Commit 7861144b authored Apr 18, 2014 by Andrew Morton Committed by Linus Torvalds Apr 18, 2014

kernel/watchdog.c:touch_softlockup_watchdog(): use raw_cpu_write()



Fix:

  BUG: using __this_cpu_write() in preemptible [00000000] code: systemd-udevd/497
  caller is __this_cpu_preempt_check+0x13/0x20
  CPU: 3 PID: 497 Comm: systemd-udevd Tainted: G        W     3.15.0-rc1 #9
  Hardware name: Hewlett-Packard HP EliteBook 8470p/179B, BIOS 68ICF Ver. F.02 04/27/2012
  Call Trace:
    check_preemption_disabled+0xe1/0xf0
    __this_cpu_preempt_check+0x13/0x20
    touch_nmi_watchdog+0x28/0x40

Reported-by: Luis Henriques <luis.henriques@canonical.com>
Tested-by: Luis Henriques <luis.henriques@canonical.com>
Cc: Eric Piel <eric.piel@tremplin-utc.net>
Cc: Robert Moore <robert.moore@intel.com>
Cc: Lv Zheng <lv.zheng@intel.com>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 82c04ff8

kernel/watchdog.c

+5 −1

Original line number	Diff line number	Diff line
		@@ -138,7 +138,11 @@ static void __touch_watchdog(void)

		void touch_softlockup_watchdog(void)
		{
		__this_cpu_write(watchdog_touch_ts, 0);
		/*
		* Preemption can be enabled. It doesn't matter which CPU's timestamp
		* gets zeroed here, so use the raw_ operation.
		*/
		raw_cpu_write(watchdog_touch_ts, 0);
		}
		EXPORT_SYMBOL(touch_softlockup_watchdog);

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