Merge tag 'smp-urgent-2020-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull smp fix from Thomas Gleixner:
 "A single fix for stop machine.

  Mark functions no trace to prevent a crash caused by recursion when
  enabling or disabling a tracer on RISC-V (probably all architectures
  which patch through stop machine)"

* tag 'smp-urgent-2020-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  stop_machine, rcu: Mark functions as notrace

kernel/rcu/tree.c

@@ -409,7 +409,7 @@ bool rcu_eqs_special_set(int cpu)
  *
  * The caller must have disabled interrupts and must not be idle.
  */
-void rcu_momentary_dyntick_idle(void)
+notrace void rcu_momentary_dyntick_idle(void)
 {
 	int special;
 

kernel/stop_machine.c

@@ -178,7 +178,7 @@ static void ack_state(struct multi_stop_data *msdata)
 		set_state(msdata, msdata->state + 1);
 }
 
-void __weak stop_machine_yield(const struct cpumask *cpumask)
+notrace void __weak stop_machine_yield(const struct cpumask *cpumask)
 {
 	cpu_relax();
 }