irq: fix cpumask memory leak on offstack cpumask kernels

Need to free the old cpumask for affinity and pending_mask.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
LKML-Reference: <49D18FF0.50707@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

include/linux/irq.h

@@ -482,6 +482,16 @@ static inline void init_copy_desc_masks(struct irq_desc *old_desc,
 #endif
 }
 
+static inline void free_desc_masks(struct irq_desc *old_desc,
+				   struct irq_desc *new_desc)
+{
+	free_cpumask_var(old_desc->affinity);
+
+#ifdef CONFIG_GENERIC_PENDING_IRQ
+	free_cpumask_var(old_desc->pending_mask);
+#endif
+}
+
 #else /* !CONFIG_SMP */
 
 static inline bool init_alloc_desc_masks(struct irq_desc *desc, int cpu,
@@ -495,6 +505,10 @@ static inline void init_copy_desc_masks(struct irq_desc *old_desc,
 {
 }
 
+static inline void free_desc_masks(struct irq_desc *old_desc,
+				   struct irq_desc *new_desc)
+{
+}
 #endif	/* CONFIG_SMP */
 
 #endif /* _LINUX_IRQ_H */

kernel/irq/numa_migrate.c

@@ -54,6 +54,7 @@ static bool init_copy_one_irq_desc(int irq, struct irq_desc *old_desc,
 static void free_one_irq_desc(struct irq_desc *old_desc, struct irq_desc *desc)
 {
 	free_kstat_irqs(old_desc, desc);
+	free_desc_masks(old_desc, desc);
 	arch_free_chip_data(old_desc, desc);
 }