1 files changed, 25 insertions, 0 deletions

diff --git a/arch/um/sys-i386/unmap.c b/arch/um/sys-i386/unmap.c
new file mode 100644
index 000000000000..136875263d27
--- /dev/null
+++ b/arch/um/sys-i386/unmap.c
@@ -0,0 +1,25 @@
+/*
+ * Copyright (C) 2000 Jeff Dike (jdike@karaya.com)
+ * Licensed under the GPL
+ */
+
+#include <linux/mman.h>
+#include <asm/unistd.h>
+
+static int errno;
+
+static inline _syscall2(int,munmap,void *,start,size_t,len)
+static inline _syscall6(void *,mmap2,void *,addr,size_t,len,int,prot,int,flags,int,fd,off_t,offset)
+int switcheroo(int fd, int prot, void *from, void *to, int size)
+{
+        if(munmap(to, size) < 0){
+                return(-1);
+        }
+        if(mmap2(to, size, prot, MAP_SHARED | MAP_FIXED, fd, 0) != to){
+                return(-1);
+        }
+        if(munmap(from, size) < 0){
+                return(-1);
+        }
+        return(0);
+}