Commit 90675a27 authored Mar 06, 2007 by Daniel Walker Committed by Linus Torvalds Mar 06, 2007

[PATCH] fix vsyscall settimeofday



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.

Signed-off-by: Daniel Walker <dwalker@mvista.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 7a434814

kernel/timer.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -862,6 +862,8 @@ 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 */