From 7078c5eae45a18734b7b8014e95eab90eeea8d9c Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Fri, 23 Apr 2021 11:13:40 -0700 Subject: [PATCH] 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 Signed-off-by: Alexei Starovoitov Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20210423181348.1801389-11-andrii@kernel.org --- src/linker.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/src/linker.c b/src/linker.c index b0e0384..5505c85 100644 --- a/src/linker.c +++ b/src/linker.c @@ -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];