On Fri, Feb 25, 2022 at 12:13 PM -08, Martin KaFai Lau wrote:

On Fri, Feb 25, 2022 at 07:41:30PM +0100, Jakub Sitnicki wrote:

quoted

The helper macro that records an error in BPF programs that exercise sock
fields access has been indavertedly broken by adaptation work that happened
in commit b18c1f0aa477 ("bpf: selftest: Adapt sock_fields test to use skel
and global variables").

BPF_NOEXIST flag cannot be used to update BPF_MAP_TYPE_ARRAY. The operation
always fails with -EEXIST, which in turn means the error never gets
recorded, and the checks for errors always pass.

Revert the change in update flags.

Fixes: b18c1f0aa477 ("bpf: selftest: Adapt sock_fields test to use skel and global variables")
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
---
 tools/testing/selftests/bpf/progs/test_sock_fields.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/bpf/progs/test_sock_fields.c b/tools/testing/selftests/bpf/progs/test_sock_fields.c
index 246f1f001813..3e2e3ee51cc9 100644
--- a/tools/testing/selftests/bpf/progs/test_sock_fields.c
+++ b/tools/testing/selftests/bpf/progs/test_sock_fields.c

@@ -114,7 +114,7 @@ static void tpcpy(struct bpf_tcp_sock *dst,
 
 #define RET_LOG() ({						\
 	linum = __LINE__;					\
-	bpf_map_update_elem(&linum_map, &linum_idx, &linum, BPF_NOEXIST);	\
+	bpf_map_update_elem(&linum_map, &linum_idx, &linum, BPF_ANY);	\

Acked-by: Martin KaFai Lau <redacted>

Thanks for the quick review.

I need to follow up with a v2. Was too quick to send this patch out by
itself. Now that the error reporting works, the test sock_fields tests
are failing on little- and big-endian.