Commit 4b01f5a4 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull smp fix from Thomas Gleixner:
 "Add warnings to the smp function calls so callers from wrong contexts
  get detected"

* 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  smp: Warn on function calls from softirq context
parents 70e6e1b9 19dbdcb8

kernel/smp.c

+16 −0
Original line number Diff line number Diff line
@@ -291,6 +291,14 @@ int smp_call_function_single(int cpu, smp_call_func_t func, void *info, 
	WARN_ON_ONCE(cpu_online(this_cpu) && irqs_disabled()

		     && !oops_in_progress);



	/*

	 * When @wait we can deadlock when we interrupt between llist_add() and

	 * arch_send_call_function_ipi*(); when !@wait we can deadlock due to

	 * csd_lock() on because the interrupt context uses the same csd

	 * storage.

	 */

	WARN_ON_ONCE(!in_task());



	csd = &csd_stack;

	if (!wait) {

		csd = this_cpu_ptr(&csd_data);
@@ -416,6 +424,14 @@ void smp_call_function_many(const struct cpumask *mask, 
	WARN_ON_ONCE(cpu_online(this_cpu) && irqs_disabled()

		     && !oops_in_progress && !early_boot_irqs_disabled);



	/*

	 * When @wait we can deadlock when we interrupt between llist_add() and

	 * arch_send_call_function_ipi*(); when !@wait we can deadlock due to

	 * csd_lock() on because the interrupt context uses the same csd

	 * storage.

	 */

	WARN_ON_ONCE(!in_task());



	/* Try to fastpath.  So, what's a CPU they want? Ignoring this one. */

	cpu = cpumask_first_and(mask, cpu_online_mask);

	if (cpu == this_cpu)

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