diff options
| author | Kumar Kartikeya Dwivedi <memxor@gmail.com> | 2021-09-30 11:46:34 +0530 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2021-09-30 23:19:58 +0200 |
| commit | 4729445b47efebf089da4ccbcd1b116ffa2ad4af (patch) | |
| tree | 8fa20005d2ae841947ba85bfe90ca4ccdd73c875 | |
| parent | 30e29a9a2bc6a4888335a6ede968b75cd329657a (diff) | |
libbpf: Fix segfault in light skeleton for objects without BTF
When fed an empty BPF object, bpftool gen skeleton -L crashes at
btf__set_fd() since it assumes presence of obj->btf, however for
the sequence below clang adds no .BTF section (hence no BTF).
Reproducer:
$ touch a.bpf.c
$ clang -O2 -g -target bpf -c a.bpf.c
$ bpftool gen skeleton -L a.bpf.o
/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
/* THIS FILE IS AUTOGENERATED! */
struct a_bpf {
struct bpf_loader_ctx ctx;
Segmentation fault (core dumped)
The same occurs for files compiled without BTF info, i.e. without
clang's -g flag.
Fixes: 67234743736a (libbpf: Generate loader program out of BPF ELF file.)
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210930061634.1840768-1-memxor@gmail.com
| -rw-r--r-- | tools/lib/bpf/libbpf.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 88d8825fc6f6..e4f83c304ec9 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -6894,7 +6894,8 @@ int bpf_object__load_xattr(struct bpf_object_load_attr *attr) if (obj->gen_loader) { /* reset FDs */ - btf__set_fd(obj->btf, -1); + if (obj->btf) + btf__set_fd(obj->btf, -1); for (i = 0; i < obj->nr_maps; i++) obj->maps[i].fd = -1; if (!err) |