Re: [PATCH 3/3] oprofile, x86: Fix crash when unloading module (timer mode)

[Robert R. <rob...@am...>]

On 13.12.11 14:40:02, Greg KH wrote:
> On Tue, Dec 13, 2011 at 12:40:36AM +0100, Robert Richter wrote:
> > Fix for stable kernels v2.6.28.y to v2.6.34.y. This patch is for .32.
> > 
> > Oprofile crashs while unlaoding modules and if in timer mode. Timer
> > mode is the fallback if the architectural initialization fails. The
> > pointer variable model is then used uninitialzied during exit causing
> > a NULL pointer dereference.
> > 
> > It can be triggered with kernel parameters oprofile.timer=1 nolapic
> > used. Happens esp. in virtual machine environments.
> 
> What is the corrisponding patch in Linus's tree for this patch?

This is a stable only fix. I don't remember exactly, but either I got
a bug report for a stable or suse kernel or we observed a related but
not identical problem in the upstream kernel:

 97f7f81 oprofile, x86: Fix crash when unloading module (nmi timer mode)

and then started testing various modes for various kernels and
distros. Due to changes in Linus's tree the bug disappeared there.

-Robert

-- 
Advanced Micro Devices, Inc.
Operating System Research Center