Add an ioctl which allows users to create objects from arbitrary data.
Currently this only supports modes, creating a drm_display_mode from the
userspace drm_mode_modeinfo.

Signed-off-by: Daniel Stone <daniels at collabora.com>
---
 drivers/gpu/drm/drm_crtc.c  | 166 ++++++++++++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/drm_fops.c  |   7 +-
 drivers/gpu/drm/drm_ioctl.c |   2 +
 include/drm/drmP.h          |   6 ++
 include/drm/drm_crtc.h      |   6 ++
 include/uapi/drm/drm.h      |   2 +
 include/uapi/drm/drm_mode.h |  22 ++++++
 7 files changed, 209 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index 21e2052..e258e7c 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -4155,6 +4155,19 @@ static void drm_property_destroy_blob(struct drm_device 
*dev,
        kfree(blob);
 }

+void drm_property_destroy_user_blobs(struct drm_device *dev,
+                                    struct drm_file *file_priv)
+{
+       struct drm_property_blob *blob, *bt;
+
+       mutex_lock(&file_priv->properties_lock);
+       list_for_each_entry_safe(blob, bt, &file_priv->properties, head) {
+               drm_property_destroy_blob(dev, blob);
+       }
+       mutex_unlock(&file_priv->properties_lock);
+       mutex_destroy(&file_priv->properties_lock);
+}
+
 /**
  * drm_mode_getblob_ioctl - get the contents of a blob property value
  * @dev: DRM device
@@ -4216,6 +4229,159 @@ done:
 }

