genirq: Wake up irq thread after action has been installed (69ab8494) · Commits · 戴 / test

The wake_up_process() of the new irq thread in __setup_irq() is too early as the irqaction is not yet fully initialized especially action->irq is not yet set. The interrupt thread might dereference the wrong irq descriptor. Move the wakeup after the action is installed and action->irq has been set. Reported-by:

Michael Buesch <mb@bu3sch.de> Signed-off-by:

Thomas Gleixner <tglx@linutronix.de> Tested-by:

Michael Buesch <mb@bu3sch.de>

kernel/irq/manage.c

+8 −2

Original line number	Diff line number	Diff line
		@@ -607,7 +607,6 @@ __setup_irq(unsigned int irq, struct irq_desc desc, struct irqaction new)
		*/
		get_task_struct(t);
		new->thread = t;
		wake_up_process(t);
		}

		/*
		@@ -690,6 +689,7 @@ __setup_irq(unsigned int irq, struct irq_desc desc, struct irqaction new)
		(int)(new->flags & IRQF_TRIGGER_MASK));
		}

		new->irq = irq;
		*old_ptr = new;

		/* Reset broken irq detection when installing new handler */
		@@ -707,7 +707,13 @@ __setup_irq(unsigned int irq, struct irq_desc desc, struct irqaction new)

		spin_unlock_irqrestore(&desc->lock, flags);

		new->irq = irq;
		/*
		* Strictly no need to wake it up, but hung_task complains
		* when no hard interrupt wakes the thread up.
		*/
		if (new->thread)
		wake_up_process(new->thread);

		register_irq_proc(irq, desc);
		new->dir = NULL;
		register_handler_proc(irq, new);

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