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Commit 216fcd29 authored by Kenji Kaneshige's avatar Kenji Kaneshige Committed by Tony Luck
Browse files

[IA64] Fix possible race in destroy_and_reserve_irq() 



Currently, destroy_and_reserve_irq() sets irq_status[irq] UNUSED using
clear_irq_vector() and sets irq_status[irq] RSVD using reserve_irq().
But there is a race window because vector_lock is once released between
them. This patch fixes this race window.

Signed-off-by: default avatarKenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: default avatarTony Luck <tony.luck@intel.com>
parent c4c376f7

arch/ia64/kernel/irq_ia64.c

+6 −11
Original line number Original line Diff line number Diff line
@@ -101,15 +101,6 @@ int check_irq_used(int irq) 
	return -1;

	return -1;

}

}





static void reserve_irq(unsigned int irq)

{

	unsigned long flags;



	spin_lock_irqsave(&vector_lock, flags);

	irq_status[irq] = IRQ_RSVD;

	spin_unlock_irqrestore(&vector_lock, flags);

}



static inline int find_unassigned_irq(void)

static inline int find_unassigned_irq(void)

{

{

	int irq;

	int irq;
@@ -302,10 +293,14 @@ static cpumask_t vector_allocation_domain(int cpu) 




void destroy_and_reserve_irq(unsigned int irq)

void destroy_and_reserve_irq(unsigned int irq)

{

{

	unsigned long flags;



	dynamic_irq_cleanup(irq);

	dynamic_irq_cleanup(irq);





	clear_irq_vector(irq);

	spin_lock_irqsave(&vector_lock, flags);

	reserve_irq(irq);

	__clear_irq_vector(irq);

	irq_status[irq] = IRQ_RSVD;

	spin_unlock_irqrestore(&vector_lock, flags);

}

}





static int __reassign_irq_vector(int irq, int cpu)

static int __reassign_irq_vector(int irq, int cpu)