From patchwork Mon Jan 11 17:35:53 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Juri Lelli X-Patchwork-Id: 59557 Delivered-To: patch@linaro.org Received: by 10.112.130.2 with SMTP id oa2csp2252201lbb; Mon, 11 Jan 2016 09:38:27 -0800 (PST) X-Received: by 10.66.163.231 with SMTP id yl7mr177730289pab.141.1452533883944; Mon, 11 Jan 2016 09:38:03 -0800 (PST) Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id h75si25314310pfd.5.2016.01.11.09.38.03; Mon, 11 Jan 2016 09:38:03 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761292AbcAKRhn (ORCPT + 29 others); Mon, 11 Jan 2016 12:37:43 -0500 Received: from foss.arm.com ([217.140.101.70]:57273 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761224AbcAKRhg (ORCPT ); Mon, 11 Jan 2016 12:37:36 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id C6C464AE; Mon, 11 Jan 2016 09:37:01 -0800 (PST) Received: from e106622-lin.cambridge.arm.com (e106622-lin.cambridge.arm.com [10.1.208.152]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 687BF3F24D; Mon, 11 Jan 2016 09:37:34 -0800 (PST) From: Juri Lelli To: linux-kernel@vger.kernel.org Cc: linux-pm@vger.kernel.org, peterz@infradead.org, rjw@rjwysocki.net, viresh.kumar@linaro.org, mturquette@baylibre.com, steve.muckle@linaro.org, vincent.guittot@linaro.org, morten.rasmussen@arm.com, dietmar.eggemann@arm.com, juri.lelli@arm.com Subject: [RFC PATCH 12/19] cpufreq: fix locking of policy->rwsem in cpufreq_init_policy Date: Mon, 11 Jan 2016 17:35:53 +0000 Message-Id: <1452533760-13787-13-git-send-email-juri.lelli@arm.com> X-Mailer: git-send-email 2.2.2 In-Reply-To: <1452533760-13787-1-git-send-email-juri.lelli@arm.com> References: <1452533760-13787-1-git-send-email-juri.lelli@arm.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org There are paths in cpufreq_init_policy where policy is used, but its rwsem is not held. Fix it. Cc: "Rafael J. Wysocki" Cc: Viresh Kumar Signed-off-by: Juri Lelli --- drivers/cpufreq/cpufreq.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) -- 2.2.2 diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index e7fc5c9..2c7cc6c73 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -998,21 +998,24 @@ static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, unsigned int cp { int ret = 0; + down_write(&policy->rwsem); + /* Has this CPU been taken care of already? */ - if (cpumask_test_cpu(cpu, policy->cpus)) + if (cpumask_test_cpu(cpu, policy->cpus)) { + up_write(&policy->rwsem); return 0; + } if (has_target()) { ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP); if (ret) { + up_write(&policy->rwsem); pr_err("%s: Failed to stop governor\n", __func__); return ret; } } - down_write(&policy->rwsem); cpumask_set_cpu(cpu, policy->cpus); - up_write(&policy->rwsem); if (has_target()) { ret = __cpufreq_governor(policy, CPUFREQ_GOV_START); @@ -1020,10 +1023,12 @@ static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, unsigned int cp ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); if (ret) { + up_write(&policy->rwsem); pr_err("%s: Failed to start governor\n", __func__); return ret; } } + up_write(&policy->rwsem); return 0; }