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
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
|
/* Set up a context to call a function.
Copyright (C) 2002-2024 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
<https://www.gnu.org/licenses/>. */
#include <sysdep.h>
#include <shlib-compat.h>
#define __ASSEMBLY__
#include <asm/ptrace.h>
#include "ucontext_i.h"
ENTRY(__makecontext)
/* Set up the first 7 args to the function in its registers */
lwz r11,_UC_REGS_PTR(r3)
stw r6,_UC_GREGS+(PT_R3*4)(r11)
stw r7,_UC_GREGS+(PT_R4*4)(r11)
stw r8,_UC_GREGS+(PT_R5*4)(r11)
stw r9,_UC_GREGS+(PT_R6*4)(r11)
stw r10,_UC_GREGS+(PT_R7*4)(r11)
lwz r8,8(r1)
lwz r9,12(r1)
stw r8,_UC_GREGS+(PT_R8*4)(r11)
stw r9,_UC_GREGS+(PT_R9*4)(r11)
/* Set the NIP to the start of the function */
stw r4,_UC_GREGS+(PT_NIP*4)(r11)
/* Set the function's r31 to ucp->uc_link for the exitcode below. */
lwz r7,_UC_LINK(r3)
stw r7,_UC_GREGS+(PT_R31*4)(r11)
/* Set the function's LR to point to the exitcode below. */
#ifdef PIC
mflr r0
cfi_register(lr,r0)
/* Use this conditional form of branch and link to avoid destroying
the cpu link stack used to predict blr return addresses. */
bcl 20,31,1f
1: mflr r6
addi r6,r6,L(exitcode)-1b
mtlr r0
cfi_same_value (lr)
#else
lis r6,L(exitcode)@ha
addi r6,r6,L(exitcode)@l
#endif
stw r6,_UC_GREGS+(PT_LNK*4)(r11)
/*
* Set up the stack frame for the function.
* If we have more than 5 args to the function (8 args to makecontext),
* there will be some arguments on the stack which have to end up
* in registers. If there are more than 8 args to the function,
* we have to copy (argc - 8) args from our stack to the functions'
* stack (and allow space for them in the frame).
*/
lwz r4,_UC_STACK_SP(r3)
lwz r8,_UC_STACK_SIZE(r3)
add r4,r4,r8
rlwinm r4,r4,0,0,27 /* round down to 16-byte boundary */
addi r7,r4,-16 /* stack frame for fn's caller */
cmpwi r5,8
blt 2f /* less than 8 args is easy */
lwz r10,16(r1)
stw r10,_UC_GREGS+(PT_R10*4)(r11)
beq 2f /* if exactly 8 args */
subi r9,r5,3
subi r5,r5,8
rlwinm r9,r9,2,0,27
subf r7,r9,r4
mtctr r5 /* copy the 9th and following args */
addi r6,r1,16
addi r8,r7,4
3: lwzu r10,4(r6)
stwu r10,4(r8)
bdnz 3b
2: stw r7,_UC_GREGS+(PT_R1*4)(r11)
li r6,0
stw r6,0(r7)
blr
cfi_endproc
nop
/*
* If the function returns, it comes here. We put ucp->uc_link in
* r31, which is a callee-saved register. We have to continue with
* the context that r31 points to, or exit if it is 0.
*/
L(exitcode):
mr. r3,r31
beq 4f
bl __setcontext@local
4: bl HIDDEN_JUMPTARGET(exit)
b 4b
cfi_startproc
END(__makecontext)
versioned_symbol (libc, __makecontext, makecontext, GLIBC_2_3_4)
#if SHLIB_COMPAT (libc, GLIBC_2_3_3, GLIBC_2_3_4)
compat_text_section
ENTRY(__novec_makecontext)
/* Set up the first 7 args to the function in its registers */
addi r11,r3,_UC_REG_SPACE
stw r11,_UC_REGS_PTR(r3)
stw r6,_UC_GREGS+(PT_R3*4)(r11)
stw r7,_UC_GREGS+(PT_R4*4)(r11)
stw r8,_UC_GREGS+(PT_R5*4)(r11)
stw r9,_UC_GREGS+(PT_R6*4)(r11)
stw r10,_UC_GREGS+(PT_R7*4)(r11)
lwz r8,8(r1)
lwz r9,12(r1)
stw r8,_UC_GREGS+(PT_R8*4)(r11)
stw r9,_UC_GREGS+(PT_R9*4)(r11)
/* Set the NIP to the start of the function */
stw r4,_UC_GREGS+(PT_NIP*4)(r11)
/* Set the function's r31 to ucp->uc_link for the exitcode below. */
lwz r7,_UC_LINK(r3)
stw r7,_UC_GREGS+(PT_R31*4)(r11)
/* Set the function's LR to point to the exitcode below. */
#ifdef PIC
mflr r0
cfi_register(lr,r0)
/* Use this conditional form of branch and link to avoid destroying
the cpu link stack used to predict blr return addresses. */
bcl 20,31,1f
1: mflr r6
addi r6,r6,L(novec_exitcode)-1b
mtlr r0
cfi_same_value (lr)
#else
lis r6,L(novec_exitcode)@ha
addi r6,r6,L(novec_exitcode)@l
#endif
stw r6,_UC_GREGS+(PT_LNK*4)(r11)
/*
* Set up the stack frame for the function.
* If we have more than 5 args to the function (8 args to makecontext),
* there will be some arguments on the stack which have to end up
* in registers. If there are more than 8 args to the function,
* we have to copy (argc - 8) args from our stack to the functions'
* stack (and allow space for them in the frame).
*/
lwz r4,_UC_STACK_SP(r3)
lwz r8,_UC_STACK_SIZE(r3)
add r4,r4,r8
rlwinm r4,r4,0,0,27 /* round down to 16-byte boundary */
addi r7,r4,-16 /* stack frame for fn's caller */
cmpwi r5,8
blt 2f /* less than 8 args is easy */
lwz r10,16(r1)
stw r10,_UC_GREGS+(PT_R10*4)(r11)
beq 2f /* if exactly 8 args */
subi r9,r5,3
subi r5,r5,8
rlwinm r9,r9,2,0,27
subf r7,r9,r4
mtctr r5 /* copy the 9th and following args */
addi r6,r1,16
addi r8,r7,4
3: lwzu r10,4(r6)
stwu r10,4(r8)
bdnz 3b
2: stw r7,_UC_GREGS+(PT_R1*4)(r11)
li r6,0
stw r6,0(r7)
blr
cfi_endproc
nop
/*
* If the function returns, it comes here. We put ucp->uc_link in
* r31, which is a callee-saved register. We have to continue with
* the context that r31 points to, or exit if it is 0.
*/
L(novec_exitcode):
mr. r3,r31
beq 4f
bl __novec_setcontext@local
4: bl HIDDEN_JUMPTARGET(exit)
b 4b
cfi_startproc
END(__novec_makecontext)
.previous
compat_symbol (libc, __novec_makecontext, makecontext, GLIBC_2_3_3)
#endif
#if SHLIB_COMPAT (libc, GLIBC_2_1, GLIBC_2_3_3)
#define _ERRNO_H 1
#include <bits/errno.h>
compat_text_section
ENTRY (__makecontext_stub)
li r3,ENOSYS
b __syscall_error@local
END (__makecontext_stub)
.previous
compat_symbol (libc, __makecontext_stub, makecontext, GLIBC_2_1)
#endif
|