drm/nouveau: Use drm_connector_list_iter_* for iterating connectors

BugLink: http://bugs.launchpad.net/bugs/1812229
commit 22b76bbe089cd901f5260ecb9a3dc41f9edb97a0 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.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 6ed9cb053dfa5fd3bff312b155541ef17a4aadad..4d3e49afb2843f31c4452aaa5e5845055f5d2734 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 2e7785f49e6d54c1c0941c69de2ff0a869cfd3f0..3ab765b83be7bec1e4bcf6c0c173d0229d6fdc54 100644 (file)
--- a/drivers/gpu/drm/nouveau/nouveau_display.c
+++ b/drivers/gpu/drm/nouveau/nouveau_display.c
@@ -405,6 +405,7 @@ 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);
@@ -412,10 +413,12 @@ 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);
@@ -428,6 +431,7 @@ 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))
@@ -440,10 +444,12 @@ 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);