Re: [PATCH] regulator: core: Move regulator release to avoiddeadlock

From: Charles Keepax
Date: Wed Oct 31 2012 - 08:01:11 EST


On Wed, Oct 31, 2012 at 04:03:59PM +0530, Laxman Dewangan wrote:
> On Monday 29 October 2012 09:44 PM, Mark Brown wrote:
>> * PGP Signed by an unknown key
>>
>> On Mon, Oct 29, 2012 at 09:33:33AM +0000, Charles Keepax wrote:
>>> regulator_put function was called whilst holding the
>>> regulator_list_mutex, which is also locked from regulator_put. This
>>> causes deadlock when failing to register a regulator.
>> Applied, thanks.
>
> This patch create the crash in following case:
> - If there is of rail supply and supply does not found. In this case it
> goes to scrub and rdev->supply at this point shows NULL but when call
> the function device_unregister(&rdev->dev), the rdev->supply becomes
> random pointer.

Yeah that is a problem, sorry for missing this.

>
> What happen if we do the device_unregister() outside the mutex lock?

It would look reasonable to me, but I think it is going to make
more sense for someone with more experience than myself to have a
closer look at what can be done.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/