selftests/clone3: skip if clone3() is ENOSYS

If the clone3() syscall is not implemented we should skip the tests.

Fixes: 41585bbeee ("selftests: add tests for clone3() with *set_tid")
Fixes: 17a810699c ("selftests: add tests for clone3()")
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

tools/testing/selftests/clone3/clone3.c

@@ -131,6 +131,7 @@ int main(int argc, char *argv[])
 
 	uid_t uid = getuid();
 
+	test_clone3_supported();
 	ksft_print_header();
 	ksft_set_plan(17);
 

tools/testing/selftests/clone3/clone3_clear_sighand.c

@@ -20,32 +20,6 @@
 #define CLONE_CLEAR_SIGHAND 0x100000000ULL
 #endif
 
-static void test_clone3_supported(void)
-{
-	pid_t pid;
-	struct clone_args args = {};
-
-	if (__NR_clone3 < 0)
-		ksft_exit_skip("clone3() syscall is not supported\n");
-
-	/* Set to something that will always cause EINVAL. */
-	args.exit_signal = -1;
-	pid = sys_clone3(&args, sizeof(args));
-	if (!pid)
-		exit(EXIT_SUCCESS);
-
-	if (pid > 0) {
-		wait(NULL);
-		ksft_exit_fail_msg(
-			"Managed to create child process with invalid exit_signal\n");
-	}
-
-	if (errno == ENOSYS)
-		ksft_exit_skip("clone3() syscall is not supported\n");
-
-	ksft_print_msg("clone3() syscall supported\n");
-}
-
 static void nop_handler(int signo)
 {
 }
@@ -145,9 +119,10 @@ static void test_clone3_clear_sighand(void)
 int main(int argc, char **argv)
 {
 	ksft_print_header();
+	test_clone3_supported();
+
 	ksft_set_plan(1);
 
-	test_clone3_supported();
 	test_clone3_clear_sighand();
 
 	return ksft_exit_pass();

tools/testing/selftests/clone3/clone3_selftests.h

@@ -34,4 +34,30 @@ static pid_t sys_clone3(struct clone_args *args, size_t size)
 	return syscall(__NR_clone3, args, size);
 }
 
+static inline void test_clone3_supported(void)
+{
+	pid_t pid;
+	struct clone_args args = {};
+
+	if (__NR_clone3 < 0)
+		ksft_exit_skip("clone3() syscall is not supported\n");
+
+	/* Set to something that will always cause EINVAL. */
+	args.exit_signal = -1;
+	pid = sys_clone3(&args, sizeof(args));
+	if (!pid)
+		exit(EXIT_SUCCESS);
+
+	if (pid > 0) {
+		wait(NULL);
+		ksft_exit_fail_msg(
+			"Managed to create child process with invalid exit_signal\n");
+	}
+
+	if (errno == ENOSYS)
+		ksft_exit_skip("clone3() syscall is not supported\n");
+
+	ksft_print_msg("clone3() syscall supported\n");
+}
+
 #endif /* _CLONE3_SELFTESTS_H */

tools/testing/selftests/clone3/clone3_set_tid.c

@@ -156,12 +156,13 @@ int main(int argc, char *argv[])
 	pid_t pid, ns1, ns2, ns3, ns_pid;
 	pid_t set_tid[MAX_PID_NS_LEVEL * 2];
 
+	ksft_print_header();
+	test_clone3_supported();
+	ksft_set_plan(29);
+
 	if (pipe(pipe_1) < 0 || pipe(pipe_2) < 0)
 		ksft_exit_fail_msg("pipe() failed\n");
 
-	ksft_print_header();
-	ksft_set_plan(29);
-
 	f = fopen("/proc/sys/kernel/pid_max", "r");
 	if (f == NULL)
 		ksft_exit_fail_msg(