[PATCH 02/38] x86: check range in update range

[Yinghai Lu <yinghai@kernel.org>]

fend off wrong range

so later could use it with 32bit amd_bus/intel_bus, and it could have cap_resource.

-v2: update comments

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
---
 kernel/range.c |    9 +++++++++
 1 files changed, 9 insertions(+), 0 deletions(-)

diff --git a/kernel/range.c b/kernel/range.c
index 46a10c8..71e0021 100644
--- a/kernel/range.c
+++ b/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 *range, int az, int nr_range,
 {
 	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 az, u64 start, u64 end)
 {
 	int i, j;
 
+	if (start > end)
+		return;
+
 	for (j = 0; j < az; j++) {
 		if (!range[j].end)
 			continue;
-- 
1.6.4.2