Re: possible deadlock in console_unlock

From: Yao HongBo
Date: Mon Feb 18 2019 - 07:10:22 EST




On 2/18/2019 1:46 PM, Sergey Senozhatsky wrote:
> Hi,
>
> On (02/16/19 15:59), Yao HongBo wrote:
>>> GFP_NOWARN is probably the best option for now. Yes, it, maybe,
>>> will not work for fault-injection cases; but printk_safe approach
>>> is harder to push for, especially given that printk_safe maybe will
>>> not even exist in the future.
>>
>> I have tried GFP_NOWARN, but the problem still exists.
>> Only print_safe contexts for tty locks can solve the problem.
>> My test scenario is falt-injection.
>
> Oh, I see. Yes, fault-injection is special.
>
> I suspect that this patch series can be helpful then
> https://lore.kernel.org/lkml/20181016050428.17966-1-sergey.senozhatsky@xxxxxxxxx/T/#u

ok, i'll try it.
Thanks.

> but first we need to figure out if printk_safe will
> stay in the kernel (this will take some time).
>
> -ss
>
>