[PATCH 1/2] x86: Sanity check the e820 against the SRAT table using e820 map only

Yinghai Lu
2009-05-08T07:38:38Z

node_cover_memory() sanity checks the SRAT table by ensuring that all
PXMs cover the memory reported in the e820. However, when calculating
the size of the holes in the e820, it uses the early_node_map[] which
contains information taken from both SRAT and e820. If the SRAT is
missing an entry, then it is not detected that the SRAT table is
incorrect and missing entries.

This patch uses the e820 map to calculate the holes instead of
early_node_map[].

comment is from Mel.

[ Impact: reject wrong SRAT tables ]

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Mel Gorman <mel@csn.ul.ie>

---
arch/x86/mm/srat_64.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

Index: linux-2.6/arch/x86/mm/srat_64.c
===================================================================
--- linux-2.6.orig/arch/x86/mm/srat_64.c
+++ linux-2.6/arch/x86/mm/srat_64.c
@@ -345,7 +345,7 @@ static int __init nodes_cover_memory(con
pxmram = 0;
}

- e820ram = max_pfn - absent_pages_in_range(0, max_pfn);
+ e820ram = max_pfn - (e820_hole_size(0, max_pfn<<PAGE_SHIFT)>>PAGE_SHIFT);
/* We seem to lose 3 pages somewhere. Allow a bit of slack. */
if ((long)(e820ram - pxmram) >= 1*1024*1024) {