[U-Boot] [PATCH] pci: fix overflow in __pci_hose_bus_to_phys w/ large RAM

Stephen Warren
2014-08-11T22:09:28Z

From: Stephen Warren <swarren@nvidia.com>

If a 32-bit system has 2GB of RAM, and the base address of that RAM is
2GB, then start+size will overflow a 32-bit value (to a value of 0).

To avoid such an overflow, convert __pci_hose_bus_to_phys() to calculate
the offset of a bus address into a PCI region, rather than comparing a
bus address against the end of a PCI region.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
---
drivers/pci/pci.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index ed113bf4022f..4fd9c532b3fb 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -323,7 +323,7 @@ int __pci_hose_bus_to_phys(struct pci_controller *hose,
continue;

if (bus_addr >= res->bus_start &&
- bus_addr < res->bus_start + res->size) {
+ (bus_addr - res->bus_start) < res->size) {
*pa = (bus_addr - res->bus_start + res->phys_start);
return 0;
}
--
1.9.1