[PATCH] hugetlb fix

Patch from Rohit Seth

It fixes the problem which Andrea noted in his initial review of the
hugetlb code:

"In short doing "addr = vma->vm_end" and then checking if vm_end + len
 is below vm_next->vm_start is broken, because there's no guarantee
 that "addr" will be a largepage aligned address.  the LPAGE_ALIGN in
 found_addr should be dropped becaue moving the addr ahead without
 checking that addr+len doesn't then fall into a vma, will generate
 do_munmaps and in turn userspace mem corruption."

arch/i386/kernel/sys_i386.c

@@ -272,10 +272,9 @@ get_addr(unsigned long addr, unsigned long len)
 			return -ENOMEM;
 		if (!vma || ((addr + len) < vma->vm_start))
 			goto found_addr;
-		addr = vma->vm_end;
+		addr = HPAGE_ALIGN(vma->vm_end);
 	}
 found_addr:
-	addr = HPAGE_ALIGN(addr);
 	return addr;
 }