1  /* mremap.c -- version of mremap for gold.  */
       2  
       3  /* Copyright (C) 2009-2023 Free Software Foundation, Inc.
       4     Written by Ian Lance Taylor <iant@google.com>.
       5  
       6     This file is part of gold.
       7  
       8     This program is free software; you can redistribute it and/or modify
       9     it under the terms of the GNU General Public License as published by
      10     the Free Software Foundation; either version 3 of the License, or
      11     (at your option) any later version.
      12  
      13     This program is distributed in the hope that it will be useful,
      14     but WITHOUT ANY WARRANTY; without even the implied warranty of
      15     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      16     GNU General Public License for more details.
      17  
      18     You should have received a copy of the GNU General Public License
      19     along with this program; if not, write to the Free Software
      20     Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
      21     MA 02110-1301, USA.  */
      22  
      23  #include "config.h"
      24  #include "ansidecl.h"
      25  
      26  #include <errno.h>
      27  #include <string.h>
      28  #include <sys/types.h>
      29  
      30  #ifdef HAVE_SYS_MMAN_H
      31  #include <sys/mman.h>
      32  #endif
      33  
      34  extern void *gold_mremap (void *, size_t, size_t, int);
      35  
      36  #ifdef HAVE_MMAP
      37  
      38  /* This file implements mremap for systems which don't have it.  The
      39     gold code requires support for mmap.  However, there are systems
      40     which have mmap but not mremap.  This is not a general replacement
      41     for mremap; it only supports the features which are required for
      42     gold.  In particular, we assume that the MREMAP_MAYMOVE flag is
      43     set.  */
      44  
      45  /* Some BSD systems still use MAP_ANON instead of MAP_ANONYMOUS.  */
      46  
      47  #ifndef MAP_ANONYMOUS
      48  # define MAP_ANONYMOUS MAP_ANON
      49  #endif
      50  
      51  void *
      52  gold_mremap (void *old_address, size_t old_size, size_t new_size,
      53  	     int flags ATTRIBUTE_UNUSED)
      54  {
      55    void *ret;
      56  
      57    ret = mmap (0, new_size, PROT_READ | PROT_WRITE,
      58  	      MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
      59    if (ret == MAP_FAILED)
      60      return ret;
      61    memcpy (ret, old_address,
      62  	  old_size < new_size ? old_size : new_size);
      63    (void) munmap (old_address, old_size);
      64    return ret;
      65  }
      66  
      67  #else /* !defined(HAVE_MMAP) */
      68  
      69  #ifndef MAP_FAILED
      70  #define MAP_FAILED ((void *) -1)
      71  #endif
      72  
      73  #ifndef ENOSYS
      74  #define ENOSYS EINVAL
      75  #endif
      76  
      77  void *
      78  gold_mremap (void *old_address ATTRIBUTE_UNUSED,
      79  	     size_t old_size ATTRIBUTE_UNUSED,
      80  	     size_t new_size ATTRIBUTE_UNUSED,
      81  	     int flags ATTRIBUTE_UNUSED)
      82  {
      83    errno = ENOSYS;
      84    return MAP_FAILED;
      85  }
      86  
      87  #endif /* !defined(HAVE_MMAP) */