Subject: [to-be-updated] arch-x86-mm-numa_32c-fix-the-initialization-of-physnode_map.patch removed from -mm tree
To: ptesarik@xxxxxxx,mm-commits@xxxxxxxxxxxxxxx
From: akpm@xxxxxxxxxxxxxxxxxxxx
Date: Mon, 03 Feb 2014 15:42:45 -0800
The patch titled
Subject: arch/x86/mm/numa_32.c: fix the initialization of physnode_map
has been removed from the -mm tree. Its filename was
arch-x86-mm-numa_32c-fix-the-initialization-of-physnode_map.patch
This patch was dropped because an updated version will be merged
------------------------------------------------------
From: Petr Tesarik <ptesarik@xxxxxxx>
Subject: arch/x86/mm/numa_32.c: fix the initialization of physnode_map
With DISCONTIGMEM, the mapping between a pfn and its owning node is
initialized using data provided by the BIOS. However, the initialization
may fail if the extents are not aligned to section boundary (64M).
The symptom of this bug is an early boot failure in pfn_to_page(), as it
tries to access NODE_DATA(__nid) using index from an unitialized element
of the physnode_map[] array.
While the bug is always present, it is more likely to be hit in kdump
kernels on large machines, because:
1. The memory map for a kdump kernel is specified as exactmap, and
exactmap is more likely to be unaligned.
2. Large reservations are more likely to span across a 64M boundary.
Signed-off-by: Petr Tesarik <ptesarik@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/x86/mm/numa_32.c | 2 ++
1 file changed, 2 insertions(+)
diff -puN arch/x86/mm/numa_32.c~arch-x86-mm-numa_32c-fix-the-initialization-of-physnode_map arch/x86/mm/numa_32.c
--- a/arch/x86/mm/numa_32.c~arch-x86-mm-numa_32c-fix-the-initialization-of-physnode_map
+++ a/arch/x86/mm/numa_32.c
@@ -52,6 +52,8 @@ void memory_present(int nid, unsigned lo
nid, start, end);
printk(KERN_DEBUG " Setting physnode_map array to node %d for pfns:\n", nid);
printk(KERN_DEBUG " ");
+ pfn = round_down(pfn, PAGES_PER_SECTION);
+ end = round_up(end, PAGES_PER_SECTION);
for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION) {
physnode_map[pfn / PAGES_PER_SECTION] = nid;
printk(KERN_CONT "%lx ", pfn);
_
Patches currently in -mm which might be from ptesarik@xxxxxxx are
linux-next.patch
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