 /**
+ * drm_mode_createblob_ioctl - create a new blob property
+ * @dev: DRM device
+ * @data: ioctl data
+ * @file_priv: DRM file info
+ *
+ * This function creates a new blob property with user-defined values. In order
+ * to give us sensible validation and checking when creating, rather than at
+ * every potential use, we also require a type to be provided upfront.
+ *
+ * Called by the user via ioctl.
+ *
+ * Returns:
+ * Zero on success, negative errno on failure.
+ */
+int drm_mode_createblob_ioctl(struct drm_device *dev,
+                             void *data, struct drm_file *file_priv)
+{
+       struct drm_mode_create_blob *out_resp = data;
+       uint32_t length = 0;
+       void *blob_data;
+       int ret = 0;
+       void __user *blob_ptr;
+
+       if (!drm_core_check_feature(dev, DRIVER_MODESET))
+               return -EINVAL;
+
+       switch (out_resp->type) {
+       case DRM_MODE_BLOB_TYPE_MODE: {
+               length = sizeof(struct drm_mode_modeinfo);
+               if (out_resp->length != length) {
+                       ret = -E2BIG;
+                       goto out_unlocked;
+               }
+               break;
+       }
+       default:
+               ret = -EINVAL;
+               goto out_unlocked;
+       }
+
+       blob_data = kzalloc(length, GFP_USER);
+       if (!blob_data) {
+               ret = -ENOMEM;
+               goto out_unlocked;
+       }
+
+       blob_ptr = (void __user *)(unsigned long)out_resp->data;
+       if (copy_from_user(blob_data, blob_ptr, out_resp->length)) {
+               ret = -EFAULT;
+               goto out_data;
+       }
+
+       drm_modeset_lock_all(dev);
+
+       switch (out_resp->type) {
+       case DRM_MODE_BLOB_TYPE_MODE: {
+               struct drm_display_mode *mode;
+
+               mode = drm_mode_new_from_umode(dev, blob_data);
+               if (!mode) {
+                       ret = -EINVAL;
+                       goto out_locked;
+               }
+
+               out_resp->blob_id = mode->base.id;
+
+               /* XXX: When we were using a property as the base here, we
+                *      added the mode to the properties list to ensure it
+                *      got cleaned up when the drm_file disappeared. But
+                *      by using drm_display_mode as the base object, we
+                *      can't add it to the list anymore. Adding a specific
+                *      mode list feels pretty unclean though ...
+               mutex_lock(&file_priv->properties_lock);
+               list_add_tail(&blob->head, &file_priv->properties);
+               mutex_unlock(&file_priv->properties_lock); */
+
+               break;
+       }
+       }
+
+out_locked:
+       drm_modeset_unlock_all(dev);
+out_data:
+       kfree(blob_data);
+out_unlocked:
+       return ret;
+}
+
+/**
+ * drm_mode_destroyblob_ioctl - destroy a user blob property
+ * @dev: DRM device
+ * @data: ioctl data
+ * @file_priv: DRM file info
+ *
+ * Destroy an existing user-defined blob property.
+ *
+ * Called by the user via ioctl.
+ *
+ * Returns:
+ * Zero on success, negative errno on failure.
+ */
+int drm_mode_destroyblob_ioctl(struct drm_device *dev,
+                              void *data, struct drm_file *file_priv)
+{
+       struct drm_mode_destroy_blob *out_resp = data;
+       struct drm_property_blob *blob = NULL, *bt;
+       struct drm_display_mode *mode = NULL;
+       bool found = false;
+       int ret = 0;
+
+       if (!drm_core_check_feature(dev, DRIVER_MODESET))
+               return -EINVAL;
+
+       drm_modeset_lock_all(dev);
+       blob = drm_property_blob_find(dev, out_resp->blob_id);
+       if (!blob)
+               mode = drm_mode_find(dev, out_resp->blob_id);
+
+       if (!blob && !mode) {
+               ret = -ENOENT;
+               goto out_locked;
+       }
+
+       /* Ensure the property was actually created by this user. */
+       if (blob) {
+               mutex_lock(&file_priv->properties_lock);
+
+               list_for_each_entry(bt, &file_priv->properties, head) {
+                       if (bt == blob) {
+                               found = true;
+                               break;
+                       }
+               }
+
+               if (found) {
+                       drm_property_destroy_blob(dev, blob);
+                       ret = 0;
+               } else {
+                       ret = -EPERM;
+               }
+
+               mutex_unlock(&file_priv->properties_lock);
+       } else if (mode) {
+               /* XXX: This is missing all the nice checking from above ... */
+               drm_mode_destroy(dev, mode);
+       }
+
+out_locked:
+       drm_modeset_unlock_all(dev);
+       return ret;
+}
+
+/**
  * drm_mode_connector_set_path_property - set tile property on connector
  * @connector: connector to set property on.
  * @path: path to use for property.
diff --git a/drivers/gpu/drm/drm_fops.c b/drivers/gpu/drm/drm_fops.c
index 076dd60..6e389ea 100644
--- a/drivers/gpu/drm/drm_fops.c
+++ b/drivers/gpu/drm/drm_fops.c
@@ -167,6 +167,8 @@ static int drm_open_helper(struct file *filp, struct 
drm_minor *minor)
        INIT_LIST_HEAD(&priv->lhead);
        INIT_LIST_HEAD(&priv->fbs);
        mutex_init(&priv->fbs_lock);
+       INIT_LIST_HEAD(&priv->properties);
+       mutex_init(&priv->properties_lock);
        INIT_LIST_HEAD(&priv->event_list);
        init_waitqueue_head(&priv->event_wait);
        priv->event_space = 4096; /* set aside 4k for event buffer */
@@ -408,8 +410,10 @@ int drm_release(struct inode *inode, struct file *filp)

        drm_events_release(file_priv);

-       if (drm_core_check_feature(dev, DRIVER_MODESET))
+       if (drm_core_check_feature(dev, DRIVER_MODESET)) {
                drm_fb_release(file_priv);
+               drm_property_destroy_user_blobs(dev, file_priv);
+       }

        if (drm_core_check_feature(dev, DRIVER_GEM))
                drm_gem_release(dev, file_priv);
@@ -452,7 +456,6 @@ int drm_release(struct inode *inode, struct file *filp)
        if (dev->driver->postclose)
                dev->driver->postclose(dev, file_priv);

-
        if (drm_core_check_feature(dev, DRIVER_PRIME))
                drm_prime_destroy_file_private(&file_priv->prime);

diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c
index a6d773a..d180377 100644
--- a/drivers/gpu/drm/drm_ioctl.c
+++ b/drivers/gpu/drm/drm_ioctl.c
@@ -636,6 +636,8 @@ static const struct drm_ioctl_desc drm_ioctls[] = {
        DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_SETPROPERTY, 
drm_mode_obj_set_property_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
        DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR2, drm_mode_cursor2_ioctl, 
DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
        DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATOMIC, drm_mode_atomic_ioctl, 
DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
+       DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATEPROPBLOB, drm_mode_createblob_ioctl, 
DRM_CONTROL_ALLOW|DRM_UNLOCKED),
+       DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROYPROPBLOB, 
drm_mode_destroyblob_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 };

