drm: Move property validation to a helper, v2.

Property lifetimes are equal to the device lifetime, so the separate
drm_property_find is not needed. The pointer can be retrieved from
the properties member, which saves us some locking and a extra lookup.
The lifetime for properties is until the device is destroyed, which
happens late in the device unload path.

kms_atomic is also testing for invalid properties which returns -ENOENT,
to be consistent return -ENOENT for valid properties that don't appear
on the object property list.

Changes since v1:
- Return -ENOENT for invalid properties to make kms_atomic pass.
- Change commit message slightly to take this into account.

Testcase: kms_atomic
Testcase: kms_properties
Fixes: 4e9951d96093 ("drm/atomic: Reject properties not part of the object.")
Suggested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/599c7fa8-b6fd-a42b-c619-a9e4a9c5c244@linux.intel.com

3 files changed, 20 insertions, 26 deletions

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index a5126e5c05ee..904d29c012ad 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -1609,7 +1609,7 @@ int drm_mode_atomic_ioctl(struct drm_device *dev,
         struct drm_crtc_state *crtc_state;
         unsigned plane_mask;
         int ret = 0;
-        unsigned int i, j, k;
+        unsigned int i, j;
 
         /* disallow for drivers not supporting atomic: */
         if (!drm_core_check_feature(dev, DRIVER_ATOMIC))
@@ -1691,16 +1691,7 @@ retry:
                                 goto out;
                         }
 
-                        for (k = 0; k < obj->properties->count; k++)
-                                if (obj->properties->properties[k]->base.id == prop_id)
-                                        break;
-
-                        if (k == obj->properties->count) {
-                                ret = -EINVAL;
-                                goto out;
-                        }
-
-                        prop = drm_property_find(dev, prop_id);
+                        prop = drm_mode_obj_find_prop_id(obj, prop_id);
                         if (!prop) {
                                 drm_mode_object_unreference(obj);
                                 ret = -ENOENT;
diff --git a/drivers/gpu/drm/drm_crtc_internal.h b/drivers/gpu/drm/drm_crtc_internal.h
index a3622644bccf..444e609078cc 100644
--- a/drivers/gpu/drm/drm_crtc_internal.h
+++ b/drivers/gpu/drm/drm_crtc_internal.h
@@ -115,6 +115,8 @@ int drm_mode_object_get_properties(struct drm_mode_object *obj, bool atomic,
                                    uint32_t __user *prop_ptr,
                                    uint64_t __user *prop_values,
                                    uint32_t *arg_count_props);
+struct drm_property *drm_mode_obj_find_prop_id(struct drm_mode_object *obj,
+                                               uint32_t prop_id);
 
 /* IOCTL */
 
diff --git a/drivers/gpu/drm/drm_mode_object.c b/drivers/gpu/drm/drm_mode_object.c
index 6edda8382a4c..9f17085b1fdd 100644
--- a/drivers/gpu/drm/drm_mode_object.c
+++ b/drivers/gpu/drm/drm_mode_object.c
@@ -372,14 +372,25 @@ out:
         return ret;
 }
 
+struct drm_property *drm_mode_obj_find_prop_id(struct drm_mode_object *obj,
+                                               uint32_t prop_id)
+{
+        int i;
+
+        for (i = 0; i < obj->properties->count; i++)
+                if (obj->properties->properties[i]->base.id == prop_id)
+                        return obj->properties->properties[i];
+
+        return NULL;
+}
+
 int drm_mode_obj_set_property_ioctl(struct drm_device *dev, void *data,
                                     struct drm_file *file_priv)
 {
         struct drm_mode_obj_set_property *arg = data;
         struct drm_mode_object *arg_obj;
-        struct drm_mode_object *prop_obj;
         struct drm_property *property;
-        int i, ret = -EINVAL;
+        int ret = -EINVAL;
         struct drm_mode_object *ref;
 
         if (!drm_core_check_feature(dev, DRIVER_MODESET))
@@ -392,23 +403,13 @@ int drm_mode_obj_set_property_ioctl(struct drm_device *dev, void *data,
                 ret = -ENOENT;
                 goto out;
         }
-        if (!arg_obj->properties)
-                goto out_unref;
-
-        for (i = 0; i < arg_obj->properties->count; i++)
-                if (arg_obj->properties->properties[i]->base.id == arg->prop_id)
-                        break;
 
-        if (i == arg_obj->properties->count)
+        if (!arg_obj->properties)
                 goto out_unref;
 
-        prop_obj = drm_mode_object_find(dev, arg->prop_id,
-                                        DRM_MODE_OBJECT_PROPERTY);
-        if (!prop_obj) {
-                ret = -ENOENT;
+        property = drm_mode_obj_find_prop_id(arg_obj, arg->prop_id);
+        if (!property)
                 goto out_unref;
-        }
-        property = obj_to_property(prop_obj);
 
         if (!drm_property_change_valid_get(property, arg->value, &ref))
                 goto out_unref;