On Thu, Aug 28, 2025 at 1:15 AM Feng Yang yangfeng59949@163.com wrote:
From: Feng Yang yangfeng@kylinos.cn
The error message printed here only uses the previous err value, which results in it being printed as 0. When bpf_map__attach_struct_ops encounters an error, it uses libbpf_err_ptr(err) to set errno = -err and returns NULL.
Yes, but libbpf_get_error() is better. And decimal number is preferred as ASSERT_OK_PTR() macro does.
pw-bot: cr
Therefore, strerror(errno) can be used to fix this issue.
Fix before: run_subtest:FAIL:1019 bpf_map__attach_struct_ops failed for map pro_epilogue: err=0
Fix after: run_subtest:FAIL:1019 bpf_map__attach_struct_ops failed for map pro_epilogue: Bad file descriptor
Signed-off-by: Feng Yang yangfeng@kylinos.cn
tools/testing/selftests/bpf/test_loader.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/bpf/test_loader.c b/tools/testing/selftests/bpf/test_loader.c index f361c8aa1daf..686a7d7f87b1 100644 --- a/tools/testing/selftests/bpf/test_loader.c +++ b/tools/testing/selftests/bpf/test_loader.c @@ -1008,8 +1008,8 @@ void run_subtest(struct test_loader *tester, } link = bpf_map__attach_struct_ops(map); if (!link) {
PRINT_FAIL("bpf_map__attach_struct_ops failed for map %s: err=%d\n",bpf_map__name(map), err);
PRINT_FAIL("bpf_map__attach_struct_ops failed for map %s: %s\n",bpf_map__name(map), strerror(errno)); goto tobj_cleanup; } links[links_cnt++] = link;-- 2.27.0