[PATCH 4/6] drm: add timeline syncobj payload query ioctl

[Christian König]

Am 20.09.2018 um 13:03 schrieb Chunming Zhou:
> user mode can query timeline payload.
>
> Signed-off-by: Chunming Zhou <david1.zhou at amd.com>
> ---
>   drivers/gpu/drm/drm_internal.h |  2 ++
>   drivers/gpu/drm/drm_ioctl.c    |  2 ++
>   drivers/gpu/drm/drm_syncobj.c  | 53 ++++++++++++++++++++++++++++++++++
>   include/uapi/drm/drm.h         | 11 +++++++
>   4 files changed, 68 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_internal.h b/drivers/gpu/drm/drm_internal.h
> index 566d44e3c782..9c4826411a3c 100644
> --- a/drivers/gpu/drm/drm_internal.h
> +++ b/drivers/gpu/drm/drm_internal.h
> @@ -189,6 +189,8 @@ int drm_syncobj_reset_ioctl(struct drm_device *dev, void *data,
>   			    struct drm_file *file_private);
>   int drm_syncobj_signal_ioctl(struct drm_device *dev, void *data,
>   			     struct drm_file *file_private);
> +int drm_syncobj_query_ioctl(struct drm_device *dev, void *data,
> +			    struct drm_file *file_private);
>   
>   /* drm_framebuffer.c */
>   void drm_framebuffer_print_info(struct drm_printer *p, unsigned int indent,
> diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c
> index c0891614f516..c3c0617e6372 100644
> --- a/drivers/gpu/drm/drm_ioctl.c
> +++ b/drivers/gpu/drm/drm_ioctl.c
> @@ -675,6 +675,8 @@ static const struct drm_ioctl_desc drm_ioctls[] = {
>   		      DRM_UNLOCKED|DRM_RENDER_ALLOW),
>   	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_SIGNAL, drm_syncobj_signal_ioctl,
>   		      DRM_UNLOCKED|DRM_RENDER_ALLOW),
> +	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_QUERY, drm_syncobj_query_ioctl,
> +		      DRM_UNLOCKED|DRM_RENDER_ALLOW),
>   	DRM_IOCTL_DEF(DRM_IOCTL_CRTC_GET_SEQUENCE, drm_crtc_get_sequence_ioctl, DRM_UNLOCKED),
>   	DRM_IOCTL_DEF(DRM_IOCTL_CRTC_QUEUE_SEQUENCE, drm_crtc_queue_sequence_ioctl, DRM_UNLOCKED),
>   	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATE_LEASE, drm_mode_create_lease_ioctl, DRM_MASTER|DRM_UNLOCKED),
> diff --git a/drivers/gpu/drm/drm_syncobj.c b/drivers/gpu/drm/drm_syncobj.c
> index a43de0e4616c..e998fc319f9f 100644
> --- a/drivers/gpu/drm/drm_syncobj.c
> +++ b/drivers/gpu/drm/drm_syncobj.c
> @@ -1289,3 +1289,56 @@ drm_syncobj_signal_ioctl(struct drm_device *dev, void *data,
>   
>   	return ret;
>   }
> +
> +static void drm_syncobj_timeline_query_payload(struct drm_syncobj *syncobj,
> +					       uint64_t *point)
> +{
> +	if (syncobj->type != DRM_SYNCOBJ_TYPE_TIMELINE) {
> +		DRM_ERROR("Normal syncobj cann't be queried!");
> +		*point = 0;
> +		return;
> +	}
> +	*point = syncobj->signal_point;
> +}
> +
> +int drm_syncobj_query_ioctl(struct drm_device *dev, void *data,
> +			    struct drm_file *file_private)
> +{
> +	struct drm_syncobj_timeline_query *args = data;
> +	struct drm_syncobj **syncobjs;
> +	uint64_t *points;
> +	uint32_t i;
> +	int ret;
> +
> +	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
> +		return -ENODEV;
> +
> +	if (args->count_handles == 0)
> +		return -EINVAL;
> +
> +	ret = drm_syncobj_array_find(file_private,
> +				     u64_to_user_ptr(args->handles),
> +				     args->count_handles,
> +				     &syncobjs);
> +	if (ret < 0)
> +		return ret;
> +
> +
> +	points = kmalloc_array(args->count_handles, sizeof(*points),
> +			       GFP_KERNEL);
> +	if (points == NULL) {
> +		ret = -ENOMEM;
> +		goto out;
> +	}
> +	for (i = 0; i < args->count_handles; i++) {
> +		drm_syncobj_timeline_query_payload(syncobjs[i], &points[i]);
> +		copy_to_user(u64_to_user_ptr(args->points), points,
> +			     sizeof(uint64_t) * args->count_handles);

Copying the points to userspace on each iteration of the loop? That 
doesn't looks correct to me.

Additional to that you need to check the return value of copy_to_user.

Regards,
Christian.

> +	}
> +
> +	kfree(points);
> +out:
> +	drm_syncobj_array_free(syncobjs, args->count_handles);
> +
> +	return ret;
> +}
> diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h
> index 501e86d81f47..188b63f1975b 100644
> --- a/include/uapi/drm/drm.h
> +++ b/include/uapi/drm/drm.h
> @@ -767,6 +767,15 @@ struct drm_syncobj_array {
>   	__u32 pad;
>   };
>   
> +struct drm_syncobj_timeline_query {
> +	__u64 handles;
> +	/* points are timeline syncobjs payloads returned by query ioctl */
> +	__u64 points;
> +	__u32 count_handles;
> +	__u32 pad;
> +};
> +
> +
>   /* Query current scanout sequence number */
>   struct drm_crtc_get_sequence {
>   	__u32 crtc_id;		/* requested crtc_id */
> @@ -924,6 +933,8 @@ extern "C" {
>   #define DRM_IOCTL_MODE_REVOKE_LEASE	DRM_IOWR(0xC9, struct drm_mode_revoke_lease)
>   
>   #define DRM_IOCTL_SYNCOBJ_TIMELINE_WAIT	DRM_IOWR(0xCA, struct drm_syncobj_timeline_wait)
> +#define DRM_IOCTL_SYNCOBJ_QUERY		DRM_IOWR(0xCB, struct drm_syncobj_timeline_query)
> +
>   /**
>    * Device specific ioctls should only be in their respective headers
>    * The device specific ioctl range is from 0x40 to 0x9f.