[thirdparty/glibc.git] / sysdeps / unix / sysv / linux / alpha / clone.S

/* Copyright (C) 1996 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Richard Henderson <rth@tamu.edu>, 1996.

   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 <sysdep.h>
#define _ERRNO_H	1
#include <errnos.h>

/* int clone(int (*fn)(), void *child_stack, int flags, int nargs, ...) */

        .text
ENTRY(__clone)
	lda	sp,-16(sp)
	.frame	sp,16,$26,0
	/* Save rest of argument registers for varargs-type work.  */
	stq	a4,0(sp)
	stq	a5,8(sp)
#ifdef PROF
	.set noat
	lda	AT, _mcount
	jsr	AT, (AT), _mcount
	.set at
#endif
	.prologue 1

	/* Sanity check arguments.  */
	sextl	a3,a3
	ldiq	v0,EINVAL
	beq	a0,$error		/* no NULL function pointers */
	beq	a1,$error		/* no NULL stack pointers */
	blt	a3,$error		/* no negative argument counts */

	/* Allocate space on the new stack and copy args over */
	mov	a3,t0			/* save nargs for thread_start */
	s8addq	a3,sp,t1
1:	ldq	t2,-8(t1)
	subq	t1,8,t1
	stq	t2,-8(a1)
	subq	a3,1,a3
	subq	a1,8,a1
	bne	a3,1b

	/* Do the system call */
	mov	a0,pv			/* get fn ptr out of the way */
	mov	a2,a0
	ldiq	v0,__NR_clone
	call_pal PAL_callsys

	bne	a3,$error
	beq	v0,thread_start

	/* Successful return from the parent */
	lda	sp,16(sp)
	ret

	/* Something bad happened -- no child created */
$error:
	br	gp,1f
1:	ldgp	gp,0(gp)
	lda	sp,16(sp)
	jmp	zero,__syscall_error

	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.

   At this point we have $t0=nargs, $pv=fn, $sp=&arg[0].  */

	.ent thread_start
thread_start:
	.frame fp,0,zero,0
	mov	zero,fp
	.prologue 0

	/* Calculate address of jump into argument loading code */
	cmple	t0,6,t2		/* no more than 6 args in registers */
	cmoveq	t2,6,t0
	br	v0,1f		/* find address of arg0 */
1:	lda	v0,$arg0-1b(v0)
	s4addq	t0,zero,t1
	subq	v0,t1,v0
	jmp	(v0)

	/* Load the integer register arguments */
	ldq	a5,40(sp)
	ldq	a4,32(sp)
	ldq	a3,24(sp)
	ldq	a2,16(sp)
	ldq	a1,8(sp)
	ldq	a0,0(sp)
$arg0:

	/* Adjust stack to remove the arguments we just loaded */
	s8addq	t0,sp,sp

	/* Call the user's function */
	jsr	ra,(pv)
	ldgp	gp,0(ra)

	/* Call _exit rather than doing it inline for breakpoint purposes */
	mov	v0,a0
	jsr	ra,_exit

