fix the arch checks in MREMAP_FIXED case
Al Viro [Tue, 24 Nov 2009 13:43:52 +0000 (08:43 -0500)]
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

mm/mremap.c

index 9d07539..84efffb 100644 (file)
@@ -325,6 +325,7 @@ 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;
@@ -362,9 +363,23 @@ 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 = arch_mmap_check(new_addr, new_len, map_flags);
+       if (ret)
+               goto out1;
+       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;