Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6

1 files changed, 10 insertions, 0 deletions

diff --git a/mm/sparse.c b/mm/sparse.c
index f6a43c09c322..98d6b39c3472 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -149,8 +149,18 @@ static inline int sparse_early_nid(struct mem_section *section)
 /* Record a memory area against a node. */
 void __init memory_present(int nid, unsigned long start, unsigned long end)
 {
+        unsigned long max_arch_pfn = 1UL << (MAX_PHYSMEM_BITS-PAGE_SHIFT);
         unsigned long pfn;
 
+        /*
+         * Sanity checks - do not allow an architecture to pass
+         * in larger pfns than the maximum scope of sparsemem:
+         */
+        if (start >= max_arch_pfn)
+                return;
+        if (end >= max_arch_pfn)
+                end = max_arch_pfn;
+
         start &= PAGE_SECTION_MASK;
         for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION) {
                 unsigned long section = pfn_to_section_nr(pfn);