On 2021/05/29 4:46, Daniel Borkmann wrote:
On 5/28/21 11:07 AM, Yu Kuai wrote:
use libbpf_get_error() to check the return value of
bpf_program__attach().
Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
---
tools/testing/selftests/bpf/benchs/bench_rename.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/bpf/benchs/bench_rename.c
b/tools/testing/selftests/bpf/benchs/bench_rename.c
index c7ec114eca56..b7d4a1d74fca 100644
--- a/tools/testing/selftests/bpf/benchs/bench_rename.c
+++ b/tools/testing/selftests/bpf/benchs/bench_rename.c
@@ -65,7 +65,7 @@ static void attach_bpf(struct bpf_program *prog)
struct bpf_link *link;
link = bpf_program__attach(prog);
- if (!link) {
+ if (libbpf_get_error(link)) {
fprintf(stderr, "failed to attach program!\n");
exit(1);
}
Could you explain the rationale of this patch? bad2e478af3b
("selftests/bpf: Turn
on libbpf 1.0 mode and fix all IS_ERR checks") explains: 'Fix all the
explicit
IS_ERR checks that now will be broken because libbpf returns NULL on
error (and
sets errno).' So the !link check looks totally reasonable to me.
Converting to
libbpf_get_error() is not wrong in itself, but given you don't make any
use of
the err code, there is also no point in this diff here.
Hi,
I was thinking that bpf_program__attach() can return error code
theoretically(for example -ESRCH), and such case need to be handled.
Thanks,
Yu Kuai
Thanks,
Daniel
.
