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> > u64 size; > > + u64 seals:8; > > Kernel uABI defines seals as unsigned int, I think we can spare u32 for > them and reserve a u32 flags for other memfd flags (MFD_CLOEXEC, > MFD_HUGETLB etc). It is a bit worse than that, the "v2" version is only going to support some set of seals (probably the set defined in v6.19) and if there are new seals down the road then this needs a version bump. So I'd check that only supported seals are set here: > > + seals = memfd_get_seals(args->file); > > + if (seals < 0) { > > + err = seals; > > + goto err_free_ser; > > + } > > + > > ser->pos = args->file->f_pos; > > ser->size = i_size_read(inode); > > + ser->seals = seals; .. > > @@ -444,13 +453,23 @@ static int memfd_luo_retrieve(struct liveupdate_file_op_args *args) > > if (!ser) > > return -EINVAL; > > > > - file = memfd_alloc_file("", 0); > > + /* > > + * The seals are preserved. Allow sealing here so they can be added > > + * later. > > + */ > > + file = memfd_alloc_file("", MFD_ALLOW_SEALING); > > if (IS_ERR(file)) { > > pr_err("failed to setup file: %pe\n", file); > > err = PTR_ERR(file); > > goto free_ser; > > } > > > > + err = memfd_add_seals(file, ser->seals); Because we really don't want this to fail :\ Jason