mirrors/glibc
1
0
Fork 0
mirror of https://sourceware.org/git/glibc.git synced 2024-11-30 21:23:52 +08:00
Code Issues Actions Packages Projects Releases Wiki Activity

Prefer real syscalls instead of vsyscalls on x86-64 outside libc.so

Browse Source
This commit is contained in:
Ulrich Drepper 2011-09-06 00:12:18 -04:00
parent 6585cb60ee
commit ef60624956
5 changed files with 40 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
ChangeLog
View File

@ -1,3 +1,13 @@
2011-09-06 Ulrich Drepper <drepper@gmail.com>
* sysdeps/unix/sysv/linux/kernel-features.h: Add entry for getcpu
syscall on x86-64.
* sysdeps/unix/sysv/linux/x86_64/gettimeofday.c [!SHARED]: Use real
syscall.
* sysdeps/unix/sysv/linux/x86_64/time.c: Likewise.
* sysdeps/unix/sysv/linux/x86_64/sched_getcpu.S [!SHARED]: Use real
syscall if possible.
2011-09-05 Ulrich Drepper <drepper@gmail.com>
* elf/pldd.c (get_process_info): Don't read whole ELF header, just

5
sysdeps/unix/sysv/linux/kernel-features.h
View File

@ -546,3 +546,8 @@
#if __LINUX_KERNEL_VERSION >= 0x020627
# define __ASSUME_SENDMMSG 1
#endif
/* getcpu is a syscall for x86-64 since 3.1. */
#if defined __x86_64__ && __LINUX_KERNEL_VERSION >= 0x030100
# define __ASSUME_GETCPU_SYSCALL 1
#endif

3
sysdeps/unix/sysv/linux/x86_64/gettimeofday.c
View File

@ -37,11 +37,12 @@ gettimeofday_ifunc (void)
__asm (".type __gettimeofday, %gnu_indirect_function");
#else
# include <sys/time.h>
# include <sysdep.h>
int
__gettimeofday (struct timeval *tv, struct timezone *tz)
{
return ((int (*) (struct timeval *, struct timezone *)) VSYSCALL_ADDR_vgettimeofday) (tv, tz);
return INLINE_SYSCALL (gettimeofday, 2, tv, tz);
}
#endif

23
sysdeps/unix/sysv/linux/x86_64/sched_getcpu.S
View File

@ -20,6 +20,7 @@
#include <tls.h>
#define _ERRNO_H 1
#include <bits/errno.h>
#include <kernel-features.h>
/* For the calculation see asm/vsyscall.h. */
#define VSYSCALL_ADDR_vgetcpu 0xffffffffff600800
@ -38,10 +39,26 @@ ENTRY (sched_getcpu)
#ifdef SHARED
movq __vdso_getcpu(%rip), %rax
PTR_DEMANGLE (%rax)
#else
movq $VSYSCALL_ADDR_vgetcpu, %rax
#endif
callq *%rax
#else
# ifdef __NR_getcpu
movl $__NR_getcpu, %eax
syscall
# ifndef __ASSUME_GETCPU_SYSCALL
cmpq $-ENOSYS, %rax
jne 1f
# endif
# endif
# ifndef __ASSUME_GETCPU_SYSCALL
movq $VSYSCALL_ADDR_vgetcpu, %rax
callq *%rax
1:
# else
# ifndef __NR_getcpu
# error "cannot happen"
# endif
# endif
#endif
cmpq $-4095, %rax
jae SYSCALL_ERROR_LABEL

4
sysdeps/unix/sysv/linux/x86_64/time.c
View File

@ -36,11 +36,13 @@ time_ifunc (void)
__asm (".type time, %gnu_indirect_function");
#else
# include <time.h>
# include <sysdep.h>
time_t
time (time_t *t)
{
return ((time_t (*) (time_t *)) VSYSCALL_ADDR_vtime) (t);
INTERNAL_SYSCALL_DECL (err);
return INTERNAL_SYSCALL (time, err, 1, t);
}
#endif