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>

diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 20e47e045395ccd5bb74cd7b8c8a02047fc5f967..8ae808d110f445f352ca686faf3a29d9d93bfa50 100644 (file)
--- 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);