Messages in this thread | | | Subject | Re: [PATCH] selftests/bpf: Fix return value check in attach_bpf() | From | "yukuai (C)" <> | Date | Sat, 29 May 2021 09:25:28 +0800 |
| |
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@huawei.com> >> Signed-off-by: Yu Kuai <yukuai3@huawei.com> >> --- >> 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 > . >
| |