[PATCH v4] drm/ioctl: Add a ioctl to label GEM objects
Boris Brezillon
boris.brezillon at collabora.com
Fri Oct 11 17:31:46 UTC 2019
Hello Rohan,
On Fri, 11 Oct 2019 16:30:09 +0200
Rohan Garg <rohan.garg at collabora.com> wrote:
> DRM_IOCTL_DUMB_SET_LABEL lets you label GEM objects, making it
> easier to debug issues in userspace applications.
>
> 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
>
> Signed-off-by: Rohan Garg <rohan.garg at collabora.com>
> ---
> drivers/gpu/drm/drm_gem.c | 70 ++++++++++++++++++++++++++++++++++
> drivers/gpu/drm/drm_internal.h | 8 ++++
> drivers/gpu/drm/drm_ioctl.c | 1 +
> include/drm/drm_drv.h | 16 ++++++++
> include/drm/drm_gem.h | 7 ++++
> include/uapi/drm/drm.h | 20 ++++++++++
> 6 files changed, 122 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
> index 6854f5867d51..0fa4609b2817 100644
> --- a/drivers/gpu/drm/drm_gem.c
> +++ b/drivers/gpu/drm/drm_gem.c
> @@ -941,6 +941,71 @@ drm_gem_release(struct drm_device *dev, struct drm_file *file_private)
> idr_destroy(&file_private->object_idr);
> }
>
> +int drm_dumb_set_label_ioctl(struct drm_device *dev,
Why dumb? Not sure what a smart set_label_ioctl() function would
do differently :-).
Oh, and if this function can be used to label TTM BOs it should be moved
somewhere else (drm_ioctl.c ?).
> + void *data, struct drm_file *file_priv)
Indentation is broken here.
> +{
> + char *label;
> + struct drm_dumb_set_label_object *args = data;
> + int ret = 0;
> +
> + if (!args->len || !args->name)
Hm, I thought args->len == 0 was a valid case and meant "free the
existing label". Has it changed. The case that's not allowed is
args->len && !args->name.
> + return -EINVAL;
> +
> + if (!dev->driver->label)
> + return -EOPNOTSUPP;
> +
> + label = strndup_user(u64_to_user_ptr(args->name), args->len);
> +
Remove this blank line.
> + if (IS_ERR(label)) {
> + ret = PTR_ERR(label);
> + goto err;
> + }
> +
> + ret = dev->driver->label(dev, file_priv, args->handle, label);
> +
> +err:
I would s/err/out/ as this is not an error-only path.
> + kfree(label);
> + return ret;
> +}
> +
> +int drm_gem_set_label(struct drm_device *dev,
> + struct drm_file *file_priv,
> + uint32_t handle,
> + const char *label)
> +{
> + struct drm_gem_object *gem_obj;
> + int ret = 0;
> +
> + gem_obj = drm_gem_object_lookup(file_priv, handle);
> + if (!gem_obj) {
> + DRM_DEBUG("Failed to look up GEM BO %d\n", handle);
> + ret = -ENOENT;
> + goto err;
> + }
> + drm_gem_adopt_label(gem_obj, label);
> +
> +err:
Ditto: s/err/out/
> + drm_gem_object_put_unlocked(gem_obj);
> + return ret;
> +}
> +EXPORT_SYMBOL(drm_gem_set_label);
> +
> +void drm_gem_adopt_label(struct drm_gem_object *gem_obj, const char *label)
> +{
> + char *adopted_label = NULL;
> +
> + if (label)
> + adopted_label = kstrdup(label, GFP_KERNEL);
Add
WARN_ON(adopted_label);
> +
> + if (gem_obj->label) {
> + kfree(gem_obj->label);
> + gem_obj->label = NULL;
This assignment is useless since gem_obj->label is assigned below.
> + }
> +
> + gem_obj->label = adopted_label;
> +}
> +EXPORT_SYMBOL(drm_gem_adopt_label);
> +
> /**
> * drm_gem_object_release - release GEM buffer object resources
> * @obj: GEM buffer object
> @@ -958,6 +1023,11 @@ drm_gem_object_release(struct drm_gem_object *obj)
>
> dma_resv_fini(&obj->_resv);
> drm_gem_free_mmap_offset(obj);
> +
> + if (obj->label) {
> + kfree(obj->label);
> + obj->label = NULL;
> + }
You can call kfree(obj->label) directly (kfree() checks for NULL vals),
and no need to reset obj->label (obj should be free when the function
returns).
