DRM_IOCTL_HANDLE_SET_LABEL lets you label buffers associated with a handle, making it easier to debug issues in userspace applications.
DRM_IOCTL_HANDLE_GET_LABEL lets you read the label associated with a buffer.
Changes in v2: - Hoist the IOCTL up into the drm_driver framework
Changes in v3: - Introduce a drm_gem_set_label for drivers to use internally in order to label a GEM object - Hoist string copying up into the IOCTL - Fix documentation - Move actual gem labeling into drm_gem_adopt_label
Changes in v4: - Refactor IOCTL call to only perform string duplication and move all gem lookup logic into GEM specific call
Changes in v5: - Fix issues pointed out by kbuild test robot - Cleanup minor issues around kfree and out/err labels - Fixed API documentation issues - Rename to DRM_IOCTL_HANDLE_SET_LABEL - Introduce a DRM_IOCTL_HANDLE_GET_LABEL to read labels - Added some documentation for consumers of this IOCTL - Ensure that label's cannot be longer than PAGE_SIZE - Set a default label value - Drop useless warning - Properly return length of label to userspace even if userspace did not allocate memory for label.
Changes in v6: - Wrap code to make better use of 80 char limit - Drop redundant copies of the label - Protect concurrent access to labels - Improved documentation - Refactor setter/getter ioctl's to be static - Return EINVAL when label length > PAGE_SIZE - Simplify code by calling the default GEM label'ing function for all drivers using GEM - Do not error out when fetching empty labels - Refactor flags to the u32 type and add documentation - Refactor ioctls to use correct DRM_IOCTL{R,W,WR} macros - Return length of copied label to userspace
Signed-off-by: Rohan Garg rohan.garg@collabora.com --- drivers/gpu/drm/drm_gem.c | 68 +++++++++++++++++++++++++++++++++ drivers/gpu/drm/drm_internal.h | 5 +++ drivers/gpu/drm/drm_ioctl.c | 70 ++++++++++++++++++++++++++++++++++ include/drm/drm_drv.h | 30 +++++++++++++++ include/drm/drm_gem.h | 19 +++++++++ include/uapi/drm/drm.h | 25 +++++++++++- 6 files changed, 216 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c index efc0367841e2..942479dc152f 100644 --- a/drivers/gpu/drm/drm_gem.c +++ b/drivers/gpu/drm/drm_gem.c @@ -154,8 +154,10 @@ void drm_gem_private_object_init(struct drm_device *dev,
obj->dev = dev; obj->filp = NULL; + obj->label = NULL;
kref_init(&obj->refcount); + mutex_init(&obj->bo_lock); obj->handle_count = 0; obj->size = size; dma_resv_init(&obj->_resv); @@ -940,6 +942,69 @@ drm_gem_release(struct drm_device *dev, struct drm_file *file_private) idr_destroy(&file_private->object_idr); }
+int drm_gem_set_label(struct drm_device *dev, struct drm_file *file_priv, + struct drm_handle_label *args) +{ + struct drm_gem_object *gem_obj; + struct pid *_pid = get_task_pid(current, PIDTYPE_PID); + char *label; + + gem_obj = drm_gem_object_lookup(file_priv, args->handle); + if (!gem_obj) { + DRM_DEBUG("Failed to look up GEM BO %d\n", args->handle); + return -ENOENT; + } + + if (args->len && args->label) + label = strndup_user(u64_to_user_ptr(args->label), + args->len + 1); + else + label = NULL; + + drm_gem_adopt_label(gem_obj, label); + drm_gem_object_put(gem_obj); + return args->len; +} +EXPORT_SYMBOL(drm_gem_set_label); + +void drm_gem_adopt_label(struct drm_gem_object *gem_obj, const char *label) +{ + mutex_lock(&gem_obj->bo_lock); + kfree(gem_obj->label); + gem_obj->label = label; + mutex_unlock(&gem_obj->bo_lock); +} +EXPORT_SYMBOL(drm_gem_adopt_label); + +int drm_gem_get_label(struct drm_device *dev, struct drm_file *file_priv, + struct drm_handle_label *args) +{ + struct drm_gem_object *gem_obj; + int len, ret; + + gem_obj = drm_gem_object_lookup(file_priv, args->handle); + if (!gem_obj) { + DRM_DEBUG("Failed to look up GEM BO %d\n", args->handle); + return -ENOENT; + } + + if (!gem_obj->label) { + args->label = NULL; + args->len = 0; + return 0; + } + + mutex_lock(&gem_obj->bo_lock); + len = strlen(gem_obj->label); + ret = copy_to_user(u64_to_user_ptr(args->label), gem_obj->label, + min(args->len, len)); + mutex_unlock(&gem_obj->bo_lock); + args->len = len; + drm_gem_object_put(gem_obj); + return ret; +} +EXPORT_SYMBOL(drm_gem_get_label); + /** * drm_gem_object_release - release GEM buffer object resources * @obj: GEM buffer object @@ -957,6 +1022,9 @@ drm_gem_object_release(struct drm_gem_object *obj)
