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=-17.0 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 C6154C433F5 for ; Thu, 9 Sep 2021 11:46:41 +0000 (UTC) Received: from alsa0.perex.cz (alsa0.perex.cz [77.48.224.243]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E478961242 for ; Thu, 9 Sep 2021 11:46:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org E478961242 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=alsa-project.org Received: from alsa1.perex.cz (alsa1.perex.cz [207.180.221.201]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by alsa0.perex.cz (Postfix) with ESMTPS id 6B13216AC; Thu, 9 Sep 2021 13:45:49 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz 6B13216AC DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1631187999; bh=v8vGB+3mWBq+luhinJRW757yoV4KKwTtTnholGUTLsE=; h=From:To:Subject:Date:In-Reply-To:References:Cc:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From; b=scndWsAtTTyGVOgM+OShTM9NauBnEtjc+YnpMJobTjBPWZ2iQR4PdBNg7/Oc5Ku+T hRr815SJoe8L/LKBbVN9pT5zI8zCUZQO/ax9vZXKNydlwXj/0ANmq0rmMNbSQr7k1/ yI8vbOCWhIQy6wOWqjCKOEaAmqSneySPjmUe/Mbw= Received: from alsa1.perex.cz (localhost.localdomain [127.0.0.1]) by alsa1.perex.cz (Postfix) with ESMTP id 4962CF804B2; Thu, 9 Sep 2021 13:45:36 +0200 (CEST) Received: by alsa1.perex.cz (Postfix, from userid 50401) id D33ACF804E7; Thu, 9 Sep 2021 13:45:34 +0200 (CEST) Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by alsa1.perex.cz (Postfix) with ESMTPS id 56855F80300 for ; Thu, 9 Sep 2021 13:45:28 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz 56855F80300 Authentication-Results: alsa1.perex.cz; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="VbKscrxZ" Received: by mail.kernel.org (Postfix) with ESMTPSA id 24E3F61216; Thu, 9 Sep 2021 11:45:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631187926; bh=v8vGB+3mWBq+luhinJRW757yoV4KKwTtTnholGUTLsE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VbKscrxZlvRZCzjJ+Ie5IqlrKKn1T3+PwpCt4617zEhBP1MykaEEWBy+hurgjOQih AwNKAL8Inwz0T8UOr032mhe5lrxX/l5W/8SQ8HiGX0NCNtc/WZtrRnZlqlL5Nj1ECS 5qbUfU/HcB0DhbdXZTs4uL31BwT94SWtf2UswmU7vnJq1vv30ZuiIkWJoEyx1ayabj uxjHYKOSmLD/434djfbsRBx/R/m6sAqDAgIlvXA8DJ2TldkA27RYoXAXccqUloaKNK XJVMkYSOohDO6qQ66b60APYi3U6i7V+S140NqI2n1lu9mX98DtPLADw6nkyyRTUaS+ RIJCZeVUid19Q== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH AUTOSEL 5.14 199/252] soundwire: intel: fix potential race condition during power down Date: Thu, 9 Sep 2021 07:40:13 -0400 Message-Id: <20210909114106.141462-199-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210909114106.141462-1-sashal@kernel.org> References: <20210909114106.141462-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Cc: Sasha Levin , alsa-devel@alsa-project.org, Pierre-Louis Bossart , Ranjani Sridharan , Vinod Koul , Bard Liao X-BeenThere: alsa-devel@alsa-project.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: "Alsa-devel mailing list for ALSA developers - http://www.alsa-project.org" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: "Alsa-devel" From: Pierre-Louis Bossart [ Upstream commit ea6942dad4b2a7e1735aa0f10f3d0b04b847750f ] The power down sequence sets the link_up flag as false outside of the mutex_lock. This is potentially unsafe. In additional the flow in that sequence can be improved by first testing if the link was powered, setting the link_up flag as false and proceeding with the power down. In case the CPA bits cannot be cleared, we only flag an error since we cannot deal with interrupts any longer. Signed-off-by: Pierre-Louis Bossart Reviewed-by: Ranjani Sridharan Signed-off-by: Bard Liao Link: https://lore.kernel.org/r/20210818024954.16873-2-yung-chuan.liao@linux.intel.com Signed-off-by: Vinod Koul Signed-off-by: Sasha Levin --- drivers/soundwire/intel.c | 23 +++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-) diff --git a/drivers/soundwire/intel.c b/drivers/soundwire/intel.c index c11e3d8cd308..f156de765c68 100644 --- a/drivers/soundwire/intel.c +++ b/drivers/soundwire/intel.c @@ -537,12 +537,14 @@ static int intel_link_power_down(struct sdw_intel *sdw) mutex_lock(sdw->link_res->shim_lock); - intel_shim_master_ip_to_glue(sdw); - if (!(*shim_mask & BIT(link_id))) dev_err(sdw->cdns.dev, "%s: Unbalanced power-up/down calls\n", __func__); + sdw->cdns.link_up = false; + + intel_shim_master_ip_to_glue(sdw); + *shim_mask &= ~BIT(link_id); if (!*shim_mask) { @@ -559,18 +561,19 @@ static int intel_link_power_down(struct sdw_intel *sdw) link_control &= spa_mask; ret = intel_clear_bit(shim, SDW_SHIM_LCTL, link_control, cpa_mask); + if (ret < 0) { + dev_err(sdw->cdns.dev, "%s: could not power down link\n", __func__); + + /* + * we leave the sdw->cdns.link_up flag as false since we've disabled + * the link at this point and cannot handle interrupts any longer. + */ + } } mutex_unlock(sdw->link_res->shim_lock); - if (ret < 0) { - dev_err(sdw->cdns.dev, "%s: could not power down link\n", __func__); - - return ret; - } - - sdw->cdns.link_up = false; - return 0; + return ret; } static void intel_shim_sync_arm(struct sdw_intel *sdw) -- 2.30.2