x86: Fix NULL pointer access in irq_force_complete_move() for Xen guests
Upstream PV guests fail to boot because of a NULL pointer in
irq_force_complete_move(). It is possible that xen guests have
irq_desc->chip_data = NULL.
Test for NULL chip_data pointer before attempting to complete an irq move.
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
LKML-Reference: <20100427152434.16193.49104.sendpatchset@prarit.bos.redhat.com>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: <stable@kernel.org> [2.6.33]
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 127b871..eb2789c 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -2545,6 +2545,9 @@
struct irq_desc *desc = irq_to_desc(irq);
struct irq_cfg *cfg = desc->chip_data;
+ if (!cfg)
+ return;
+
__irq_complete_move(&desc, cfg->vector);
}
#else