1 /* Copyright (C) 1991-2022 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 *
__sbrk(intptr_t increment)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)
42