1  /* Change the size of an allocated block.
       2     Copyright (C) 2017-2023 Free Software Foundation, Inc.
       3     This file is part of the GNU C Library.
       4  
       5     The GNU C Library is free software; you can redistribute it and/or
       6     modify it under the terms of the GNU Lesser General Public License as
       7     published by the Free Software Foundation; either version 2.1 of the
       8     License, or (at your option) any later version.
       9  
      10     The GNU C Library is distributed in the hope that it will be useful,
      11     but WITHOUT ANY WARRANTY; without even the implied warranty of
      12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      13     Lesser General Public License for more details.
      14  
      15     You should have received a copy of the GNU Lesser General Public
      16     License along with the GNU C Library; see the file COPYING.LIB.  If
      17     not, see <https://www.gnu.org/licenses/>.  */
      18  
      19  #include <errno.h>
      20  #include <stdlib.h>
      21  #include <malloc.h>
      22  
      23  void *
      24  __libc_reallocarray (void *optr, size_t nmemb, size_t elem_size)
      25  {
      26    size_t bytes;
      27    if (__builtin_mul_overflow (nmemb, elem_size, &bytes))
      28      {
      29        __set_errno (ENOMEM);
      30        return 0;
      31      }
      32    return realloc (optr, bytes);
      33  }
      34  libc_hidden_def (__libc_reallocarray)
      35  
      36  weak_alias (__libc_reallocarray, reallocarray)