[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>
diff --git a/arch/ia64/kernel/irq_ia64.c b/arch/ia64/kernel/irq_ia64.c
index 9386b95..c47c8ac 100644
--- a/arch/ia64/kernel/irq_ia64.c
+++ b/arch/ia64/kernel/irq_ia64.c
@@ -101,15 +101,6 @@
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 @@
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)