Similar to the fix in commit:
e31eec77e4ab (bpf: selftests: Fix fd cleanup in get_branch_snapshot)
We use memset to set fds to -1 without breaking on future changes to
the array size (when MAX_SERVER constant is bumped).
The particular close(0) occurs on non-reuseport tests, so it can be seen
with -n 115/{2,3} but not 115/4. This can cause problems with future
tests if they depend on BTF fd never being acquired as fd 0, breaking
internal libbpf assumptions.
Cc: Jakub Sitnicki <jakub@xxxxxxxxxxxxxx>
Fixes: 0ab5539f8584 (selftests/bpf: Tests for BPF_SK_LOOKUP attach point)
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx>
---
.../selftests/bpf/prog_tests/sk_lookup.c | 20 +++++++++++++------
1 file changed, 14 insertions(+), 6 deletions(-)
diff --git a/tools/testing/selftests/bpf/prog_tests/sk_lookup.c b/tools/testing/selftests/bpf/prog_tests/sk_lookup.c
index aee41547e7f4..572220065bdf 100644
--- a/tools/testing/selftests/bpf/prog_tests/sk_lookup.c
+++ b/tools/testing/selftests/bpf/prog_tests/sk_lookup.c
@@ -598,11 +598,14 @@ static void query_lookup_prog(struct test_sk_lookup *skel)
static void run_lookup_prog(const struct test *t)
{
- int server_fds[MAX_SERVERS] = { -1 };
int client_fd, reuse_conn_fd = -1;
struct bpf_link *lookup_link;
+ int server_fds[MAX_SERVERS];
int i, err;
+ /* set all fds to -1 */
+ memset(server_fds, 0xFF, sizeof(server_fds));
+
lookup_link = attach_lookup_prog(t->lookup_prog);
if (!lookup_link)
return;
@@ -663,8 +666,9 @@ static void run_lookup_prog(const struct test *t)
if (reuse_conn_fd != -1)
close(reuse_conn_fd);
for (i = 0; i < ARRAY_SIZE(server_fds); i++) {
- if (server_fds[i] != -1)
- close(server_fds[i]);
+ if (server_fds[i] == -1)
+ break;
+ close(server_fds[i]);
}
bpf_link__destroy(lookup_link);
}
@@ -1053,11 +1057,14 @@ static void run_sk_assign(struct test_sk_lookup *skel,
struct bpf_program *lookup_prog,
const char *remote_ip, const char *local_ip)
{
- int server_fds[MAX_SERVERS] = { -1 };
+ int server_fds[MAX_SERVERS];
struct bpf_sk_lookup ctx;
__u64 server_cookie;
int i, err;
+ /* set all fds to -1 */
+ memset(server_fds, 0xFF, sizeof(server_fds));
+
DECLARE_LIBBPF_OPTS(bpf_test_run_opts, opts,
.ctx_in = &ctx,
.ctx_size_in = sizeof(ctx),
@@ -1097,8 +1104,9 @@ static void run_sk_assign(struct test_sk_lookup *skel,
close_servers:
for (i = 0; i < ARRAY_SIZE(server_fds); i++) {
- if (server_fds[i] != -1)
- close(server_fds[i]);
+ if (server_fds[i] == -1)
+ break;
+ close(server_fds[i]);
}
}
--
2.33.0
