From 9717967c4b704ce344c954afb5bb160aa9c01c34 Mon Sep 17 00:00:00 2001 From: Yinghai Lu <yinghai@kernel.org> Date: Mon, 18 Oct 2010 13:47:48 -0700 Subject: [PATCH] x86: ioapic: Call free_irte only if interrupt remapping enabled On a system that support intr-rempping when booting with "intremap=off" [ 177.895501] BUG: unable to handle kernel NULL pointer dereference at 00000000000000f8 [ 177.913316] IP: [<ffffffff8145fc18>] free_irte+0x47/0xc0 ... [ 178.173326] Call Trace: [ 178.173574] [<ffffffff810515b4>] destroy_irq+0x3a/0x75 [ 178.192934] [<ffffffff81051834>] arch_teardown_msi_irq+0xe/0x10 [ 178.193418] [<ffffffff81458dc3>] arch_teardown_msi_irqs+0x56/0x7f [ 178.213021] [<ffffffff81458e79>] free_msi_irqs+0x8d/0xeb Call free_irte only when interrupt remapping is enabled. Signed-off-by: Yinghai Lu <yinghai@kernel.org> LKML-Reference: <4CBCB274.7010108@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> --- arch/x86/kernel/apic/io_apic.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c index 20e47e045395..8ae808d110f4 100644 --- a/arch/x86/kernel/apic/io_apic.c +++ b/arch/x86/kernel/apic/io_apic.c @@ -3109,7 +3109,8 @@ void destroy_irq(unsigned int irq) irq_set_status_flags(irq, IRQ_NOREQUEST|IRQ_NOPROBE); - free_irte(irq); + if (intr_remapping_enabled) + free_irte(irq); raw_spin_lock_irqsave(&vector_lock, flags); __clear_irq_vector(irq, cfg); raw_spin_unlock_irqrestore(&vector_lock, flags);