Merge tag 'v3.12-rc4' into sched/core

Merge Linux v3.12-rc4 to fix a conflict and also to refresh the tree
before applying more scheduler patches.

Conflicts:
	arch/avr32/include/asm/Kbuild

Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 12 insertions, 3 deletions

diff --git a/kernel/softirq.c b/kernel/softirq.c
index 3e88612fc87e..dcab1d3fb53d 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -328,10 +328,19 @@ void irq_enter(void)
 
 static inline void invoke_softirq(void)
 {
-        if (!force_irqthreads)
-                __do_softirq();
-        else
+        if (!force_irqthreads) {
+                /*
+                 * We can safely execute softirq on the current stack if
+                 * it is the irq stack, because it should be near empty
+                 * at this stage. But we have no way to know if the arch
+                 * calls irq_exit() on the irq stack. So call softirq
+                 * in its own stack to prevent from any overrun on top
+                 * of a potentially deep task stack.
+                 */
+                do_softirq();
+        } else {
                 wakeup_softirqd();
+        }
 }
 
 static inline void tick_irq_exit(void)