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

/* Copyright (C) 2005-2016 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/>.  */

/* vfork() is just a special case of clone().  */

#include <sys/asm.h>
#include <sysdep.h>
#include <asm/unistd.h>
#include <sgidefs.h>
#include <tls.h>


/* int vfork() */

	.text
	.set		nomips16
LOCALSZ= 1
FRAMESZ= (((NARGSAVE+LOCALSZ)*SZREG)+ALSZ)&ALMASK
GPOFF= FRAMESZ-(1*SZREG)
NESTED(__vfork,FRAMESZ,sp)
#ifdef __PIC__
	SETUP_GP
#endif
	PTR_SUBU sp, FRAMESZ
	cfi_adjust_cfa_offset (FRAMESZ)
	SETUP_GP64_REG (a5, __vfork)
#ifdef __PIC__
	SAVE_GP (GPOFF)
#endif
#ifdef PROF
# if (_MIPS_SIM != _ABIO32)
	PTR_S		a5, GPOFF(sp)
# endif
	.set		noat
	move		$1, ra
# if (_MIPS_SIM == _ABIO32)
	subu		sp,sp,8
# endif
	jal		_mcount
	.set		at
# if (_MIPS_SIM != _ABIO32)
	PTR_L		a5, GPOFF(sp)
# endif
#endif

	PTR_ADDU	sp, FRAMESZ
	cfi_adjust_cfa_offset (-FRAMESZ)

	/* Save the PID value.  */
	READ_THREAD_POINTER(v1)	   /* Get the thread pointer.  */
	lw	a2, PID_OFFSET(v1) /* Load the saved PID.  */
	subu	a2, $0, a2	   /* Negate it.  */
	bnez	a2, 1f		   /* If it was zero... */
	lui	a2, 0x8000	   /* use 0x80000000 instead.  */
1:	sw	a2, PID_OFFSET(v1) /* Store the temporary PID.  */

	li		a0, 0x4112	/* CLONE_VM | CLONE_VFORK | SIGCHLD */
	move		a1, sp

	/* Do the system call */
	li		v0,__NR_clone
	syscall

	/* Restore the old PID value in the parent.  */
	beqz	v0, 1f		/* If we are the parent... */
	READ_THREAD_POINTER(v1)	/* Get the thread pointer.  */
	lw	a2, PID_OFFSET(v1) /* Load the saved PID.  */
	subu	a2, $0, a2	   /* Re-negate it.  */
	lui	a0, 0x8000	   /* Load 0x80000000... */
	bne	a2, a0, 2f	   /* ... compare against it... */
	li	a2, 0		   /* ... use 0 instead.  */
2:	sw	a2, PID_OFFSET(v1) /* Restore the PID.  */
1:

	cfi_remember_state
	bnez		a3,L(error)

	/* Successful return from the parent or child.  */
	RESTORE_GP64_REG
	ret

	/* Something bad happened -- no child created.  */
L(error):
	cfi_restore_state
#ifdef __PIC__
	PTR_LA		t9, __syscall_error
	RESTORE_GP64_REG
	jr		t9
#else
	RESTORE_GP64_REG
	j		__syscall_error
#endif
	END(__vfork)

