linux-kernel - Re: [PATCH 3.0] perf,x86: fix kernel crash with PEBS/BTS after suspend/resume

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]

Date:	Thu, 21 Mar 2013 02:41:46 +0000
From:	Ben Hutchings <ben@...adent.org.uk>
To:	shuah.khan@...com
Cc:	eranian@...gle.com, Greg KH <gregkh@...uxfoundation.org>,
	a.p.zijlstra@...llo.nl, paulus@...ba.org, mingo@...e.hu,
	acme@...stprotocols.net, tglx@...utronix.de, hpa@...or.com,
	pavel@....cz, rafael.j.wysocki@...el.com,
	LKML <linux-kernel@...r.kernel.org>,
	torvalds@...ux-foundation.org, peterz@...radead.org,
	Andrew Morton <akpm@...ux-foundation.org>, jolsa@...hat.com,
	ak@...ux.intel.com, stable <stable@...r.kernel.org>,
	shuahkhan@...il.com
Subject: Re: [PATCH 3.0] perf,x86: fix kernel crash with PEBS/BTS after
 suspend/resume

On Fri, 2013-03-15 at 18:57 -0600, Shuah Khan wrote:
> This patch fixes a kernel crash when using precise sampling (PEBS)
> after a suspend/resume. Turns out the CPU notifier code is not invoked
> on CPU0 (BP). Therefore, the DS_AREA (used by PEBS) is not restored properly
> by the kernel and keeps it power-on/resume value of 0 causing any PEBS
> measurement to crash when running on CPU0.
> 
> The workaround is to add a hook in the actual resume code to restore
> the DS Area MSR value. It is invoked for all CPUS. So for all but CPU0,
> the DS_AREA will be restored twice but this is harmless.
> 
> Upstream commit id: 1d9d8639c063caf6efc2447f5f26aa637f844ff6
> 
> Reported-by: Linus Torvalds <torvalds@...ux-foundation.org>
> Signed-off-by: Stephane Eranian <eranian@...gle.com>
> Signed-off-by: Linus Torvalds <torvalds@...ux-foundation.org>
> Signed-off-by: Shuah Khan <shuah.khan@...com>
> CC: stable@...r.kernel.org 3.0
[...]

I've queued this up for 3.2 (though context was different again), along
with the following fix-ups:

commit 2a6e06b2aed6995af401dcd4feb5e79a0c7ea554
Author: Linus Torvalds <torvalds@...ux-foundation.org>
Date:   Sun Mar 17 15:44:43 2013 -0700

    perf,x86: fix wrmsr_on_cpu() warning on suspend/resume

commit 6c4d3bc99b3341067775efd4d9d13cc8e655fd7c
Author: David Rientjes <rientjes@...gle.com>
Date:   Sun Mar 17 15:49:10 2013 -0700

    perf,x86: fix link failure for non-Intel configs

Ben.

-- 
Ben Hutchings
It is easier to write an incorrect program than to understand a correct one.

Download attachment "signature.asc" of type "application/pgp-signature" (829 bytes)