[PATCH RT 07/25][RFC 3.0.23-rt39-rc1] x86: vdso: Remove bogus locking in update_vsyscall_tz()

Steven Rostedt
2012-03-06T16:16:43Z

[-- Attachment #1: 0007-x86-vdso-Remove-bogus-locking-in-update_vsyscall_tz.patch --]
[-- Type: text/plain, Size: 1088 bytes --]

From: Thomas Gleixner <tglx@linutronix.de>

Changing the sequence count in update_vsyscall_tz() is completely
pointless.

The vdso code copies the data unprotected. There is no point to change
this as sys_tz is nowhere protected at all. See sys_gettimeofday().

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable-rt@vger.kernel.org
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
arch/x86/kernel/vsyscall_64.c | 5 -----
1 files changed, 0 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kernel/vsyscall_64.c b/arch/x86/kernel/vsyscall_64.c
index 0a7dc13..c378a18 100644
--- a/arch/x86/kernel/vsyscall_64.c
+++ b/arch/x86/kernel/vsyscall_64.c
@@ -58,12 +58,7 @@ DEFINE_VVAR(struct vsyscall_gtod_data, vsyscall_gtod_data) =

void update_vsyscall_tz(void)
{
- unsigned long flags;
-
- write_seqlock_irqsave(&vsyscall_gtod_data.lock, flags);
- /* sys_tz has changed */
vsyscall_gtod_data.sys_tz = sys_tz;
- write_sequnlock_irqrestore(&vsyscall_gtod_data.lock, flags);
}

void update_vsyscall(struct timespec *wall_time, struct timespec *wtm,
--
1.7.8.3