Re: [RFC][PATCH 0/6] Use printk_safe context for TTY and UART port locks

From: Sergey Senozhatsky
Date: Tue Jun 19 2018 - 22:56:54 EST


On (06/19/18 22:34), Steven Rostedt wrote:
>
> > There is no valid reason why an UART driver should do a printk() of
> > any sort inside the critical region where the console is locked.
> >
> > Just remove those printk's, don't add new crazy locking.
>
> Perhaps we should do an audit of the console drivers and remove all
> printk, pr_* , WARN*, BUG* from them.

I think I did a terrible job explaining my motivation.

Sorry for that!


What I tried to address with my patch set was not a direct uart->printk,
but mostly all those

uart-> tty / core kernel / who knows what else -> printk

cases. When are in that special context "called from uart driver" which
can backfire on us.

-ss