Re: [PATCH v8 13/19] locking/rwsem: Make rwsem->owner an atomic_long_t

From: Luis Henriques
Date: Sat Jul 20 2019 - 05:32:58 EST


Luis Henriques <lhenriques@xxxxxxxx> writes:

> "Linus Torvalds" <torvalds@xxxxxxxxxxxxxxxxxxxx> writes:
>
>> On Fri, Jul 19, 2019 at 12:32 PM Waiman Long <longman@xxxxxxxxxx> wrote:
>>>
>>> This patch shouldn't change the behavior of the rwsem code. The code
>>> only access data within the rw_semaphore structures. I don't know why it
>>> will cause a KASAN error. I will have to reproduce it and figure out
>>> exactly which statement is doing the invalid access.
>>
>> The stack traces should show line numbers if you run them through
>> scripts/decode_stacktrace.sh.
>>
>> You need to have debug info enabled for that, though.
>>
>> Luis?
>>
>> Linus
>
> Yep, sure. And I should have done this in the initial report. It's a
> different trace, I had to recompile the kernel.
>
> (I'm also adding Jeff to the CC list.)
>

Ah, and I also managed to reproduce this on btrfs so I guess this rules
out a bug in the filesystem code.

Cheers,
--
Luis