From 83e7640f6bf68708ecf0b09d83c670203167271e Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Fri, 3 May 2013 15:00:31 -0500 Subject: PowerPC: Add time vDSO support PowerPC kernel now provides a vDSO implementation for time syscall (commit fcb41a2030abe0eb716ef0798035ef9562097f42). This patch changes time syscall wrapper to use the vDSO when available. It also changes the default non vDSO time on PowerPC to use sysdeps/posix/time.c (since gettimeofday is a vDSO call). --- sysdeps/unix/sysv/linux/powerpc/Versions | 1 + sysdeps/unix/sysv/linux/powerpc/bits/libc-vdso.h | 6 ++- sysdeps/unix/sysv/linux/powerpc/init-first.c | 4 +- sysdeps/unix/sysv/linux/powerpc/time.c | 62 ++++++++++++++++++++++++ 4 files changed, 70 insertions(+), 3 deletions(-) create mode 100644 sysdeps/unix/sysv/linux/powerpc/time.c (limited to 'sysdeps/unix') diff --git a/sysdeps/unix/sysv/linux/powerpc/Versions b/sysdeps/unix/sysv/linux/powerpc/Versions index 396a4236c1..289c4fe9b7 100644 --- a/sysdeps/unix/sysv/linux/powerpc/Versions +++ b/sysdeps/unix/sysv/linux/powerpc/Versions @@ -4,5 +4,6 @@ libc { __vdso_clock_gettime; __vdso_clock_getres; __vdso_getcpu; + __vdso_time; } } diff --git a/sysdeps/unix/sysv/linux/powerpc/bits/libc-vdso.h b/sysdeps/unix/sysv/linux/powerpc/bits/libc-vdso.h index 5f5fc1eb3a..8b195db1bf 100644 --- a/sysdeps/unix/sysv/linux/powerpc/bits/libc-vdso.h +++ b/sysdeps/unix/sysv/linux/powerpc/bits/libc-vdso.h @@ -32,14 +32,16 @@ extern void *__vdso_get_tbfreq; extern void *__vdso_getcpu; +extern void *__vdso_time; + /* This macro is needed for PPC64 to return a skeleton OPD entry of a vDSO symbol. This works because _dl_vdso_vsym always return the function address, and no vDSO symbols use the TOC or chain pointers from the OPD so we can allow them to be garbage. */ #if defined(__PPC64__) || defined(__powerpc64__) -#define VDSO_IFUNC_RET(value) &value +#define VDSO_IFUNC_RET(value) ((void *) &(value)) #else -#define VDSO_IFUNC_RET(value) value +#define VDSO_IFUNC_RET(value) ((void *) (value)) #endif #endif diff --git a/sysdeps/unix/sysv/linux/powerpc/init-first.c b/sysdeps/unix/sysv/linux/powerpc/init-first.c index 204c0c60a4..f6f05f0ba2 100644 --- a/sysdeps/unix/sysv/linux/powerpc/init-first.c +++ b/sysdeps/unix/sysv/linux/powerpc/init-first.c @@ -28,7 +28,7 @@ void *__vdso_clock_gettime; void *__vdso_clock_getres; void *__vdso_get_tbfreq; void *__vdso_getcpu; - +void *__vdso_time; static inline void _libc_vdso_platform_setup (void) @@ -44,6 +44,8 @@ _libc_vdso_platform_setup (void) __vdso_get_tbfreq = _dl_vdso_vsym ("__kernel_get_tbfreq", &linux2615); __vdso_getcpu = _dl_vdso_vsym ("__kernel_getcpu", &linux2615); + + __vdso_time = _dl_vdso_vsym ("__kernel_time", &linux2615); } # define VDSO_SETUP _libc_vdso_platform_setup diff --git a/sysdeps/unix/sysv/linux/powerpc/time.c b/sysdeps/unix/sysv/linux/powerpc/time.c new file mode 100644 index 0000000000..66b4eb3049 --- /dev/null +++ b/sysdeps/unix/sysv/linux/powerpc/time.c @@ -0,0 +1,62 @@ +/* time system call for Linux/PowerPC. + Copyright (C) 2013 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 + . */ + +#ifdef SHARED + +# include +# include +# include + +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) +{ + /* If the vDSO is not available we fall back to the syscall. */ + return (__vdso_time ? VDSO_IFUNC_RET (__vdso_time) + : 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\n" + "__GI_time = time"); + +#else + +#include + +#endif -- cgit 1.4.1