From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from foss.arm.com ([217.140.101.70]:51378 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754410AbcA0KVs (ORCPT ); Wed, 27 Jan 2016 05:21:48 -0500 Date: Wed, 27 Jan 2016 10:22:23 +0000 From: Juri Lelli To: "Rafael J. Wysocki" Cc: Viresh Kumar , linaro-kernel@lists.linaro.org, linux-pm@vger.kernel.org, "# v4 . 2+" , open list Subject: Re: [PATCH] cpufreq: Fix NULL reference crash while accessing policy->governor_data Message-ID: <20160127102223.GN10898@e106622-lin> References: <1297c8fc8135f8b5359f9c49d220a939c0ee640e.1453741314.git.viresh.kumar@linaro.org> <20160126095751.GJ10898@e106622-lin> <20160126180119.GK10898@e106622-lin> <30317803.WdZJECVyOY@vostro.rjw.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <30317803.WdZJECVyOY@vostro.rjw.lan> Sender: stable-owner@vger.kernel.org List-ID: On 26/01/16 23:49, Rafael J. Wysocki wrote: > On Tuesday, January 26, 2016 06:01:19 PM Juri Lelli wrote: > > On 26/01/16 09:57, Juri Lelli wrote: > > > Hi Viresh, > > > > > > On 25/01/16 22:33, Viresh Kumar wrote: > > > > There is a little race discovered by Juri, where we are able to: > > > > - create and read a sysfs file before policy->governor_data is being set > > > > to a non NULL value. > > > > OR > > > > - set policy->governor_data to NULL, and reading a file before being > > > > destroyed. > > > > > > [cut] > > > > > So, this goes away with your patch (that I forward ported) and a small > > additional fix on top of that. > > Which patch exactly is that? > As Viresh said, this is: cpufreq: Access governor's sysfs attributes without 'policy->rwsem' http://www.linux-arm.org/git?p=linux-jl.git;a=commit;h=d3eb02ed23732de2c8671377316a190c38b8fe93 Apologies for the confusion; I was already talking with Viresh on IRC about it. Best, - Juri