arch/um/sys-i386/unmap.c

   1 /*
   2  * Copyright (C) 2000 Jeff Dike (jdike@karaya.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #include <linux/mman.h>
   7 #include <asm/unistd.h>
   8
   9 static int errno;
  10
  11 static inline _syscall2(int,munmap,void *,start,size_t,len)
  12 static inline _syscall6(void *,mmap2,void *,addr,size_t,len,int,prot,int,flags,int,fd,off_t,offset)
  13 int switcheroo(int fd, int prot, void *from, void *to, int size)
  14 {
  15         if(munmap(to, size) < 0){
  16                 return(-1);
  17         }
  18         if(mmap2(to, size, prot, MAP_SHARED | MAP_FIXED, fd, 0) == (void*) -1 ){
  19                 return(-1);
  20         }
  21         if(munmap(from, size) < 0){
  22                 return(-1);
  23         }
  24         return(0);
  25 }