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
227
228
229
230
231
232
233
234
235
236
237
|
/*
* Copyright (C) 2017 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 <errno.h>
#include <string.h>
#include <signal.h>
#include <stdint.h>
#include <sys/ptrace.h>
#include <sys/syscall.h>
#include <unistd.h>
#include <gtest/gtest.h>
#include <atomic>
#include <memory>
#include <sstream>
#include <string>
#include <thread>
#include <unwindstack/Elf.h>
#include <unwindstack/MapInfo.h>
#include <unwindstack/Maps.h>
#include <unwindstack/Memory.h>
#include <unwindstack/Regs.h>
#include <unwindstack/RegsGetLocal.h>
namespace unwindstack {
static std::atomic_bool g_ready(false);
static volatile bool g_ready_for_remote = false;
static std::atomic_bool g_finish(false);
static std::atomic_uintptr_t g_ucontext;
static void Signal(int, siginfo_t*, void* sigcontext) {
g_ucontext = reinterpret_cast<uintptr_t>(sigcontext);
while (!g_finish.load()) {
}
}
static std::string ErrorMsg(const char** function_names, size_t index,
std::stringstream& unwind_stream) {
return std::string(
"Unwind completed without finding all frames\n"
" Looking for function: ") +
function_names[index] + "\n" + "Unwind data:\n" + unwind_stream.str();
}
static void VerifyUnwind(pid_t pid, Memory* memory, Maps* maps, Regs* regs) {
const char* function_names[] = {
"InnerFunction", "MiddleFunction", "OuterFunction",
};
size_t function_name_index = 0;
std::stringstream unwind_stream;
unwind_stream << std::hex;
for (size_t frame_num = 0; frame_num < 64; frame_num++) {
ASSERT_NE(0U, regs->pc()) << ErrorMsg(function_names, function_name_index, unwind_stream);
MapInfo* map_info = maps->Find(regs->pc());
ASSERT_TRUE(map_info != nullptr) << ErrorMsg(function_names, function_name_index, unwind_stream);
Elf* elf = map_info->GetElf(pid, true);
uint64_t rel_pc = elf->GetRelPc(regs->pc(), map_info);
uint64_t adjusted_rel_pc = rel_pc;
if (frame_num != 0) {
adjusted_rel_pc = regs->GetAdjustedPc(rel_pc, elf);
}
unwind_stream << " PC: 0x" << regs->pc() << " Rel: 0x" << adjusted_rel_pc;
unwind_stream << " Map: ";
if (!map_info->name.empty()) {
unwind_stream << map_info->name;
} else {
unwind_stream << " anonymous";
}
unwind_stream << "<" << map_info->start << "-" << map_info->end << ">";
std::string name;
uint64_t func_offset;
if (elf->GetFunctionName(adjusted_rel_pc, &name, &func_offset)) {
if (name == function_names[function_name_index]) {
function_name_index++;
if (function_name_index == sizeof(function_names) / sizeof(const char*)) {
return;
}
}
unwind_stream << " " << name;
}
unwind_stream << "\n";
ASSERT_TRUE(elf->Step(rel_pc + map_info->elf_offset, regs, memory))
<< ErrorMsg(function_names, function_name_index, unwind_stream);
}
ASSERT_TRUE(false) << ErrorMsg(function_names, function_name_index, unwind_stream);
}
// This test assumes that this code is compiled with optimizations turned
// off. If this doesn't happen, then all of the calls will be optimized
// away.
extern "C" void InnerFunction(bool local) {
if (local) {
LocalMaps maps;
ASSERT_TRUE(maps.Parse());
std::unique_ptr<Regs> regs(Regs::CreateFromLocal());
RegsGetLocal(regs.get());
MemoryLocal memory;
VerifyUnwind(getpid(), &memory, &maps, regs.get());
} else {
g_ready_for_remote = true;
g_ready = true;
while (!g_finish.load()) {
}
}
}
extern "C" void MiddleFunction(bool local) {
InnerFunction(local);
}
extern "C" void OuterFunction(bool local) {
MiddleFunction(local);
}
TEST(UnwindTest, local) {
OuterFunction(true);
}
TEST(UnwindTest, remote) {
pid_t pid;
if ((pid = fork()) == 0) {
OuterFunction(false);
exit(0);
}
ASSERT_NE(-1, pid);
bool ready = false;
uint64_t addr = reinterpret_cast<uint64_t>(&g_ready_for_remote);
for (size_t i = 0; i < 100; i++) {
ASSERT_EQ(0, ptrace(PTRACE_ATTACH, pid, 0, 0));
for (size_t j = 0; j < 100; j++) {
siginfo_t si;
if (ptrace(PTRACE_GETSIGINFO, pid, 0, &si) == 0) {
// Check to see if process is ready to be unwound.
MemoryRemote memory(pid);
// Read the remote value to see if we are ready.
bool value;
if (memory.Read(addr, &value, sizeof(value)) && value) {
ready = true;
break;
}
}
usleep(1000);
}
if (ready) {
break;
}
ASSERT_EQ(0, ptrace(PTRACE_DETACH, pid, 0, 0));
usleep(1000);
}
ASSERT_TRUE(read) << "Timed out waiting for remote process to be ready.";
RemoteMaps maps(pid);
ASSERT_TRUE(maps.Parse());
MemoryRemote memory(pid);
uint32_t machine_type;
std::unique_ptr<Regs> regs(Regs::RemoteGet(pid, &machine_type));
ASSERT_TRUE(regs.get() != nullptr);
VerifyUnwind(pid, &memory, &maps, regs.get());
ASSERT_EQ(0, ptrace(PTRACE_DETACH, pid, 0, 0));
kill(pid, SIGKILL);
ASSERT_EQ(pid, wait(nullptr));
}
TEST(UnwindTest, from_context) {
std::atomic_int tid(0);
std::thread thread([&]() {
tid = syscall(__NR_gettid);
OuterFunction(false);
});
struct sigaction act, oldact;
memset(&act, 0, sizeof(act));
act.sa_sigaction = Signal;
act.sa_flags = SA_RESTART | SA_SIGINFO | SA_ONSTACK;
ASSERT_EQ(0, sigaction(SIGUSR1, &act, &oldact));
// Wait for the tid to get set.
for (size_t i = 0; i < 100; i++) {
if (tid.load() != 0) {
break;
}
usleep(1000);
}
ASSERT_NE(0, tid.load());
// Portable tgkill method.
ASSERT_EQ(0, syscall(__NR_tgkill, getpid(), tid.load(), SIGUSR1)) << "Failed because "
<< strerror(errno);
// Wait for context data.
void* ucontext;
for (size_t i = 0; i < 2000; i++) {
ucontext = reinterpret_cast<void*>(g_ucontext.load());
if (ucontext != nullptr) {
break;
}
usleep(1000);
}
ASSERT_TRUE(ucontext != nullptr) << "Timed out waiting for thread to respond to signal.";
LocalMaps maps;
ASSERT_TRUE(maps.Parse());
std::unique_ptr<Regs> regs(Regs::CreateFromUcontext(Regs::GetMachineType(), ucontext));
MemoryLocal memory;
VerifyUnwind(tid.load(), &memory, &maps, regs.get());
ASSERT_EQ(0, sigaction(SIGUSR1, &oldact, nullptr));
g_finish = true;
thread.join();
}
} // namespace unwindstack
|
