This is a note to let you know that I've just added the patch titled
timekeeping: Fix lost updates to tai adjustment
to the 3.12-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
timekeeping-fix-lost-updates-to-tai-adjustment.patch
and it can be found in the queue-3.12 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From f55c07607a38f84b5c7e6066ee1cfe433fa5643c Mon Sep 17 00:00:00 2001
From: John Stultz <john.stultz@xxxxxxxxxx>
Date: Wed, 11 Dec 2013 18:50:25 -0800
Subject: timekeeping: Fix lost updates to tai adjustment
From: John Stultz <john.stultz@xxxxxxxxxx>
commit f55c07607a38f84b5c7e6066ee1cfe433fa5643c upstream.
Since 48cdc135d4840 (Implement a shadow timekeeper), we have to
call timekeeping_update() after any adjustment to the timekeeping
structure in order to make sure that any adjustments to the structure
persist.
Unfortunately, the updates to the tai offset via adjtimex do not
trigger this update, causing adjustments to the tai offset to be
made and then over-written by the previous value at the next
update_wall_time() call.
This patch resovles the issue by calling timekeeping_update()
right after setting the tai offset.
Cc: Sasha Levin <sasha.levin@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Prarit Bhargava <prarit@xxxxxxxxxx>
Cc: Richard Cochran <richardcochran@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: John Stultz <john.stultz@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
kernel/time/timekeeping.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -610,6 +610,7 @@ void timekeeping_set_tai_offset(s32 tai_
raw_spin_lock_irqsave(&timekeeper_lock, flags);
write_seqcount_begin(&timekeeper_seq);
__timekeeping_set_tai_offset(tk, tai_offset);
+ timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET);
write_seqcount_end(&timekeeper_seq);
raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
clock_was_set();
@@ -1697,7 +1698,7 @@ int do_adjtimex(struct timex *txc)
if (tai != orig_tai) {
__timekeeping_set_tai_offset(tk, tai);
- update_pvclock_gtod(tk, true);
+ timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET);
clock_was_set_delayed();
}
write_seqcount_end(&timekeeper_seq);
Patches currently in stable-queue which might be from john.stultz@xxxxxxxxxx are
queue-3.12/timekeeping-fix-potential-lost-pv-notification-of-time-change.patch
queue-3.12/timekeeping-fix-lost-updates-to-tai-adjustment.patch
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