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authorBjorn Helgaas <bjorn.helgaas@hp.com>2010-10-26 15:41:23 -0600
committerJesse Barnes <jbarnes@virtuousgeek.org>2010-10-26 15:33:26 -0700
commit6909ba14c25b4db6be2ff89f4fa0fac2d70151a0 (patch)
tree1b663f1bba58f51b94bfc8372bea6d2c9295ec67
parent5d6b1fa301b13cc651ee717a9b518124dea2f814 (diff)
resources: ensure callback doesn't allocate outside available space
The alignment callback returns a proposed location, which may have been adjusted to avoid ISA aliases or for other architecture-specific reasons. We already had a check ("tmp.start < tmp.end") to make sure the callback doesn't return an area that extends past the available area. This patch reworks the check to make sure it doesn't return an area that extends either below or above the available area. Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
-rw-r--r--kernel/resource.c16
1 files changed, 11 insertions, 5 deletions
diff --git a/kernel/resource.c b/kernel/resource.c
index 26e9f2546923..89d50412508c 100644
--- 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)