From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934084AbbIVSQM (ORCPT ); Tue, 22 Sep 2015 14:16:12 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:42828 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759361AbbIVRxv (ORCPT ); Tue, 22 Sep 2015 13:53:51 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Dave Airlie , Maarten Lankhorst , Jani Nikula , Kamal Mostafa Subject: [PATCH 3.19.y-ckt 053/102] drm/dp/mst: Remove port after removing connector. Date: Tue, 22 Sep 2015 10:51:49 -0700 Message-Id: <1442944358-1248-54-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1442944358-1248-1-git-send-email-kamal@canonical.com> References: <1442944358-1248-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.19 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.19.8-ckt7 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Maarten Lankhorst commit 4772ff03df8094fd99d28de5fcf5df3a3e9c68bb upstream. The port is removed synchronously, but the connector delayed. This causes a use after free which can cause a kernel BUG with slug_debug=FPZU. This is fixed by freeing the port after the connector. This fixes a regression introduced with 6b8eeca65b18ae77e175cc2b6571731f0ee413bf "drm/dp/mst: close deadlock in connector destruction." Cc: Dave Airlie Signed-off-by: Maarten Lankhorst Reviewed-by: Daniel Vetter Signed-off-by: Jani Nikula Signed-off-by: Kamal Mostafa --- drivers/gpu/drm/drm_dp_mst_topology.c | 19 +++++++++++++------ include/drm/drm_crtc.h | 2 -- 2 files changed, 13 insertions(+), 8 deletions(-) diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index 8239563..6c0a1b0 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -869,9 +869,10 @@ static void drm_dp_destroy_port(struct kref *kref) from an EDID retrieval */ if (port->connector) { mutex_lock(&mgr->destroy_connector_lock); - list_add(&port->connector->destroy_list, &mgr->destroy_connector_list); + list_add(&port->next, &mgr->destroy_connector_list); mutex_unlock(&mgr->destroy_connector_lock); schedule_work(&mgr->destroy_connector_work); + return; } drm_dp_port_teardown_pdt(port, port->pdt); @@ -2641,7 +2642,7 @@ static void drm_dp_tx_work(struct work_struct *work) static void drm_dp_destroy_connector_work(struct work_struct *work) { struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, destroy_connector_work); - struct drm_connector *connector; + struct drm_dp_mst_port *port; /* * Not a regular list traverse as we have to drop the destroy @@ -2650,15 +2651,21 @@ static void drm_dp_destroy_connector_work(struct work_struct *work) */ for (;;) { mutex_lock(&mgr->destroy_connector_lock); - connector = list_first_entry_or_null(&mgr->destroy_connector_list, struct drm_connector, destroy_list); - if (!connector) { + port = list_first_entry_or_null(&mgr->destroy_connector_list, struct drm_dp_mst_port, next); + if (!port) { mutex_unlock(&mgr->destroy_connector_lock); break; } - list_del(&connector->destroy_list); + list_del(&port->next); mutex_unlock(&mgr->destroy_connector_lock); - mgr->cbs->destroy_connector(mgr, connector); + mgr->cbs->destroy_connector(mgr, port->connector); + + drm_dp_port_teardown_pdt(port, port->pdt); + + if (!port->input && port->vcpi.vcpi > 0) + drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi); + kfree(port); } } diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h index 3dab77c..b863298 100644 --- a/include/drm/drm_crtc.h +++ b/include/drm/drm_crtc.h @@ -689,8 +689,6 @@ struct drm_connector { uint8_t num_h_tile, num_v_tile; uint8_t tile_h_loc, tile_v_loc; uint16_t tile_h_size, tile_v_size; - - struct list_head destroy_list; }; /** -- 1.9.1