From a13c0ff6c4b21862f115b751e3cf874f18a5ac2c Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Mon, 6 Dec 2021 17:31:53 +0800 Subject: [PATCH] libbpf: Allow loading empty BTFs stable inclusion from stable-5.10.80 commit 255eb8f8affd23a37c8823c167da9f9e9ad416d0 bugzilla: 185821 https://gitee.com/openeuler/kernel/issues/I4L7CG Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=255eb8f8affd23a37c8823c167da9f9e9ad416d0 -------------------------------- [ Upstream commit b8d52264df85ec12f370c0a8b28d0ac59a05877a ] 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: d8123624506c ("libbpf: Fix BTF data layout checks and allow empty BTF") Reported-by: Christopher William Snowhill Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20210110070341.1380086-2-andrii@kernel.org Signed-off-by: Sasha Levin Signed-off-by: Chen Jun Reviewed-by: Weilong Chen Acked-by: Weilong Chen Signed-off-by: Chen Jun Signed-off-by: Zheng Zengkai --- tools/lib/bpf/btf.c | 5 ----- 1 file changed, 5 deletions(-) diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c index 987c1515b828..c8c751265e23 100644 --- a/tools/lib/bpf/btf.c +++ b/tools/lib/bpf/btf.c @@ -210,11 +210,6 @@ 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; -- GitLab