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=-13.7 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FSL_HELO_FAKE,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_MUTT, USER_IN_DEF_DKIM_WL 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 97389C43219 for ; Mon, 29 Apr 2019 17:02:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 67A0D2087B for ; Mon, 29 Apr 2019 17:02:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="s2AGHwV0" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728695AbfD2RCX (ORCPT ); Mon, 29 Apr 2019 13:02:23 -0400 Received: from mail-it1-f194.google.com ([209.85.166.194]:54135 "EHLO mail-it1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728663AbfD2RCX (ORCPT ); Mon, 29 Apr 2019 13:02:23 -0400 Received: by mail-it1-f194.google.com with SMTP id z4so142795itc.3 for ; Mon, 29 Apr 2019 10:02:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=wL3BmO/NnA3NwafXMitsQjGpheHu4M8s6Xt8v0Jomo0=; b=s2AGHwV0MIipVuKm522AGWItowSBGgqT99tWc8KzjL140BVwLf0BNLJtwKT41jWXNL Ukof9nce0Cq6pB0k4RT6l+JJckq6LDo7dqUTee6F4HyesQwlrL6FccvupQpguUqjGpNE 1LBkfc1FShajkH5kEmAjl9yf5FfYh/FTohBDK2bup5Dt8ctFaMV91kmiluhGT6lwpsIL XNYRY1uDKflHGrH3ShCan7broKF2mwu9hB3Nri6Yuhib2DH1pqwGFDg425K6uze853HA YqRV8YWIdZh09HQ/zO2TrNYOfMHz1jkmWpxyVCVGrCB7tP4XVQzYSYBc/qRxDOruKlp+ OUKw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=wL3BmO/NnA3NwafXMitsQjGpheHu4M8s6Xt8v0Jomo0=; b=qUOWTy/9Wt30KNf6zQIJIRnUAG719pB9uLoC66UCGa9q4gr3OC/ThS9xqXN7Mxf4d4 KIu02XWoZVMetF9rBmtAn7m6upq3Roeql4G0FUFTUyktgphLGoJYL9JnWoCVLkKMXqhF qxAvzuiqH4K9f8OyaTKjeXECWKxIjtEbc9IrzKSDQLKNKXnZJHtFVLoW1fTdJKlIGAJ0 iOJvXk5yzf2RRpDERWhkuhZxUyoEJqQHL/15Ifv1P6gR31+Agi1Wz/2tSuAs7bPd4umq qgrfUoqx2X1QjgH8iB2WtqVv7QrVFEtppQ4NqOyGjUmPdJVp4WznAc8FjWHvBHuXIaOW f/nQ== X-Gm-Message-State: APjAAAUAgyxH57yODDATNK6qnky7+aadHggha6Mq9qvm+rLAIY+pE+Yn EA/Pd0Z3wgndGFSq59VU0lCs1w== X-Google-Smtp-Source: APXvYqyy2Hy85tx6UOgrLCUuzqKRridrK87+eM70gRZqlE4r2DrU+rLIsbBcQp9QFi70TYGENQj11w== X-Received: by 2002:a24:3602:: with SMTP id l2mr85415itl.68.1556557342335; Mon, 29 Apr 2019 10:02:22 -0700 (PDT) Received: from google.com ([2620:15c:183:200:855f:8919:84a7:4794]) by smtp.gmail.com with ESMTPSA id w2sm9289032iot.33.2019.04.29.10.02.21 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Mon, 29 Apr 2019 10:02:21 -0700 (PDT) Date: Mon, 29 Apr 2019 11:02:19 -0600 From: Ross Zwisler To: Pierre-Louis Bossart Cc: Ross Zwisler , linux-kernel@vger.kernel.org, Jaroslav Kysela , Jie Yang , Liam Girdwood , Mark Brown , Takashi Iwai , alsa-devel@alsa-project.org, stable@vger.kernel.org Subject: Re: [PATCH] ASoC: Intel: avoid Oops if DMA setup fails Message-ID: <20190429170219.GA89435@google.com> References: <20190426164740.211139-1-zwisler@google.com> <0b030b85-00c8-2e35-3064-bb764aaff0f6@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <0b030b85-00c8-2e35-3064-bb764aaff0f6@linux.intel.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Fri, Apr 26, 2019 at 04:03:47PM -0500, Pierre-Louis Bossart wrote: > On 4/26/19 11:47 AM, Ross Zwisler wrote: > > Currently in sst_dsp_new() if we get an error return from sst_dma_new() > > we just print an error message and then still complete the function > > successfully. This means that we are trying to run without sst->dma > > properly set up, which will result in NULL pointer dereference when > > sst->dma is later used. This was happening for me in > > sst_dsp_dma_get_channel(): > > > > struct sst_dma *dma = dsp->dma; > > ... > > dma->ch = dma_request_channel(mask, dma_chan_filter, dsp); > > > > This resulted in: > > > > BUG: unable to handle kernel NULL pointer dereference at 0000000000000018 > > IP: sst_dsp_dma_get_channel+0x4f/0x125 [snd_soc_sst_firmware] > > > > Fix this by adding proper error handling for the case where we fail to > > set up DMA. > > > > Signed-off-by: Ross Zwisler > > Cc: stable@vger.kernel.org > > --- > > sound/soc/intel/common/sst-firmware.c | 6 +++++- > > 1 file changed, 5 insertions(+), 1 deletion(-) > > > > diff --git a/sound/soc/intel/common/sst-firmware.c b/sound/soc/intel/common/sst-firmware.c > > index 1e067504b6043..9be3a793a55e3 100644 > > --- a/sound/soc/intel/common/sst-firmware.c > > +++ b/sound/soc/intel/common/sst-firmware.c > > @@ -1251,11 +1251,15 @@ struct sst_dsp *sst_dsp_new(struct device *dev, > > goto irq_err; > > err = sst_dma_new(sst); > > - if (err) > > + if (err) { > > dev_warn(dev, "sst_dma_new failed %d\n", err); > > + goto dma_err; > > + } > > Thanks for the patch. > The fix looks correct, but does it make sense to keep a dev_warn() here? > Should it be changed to dev_err() instead since as you mentioned it's fatal > to keep going. > Also you may want to mention in the commit message that this should only > impact Broadwell and maybe the legacy Baytrail driver. IIRC we don't use the > DMAs in other cases. Sure, I'll address both of these in a v2. Thank you for the quick review.