virtio-gpu: fix ioctl and expose the fixed status to userspace.

[mirror_ubuntu-bionic-kernel.git] / drivers / gpu / drm / virtio / virtgpu_ioctl.c

diff --git a/drivers/gpu/drm/virtio/virtgpu_ioctl.c b/drivers/gpu/drm/virtio/virtgpu_ioctl.c
index 0528edb4a2bfe0ed9f2a5d8a272b1b1af8c284cd..8540b44506b05f855d05cd4cad4b7abf5d379dda 100644 (file)
--- a/drivers/gpu/drm/virtio/virtgpu_ioctl.c
+++ b/drivers/gpu/drm/virtio/virtgpu_ioctl.c
@@ -196,6 +196,9 @@ static int virtio_gpu_getparam_ioctl(struct drm_device *dev, void *data,
        case VIRTGPU_PARAM_3D_FEATURES:
                value = vgdev->has_virgl_3d == true ? 1 : 0;
                break;
+       case VIRTGPU_PARAM_CAPSET_QUERY_FIX:
+               value = 1;
+               break;
        default:
                return -EINVAL;
        }
@@ -471,7 +474,7 @@ static int virtio_gpu_get_caps_ioctl(struct drm_device *dev,
 {
        struct virtio_gpu_device *vgdev = dev->dev_private;
        struct drm_virtgpu_get_caps *args = data;
-       int size;
+       unsigned size, host_caps_size;
        int i;
        int found_valid = -1;
        int ret;
@@ -480,6 +483,10 @@ static int virtio_gpu_get_caps_ioctl(struct drm_device *dev,
        if (vgdev->num_capsets == 0)
                return -ENOSYS;
 
+       /* don't allow userspace to pass 0 */
+       if (args->size == 0)
+               return -EINVAL;
+
        spin_lock(&vgdev->display_info_lock);
        for (i = 0; i < vgdev->num_capsets; i++) {
                if (vgdev->capsets[i].id == args->cap_set_id) {
@@ -495,11 +502,9 @@ static int virtio_gpu_get_caps_ioctl(struct drm_device *dev,
                return -EINVAL;
        }
 
-       size = vgdev->capsets[found_valid].max_size;
-       if (args->size > size) {
-               spin_unlock(&vgdev->display_info_lock);
-               return -EINVAL;
-       }
+       host_caps_size = vgdev->capsets[found_valid].max_size;
+       /* only copy to user the minimum of the host caps size or the guest caps size */
+       size = min(args->size, host_caps_size);
 
        list_for_each_entry(cache_ent, &vgdev->cap_cache, head) {
                if (cache_ent->id == args->cap_set_id &&