[tip:x86/pat] x86, pat: In rbt_memtype_check_insert(), update new->type only if valid

["tip-bot for Pallipadi, Venkatesh" <venkatesh.pallipadi@intel.com>]

Commit-ID:  4daa2a8093ecd1148270a1fc64e99f072b8c2901
Gitweb:     http://git.kernel.org/tip/4daa2a8093ecd1148270a1fc64e99f072b8c2901
Author:     Pallipadi, Venkatesh <venkatesh.pallipadi@intel.com>
AuthorDate: Wed, 24 Feb 2010 13:43:55 -0800
Committer:  H. Peter Anvin <hpa@zytor.com>
CommitDate: Mon, 1 Mar 2010 14:28:48 -0800

x86, pat: In rbt_memtype_check_insert(), update new->type only if valid

new->type should only change when there is a valid ret_type. Otherwise
the requested type and return type should be same.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
LKML-Reference: <20100224214355.GA16431@linux-os.sc.intel.com>
Tested-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
---
 arch/x86/mm/pat_rbtree.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/arch/x86/mm/pat_rbtree.c b/arch/x86/mm/pat_rbtree.c
index 9063f40..07de4cb 100644
--- a/arch/x86/mm/pat_rbtree.c
+++ b/arch/x86/mm/pat_rbtree.c
@@ -223,7 +223,9 @@ int rbt_memtype_check_insert(struct memtype *new, unsigned long *ret_type)
 						new->type, ret_type);
 
 	if (!err) {
-		new->type = *ret_type;
+		if (ret_type)
+			new->type = *ret_type;
+
 		memtype_rb_insert(&memtype_rbroot, new);
 	}
 	return err;