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
|
/*
* Copyright (C) 2016 Andes Technology, Inc.
* Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
*/
/* 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>
#include <sys/syscall.h>
#define _ERRNO_H 1
#include <bits/errno.h>
/*
int clone(int (*fn)(void *), void *child_stack, int flags, void *arg);
_syscall2(int, clone, int, flags, void *, child_stack)
*/
ENTRY(__clone)
#ifdef PIC
/* set GP register to parent only, cause child's $SP will be $r1. */
pushm $fp, $gp
#ifndef __NDS32_N1213_43U1H__
mfusr $r15, $PC
#endif
sethi $gp, hi20(_GLOBAL_OFFSET_TABLE_+4)
ori $gp, $gp, lo12(_GLOBAL_OFFSET_TABLE_+8)
add $gp, $gp, $r15
#endif
/* sanity check arguments. */
beqz $r0, 1f
bnez $r1, 2f
1:
movi $r0, -EINVAL
5:
#ifdef PIC
/* restore GP register, only in parent's stack */
popm $fp, $gp
la $r15, C_SYMBOL_NAME(__syscall_error@PLT)
jr $r15
#else
b C_SYMBOL_NAME(__syscall_error)
#endif
2:
/* Child's $SP will be $r1, push to child's stack only. */
addi $r1, $r1, -4
swi.p $r3, [$r1], -4 ! arg
swi $r0, [$r1] ! fn
/* do the system call */
or $r0, $r2, $r2 ! move r0, r2
__do_syscall(clone)
!syscall (__NR_clone)
beqz $r0, 4f
bltz $r0, 5b
! parent
#ifdef PIC
/* restore GP register, only in parent's stack */
popm $fp, $gp
#endif
ret
4:
/* Only in child's stack. */
pop $r1 ! fn
pop $r0 ! arg
#if defined(NDS32_ABI_2) || defined(NDS32_ABI_2FP)
#else
addi $sp, $sp, -24
#endif
! use r15 in case _exit is PIC
#ifdef __NDS32_N1213_43U1H__
or $r15, $r1, $r1 ! move r15, r2
#endif
bral $r1
#if defined(NDS32_ABI_2) || defined(NDS32_ABI_2FP)
#else
addi $sp, $sp, 24
#endif
! use r15 in case _exit is PIC
#ifdef PIC
la $r15, C_SYMBOL_NAME(_exit@PLT)
jr $r15
#else
b C_SYMBOL_NAME(_exit)
#endif
PSEUDO_END (__clone)
weak_alias (__clone, clone)
|
