x86: Sanity check the e820 against the SRAT table using e820 map only

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 incorrect SRAT tables ]

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <4A03E10C.60906@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/arch/x86/mm/srat_64.c b/arch/x86/mm/srat_64.c
index 01765955baaf66922ad70a959c9875f60fcad56e..c7a18aaccf8d21777bfa7a1b59b07ed81e6d7261 100644 (file)
--- a/arch/x86/mm/srat_64.c
+++ b/arch/x86/mm/srat_64.c
@@ -345,7 +345,7 @@ static int __init nodes_cover_memory(const struct bootnode *nodes)
                        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) {
                printk(KERN_ERR