summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorAndi Kleen <ak@suse.de>2007-09-11 14:02:09 +0200
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-09-12 18:28:06 +0200
commit95b08679963c78ce0d675224a6efdb5169f2bf75 (patch)
tree2b242803ab4f54333f874ffcf237fc9c7427a0a7
parentMerge branch 'for-linus' of git://git.o-hand.com/linux-rpurdie-leds (diff)
downloadlinux-95b08679963c78ce0d675224a6efdb5169f2bf75.tar.xz
linux-95b08679963c78ce0d675224a6efdb5169f2bf75.zip
x86_64: Add missing mask operation to vdso
vdso vgetns() didn't mask the time source offset calculation, which could lead to time problems with 32bit HPET. Add the masking. Thanks to Chuck Ebbert for tracking this down. Signed-off-by: Andi Kleen <ak@suse.de> Cc: Chuck Ebbert <cebbert@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--arch/x86_64/vdso/vclock_gettime.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/x86_64/vdso/vclock_gettime.c b/arch/x86_64/vdso/vclock_gettime.c
index 17f6a00de712..5b54cdfb2b07 100644
--- a/arch/x86_64/vdso/vclock_gettime.c
+++ b/arch/x86_64/vdso/vclock_gettime.c
@@ -34,10 +34,11 @@ static long vdso_fallback_gettime(long clock, struct timespec *ts)
static inline long vgetns(void)
{
+ long v;
cycles_t (*vread)(void);
vread = gtod->clock.vread;
- return ((vread() - gtod->clock.cycle_last) * gtod->clock.mult) >>
- gtod->clock.shift;
+ v = (vread() - gtod->clock.cycle_last) & gtod->clock.mask;
+ return (v * gtod->clock.mult) >> gtod->clock.shift;
}
static noinline int do_realtime(struct timespec *ts)