1  /* Copyright (C) 1991-2023 Free Software Foundation, Inc.
       2     This file is part of the GNU C Library.
       3  
       4     The GNU C Library is free software; you can redistribute it and/or
       5     modify it under the terms of the GNU Lesser General Public
       6     License as published by the Free Software Foundation; either
       7     version 2.1 of the License, or (at your option) any later version.
       8  
       9     The GNU C Library is distributed in the hope that it will be useful,
      10     but WITHOUT ANY WARRANTY; without even the implied warranty of
      11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      12     Lesser General Public License for more details.
      13  
      14     You should have received a copy of the GNU Lesser General Public
      15     License along with the GNU C Library; if not, see
      16     <https://www.gnu.org/licenses/>.  */
      17  
      18  #include <errno.h>
      19  #include <hurd.h>
      20  #include <unistd.h>
      21  
      22  /* Extend the process's data space by INCREMENT.
      23     If INCREMENT is negative, shrink data space by - INCREMENT.
      24     Return the address of the start of the new data space, or -1 for errors.  */
      25  void *
      26  __sbrk (intptr_t increment)
      27  {
      28    void *result;
      29  
      30    HURD_CRITICAL_BEGIN;
      31    __mutex_lock (&_hurd_brk_lock);
      32    result = (void *) _hurd_brk;
      33    if (increment != 0 && _hurd_set_brk (_hurd_brk + increment) < 0)
      34      result = (void *) -1;
      35    __mutex_unlock (&_hurd_brk_lock);
      36    HURD_CRITICAL_END;
      37  
      38    return result;
      39  }
      40  libc_hidden_def (__sbrk)
      41  weak_alias (__sbrk, sbrk)