[S390] show_interrupts: prevent cpu hotplug when walking cpu_online_map.

Surround all the code withing show_interrupts() with
get/put_online_cpus() to prevent strange results wrt cpu hotplug.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/arch/s390/kernel/irq.c b/arch/s390/kernel/irq.c
index c59a86dca584..e7c5bfb7c755 100644
--- a/arch/s390/kernel/irq.c
+++ b/arch/s390/kernel/irq.c
@@ -25,6 +25,7 @@ int show_interrupts(struct seq_file *p, void *v)
         static const char *intrclass_names[] = { "EXT", "I/O", };
         int i = *(loff_t *) v, j;
 
+        get_online_cpus();
         if (i == 0) {
                 seq_puts(p, "           ");
                 for_each_online_cpu(j)
@@ -43,7 +44,7 @@ int show_interrupts(struct seq_file *p, void *v)
                 seq_putc(p, '\n');
 
         }
-
+        put_online_cpus();
         return 0;
 }