From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sasha Levin Subject: [PATCH AUTOSEL 4.20 101/304] thermal: Fix locking in cooling device sysfs update cur_state Date: Mon, 28 Jan 2019 10:40:18 -0500 Message-ID: <20190128154341.47195-101-sashal@kernel.org> References: <20190128154341.47195-1-sashal@kernel.org> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20190128154341.47195-1-sashal@kernel.org> Sender: linux-kernel-owner@vger.kernel.org To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Thara Gopinath , Zhang Rui , Sasha Levin , linux-pm@vger.kernel.org List-Id: linux-pm@vger.kernel.org From: Thara Gopinath [ Upstream commit 68000a0d983f539c95ebe5dccd4f29535c7ac0af ] Sysfs interface to update cooling device cur_state does not currently holding cooling device lock sometimes leading to stale values in cur_state if getting updated simultanelously from user space and thermal framework. Adding the proper locking code fixes this issue. Signed-off-by: Thara Gopinath Signed-off-by: Zhang Rui Signed-off-by: Sasha Levin --- drivers/thermal/thermal_sysfs.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/drivers/thermal/thermal_sysfs.c b/drivers/thermal/thermal_sysfs.c index 2241ceae7d7f..aa99edb4dff7 100644 --- a/drivers/thermal/thermal_sysfs.c +++ b/drivers/thermal/thermal_sysfs.c @@ -712,11 +712,14 @@ cur_state_store(struct device *dev, struct device_attribute *attr, if ((long)state < 0) return -EINVAL; + mutex_lock(&cdev->lock); + result = cdev->ops->set_cur_state(cdev, state); - if (result) - return result; - thermal_cooling_device_stats_update(cdev, state); - return count; + if (!result) + thermal_cooling_device_stats_update(cdev, state); + + mutex_unlock(&cdev->lock); + return result ? result : count; } static struct device_attribute -- 2.19.1