libbpf: Allow loading empty BTFs

Empty BTFs do come up (e.g., simple kernel modules with no new types and
strings, compared to the vmlinux BTF) and there is nothing technically wrong
with them. So remove unnecessary check preventing loading empty BTFs.

Fixes: d812362450 ("libbpf: Fix BTF data layout checks and allow empty BTF")
Reported-by: Christopher William Snowhill <chris@kode54.net>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210110070341.1380086-2-andrii@kernel.org
This commit is contained in:
Andrii Nakryiko 2021-01-09 23:03:41 -08:00 committed by Daniel Borkmann
parent bcc5e6162d
commit b8d52264df

View File

@ -240,11 +240,6 @@ static int btf_parse_hdr(struct btf *btf)
}
meta_left = btf->raw_size - sizeof(*hdr);
if (!meta_left) {
pr_debug("BTF has no data\n");
return -EINVAL;
}
if (meta_left < hdr->str_off + hdr->str_len) {
pr_debug("Invalid BTF total size:%u\n", btf->raw_size);
return -EINVAL;