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  static bool __always_fail_morecore = false;
      19  
      20  /* Allocate INCREMENT more bytes of data space,
      21     and return the start of data space, or NULL on errors.
      22     If INCREMENT is negative, shrink data space.  */
      23  void *
      24  __glibc_morecore (ptrdiff_t increment)
      25  {
      26    if (__always_fail_morecore)
      27      return NULL;
      28  
      29    void *result = (void *) __sbrk (increment);
      30    if (result == (void *) -1)
      31      return NULL;
      32  
      33    return result;
      34  }
      35  #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_34)
      36  compat_symbol (libc, __glibc_morecore, __default_morecore, GLIBC_2_0);
      37  #endif