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[PATCH] fix vsyscall settimeofday

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To: <akpm@...>
Cc: <linux-kernel@...>, <johnstul@...>
Date: Monday, March 5, 2007 - 12:56 pm

I've only seen this on x86_64 .

The vsyscall state only gets updated when a timer interrupts comes in . So
if the time is set long before the next timer, there will be a period when
a gettimeofday() won't reflect the correct time.

I added an explicit update_vsyscall() during the settimeofday(), that way
the vsyscall state doesn't get stale.

Any thought John?

Signed-Off-By: Daniel Walker <dwalker@mvista.com>

---
 kernel/timer.c |    2 ++
 1 file changed, 2 insertions(+)

Index: linux-2.6.20/kernel/timer.c
===================================================================
--- linux-2.6.20.orig/kernel/timer.c
+++ linux-2.6.20/kernel/timer.c
@@ -861,6 +861,8 @@ int do_settimeofday(struct timespec *tv)
 	clock->error = 0;
 	ntp_clear();
 
+	update_vsyscall(&xtime, clock);
+
 	write_sequnlock_irqrestore(&xtime_lock, flags);
 
 	/* signal hrtimers about time change */
-- 
-
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Messages in current thread:
[PATCH] fix vsyscall settimeofday, Daniel Walker, (Mon Mar 5, 12:56 pm)
Re: [PATCH] fix vsyscall settimeofday, john stultz, (Mon Mar 5, 2:57 pm)
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