0)
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result = (time_t) -1;
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else
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result = (time_t) tv.tv_sec;
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if (t != NULL)
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*t = result;
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return result;
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}
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void *
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time_ifunc (void)
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{
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PREPARE_VERSION (linux2615, "LINUX_2.6.15", 123718565);
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/* If the vDSO is not available we fall back to the syscall. */
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void *vdso_time = _dl_vdso_vsym ("__kernel_time", &linux2615);
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return (vdso_time ? VDSO_IFUNC_RET (vdso_time)
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: (void*)time_syscall);
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}
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asm (".type time, %gnu_indirect_function");
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/* This is doing "libc_hidden_def (time)" but the compiler won't
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* let us do it in C because it doesn't know we're defining time
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* here in this file. */
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asm (".globl __GI_time");
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/* __GI_time is defined as hidden and for ppc32 it enables the
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compiler make a local call (symbol@local) for internal GLIBC usage. It
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means the PLT won't be used and the ifunc resolver will be called directly.
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For ppc64 a call to a function in another translation unit might use a
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different toc pointer thus disallowing direct branchess and making internal
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ifuncs calls safe. */
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#ifdef __powerpc64__
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asm ("__GI_time = time");
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#else
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time_t
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__time_vsyscall (time_t *t)
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{
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return INLINE_VSYSCALL (time, 1, t);
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}
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asm ("__GI_time = __time_vsyscall");
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#endif
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#else
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#include <sysdeps/posix/time.c>
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#endif
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