[v2,1/4] resources: ensure alignment callback doesn't allocate below available start

Commit Message

Bjorn Helgaas Sept. 17, 2010, 10:32 p.m. UTC

None

Patch

diff --git a/kernel/resource.c b/kernel/resource.c
index 7b36976..ace2269 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -371,6 +371,7 @@  static int find_resource(struct resource *root, struct resource *new,
 {
 	struct resource *this = root->child;
 	struct resource tmp = *new;
+	resource_size_t start;
 
 	tmp.start = root->start;
 	/*
@@ -391,8 +392,13 @@  static int find_resource(struct resource *root, struct resource *new,
 		if (tmp.end > max)
 			tmp.end = max;
 		tmp.start = ALIGN(tmp.start, align);
-		if (alignf)
-			tmp.start = alignf(alignf_data, &tmp, size, align);
+		if (alignf) {
+			start = alignf(alignf_data, &tmp, size, align);
+			if (tmp.start <= start && start <= tmp.end)
+				tmp.start = start;
+			else
+				tmp.start = tmp.end;
+		}
 		if (tmp.start < tmp.end && tmp.end - tmp.start >= size - 1) {
 			new->start = tmp.start;
 			new->end = tmp.start + size - 1;