From patchwork Mon Nov 23 12:22:30 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 332080 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=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 E9EB1C8300C for ; Mon, 23 Nov 2020 13:25:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7FDBE2075A for ; Mon, 23 Nov 2020 13:25:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="0ksHPche" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731253AbgKWMdk (ORCPT ); Mon, 23 Nov 2020 07:33:40 -0500 Received: from mail.kernel.org ([198.145.29.99]:44958 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731244AbgKWMdh (ORCPT ); Mon, 23 Nov 2020 07:33:37 -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 E96A320721; Mon, 23 Nov 2020 12:33:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1606134816; bh=YoQDnUTsqVY+WKspD6+ZqPA26Klmis3QpVjN5O9GZjk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0ksHPcheyuBYaYosHiKznGlGizn8WFqy5SxI1P2rPdhfL048raqZWzUjhdUeDYB3D KO1glFF1KayKc9VAyLpybxVrjjwrDDMjNDHT+kCZJnsKD2toW9jIrI+BUrMouiW+gD vFvSkdfK5a3JL+9/Dsn0BVJBitw94dePaXXuOMoE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dan Carpenter , Takashi Iwai Subject: [PATCH 4.19 70/91] ALSA: mixart: Fix mutex deadlock Date: Mon, 23 Nov 2020 13:22:30 +0100 Message-Id: <20201123121812.727253198@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201123121809.285416732@linuxfoundation.org> References: <20201123121809.285416732@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");