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authorTomas Winkler <tomas.winkler@intel.com>2012-12-16 13:23:17 +0200
committerWim Van Sebroeck <wim@iguana.be>2012-12-19 22:25:11 +0100
commitd692170037c0338b31dac5ac4722c1360a4b5257 (patch)
tree0de83610a209aaefdb908292e79b875c0d865d6d /drivers/misc
parent8c4c419ca3bd5a5b3389114e037a9d17bdec3a5f (diff)
watchdog: mei: avoid oops in watchdog unregister code path
With commit c7d3df3 "mei: use internal watchdog device registration tracking" will crash the kernel on shutdown path on systems where ME watchdog is not present. Since the watchdog was never initialized in such case the WDOG_UNREGISTERED bit is never set and the system crashes on access to uninitialized variables down the path. To solve the issue we query for NULL on watchdog driver driver_data to check whether the device is registered. This is handled in the driver and doesn't depend on watchdog core internals. Cc: Borislav Petkov <bp@alien8.de> Cc: Wanlong Gao <gaowanlong@cn.fujitsu.com> Signed-off-by: Jerry Snitselaar <jerry.snitselaar@oracle.com> Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Diffstat (limited to 'drivers/misc')
-rw-r--r--drivers/misc/mei/wd.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/misc/mei/wd.c b/drivers/misc/mei/wd.c
index 636409f9667..9299a8c29a6 100644
--- a/drivers/misc/mei/wd.c
+++ b/drivers/misc/mei/wd.c
@@ -370,7 +370,7 @@ void mei_watchdog_register(struct mei_device *dev)
void mei_watchdog_unregister(struct mei_device *dev)
{
- if (test_bit(WDOG_UNREGISTERED, &amt_wd_dev.status))
+ if (watchdog_get_drvdata(&amt_wd_dev) == NULL)
return;
watchdog_set_drvdata(&amt_wd_dev, NULL);