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 torvalds#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 <[email protected]> Tested-by: Luis Henriques <[email protected]> Cc: Eric Piel <[email protected]> Cc: Robert Moore <[email protected]> Cc: Lv Zheng <[email protected]> Cc: "Rafael J. Wysocki" <[email protected]> Cc: Len Brown <[email protected]> Cc: Christoph Lameter <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
arunthomas · Apr 18, 2014 · 7861144 · 7861144
1 parent 82c04ff
commit 7861144
Showing 1 changed file with 5 additions and 1 deletion.
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
@@ -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);