From: Daniel Stone Date: Fri, 22 May 2015 12:34:51 +0000 (+0100) Subject: drm/mode: Add user blob-creation ioctl X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=e2f5d2ea479b9b2619965d43db70939589afe43a;p=linux-beck.git drm/mode: Add user blob-creation ioctl Add an ioctl which allows users to create blob properties from supplied data. Currently this only supports modes, creating a drm_display_mode from the userspace drm_mode_modeinfo. v2: Removed size/type checks. Rebased on new patches to allow error propagation from create_blob, as well as avoiding double-allocation. Signed-off-by: Daniel Stone Reviewed-by: Maarten Lankhorst Tested-by: Sean Paul Signed-off-by: Daniel Vetter --- diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c index f661589b1dea..e548c50edc94 100644 --- a/drivers/gpu/drm/drm_crtc.c +++ b/drivers/gpu/drm/drm_crtc.c @@ -4173,6 +4173,9 @@ drm_property_create_blob(struct drm_device *dev, size_t length, if (!blob) return ERR_PTR(-ENOMEM); + /* This must be explicitly initialised, so we can safely call list_del + * on it in the removal handler, even if it isn't in a file list. */ + INIT_LIST_HEAD(&blob->head_file); blob->length = length; blob->dev = dev; @@ -4190,7 +4193,8 @@ drm_property_create_blob(struct drm_device *dev, size_t length, kref_init(&blob->refcount); - list_add_tail(&blob->head, &dev->mode_config.property_blob_list); + list_add_tail(&blob->head_global, + &dev->mode_config.property_blob_list); mutex_unlock(&dev->mode_config.blob_lock); @@ -4212,7 +4216,8 @@ static void drm_property_free_blob(struct kref *kref) WARN_ON(!mutex_is_locked(&blob->dev->mode_config.blob_lock)); - list_del(&blob->head); + list_del(&blob->head_global); + list_del(&blob->head_file); drm_mode_object_put(blob->dev, &blob->base); kfree(blob); @@ -4263,6 +4268,26 @@ static void drm_property_unreference_blob_locked(struct drm_property_blob *blob) kref_put(&blob->refcount, drm_property_free_blob); } +/** + * drm_property_destroy_user_blobs - destroy all blobs created by this client + * @dev: DRM device + * @file_priv: destroy all blobs owned by this file handle + */ +void drm_property_destroy_user_blobs(struct drm_device *dev, + struct drm_file *file_priv) +{ + struct drm_property_blob *blob, *bt; + + mutex_lock(&dev->mode_config.blob_lock); + + list_for_each_entry_safe(blob, bt, &file_priv->blobs, head_file) { + list_del_init(&blob->head_file); + drm_property_unreference_blob_locked(blob); + } + + mutex_unlock(&dev->mode_config.blob_lock); +} + /** * drm_property_reference_blob - Take a reference on an existing property * @@ -4452,6 +4477,114 @@ done: return ret; } +/** + * 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; + struct drm_property_blob *blob; + void __user *blob_ptr; + int ret = 0; + + if (!drm_core_check_feature(dev, DRIVER_MODESET)) + return -EINVAL; + + blob = drm_property_create_blob(dev, out_resp->length, NULL); + if (IS_ERR(blob)) + return PTR_ERR(blob); + + blob_ptr = (void __user *)(unsigned long)out_resp->data; + if (copy_from_user(blob->data, blob_ptr, out_resp->length)) { + ret = -EFAULT; + goto out_blob; + } + + /* Dropping the lock between create_blob and our access here is safe + * as only the same file_priv can remove the blob; at this point, it is + * not associated with any file_priv. */ + mutex_lock(&dev->mode_config.blob_lock); + out_resp->blob_id = blob->base.id; + list_add_tail(&file_priv->blobs, &blob->head_file); + mutex_unlock(&dev->mode_config.blob_lock); + + return 0; + +out_blob: + drm_property_unreference_blob(blob); + 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; + bool found = false; + int ret = 0; + + if (!drm_core_check_feature(dev, DRIVER_MODESET)) + return -EINVAL; + + mutex_lock(&dev->mode_config.blob_lock); + blob = __drm_property_lookup_blob(dev, out_resp->blob_id); + if (!blob) { + ret = -ENOENT; + goto err; + } + + /* Ensure the property was actually created by this user. */ + list_for_each_entry(bt, &file_priv->blobs, head_file) { + if (bt == blob) { + found = true; + break; + } + } + + if (!found) { + ret = -EPERM; + goto err; + } + + /* We must drop head_file here, because we may not be the last + * reference on the blob. */ + list_del_init(&blob->head_file); + drm_property_unreference_blob_locked(blob); + mutex_unlock(&dev->mode_config.blob_lock); + + return 0; + +err: + mutex_unlock(&dev->mode_config.blob_lock); + return ret; +} + /** * drm_mode_connector_set_path_property - set tile property on connector * @connector: connector to set property on. @@ -5655,7 +5788,7 @@ void drm_mode_config_cleanup(struct drm_device *dev) } list_for_each_entry_safe(blob, bt, &dev->mode_config.property_blob_list, - head) { + head_global) { drm_property_unreference_blob(blob); } diff --git a/drivers/gpu/drm/drm_fops.c b/drivers/gpu/drm/drm_fops.c index 0f6a5c8801e3..c59ce4d0ef75 100644 --- a/drivers/gpu/drm/drm_fops.c +++ b/drivers/gpu/drm/drm_fops.c @@ -167,6 +167,7 @@ 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->blobs); INIT_LIST_HEAD(&priv->event_list); init_waitqueue_head(&priv->event_wait); priv->event_space = 4096; /* set aside 4k for event buffer */ @@ -405,8 +406,10 @@ 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); diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c index 266dcd6cdf3b..9bac1b7479af 100644 --- a/drivers/gpu/drm/drm_ioctl.c +++ b/drivers/gpu/drm/drm_ioctl.c @@ -641,6 +641,8 @@ 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 df6d9970d9a4..9fa6366f47c2 100644 --- a/include/drm/drmP.h +++ b/include/drm/drmP.h @@ -326,6 +326,10 @@ 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 blobs; + 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 dace1b635685..72b60dbe0891 100644 --- a/include/drm/drm_crtc.h +++ b/include/drm/drm_crtc.h @@ -218,7 +218,8 @@ struct drm_property_blob { struct drm_mode_object base; struct drm_device *dev; struct kref refcount; - struct list_head head; + struct list_head head_global; + struct list_head head_file; size_t length; unsigned char data[]; }; @@ -1315,6 +1316,8 @@ 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); @@ -1460,6 +1463,10 @@ 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 ff6ef62d084b..3801584a0c53 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 dbeba949462a..359107ab629e 100644 --- a/include/uapi/drm/drm_mode.h +++ b/include/uapi/drm/drm_mode.h @@ -558,4 +558,24 @@ struct drm_mode_atomic { __u64 user_data; }; +/** + * Create a new 'blob' data property, copying length bytes from data pointer, + * and returning new blob ID. + */ +struct drm_mode_create_blob { + /** Pointer to data to copy. */ + __u64 data; + /** Length of data to copy. */ + __u32 length; + /** Return: new property ID. */ + __u32 blob_id; +}; + +/** + * Destroy a user-created blob property. + */ +struct drm_mode_destroy_blob { + __u32 blob_id; +}; + #endif