Al Viro
2021-May-20 06:28 UTC
[PATCH v7 11/12] vduse: Introduce VDUSE - vDPA Device in Userspace
On Mon, May 17, 2021 at 05:55:12PM +0800, Xie Yongji wrote:> + case VDUSE_IOTLB_GET_FD: { > + struct vduse_iotlb_entry entry; > + struct vhost_iotlb_map *map; > + struct vdpa_map_file *map_file; > + struct vduse_iova_domain *domain = dev->domain; > + struct file *f = NULL; > + > + ret = -EFAULT; > + if (copy_from_user(&entry, argp, sizeof(entry))) > + break;return -EFAULT; surely?> + > + ret = -EINVAL; > + if (entry.start > entry.last) > + break;... and similar here, etc.> + spin_lock(&domain->iotlb_lock); > + map = vhost_iotlb_itree_first(domain->iotlb, > + entry.start, entry.last); > + if (map) { > + map_file = (struct vdpa_map_file *)map->opaque; > + f = get_file(map_file->file); > + entry.offset = map_file->offset; > + entry.start = map->start; > + entry.last = map->last; > + entry.perm = map->perm; > + } > + spin_unlock(&domain->iotlb_lock); > + ret = -EINVAL; > + if (!f) > + break; > + > + ret = -EFAULT; > + if (copy_to_user(argp, &entry, sizeof(entry))) { > + fput(f); > + break; > + } > + ret = receive_fd(f, perm_to_file_flags(entry.perm)); > + fput(f); > + break;IDGI. The main difference between receive_fd() and plain old get_unused_fd_flags() + fd_install() is __receive_sock() call. Which does nothing whatsoever in case of non-sockets. Can you get a socket here? IOW, why bother with that crap at all, nevermind exporting it?