Re: [PATCH v2 0/3] printk: Deadlock in NMI regression

From: Sergey Senozhatsky
Date: Wed Jun 27 2018 - 10:16:34 EST


On (06/27/18 16:08), Petr Mladek wrote:
> The commit 719f6a7040f1bdaf96 ("printk: Use the main logbuf in NMI
> when logbuf_lock is available") brought back the possible deadlocks
> in printk() and NMI.
>
> This is rework of the proposed fix, see
> https://lkml.kernel.org/r/20180606111557.xzs6l3lkvg7lq3ts@xxxxxxxxxxxxxxx
>
> I realized that we could rather easily move the check to vprintk_func()
> and still avoid any race. I believe that this is a win-win solution.
>
>
> Changes against v1:
>
> + Move the check from vprintk_emit() to vprintk_func()
> + More straightforward commit message
> + Fix build with CONFIG_PRINTK_NMI disabled

Did I miss out V1?

> Petr Mladek (3):
> printk: Split the code for storing a message into the log buffer
> printk: Create helper function to queue deferred console handling
> printk/nmi: Prevent deadlock when accessing the main log buffer in NMI

Patch 3/3 is not in my mailbox, somehow [I checked the spam folder].
I'm not Cc-ed or the message got lost somewhere before it reached my
gmail?

-ss