1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
|
/* Copyright (C) 2005 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, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
/* vfork() is just a special case of clone(). */
#include <sys/asm.h>
#include <sysdep.h>
#include <sgidefs.h>
#ifdef __PTHREADS_NATIVE__
#include <tls.h>
/* Save the PID value. */
#ifndef SAVE_PID
#define SAVE_PID \
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. */
#endif
/* Restore the old PID value in the parent. */
#ifndef RESTORE_PID
#define RESTORE_PID \
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:
#endif
#endif
#ifndef SAVE_PID
#define SAVE_PID
#endif
#ifndef RESTORE_PID
#define RESTORE_PID
#endif
/* int vfork() */
.text
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
SETUP_GP64 (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
SAVE_PID
li a0, 0x4112 /* CLONE_VM | CLONE_VFORK | SIGCHLD */
move a1, sp
/* Do the system call */
li v0,__NR_clone
syscall
RESTORE_PID
bnez a3,L(error)
/* Successful return from the parent or child. */
RESTORE_GP64
j ra
nop
/* Something bad happened -- no child created. */
L(error):
#ifdef __PIC__
PTR_LA t9, __syscall_error
RESTORE_GP64
jr t9
#else
RESTORE_GP64
j __syscall_error
#endif
END(__vfork)
.weak vfork;
vfork = __vfork
|
