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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 DE533C433E0 for ; Sat, 20 Jun 2020 19:11:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C685522D02 for ; Sat, 20 Jun 2020 19:11:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728582AbgFTTLD (ORCPT ); Sat, 20 Jun 2020 15:11:03 -0400 Received: from mail.rc.ru ([151.236.222.147]:39546 "EHLO mail.rc.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728424AbgFTTLD (ORCPT ); Sat, 20 Jun 2020 15:11:03 -0400 Received: from mail.rc.ru ([2a01:7e00:e000:1bf::1]:57848) by mail.rc.ru with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1jmitD-0005jw-Fs; Sat, 20 Jun 2020 20:10:55 +0100 Date: Sat, 20 Jun 2020 20:10:52 +0100 From: Ivan Kokshaysky To: Andrew Lunn Cc: Gregory Clement , Jason Cooper , Sebastian Hesselbarth , "Rafael J. Wysocki" , Viresh Kumar , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] cpufreq: dt: fix oops on armada37xx Message-ID: <20200620191052.GA21708@mail.rc.ru> References: <20200620164449.GA19776@mail.rc.ru> <20200620175438.GS304147@lunn.ch> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200620175438.GS304147@lunn.ch> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Jun 20, 2020 at 07:54:38PM +0200, Andrew Lunn wrote: > On Sat, Jun 20, 2020 at 05:44:49PM +0100, Ivan Kokshaysky wrote: > > Commit 0c868627e617e43a295d8 (cpufreq: dt: Allow platform specific > > intermediate callbacks) added two function pointers to the > > struct cpufreq_dt_platform_data. However, armada37xx_cpufreq_driver_init() > > has this struct (pdata) located on the stack and uses only "suspend" > > and "resume" fields. So these newly added "get_intermediate" and > > "target_intermediate" pointers are uninitialized and contain arbitrary > > non-null values, causing all kinds of trouble. > > > > For instance, here is an oops on espressobin after an attempt to change > > the cpefreq governor: > > > > [ 29.174554] Unable to handle kernel execute from non-executable memory at virtual address ffff00003f87bdc0 > > ... > > [ 29.269373] pc : 0xffff00003f87bdc0 > > [ 29.272957] lr : __cpufreq_driver_target+0x138/0x580 > > ... > > > > Fixed by zeroing out pdata before use. > > > > Signed-off-by: Ivan Kokshaysky > > Hi Ivan > > A Fixes: tag would be good. Hi Andrew, I'm not sure that "Fixes:" would be appropriate here - commit 0c868627e617 is fine by itself, it just revealed a bug in older code. Thanks for reviewing, Ivan. > Reviewed-by: Andrew Lunn > > Andrew