cpumask: fix bug in use cpumask_var_t in irq_desc
Impact: fix bug where new irq_desc uses old cpumask pointers which are freed.
As Yinghai pointed out, init_copy_one_irq_desc() copies the old desc to
the new desc overwriting the cpumask pointers. Since the old_desc and
the cpumask pointers are freed, then memory corruption will occur if
these old pointers are used.
Move the allocation of these pointers to after the copy.
Signed-off-by: Mike Travis <travis@sgi.com>
Cc: Yinghai Lu <yinghai@kernel.org>
diff --git a/include/linux/irq.h b/include/linux/irq.h
index fa27210..27a6753 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -426,15 +426,18 @@
/**
* init_alloc_desc_masks - allocate cpumasks for irq_desc
* @desc: pointer to irq_desc struct
+ * @cpu: cpu which will be handling the cpumasks
* @boot: true if need bootmem
*
* Allocates affinity and pending_mask cpumask if required.
* Returns true if successful (or not required).
* Side effect: affinity has all bits set, pending_mask has all bits clear.
*/
-static inline bool init_alloc_desc_masks(struct irq_desc *desc, int node,
+static inline bool init_alloc_desc_masks(struct irq_desc *desc, int cpu,
bool boot)
{
+ int node;
+
if (boot) {
alloc_bootmem_cpumask_var(&desc->affinity);
cpumask_setall(desc->affinity);
@@ -446,6 +449,8 @@
return true;
}
+ node = cpu_to_node(cpu);
+
if (!alloc_cpumask_var_node(&desc->affinity, GFP_ATOMIC, node))
return false;
cpumask_setall(desc->affinity);
@@ -484,7 +489,7 @@
#else /* !CONFIG_SMP */
-static inline bool init_alloc_desc_masks(struct irq_desc *desc, int node,
+static inline bool init_alloc_desc_masks(struct irq_desc *desc, int cpu,
bool boot)
{
return true;