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
|
/* Set current context.
Copyright (C) 2009-2019 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/>. */
#include "ucontext-macros.h"
/* int __setcontext (const ucontext_t *ucp)
Restores the machine context in UCP and thereby resumes execution
in that context.
This implementation is intended to be used for *synchronous* context
switches only. Therefore, it does not have to restore anything
other than the PRESERVED state. */
.text
LEAF (__setcontext)
mv t0, a0 /* Save ucp into t0. */
/* rt_sigprocmask (SIG_SETMASK, &ucp->uc_sigmask, NULL, _NSIG8) */
li a3, _NSIG8
mv a2, zero
add a1, a0, UCONTEXT_SIGMASK
li a0, SIG_SETMASK
li a7, SYS_ify (rt_sigprocmask)
scall
bltz a0, 99f
cfi_def_cfa (t0, 0)
#ifndef __riscv_float_abi_soft
lw t1, MCONTEXT_FSR(t0)
RESTORE_FP_REG_CFI (fs0, 8, t0)
RESTORE_FP_REG_CFI (fs1, 9, t0)
RESTORE_FP_REG_CFI (fs2, 18, t0)
RESTORE_FP_REG_CFI (fs3, 19, t0)
RESTORE_FP_REG_CFI (fs4, 20, t0)
RESTORE_FP_REG_CFI (fs5, 21, t0)
RESTORE_FP_REG_CFI (fs6, 22, t0)
RESTORE_FP_REG_CFI (fs7, 23, t0)
RESTORE_FP_REG_CFI (fs8, 24, t0)
RESTORE_FP_REG_CFI (fs9, 25, t0)
RESTORE_FP_REG_CFI (fs10, 26, t0)
RESTORE_FP_REG_CFI (fs11, 27, t0)
fssr t1
#endif /* __riscv_float_abi_soft */
/* Note the contents of argument registers will be random
unless makecontext() has been called. */
RESTORE_INT_REG (t1, 0, t0)
RESTORE_INT_REG_CFI (ra, 1, t0)
RESTORE_INT_REG (sp, 2, t0)
RESTORE_INT_REG_CFI (s0, 8, t0)
RESTORE_INT_REG_CFI (s1, 9, t0)
RESTORE_INT_REG (a0, 10, t0)
RESTORE_INT_REG (a1, 11, t0)
RESTORE_INT_REG (a2, 12, t0)
RESTORE_INT_REG (a3, 13, t0)
RESTORE_INT_REG (a4, 14, t0)
RESTORE_INT_REG (a5, 15, t0)
RESTORE_INT_REG (a6, 16, t0)
RESTORE_INT_REG (a7, 17, t0)
RESTORE_INT_REG_CFI (s2, 18, t0)
RESTORE_INT_REG_CFI (s3, 19, t0)
RESTORE_INT_REG_CFI (s4, 20, t0)
RESTORE_INT_REG_CFI (s5, 21, t0)
RESTORE_INT_REG_CFI (s6, 22, t0)
RESTORE_INT_REG_CFI (s7, 23, t0)
RESTORE_INT_REG_CFI (s8, 24, t0)
RESTORE_INT_REG_CFI (s9, 25, t0)
RESTORE_INT_REG_CFI (s10, 26, t0)
RESTORE_INT_REG_CFI (s11, 27, t0)
jr t1
99: j __syscall_error
END (__setcontext)
weak_alias (__setcontext, setcontext)
LEAF (__start_context)
/* Terminate call stack by noting ra == 0. Happily, s0 == 0 here. */
cfi_register (ra, s0)
/* Call the function passed to makecontext. */
jalr s1
/* Invoke subsequent context if present, else exit(0). */
mv a0, s2
beqz s2, 1f
jal __setcontext
1: j exit
END (__start_context)
|