dma_resv_fini(&obj->_resv); drm_gem_free_mmap_offset(obj); + + kfree(obj->label); + mutex_destroy(&obj->bo_lock); } EXPORT_SYMBOL(drm_gem_object_release);
diff --git a/drivers/gpu/drm/drm_internal.h b/drivers/gpu/drm/drm_internal.h index 2470a352730b..73fd87860100 100644 --- a/drivers/gpu/drm/drm_internal.h +++ b/drivers/gpu/drm/drm_internal.h @@ -161,6 +161,11 @@ int drm_gem_pin(struct drm_gem_object *obj); void drm_gem_unpin(struct drm_gem_object *obj); void *drm_gem_vmap(struct drm_gem_object *obj); void drm_gem_vunmap(struct drm_gem_object *obj, void *vaddr); +int drm_gem_set_label(struct drm_device *dev, struct drm_file *file_priv, + struct drm_handle_label *args); +void drm_gem_adopt_label(struct drm_gem_object *gem_obj, const char *label); +int drm_gem_get_label(struct drm_device *dev, struct drm_file *file_priv, + struct drm_handle_label *args);
/* drm_debugfs.c drm_debugfs_crc.c */ #if defined(CONFIG_DEBUG_FS) diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c index 0fb9da24eaa4..04ff75e53349 100644 --- a/drivers/gpu/drm/drm_ioctl.c +++ b/drivers/gpu/drm/drm_ioctl.c @@ -573,6 +573,72 @@ EXPORT_SYMBOL(drm_ioctl_permit); #define DRM_LEGACY_IOCTL_DEF(ioctl, _func, _flags) DRM_IOCTL_DEF(ioctl, drm_invalid_op, _flags) #endif
+/** + * drm_handle_set_label_ioctl - Assign a string label to a handle + * @dev: DRM device for the ioctl + * @data: user argument + * @file_priv: drm file-private structure + * + * This is typically targeted at user space drivers to label buffer objects + * with relevant information to provide human readable information about the + * contents of a buffer (for eg: a UBO, command buffer, shader, etc). + * + * Label length *must* not be larger than PAGE_SIZE. + * + * Returns: + * Length of label when setting a label succeeds, negative errno otherwise. + */ + +static int drm_handle_set_label_ioctl(struct drm_device *dev, + void *data, struct drm_file *file_priv) +{ + char *label; + struct drm_handle_label *args = data; + + if (args->len > PAGE_SIZE) + return -EINVAL; + + if (!dev->driver->set_label && !drm_core_check_feature(dev, DRIVER_GEM)) + return -EOPNOTSUPP; + + if (dev->driver->set_label) + return dev->driver->set_label(dev, file_priv, args); + + if (drm_core_check_feature(dev, DRIVER_GEM)) + return drm_gem_set_label(dev, file_priv, args); +} + +/** + * drm_handle_get_label_ioctl - Fetches the label associated with a handle + * @dev: DRM device for the ioctl + * @data: user argument + * @file_priv: drm file-private structure + * + * This is targeted at user space drivers to read back the labels associated + * with a buffer object. You'll need to call this ioctl twice in order to be + * able to read back the entnire label. Optionally, userspace can also read + * back the label partially by passing a + * fixed length in `struct drm_handle_label`. + * + * Returns: + * Length of label copied back to userspace. + */ + +static int drm_handle_get_label_ioctl(struct drm_device *dev, + void *data, struct drm_file *file_priv) +{ + struct drm_handle_label *args = data; + + if (!dev->driver->get_label && !drm_core_check_feature(dev, DRIVER_GEM)) + return -EOPNOTSUPP; + + if (dev->driver->get_label) + return dev->driver->get_label(dev, file_priv, args); + + if (drm_core_check_feature(dev, DRIVER_GEM)) + return drm_gem_get_label(dev, file_priv, args); +} + /* Ioctl table */ static const struct drm_ioctl_desc drm_ioctls[] = { DRM_IOCTL_DEF(DRM_IOCTL_VERSION, drm_version, DRM_RENDER_ALLOW), @@ -715,6 +781,10 @@ static const struct drm_ioctl_desc drm_ioctls[] = { DRM_IOCTL_DEF(DRM_IOCTL_MODE_LIST_LESSEES, drm_mode_list_lessees_ioctl, DRM_MASTER), DRM_IOCTL_DEF(DRM_IOCTL_MODE_GET_LEASE, drm_mode_get_lease_ioctl, DRM_MASTER), DRM_IOCTL_DEF(DRM_IOCTL_MODE_REVOKE_LEASE, drm_mode_revoke_lease_ioctl, DRM_MASTER), + DRM_IOCTL_DEF(DRM_IOCTL_HANDLE_SET_LABEL, drm_handle_set_label_ioctl, + DRM_RENDER_ALLOW), + DRM_IOCTL_DEF(DRM_IOCTL_HANDLE_GET_LABEL, drm_handle_get_label_ioctl, + DRM_RENDER_ALLOW), };
