Re: [PATCH v1] ASoC: rt5640: Fix NULL dereference on module unload

From: Dmitry Osipenko
Date: Thu Jan 02 2020 - 10:57:20 EST


31.12.2019 03:17, Mark Brown ÐÐÑÐÑ:
> On Sun, Dec 29, 2019 at 06:04:54PM +0300, Dmitry Osipenko wrote:
>> The rt5640->jack is NULL if jack is already disabled at the time of
>> driver's module unloading.
>>
>> Unable to handle kernel NULL pointer dereference at virtual address 00000024
>> ...
>> (rt5640_set_jack [snd_soc_rt5640]) from [<bf86f7ed>] (snd_soc_component_set_jack+0x11/0x1c [snd_soc_core])
>> (snd_soc_component_set_jack [snd_soc_core]) from [<bf8675cf>] (soc_remove_component+0x1b/0x54 [snd_soc_core])
>> (soc_remove_component [snd_soc_core]) from [<bf868859>] (soc_cleanup_card_resources+0xad/0x1cc [snd_soc_core])
>
> In addition to what Takashi said:
>
> Please think hard before including complete backtraces in upstream
> reports, they are very large and contain almost no useful information
> relative to their size so often obscure the relevant content in your
> message. If part of the backtrace is usefully illustrative then it's
> usually better to pull out the relevant sections.

Yeah, perhaps it's not really useful to have backtrace in the commit's
description for the case of this patch in particular. But in general it
is very useful to have backtraces somewhere near the patch such that
online search engines, like google, could pick it up. I'll move the
backtrace below --- in v2, thanks.