> }
> EXPORT_SYMBOL(drm_gem_object_release);
>
> diff --git a/drivers/gpu/drm/drm_internal.h b/drivers/gpu/drm/drm_internal.h
> index 51a2055c8f18..cbc3f7b7fb9b 100644
> --- a/drivers/gpu/drm/drm_internal.h
> +++ b/drivers/gpu/drm/drm_internal.h
> @@ -137,6 +137,14 @@ 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_dumb_set_label_ioctl(struct drm_device *dev,
> + void *data,
> + struct drm_file *file_priv);
> +int drm_gem_set_label(struct drm_device *dev,
> + struct drm_file *file_priv,
> + uint32_t handle,
> + const char *label);
> +void drm_gem_adopt_label(struct drm_gem_object *gem_obj, const char *label);
>
> /* 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 fcd728d7cf72..f34e1571d70f 100644
> --- a/drivers/gpu/drm/drm_ioctl.c
> +++ b/drivers/gpu/drm/drm_ioctl.c
> @@ -714,6 +714,7 @@ 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_DUMB_SET_LABEL, drm_dumb_set_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 cf13470810a5..501a3924354a 100644
> --- a/include/drm/drm_drv.h
> +++ b/include/drm/drm_drv.h
> @@ -715,6 +715,22 @@ struct drm_driver {
> struct drm_device *dev,
> uint32_t handle);
>
> + /**
> + * @label:
> + *
> + * This label's a buffer object.
> + *
> + * Called by the user via ioctl.
> + *
> + * Returns:
> + *
> + * Zero on success, negative errno on failure.
> + */
> + int (*label)(struct drm_device *dev,
Maybe label_bo or set_bo_label instead of just label, just to make it
clear that the label is applied to a buffer object.
> + struct drm_file *file_priv,
> + uint32_t handle,
> + char *label);
Indentation issue here as well.
> +
> /**
> * @gem_vm_ops: Driver private ops for this object
> *
> diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h
> index 6aaba14f5972..f801c054e972 100644
> --- a/include/drm/drm_gem.h
> +++ b/include/drm/drm_gem.h
> @@ -237,6 +237,13 @@ struct drm_gem_object {
> */
> int name;
>
> + /**
> + * @label:
> + *
> + * Label for this object, should be a human readable string.
> + */
> + char *label;
> +
> /**
> * @dma_buf:
> *
> diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h
> index 8a5b2f8f8eb9..309c3c091385 100644
> --- a/include/uapi/drm/drm.h
> +++ b/include/uapi/drm/drm.h
> @@ -626,6 +626,25 @@ struct drm_gem_open {
> __u64 size;
> };
>
> +/** struct drm_dumb_set_label_object - ioctl argument for labelling BOs.
> + *
> + * This label's a BO with a userspace label
> + *
> + */
> +struct drm_dumb_set_label_object {
> + /** Handle for the object being labelled. */
> + __u32 handle;
> +
> + /** Label and label length.
> + * len includes the trailing NUL.
> + */
Nitpick: the comment fits on a single line.
/** Label and label length (len includes the trailing NUL). */
> + __u32 len;
> + __u64 name;
> +
> + /** Flags */
> + int flags;
> +};
> +
> #define DRM_CAP_DUMB_BUFFER 0x1
> #define DRM_CAP_VBLANK_HIGH_CRTC 0x2
> #define DRM_CAP_DUMB_PREFERRED_DEPTH 0x3
> @@ -946,6 +965,7 @@ 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_DUMB_SET_LABEL DRM_IOWR(0xCE, struct drm_dumb_set_label_object)
Maybe s/DRM_IOCTL_DUMB_SET_LABEL/DRM_IOCTL_SET_BO_LABEL/ and
s/drm_dumb_set_label_object/drm_set_bo_label/
>
> /**
> * Device specific ioctls should only be in their respective headers
More information about the dri-devel
mailing list