1 files changed, 22 insertions, 6 deletions

diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index 470d08c82bbe..bdb180325551 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -54,14 +54,18 @@ static void warn_no_thread(unsigned int irq, struct irqaction *action)
 static void irq_wake_thread(struct irq_desc *desc, struct irqaction *action)
 {
         /*
-         * Wake up the handler thread for this action. In case the
-         * thread crashed and was killed we just pretend that we
-         * handled the interrupt. The hardirq handler has disabled the
-         * device interrupt, so no irq storm is lurking. If the
+         * In case the thread crashed and was killed we just pretend that
+         * we handled the interrupt. The hardirq handler has disabled the
+         * device interrupt, so no irq storm is lurking.
+         */
+        if (action->thread->flags & PF_EXITING)
+                return;
+
+        /*
+         * Wake up the handler thread for this action. If the
          * RUNTHREAD bit is already set, nothing to do.
          */
-        if (test_bit(IRQTF_DIED, &action->thread_flags) ||
-            test_and_set_bit(IRQTF_RUNTHREAD, &action->thread_flags))
+        if (test_and_set_bit(IRQTF_RUNTHREAD, &action->thread_flags))
                 return;
 
         /*
@@ -110,6 +114,18 @@ static void irq_wake_thread(struct irq_desc *desc, struct irqaction *action)
          * threads_oneshot untouched and runs the thread another time.
          */
         desc->threads_oneshot |= action->thread_mask;
+
+        /*
+         * We increment the threads_active counter in case we wake up
+         * the irq thread. The irq thread decrements the counter when
+         * it returns from the handler or in the exit path and wakes
+         * up waiters which are stuck in synchronize_irq() when the
+         * active count becomes zero. synchronize_irq() is serialized
+         * against this code (hard irq handler) via IRQS_INPROGRESS
+         * like the finalize_oneshot() code. See comment above.
+         */
+        atomic_inc(&desc->threads_active);
+
         wake_up_process(action->thread);
 }