From a47d4576cd1c58157a2d8cfffa93aa7ca375eede Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 28 Aug 2015 10:30:15 +0200 Subject: x86/irq: Do not dereference irq descriptor before checking it Having the IS_NULL_OR_ERR() check after dereferencing the pointer is not really working well. Move the dereference after the check. Fixes: a782a7e46bb5 'x86/irq: Store irq descriptor in vector array' Reported-and-tested-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/kernel/irq_32.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'arch/x86') diff --git a/arch/x86/kernel/irq_32.c b/arch/x86/kernel/irq_32.c index 217b01388038..c80cf6699678 100644 --- a/arch/x86/kernel/irq_32.c +++ b/arch/x86/kernel/irq_32.c @@ -150,7 +150,7 @@ void do_softirq_own_stack(void) bool handle_irq(struct irq_desc *desc, struct pt_regs *regs) { - unsigned int irq = irq_desc_get_irq(desc); + unsigned int irq; int overflow; overflow = check_stack_overflow(); @@ -158,6 +158,7 @@ bool handle_irq(struct irq_desc *desc, struct pt_regs *regs) if (IS_ERR_OR_NULL(desc)) return false; + irq = irq_desc_get_irq(desc); if (user_mode(regs) || !execute_on_irq_stack(overflow, desc, irq)) { if (unlikely(overflow)) print_stack_overflow(); -- cgit v1.2.3