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/* Wrapper around clone system call. 64 bit S/390 version.
Copyright (C) 2001-2021 Free Software Foundation, Inc.
Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com).
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
/* clone is even more special than fork as it mucks with stacks
and invokes a function in the right context after its all over. */
#include <sysdep.h>
#include <tls.h>
#define _ERRNO_H 1
#include <bits/errno.h>
/* int __clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg,
pid_t *parent_tid, void *tls, pid_t *child_tid); */
/* sys_clone (void *child_stack, unsigned long flags,
pid_t *parent_tid, pid_t *child_tid, void *tls); */
.text
ENTRY(__clone)
stg %r6,48(%r15) /* store %r6 to save area */
cfi_offset (%r6,-112)
ltgr %r1,%r2 /* check fn and move to %r1 */
jz error /* no NULL function pointers */
lghi %r0,-16 /* Align the child_stack to a ... */
ngr %r3,%r0 /* double word boundary and ... */
jz error /* avoid NULL stack pointers. */
lgr %r0,%r5 /* move *arg out of the way */
lgr %r2,%r3 /* move child_stack to %r2 */
lgr %r3,%r4 /* move flags to %r3 */
lgr %r4,%r6 /* move parent_tid to %r4 */
lg %r5,168(%r15) /* load child_tid from stack */
lg %r6,160(%r15) /* load tls from stack */
svc SYS_ify(clone)
ltgr %r2,%r2 /* check return code */
jz thread_start
lg %r6,48(%r15) /* restore %r6 */
jgm SYSCALL_ERROR_LABEL
br %r14
error:
lghi %r2,-EINVAL
jg SYSCALL_ERROR_LABEL
PSEUDO_END (__clone)
thread_start:
cfi_startproc
/* Mark r14 as undefined in order to stop unwinding here! */
cfi_undefined (r14)
/* fn is in gpr 1, arg in gpr 0 */
lgr %r2,%r0 /* set first parameter to void *arg */
aghi %r15,-160 /* make room on the stack for the save area */
xc 0(8,%r15),0(%r15)
basr %r14,%r1 /* jump to fn */
DO_CALL (exit, 1)
cfi_endproc
libc_hidden_def (__clone)
weak_alias (__clone, clone)
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