haswell: fix overflow handling TOUUD
It's possible that the TOUUD can be set to less than
4GiB. When that is the case the size_k variable is
an extremely large value. Instead ensure TOUUD is greater
than 4GiB before adding said resources.
Change-Id: I456633d6210824e60665281538300fd15656b86d
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/3352
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
diff --git a/src/northbridge/intel/haswell/northbridge.c b/src/northbridge/intel/haswell/northbridge.c
index 5c1ab3e..45d967e 100644
--- a/src/northbridge/intel/haswell/northbridge.c
+++ b/src/northbridge/intel/haswell/northbridge.c
@@ -312,6 +312,7 @@
static void mc_add_dram_resources(device_t dev)
{
unsigned long base_k, size_k;
+ unsigned long touud_k;
unsigned long index;
struct resource *resource;
uint64_t mc_values[NUM_MAP_ENTRIES];
@@ -396,8 +397,9 @@
/* 4GiB -> TOUUD */
base_k = 4096 * 1024; /* 4GiB */
- size_k = (unsigned long)(mc_values[TOUUD_REG] >> 10) - base_k;
- if (size_k > 0)
+ touud_k = mc_values[TOUUD_REG] >> 10;
+ size_k = touud_k - base_k;
+ if (touud_k > base_k)
ram_resource(dev, index++, base_k, size_k);
/* Reserve everything between A segment and 1MB: