From d3b0b80064e0416850f818184b8f7bba9fdf8c40 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Fri, 11 Feb 2022 11:09:27 -0800 Subject: [PATCH] selftests/bpf: Fix GCC11 compiler warnings in -O2 mode When compiling selftests in -O2 mode with GCC1, we get three new compilations warnings about potentially uninitialized variables. Compiler is wrong 2 out of 3 times, but this patch makes GCC11 happy anyways, as it doesn't cost us anything and makes optimized selftests build less annoying. The amazing one is tc_redirect case of token that is malloc()'ed before ASSERT_OK_PTR() check is done on it. Seems like GCC pessimistically assumes that libbpf_get_error() will dereference the contents of the pointer (no it won't), so the only way I found to shut GCC up was to do zero-initializaing calloc(). This one was new to me. For linfo case, GCC didn't realize that linfo_size will be initialized by the function that is returning linfo_size as out parameter. core_reloc.c case was a real bug, we can goto cleanup before initializing obj. But we don't need to do any clean up, so just continue iteration intstead. Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20220211190927.1434329-1-andrii@kernel.org --- tools/testing/selftests/bpf/prog_tests/btf.c | 2 +- tools/testing/selftests/bpf/prog_tests/core_reloc.c | 2 +- tools/testing/selftests/bpf/prog_tests/tc_redirect.c | 2 +- 3 files changed, 3 insertions(+), 3 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/btf.c b/tools/testing/selftests/bpf/prog_tests/btf.c index 8b652f5ce423..ec823561b912 100644 --- a/tools/testing/selftests/bpf/prog_tests/btf.c +++ b/tools/testing/selftests/bpf/prog_tests/btf.c @@ -6556,7 +6556,7 @@ static int test_get_linfo(const struct prog_info_raw_test *test, static void do_test_info_raw(unsigned int test_num) { const struct prog_info_raw_test *test = &info_raw_tests[test_num - 1]; - unsigned int raw_btf_size, linfo_str_off, linfo_size; + unsigned int raw_btf_size, linfo_str_off, linfo_size = 0; int btf_fd = -1, prog_fd = -1, err = 0; void *raw_btf, *patched_linfo = NULL; const char *ret_next_str; diff --git a/tools/testing/selftests/bpf/prog_tests/core_reloc.c b/tools/testing/selftests/bpf/prog_tests/core_reloc.c index b8bdd1c3efca..68e4c8dafa00 100644 --- a/tools/testing/selftests/bpf/prog_tests/core_reloc.c +++ b/tools/testing/selftests/bpf/prog_tests/core_reloc.c @@ -872,7 +872,7 @@ void test_core_reloc(void) if (test_case->btf_src_file) { err = access(test_case->btf_src_file, R_OK); if (!ASSERT_OK(err, "btf_src_file")) - goto cleanup; + continue; } open_opts.btf_custom_path = test_case->btf_src_file; diff --git a/tools/testing/selftests/bpf/prog_tests/tc_redirect.c b/tools/testing/selftests/bpf/prog_tests/tc_redirect.c index c2426df58e17..647b0a833628 100644 --- a/tools/testing/selftests/bpf/prog_tests/tc_redirect.c +++ b/tools/testing/selftests/bpf/prog_tests/tc_redirect.c @@ -140,7 +140,7 @@ static struct nstoken *open_netns(const char *name) int err; struct nstoken *token; - token = malloc(sizeof(struct nstoken)); + token = calloc(1, sizeof(struct nstoken)); if (!ASSERT_OK_PTR(token, "malloc token")) return NULL;