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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,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 AABB8C04AB1 for ; Mon, 13 May 2019 09:14:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8770D214AE for ; Mon, 13 May 2019 09:14:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728824AbfEMJOf (ORCPT ); Mon, 13 May 2019 05:14:35 -0400 Received: from mga06.intel.com ([134.134.136.31]:48372 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728718AbfEMJOd (ORCPT ); Mon, 13 May 2019 05:14:33 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 13 May 2019 02:14:32 -0700 X-ExtLoop1: 1 Received: from xxx.igk.intel.com ([10.237.93.170]) by fmsmga001.fm.intel.com with ESMTP; 13 May 2019 02:14:31 -0700 From: =?UTF-8?q?Amadeusz=20S=C5=82awi=C5=84ski?= To: alsa-devel@alsa-project.org Cc: Jaroslav Kysela , Takashi Iwai , linux-kernel@vger.kernel.org, =?UTF-8?q?Amadeusz=20S=C5=82awi=C5=84ski?= Subject: [PATCH v2] ALSA: hda: Fix race between creating and refreshing sysfs entries Date: Mon, 13 May 2019 11:18:01 +0200 Message-Id: <20190513091801.985-1-amadeuszx.slawinski@linux.intel.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org hda_widget_sysfs_reinit() can free underlying codec->widgets structure on which widget_tree_create() operates. Add locking to prevent such issues from happening. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=110382 Signed-off-by: Amadeusz Sławiński --- Changes since v1: - Moved mutexes around the callers - Added comments noting that functions should be called with mutex held --- include/sound/hdaudio.h | 1 + sound/hda/hdac_device.c | 7 +++++++ sound/hda/hdac_sysfs.c | 3 +++ 3 files changed, 11 insertions(+) diff --git a/include/sound/hdaudio.h b/include/sound/hdaudio.h index 45f944d57982..85835d0c33cc 100644 --- a/include/sound/hdaudio.h +++ b/include/sound/hdaudio.h @@ -81,6 +81,7 @@ struct hdac_device { atomic_t in_pm; /* suspend/resume being performed */ /* sysfs */ + struct mutex widget_lock; struct hdac_widget_tree *widgets; /* regmap */ diff --git a/sound/hda/hdac_device.c b/sound/hda/hdac_device.c index 95b073ee4b32..4769f4c03e14 100644 --- a/sound/hda/hdac_device.c +++ b/sound/hda/hdac_device.c @@ -55,6 +55,7 @@ int snd_hdac_device_init(struct hdac_device *codec, struct hdac_bus *bus, codec->bus = bus; codec->addr = addr; codec->type = HDA_DEV_CORE; + mutex_init(&codec->widget_lock); pm_runtime_set_active(&codec->dev); pm_runtime_get_noresume(&codec->dev); atomic_set(&codec->in_pm, 0); @@ -141,7 +142,9 @@ int snd_hdac_device_register(struct hdac_device *codec) err = device_add(&codec->dev); if (err < 0) return err; + mutex_lock(&codec->widget_lock); err = hda_widget_sysfs_init(codec); + mutex_unlock(&codec->widget_lock); if (err < 0) { device_del(&codec->dev); return err; @@ -158,7 +161,9 @@ EXPORT_SYMBOL_GPL(snd_hdac_device_register); void snd_hdac_device_unregister(struct hdac_device *codec) { if (device_is_registered(&codec->dev)) { + mutex_lock(&codec->widget_lock); hda_widget_sysfs_exit(codec); + mutex_unlock(&codec->widget_lock); device_del(&codec->dev); snd_hdac_bus_remove_device(codec->bus, codec); } @@ -404,7 +409,9 @@ int snd_hdac_refresh_widgets(struct hdac_device *codec, bool sysfs) } if (sysfs) { + mutex_lock(&codec->widget_lock); err = hda_widget_sysfs_reinit(codec, start_nid, nums); + mutex_unlock(&codec->widget_lock); if (err < 0) return err; } diff --git a/sound/hda/hdac_sysfs.c b/sound/hda/hdac_sysfs.c index fb2aa344981e..909d5ef1179c 100644 --- a/sound/hda/hdac_sysfs.c +++ b/sound/hda/hdac_sysfs.c @@ -395,6 +395,7 @@ static int widget_tree_create(struct hdac_device *codec) return 0; } +/* call with codec->widget_lock held */ int hda_widget_sysfs_init(struct hdac_device *codec) { int err; @@ -411,11 +412,13 @@ int hda_widget_sysfs_init(struct hdac_device *codec) return 0; } +/* call with codec->widget_lock held */ void hda_widget_sysfs_exit(struct hdac_device *codec) { widget_tree_free(codec); } +/* call with codec->widget_lock held */ int hda_widget_sysfs_reinit(struct hdac_device *codec, hda_nid_t start_nid, int num_nodes) { -- 2.17.1