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/* Copyright (C) 2001, 2005 Free Software Foundation, Inc.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
/* 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 <features.h>
#include <sysdep.h>
#define _ERRNO_H 1
#include <bits/errno.h>
#ifdef RESET_PID
#include <tls.h>
#endif
#define __ASSEMBLY__
#include <linux/sched.h>
/* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg,
a2 a3 a4 a5
pid_t *ptid, struct user_desc *tls, pid_t *ctid)
a6 a7 16(sp)
*/
.text
ENTRY (__clone)
/* Sanity check arguments. */
beqz a2, .Leinval /* no NULL function pointers */
beqz a3, .Leinval /* no NULL stack pointers */
/* a2 and a3 are candidates for destruction by system-call return
parameters. We don't need the stack pointer after the system
call. We trust that the kernel will preserve a6, a7 and a9. */
mov a9, a5 /* save function argument */
mov a5, a7
mov a7, a2 /* save function pointer */
mov a8, a6 /* use a8 as a temp */
mov a6, a4
mov a4, a8
l32i a8, a1, 16 /* child_tid */
movi a2, SYS_ify(clone)
/* syscall(NR_clone,clone_flags, usp, parent_tid, child_tls, child_tid)
a2 a6 a3 a4 a5 a8
*/
syscall
bltz a2, SYSCALL_ERROR_LABEL
beqz a2, .Lthread_start
/* fall through for parent */
.Lpseudo_end:
retw
.Leinval:
movi a2, -EINVAL
j SYSCALL_ERROR_LABEL
.Lthread_start:
#if CLONE_THREAD != 0x00010000 || CLONE_VM != 0x00000100
# error invalid values for CLONE_THREAD or CLONE_VM
#endif
#ifdef RESET_PID
bbsi.l a6, 16, .Lskip_restore_pid /* CLONE_THREAD = 0x00010000 */
movi a2, -1
bbsi a6, 8, .Lgotpid /* CLONE_VM = 0x00000100 */
movi a2, SYS_ify(getpid)
syscall
.Lgotpid:
rur a3, threadptr
movi a0, TLS_PRE_TCB_SIZE
sub a3, a3, a0
s32i a2, a3, PID
s32i a2, a3, TID
.Lskip_restore_pid:
#endif
/* start child thread */
movi a0, 0 /* terminate the stack frame */
mov a6, a9 /* load up the 'arg' parameter */
callx4 a7 /* call the user's function */
/* Call _exit. Note that any return parameter from the user's
function in a6 is seen as inputs to _exit. */
#ifdef PIC
movi a2, _exit@PLT
#else
movi a2, _exit
#endif
callx4 a2
PSEUDO_END (__clone)
weak_alias (__clone, clone)
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