irq: allow free_irq() after setup_irq()

PATCH In review Magnus Damm 1 participant 1 message Dec 1, 2008

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Magnus Damm

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2008-12-01 10:33 UTC #0 lore raw

PATCH 5/10 irq: allow free_irq() after setup_irq()

From: Magnus Damm <[email protected]>

This patch adds support for using free_irq() on interrupts allocated with setup_irq(). Without this patch the kernel will try to kfree() the struct irqaction passed as argument to setup_irq().

Signed-off-by Magnus Damm <[email protected]>

---

 include/linux/interrupt.h |    2 ++
 kernel/irq/manage.c       |    4 +++-
 2 files changed, 5 insertions(+), 1 deletion(-)

include/linux/interrupt.h +2 -0

@@ -48,6 +48,7 @@
  * IRQF_IRQPOLL - Interrupt is used for polling (only the interrupt that is
  *                registered first in an shared interrupt is considered for
  *                performance reasons)
+ * IRQF_STATIC - Interrupt requested with setup_irq(), do not kfree().
  */
 #define IRQF_DISABLED		0x00000020
 #define IRQF_SAMPLE_RANDOM	0x00000040

@@ -57,6 +58,7 @@
 #define IRQF_PERCPU		0x00000400
 #define IRQF_NOBALANCING	0x00000800
 #define IRQF_IRQPOLL		0x00001000
+#define IRQF_STATIC		0x00002000
 
 typedef irqreturn_t (*irq_handler_t)(int, void *);

kernel/irq/manage.c +3 -1

@@ -509,6 +509,7 @@ int setup_irq(unsigned int irq, struct i
 {
 	struct irq_desc *desc = irq_to_desc(irq);
 
+	act->flags |= IRQF_STATIC;
 	return __setup_irq(irq, desc, act);
 }

@@ -585,7 +586,8 @@ void free_irq(unsigned int irq, void *de
 				local_irq_restore(flags);
 			}
 #endif
-			kfree(action);
+			if (!(action->flags & IRQF_STATIC))
+				kfree(action);
 			return;
 		}
 		printk(KERN_ERR "Trying to free already-free IRQ %d\n", irq);