Commit 17549b0f authored Dec 16, 2022 by Manfred Spraul Committed by Thomas Gleixner Jan 11, 2023

genirq: Add might_sleep() to disable_irq()

With the introduction of threaded interrupt handlers, it is virtually
never safe to call disable_irq() from non-premptible context.

Thus: Update the documentation, add an explicit might_sleep() to catch any
offenders. This is more obvious and straight forward than the implicit
might_sleep() check deeper down in the disable_irq() call chain.

Fixes: 3aa551c9 ("genirq: add threaded interrupt handler support")
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20221216150441.200533-3-manfred@colorfullife.com

parent b7bfaa76

kernel/irq/manage.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -723,10 +723,13 @@ EXPORT_SYMBOL(disable_irq_nosync);
		* to complete before returning. If you use this function while
		* holding a resource the IRQ handler may need you will deadlock.
		*
		* This function may be called - with care - from IRQ context.
		* Can only be called from preemptible code as it might sleep when
		* an interrupt thread is associated to @irq.
		*
		*/
		void disable_irq(unsigned int irq)
		{
		might_sleep();
		if (!__disable_irq_nosync(irq))
		synchronize_irq(irq);
		}