diff options
| author | Lin Ming <ming.m.lin@intel.com> | 2009-11-17 13:49:50 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-08-13 13:20:13 -0700 |
| commit | 8aa3149405e33cec4f866cfe7f92c2b40d259613 (patch) | |
| tree | 09f97167f628a98a2606cf0a7ff669797379c7de /arch/powerpc | |
| parent | e66bb883118bf9db3b66f2ec3315be83d2b27aeb (diff) | |
timekeeping: Fix clock_gettime vsyscall time warp
commit 0696b711e4be45fa104c12329f617beb29c03f78 upstream.
Since commit 0a544198 "timekeeping: Move NTP adjusted clock multiplier
to struct timekeeper" the clock multiplier of vsyscall is updated with
the unmodified clock multiplier of the clock source and not with the
NTP adjusted multiplier of the timekeeper.
This causes user space observerable time warps:
new CLOCK-warp maximum: 120 nsecs, 00000025c337c537 -> 00000025c337c4bf
Add a new argument "mult" to update_vsyscall() and hand in the
timekeeping internal NTP adjusted multiplier.
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Cc: "Zhang Yanmin" <yanmin_zhang@linux.intel.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Tony Luck <tony.luck@intel.com>
LKML-Reference: <1258436990.17765.83.camel@minggr.sh.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Kurt Garloff <garloff@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'arch/powerpc')
| -rw-r--r-- | arch/powerpc/kernel/time.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c index 02aab7f90295..7143d4ce1cd8 100644 --- a/arch/powerpc/kernel/time.c +++ b/arch/powerpc/kernel/time.c @@ -864,7 +864,8 @@ static cycle_t timebase_read(struct clocksource *cs) return (cycle_t)get_tb(); } -void update_vsyscall(struct timespec *wall_time, struct clocksource *clock) +void update_vsyscall(struct timespec *wall_time, struct clocksource *clock, + u32 mult) { u64 t2x, stamp_xsec; @@ -877,7 +878,7 @@ void update_vsyscall(struct timespec *wall_time, struct clocksource *clock) /* XXX this assumes clock->shift == 22 */ /* 4611686018 ~= 2^(20+64-22) / 1e9 */ - t2x = (u64) clock->mult * 4611686018ULL; + t2x = (u64) mult * 4611686018ULL; stamp_xsec = (u64) xtime.tv_nsec * XSEC_PER_SEC; do_div(stamp_xsec, 1000000000); stamp_xsec += (u64) xtime.tv_sec * XSEC_PER_SEC; |