 #define DRM_CORE_IOCTL_COUNT   ARRAY_SIZE( drm_ioctls )
diff --git a/include/drm/drmP.h b/include/drm/drmP.h
index 63c0b01..62b4d8d 100644
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -322,6 +322,12 @@ struct drm_file {
        struct list_head fbs;
        struct mutex fbs_lock;

+       /** User-created blob properties; this retains a reference on the
+        *  property. */
+       struct list_head properties;
+       /** Lock for synchronisation of access to properties. */
+       struct mutex properties_lock;
+
        wait_queue_head_t event_wait;
        struct list_head event_list;
        int event_space;
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index 5c8cb25..d4d914c 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -1284,6 +1284,8 @@ extern const char *drm_get_dvi_i_select_name(int val);
 extern const char *drm_get_tv_subconnector_name(int val);
 extern const char *drm_get_tv_select_name(int val);
 extern void drm_fb_release(struct drm_file *file_priv);
+extern void drm_property_destroy_user_blobs(struct drm_device *dev,
+                                            struct drm_file *file_priv);
 extern int drm_mode_group_init_legacy_group(struct drm_device *dev, struct 
drm_mode_group *group);
 extern void drm_mode_group_destroy(struct drm_mode_group *group);
 extern void drm_reinit_primary_mode_group(struct drm_device *dev);
@@ -1422,6 +1424,10 @@ extern int drm_mode_getproperty_ioctl(struct drm_device 
*dev,
                                      void *data, struct drm_file *file_priv);
 extern int drm_mode_getblob_ioctl(struct drm_device *dev,
                                  void *data, struct drm_file *file_priv);
+extern int drm_mode_createblob_ioctl(struct drm_device *dev,
+                                    void *data, struct drm_file *file_priv);
+extern int drm_mode_destroyblob_ioctl(struct drm_device *dev,
+                                     void *data, struct drm_file *file_priv);
 extern int drm_mode_connector_property_set_ioctl(struct drm_device *dev,
                                              void *data, struct drm_file 
*file_priv);
 extern int drm_mode_getencoder(struct drm_device *dev,
diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h
index ff6ef62..3801584 100644
--- a/include/uapi/drm/drm.h
+++ b/include/uapi/drm/drm.h
@@ -786,6 +786,8 @@ struct drm_prime_handle {
 #define DRM_IOCTL_MODE_OBJ_SETPROPERTY DRM_IOWR(0xBA, struct 
drm_mode_obj_set_property)
 #define DRM_IOCTL_MODE_CURSOR2         DRM_IOWR(0xBB, struct drm_mode_cursor2)
 #define DRM_IOCTL_MODE_ATOMIC          DRM_IOWR(0xBC, struct drm_mode_atomic)
+#define DRM_IOCTL_MODE_CREATEPROPBLOB  DRM_IOWR(0xBD, struct 
drm_mode_create_blob)
+#define DRM_IOCTL_MODE_DESTROYPROPBLOB DRM_IOWR(0xBE, struct 
drm_mode_destroy_blob)

 /**
  * Device specific ioctls should only be in their respective headers
diff --git a/include/uapi/drm/drm_mode.h b/include/uapi/drm/drm_mode.h
index dbeba94..73ac925 100644
--- a/include/uapi/drm/drm_mode.h
+++ b/include/uapi/drm/drm_mode.h
@@ -558,4 +558,26 @@ struct drm_mode_atomic {
        __u64 user_data;
 };

+#define DRM_MODE_BLOB_TYPE_MODE                1 /**< drm_mode_modeinfo */
+
+/**
+ * Create a new 'blob' data property, copying length bytes from data pointer,
+ * and returning new blob ID.
+ */
+struct drm_mode_create_blob {
+       __u32 type;
+       __u32 length;
+       /** Pointer to data to create blob. */
+       __u64 data;
+       /** Return: new property ID. */
+       __u32 blob_id;
+};
+
+/**
+ * Destroy a user-created blob property.
+ */
+struct drm_mode_destroy_blob {
+       __u32 blob_id;
+};
+
 #endif
-- 
2.3.2

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