kernel: enforce usage of CONFIG_TEST_USERSPACE

If a test tries to create a user thread, and the platform
suppors user mode, and CONFIG_TEST_USERSPACE has not been
enabled, fail an assertion.

Signed-off-by: Andrew Boie <[email protected]>

Author: Andrew Boie

kernel/thread.c

@@ -433,6 +433,12 @@ k_tid_t z_impl_k_thread_create(struct k_thread *new_thread,
 {
 	__ASSERT(!z_is_in_isr(), "Threads may not be created in ISRs");
 
+	/* Special case, only for unit tests */
+#if defined(CONFIG_TEST) && defined(CONFIG_ARCH_HAS_USERSPACE) && !defined(CONFIG_USERSPACE)
+	__ASSERT((options & K_USER) == 0,
+		 "Platform is capable of user mode, and test thread created with K_USER option, but CONFIG_TEST_USERSPACE or CONFIG_USERSPACE is not set\n");
+#endif
+
 	z_setup_new_thread(new_thread, stack, stack_size, entry, p1, p2, p3,
 			  prio, options, NULL);