1 files changed, 29 insertions, 0 deletions

diff --git a/mm/nommu.c b/mm/nommu.c
index 23fb033e596d..1f60194d9b9b 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -45,6 +45,7 @@ int heap_stack_gap = 0;
 
 EXPORT_SYMBOL(mem_map);
 EXPORT_SYMBOL(__vm_enough_memory);
+EXPORT_SYMBOL(num_physpages);
 
 /* list of shareable VMAs */
 struct rb_root nommu_vma_tree = RB_ROOT;
@@ -826,6 +827,11 @@ unsigned long do_mmap_pgoff(struct file *file,
                 unsigned long pglen = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
                 unsigned long vmpglen;
 
+                /* suppress VMA sharing for shared regions */
+                if (vm_flags & VM_SHARED &&
+                    capabilities & BDI_CAP_MAP_DIRECT)
+                        goto dont_share_VMAs;
+
                 for (rb = rb_first(&nommu_vma_tree); rb; rb = rb_next(rb)) {
                         vma = rb_entry(rb, struct vm_area_struct, vm_rb);
 
@@ -859,6 +865,7 @@ unsigned long do_mmap_pgoff(struct file *file,
                         goto shared;
                 }
 
+        dont_share_VMAs:
                 vma = NULL;
 
                 /* obtain the address at which to make a shared mapping
@@ -1193,6 +1200,28 @@ void unmap_mapping_range(struct address_space *mapping,
 EXPORT_SYMBOL(unmap_mapping_range);
 
 /*
+ * ask for an unmapped area at which to create a mapping on a file
+ */
+unsigned long get_unmapped_area(struct file *file, unsigned long addr,
+                                unsigned long len, unsigned long pgoff,
+                                unsigned long flags)
+{
+        unsigned long (*get_area)(struct file *, unsigned long, unsigned long,
+                                  unsigned long, unsigned long);
+
+        get_area = current->mm->get_unmapped_area;
+        if (file && file->f_op && file->f_op->get_unmapped_area)
+                get_area = file->f_op->get_unmapped_area;
+
+        if (!get_area)
+                return -ENOSYS;
+
+        return get_area(file, addr, len, pgoff, flags);
+}
+
+EXPORT_SYMBOL(get_unmapped_area);
+
+/*
  * Check that a process has enough memory to allocate a new virtual
  * mapping. 0 means there is enough memory for the allocation to
  * succeed and -ENOMEM implies there is not.