[PATCH 5.15 555/913] selftests/bpf: Fix error reporting from sock_fields programs

From: Greg Kroah-Hartman
Date: Tue Apr 05 2022 - 21:53:39 EST

From: Jakub Sitnicki <jakub@xxxxxxxxxxxxxx>

[ Upstream commit a4c9fe0ed4a13e25e43fcd44d9f89bc19ba8fbb7 ]

The helper macro that records an error in BPF programs that exercise sock
fields access has been inadvertently 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@xxxxxxxxxxxxxx>
Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Acked-by: Martin KaFai Lau <kafai@xxxxxx>
Link: https://lore.kernel.org/bpf/20220317113920.1068535-2-jakub@xxxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
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 81b57b9aaaea..7967348b11af 100644
--- a/tools/testing/selftests/bpf/progs/test_sock_fields.c
+++ b/tools/testing/selftests/bpf/progs/test_sock_fields.c
@@ -113,7 +113,7 @@ 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); \
return CG_OK; \