From: Kenji Kaneshige Date: Mon, 30 Jul 2007 02:56:30 +0000 (+0900) Subject: [IA64] Fix possible race in destroy_and_reserve_irq() X-Git-Tag: v2.6.23-rc2~22^2~3 X-Git-Url: http://www.pilppa.org/gitweb/gitweb.cgi?a=commitdiff_plain;h=216fcd29af47ab53ffd87e82139fcc4095e34d91;p=linux-2.6-omap-h63xx.git [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 Signed-off-by: Tony Luck --- diff --git a/arch/ia64/kernel/irq_ia64.c b/arch/ia64/kernel/irq_ia64.c index 9386b955eed..c47c8acc96e 100644 --- a/arch/ia64/kernel/irq_ia64.c +++ b/arch/ia64/kernel/irq_ia64.c @@ -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)