diff options
| author | Tony Ambardar <tony.ambardar@gmail.com> | 2020-09-19 22:01:35 -0700 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2020-09-21 21:50:49 +0200 |
| commit | 1245008122d7311683d70c05b2eea167a314fb5f (patch) | |
| tree | fb3854c517928306ff686f114caa7eafc6e07d75 | |
| parent | 65c204398928f9c79f1a29912b410439f7052635 (diff) | |
libbpf: Fix native endian assumption when parsing BTF
Code in btf__parse_raw() fails to detect raw BTF of non-native endianness
and assumes it must be ELF data, which then fails to parse as ELF and
yields a misleading error message:
root:/# bpftool btf dump file /sys/kernel/btf/vmlinux
libbpf: failed to get EHDR from /sys/kernel/btf/vmlinux
For example, this could occur after cross-compiling a BTF-enabled kernel
for a target with non-native endianness, which is currently unsupported.
Check for correct endianness and emit a clearer error message:
root:/# bpftool btf dump file /sys/kernel/btf/vmlinux
libbpf: non-native BTF endianness is not supported
Fixes: 94a1fedd63ed ("libbpf: Add btf__parse_raw() and generic btf__parse() APIs")
Signed-off-by: Tony Ambardar <Tony.Ambardar@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/90f81508ecc57bc0da318e0fe0f45cfe49b17ea7.1600417359.git.Tony.Ambardar@gmail.com
| -rw-r--r-- | tools/lib/bpf/btf.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c index 7dfca7016aaa..6bdbc389b493 100644 --- a/tools/lib/bpf/btf.c +++ b/tools/lib/bpf/btf.c @@ -659,6 +659,12 @@ struct btf *btf__parse_raw(const char *path) err = -EIO; goto err_out; } + if (magic == __bswap_16(BTF_MAGIC)) { + /* non-native endian raw BTF */ + pr_warn("non-native BTF endianness is not supported\n"); + err = -LIBBPF_ERRNO__ENDIAN; + goto err_out; + } if (magic != BTF_MAGIC) { /* definitely not a raw BTF */ err = -EPROTO; |