Re: [PATCH] b43legacy: Fix a sleep-in-atomic bug in b43legacy_attr_interfmode_store

[Larry Finger]

On 06/01/2017 11:11 AM, Jonathan Corbet wrote:
> On Thu, 01 Jun 2017 09:05:07 +0800
> Jia-Ju Bai <baijiaju1990@xxxxxxx> wrote:
>
> > I admit my patches are not well tested, and they may not well fix the bugs.
> > I am looking forward to opinions and suggestions :)
>
> May I politely suggest that sending out untested locking changes is a
> dangerous thing to do?  You really should not be changing the locking in a
> piece of kernel code without understanding very well what the lock is
> protecting and being able to say why your changes are safe.  Without that,
> the risk of introducing subtle bugs is very high.
>
> It looks like you have written a useful tool that could help us to make
> the kernel more robust.  If you are interested in my suggestion, I would
> recommend that you post the sleep-in-atomic scenarios that you are
> finding, but refrain from "fixing" them in any case where you cannot offer
> a strong explanation of why your fix is correct.
>
> Thanks for working to find bugs in the kernel!

I agree with the suggestion above. Locking changes should only be done in 
conjunction with testing by someone that actually has the hardware.

Larry