Messages in this thread | | | Date | Mon, 17 Dec 2012 10:39:15 +0800 | From | Wanlong Gao <> | Subject | Re: [char-misc for 3.8] mei: avoid oops in watchdog unregister code path |
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On 12/16/2012 07:23 PM, Tomas Winkler wrote: > 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>
Fixed the panic here, thank you.
Tested-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
> --- > drivers/misc/mei/wd.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/drivers/misc/mei/wd.c b/drivers/misc/mei/wd.c > index 636409f..9299a8c 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); >
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