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=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, 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 5EA87C43219 for ; Thu, 16 Sep 2021 17:52:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4ADD66113A for ; Thu, 16 Sep 2021 17:52:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1357327AbhIPRvi (ORCPT ); Thu, 16 Sep 2021 13:51:38 -0400 Received: from mail.kernel.org ([198.145.29.99]:53744 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1354331AbhIPRjn (ORCPT ); Thu, 16 Sep 2021 13:39:43 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id BF66063253; Thu, 16 Sep 2021 16:50:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1631811043; bh=6+MONF8EmtdpRsVvsw+V+vRmiKz8kfaaA31jO5pe8sg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=2n967IMJzmwkIrPoBq24VdhAVXkvtk4+uA4pHHSFfqiryfQ3FhosN75QrcfNifszz FwYt3J/tEnZ/i4UJafvBYd008WreRtiJx+abqx2gGZ3aU8GZW+is8hkDmXCiPP7zAm sRYxzSTOUMNAchpipFswwEw8MGVzCUtN5PQX4RlE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Pierre-Louis Bossart , Mark Brown , Sasha Levin Subject: [PATCH 5.14 362/432] ASoC: soc-pcm: protect BE dailink state changes in trigger Date: Thu, 16 Sep 2021 18:01:51 +0200 Message-Id: <20210916155823.081267083@linuxfoundation.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210916155810.813340753@linuxfoundation.org> References: <20210916155810.813340753@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Pierre-Louis Bossart [ Upstream commit 0c75fc7193387776c10f7c7b440d93496e3d5e21 ] When more than one FE is connected to a BE, e.g. in a mixing use case, the BE can be triggered multiple times when the FE are opened/started concurrently. This race condition is problematic in the case of SoundWire BE dailinks, and this is not desirable in a general case. The code carefully checks when the BE can be stopped or hw_free'ed, but the trigger code does not use any mutual exclusion. Fix by using the same spinlock already used to check FE states, and set the state before the trigger. In case of errors, the initial state will be restored. This patch does not change how the triggers are handled, it only makes sure the states are handled in critical sections. Signed-off-by: Pierre-Louis Bossart Message-Id: <20210817164054.250028-2-pierre-louis.bossart@linux.intel.com> Signed-off-by: Mark Brown Signed-off-by: Sasha Levin --- sound/soc/soc-pcm.c | 103 ++++++++++++++++++++++++++++++++++++-------- 1 file changed, 85 insertions(+), 18 deletions(-) diff --git a/sound/soc/soc-pcm.c b/sound/soc/soc-pcm.c index d1c570ca21ea..b944f56a469a 100644 --- a/sound/soc/soc-pcm.c +++ b/sound/soc/soc-pcm.c @@ -2001,6 +2001,8 @@ int dpcm_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream, struct snd_soc_pcm_runtime *be; struct snd_soc_dpcm *dpcm; int ret = 0; + unsigned long flags; + enum snd_soc_dpcm_state state; for_each_dpcm_be(fe, stream, dpcm) { struct snd_pcm_substream *be_substream; @@ -2017,76 +2019,141 @@ int dpcm_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream, switch (cmd) { case SNDRV_PCM_TRIGGER_START: + spin_lock_irqsave(&fe->card->dpcm_lock, flags); if ((be->dpcm[stream].state != SND_SOC_DPCM_STATE_PREPARE) && (be->dpcm[stream].state != SND_SOC_DPCM_STATE_STOP) && - (be->dpcm[stream].state != SND_SOC_DPCM_STATE_PAUSED)) + (be->dpcm[stream].state != SND_SOC_DPCM_STATE_PAUSED)) { + spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); continue; + } + state = be->dpcm[stream].state; + be->dpcm[stream].state = SND_SOC_DPCM_STATE_START; + spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); ret = soc_pcm_trigger(be_substream, cmd); - if (ret) + if (ret) { + spin_lock_irqsave(&fe->card->dpcm_lock, flags); + be->dpcm[stream].state = state; + spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); goto end; + } - be->dpcm[stream].state = SND_SOC_DPCM_STATE_START; break; case SNDRV_PCM_TRIGGER_RESUME: - if ((be->dpcm[stream].state != SND_SOC_DPCM_STATE_SUSPEND)) + spin_lock_irqsave(&fe->card->dpcm_lock, flags); + if (be->dpcm[stream].state != SND_SOC_DPCM_STATE_SUSPEND) { + spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); continue; + } + + state = be->dpcm[stream].state; + be->dpcm[stream].state = SND_SOC_DPCM_STATE_START; + spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); ret = soc_pcm_trigger(be_substream, cmd); - if (ret) + if (ret) { + spin_lock_irqsave(&fe->card->dpcm_lock, flags); + be->dpcm[stream].state = state; + spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); goto end; + } - be->dpcm[stream].state = SND_SOC_DPCM_STATE_START; break; case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: - if ((be->dpcm[stream].state != SND_SOC_DPCM_STATE_PAUSED)) + spin_lock_irqsave(&fe->card->dpcm_lock, flags); + if (be->dpcm[stream].state != SND_SOC_DPCM_STATE_PAUSED) { + spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); continue; + } + + state = be->dpcm[stream].state; + be->dpcm[stream].state = SND_SOC_DPCM_STATE_START; + spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); ret = soc_pcm_trigger(be_substream, cmd); - if (ret) + if (ret) { + spin_lock_irqsave(&fe->card->dpcm_lock, flags); + be->dpcm[stream].state = state; + spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); goto end; + } - be->dpcm[stream].state = SND_SOC_DPCM_STATE_START; break; case SNDRV_PCM_TRIGGER_STOP: + spin_lock_irqsave(&fe->card->dpcm_lock, flags); if ((be->dpcm[stream].state != SND_SOC_DPCM_STATE_START) && - (be->dpcm[stream].state != SND_SOC_DPCM_STATE_PAUSED)) + (be->dpcm[stream].state != SND_SOC_DPCM_STATE_PAUSED)) { + spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); continue; + } + spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); if (!snd_soc_dpcm_can_be_free_stop(fe, be, stream)) continue; + spin_lock_irqsave(&fe->card->dpcm_lock, flags); + state = be->dpcm[stream].state; + be->dpcm[stream].state = SND_SOC_DPCM_STATE_STOP; + spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); + ret = soc_pcm_trigger(be_substream, cmd); - if (ret) + if (ret) { + spin_lock_irqsave(&fe->card->dpcm_lock, flags); + be->dpcm[stream].state = state; + spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); goto end; + } - be->dpcm[stream].state = SND_SOC_DPCM_STATE_STOP; break; case SNDRV_PCM_TRIGGER_SUSPEND: - if (be->dpcm[stream].state != SND_SOC_DPCM_STATE_START) + spin_lock_irqsave(&fe->card->dpcm_lock, flags); + if (be->dpcm[stream].state != SND_SOC_DPCM_STATE_START) { + spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); continue; + } + spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); if (!snd_soc_dpcm_can_be_free_stop(fe, be, stream)) continue; + spin_lock_irqsave(&fe->card->dpcm_lock, flags); + state = be->dpcm[stream].state; + be->dpcm[stream].state = SND_SOC_DPCM_STATE_STOP; + spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); + ret = soc_pcm_trigger(be_substream, cmd); - if (ret) + if (ret) { + spin_lock_irqsave(&fe->card->dpcm_lock, flags); + be->dpcm[stream].state = state; + spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); goto end; + } - be->dpcm[stream].state = SND_SOC_DPCM_STATE_SUSPEND; break; case SNDRV_PCM_TRIGGER_PAUSE_PUSH: - if (be->dpcm[stream].state != SND_SOC_DPCM_STATE_START) + spin_lock_irqsave(&fe->card->dpcm_lock, flags); + if (be->dpcm[stream].state != SND_SOC_DPCM_STATE_START) { + spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); continue; + } + spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); if (!snd_soc_dpcm_can_be_free_stop(fe, be, stream)) continue; + spin_lock_irqsave(&fe->card->dpcm_lock, flags); + state = be->dpcm[stream].state; + be->dpcm[stream].state = SND_SOC_DPCM_STATE_PAUSED; + spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); + ret = soc_pcm_trigger(be_substream, cmd); - if (ret) + if (ret) { + spin_lock_irqsave(&fe->card->dpcm_lock, flags); + be->dpcm[stream].state = state; + spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); goto end; + } - be->dpcm[stream].state = SND_SOC_DPCM_STATE_PAUSED; break; } } -- 2.30.2