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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 A6630C32789 for ; Fri, 2 Nov 2018 07:42:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 682072081F for ; Fri, 2 Nov 2018 07:42:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 682072081F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728431AbeKBQsZ (ORCPT ); Fri, 2 Nov 2018 12:48:25 -0400 Received: from mx2.suse.de ([195.135.220.15]:58508 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728059AbeKBQsZ (ORCPT ); Fri, 2 Nov 2018 12:48:25 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 8538DADF4; Fri, 2 Nov 2018 07:42:10 +0000 (UTC) Date: Fri, 02 Nov 2018 08:42:10 +0100 Message-ID: From: Takashi Iwai To: Rohit kumar Cc: plai@codeaurora.org, bgoswami@codeaurora.org, lgirdwood@gmail.com, broonie@kernel.org, perex@perex.cz, tiwai@suse.com, alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org, rohkumar@qti.qualcomm.com, srinivas.kandagatla@linaro.org Subject: Re: [alsa-devel] [PATCH] ASoC: core: Invoke pcm_new() for all DAI-link In-Reply-To: <1541075929-29323-1-git-send-email-rohitkr@codeaurora.org> References: <1541075929-29323-1-git-send-email-rohitkr@codeaurora.org> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI/1.14.6 (Maruoka) FLIM/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL/10.8 Emacs/26 (x86_64-suse-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 01 Nov 2018 13:38:49 +0100, Rohit kumar wrote: > > Remove no_pcm check to invoke pcm_new() for backend dai-links > too. This fixes crash in hdmi codec driver during hdmi_codec_startup() > while accessing chmap_info struct. chmap_info struct memory is > allocated in pcm_new() of hdmi codec driver which is not invoked > in case of DPCM when hdmi codec driver is part of backend dai-link. > > Below is the crash stack: > > [ 61.635493] Unable to handle kernel NULL pointer dereference at virtual address 00000018 > .. > [ 61.666696] CM = 0, WnR = 1 > [ 61.669778] user pgtable: 4k pages, 39-bit VAs, pgd = ffffffc0d6633000 > [ 61.676526] [0000000000000018] *pgd=0000000153fc8003, *pud=0000000153fc8003, *pmd=0000000000000000 > [ 61.685793] Internal error: Oops: 96000046 [#1] PREEMPT SMP > [ 61.722955] CPU: 7 PID: 2238 Comm: aplay Not tainted 4.14.72 #21 > .. > [ 61.740269] PC is at hdmi_codec_startup+0x124/0x164 > [ 61.745308] LR is at hdmi_codec_startup+0xe4/0x164 > > Signed-off-by: Rohit kumar Did you check whether all drivers have no side-effect by this change? The hdmi-codec isn't the only driver that has pcm_new ops, so we have to make sure that such a fundamental change wouldn't bring any regressions. thanks, Takashi