libc_hidden_def(__vfork)
weak_alias (__vfork, vfork)
strong_alias (__vfork, __libc_vfork)
Commit	Line	Data
f7a9f785	1	/* Copyright (C) 2005-2016 Free Software Foundation, Inc.
4abf7dea AJ	2	This file is part of the GNU C Library.
	3
	4	The GNU C Library is free software; you can redistribute it and/or
	5	modify it under the terms of the GNU Lesser General Public
	6	License as published by the Free Software Foundation; either
	7	version 2.1 of the License, or (at your option) any later version.
	8
	9	The GNU C Library is distributed in the hope that it will be useful,
	10	but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	12	Lesser General Public License for more details.
	13
	14	You should have received a copy of the GNU Lesser General Public
ab84e3ff PE	15	License along with the GNU C Library. If not, see
ab84e3ff PE	16	<http://www.gnu.org/licenses/>. */
4abf7dea AJ	17
	18	/* vfork() is just a special case of clone(). */
	19
	20	#include <sys/asm.h>
	21	#include <sysdep.h>
	22	#include <asm/unistd.h>
	23	#include <sgidefs.h>
58eb0862	24	#include <tls.h>
4abf7dea AJ	25
	26
	27	/* int vfork() */
	28
	29	.text
43301bd3	30	.set nomips16
4abf7dea AJ	31	LOCALSZ= 1
	32	FRAMESZ= (((NARGSAVE+LOCALSZ)*SZREG)+ALSZ)&ALMASK
	33	GPOFF= FRAMESZ-(1*SZREG)
	34	NESTED(__vfork,FRAMESZ,sp)
	35	#ifdef __PIC__
	36	SETUP_GP
	37	#endif
	38	PTR_SUBU sp, FRAMESZ
aea7a9b9 JM	39	cfi_adjust_cfa_offset (FRAMESZ)
aea7a9b9 JM	40	SETUP_GP64_REG (a5, __vfork)
4abf7dea AJ	41	#ifdef __PIC__
	42	SAVE_GP (GPOFF)
	43	#endif
	44	#ifdef PROF
	45	# if (_MIPS_SIM != _ABIO32)
	46	PTR_S a5, GPOFF(sp)
	47	# endif
	48	.set noat
	49	move $1, ra
	50	# if (_MIPS_SIM == _ABIO32)
	51	subu sp,sp,8
	52	# endif
	53	jal _mcount
	54	.set at
	55	# if (_MIPS_SIM != _ABIO32)
	56	PTR_L a5, GPOFF(sp)
	57	# endif
	58	#endif
	59
	60	PTR_ADDU sp, FRAMESZ
aea7a9b9	61	cfi_adjust_cfa_offset (-FRAMESZ)
4abf7dea	62
58eb0862 RM	63	/* Save the PID value. */
	64	READ_THREAD_POINTER(v1) /* Get the thread pointer. */
	65	lw a2, PID_OFFSET(v1) /* Load the saved PID. */
	66	subu a2, $0, a2 /* Negate it. */
	67	bnez a2, 1f /* If it was zero... */
	68	lui a2, 0x8000 /* use 0x80000000 instead. */
	69	1: sw a2, PID_OFFSET(v1) /* Store the temporary PID. */
4abf7dea AJ	70
	71	li a0, 0x4112 /* CLONE_VM \| CLONE_VFORK \| SIGCHLD */
	72	move a1, sp
	73
	74	/* Do the system call */
	75	li v0,__NR_clone
	76	syscall
	77
58eb0862 RM	78	/* Restore the old PID value in the parent. */
	79	beqz v0, 1f /* If we are the parent... */
	80	READ_THREAD_POINTER(v1) /* Get the thread pointer. */
	81	lw a2, PID_OFFSET(v1) /* Load the saved PID. */
	82	subu a2, $0, a2 /* Re-negate it. */
	83	lui a0, 0x8000 /* Load 0x80000000... */
	84	bne a2, a0, 2f /* ... compare against it... */
	85	li a2, 0 /* ... use 0 instead. */
	86	2: sw a2, PID_OFFSET(v1) /* Restore the PID. */
	87	1:
4abf7dea	88
aea7a9b9	89	cfi_remember_state
4abf7dea AJ	90	bnez a3,L(error)
	91
	92	/* Successful return from the parent or child. */
aea7a9b9	93	RESTORE_GP64_REG
4abf7dea AJ	94	ret
	95
	96	/* Something bad happened -- no child created. */
	97	L(error):
aea7a9b9	98	cfi_restore_state
4abf7dea AJ	99	#ifdef __PIC__
4abf7dea AJ	100	PTR_LA t9, __syscall_error
aea7a9b9	101	RESTORE_GP64_REG
4abf7dea AJ	102	jr t9
4abf7dea AJ	103	#else
aea7a9b9	104	RESTORE_GP64_REG
4abf7dea AJ	105	j __syscall_error
	106	#endif
	107	END(__vfork)
	108
	109	libc_hidden_def(__vfork)
8796ce21	110	weak_alias (__vfork, vfork)
b5af9297	111	strong_alias (__vfork, __libc_vfork)