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
|
/*
* Copyright (C) 2016 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <stdint.h>
#include <string.h>
#include <functional>
#include <unwindstack/Elf.h>
#include <unwindstack/MachineArm.h>
#include <unwindstack/MapInfo.h>
#include <unwindstack/Memory.h>
#include <unwindstack/RegsArm.h>
#include <unwindstack/UcontextArm.h>
#include <unwindstack/UserArm.h>
namespace unwindstack {
RegsArm::RegsArm() : RegsImpl<uint32_t>(ARM_REG_LAST, Location(LOCATION_REGISTER, ARM_REG_LR)) {}
ArchEnum RegsArm::Arch() {
return ARCH_ARM;
}
uint64_t RegsArm::pc() {
return regs_[ARM_REG_PC];
}
uint64_t RegsArm::sp() {
return regs_[ARM_REG_SP];
}
void RegsArm::set_pc(uint64_t pc) {
regs_[ARM_REG_PC] = pc;
}
void RegsArm::set_sp(uint64_t sp) {
regs_[ARM_REG_SP] = sp;
}
uint64_t RegsArm::GetPcAdjustment(uint64_t rel_pc, Elf* elf) {
if (!elf->valid()) {
return 2;
}
uint64_t load_bias = elf->GetLoadBias();
if (rel_pc < load_bias) {
if (rel_pc < 2) {
return 0;
}
return 2;
}
uint64_t adjusted_rel_pc = rel_pc - load_bias;
if (adjusted_rel_pc < 5) {
if (adjusted_rel_pc < 2) {
return 0;
}
return 2;
}
if (adjusted_rel_pc & 1) {
// This is a thumb instruction, it could be 2 or 4 bytes.
uint32_t value;
if (!elf->memory()->ReadFully(adjusted_rel_pc - 5, &value, sizeof(value)) ||
(value & 0xe000f000) != 0xe000f000) {
return 2;
}
}
return 4;
}
bool RegsArm::SetPcFromReturnAddress(Memory*) {
uint32_t lr = regs_[ARM_REG_LR];
if (regs_[ARM_REG_PC] == lr) {
return false;
}
regs_[ARM_REG_PC] = lr;
return true;
}
void RegsArm::IterateRegisters(std::function<void(const char*, uint64_t)> fn) {
fn("r0", regs_[ARM_REG_R0]);
fn("r1", regs_[ARM_REG_R1]);
fn("r2", regs_[ARM_REG_R2]);
fn("r3", regs_[ARM_REG_R3]);
fn("r4", regs_[ARM_REG_R4]);
fn("r5", regs_[ARM_REG_R5]);
fn("r6", regs_[ARM_REG_R6]);
fn("r7", regs_[ARM_REG_R7]);
fn("r8", regs_[ARM_REG_R8]);
fn("r9", regs_[ARM_REG_R9]);
fn("r10", regs_[ARM_REG_R10]);
fn("r11", regs_[ARM_REG_R11]);
fn("ip", regs_[ARM_REG_R12]);
fn("sp", regs_[ARM_REG_SP]);
fn("lr", regs_[ARM_REG_LR]);
fn("pc", regs_[ARM_REG_PC]);
}
Regs* RegsArm::Read(void* remote_data) {
arm_user_regs* user = reinterpret_cast<arm_user_regs*>(remote_data);
RegsArm* regs = new RegsArm();
memcpy(regs->RawData(), &user->regs[0], ARM_REG_LAST * sizeof(uint32_t));
return regs;
}
Regs* RegsArm::CreateFromUcontext(void* ucontext) {
arm_ucontext_t* arm_ucontext = reinterpret_cast<arm_ucontext_t*>(ucontext);
RegsArm* regs = new RegsArm();
memcpy(regs->RawData(), &arm_ucontext->uc_mcontext.regs[0], ARM_REG_LAST * sizeof(uint32_t));
return regs;
}
bool RegsArm::StepIfSignalHandler(uint64_t rel_pc, Elf* elf, Memory* process_memory) {
uint32_t data;
Memory* elf_memory = elf->memory();
// Read from elf memory since it is usually more expensive to read from
// process memory.
if (!elf_memory->ReadFully(rel_pc, &data, sizeof(data))) {
return false;
}
uint64_t offset = 0;
if (data == 0xe3a07077 || data == 0xef900077 || data == 0xdf002777) {
uint64_t sp = regs_[ARM_REG_SP];
// non-RT sigreturn call.
// __restore:
//
// Form 1 (arm):
// 0x77 0x70 mov r7, #0x77
// 0xa0 0xe3 svc 0x00000000
//
// Form 2 (arm):
// 0x77 0x00 0x90 0xef svc 0x00900077
//
// Form 3 (thumb):
// 0x77 0x27 movs r7, #77
// 0x00 0xdf svc 0
if (!process_memory->ReadFully(sp, &data, sizeof(data))) {
return false;
}
if (data == 0x5ac3c35a) {
// SP + uc_mcontext offset + r0 offset.
offset = sp + 0x14 + 0xc;
} else {
// SP + r0 offset
offset = sp + 0xc;
}
} else if (data == 0xe3a070ad || data == 0xef9000ad || data == 0xdf0027ad) {
uint64_t sp = regs_[ARM_REG_SP];
// RT sigreturn call.
// __restore_rt:
//
// Form 1 (arm):
// 0xad 0x70 mov r7, #0xad
// 0xa0 0xe3 svc 0x00000000
//
// Form 2 (arm):
// 0xad 0x00 0x90 0xef svc 0x009000ad
//
// Form 3 (thumb):
// 0xad 0x27 movs r7, #ad
// 0x00 0xdf svc 0
if (!process_memory->ReadFully(sp, &data, sizeof(data))) {
return false;
}
if (data == sp + 8) {
// SP + 8 + sizeof(siginfo_t) + uc_mcontext_offset + r0 offset
offset = sp + 8 + 0x80 + 0x14 + 0xc;
} else {
// SP + sizeof(siginfo_t) + uc_mcontext_offset + r0 offset
offset = sp + 0x80 + 0x14 + 0xc;
}
}
if (offset == 0) {
return false;
}
if (!process_memory->ReadFully(offset, regs_.data(), sizeof(uint32_t) * ARM_REG_LAST)) {
return false;
}
return true;
}
Regs* RegsArm::Clone() {
return new RegsArm(*this);
}
} // namespace unwindstack
|
