From patchwork Wed Dec 2 17:24:46 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Hellstrom X-Patchwork-Id: 7749721 Return-Path: X-Original-To: patchwork-dri-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id F2F379F350 for ; Wed, 2 Dec 2015 17:25:21 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 03B4B204E3 for ; Wed, 2 Dec 2015 17:25:21 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by mail.kernel.org (Postfix) with ESMTP id 3C52F204C9 for ; Wed, 2 Dec 2015 17:25:19 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id DE84E6EA58; Wed, 2 Dec 2015 09:25:17 -0800 (PST) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from smtp-outbound-2.vmware.com (smtp-outbound-2.vmware.com [208.91.2.13]) by gabe.freedesktop.org (Postfix) with ESMTPS id 15B8C6EA1C for ; Wed, 2 Dec 2015 09:25:16 -0800 (PST) Received: from sc9-mailhost3.vmware.com (sc9-mailhost3.vmware.com [10.113.161.73]) by smtp-outbound-2.vmware.com (Postfix) with ESMTP id 6A4E228BBC; Wed, 2 Dec 2015 09:25:14 -0800 (PST) Received: from EX13-CAS-004.vmware.com (ex13-cas-004.vmware.com [10.113.191.54]) by sc9-mailhost3.vmware.com (Postfix) with ESMTP id 2A43040671; Wed, 2 Dec 2015 09:25:15 -0800 (PST) Received: from ubuntu.localdomain (10.113.170.11) by EX13-MBX-024.vmware.com (10.113.191.44) with Microsoft SMTP Server (TLS) id 15.0.1076.9; Wed, 2 Dec 2015 09:25:12 -0800 From: Thomas Hellstrom To: , Subject: [PATCH] drm: Fix an unwanted master inheritance v2 Date: Wed, 2 Dec 2015 09:24:46 -0800 Message-ID: <1449077086-3125-1-git-send-email-thellstrom@vmware.com> X-Mailer: git-send-email 2.1.0 MIME-Version: 1.0 X-Originating-IP: [10.113.170.11] X-ClientProxiedBy: EX13-CAS-013.vmware.com (10.113.191.65) To EX13-MBX-024.vmware.com (10.113.191.44) Cc: pv-drivers@vmware.com, Thomas Hellstrom , stable@vger.kernel.org X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP A client calling drmSetMaster() using a file descriptor that was opened when another client was master would inherit the latter client's master object and all its authenticated clients. This is unwanted behaviour, and when this happens, instead allocate a brand new master object for the client calling drmSetMaster(). Fixes a BUG() throw in vmw_master_set(). Cc: Signed-off-by: Thomas Hellstrom Reviewed-by: Emil Velikov --- drivers/gpu/drm/drm_drv.c | 5 +++ drivers/gpu/drm/drm_fops.c | 84 ++++++++++++++++++++++++++++++---------------- include/drm/drmP.h | 6 ++++ 3 files changed, 67 insertions(+), 28 deletions(-) diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c index 9362609..7dd6728 100644 --- a/drivers/gpu/drm/drm_drv.c +++ b/drivers/gpu/drm/drm_drv.c @@ -160,6 +160,11 @@ int drm_setmaster_ioctl(struct drm_device *dev, void *data, goto out_unlock; } + if (!file_priv->allowed_master) { + ret = drm_new_set_master(dev, file_priv); + goto out_unlock; + } + file_priv->minor->master = drm_master_get(file_priv->master); file_priv->is_master = 1; if (dev->driver->master_set) { diff --git a/drivers/gpu/drm/drm_fops.c b/drivers/gpu/drm/drm_fops.c index c59ce4d..6b5625e 100644 --- a/drivers/gpu/drm/drm_fops.c +++ b/drivers/gpu/drm/drm_fops.c @@ -126,6 +126,60 @@ static int drm_cpu_valid(void) } /** + * drm_new_set_master - Allocate a new master object and become master for the + * associated master realm. + * + * @dev: The associated device. + * @fpriv: File private identifying the client. + * + * This function must be called with dev::struct_mutex held. + * Returns negative error code on failure. Zero on success. + */ +int drm_new_set_master(struct drm_device *dev, struct drm_file *fpriv) +{ + struct drm_master *old_master; + int ret; + + lockdep_assert_held_once(&dev->master_mutex); + + /* create a new master */ + fpriv->minor->master = drm_master_create(fpriv->minor); + if (!fpriv->minor->master) + return -ENOMEM; + + /* take another reference for the copy in the local file priv */ + old_master = fpriv->master; + fpriv->master = drm_master_get(fpriv->minor->master); + + if (dev->driver->master_create) { + ret = dev->driver->master_create(dev, fpriv->master); + if (ret) + goto out_err; + } + if (dev->driver->master_set) { + ret = dev->driver->master_set(dev, fpriv, true); + if (ret) + goto out_err; + } + + fpriv->is_master = 1; + fpriv->allowed_master = 1; + fpriv->authenticated = 1; + if (old_master) + drm_master_put(&old_master); + + return 0; + +out_err: + /* drop both references and restore old master on failure */ + drm_master_put(&fpriv->minor->master); + drm_master_put(&fpriv->master); + fpriv->master = old_master; + + return ret; +} + +/** * Called whenever a process opens /dev/drm. * * \param filp file pointer. @@ -189,35 +243,9 @@ static int drm_open_helper(struct file *filp, struct drm_minor *minor) mutex_lock(&dev->master_mutex); if (drm_is_primary_client(priv) && !priv->minor->master) { /* create a new master */ - priv->minor->master = drm_master_create(priv->minor); - if (!priv->minor->master) { - ret = -ENOMEM; + ret = drm_new_set_master(dev, priv); + if (ret) goto out_close; - } - - priv->is_master = 1; - /* take another reference for the copy in the local file priv */ - priv->master = drm_master_get(priv->minor->master); - priv->authenticated = 1; - - if (dev->driver->master_create) { - ret = dev->driver->master_create(dev, priv->master); - if (ret) { - /* drop both references if this fails */ - drm_master_put(&priv->minor->master); - drm_master_put(&priv->master); - goto out_close; - } - } - if (dev->driver->master_set) { - ret = dev->driver->master_set(dev, priv, true); - if (ret) { - /* drop both references if this fails */ - drm_master_put(&priv->minor->master); - drm_master_put(&priv->master); - goto out_close; - } - } } else if (drm_is_primary_client(priv)) { /* get a reference to the master */ priv->master = drm_master_get(priv->minor->master); diff --git a/include/drm/drmP.h b/include/drm/drmP.h index 0b921ae..441b26e 100644 --- a/include/drm/drmP.h +++ b/include/drm/drmP.h @@ -309,6 +309,11 @@ struct drm_file { unsigned universal_planes:1; /* true if client understands atomic properties */ unsigned atomic:1; + /* + * This client is allowed to gain master privileges for @master. + * Protected by struct drm_device::master_mutex. + */ + unsigned allowed_master:1; struct pid *pid; kuid_t uid; @@ -910,6 +915,7 @@ extern int drm_open(struct inode *inode, struct file *filp); extern ssize_t drm_read(struct file *filp, char __user *buffer, size_t count, loff_t *offset); extern int drm_release(struct inode *inode, struct file *filp); +extern int drm_new_set_master(struct drm_device *dev, struct drm_file *fpriv); /* Mapping support (drm_vm.h) */ extern unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait);