[patch] mm: nobootmem: fix sign extend problem in __free_pages_memory()

From: Russ Anderson
Date: Mon May 07 2012 - 15:32:04 EST


Systems with 8 TBytes of memory or greater can hit a problem
where only the the first 8 TB of memory shows up. This is
due to "int i" being smaller than "unsigned long start_aligned",
causing the high bits to be dropped.

The fix is to change i to unsigned long to match start_aligned
and end_aligned.

Thanks to Jack Steiner (steiner@xxxxxxx) for assistance tracking
this down.

Signed-off-by: Russ Anderson <rja@xxxxxxx>

---
mm/nobootmem.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

Index: linux/mm/nobootmem.c
===================================================================
--- linux.orig/mm/nobootmem.c 2012-05-05 08:39:39.470845187 -0500
+++ linux/mm/nobootmem.c 2012-05-05 08:39:42.714784530 -0500
@@ -82,8 +82,7 @@ void __init free_bootmem_late(unsigned l

static void __init __free_pages_memory(unsigned long start, unsigned long end)
{
- int i;
- unsigned long start_aligned, end_aligned;
+ unsigned long i, start_aligned, end_aligned;
int order = ilog2(BITS_PER_LONG);

start_aligned = (start + (BITS_PER_LONG - 1)) & ~(BITS_PER_LONG - 1);
--
Russ Anderson, OS RAS/Partitioning Project Lead
SGI - Silicon Graphics Inc rja@xxxxxxx
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