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
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
|
/* Copyright (C) 1996, 1997, 2000, 2003, 2005 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ralf Baechle <ralf@linux-mips.org>, 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 <sysdep.h>
#define _ERRNO_H 1
#include <bits/errno.h>
#ifdef RESET_PID
#include <tls.h>
#endif
#define CLONE_VM 0x00000100
#define CLONE_THREAD 0x00010000
/* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg,
void *parent_tidptr, void *tls, void *child_tidptr) */
.text
#if _MIPS_SIM == _ABIO32
# define EXTRA_LOCALS 1
#else
# define EXTRA_LOCALS 0
#endif
LOCALSZ= 4
FRAMESZ= (((NARGSAVE+LOCALSZ)*SZREG)+ALSZ)&ALMASK
GPOFF= FRAMESZ-(1*SZREG)
NESTED(__clone,4*SZREG,sp)
#ifdef __PIC__
SETUP_GP
#endif
PTR_SUBU sp, FRAMESZ
SETUP_GP64 (GPOFF, __clone)
#ifdef __PIC__
SAVE_GP (GPOFF)
#endif
#ifdef PROF
.set noat
move $1,ra
jal _mcount
.set at
#endif
/* Sanity check arguments. */
li v0,EINVAL
beqz a0,L(error) /* No NULL function pointers. */
beqz a1,L(error) /* No NULL stack pointers. */
PTR_SUBU a1,32 /* Reserve argument save space. */
PTR_S a0,0(a1) /* Save function pointer. */
PTR_S a3,PTRSIZE(a1) /* Save argument pointer. */
#ifdef RESET_PID
LONG_S a2,(PTRSIZE*2)(a1) /* Save clone flags. */
#endif
move a0,a2
/* Shuffle in the last three arguments - arguments 5, 6, and 7 to
this function, but arguments 3, 4, and 5 to the syscall. */
#if _MIPS_SIM == _ABIO32
PTR_L a2,(FRAMESZ+PTRSIZE+PTRSIZE+16)(sp)
PTR_S a2,16(sp)
PTR_L a2,(FRAMESZ+16)(sp)
PTR_L a3,(FRAMESZ+PTRSIZE+16)(sp)
#else
move a2,a4
move a3,a5
move a4,a6
#endif
/* Do the system call */
li v0,__NR_clone
syscall
bnez a3,L(error)
beqz v0,L(thread_start)
/* Successful return from the parent */
RESTORE_GP64
PTR_ADDU sp, FRAMESZ
ret
/* Something bad happened -- no child created */
L(error):
#ifdef __PIC__
PTR_LA t9,__syscall_error
RESTORE_GP64
PTR_ADDU sp, FRAMESZ
jr t9
#else
RESTORE_GP64
PTR_ADDU sp, FRAMESZ
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)
L(thread_start):
/* cp is already loaded. */
SAVE_GP (GPOFF)
/* The stackframe has been created on entry of clone(). */
#ifdef RESET_PID
/* Check and see if we need to reset the PID. */
LONG_L a0,(PTRSIZE*2)(sp)
and a1,a0,CLONE_THREAD
beqz a1,L(restore_pid)
L(donepid):
#endif
/* Restore the arg for user's function. */
PTR_L t9,0(sp) /* Function pointer. */
PTR_L a0,PTRSIZE(sp) /* Argument pointer. */
/* Call the user's function. */
jal t9
/* Call _exit rather than doing it inline for breakpoint purposes. */
move a0,v0
#ifdef __PIC__
PTR_LA t9,_exit
jalr t9
#else
jal _exit
#endif
#ifdef RESET_PID
L(restore_pid):
and a1,a0,CLONE_VM
li v0,-1
bnez a1,L(gotpid)
li v0,__NR_getpid
syscall
L(gotpid):
READ_THREAD_POINTER(v1)
INT_S v0,PID_OFFSET(v1)
INT_S v0,TID_OFFSET(v1)
b L(donepid)
#endif
END(__thread_start)
weak_alias (__clone, clone)
|
