resources: ensure callback doesn't allocate outside available space

[pandora-kernel.git] / kernel / resource.c

diff --git a/kernel/resource.c b/kernel/resource.c
index 26e9f25..89d5041 100644 (file)
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -374,6 +374,11 @@ static void resource_clip(struct resource *res, resource_size_t min,
                res->end = max;
 }
 
+static bool resource_contains(struct resource *res1, struct resource *res2)
+{
+       return res1->start <= res2->start && res1->end >= res2->end;
+}
+
 /*
  * Find empty slot in the resource tree given range and alignment.
  */
@@ -387,7 +392,7 @@ static int find_resource(struct resource *root, struct resource *new,
                         void *alignf_data)
 {
        struct resource *this = root->child;
-       struct resource tmp = *new;
+       struct resource tmp = *new, alloc;
 
        tmp.start = root->start;
        /*
@@ -407,10 +412,11 @@ static int find_resource(struct resource *root, struct resource *new,
                resource_clip(&tmp, min, max);
                tmp.start = ALIGN(tmp.start, align);
 
-               tmp.start = alignf(alignf_data, &tmp, size, align);
-               if (tmp.start < tmp.end && tmp.end - tmp.start >= size - 1) {
-                       new->start = tmp.start;
-                       new->end = tmp.start + size - 1;
+               alloc.start = alignf(alignf_data, &tmp, size, align);
+               alloc.end = alloc.start + size - 1;
+               if (resource_contains(&tmp, &alloc)) {
+                       new->start = alloc.start;
+                       new->end = alloc.end;
                        return 0;
                }
                if (!this)