From patchwork Mon Nov 23 12:22:22 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 332329 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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, 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 4987BC64E7B for ; Mon, 23 Nov 2020 12:25:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E54D020781 for ; Mon, 23 Nov 2020 12:25:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Hu31+keg" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730032AbgKWMZl (ORCPT ); Mon, 23 Nov 2020 07:25:41 -0500 Received: from mail.kernel.org ([198.145.29.99]:35312 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730029AbgKWMZl (ORCPT ); Mon, 23 Nov 2020 07:25:41 -0500 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id DB70520857; Mon, 23 Nov 2020 12:25:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1606134340; bh=YoQDnUTsqVY+WKspD6+ZqPA26Klmis3QpVjN5O9GZjk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Hu31+kegdXVDR6AU4vE0AlCXWpASJjCepSzoTvVuzcTk1v9AyBCC4xzizK5D72Wu8 hFR1lL3V1uagM6hLXVTA3Gc7086/Wx+Pm8FNj3KHthBDxInwSl7zevj8MZAq9iHdkm ghqGJVqLpZNAPr8Gw7xvsrQGWvtRWtlLhqMpfkvY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dan Carpenter , Takashi Iwai Subject: [PATCH 4.9 36/47] ALSA: mixart: Fix mutex deadlock Date: Mon, 23 Nov 2020 13:22:22 +0100 Message-Id: <20201123121807.301191486@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201123121805.530891002@linuxfoundation.org> References: <20201123121805.530891002@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Takashi Iwai commit d21b96c8ed2aea7e6b7bf4735e1d2503cfbf4072 upstream. The code change for switching to non-atomic mode brought the unexpected mutex deadlock in get_msg(). It converted the spinlock with the existing mutex, but there were calls with the already holding the mutex. Since the only place that needs the extra lock is the code path from snd_mixart_send_msg(), remove the mutex lock in get_msg() and apply in the caller side for fixing the mutex deadlock. Fixes: 8d3a8b5cb57d ("ALSA: mixart: Use nonatomic PCM ops") Reported-by: Dan Carpenter Cc: Link: https://lore.kernel.org/r/20201119121440.18945-1-tiwai@suse.de Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman --- sound/pci/mixart/mixart_core.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) --- a/sound/pci/mixart/mixart_core.c +++ b/sound/pci/mixart/mixart_core.c @@ -83,7 +83,6 @@ static int get_msg(struct mixart_mgr *mg unsigned int i; #endif - mutex_lock(&mgr->msg_lock); err = 0; /* copy message descriptor from miXart to driver */ @@ -132,8 +131,6 @@ static int get_msg(struct mixart_mgr *mg writel_be(headptr, MIXART_MEM(mgr, MSG_OUTBOUND_FREE_HEAD)); _clean_exit: - mutex_unlock(&mgr->msg_lock); - return err; } @@ -271,7 +268,9 @@ int snd_mixart_send_msg(struct mixart_mg resp.data = resp_data; resp.size = max_resp_size; + mutex_lock(&mgr->msg_lock); err = get_msg(mgr, &resp, msg_frame); + mutex_unlock(&mgr->msg_lock); if( request->message_id != resp.message_id ) dev_err(&mgr->pci->dev, "RESPONSE ERROR!\n");