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| author | Eric Dumazet <dada1@cosmosbay.com> | 2007-05-02 19:27:11 +0200 |
|---|---|---|
| committer | Andi Kleen <andi@basil.nowhere.org> | 2007-05-02 19:27:11 +0200 |
| commit | 272a3713bb9e302e0455c894c41180a482d2c8a3 (patch) | |
| tree | 2dad036c75c0523db5f5f0f9618f4f3b9f21e28c | |
| parent | bd8559c38ee5be40ce2c57a80fd3c3e978cca267 (diff) | |
| download | op-kernel-dev-272a3713bb9e302e0455c894c41180a482d2c8a3.zip op-kernel-dev-272a3713bb9e302e0455c894c41180a482d2c8a3.tar.gz | |
[PATCH] x86-64: fix vtime() vsyscall
There is a tiny probability that the return value from vtime(time_t *t) is
Signed-off-by: Andi Kleen <ak@suse.de>
different than the value stored in *t
Using a temporary variable solves the problem and gives a faster code.
17: 48 85 ff test %rdi,%rdi
1a: 48 8b 05 00 00 00 00 mov 0(%rip),%rax #
__vsyscall_gtod_data.wall_time_tv.tv_sec
21: 74 03 je 26
23: 48 89 07 mov %rax,(%rdi)
26: c9 leaveq
27: c3 retq
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
| -rw-r--r-- | arch/x86_64/kernel/vsyscall.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/arch/x86_64/kernel/vsyscall.c b/arch/x86_64/kernel/vsyscall.c index d14cbb3..ba330f8 100644 --- a/arch/x86_64/kernel/vsyscall.c +++ b/arch/x86_64/kernel/vsyscall.c @@ -156,11 +156,13 @@ int __vsyscall(0) vgettimeofday(struct timeval * tv, struct timezone * tz) * unlikely */ time_t __vsyscall(1) vtime(time_t *t) { + time_t result; if (unlikely(!__vsyscall_gtod_data.sysctl_enabled)) return time_syscall(t); - else if (t) - *t = __vsyscall_gtod_data.wall_time_tv.tv_sec; - return __vsyscall_gtod_data.wall_time_tv.tv_sec; + result = __vsyscall_gtod_data.wall_time_tv.tv_sec; + if (t) + *t = result; + return result; } /* Fast way to get current CPU and node. |
