From 1001d0a9ee74a468077dfd4da0565174e88de26b Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Fri, 1 Feb 2008 17:45:13 +0100
Subject: [PATCH] timekeeping: update xtime_cache when time(zone) changes
xtime_cache needs to be updated whenever xtime and or wall_to_monotic
are changed. Otherwise users of xtime_cache might see a stale (and in
the case of timezone changes utterly wrong) value until the next
update happens.
Fixup the obvious places, which miss this update.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <johnstul@us.ibm.com>
Tested-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
include/linux/time.h | 1 +
kernel/time.c | 1 +
kernel/time/timekeeping.c | 6 ++++--
3 files changed, 6 insertions(+), 2 deletions(-)
diff --git a/include/linux/time.h b/include/linux/time.h
index b04136d60a2f..ceaab9fff155 100644
--- a/include/linux/time.h
+++ b/include/linux/time.h
@@ -122,6 +122,7 @@ extern void monotonic_to_bootbased(struct timespec *ts);
extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
extern int timekeeping_is_continuous(void);
extern void update_wall_time(void);
+extern void update_xtime_cache(u64 nsec);
/**
* timespec_to_ns - Convert timespec to nanoseconds
diff --git a/kernel/time.c b/kernel/time.c
index 09d3c45c4da7..4064c0566e77 100644
--- a/kernel/time.c
+++ b/kernel/time.c
@@ -129,6 +129,7 @@ static inline void warp_clock(void)
write_seqlock_irq(&xtime_lock);
wall_to_monotonic.tv_sec -= sys_tz.tz_minuteswest * 60;
xtime.tv_sec += sys_tz.tz_minuteswest * 60;
+ update_xtime_cache(0);
write_sequnlock_irq(&xtime_lock);
clock_was_set();
}
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 092a2366b5a9..cd5dbc4579c9 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -47,7 +47,7 @@ struct timespec wall_to_monotonic __attribute__ ((aligned (16)));
static unsigned long total_sleep_time; /* seconds */
static struct timespec xtime_cache __attribute__ ((aligned (16)));
-static inline void update_xtime_cache(u64 nsec)
+void update_xtime_cache(u64 nsec)
{
xtime_cache = xtime;
timespec_add_ns(&xtime_cache, nsec);
@@ -145,6 +145,7 @@ int do_settimeofday(struct timespec *tv)
set_normalized_timespec(&xtime, sec, nsec);
set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
+ update_xtime_cache(0);
clock->error = 0;
ntp_clear();
@@ -252,8 +253,8 @@ void __init timekeeping_init(void)
xtime.tv_nsec = 0;
set_normalized_timespec(&wall_to_monotonic,
-xtime.tv_sec, -xtime.tv_nsec);
+ update_xtime_cache(0);
total_sleep_time = 0;
-
write_sequnlock_irqrestore(&xtime_lock, flags);
}
@@ -290,6 +291,7 @@ static int timekeeping_resume(struct sys_device *dev)
}
/* Make sure that we have the correct xtime reference */
timespec_add_ns(&xtime, timekeeping_suspend_nsecs);
+ update_xtime_cache(0);
/* re-base the last cycle value */
clock->cycle_last = clocksource_read(clock);
clock->error = 0;
--
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