Merge tag 'drm-misc-fixes-2017-01-31' of git://anongit.freedesktop.org/git/drm-misc into drm-fixes

2 patches to fix the oops Dave Hanse reported, plus a double kfree fix
Maarten discovered while backporting the fix for Linus.

For Linus' vma tracking oops the plan is to send you a dedicated pull with
the 2 patches we need, but since it's tricky we're letting CI beat on it a
bit more.

* tag 'drm-misc-fixes-2017-01-31' of git://anongit.freedesktop.org/git/drm-misc:
  drm/atomic: Fix double free in drm_atomic_state_default_clear
  drm: Don't race connector registration
  drm: prevent double-(un)registration for connectors

5 files changed, 46 insertions, 11 deletions

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index 50f5cf7b69d1..fdfb1ec17e66 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -2032,13 +2032,16 @@ static void complete_crtc_signaling(struct drm_device *dev,
 	}
 
 	for_each_crtc_in_state(state, crtc, crtc_state, i) {
+		struct drm_pending_vblank_event *event = crtc_state->event;
 		/*
-		 * TEST_ONLY and PAGE_FLIP_EVENT are mutually
-		 * exclusive, if they weren't, this code should be
-		 * called on success for TEST_ONLY too.
+		 * Free the allocated event. drm_atomic_helper_setup_commit
+		 * can allocate an event too, so only free it if it's ours
+		 * to prevent a double free in drm_atomic_state_clear.
 		 */
-		if (crtc_state->event)
-			drm_event_cancel_free(dev, &crtc_state->event->base);
+		if (event && (event->base.fence || event->base.file_priv)) {
+			drm_event_cancel_free(dev, &event->base);
+			crtc_state->event = NULL;
+		}
 	}
 
 	if (!fence_state)
diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index 5a4526289392..7a7019ac9388 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -225,6 +225,7 @@ int drm_connector_init(struct drm_device *dev,
 
 	INIT_LIST_HEAD(&connector->probed_modes);
 	INIT_LIST_HEAD(&connector->modes);
+	mutex_init(&connector->mutex);
 	connector->edid_blob_ptr = NULL;
 	connector->status = connector_status_unknown;
 
@@ -359,6 +360,8 @@ void drm_connector_cleanup(struct drm_connector *connector)
 		connector->funcs->atomic_destroy_state(connector,
 						       connector->state);
 
+	mutex_destroy(&connector->mutex);
+
 	memset(connector, 0, sizeof(*connector));
 }
 EXPORT_SYMBOL(drm_connector_cleanup);
@@ -374,14 +377,18 @@ EXPORT_SYMBOL(drm_connector_cleanup);
  */
 int drm_connector_register(struct drm_connector *connector)
 {
-	int ret;
+	int ret = 0;
 
-	if (connector->registered)
+	if (!connector->dev->registered)
 		return 0;
 
+	mutex_lock(&connector->mutex);
+	if (connector->registered)
+		goto unlock;
+
 	ret = drm_sysfs_connector_add(connector);
 	if (ret)
-		return ret;
+		goto unlock;
 
 	ret = drm_debugfs_connector_add(connector);
 	if (ret) {
@@ -397,12 +404,14 @@ int drm_connector_register(struct drm_connector *connector)
 	drm_mode_object_register(connector->dev, &connector->base);
 
 	connector->registered = true;
-	return 0;
+	goto unlock;
 
 err_debugfs:
 	drm_debugfs_connector_remove(connector);
 err_sysfs:
 	drm_sysfs_connector_remove(connector);
+unlock:
+	mutex_unlock(&connector->mutex);
 	return ret;
 }
 EXPORT_SYMBOL(drm_connector_register);
@@ -415,8 +424,11 @@ EXPORT_SYMBOL(drm_connector_register);
  */
 void drm_connector_unregister(struct drm_connector *connector)
 {
-	if (!connector->registered)
+	mutex_lock(&connector->mutex);
+	if (!connector->registered) {
+		mutex_unlock(&connector->mutex);
 		return;
+	}
 
 	if (connector->funcs->early_unregister)
 		connector->funcs->early_unregister(connector);
@@ -425,6 +437,7 @@ void drm_connector_unregister(struct drm_connector *connector)
 	drm_debugfs_connector_remove(connector);
 
 	connector->registered = false;
+	mutex_unlock(&connector->mutex);
 }
 EXPORT_SYMBOL(drm_connector_unregister);
 
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index a525751b4559..6594b4088f11 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -745,6 +745,8 @@ int drm_dev_register(struct drm_device *dev, unsigned long flags)
 	if (ret)
 		goto err_minors;
 
+	dev->registered = true;
+
 	if (dev->driver->load) {
 		ret = dev->driver->load(dev, flags);
 		if (ret)
@@ -785,6 +787,8 @@ void drm_dev_unregister(struct drm_device *dev)
 
 	drm_lastclose(dev);
 
+	dev->registered = false;
+
 	if (drm_core_check_feature(dev, DRIVER_MODESET))
 		drm_modeset_unregister_all(dev);
 
diff --git a/include/drm/drmP.h b/include/drm/drmP.h
index 192016e2b518..9c4ee144b5f6 100644
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -517,6 +517,7 @@ struct drm_device {
 	struct drm_minor *control;		/**< Control node */
 	struct drm_minor *primary;		/**< Primary node */
 	struct drm_minor *render;		/**< Render node */
+	bool registered;
 
 	/* currently active master for this device. Protected by master_mutex */
 	struct drm_master *master;
diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
index a9b95246e26e..045a97cbeba2 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -381,6 +381,8 @@ struct drm_connector_funcs {
 	 * core drm connector interfaces. Everything added from this callback
 	 * should be unregistered in the early_unregister callback.
 	 *
+	 * This is called while holding drm_connector->mutex.
+	 *
 	 * Returns:
 	 *
 	 * 0 on success, or a negative error code on failure.
@@ -395,6 +397,8 @@ struct drm_connector_funcs {
 	 * late_register(). It is called from drm_connector_unregister(),
 	 * early in the driver unload sequence to disable userspace access
 	 * before data structures are torndown.
+	 *
+	 * This is called while holding drm_connector->mutex.
 	 */
 	void (*early_unregister)(struct drm_connector *connector);
 
@@ -559,7 +563,6 @@ struct drm_cmdline_mode {
  * @interlace_allowed: can this connector handle interlaced modes?
  * @doublescan_allowed: can this connector handle doublescan?
  * @stereo_allowed: can this connector handle stereo modes?
- * @registered: is this connector exposed (registered) with userspace?
  * @modes: modes available on this connector (from fill_modes() + user)
  * @status: one of the drm_connector_status enums (connected, not, or unknown)
  * @probed_modes: list of modes derived directly from the display
@@ -608,6 +611,13 @@ struct drm_connector {
 	char *name;
 
 	/**
+	 * @mutex: Lock for general connector state, but currently only protects
+	 * @registered. Most of the connector state is still protected by the
+	 * mutex in &drm_mode_config.
+	 */
+	struct mutex mutex;
+
+	/**
 	 * @index: Compacted connector index, which matches the position inside
 	 * the mode_config.list for drivers not supporting hot-add/removing. Can
 	 * be used as an array index. It is invariant over the lifetime of the
@@ -620,6 +630,10 @@ struct drm_connector {
 	bool interlace_allowed;
 	bool doublescan_allowed;
 	bool stereo_allowed;
+	/**
+	 * @registered: Is this connector exposed (registered) with userspace?
+	 * Protected by @mutex.
+	 */
 	bool registered;
 	struct list_head modes; /* list of modes on this connector */