drm/nouveau: Use drm_connector_list_iter_* for iterating connectors

Every codepath in nouveau that loops through the connector list
currently does so using the old method, which is prone to race
conditions from MST connectors being created and destroyed. This has
been causing a multitude of problems, including memory corruption from
trying to access connectors that have already been freed!

Signed-off-by: Lyude Paul <lyude@redhat.com>
Cc: stable@vger.kernel.org
Cc: Karol Herbst <karolherbst@gmail.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

diff --git a/drivers/gpu/drm/nouveau/nouveau_backlight.c b/drivers/gpu/drm/nouveau/nouveau_backlight.c
index debbbf0fd4bdda619732c67952c772f9957c4166..408b955e5c39a6b41043c18fb37ae8dc9de42c04 100644 (file)
--- a/drivers/gpu/drm/nouveau/nouveau_backlight.c
+++ b/drivers/gpu/drm/nouveau/nouveau_backlight.c
@@ -267,6 +267,7 @@ nouveau_backlight_init(struct drm_device *dev)
        struct nouveau_drm *drm = nouveau_drm(dev);
        struct nvif_device *device = &drm->client.device;
        struct drm_connector *connector;
+       struct drm_connector_list_iter conn_iter;
 
        INIT_LIST_HEAD(&drm->bl_connectors);
 
@@ -275,7 +276,8 @@ nouveau_backlight_init(struct drm_device *dev)
                return 0;
        }
 
-       list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
+       drm_connector_list_iter_begin(dev, &conn_iter);
+       drm_for_each_connector_iter(connector, &conn_iter) {
                if (connector->connector_type != DRM_MODE_CONNECTOR_LVDS &&
                    connector->connector_type != DRM_MODE_CONNECTOR_eDP)
                        continue;
@@ -292,7 +294,7 @@ nouveau_backlight_init(struct drm_device *dev)
                        break;
                }
        }
-
+       drm_connector_list_iter_end(&conn_iter);
 
        return 0;
 }

diff --git a/drivers/gpu/drm/nouveau/nouveau_connector.c b/drivers/gpu/drm/nouveau/nouveau_connector.c
index 7b557c3543079128ff339b79320c62d6bfb36334..7dc3804492321811be579ae31bfa1fef73d11202 100644 (file)
--- a/drivers/gpu/drm/nouveau/nouveau_connector.c
+++ b/drivers/gpu/drm/nouveau/nouveau_connector.c
@@ -1208,14 +1208,19 @@ nouveau_connector_create(struct drm_device *dev, int index)
        struct nouveau_display *disp = nouveau_display(dev);
        struct nouveau_connector *nv_connector = NULL;
        struct drm_connector *connector;
+       struct drm_connector_list_iter conn_iter;
        int type, ret = 0;
        bool dummy;
 
-       list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
+       drm_connector_list_iter_begin(dev, &conn_iter);
+       drm_for_each_connector_iter(connector, &conn_iter) {
                nv_connector = nouveau_connector(connector);
-               if (nv_connector->index == index)
+               if (nv_connector->index == index) {
+                       drm_connector_list_iter_end(&conn_iter);
                        return connector;
+               }
        }
+       drm_connector_list_iter_end(&conn_iter);
 
        nv_connector = kzalloc(sizeof(*nv_connector), GFP_KERNEL);
        if (!nv_connector)

diff --git a/drivers/gpu/drm/nouveau/nouveau_connector.h b/drivers/gpu/drm/nouveau/nouveau_connector.h
index a4d1a059bd3d4f948c36c0a942150c68199ec974..a8cbb4b56fc7d6b5041e97bcf49ce06905aed8dd 100644 (file)
--- a/drivers/gpu/drm/nouveau/nouveau_connector.h
+++ b/drivers/gpu/drm/nouveau/nouveau_connector.h
@@ -65,14 +65,20 @@ nouveau_crtc_connector_get(struct nouveau_crtc *nv_crtc)
 {
        struct drm_device *dev = nv_crtc->base.dev;
        struct drm_connector *connector;
+       struct drm_connector_list_iter conn_iter;
+       struct nouveau_connector *nv_connector = NULL;
        struct drm_crtc *crtc = to_drm_crtc(nv_crtc);
 
-       list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
-               if (connector->encoder && connector->encoder->crtc == crtc)
-                       return nouveau_connector(connector);
+       drm_connector_list_iter_begin(dev, &conn_iter);
+       drm_for_each_connector_iter(connector, &conn_iter) {
+               if (connector->encoder && connector->encoder->crtc == crtc) {
+                       nv_connector = nouveau_connector(connector);
+                       break;
+               }
        }
+       drm_connector_list_iter_end(&conn_iter);
 
-       return NULL;
+       return nv_connector;
 }
 
 struct drm_connector *

diff --git a/drivers/gpu/drm/nouveau/nouveau_display.c b/drivers/gpu/drm/nouveau/nouveau_display.c
index 774b429142bc8e22c79e6b0ed46f97f72e3ffab1..46b8430ef4aa016b7ebcc10014af6006df92c943 100644 (file)
--- a/drivers/gpu/drm/nouveau/nouveau_display.c
+++ b/drivers/gpu/drm/nouveau/nouveau_display.c
@@ -404,6 +404,7 @@ nouveau_display_init(struct drm_device *dev)
        struct nouveau_display *disp = nouveau_display(dev);
        struct nouveau_drm *drm = nouveau_drm(dev);
        struct drm_connector *connector;
+       struct drm_connector_list_iter conn_iter;
        int ret;
 
        ret = disp->init(dev);
@@ -411,10 +412,12 @@ nouveau_display_init(struct drm_device *dev)
                return ret;
 
        /* enable hotplug interrupts */
-       list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
+       drm_connector_list_iter_begin(dev, &conn_iter);
+       drm_for_each_connector_iter(connector, &conn_iter) {
                struct nouveau_connector *conn = nouveau_connector(connector);
                nvif_notify_get(&conn->hpd);
        }
+       drm_connector_list_iter_end(&conn_iter);
 
        /* enable flip completion events */
        nvif_notify_get(&drm->flip);
@@ -427,6 +430,7 @@ nouveau_display_fini(struct drm_device *dev, bool suspend)
        struct nouveau_display *disp = nouveau_display(dev);
        struct nouveau_drm *drm = nouveau_drm(dev);
        struct drm_connector *connector;
+       struct drm_connector_list_iter conn_iter;
 
        if (!suspend) {
                if (drm_drv_uses_atomic_modeset(dev))
@@ -439,10 +443,12 @@ nouveau_display_fini(struct drm_device *dev, bool suspend)
        nvif_notify_put(&drm->flip);
 
        /* disable hotplug interrupts */
-       list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
+       drm_connector_list_iter_begin(dev, &conn_iter);
+       drm_for_each_connector_iter(connector, &conn_iter) {
                struct nouveau_connector *conn = nouveau_connector(connector);
                nvif_notify_put(&conn->hpd);
        }
+       drm_connector_list_iter_end(&conn_iter);
 
        drm_kms_helper_poll_disable(dev);
        disp->fini(dev);