Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756081AbcK2CPj (ORCPT ); Mon, 28 Nov 2016 21:15:39 -0500 Received: from ec2-52-27-115-49.us-west-2.compute.amazonaws.com ([52.27.115.49]:42873 "EHLO osg.samsung.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1756030AbcK2CPY (ORCPT ); Mon, 28 Nov 2016 21:15:24 -0500 X-Amavis-Alert: BAD HEADER SECTION, Duplicate header field: "References" From: Shuah Khan To: mchehab@kernel.org, mkrufky@linuxtv.org, klock.android@gmail.com, elfring@users.sourceforge.net, max@duempel.org, hans.verkuil@cisco.com, javier@osg.samsung.com, chehabrafael@gmail.com, sakari.ailus@linux.intel.com, laurent.pinchart+renesas@ideasonboard.com Cc: Shuah Khan , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 2/2] media: protect enable and disable source handler checks and calls Date: Mon, 28 Nov 2016 19:15:14 -0700 Message-Id: <54975937478803ef4883e9caecb8af0ef282e35c.1480384155.git.shuahkh@osg.samsung.com> X-Mailer: git-send-email 2.9.3 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5848 Lines: 184 Protect enable and disable source handler checks and calls from dvb-core and v4l2-core. Hold graph_mutex to check if enable and disable source handlers are present and invoke them while holding the mutex. This change ensures these handlers will not be removed while they are being checked and invoked. au08282 enable and disable source handlers are changed to not hold the graph_mutex. Signed-off-by: Shuah Khan --- drivers/media/dvb-core/dvb_frontend.c | 24 ++++++++++++++++++------ drivers/media/usb/au0828/au0828-core.c | 17 +++++------------ drivers/media/v4l2-core/v4l2-mc.c | 26 ++++++++++++++++++-------- 3 files changed, 41 insertions(+), 26 deletions(-) diff --git a/drivers/media/dvb-core/dvb_frontend.c b/drivers/media/dvb-core/dvb_frontend.c index 01511e5..2f09c7e 100644 --- a/drivers/media/dvb-core/dvb_frontend.c +++ b/drivers/media/dvb-core/dvb_frontend.c @@ -2527,9 +2527,13 @@ static int dvb_frontend_open(struct inode *inode, struct file *file) fepriv->voltage = -1; #ifdef CONFIG_MEDIA_CONTROLLER_DVB - if (fe->dvb->mdev && fe->dvb->mdev->enable_source) { - ret = fe->dvb->mdev->enable_source(dvbdev->entity, + if (fe->dvb->mdev) { + mutex_lock(&fe->dvb->mdev->graph_mutex); + if (fe->dvb->mdev->enable_source) + ret = fe->dvb->mdev->enable_source( + dvbdev->entity, &fepriv->pipe); + mutex_unlock(&fe->dvb->mdev->graph_mutex); if (ret) { dev_err(fe->dvb->device, "Tuner is busy. Error %d\n", ret); @@ -2553,8 +2557,12 @@ static int dvb_frontend_open(struct inode *inode, struct file *file) err3: #ifdef CONFIG_MEDIA_CONTROLLER_DVB - if (fe->dvb->mdev && fe->dvb->mdev->disable_source) - fe->dvb->mdev->disable_source(dvbdev->entity); + if (fe->dvb->mdev) { + mutex_lock(&fe->dvb->mdev->graph_mutex); + if (fe->dvb->mdev->disable_source) + fe->dvb->mdev->disable_source(dvbdev->entity); + mutex_unlock(&fe->dvb->mdev->graph_mutex); + } err2: #endif dvb_generic_release(inode, file); @@ -2586,8 +2594,12 @@ static int dvb_frontend_release(struct inode *inode, struct file *file) if (dvbdev->users == -1) { wake_up(&fepriv->wait_queue); #ifdef CONFIG_MEDIA_CONTROLLER_DVB - if (fe->dvb->mdev && fe->dvb->mdev->disable_source) - fe->dvb->mdev->disable_source(dvbdev->entity); + if (fe->dvb->mdev) { + mutex_lock(&fe->dvb->mdev->graph_mutex); + if (fe->dvb->mdev->disable_source) + fe->dvb->mdev->disable_source(dvbdev->entity); + mutex_unlock(&fe->dvb->mdev->graph_mutex); + } #endif if (fe->exit != DVB_FE_NO_EXIT) wake_up(&dvbdev->wait_queue); diff --git a/drivers/media/usb/au0828/au0828-core.c b/drivers/media/usb/au0828/au0828-core.c index a1f696a..bfd6482 100644 --- a/drivers/media/usb/au0828/au0828-core.c +++ b/drivers/media/usb/au0828/au0828-core.c @@ -280,6 +280,7 @@ static void au0828_media_graph_notify(struct media_entity *new, } } +/* Callers should hold graph_mutex */ static int au0828_enable_source(struct media_entity *entity, struct media_pipeline *pipe) { @@ -293,8 +294,6 @@ static int au0828_enable_source(struct media_entity *entity, if (!mdev) return -ENODEV; - mutex_lock(&mdev->graph_mutex); - dev = mdev->source_priv; /* @@ -421,12 +420,12 @@ static int au0828_enable_source(struct media_entity *entity, dev->active_source->name, dev->active_sink->name, dev->active_link_owner->name, ret); end: - mutex_unlock(&mdev->graph_mutex); pr_debug("au0828_enable_source() end %s %d %d\n", entity->name, entity->function, ret); return ret; } +/* Callers should hold graph_mutex */ static void au0828_disable_source(struct media_entity *entity) { int ret = 0; @@ -436,13 +435,10 @@ static void au0828_disable_source(struct media_entity *entity) if (!mdev) return; - mutex_lock(&mdev->graph_mutex); dev = mdev->source_priv; - if (!dev->active_link) { - ret = -ENODEV; - goto end; - } + if (!dev->active_link) + return; /* link is active - stop pipeline from source (tuner) */ if (dev->active_link->sink->entity == dev->active_sink && @@ -452,7 +448,7 @@ static void au0828_disable_source(struct media_entity *entity) * has active pipeline */ if (dev->active_link_owner != entity) - goto end; + return; __media_entity_pipeline_stop(entity); ret = __media_entity_setup_link(dev->active_link, 0); if (ret) @@ -467,9 +463,6 @@ static void au0828_disable_source(struct media_entity *entity) dev->active_source = NULL; dev->active_sink = NULL; } - -end: - mutex_unlock(&mdev->graph_mutex); } #endif diff --git a/drivers/media/v4l2-core/v4l2-mc.c b/drivers/media/v4l2-core/v4l2-mc.c index 8bef433..b169d24 100644 --- a/drivers/media/v4l2-core/v4l2-mc.c +++ b/drivers/media/v4l2-core/v4l2-mc.c @@ -198,14 +198,20 @@ EXPORT_SYMBOL_GPL(v4l2_mc_create_media_graph); int v4l_enable_media_source(struct video_device *vdev) { struct media_device *mdev = vdev->entity.graph_obj.mdev; - int ret; + int ret = 0, err; - if (!mdev || !mdev->enable_source) + if (!mdev) return 0; - ret = mdev->enable_source(&vdev->entity, &vdev->pipe); - if (ret) - return -EBUSY; - return 0; + + mutex_lock(&mdev->graph_mutex); + if (!mdev->enable_source) + goto end; + err = mdev->enable_source(&vdev->entity, &vdev->pipe); + if (err) + ret = -EBUSY; +end: + mutex_unlock(&mdev->graph_mutex); + return ret; } EXPORT_SYMBOL_GPL(v4l_enable_media_source); @@ -213,8 +219,12 @@ void v4l_disable_media_source(struct video_device *vdev) { struct media_device *mdev = vdev->entity.graph_obj.mdev; - if (mdev && mdev->disable_source) - mdev->disable_source(&vdev->entity); + if (mdev) { + mutex_lock(&mdev->graph_mutex); + if (mdev->disable_source) + mdev->disable_source(&vdev->entity); + mutex_unlock(&mdev->graph_mutex); + } } EXPORT_SYMBOL_GPL(v4l_disable_media_source); -- 2.7.4