[PATCH v3 1/2] libbpf: show error info about missing ".BTF" section

[Changbin Du]

Show the real problem instead of just saying "No such file or directory".

Now will print below info:
libbpf: failed to find '.BTF' ELF section in /home/changbin/work/linux/vmlinux
Error: failed to load BTF from /home/changbin/work/linux/vmlinux: No such file or directory

Signed-off-by: Changbin Du <changbin.du@xxxxxxxxx>
---
 tools/lib/bpf/btf.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index 71e165b09ed5..dd2badf1a54e 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -990,6 +990,7 @@ static struct btf *btf_parse_elf(const char *path, struct btf *base_btf,
 	err = 0;
 
 	if (!btf_data) {
+		pr_warn("failed to find '%s' ELF section in %s\n", BTF_ELF_SEC, path);
 		err = -ENOENT;
 		goto done;
 	}
-- 
2.37.2