VM: add "vm_mmap()" helper function

[linux-flexiantxendom0-3.2.10.git] / mm / mmap.c

diff --git a/mm/mmap.c b/mm/mmap.c
index 4af45f5..b38b47e 100644 (file)
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -953,7 +953,7 @@ static inline unsigned long round_hint_to_min(unsigned long hint)
  * The caller must hold down_write(&current->mm->mmap_sem).
  */
 
-unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
+static unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
                        unsigned long len, unsigned long prot,
                        unsigned long flags, unsigned long pgoff)
 {
@@ -1089,7 +1089,32 @@ unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
 
        return mmap_region(file, addr, len, flags, vm_flags, pgoff);
 }
-EXPORT_SYMBOL(do_mmap_pgoff);
+
+unsigned long do_mmap(struct file *file, unsigned long addr,
+       unsigned long len, unsigned long prot,
+       unsigned long flag, unsigned long offset)
+{
+       if (unlikely(offset + PAGE_ALIGN(len) < offset))
+               return -EINVAL;
+       if (unlikely(offset & ~PAGE_MASK))
+               return -EINVAL;
+       return do_mmap_pgoff(file, addr, len, prot, flag, offset >> PAGE_SHIFT);
+}
+EXPORT_SYMBOL(do_mmap);
+
+unsigned long vm_mmap(struct file *file, unsigned long addr,
+       unsigned long len, unsigned long prot,
+       unsigned long flag, unsigned long offset)
+{
+       unsigned long ret;
+       struct mm_struct *mm = current->mm;
+
+       down_write(&mm->mmap_sem);
+       ret = do_mmap(file, addr, len, prot, flag, offset);
+       up_write(&mm->mmap_sem);
+       return ret;
+}
+EXPORT_SYMBOL(vm_mmap);
 
 SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len,
                unsigned long, prot, unsigned long, flags,