linux-kernel - Re: [BUG] printk/nbcon.c: watchdog BUG: softlockup

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date: Thu, 20 Jun 2024 11:32:46 +0200
From: Sebastian Andrzej Siewior <bigeasy@...utronix.de>
To: Derek Barbosa <debarbos@...hat.com>
Cc: pmladek@...e.com, rostedt@...dmis.org, john.ogness@...utronix.de,
	senozhatsky@...omium.org, linux-rt-users@...r.kernel.org,
	linux-kernel@...r.kernel.org, williams@...hat.com,
	jlelli@...hat.com, ahalaney@...hat.com, lgoncalv@...hat.com,
	jwyatt@...hat.com, aubaker@...hat.com
Subject: Re: [BUG] printk/nbcon.c: watchdog BUG: softlockup - CPU#x stuck for
 78s

On 2024-06-20 09:15:45 [+0200], To Derek Barbosa wrote:
> On 2024-06-18 13:37:42 [-0400], Derek Barbosa wrote:
> > Hi,
> Hi,
> 
> > We have a modicum of reasonable suspicion to believe that nbcon_reacquire, or
> > some other nbcon mechanism *may* be causing such behavior.
> 
> Does this help?
> 
> diff --git a/kernel/printk/nbcon.c b/kernel/printk/nbcon.c
> index bb9689f94d302..0813ce88a49c5 100644
> --- a/kernel/printk/nbcon.c
> +++ b/kernel/printk/nbcon.c
> @@ -1119,6 +1119,7 @@ static int nbcon_kthread_func(void *__console)
>  		}
>  
>  		console_srcu_read_unlock(cookie);
> +		cond_resched();
>  
>  	} while (backlog);
>  

Okay. Works here on a 144 CPU box without CONFIG_PREEMPT.

Sebastian