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

/* Copyright (C) 1996, 1997, 2000 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Ralf Baechle <ralf@gnu.ai.mit.edu>, 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, 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 <sys/asm.h>
#include <asm/unistd.h>
#include <sysdep.h>
#define _ERRNO_H	1
#include <bits/errno.h>

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

	.text
NESTED(__clone,4*SZREG,sp)
#ifdef __PIC__
	.set		noreorder
	.cpload		$25
	.set		reorder
	subu		sp,32
	.cprestore	16
#else
	subu		sp,32
#endif
#ifdef PROF
	.set		noat
	move		$1,ra
	jal		_mcount
	.set		at
#endif


	/* Sanity check arguments.  */
	li		v0,EINVAL
	beqz		a0,error	/* No NULL function pointers.  */
	beqz		a1,error	/* No NULL stack pointers.  */

	subu		a1,32		/* Reserve argument save space.  */
	sw		a0,0(a1)	/* Save function pointer.  */
	sw		a3,4(a1)	/* Save argument pointer.  */


	/* Do the system call */
	move		a0,a2
	li		v0,__NR_clone
	syscall

	bnez		a3,error
	beqz		v0,__thread_start

	/* Successful return from the parent */
	addiu		sp,32
	ret

	/* Something bad happened -- no child created */
error:
	addiu		sp,32
#ifdef __PIC__
	la		t9,__syscall_error
	jr		t9
#else
	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)
	/* cp is already loaded.  */
	.cprestore	16
	/* The stackframe has been created on entry of clone().  */
	/* Restore the arg for user's function.  */
	lw		t9,0(sp)	/* Function pointer.  */
	lw		a0,4(sp)	/* Argument pointer.  */

	/* Call the user's function.  */
	jalr		t9

	/* Call _exit rather than doing it inline for breakpoint purposes.  */
	move		a0,v0
#ifdef __PIC__
	la		t9,_exit
	jalr		t9
#else
	jal		_exit
#endif
	END(__thread_start)

weak_alias(__clone, clone)
Commit	Line	Data
69151eeb	1	/* Copyright (C) 1996, 1997, 2000 Free Software Foundation, Inc.
f21acc89 UD	2	This file is part of the GNU C Library.
	3	Contributed by Ralf Baechle <ralf@gnu.ai.mit.edu>, 1996.
	4
	5	The GNU C Library is free software; you can redistribute it and/or
41bdb6e2 AJ	6	modify it under the terms of the GNU Lesser General Public
	7	License as published by the Free Software Foundation; either
	8	version 2.1 of the License, or (at your option) any later version.
f21acc89 UD	9
	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
41bdb6e2	13	Lesser General Public License for more details.
f21acc89	14
41bdb6e2 AJ	15	You should have received a copy of the GNU Lesser General Public
	16	License along with the GNU C Library; if not, write to the Free
	17	Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
	18	02111-1307 USA. */
f21acc89 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 <sys/asm.h>
	24	#include <asm/unistd.h>
	25	#include <sysdep.h>
	26	#define _ERRNO_H 1
	27	#include <bits/errno.h>
	28
44a202c0	29	/* int clone(int (fn)(void arg), void child_stack, int flags, void arg) */
f21acc89 UD	30
f21acc89 UD	31	.text
44a202c0	32	NESTED(__clone,4*SZREG,sp)
69151eeb	33	#ifdef __PIC__
f21acc89 UD	34	.set noreorder
	35	.cpload $25
	36	.set reorder
44a202c0 AJ	37	subu sp,32
44a202c0 AJ	38	.cprestore 16
69151eeb	39	#else
44a202c0	40	subu sp,32
69151eeb	41	#endif
f21acc89 UD	42	#ifdef PROF
	43	.set noat
	44	move $1,ra
	45	jal _mcount
	46	.set at
	47	#endif
	48
44a202c0	49
f21acc89 UD	50	/* Sanity check arguments. */
f21acc89 UD	51	li v0,EINVAL
44a202c0 AJ	52	beqz a0,error /* No NULL function pointers. */
44a202c0 AJ	53	beqz a1,error /* No NULL stack pointers. */
f21acc89	54
44a202c0 AJ	55	subu a1,32 /* Reserve argument save space. */
	56	sw a0,0(a1) /* Save function pointer. */
	57	sw a3,4(a1) /* Save argument pointer. */
69151eeb	58
f21acc89 UD	59
f21acc89 UD	60	/* Do the system call */
f21acc89 UD	61	move a0,a2
	62	li v0,__NR_clone
	63	syscall
	64
	65	bnez a3,error
	66	beqz v0,__thread_start
	67
	68	/* Successful return from the parent */
44a202c0	69	addiu sp,32
f21acc89 UD	70	ret
	71
	72	/* Something bad happened -- no child created */
	73	error:
44a202c0	74	addiu sp,32
b82f6af2	75	#ifdef __PIC__
f21acc89 UD	76	la t9,__syscall_error
	77	jr t9
	78	#else
	79	j __syscall_error
	80	#endif
	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
c45c8be6	85	debug info. */
f21acc89	86
490a9ab7	87	ENTRY(__thread_start)
44a202c0	88	/* cp is already loaded. */
490a9ab7	89	.cprestore 16
69151eeb	90	/* The stackframe has been created on entry of clone(). */
c45c8be6	91	/* Restore the arg for user's function. */
490a9ab7 AJ	92	lw t9,0(sp) /* Function pointer. */
490a9ab7 AJ	93	lw a0,4(sp) /* Argument pointer. */
f21acc89	94
69151eeb	95	/* Call the user's function. */
f21acc89 UD	96	jalr t9
f21acc89 UD	97
69151eeb	98	/* Call _exit rather than doing it inline for breakpoint purposes. */
f21acc89	99	move a0,v0
69151eeb AJ	100	#ifdef __PIC__
	101	la t9,_exit
	102	jalr t9
	103	#else
f21acc89	104	jal _exit
69151eeb	105	#endif
f21acc89 UD	106	END(__thread_start)
	107
	108	weak_alias(__clone, clone)