1 files changed, 11 insertions, 3 deletions

diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
index 996ee2bf7bdb..c3e92912c3fb 100644
--- a/arch/x86/xen/p2m.c
+++ b/arch/x86/xen/p2m.c
@@ -396,6 +396,7 @@ unsigned long __init xen_revector_p2m_tree(void)
         unsigned long va_start;
         unsigned long va_end;
         unsigned long pfn;
+        unsigned long pfn_free = 0;
         unsigned long *mfn_list = NULL;
         unsigned long size;
 
@@ -442,11 +443,18 @@ unsigned long __init xen_revector_p2m_tree(void)
                 if (mid_p >= (unsigned long *)va_start && mid_p <= (unsigned long *)va_end) {
                         unsigned long *new;
 
-                        new = &mfn_list[pfn];
+                        if (pfn_free  > (size / sizeof(unsigned long))) {
+                                WARN(1, "Only allocated for %ld pages, but we want %ld!\n",
+                                     size / sizeof(unsigned long), pfn_free);
+                                return 0;
+                        }
+                        new = &mfn_list[pfn_free];
 
                         copy_page(new, mid_p);
-                        p2m_top[topidx][mididx] = &mfn_list[pfn];
-                        p2m_top_mfn_p[topidx][mididx] = virt_to_mfn(&mfn_list[pfn]);
+                        p2m_top[topidx][mididx] = &mfn_list[pfn_free];
+                        p2m_top_mfn_p[topidx][mididx] = virt_to_mfn(&mfn_list[pfn_free]);
+
+                        pfn_free += P2M_PER_PAGE;
 
                 }
                 /* This should be the leafs allocated for identity from _brk. */