From: Ben Olson <matthew.olson@intel.com>
Date: Tue, 26 Nov 2024 20:08:45 +0000 (-0600)
Subject: libbpf: Improve debug message when the base BTF cannot be found
X-Git-Tag: v6.14-rc1~133^2~63
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=9a17db586d722c0875f7a0580c438dc80afee1e7;p=linux-block.git

libbpf: Improve debug message when the base BTF cannot be found

When running `bpftool` on a kernel module installed in `/lib/modules...`,
this error is encountered if the user does not specify `--base-btf` to
point to a valid base BTF (e.g. usually in `/sys/kernel/btf/vmlinux`).
However, looking at the debug output to determine the cause of the error
simply says `Invalid BTF string section`, which does not point to the
actual source of the error. This just improves that debug message to tell
users what happened.

Signed-off-by: Ben Olson <matthew.olson@intel.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/Z0YqzQ5lNz7obQG7@bolson-desk
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---

diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index 12468ae0d573..a4ae2df68b91 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -283,7 +283,7 @@ static int btf_parse_str_sec(struct btf *btf)
 		return -EINVAL;
 	}
 	if (!btf->base_btf && start[0]) {
-		pr_debug("Invalid BTF string section\n");
+		pr_debug("Malformed BTF string section, did you forget to provide base BTF?\n");
 		return -EINVAL;
 	}
 	return 0;