From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hugh Dickins Subject: Re: [PATCHv2] Thermal: Fix synchronization issues in thermal_sys.c Date: Thu, 27 Sep 2012 16:48:28 -0700 (PDT) Message-ID: References: <1348727888-11196-1-git-send-email-durgadoss.r@intel.com> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Return-path: Received: from mail-ia0-f174.google.com ([209.85.210.174]:40868 "EHLO mail-ia0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755803Ab2I0XtH (ORCPT ); Thu, 27 Sep 2012 19:49:07 -0400 Received: by iagy32 with SMTP id y32so8393iag.19 for ; Thu, 27 Sep 2012 16:49:06 -0700 (PDT) In-Reply-To: Sender: linux-next-owner@vger.kernel.org List-ID: To: lenb@kernel.org, rui.zhang@intel.com Cc: Durgadoss R , Sedat Dilek , linux-acpi@vger.kernel.org, dan.carpenter@oracle.com, linux-next@vger.kernel.org On Thu, 27 Sep 2012, Sedat Dilek wrote: > >> > >> The v2 patch does *not* fix the issue here! > >> > >> [1] https://patchwork.kernel.org/patch/1511961/ > >> > > > > I have re-tested with Linux-Next (next-20120927) plus thermal-next [1] > > pulled in and see still the same call-trace! Same here on mmotm, yes. > > > > Hugh or Dan can you confirm this works for you or not? > > Thanks in advance. > > > > [1] http://git.kernel.org/?p=linux/kernel/git/rzhang/linux.git;a=shortlog;h=refs/heads/next > > [2] http://git.kernel.org/?p=linux/kernel/git/rzhang/linux.git;a=commitdiff;h=404b134156bd9d9bc506c0974a1254806e13db2c > > > > With the attached fixup/followup patch, I can boot into my system! > But, as said yesterday... working within X, Firefox is a pain in the a**. Indeed, this works for me too, thanks. Let's get your addition out of the attachment and fold it into a v3. Mind if we change "synchronization issues" to "oops and unlocking"? [PATCHv3] Thermal: Fix oops and unlocking in thermal_sys.c This patch fixes the following mutex and NULL pointer problems in thermal_sys.c: * mutex_unlock fix in update_temperature function * mutex_unlock fix in bind_cdev function * Correct early return to continue in bind_cdev function * NULL check fix in bind_cdev function * NULL check fix in bind_tz function Reported-by: Dan Carpenter Reported-by: Sedat Dilek Reported-by: Hugh Dickins Signed-off-by: Durgadoss R Signed-off-by: Sedat Dilek Signed-off-by: Hugh Dickins --- v3: * Sedat restored necessary NULL check in bind_cdev and his signoff. * Hugh added two more comments above, his signoff, and Dan's 'Reported-by'. drivers/thermal/thermal_sys.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) --- mmotm/drivers/thermal/thermal_sys.c 2012-09-26 10:15:28.652071362 -0700 +++ linux/drivers/thermal/thermal_sys.c 2012-09-27 16:19:14.427515890 -0700 @@ -252,8 +252,8 @@ static void bind_cdev(struct thermal_coo } tzp = pos->tzp; - if (!tzp->tbp) - return; + if (!tzp || !tzp->tbp) + continue; for (i = 0; i < tzp->num_tbps; i++) { if (tzp->tbp[i].cdev || !tzp->tbp[i].match) @@ -289,7 +289,7 @@ static void bind_tz(struct thermal_zone_ goto exit; } - if (!tzp->tbp) + if (!tzp || !tzp->tbp) goto exit; list_for_each_entry(pos, &thermal_cdev_list, node) { @@ -387,12 +387,13 @@ static void update_temperature(struct th ret = tz->ops->get_temp(tz, &temp); if (ret) { pr_warn("failed to read out thermal zone %d\n", tz->id); - return; + goto exit; } tz->last_temperature = tz->temperature; tz->temperature = temp; +exit: mutex_unlock(&tz->lock); }