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authorMaarten Lankhorst <maarten.lankhorst@linux.intel.com>2015-08-11 10:54:29 +0300
committerJani Nikula <jani.nikula@intel.com>2015-08-11 12:30:38 +0300
commit4772ff03df8094fd99d28de5fcf5df3a3e9c68bb (patch)
tree2a4d3df228d96c5aac622bdcf1a7289a08bcc5bb /drivers/gpu/drm/drm_dp_mst_topology.c
parent5677d67ae3949f09f57357241b88222d49b8c782 (diff)
downloadlinux-4772ff03df8094fd99d28de5fcf5df3a3e9c68bb.tar.xz
drm/dp/mst: Remove port after removing connector.
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: stable@vger.kernel.org Cc: Dave Airlie <airlied@redhat.com> Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Diffstat (limited to 'drivers/gpu/drm/drm_dp_mst_topology.c')
-rw-r--r--drivers/gpu/drm/drm_dp_mst_topology.c19
1 files changed, 13 insertions, 6 deletions
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index 778bbb6425b8..1325eecb0510 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -873,9 +873,10 @@ 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);
@@ -2660,7 +2661,7 @@ 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
@@ -2669,15 +2670,21 @@ 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);
}
}