From: Andrii Nakryiko andrii@kernel.org
mainline inclusion from mainline-5.18-rc1 commit d3b0b80064e0416850f818184b8f7bba9fdf8c40 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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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 andrii@kernel.org Signed-off-by: Alexei Starovoitov ast@kernel.org Link: https://lore.kernel.org/bpf/20220211190927.1434329-1-andrii@kernel.org (cherry picked from commit d3b0b80064e0416850f818184b8f7bba9fdf8c40) Signed-off-by: Wang Yufen wangyufen@huawei.com
Conflicts: tools/testing/selftests/bpf/prog_tests/core_reloc.c tools/testing/selftests/bpf/prog_tests/tc_redirect.c
Signed-off-by: Wang Yufen wangyufen@huawei.com --- tools/testing/selftests/bpf/prog_tests/btf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/bpf/prog_tests/btf.c b/tools/testing/selftests/bpf/prog_tests/btf.c index 73f42698c193..9c70f577e6a3 100644 --- a/tools/testing/selftests/bpf/prog_tests/btf.c +++ b/tools/testing/selftests/bpf/prog_tests/btf.c @@ -6111,7 +6111,7 @@ 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;