/* Copyright (C) 1996-2018 Free Software Foundation, Inc.

   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

   <http://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>

#define _ERRNO_H	1

#include <bits/errno.h>

/* int clone(int (*fn)(void *arg),            x0

	     void *child_stack,               x1

	     int flags,                       x2

	     void *arg,                       x3

	     pid_t *ptid,                     x4

	     struct user_desc *tls,           x5

             pid_t *ctid);                    x6

 */

        .text

ENTRY(__clone)

	DELOUSE (0)

	DELOUSE (1)

	DELOUSE (2)

	DELOUSE (3)

	DELOUSE (4)

	DELOUSE (5)

	DELOUSE (6)

	/* Save args for the child.  */

	mov	x10, x0

	mov	x11, x2

	mov	x12, x3

	/* Sanity check args.  */

	mov	x0, #-EINVAL

	cbz	x10, .Lsyscall_error

	cbz	x1, .Lsyscall_error

	/* Do the system call.  */

	/* X0:flags, x1:newsp, x2:parenttidptr, x3:newtls, x4:childtid.  */

	mov	x0, x2                  /* flags  */

	/* New sp is already in x1.  */

	mov	x2, x4			/* ptid  */

	mov	x3, x5			/* tls  */

	mov	x4, x6			/* ctid  */

	mov	x8, #SYS_ify(clone)

	svc	0x0

	cmp	x0, #0

	beq	thread_start

	blt	.Lsyscall_error

	RET

PSEUDO_END (__clone)

	.align 4

	.type thread_start, %function

thread_start:

	cfi_startproc

	cfi_undefined (x30)

	mov	x29, 0

	/* Pick the function arg and execute.  */

	mov	x0, x12

	blr	x10

	/* We are done, pass the return value through x0.  */

	mov	x8, #SYS_ify(exit)

	svc	0x0

	cfi_endproc

	.size thread_start, .-thread_start

libc_hidden_def (__clone)

weak_alias (__clone, clone)