genirq: Mark expected switch case fall-through

In preparation to enabling -Wimplicit-fallthrough, mark switch
cases where we are expecting to fall through.

With -Wimplicit-fallthrough added to CFLAGS:

 kernel/irq/manage.c: In function ‘irq_do_set_affinity’:
 kernel/irq/manage.c:198:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
   cpumask_copy(desc->irq_common_data.affinity, mask);
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 kernel/irq/manage.c:199:2: note: here
   case IRQ_SET_MASK_OK_NOCOPY:
   ^~~~

Annotate it.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20190228213714.GA9246@embeddedor

1 files changed, 1 insertions, 0 deletions

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 9ec34a2a6638..1401afa0d58a 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -196,6 +196,7 @@ int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
         case IRQ_SET_MASK_OK:
         case IRQ_SET_MASK_OK_DONE:
                 cpumask_copy(desc->irq_common_data.affinity, mask);
+                /* fall through */
         case IRQ_SET_MASK_OK_NOCOPY:
                 irq_validate_effective_affinity(data);
                 irq_set_thread_affinity(desc);