free_irq(): fix DEBUG_SHIRQ handling

If we're going to run the handler from free_irq() then we must do it with
local irq's disabled.  Otherwise lockdep complains that the handler is taking
irq-safe spinlocks in a non-irq-safe fashion.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 203a518b6f14..853aefbd184b 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -462,7 +462,9 @@ void free_irq(unsigned int irq, void *dev_id)
                  * We do this after actually deregistering it, to make sure that
                  * a 'real' IRQ doesn't run in parallel with our fake
                  */
+                local_irq_save(flags);
                 handler(irq, dev_id);
+                local_irq_restore(flags);
         }
 #endif
 }