On Thu, Oct 27, 2022 at 4:34 AM Rong Tao rtoax@foxmail.com wrote:
From: Rong Tao rongtao@cestc.cn
Compile samples/bpf, error: $ cd samples/bpf $ make ... In function ‘__enable_controllers’: samples/bpf/../../tools/testing/selftests/bpf/cgroup_helpers.c:80:17: warning: ‘strncpy’ specified bound 4097 equals destination size [-Wstringop-truncation] 80 | strncpy(enable, controllers, sizeof(enable)); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Signed-off-by: Rong Tao rongtao@cestc.cn
tools/testing/selftests/bpf/cgroup_helpers.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/bpf/cgroup_helpers.c b/tools/testing/selftests/bpf/cgroup_helpers.c index e914cc45b766..a70e873b267e 100644 --- a/tools/testing/selftests/bpf/cgroup_helpers.c +++ b/tools/testing/selftests/bpf/cgroup_helpers.c @@ -77,7 +77,7 @@ static int __enable_controllers(const char *cgroup_path, const char *controllers enable[len] = 0; close(fd); } else {
strncpy(enable, controllers, sizeof(enable));
strncpy(enable, controllers, sizeof(enable) - 1);
enable is not initialized, so we might end up with non-zero-terminated string. Let's enable[0] = '\0'; at the beginning and then strncat() here?
} snprintf(path, sizeof(path), "%s/cgroup.subtree_control", cgroup_path);-- 2.31.1