libbpf: Tighten BTF type ID rewriting with error checking

It should never fail, but if it does, it's better to know about this rather
than end up with nonsensical type IDs.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210423181348.1801389-11-andrii@kernel.org
This commit is contained in:
Andrii Nakryiko 2021-04-23 11:13:40 -07:00 committed by Alexei Starovoitov
parent 386b1d241e
commit 83a157279f
1 changed files with 7 additions and 0 deletions

View File

@ -1429,6 +1429,13 @@ static int linker_fixup_btf(struct src_obj *obj)
static int remap_type_id(__u32 *type_id, void *ctx)
{
int *id_map = ctx;
int new_id = id_map[*type_id];
/* Error out if the type wasn't remapped. Ignore VOID which stays VOID. */
if (new_id == 0 && *type_id != 0) {
pr_warn("failed to find new ID mapping for original BTF type ID %u\n", *type_id);
return -EINVAL;
}
*type_id = id_map[*type_id];