#define DRM_CORE_IOCTL_COUNT ARRAY_SIZE( drm_ioctls ) diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h index bb924cddc09c..6fcb7b9ff322 100644 --- a/include/drm/drm_drv.h +++ b/include/drm/drm_drv.h @@ -540,6 +540,36 @@ struct drm_driver { struct drm_device *dev, uint32_t handle);
+ /** + * @set_label: + * + * Label a buffer object + * + * Called by the user via ioctl. + * + * Returns: + * + * Length of label on success, negative errno on failure. + */ + int (*set_label)(struct drm_device *dev, + struct drm_file *file_priv, + struct drm_handle_label *args); + + /** + * @get_label: + * + * Read the label of a buffer object. + * + * Called by the user via ioctl. + * + * Returns: + * + * Length of label on success, negative errno on failiure. + */ + char *(*get_label)(struct drm_device *dev, + struct drm_file *file_priv, + struct drm_handle_label *args); + /** * @gem_vm_ops: Driver private ops for this object * diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h index 2410ff0a8e86..064b080eb32f 100644 --- a/include/drm/drm_gem.h +++ b/include/drm/drm_gem.h @@ -250,6 +250,13 @@ struct drm_gem_object { */ int name;
+ /** + * @label: + * + * Label for this object, should be a human readable string. + */ + char *label; + /** * @dma_buf: * @@ -311,6 +318,13 @@ struct drm_gem_object { * */ const struct drm_gem_object_funcs *funcs; + + /** + * @bo_lock + * + * Protects buffer object labels + */ + struct mutex bo_lock; };
/** @@ -418,5 +432,10 @@ int drm_gem_dumb_map_offset(struct drm_file *file, struct drm_device *dev, int drm_gem_dumb_destroy(struct drm_file *file, struct drm_device *dev, uint32_t handle); +int drm_gem_set_label(struct drm_device *dev, struct drm_file *file_priv, + struct drm_handle_label *args); +void drm_gem_adopt_label(struct drm_gem_object *gem_obj, const char *label); +int drm_gem_get_label(struct drm_device *dev, struct drm_file *file_priv, + struct drm_handle_label *args);
#endif /* __DRM_GEM_H__ */ diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h index 808b48a93330..2a7128271307 100644 --- a/include/uapi/drm/drm.h +++ b/include/uapi/drm/drm.h @@ -626,6 +626,27 @@ struct drm_gem_open { __u64 size; };
+/** struct drm_handle_label - ioctl argument for labelling BOs. + * + * This label's a BO with a userspace label + * + */ +struct drm_handle_label { + /** Handle for the object being labelled. */ + __u32 handle; + + /** Label and label length (len excludes the trailing NULL). + * Label length *MUST* be smaller than PAGE_SIZE. + * Label length can be smaller than actual length when reading + * the label back. + */ + __u32 len; + __u64 label; + + /** Flags .. Currently no flags are defined */ + __u32 flags; +}; + #define DRM_CAP_DUMB_BUFFER 0x1 #define DRM_CAP_VBLANK_HIGH_CRTC 0x2 #define DRM_CAP_DUMB_PREFERRED_DEPTH 0x3 @@ -947,8 +968,10 @@ extern "C" { #define DRM_IOCTL_SYNCOBJ_QUERY DRM_IOWR(0xCB, struct drm_syncobj_timeline_array) #define DRM_IOCTL_SYNCOBJ_TRANSFER DRM_IOWR(0xCC, struct drm_syncobj_transfer) #define DRM_IOCTL_SYNCOBJ_TIMELINE_SIGNAL DRM_IOWR(0xCD, struct drm_syncobj_timeline_array) - #define DRM_IOCTL_MODE_GETFB2 DRM_IOWR(0xCE, struct drm_mode_fb_cmd2) +#define DRM_IOCTL_HANDLE_SET_LABEL DRM_IOW(0xCF, struct drm_handle_label) +#define DRM_IOCTL_HANDLE_GET_LABEL DRM_IOWR(0xD0, struct drm_handle_label) +
/** * Device specific ioctls should only be in their respective headers