1 files changed, 50 insertions, 0 deletions

diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index 2d6d682c206a..25d9a11eb617 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -568,6 +568,55 @@ void __init iotable_init(struct map_desc *io_desc, int nr)
                 create_mapping(io_desc + i);
 }
 
+static int __init check_membank_valid(struct membank *mb)
+{
+        /*
+         * Check whether this memory region has non-zero size.
+         */
+        if (mb->size == 0)
+                return 0;
+
+        /*
+         * Check whether this memory region would entirely overlap
+         * the vmalloc area.
+         */
+        if (phys_to_virt(mb->start) >= VMALLOC_MIN) {
+                printk(KERN_NOTICE "Ignoring RAM at %.8lx-%.8lx "
+                        "(vmalloc region overlap).\n",
+                        mb->start, mb->start + mb->size - 1);
+                return 0;
+        }
+
+        /*
+         * Check whether this memory region would partially overlap
+         * the vmalloc area.
+         */
+        if (phys_to_virt(mb->start + mb->size) < phys_to_virt(mb->start) ||
+            phys_to_virt(mb->start + mb->size) > VMALLOC_MIN) {
+                unsigned long newsize = VMALLOC_MIN - phys_to_virt(mb->start);
+
+                printk(KERN_NOTICE "Truncating RAM at %.8lx-%.8lx "
+                        "to -%.8lx (vmalloc region overlap).\n",
+                        mb->start, mb->start + mb->size - 1,
+                        mb->start + newsize - 1);
+                mb->size = newsize;
+        }
+
+        return 1;
+}
+
+static void __init sanity_check_meminfo(struct meminfo *mi)
+{
+        int i;
+        int j;
+
+        for (i = 0, j = 0; i < mi->nr_banks; i++) {
+                if (check_membank_valid(&mi->bank[i]))
+                        mi->bank[j++] = mi->bank[i];
+        }
+        mi->nr_banks = j;
+}
+
 static inline void prepare_page_table(struct meminfo *mi)
 {
         unsigned long addr;
@@ -753,6 +802,7 @@ void __init paging_init(struct meminfo *mi, struct machine_desc *mdesc)
         void *zero_page;
 
         build_mem_type_table();
+        sanity_check_meminfo(mi);
         prepare_page_table(mi);
         bootmem_init(mi);
         devicemaps_init(mdesc);