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authorThomas Gleixner <tglx@linutronix.de>2009-08-17 14:07:16 +0200
committerThomas Gleixner <tglx@linutronix.de>2009-08-18 17:22:43 +0200
commit69ab849439b506cd8dd2879527fdb64d95dd5211 (patch)
tree059fba8bcb8147fafcd4e86db61f0f88d6a84095 /kernel
parent2d860ad76f4ee4d2eba0fe3797c8d7cdce432cc0 (diff)
downloadlinux-69ab849439b506cd8dd2879527fdb64d95dd5211.tar.gz
genirq: Wake up irq thread after action has been installed
The wake_up_process() of the new irq thread in __setup_irq() is too
early as the irqaction is not yet fully initialized especially
action->irq is not yet set. The interrupt thread might dereference the
wrong irq descriptor.

Move the wakeup after the action is installed and action->irq has been
set.

Reported-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Buesch <mb@bu3sch.de>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/irq/manage.c10
1 files changed, 8 insertions, 2 deletions
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index d222515a5a06..0ec9ed831737 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -607,7 +607,6 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
 		 */
 		get_task_struct(t);
 		new->thread = t;
-		wake_up_process(t);
 	}
 
 	/*
@@ -690,6 +689,7 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
 				(int)(new->flags & IRQF_TRIGGER_MASK));
 	}
 
+	new->irq = irq;
 	*old_ptr = new;
 
 	/* Reset broken irq detection when installing new handler */
@@ -707,7 +707,13 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
 
 	spin_unlock_irqrestore(&desc->lock, flags);
 
-	new->irq = irq;
+	/*
+	 * Strictly no need to wake it up, but hung_task complains
+	 * when no hard interrupt wakes the thread up.
+	 */
+	if (new->thread)
+		wake_up_process(new->thread);
+
 	register_irq_proc(irq, desc);
 	new->dir = NULL;
 	register_handler_proc(irq, new);