[PATCH 2/7] x86/range: check range in update range

[Yinghai Lu <yinghai@kernel.org>]

fend off wrong range

Signed-off-by: Yinghai Lu <yinghai@kernel.org>

---
 kernel/range.c |    9 +++++++++
 1 file changed, 9 insertions(+)

Index: linux-2.6/kernel/range.c
===================================================================
--- linux-2.6.orig/kernel/range.c
+++ linux-2.6/kernel/range.c
@@ -13,6 +13,9 @@
 
 int add_range(struct range *range, int az, int nr_range, u64 start, u64 end)
 {
+	if (start > end)
+		return nr_range;
+
 	/* Out of slots: */
 	if (nr_range >= az)
 		return nr_range;
@@ -30,6 +33,9 @@ int add_range_with_merge(struct range *r
 {
 	int i;
 
+	if (start > end)
+		return nr_range;
+
 	/* Try to merge it with old one: */
 	for (i = 0; i < nr_range; i++) {
 		u64 final_start, final_end;
@@ -59,6 +65,9 @@ void subtract_range(struct range *range,
 {
 	int i, j;
 
+	if (start > end)
+		return;
+
 	for (j = 0; j < az; j++) {
 		if (!range[j].end)
 			continue;