On 11/15/2013 05:32 PM, Rafael J. Wysocki wrote:
On Friday, November 15, 2013 05:16:31 PM Shuah Khan wrote:
On 11/15/2013 05:21 PM, Rafael J. Wysocki wrote:
On Friday, November 15, 2013 05:03:57 PM Shuah Khan wrote:
device_wakeup_enable() uses dev_name(dev) as the wakeup source name.
When it gets called with a device with its name not yet set, ws structure
with ws->name = NULL gets created.
When kernel is booted with wakeup_source_activate enabled, it will panic
when the trace point code tries to derefernces ws->name.
Change device_wakeup_enable() to check for dev_name(dev) null condition
and return -EINVAL to avoid panics when device_wakeup_enable() gets called
before device is fully initialized with its name.
return -EINVAL;
Can you please use WARN_ON(!dev_name(dev)) here? While I agree that it is a
bad idea to crash the kernel because dev has no name, that indicates a driver
bug that shouldn't be too easy to ignore.
Thanks!
Right. ok I will re-cut the patch with WARN_ON and send it. fyi I did
send fix for the driver (power_supply) as well.
http://www.kernelhub.org/?msg=362354&p=2
That's OK (thanks for taking care of this), but there may be more brilliant
stuff like that in the future and people should see right away that something's
wrong in those cases.
Rafael/Anton/David,
I added WARN_ON and testing the patch. We have two instance of
device_wakeup_enable() calls with null dev_name during boot. Both are
from power_supply_register(). One when AC Adapter [ADP1] is added and
the second when device: 'BAT1' gets added.
[ 4.412959] device_wakeup_enable() called with null device nme
[ 4.412967] device: 'ADP1': device_add
[ 4.460190] device_wakeup_enable() called with null device nme
[ 4.460197] device: 'BAT1': device_add
I think adding WARN_ON to device_wakeup_enable() and fix to
power_supply_register() should go in as a dependent patch series, to
avoid panics during boot. As soon as the device_wakeup_enable() WARN_ON
goes in, I suspect most laptops will panic during boot, similar to what
I am seeing in my testing. Thoughts?
I will send these fixes, maybe these two can be funneled through PM tree
with power_supply maintainers ACK for the power_supply_register() fix.
thanks,
-- Shuah
--
Shuah Khan
Senior Linux Kernel Developer - Open Source Group
Samsung Research America(Silicon Valley)
shuah.kh@xxxxxxxxxxx | (970) 672-0658
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html