From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AIpwx4+ZsuEyXRk3tx9TXrHFT9F2aZKqPUFb3cCJKhcCVprT4lpwlnem4RsVcWDo03M2w6VqPjvj ARC-Seal: i=1; a=rsa-sha256; t=1523399690; cv=none; d=google.com; s=arc-20160816; b=TsLSvnotupnPuRRynIj85LLiKHB3b3iq/2j58ExkLoKYfZhLCGCPMJsxtPAR0aXbrJ IR7d3CJ5m/xBx2hAnWdERS56xTuisO+jyHDXCrxBvlBpxI73JOs8OMuWICIWK+fEar0M abiylNvoGG5cWp6H+Muhu/4s+XPUysAYoyErvzZkQv0W2tEep8F0AuIqmZ3bIZqpox+t 3LeyHzI1ToIX2R5TzavMFAecTXBhEPOwritYoMMxGEGq4X3/Q9VzIOEkfSc/lXihJm/5 XyJjJr0PgU2ZOgFxDuz+IfgOfdyXtGdjP51Sk6gUKtbdoH74O26/6TDwo3KcsCpSaWj6 vWHQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=fW9aZECdn2DuSp/ypUVov37yT1KU486Ka7m/F8E2Xx0=; b=XsrMcS4XNb/7JRq3A2qJYFmTLXYqfslarfCi2cUcTaMcrRTVZD6KNmruy6aQbRZZMV CBkADitRzEkfnUbRk49Cl7iWLWqIYWre79w3WS9WlcB0QsKsH6G9mPFkl7+aT5JN/szG 9AsSoZvBJ38bNrlql7/JGP+dvAre41wc61X7wbpJWsMHddtr4AHshGzalEnv88+8Izvr b/4JR79S5WwvP4JrjCZ9voemAhdaFdRumrrerfXtgaxrtklXWirAyEty/mjYqmRXhzjq egDNjzhA/hx6sNzWyO7+jM4HrydET0FsVO04XV4Qh27vKKrvDbOte88yQcBk8O5r2Yo5 h+6A== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.61.202 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.61.202 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Yi Zeng , Zhang Rui , Sasha Levin Subject: [PATCH 4.14 008/138] thermal: power_allocator: fix one race condition issue for thermal_instances list Date: Wed, 11 Apr 2018 00:23:18 +0200 Message-Id: <20180410212903.139209142@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180410212902.121524696@linuxfoundation.org> References: <20180410212902.121524696@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1597399820028511058?= X-GMAIL-MSGID: =?utf-8?q?1597400354088111741?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Yi Zeng [ Upstream commit a5de11d67dcd268b8d0beb73dc374de5e97f0caf ] When invoking allow_maximum_power and traverse tz->thermal_instances, we should grab thermal_zone_device->lock to avoid race condition. For example, during the system reboot, if the mali GPU device implements device shutdown callback and unregister GPU devfreq cooling device, the deleted list head may be accessed to cause panic, as the following log shows: [ 33.551070] c3 25 (kworker/3:0) Unable to handle kernel paging request at virtual address dead000000000070 [ 33.566708] c3 25 (kworker/3:0) pgd = ffffffc0ed290000 [ 33.572071] c3 25 (kworker/3:0) [dead000000000070] *pgd=00000001ed292003, *pud=00000001ed292003, *pmd=0000000000000000 [ 33.581515] c3 25 (kworker/3:0) Internal error: Oops: 96000004 [#1] PREEMPT SMP [ 33.599761] c3 25 (kworker/3:0) CPU: 3 PID: 25 Comm: kworker/3:0 Not tainted 4.4.35+ #912 [ 33.614137] c3 25 (kworker/3:0) Workqueue: events_freezable thermal_zone_device_check [ 33.620245] c3 25 (kworker/3:0) task: ffffffc0f32e4200 ti: ffffffc0f32f0000 task.ti: ffffffc0f32f0000 [ 33.629466] c3 25 (kworker/3:0) PC is at power_allocator_throttle+0x7c8/0x8a4 [ 33.636609] c3 25 (kworker/3:0) LR is at power_allocator_throttle+0x808/0x8a4 [ 33.643742] c3 25 (kworker/3:0) pc : [] lr : [] pstate: 20000145 [ 33.652874] c3 25 (kworker/3:0) sp : ffffffc0f32f3bb0 [ 34.468519] c3 25 (kworker/3:0) Process kworker/3:0 (pid: 25, stack limit = 0xffffffc0f32f0020) [ 34.477220] c3 25 (kworker/3:0) Stack: (0xffffffc0f32f3bb0 to 0xffffffc0f32f4000) [ 34.819822] c3 25 (kworker/3:0) Call trace: [ 34.824021] c3 25 (kworker/3:0) Exception stack(0xffffffc0f32f39c0 to 0xffffffc0f32f3af0) [ 34.924993] c3 25 (kworker/3:0) [] power_allocator_throttle+0x7c8/0x8a4 [ 34.933184] c3 25 (kworker/3:0) [] handle_thermal_trip.part.25+0x70/0x224 [ 34.941545] c3 25 (kworker/3:0) [] thermal_zone_device_update+0xc0/0x20c [ 34.949818] c3 25 (kworker/3:0) [] thermal_zone_device_check+0x20/0x2c [ 34.957924] c3 25 (kworker/3:0) [] process_one_work+0x168/0x458 [ 34.965414] c3 25 (kworker/3:0) [] worker_thread+0x13c/0x4b4 [ 34.972650] c3 25 (kworker/3:0) [] kthread+0xe8/0xfc [ 34.979187] c3 25 (kworker/3:0) [] ret_from_fork+0x10/0x40 [ 34.986244] c3 25 (kworker/3:0) Code: f9405e73 eb1302bf d102e273 54ffc460 (b9402a61) [ 34.994339] c3 25 (kworker/3:0) ---[ end trace 32057901e3b7e1db ]--- Signed-off-by: Yi Zeng Signed-off-by: Zhang Rui Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/thermal/power_allocator.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/thermal/power_allocator.c +++ b/drivers/thermal/power_allocator.c @@ -523,6 +523,7 @@ static void allow_maximum_power(struct t struct thermal_instance *instance; struct power_allocator_params *params = tz->governor_data; + mutex_lock(&tz->lock); list_for_each_entry(instance, &tz->thermal_instances, tz_node) { if ((instance->trip != params->trip_max_desired_temperature) || (!cdev_is_power_actor(instance->cdev))) @@ -534,6 +535,7 @@ static void allow_maximum_power(struct t mutex_unlock(&instance->cdev->lock); thermal_cdev_update(instance->cdev); } + mutex_unlock(&tz->lock); } /**