selftests/bpf: Fix a compiler warning in local_storage test

Some compilers trigger a warning when tmp_dir_path is allocated
with a fixed size of 64-bytes and used in the following snprintf:

  snprintf(tmp_exec_path, sizeof(tmp_exec_path), "%s/copy_of_rm",
	   tmp_dir_path);

  warning: ‘/copy_of_rm’ directive output may be truncated writing 11
  bytes into a region of size between 1 and 64 [-Wformat-truncation=]

This is because it assumes that tmp_dir_path can be a maximum of 64
bytes long and, therefore, the end-result can get truncated. Fix it by
not using a fixed size in the initialization of tmp_dir_path which
allows the compiler to track actual size of the array better.

Fixes: 2f94ac1918 ("bpf: Update local storage test to check handling of null ptrs")
Signed-off-by: KP Singh <kpsingh@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210202213730.1906931-1-kpsingh@kernel.org
This commit is contained in:
KP Singh 2021-02-02 21:37:30 +00:00 committed by Andrii Nakryiko
parent 37086bfdc7
commit 15075bb722

View file

@ -113,7 +113,7 @@ static bool check_syscall_operations(int map_fd, int obj_fd)
void test_test_local_storage(void)
{
char tmp_dir_path[64] = "/tmp/local_storageXXXXXX";
char tmp_dir_path[] = "/tmp/local_storageXXXXXX";
int err, serv_sk = -1, task_fd = -1, rm_fd = -1;
struct local_storage *skel = NULL;
char tmp_exec_path[64];