IRQ_NOPROBE helper functions (46f4f8f6) · Commits · 戴 / test

Probing non-ISA interrupts using the handle_percpu_irq as their handle_irq method may crash the system because handle_percpu_irq does not check IRQ_WAITING. This for example hits the MIPS Qemu configuration. This patch provides two helper functions set_irq_noprobe and set_irq_probe to set rsp. clear the IRQ_NOPROBE flag. The only current caller is MIPS code but this really belongs into generic code. As an aside, interrupt probing these days has become a mostly obsolete if not dangerous art. I think Linux interrupts should be changed to default to non-probing but that's subject of this patch. Signed-off-by:

Ralf Baechle <ralf@linux-mips.org> Acked-and-tested-by:

Rob Landley <rob@landley.net> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

include/linux/irq.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -367,6 +367,9 @@ set_irq_chained_handler(unsigned int irq,
		__set_irq_handler(irq, handle, 1, NULL);
		}

		extern void set_irq_noprobe(unsigned int irq);
		extern void set_irq_probe(unsigned int irq);

		/* Handle dynamic irq creation and destruction */
		extern int create_irq(void);
		extern void destroy_irq(unsigned int irq);

kernel/irq/chip.c

+36 −0

Original line number	Diff line number	Diff line
		@@ -589,3 +589,39 @@ set_irq_chip_and_handler_name(unsigned int irq, struct irq_chip *chip,
		set_irq_chip(irq, chip);
		__set_irq_handler(irq, handle, 0, name);
		}

		void __init set_irq_noprobe(unsigned int irq)
		{
		struct irq_desc *desc;
		unsigned long flags;

		if (irq >= NR_IRQS) {
		printk(KERN_ERR "Trying to mark IRQ%d non-probeable\n", irq);

		return;
		}

		desc = irq_desc + irq;

		spin_lock_irqsave(&desc->lock, flags);
		desc->status \|= IRQ_NOPROBE;
		spin_unlock_irqrestore(&desc->lock, flags);
		}

		void __init set_irq_probe(unsigned int irq)
		{
		struct irq_desc *desc;
		unsigned long flags;

		if (irq >= NR_IRQS) {
		printk(KERN_ERR "Trying to mark IRQ%d probeable\n", irq);

		return;
		}

		desc = irq_desc + irq;

		spin_lock_irqsave(&desc->lock, flags);
		desc->status &= ~IRQ_NOPROBE;
		spin_unlock_irqrestore(&desc->lock, flags);
		}

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