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[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: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
This commit is contained in:
Kenji Kaneshige 2007-07-30 11:56:30 +09:00 committed by Tony Luck
parent c4c376f7e1
commit 216fcd29af
1 changed files with 6 additions and 11 deletions
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17
arch/ia64/kernel/irq_ia64.c
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@ -101,15 +101,6 @@ int check_irq_used(int irq)
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)
{
int irq;
@ -302,10 +293,14 @@ static cpumask_t vector_allocation_domain(int cpu)
void destroy_and_reserve_irq(unsigned int irq)
{
unsigned long flags;
dynamic_irq_cleanup(irq);
clear_irq_vector(irq);
reserve_irq(irq);
spin_lock_irqsave(&vector_lock, flags);
__clear_irq_vector(irq);
irq_status[irq] = IRQ_RSVD;
spin_unlock_irqrestore(&vector_lock, flags);
}
static int __reassign_irq_vector(int irq, int cpu)