powerpc: Make virq_debug_show() cope with sparse irq_descs

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 4 insertions, 1 deletions

diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 65632215f020..baa49eb93228 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -1065,8 +1065,11 @@ static int virq_debug_show(struct seq_file *m, void *private)
         seq_printf(m, "%-5s  %-7s  %-15s  %s\n", "virq", "hwirq",
                       "chip name", "host name");
 
-        for (i = 1; i < NR_IRQS; i++) {
+        for (i = 1; i < nr_irqs; i++) {
                 desc = irq_to_desc(i);
+                if (!desc)
+                        continue;
+
                 spin_lock_irqsave(&desc->lock, flags);
 
                 if (desc->action && desc->action->handler) {