[PATCH] pci enumeration on ixp2000: overflow in kernel/resource.c

IXP2000 (ARM-based) platforms use a separate 'struct resource' for PCI MEM
space.  Resource allocation for PCI BARs always fails because the 'root'
resource (the IXP2000 PCI MEM resource) always has the entire address space
(00000000-ffffffff) free, and find_resource() calculates the size of that
range as ffffffff-00000000+1=0, so all allocations fail because it thinks
there is no space.

(akpm: pls. double-check)

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/kernel/resource.c b/kernel/resource.c
index 35c99ac02c7cf1408e03cfa4198a0a6786b3ac58..52f696f11adfe68bbe5785e997f290071e8d6cf1 100644 (file)
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -266,7 +266,7 @@ static int find_resource(struct resource *root, struct resource *new,
                new->start = (new->start + align - 1) & ~(align - 1);
                if (alignf)
                        alignf(alignf_data, new, size, align);
-               if (new->start < new->end && new->end - new->start + 1 >= size) {
+               if (new->start < new->end && new->end - new->start >= size - 1) {
                        new->end = new->start + size - 1;
                        return 0;
                }