linux-kernel - Re: [PATCH v8] kernel, add panic_on

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] [day] [month] [year] [list]

Message-ID: <545E1AB1.9030001@redhat.com>
Date:	Sat, 08 Nov 2014 08:29:21 -0500
From:	Prarit Bhargava <prarit@...hat.com>
To:	David Rientjes <rientjes@...gle.com>
CC:	Vivek Goyal <vgoyal@...hat.com>, linux-kernel@...r.kernel.org,
	Jonathan Corbet <corbet@....net>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Rusty Russell <rusty@...tcorp.com.au>,
	"H. Peter Anvin" <hpa@...or.com>, Andi Kleen <ak@...ux.intel.com>,
	Masami Hiramatsu <masami.hiramatsu.pt@...achi.com>,
	Fabian Frederick <fabf@...net.be>,
	isimatu.yasuaki@...fujitsu.com, jbaron@...mai.com,
	linux-doc@...r.kernel.org, kexec@...ts.infradead.org,
	linux-api@...r.kernel.org
Subject: Re: [PATCH v8] kernel, add panic_on_warn



On 11/07/2014 04:09 PM, David Rientjes wrote:
> On Fri, 7 Nov 2014, Prarit Bhargava wrote:
> 
>> There very much is.  Consider a thread that hits a WARN() and then panics.  Then
>> somewhere in the panic code the thread hits another WARN() ... and then panics
>> again.  Previously this would have caused the system to "finish" panick'ing.
>> Now it makes the system hang.
>>
> 
> Then we're back to square one which is what is obviously the intent of 
> your patch and the comment that goes along with it: 

My original reply pointed out that the comment was wrong.

we want to clear
> panic_on_warn once and not allow multiple panic().  

On _this_ thread.  The multiple panic across threads cannot occur.

So why not just add
> the necessary synchronization to make sure that happens when WARN() 
> happens on two cpus simultaneously?

See above.

P.

> 
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/