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=-5.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,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 36F31C004D2 for ; Tue, 2 Oct 2018 13:28:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 02E622089A for ; Tue, 2 Oct 2018 13:28:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 02E622089A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729077AbeJBULa (ORCPT ); Tue, 2 Oct 2018 16:11:30 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:60726 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729045AbeJBUL2 (ORCPT ); Tue, 2 Oct 2018 16:11:28 -0400 Received: from localhost (24-104-73-23-ip-static.hfc.comcastbusiness.net [24.104.73.23]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id A9643C4D; Tue, 2 Oct 2018 13:28:06 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Daniel Vetter , Tomi Valkeinen , Laurent Pinchart , Sasha Levin Subject: [PATCH 4.18 093/228] drm/omap: gem: Fix mm_list locking Date: Tue, 2 Oct 2018 06:23:10 -0700 Message-Id: <20181002132505.637714377@linuxfoundation.org> X-Mailer: git-send-email 2.19.0 In-Reply-To: <20181002132459.032960735@linuxfoundation.org> References: <20181002132459.032960735@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review 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 4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Daniel Vetter [ Upstream commit 5117bd898e8c0a31e8ab3a9b8523aecf0706e997 ] - None of the list walkings where protected. - Switch to a mutex since the list walking at device resume time can sleep when pinning buffers through the tiler. Only thing we need to be careful with here is that while we walk the list we can't unreference any gem objects, since the final unref would result in a recursive deadlock. But the only functions that walk the list is the device resume and debugfs dumping, so all safe. Signed-off-by: Daniel Vetter Reviewed-by: Tomi Valkeinen Reviewed-by: Laurent Pinchart Signed-off-by: Laurent Pinchart Signed-off-by: Tomi Valkeinen Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/omapdrm/omap_debugfs.c | 2 ++ drivers/gpu/drm/omapdrm/omap_drv.c | 2 +- drivers/gpu/drm/omapdrm/omap_drv.h | 2 +- drivers/gpu/drm/omapdrm/omap_gem.c | 15 +++++++++------ 4 files changed, 13 insertions(+), 8 deletions(-) --- a/drivers/gpu/drm/omapdrm/omap_debugfs.c +++ b/drivers/gpu/drm/omapdrm/omap_debugfs.c @@ -37,7 +37,9 @@ static int gem_show(struct seq_file *m, return ret; seq_printf(m, "All Objects:\n"); + mutex_lock(&priv->list_lock); omap_gem_describe_objects(&priv->obj_list, m); + mutex_unlock(&priv->list_lock); mutex_unlock(&dev->struct_mutex); --- a/drivers/gpu/drm/omapdrm/omap_drv.c +++ b/drivers/gpu/drm/omapdrm/omap_drv.c @@ -540,7 +540,7 @@ static int omapdrm_init(struct omap_drm_ priv->omaprev = soc ? (unsigned int)soc->data : 0; priv->wq = alloc_ordered_workqueue("omapdrm", 0); - spin_lock_init(&priv->list_lock); + mutex_init(&priv->list_lock); INIT_LIST_HEAD(&priv->obj_list); /* Allocate and initialize the DRM device. */ --- a/drivers/gpu/drm/omapdrm/omap_drv.h +++ b/drivers/gpu/drm/omapdrm/omap_drv.h @@ -71,7 +71,7 @@ struct omap_drm_private { struct workqueue_struct *wq; /* lock for obj_list below */ - spinlock_t list_lock; + struct mutex list_lock; /* list of GEM objects: */ struct list_head obj_list; --- a/drivers/gpu/drm/omapdrm/omap_gem.c +++ b/drivers/gpu/drm/omapdrm/omap_gem.c @@ -1001,6 +1001,7 @@ int omap_gem_resume(struct drm_device *d struct omap_gem_object *omap_obj; int ret = 0; + mutex_lock(&priv->list_lock); list_for_each_entry(omap_obj, &priv->obj_list, mm_list) { if (omap_obj->block) { struct drm_gem_object *obj = &omap_obj->base; @@ -1012,12 +1013,14 @@ int omap_gem_resume(struct drm_device *d omap_obj->roll, true); if (ret) { dev_err(dev->dev, "could not repin: %d\n", ret); - return ret; + goto done; } } } - return 0; +done: + mutex_unlock(&priv->list_lock); + return ret; } #endif @@ -1085,9 +1088,9 @@ void omap_gem_free_object(struct drm_gem WARN_ON(!mutex_is_locked(&dev->struct_mutex)); - spin_lock(&priv->list_lock); + mutex_lock(&priv->list_lock); list_del(&omap_obj->mm_list); - spin_unlock(&priv->list_lock); + mutex_unlock(&priv->list_lock); /* this means the object is still pinned.. which really should * not happen. I think.. @@ -1206,9 +1209,9 @@ struct drm_gem_object *omap_gem_new(stru goto err_release; } - spin_lock(&priv->list_lock); + mutex_lock(&priv->list_lock); list_add(&omap_obj->mm_list, &priv->obj_list); - spin_unlock(&priv->list_lock); + mutex_unlock(&priv->list_lock); return obj;