From: Rusty Russell <rusty@rustcorp.com.au>
To: Ingo Molnar <mingo@elte.hu>
Cc: Alexey Dobriyan <adobriyan@sw.ru>,
akpm@osdl.org, linux-kernel@vger.kernel.org, devel@openvz.org,
tglx@linutronix.de, viro@zeniv.linux.org.uk,
pmarques@grupopie.com
Subject: Re: [PATCH RESEND 2/2] Fix some kallsyms_lookup() vs rmmod races
Date: Sat, 17 Mar 2007 20:37:18 +1100 [thread overview]
Message-ID: <1174124239.8897.41.camel@localhost.localdomain> (raw)
In-Reply-To: <20070316115154.GC30195@elte.hu>
On Fri, 2007-03-16 at 12:51 +0100, Ingo Molnar wrote:
> * Alexey Dobriyan <adobriyan@sw.ru> wrote:
>
> > [cc'ing folks whose proc files are affected]
> >
> > kallsyms_lookup() can call module_address_lookup() which iterates over
> > modules list without module_mutex taken. Comment at the top of
> > module_address_lookup() says it's for oops resolution so races are
> > irrelevant, but in some cases it's reachable from regular code:
>
> looking at the problem from another angle: wouldnt this be something
> that would benefit from freeze_processes()/unfreeze_processes(), and
> hence no locking would be required?
Actually, the list manipulation is done with stop_machine for this
reason. Alexey, is preempt enabled in your kernel?
Rusty.
next prev parent reply other threads:[~2007-03-18 0:46 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-03-16 11:44 [PATCH RESEND 2/2] Fix some kallsyms_lookup() vs rmmod races Alexey Dobriyan
2007-03-16 11:51 ` Ingo Molnar
2007-03-16 16:16 ` Paulo Marques
2007-03-16 16:18 ` Ingo Molnar
2007-03-16 17:16 ` Paulo Marques
2007-03-16 18:15 ` Andrew Morton
2007-03-16 20:27 ` Paulo Marques
2007-03-16 20:49 ` Andrew Morton
2007-03-17 10:36 ` Rusty Russell
2007-03-19 9:56 ` Alexey Dobriyan
2007-03-17 9:37 ` Rusty Russell [this message]
2007-03-19 10:21 ` Alexey Dobriyan
2007-03-19 15:17 ` Paulo Marques
2007-03-19 23:23 ` Rusty Russell
2007-03-17 9:32 ` Rusty Russell
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