mm: pass address down to rmap ones

[safe/jmp/linux-2.6] / mm / mremap.c

diff --git a/mm/mremap.c b/mm/mremap.c
index 90e422c..8451908 100644 (file)
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -321,6 +321,7 @@ static unsigned long mremap_to(unsigned long addr,
        struct vm_area_struct *vma;
        unsigned long ret = -EINVAL;
        unsigned long charged = 0;
+       unsigned long map_flags;
 
        if (new_addr & ~PAGE_MASK)
                goto out;
@@ -358,9 +359,21 @@ static unsigned long mremap_to(unsigned long addr,
                goto out;
        }
 
-       ret = move_vma(vma, addr, old_len, new_len, new_addr);
+       map_flags = MAP_FIXED;
+       if (vma->vm_flags & VM_MAYSHARE)
+               map_flags |= MAP_SHARED;
+
+       ret = get_unmapped_area(vma->vm_file, new_addr, new_len, vma->vm_pgoff +
+                               ((addr - vma->vm_start) >> PAGE_SHIFT),
+                               map_flags);
        if (ret & ~PAGE_MASK)
-               vm_unacct_memory(charged);
+               goto out1;
+
+       ret = move_vma(vma, addr, old_len, new_len, new_addr);
+       if (!(ret & ~PAGE_MASK))
+               goto out;
+out1:
+       vm_unacct_memory(charged);
 
 out:
        return ret;
@@ -368,12 +381,14 @@ out:
 
 static int vma_expandable(struct vm_area_struct *vma, unsigned long delta)
 {
-       unsigned long max_addr = TASK_SIZE;
-       if (vma->vm_next)
-               max_addr = vma->vm_next->vm_start;
-       if (max_addr - vma->vm_end < delta)
+       unsigned long end = vma->vm_end + delta;
+       if (end < vma->vm_end) /* overflow */
+               return 0;
+       if (vma->vm_next && vma->vm_next->vm_start < end) /* intersection */
+               return 0;
+       if (get_unmapped_area(NULL, vma->vm_start, end - vma->vm_start,
+                             0, MAP_FIXED) & ~PAGE_MASK)
                return 0;
-       /* we need to do arch-specific checks here */
        return 1;
 }
 
@@ -471,7 +486,9 @@ unsigned long do_mremap(unsigned long addr,
                        map_flags |= MAP_SHARED;
 
                new_addr = get_unmapped_area(vma->vm_file, 0, new_len,
-                                       vma->vm_pgoff, map_flags);
+                                       vma->vm_pgoff +
+                                       ((addr - vma->vm_start) >> PAGE_SHIFT),
+                                       map_flags);
                if (new_addr & ~PAGE_MASK) {
                        ret = new_addr;
                        goto out;