From patchwork Mon Jan 11 17:35:55 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Juri Lelli X-Patchwork-Id: 59562 Delivered-To: patch@linaro.org Received: by 10.112.130.2 with SMTP id oa2csp2252880lbb; Mon, 11 Jan 2016 09:39:42 -0800 (PST) X-Received: by 10.66.55.72 with SMTP id q8mr182470629pap.136.1452533981889; Mon, 11 Jan 2016 09:39:41 -0800 (PST) Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id o6si29806745pfa.166.2016.01.11.09.39.41; Mon, 11 Jan 2016 09:39:41 -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 S1761484AbcAKRjk (ORCPT + 29 others); Mon, 11 Jan 2016 12:39:40 -0500 Received: from foss.arm.com ([217.140.101.70]:57283 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761245AbcAKRhl (ORCPT ); Mon, 11 Jan 2016 12:37:41 -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 03CB75E9; Mon, 11 Jan 2016 09:37:06 -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 EE0643F24D; Mon, 11 Jan 2016 09:37:38 -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 14/19] cpufreq: fix locking of policy->rwsem in cpufreq_offline_finish Date: Mon, 11 Jan 2016 17:35:55 +0000 Message-Id: <1452533760-13787-15-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_offline_prepare 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 | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) -- 2.2.2 diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 91158b0..ba452c3 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -1381,9 +1381,13 @@ static void cpufreq_offline_finish(unsigned int cpu) return; } + down_write(&policy->rwsem); + /* Only proceed for inactive policies */ - if (!policy_is_inactive(policy)) + if (!policy_is_inactive(policy)) { + up_write(&policy->rwsem); return; + } /* If cpu is last user of policy, free policy */ if (has_target()) { @@ -1392,6 +1396,8 @@ static void cpufreq_offline_finish(unsigned int cpu) pr_err("%s: Failed to exit governor\n", __func__); } + up_write(&policy->rwsem); + /* * Perform the ->exit() even during light-weight tear-down, * since this is a core component, and is essential for the