From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7034CC282DD for ; Thu, 23 May 2019 21:59:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 40DFE217F9 for ; Thu, 23 May 2019 21:59:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="QWbKFbkn" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387734AbfEWV7C (ORCPT ); Thu, 23 May 2019 17:59:02 -0400 Received: from mail-qt1-f193.google.com ([209.85.160.193]:33173 "EHLO mail-qt1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387616AbfEWV7B (ORCPT ); Thu, 23 May 2019 17:59:01 -0400 Received: by mail-qt1-f193.google.com with SMTP id z5so2321231qtb.0; Thu, 23 May 2019 14:59:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=lTgN7h3hdKr1+n0VjmGc/qWeMMTNBbp9DYutgOmMsBE=; b=QWbKFbknKqScP8lkJNlpzZhJFZIFQqaNViglb5lX/qE5mAIVvrSs1mEANeC2R2rz4W vr2CQALElWfwHN3hYOMXmx3SyeYeHL1CwqyJQXQ6KHiLEKVwgpCcTNUDnoY4kCe8slfe 29pDR7UlZXXz1zRY3hWKJ+8pE/ZKtMUNCNmBOZxc3X1TzU/ZMrBCX5LhCOUceJwrwbjY sTWp/DdpTvLlkimimWAkKobngh+PBCAeK0yI26t/venNA1qTnL/XlmtG4AYB/YtjmuKk zQXUp/gj8XzS9blh+3/3q1WefBLkyFlZo/uJPyCyUu1znC+wanluCi/b1pU20wbHTKQM 6NSg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=lTgN7h3hdKr1+n0VjmGc/qWeMMTNBbp9DYutgOmMsBE=; b=uDC7PjEmqOHOK9Ueb02TE86HJzGFWbN2oh6o2pFAMDT+vaifmWJXrDLeF6+7pu5pm3 +zlGO2SibfRW4tREijfCCM8xqfD+Z7dxPtM8nhMsU4xs8InVV+anouz2wAZhVxx8ldD/ wlGn+5jHIPt2KKd3/WmJwv7owbXsqFOOFBcLj1P+BjTjFgz39VaWPiMHHRt+Vl3wm1y7 z+PD6Tdt5QA/w6n6PqlskTdCNpgfwKYzx31DcubPYR2xVuIZhyS58JGNQp+eNVOCFu61 ZihbRuIUwIZ7KxpQxd7UFyrG8MdHpJUbVUqrtifG4oTnJBb05+w8yIEEIlD47vGRdFdo /QNA== X-Gm-Message-State: APjAAAWV/dgo3mOl3iJWbAdWHhy84qhd4b2sSusvHSPpUXOhTOOBZqWf Z+BfPt9KPMUSsmW3WFi7yLKStlJMsnQ= X-Google-Smtp-Source: APXvYqwhxl26lCFqQbvw0xH5Wts3d1RmkKlYkbFIX4IScnu1FnkZLxIMiLvv14t5bKn8SQu61Ssiqg== X-Received: by 2002:a0c:b621:: with SMTP id f33mr49951528qve.199.1558648740234; Thu, 23 May 2019 14:59:00 -0700 (PDT) Received: from localhost ([2601:184:4780:7861:5010:5849:d76d:b714]) by smtp.gmail.com with ESMTPSA id b11sm300127qtt.6.2019.05.23.14.58.59 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Thu, 23 May 2019 14:58:59 -0700 (PDT) From: Rob Clark To: linux-arm-msm@vger.kernel.org Cc: Rob Clark , MyungJoo Ham , Kyungmin Park , Chanwoo Choi , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] PM / devfreq: try_then_request_governor should not return NULL Date: Thu, 23 May 2019 14:58:45 -0700 Message-Id: <20190523215853.16622-1-robdclark@gmail.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org From: Rob Clark The two spots it is called expect either an IS_ERR() or a valid pointer, but not NULL. Fixes this crash that I came across: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000030 Mem abort info: ESR = 0x96000005 Exception class = DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 Data abort info: ISV = 0, ISS = 0x00000005 CM = 0, WnR = 0 [0000000000000030] user address but active_mm is swapper Internal error: Oops: 96000005 [#1] PREEMPT SMP Modules linked in: Process kworker/2:1 (pid: 212, stack limit = 0x(____ptrval____)) CPU: 2 PID: 212 Comm: kworker/2:1 Not tainted 5.1.0-43338-g460e6984675c-dirty #54 Hardware name: Google Cheza (rev3+) (DT) Workqueue: events deferred_probe_work_func pstate: 00c00009 (nzcv daif +PAN +UAO) pc : devfreq_add_device+0x2e4/0x410 lr : devfreq_add_device+0x2d4/0x410 sp : ffffff8013d93740 x29: ffffff8013d93790 x28: ffffffc0f54f8670 x27: 0000000000000001 x26: 0000000000000007 x25: ffffff80124abfd8 x24: 0000000000000000 x23: ffffffc0fabc4048 x22: ffffffc0fabc4388 x21: ffffffc0fabc4010 x20: ffffffc0fa243010 x19: ffffffc0fabc4000 x18: 0000000091c3d373 x17: 0000000000000400 x16: 000000000000001a x15: 000000019e06d400 x14: 0000000000000001 x13: 0000000000000000 x12: 00000000000006b6 x11: 0000000000000000 x10: 0000000000000000 x9 : ffffffc0fa18ba00 x8 : 0000000000000000 x7 : 0000000000000000 x6 : ffffff80127a3d9a x5 : ffffff8013d93550 x4 : 0000000000000000 x3 : 0000000000000000 x2 : 0000000000000000 x1 : 00000000000000fe x0 : 0000000000000000 Call trace: devfreq_add_device+0x2e4/0x410 devm_devfreq_add_device+0x64/0xac msm_gpu_init+0x320/0x5c0 adreno_gpu_init+0x21c/0x274 a6xx_gpu_init+0x68/0xf4 adreno_bind+0x158/0x284 component_bind_all+0x110/0x204 msm_drm_bind+0x118/0x5b8 try_to_bring_up_master+0x15c/0x19c component_master_add_with_match+0xb4/0xec msm_pdev_probe+0x1f0/0x27c platform_drv_probe+0x90/0xb0 really_probe+0x120/0x298 driver_probe_device+0x64/0xfc __device_attach_driver+0x8c/0xa4 bus_for_each_drv+0x88/0xd0 __device_attach+0xac/0x134 device_initial_probe+0x20/0x2c bus_probe_device+0x34/0x90 deferred_probe_work_func+0x74/0xac process_one_work+0x210/0x428 worker_thread+0x278/0x3e4 kthread+0x120/0x130 ret_from_fork+0x10/0x18 Code: aa0003f8 b13ffc1f 54000762 f901c278 (f9401b08) ---[ end trace a6ecc18ce5894375 ]--- Kernel panic - not syncing: Fatal exception Signed-off-by: Rob Clark --- drivers/devfreq/devfreq.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index 0ae3de76833b..d29f66f0e52a 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -254,7 +254,7 @@ static struct devfreq_governor *try_then_request_governor(const char *name) /* Restore previous state before return */ mutex_lock(&devfreq_list_lock); if (err) - return NULL; + return ERR_PTR(err); governor = find_devfreq_governor(name); } -- 2.20.1