	.end thread_start

weak_alias(__clone, clone)
Commit	Line	Data
3b0174d0	1	/* Copyright (C) 1996 Free Software Foundation, Inc.
3c7b2587 UD	2	This file is part of the GNU C Library.
3c7b2587 UD	3	Contributed by Richard Henderson <rth@tamu.edu>, 1996.
3b0174d0	4
3c7b2587 UD	5	The GNU C Library is free software; you can redistribute it and/or
	6	modify it under the terms of the GNU Library General Public License as
	7	published by the Free Software Foundation; either version 2 of the
	8	License, or (at your option) any later version.
3b0174d0	9
3c7b2587 UD	10	The GNU C Library is distributed in the hope that it will be useful,
	11	but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	13	Library General Public License for more details.
3b0174d0	14
3c7b2587 UD	15	You should have received a copy of the GNU Library General Public
	16	License along with the GNU C Library; see the file COPYING.LIB. If not,
	17	write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
	18	Boston, MA 02111-1307, USA. */
3b0174d0 UD	19
	20	/* clone() is even more special than fork() as it mucks with stacks
	21	and invokes a function in the right context after its all over. */
	22
	23	#include <sysdep.h>
81e25b60	24	#define _ERRNO_H 1
3b0174d0 UD	25	#include <errnos.h>
	26
	27	/* int clone(int (fn)(), void child_stack, int flags, int nargs, ...) */
	28
	29	.text
	30	ENTRY(__clone)
	31	lda sp,-16(sp)
	32	.frame sp,16,$26,0
	33	/* Save rest of argument registers for varargs-type work. */
	34	stq a4,0(sp)
	35	stq a5,8(sp)
dd4b8913	36	#ifdef PROF
3c7b2587	37	.set noat
dd4b8913 UD	38	lda AT, _mcount
dd4b8913 UD	39	jsr AT, (AT), _mcount
3c7b2587	40	.set at
dd4b8913	41	#endif
3b0174d0 UD	42	.prologue 1
	43
	44	/* Sanity check arguments. */
	45	sextl a3,a3
	46	ldiq v0,EINVAL
	47	beq a0,$error /* no NULL function pointers */
	48	beq a1,$error /* no NULL stack pointers */
	49	blt a3,$error /* no negative argument counts */
	50
	51	/* Allocate space on the new stack and copy args over */
	52	mov a3,t0 /* save nargs for thread_start */
	53	s8addq a3,sp,t1
	54	1: ldq t2,-8(t1)
	55	subq t1,8,t1
	56	stq t2,-8(a1)
	57	subq a3,1,a3
	58	subq a1,8,a1
	59	bne a3,1b
	60
	61	/* Do the system call */
	62	mov a0,pv /* get fn ptr out of the way */
	63	mov a2,a0
	64	ldiq v0,__NR_clone
	65	call_pal PAL_callsys
	66
	67	bne a3,$error
	68	beq v0,thread_start
	69
	70	/* Successful return from the parent */
	71	lda sp,16(sp)
	72	ret
	73
	74	/* Something bad happened -- no child created */
	75	$error:
	76	br gp,1f
	77	1: ldgp gp,0(gp)
	78	lda sp,16(sp)
	79	jmp zero,__syscall_error
	80
	81	END(__clone)
	82
	83	/* Load up the arguments to the function. Put this block of code in
	84	its own function so that we can terminate the stack trace with our
	85	debug info.
	86
	87	At this point we have $t0=nargs, $pv=fn, $sp=&arg[0]. */
	88
	89	.ent thread_start
	90	thread_start:
	91	.frame fp,0,zero,0
	92	mov zero,fp
	93	.prologue 0
	94
	95	/* Calculate address of jump into argument loading code */
	96	cmple t0,6,t2 /* no more than 6 args in registers */
	97	cmoveq t2,6,t0
	98	br v0,1f /* find address of arg0 */
	99	1: lda v0,$arg0-1b(v0)
	100	s4addq t0,zero,t1
	101	subq v0,t1,v0
	102	jmp (v0)
	103
	104	/* Load the integer register arguments */
	105	ldq a5,40(sp)
106	ldq a4,32(sp)
107	ldq a3,24(sp)
108	ldq a2,16(sp)
109	ldq a1,8(sp)
110	ldq a0,0(sp)
111	$arg0:
112
113	/* Adjust stack to remove the arguments we just loaded */
114	s8addq t0,sp,sp
115
116	/* Call the user's function */
117	jsr ra,(pv)
118	ldgp gp,0(ra)
119
120	/* Call _exit rather than doing it inline for breakpoint purposes */
121	mov v0,a0
122	jsr ra,_exit
123
124	.end thread_start
125
126	weak_alias(__clone, clone)