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

   This file is part of the GNU C Library.

   Contributed by Ralf Baechle <ralf@linux-mips.org>, 1996.

   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 <sys/asm.h>

#include <sysdep.h>

#define _ERRNO_H	1

#include <bits/errno.h>

#include <tls.h>

/* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg,

	     void *parent_tidptr, void *tls, void *child_tidptr) */

	.text

	.set		nomips16

#if _MIPS_SIM == _ABIO32

# define EXTRA_LOCALS 1

#else

# define EXTRA_LOCALS 0

#endif

LOCALSZ= 4

FRAMESZ= (((NARGSAVE+LOCALSZ)*SZREG)+ALSZ)&ALMASK

GPOFF= FRAMESZ-(1*SZREG)

NESTED(__clone,4*SZREG,sp)

#ifdef __PIC__

	SETUP_GP

#endif

	PTR_SUBU sp, FRAMESZ

	cfi_adjust_cfa_offset (FRAMESZ)

	SETUP_GP64_STACK (GPOFF, __clone)

#ifdef __PIC__

	SAVE_GP (GPOFF)

#endif

#ifdef PROF

	.set		noat

	move		$1,ra

	jal		_mcount

	.set		at

#endif

	/* Sanity check arguments.  */

	li		v0,EINVAL

	beqz		a0,L(error)	/* No NULL function pointers.  */

	beqz		a1,L(error)	/* No NULL stack pointers.  */

	PTR_SUBU	a1,32		/* Reserve argument save space.  */

	PTR_S		a0,0(a1)	/* Save function pointer.  */

	PTR_S		a3,PTRSIZE(a1)	/* Save argument pointer.  */

	LONG_S		a2,(PTRSIZE*2)(a1)	/* Save clone flags.  */

	move		a0,a2

	/* Shuffle in the last three arguments - arguments 5, 6, and 7 to

	   this function, but arguments 3, 4, and 5 to the syscall.  */

#if _MIPS_SIM == _ABIO32

	PTR_L		a2,(FRAMESZ+PTRSIZE+PTRSIZE+16)(sp)

	PTR_S		a2,16(sp)

	PTR_L		a2,(FRAMESZ+16)(sp)

	PTR_L		a3,(FRAMESZ+PTRSIZE+16)(sp)

#else

	move		a2,a4

	move		a3,a5

	move		a4,a6

#endif

	/* Do the system call */

	li		v0,__NR_clone

	cfi_endproc

	syscall

	bnez		a3,L(error)

	beqz		v0,L(thread_start)

	/* Successful return from the parent */

	cfi_startproc

	cfi_adjust_cfa_offset (FRAMESZ)

	SETUP_GP64_STACK_CFI (GPOFF)

	cfi_remember_state

	RESTORE_GP64_STACK

	PTR_ADDU	sp, FRAMESZ

	cfi_adjust_cfa_offset (-FRAMESZ)

	ret

	/* Something bad happened -- no child created */

L(error):

	cfi_restore_state

#ifdef __PIC__

	PTR_LA		t9,__syscall_error

	RESTORE_GP64_STACK

	PTR_ADDU	sp, FRAMESZ

	cfi_adjust_cfa_offset (-FRAMESZ)

	jr		t9

#else

	RESTORE_GP64_STACK

	PTR_ADDU	sp, FRAMESZ

	cfi_adjust_cfa_offset (-FRAMESZ)

	j		__syscall_error

#endif

	END(__clone)

/* Load up the arguments to the function.  Put this block of code in

   its own function so that we can terminate the stack trace with our

   debug info.  */

ENTRY(__thread_start)

L(thread_start):

	cfi_undefined ($31)

	/* cp is already loaded.  */

	SAVE_GP (GPOFF)

	/* The stackframe has been created on entry of clone().  */

	/* Restore the arg for user's function.  */

	PTR_L		t9,0(sp)	/* Function pointer.  */

	PTR_L		a0,PTRSIZE(sp)	/* Argument pointer.  */

	/* Call the user's function.  */

	jal		t9

	move		a0,v0

	li		v0,__NR_exit

	syscall

	END(__thread_start)

libc_hidden_def (__clone)

weak_alias (__clone, clone)