/* Wrapper around clone system call.  PowerPC64 version.

   Copyright (C) 1997-2018 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/>.  */

#include <sysdep.h>

#define _ERRNO_H	1

#include <bits/errno.h>

/* This is the only really unusual system call in PPC linux, but not

   because of any weirdness in the system call itself; because of

   all the freaky stuff we have to do to make the call useful.  */

/* int [r3] clone(int (*fn)(void *arg) [r3], void *child_stack [r4],

                  int flags [r5], void *arg [r6], void *parent_tid [r7],

                  void *tls [r8], void *child_tid [r9]); */

ENTRY (__clone)

	CALL_MCOUNT 7

	/* Check for child_stack == NULL || fn == NULL.  */

	cmpdi	cr0,r4,0

	cmpdi	cr1,r3,0

	cror	cr0*4+eq,cr1*4+eq,cr0*4+eq

	beq-	cr0,L(badargs)

	/* Save some regs in the "red zone".  */

	std	r29,-24(r1)

	std	r30,-16(r1)

	std	r31,-8(r1)

	cfi_offset(r29,-24)

	cfi_offset(r30,-16)

	cfi_offset(r31,-8)

	/* Set up stack frame for child.  */

	clrrdi	r4,r4,4

	li	r0,0

	stdu	r0,-FRAME_MIN_SIZE_PARM(r4)

	/* Save fn, args, stack across syscall.  */

	mr	r30,r3			/* Function in r30.  */

	mr	r29,r5			/* Flags in r29.  */

	mr	r31,r6			/* Argument in r31.  */

	/* 'flags' argument is first parameter to clone syscall.

	   Second is the stack pointer, already in r4.  */

	mr	r3,r5

	/* Move the parent_tid, child_tid and tls arguments. */

	mr	r5,r7

	mr	r6,r8

	mr	r7,r9

	/* End FDE now, because in the child the unwind info will be

	   wrong.  */

	cfi_endproc

	/* Do the call.  */

	DO_CALL(SYS_ify(clone))

	/* Check for child process.  */

	cmpdi	cr1,r3,0

	crandc	cr1*4+eq,cr1*4+eq,cr0*4+so

	bne-	cr1,L(parent)		/* The '-' is to minimise the race.  */

	std	r2,FRAME_TOC_SAVE(r1)

	/* Call procedure.  */

	PPC64_LOAD_FUNCPTR r30

	mr	r3,r31

	bctrl

	ld	r2,FRAME_TOC_SAVE(r1)

	DO_CALL(SYS_ify(exit))

	/* We won't ever get here but provide a nop so that the linker

	   will insert a toc adjusting stub if necessary.  */

	nop

L(badargs):

	cfi_startproc

	li	r3,EINVAL

	TAIL_CALL_SYSCALL_ERROR

L(parent):

	/* Parent.  Restore registers & return.  */

	cfi_offset(r29,-24)

	cfi_offset(r30,-16)

	cfi_offset(r31,-8)

	ld	r29,-24(r1)

	ld	r30,-16(r1)

	ld	r31,-8(r1)

	cfi_restore(r29)

	cfi_restore(r30)

	cfi_restore(r31)

	PSEUDO_RET

END (__clone)

libc_hidden_def (__clone)

weak_alias (__clone, clone)