mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-09-27 12:57:53 +00:00
Code Issues Releases Wiki Activity

libbpf: Fail early when loading programs with unspecified type

Browse source 
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
This commit is contained in:
Andrei Matei 2020-12-02 23:34:10 -05:00 committed by Andrii Nakryiko
parent a8b415c9bd
commit 80b2b5c3a7
1 changed files with 14 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

15
tools/lib/bpf/libbpf.c
View file

@ -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;