From 6909ba14c25b4db6be2ff89f4fa0fac2d70151a0 Mon Sep 17 00:00:00 2001 From: Bjorn Helgaas Date: Tue, 26 Oct 2010 15:41:23 -0600 Subject: 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 Signed-off-by: Jesse Barnes --- kernel/resource.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) (limited to 'kernel/resource.c') 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) -- cgit v1.2.3