[PATCH bpf-next v1 5/6] bpf: selftests: Fix fd cleanup in sk_lookup test
From: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Date: 2021-10-06 00:29:15
Also in:
bpf
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [selftests] (test runners & infrastructure), kernel selftest framework, the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Shuah Khan, Linus Torvalds
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@cloudflare.com>
Fixes: 0ab5539f8584 (selftests/bpf: Tests for BPF_SK_LOOKUP attach point)
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
---
.../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