kernel: When TLS, skip switched_out tracing hook from dummy thread

The dummy thread doesn't include a TLS area, so any thread local variables
will fail to work if used in the switched_out tracing hook. Skip the hook
in this case, as it's not really accurate anyways; the dummy thread is
only used to set context for the initial switch for each core.

Signed-off-by: Keith Packard <[email protected]>

Author: keith-packard

kernel/thread.c

@@ -1058,6 +1058,12 @@ void z_thread_mark_switched_out(void)
 #endif
 
 #ifdef CONFIG_TRACING
+#ifdef CONFIG_THREAD_LOCAL_STORAGE
+	/* Dummy thread won't have TLS set up to run arbitrary code */
+	if (!_current_cpu->current ||
+	    (_current_cpu->current->base.thread_state & _THREAD_DUMMY) != 0)
+		return;
+#endif
 	SYS_PORT_TRACING_FUNC(k_thread, switched_out);
 #endif
 }