1 /* Wrapper around clone system call. 64 bit S/390 version.
2 Copyright (C) 2001-2023 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
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.
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.
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/>. */
19 /* clone is even more special than fork as it mucks with stacks
20 and invokes a function in the right context after its all over. */
25 #include <bits/errno.h>
27 /* int __clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg,
28 pid_t *parent_tid, void *tls, pid_t *child_tid); */
29 /* sys_clone (void *child_stack, unsigned long flags,
30 pid_t *parent_tid, pid_t *child_tid, void *tls); */
34 stmg %r6,%r7,48(%r15) /* Save registers. */
37 ltgr %r7,%r2 /* check fn and move to %r7 */
38 jz error /* no NULL function pointers */
39 lghi %r0,-16 /* Align the child_stack to a ... */
40 ngr %r3,%r0 /* double word boundary and ... */
41 jz error /* avoid NULL stack pointers. */
42 lgr %r0,%r5 /* move *arg out of the way */
43 lgr %r2,%r3 /* move child_stack to %r2 */
44 lgr %r3,%r4 /* move flags to %r3 */
45 lgr %r4,%r6 /* move parent_tid to %r4 */
46 lg %r5,168(%r15) /* load child_tid from stack */
47 lg %r6,160(%r15) /* load tls from stack */
48 lghi %r1,SYS_ify (clone)
50 ltgr %r2,%r2 /* check return code */
52 lmg %r6,%r7,48(%r15) /* Restore registers. */
53 jgm SYSCALL_ERROR_LABEL
57 jg SYSCALL_ERROR_LABEL
62 /* Mark r14 as undefined in order to stop unwinding here! */
64 /* fn is in gpr 7, arg in gpr 0 */
65 lgr %r2,%r0 /* set first parameter to void *arg */
66 aghi %r15,-160 /* make room on the stack for the save area */
68 basr %r14,%r7 /* jump to fn */
72 libc_hidden_def (__clone)
73 weak_alias (__clone, clone)