From c3b4df92450f734f39449b31a415043141bb151f Mon Sep 17 00:00:00 2001
From: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Date: Tue, 26 Jul 2011 16:08:45 -0700
Subject: [PATCH] --- yaml --- r: 260422 b: refs/heads/master c:
 a64a26e822ddb739de464540dfd2cbb6abce47d5 h: refs/heads/master v: v3

---
 [refs]                        |  2 +-
 trunk/include/linux/cpumask.h | 14 ++++++++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index 88cf4d7e57a2..bae1327e9923 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 37e7b5f1535dddaace865b25df34a2d049a3a66f
+refs/heads/master: a64a26e822ddb739de464540dfd2cbb6abce47d5
diff --git a/trunk/include/linux/cpumask.h b/trunk/include/linux/cpumask.h
index b24ac56477b4..4f7a63237471 100644
--- a/trunk/include/linux/cpumask.h
+++ b/trunk/include/linux/cpumask.h
@@ -617,6 +617,20 @@ static inline size_t cpumask_size(void)
  *	  ... use 'tmpmask' like a normal struct cpumask * ...
  *
  *	free_cpumask_var(tmpmask);
+ *
+ *
+ * However, one notable exception is there. alloc_cpumask_var() allocates
+ * only nr_cpumask_bits bits (in the other hand, real cpumask_t always has
+ * NR_CPUS bits). Therefore you don't have to dereference cpumask_var_t.
+ *
+ *	cpumask_var_t tmpmask;
+ *	if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL))
+ *		return -ENOMEM;
+ *
+ *	var = *tmpmask;
+ *
+ * This code makes NR_CPUS length memcopy and brings to a memory corruption.
+ * cpumask_copy() provide safe copy functionality.
  */
 #ifdef CONFIG_CPUMASK_OFFSTACK
 typedef struct cpumask *cpumask_var_t;