1/* Auxiliary functions to issue the clone syscall.
2 Copyright (C) 2021-2022 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
7 License as published by the Free Software Foundation; either
8 version 2.1 of the 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; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#ifdef __linux__
20# include <support/check.h>
21# include <stackinfo.h> /* For _STACK_GROWS_{UP,DOWN}. */
22# include <xsched.h>
23
24pid_t
25xclone (int (*fn) (void *arg), void *arg, void *stack, size_t stack_size,
26 int flags)
27{
28 pid_t r = -1;
29
30# ifdef __ia64__
31 extern int __clone2 (int (*fn) (void *arg), void *stack, size_t stack_size,
32 int flags, void *arg, ...);
33 r = __clone2 (fn, stack, stack_size, flags, arg, /* ptid */ NULL,
34 /* tls */ NULL, /* ctid */ NULL);
35# else
36# if _STACK_GROWS_DOWN
37 r = clone (fn: fn, child_stack: stack + stack_size, flags: flags, arg: arg, /* ptid */ NULL,
38 /* tls */ NULL, /* ctid */ NULL);
39# elif _STACK_GROWS_UP
40 r = clone (fn, stack, flags, arg, /* ptid */ NULL, /* tls */ NULL, NULL);
41# endif
42# endif
43
44 if (r < 0)
45 FAIL_EXIT1 ("clone: %m");
46
47 return r;
48}
49#endif
50

source code of glibc/support/xclone.c