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

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 9ec34a2..1401afa 100644 (file)
--- 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);