From patchwork Fri Mar 25 09:44:36 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kant Fan X-Patchwork-Id: 12791392 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 94D87C433FE for ; Fri, 25 Mar 2022 09:45:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243356AbiCYJqm (ORCPT ); Fri, 25 Mar 2022 05:46:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51342 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243192AbiCYJqm (ORCPT ); Fri, 25 Mar 2022 05:46:42 -0400 Received: from out29-173.mail.aliyun.com (out29-173.mail.aliyun.com [115.124.29.173]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D43E569CC5; Fri, 25 Mar 2022 02:45:03 -0700 (PDT) X-Alimail-AntiSpam: AC=CONTINUE;BC=0.0745066|-1;BR=01201311R121S62rulernew998_84748_2000303;CH=blue;DM=|CONTINUE|false|;DS=CONTINUE|ham_alarm|0.0264882-0.0159725-0.957539;FP=0|0|0|0|0|-1|-1|-1;HT=ay29a033018047194;MF=kant@allwinnertech.com;NM=1;PH=DS;RN=11;RT=11;SR=0;TI=SMTPD_---.NCJqz9-_1648201498; Received: from sunxibot.allwinnertech.com(mailfrom:kant@allwinnertech.com fp:SMTPD_---.NCJqz9-_1648201498) by smtp.aliyun-inc.com(33.13.201.118); Fri, 25 Mar 2022 17:44:59 +0800 From: Kant Fan To: rui.zhang@intel.com, daniel.lezcano@linaro.org, javi.merino@kernel.org, edubezval@gmail.com, orjan.eide@arm.com Cc: amitk@kernel.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, allwinner-opensource-support@allwinnertech.com, Kant Fan , stable@vger.kernel.org Subject: [PATCH] thermal: devfreq_cooling: use local ops instead of global ops Date: Fri, 25 Mar 2022 17:44:36 +0800 Message-Id: <20220325094436.101419-1-kant@allwinnertech.com> X-Mailer: git-send-email 2.29.0 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org commit 7b62935828266658714f81d4e9176edad808dc70 upstream. Fix access illegal address problem in following condition: There are muti devfreq cooling devices in system, some of them register with dfc_power but other does not, power model ops such as state2power will append to global devfreq_cooling_ops when the cooling device with dfc_power register. It makes the cooling device without dfc_power also use devfreq_cooling_ops after appending when register later by of_devfreq_cooling_register_power() or of_devfreq_cooling_register(). IPA governor regards the cooling devices without dfc_power as a power actor because they also have power model ops, and will access illegal address at dfc->power_ops when execute cdev->ops->get_requested_power or cdev->ops->power2state. As the calltrace below shows: Unable to handle kernel NULL pointer dereference at virtual address 00000008 ... calltrace: [] devfreq_cooling_power2state+0x24/0x184 [] power_actor_set_power+0x54/0xa8 [] power_allocator_throttle+0x770/0x97c [] handle_thermal_trip+0x1b4/0x26c [] thermal_zone_device_update+0x154/0x208 [] process_one_work+0x1ec/0x36c [] worker_thread+0x204/0x2ec [] kthread+0x140/0x154 [] ret_from_fork+0x14/0x2c Fixes: a76caf55e5b35 ("thermal: Add devfreq cooling") Cc: stable@vger.kernel.org # 4.4+ Signed-off-by: Kant Fan --- drivers/thermal/devfreq_cooling.c | 25 ++++++++++++++++++------- 1 file changed, 18 insertions(+), 7 deletions(-) diff --git a/drivers/thermal/devfreq_cooling.c b/drivers/thermal/devfreq_cooling.c index dfab49a67252..d36f70513e6a 100644 --- a/drivers/thermal/devfreq_cooling.c +++ b/drivers/thermal/devfreq_cooling.c @@ -462,22 +462,29 @@ of_devfreq_cooling_register_power(struct device_node *np, struct devfreq *df, { struct thermal_cooling_device *cdev; struct devfreq_cooling_device *dfc; + struct thermal_cooling_device_ops *ops; char dev_name[THERMAL_NAME_LENGTH]; int err; - dfc = kzalloc(sizeof(*dfc), GFP_KERNEL); - if (!dfc) + ops = kmemdup(&devfreq_cooling_ops, sizeof(*ops), GFP_KERNEL); + if (!ops) return ERR_PTR(-ENOMEM); + dfc = kzalloc(sizeof(*dfc), GFP_KERNEL); + if (!dfc) { + err = -ENOMEM; + goto free_ops; + } + dfc->devfreq = df; if (dfc_power) { dfc->power_ops = dfc_power; - devfreq_cooling_ops.get_requested_power = + ops->get_requested_power = devfreq_cooling_get_requested_power; - devfreq_cooling_ops.state2power = devfreq_cooling_state2power; - devfreq_cooling_ops.power2state = devfreq_cooling_power2state; + ops->state2power = devfreq_cooling_state2power; + ops->power2state = devfreq_cooling_power2state; } err = devfreq_cooling_gen_tables(dfc); @@ -497,8 +504,7 @@ of_devfreq_cooling_register_power(struct device_node *np, struct devfreq *df, snprintf(dev_name, sizeof(dev_name), "thermal-devfreq-%d", dfc->id); - cdev = thermal_of_cooling_device_register(np, dev_name, dfc, - &devfreq_cooling_ops); + cdev = thermal_of_cooling_device_register(np, dev_name, dfc, ops); if (IS_ERR(cdev)) { err = PTR_ERR(cdev); dev_err(df->dev.parent, @@ -522,6 +528,8 @@ of_devfreq_cooling_register_power(struct device_node *np, struct devfreq *df, kfree(dfc->freq_table); free_dfc: kfree(dfc); +free_ops: + kfree(ops); return ERR_PTR(err); } @@ -557,10 +565,12 @@ EXPORT_SYMBOL_GPL(devfreq_cooling_register); void devfreq_cooling_unregister(struct thermal_cooling_device *cdev) { struct devfreq_cooling_device *dfc; + const struct thermal_cooling_device_ops *ops; if (!cdev) return; + ops = cdev->ops; dfc = cdev->devdata; thermal_cooling_device_unregister(dfc->cdev); @@ -570,5 +580,6 @@ void devfreq_cooling_unregister(struct thermal_cooling_device *cdev) kfree(dfc->freq_table); kfree(dfc); + kfree(ops); } EXPORT_SYMBOL_GPL(devfreq_cooling_unregister);