Patch "clocksource: Fix abs() usage w/ 64bit values" has been added to the 4.2-stable tree

Patch "clocksource: Fix abs() usage w/ 64bit values" has been added to the 4.2-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    clocksource: Fix abs() usage w/ 64bit values

to the 4.2-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:
     clocksource-fix-abs-usage-w-64bit-values.patch
and it can be found in the queue-4.2 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 67dfae0cd72fec5cd158b6e5fb1647b7dbe0834c Mon Sep 17 00:00:00 2001
From: John Stultz <john.stultz@linaro.org>
Date: Mon, 14 Sep 2015 18:05:20 -0700
Subject: clocksource: Fix abs() usage w/ 64bit values

From: John Stultz <john.stultz@linaro.org>

commit 67dfae0cd72fec5cd158b6e5fb1647b7dbe0834c upstream.

This patch fixes one cases where abs() was being used with 64-bit
nanosecond values, where the result may be capped at 32-bits.

This potentially could cause watchdog false negatives on 32-bit
systems, so this patch addresses the issue by using abs64().

Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Link: http://lkml.kernel.org/r/1442279124-7309-2-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 kernel/time/clocksource.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -217,7 +217,7 @@ static void clocksource_watchdog(unsigne
 			continue;
 
 		/* Check the deviation from the watchdog clocksource. */
-		if ((abs(cs_nsec - wd_nsec) > WATCHDOG_THRESHOLD)) {
+		if (abs64(cs_nsec - wd_nsec) > WATCHDOG_THRESHOLD) {
 			pr_warn("timekeeping watchdog: Marking clocksource '%s' as unstable because the skew is too large:\n",
 				cs->name);
 			pr_warn("                      '%s' wd_now: %llx wd_last: %llx mask: %llx\n",


Patches currently in stable-queue which might be from john.stultz@linaro.org are

queue-4.2/time-fix-timekeeping_freqadjust-s-incorrect-use-of-abs-instead-of-abs64.patch
queue-4.2/clocksource-fix-abs-usage-w-64bit-values.patch