From: Jason Xing <kernelxing@xxxxxxxxxxx> The output goes like this if I make samples/bpf: ...warning: no previous prototype for ‘get_cgroup_id_from_path’... Make this function static could solve the warning problem since no one outside of the file calls it. Signed-off-by: Jason Xing <kernelxing@xxxxxxxxxxx> --- 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 19be9c63d5e8..f2952a65dcc2 100644 --- a/tools/testing/selftests/bpf/cgroup_helpers.c +++ b/tools/testing/selftests/bpf/cgroup_helpers.c @@ -429,7 +429,7 @@ int create_and_get_cgroup(const char *relative_path) * which is an invalid cgroup id. * If there is a failure, it prints the error to stderr. */ -unsigned long long get_cgroup_id_from_path(const char *cgroup_workdir) +static unsigned long long get_cgroup_id_from_path(const char *cgroup_workdir) { int dirfd, err, flags, mount_id, fhsize; union { -- 2.37.3