diff options
| author | Andrei Matei <andreimatei1@gmail.com> | 2020-12-02 23:34:10 -0500 |
|---|---|---|
| committer | Andrii Nakryiko <andrii@kernel.org> | 2020-12-03 11:37:05 -0800 |
| commit | 80b2b5c3a701d56de98d00d99bc9cc384fb316d9 (patch) | |
| tree | de3e4fcc2771f5974b06446cb2decd09c28ebf22 /tools/lib/bpf/libbpf.c | |
| parent | a8b415c9bde69dc194e57db8c27cb96908b30aca (diff) | |
libbpf: Fail early when loading programs with unspecified type
Before this patch, a program with unspecified type
(BPF_PROG_TYPE_UNSPEC) would be passed to the BPF syscall, only to have
the kernel reject it with an opaque invalid argument error. This patch
makes libbpf reject such programs with a nicer error message - in
particular libbpf now tries to diagnose bad ELF section names at both
open time and load time.
Signed-off-by: Andrei Matei <andreimatei1@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20201203043410.59699-1-andreimatei1@gmail.com
Diffstat (limited to 'tools/lib/bpf/libbpf.c')
| -rw-r--r-- | tools/lib/bpf/libbpf.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 313034117070..d6f45538444d 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -6629,6 +6629,16 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt, char *log_buf = NULL; int btf_fd, ret; + if (prog->type == BPF_PROG_TYPE_UNSPEC) { + /* + * The program type must be set. Most likely we couldn't find a proper + * section definition at load time, and thus we didn't infer the type. + */ + pr_warn("prog '%s': missing BPF prog type, check ELF section name '%s'\n", + prog->name, prog->sec_name); + return -EINVAL; + } + if (!insns || !insns_cnt) return -EINVAL; @@ -6920,9 +6930,12 @@ __bpf_object__open(const char *path, const void *obj_buf, size_t obj_buf_sz, bpf_object__for_each_program(prog, obj) { prog->sec_def = find_sec_def(prog->sec_name); - if (!prog->sec_def) + if (!prog->sec_def) { /* couldn't guess, but user might manually specify */ + pr_debug("prog '%s': unrecognized ELF section name '%s'\n", + prog->name, prog->sec_name); continue; + } if (prog->sec_def->is_sleepable) prog->prog_flags |= BPF_F_SLEEPABLE; |