From: Michal Hocko <mhocko@suse.cz>
Date: Tue, 24 Sep 2013 22:27:29 +0000 (-0700)
Subject: watchdog: update watchdog attributes atomically
X-Git-Tag: v3.12-rc3~33^2~16
X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=359e6fab6600562073162348cd4c18c5958296d8;p=pandora-kernel.git

watchdog: update watchdog attributes atomically

proc_dowatchdog doesn't synchronize multiple callers which might lead to
confusion when two parallel callers might confuse watchdog_enable_all_cpus
resp watchdog_disable_all_cpus (eg watchdog gets enabled even if
watchdog_thresh was set to 0 already).

This patch adds a local mutex which synchronizes callers to the sysctl
handler.

Signed-off-by: Michal Hocko <mhocko@suse.cz>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Don Zickus <dzickus@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

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