1/* Copyright (C) 1991-2021 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#if defined(SHARED) || defined(USE_MTAG)
19static bool __always_fail_morecore = false;
20#endif
21
22/* Allocate INCREMENT more bytes of data space,
23 and return the start of data space, or NULL on errors.
24 If INCREMENT is negative, shrink data space. */
25void *
26__glibc_morecore (ptrdiff_t increment)
27{
28#if defined(SHARED) || defined(USE_MTAG)
29 if (__always_fail_morecore)
30 return NULL;
31#endif
32
33 void *result = (void *) __sbrk (increment);
34 if (result == (void *) -1)
35 return NULL;
36
37 return result;
38}
39#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_34)
40compat_symbol (libc, __glibc_morecore, __default_morecore, GLIBC_2_0);
41#endif
42