1 /*
2 * Copyright (C) 2016 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include <errno.h>
18 #include <signal.h>
19 #include <stdint.h>
20 #include <stdlib.h>
21 #include <string.h>
22 #include <sys/mman.h>
23 #include <sys/ptrace.h>
24 #include <sys/types.h>
25 #include <unistd.h>
26
27 #include <vector>
28
29 #include <android-base/test_utils.h>
30 #include <android-base/file.h>
31 #include <gtest/gtest.h>
32
33 #include <unwindstack/Memory.h>
34
35 #include "MemoryFake.h"
36 #include "TestUtils.h"
37
38 namespace unwindstack {
39
40 class MemoryRemoteTest : public ::testing::Test {
41 protected:
Attach(pid_t pid)42 static bool Attach(pid_t pid) {
43 if (ptrace(PTRACE_ATTACH, pid, 0, 0) == -1) {
44 return false;
45 }
46
47 return TestQuiescePid(pid);
48 }
49
Detach(pid_t pid)50 static bool Detach(pid_t pid) {
51 return ptrace(PTRACE_DETACH, pid, 0, 0) == 0;
52 }
53
54 static constexpr size_t NS_PER_SEC = 1000000000ULL;
55 };
56
TEST_F(MemoryRemoteTest,read)57 TEST_F(MemoryRemoteTest, read) {
58 std::vector<uint8_t> src(1024);
59 memset(src.data(), 0x4c, 1024);
60
61 pid_t pid;
62 if ((pid = fork()) == 0) {
63 while (true);
64 exit(1);
65 }
66 ASSERT_LT(0, pid);
67 TestScopedPidReaper reap(pid);
68
69 ASSERT_TRUE(Attach(pid));
70
71 MemoryRemote remote(pid);
72
73 std::vector<uint8_t> dst(1024);
74 ASSERT_TRUE(remote.ReadFully(reinterpret_cast<uint64_t>(src.data()), dst.data(), 1024));
75 for (size_t i = 0; i < 1024; i++) {
76 ASSERT_EQ(0x4cU, dst[i]) << "Failed at byte " << i;
77 }
78
79 ASSERT_TRUE(Detach(pid));
80 }
81
TEST_F(MemoryRemoteTest,read_large)82 TEST_F(MemoryRemoteTest, read_large) {
83 static constexpr size_t kTotalPages = 245;
84 std::vector<uint8_t> src(kTotalPages * getpagesize());
85 for (size_t i = 0; i < kTotalPages; i++) {
86 memset(&src[i * getpagesize()], i, getpagesize());
87 }
88
89 pid_t pid;
90 if ((pid = fork()) == 0) {
91 while (true)
92 ;
93 exit(1);
94 }
95 ASSERT_LT(0, pid);
96 TestScopedPidReaper reap(pid);
97
98 ASSERT_TRUE(Attach(pid));
99
100 MemoryRemote remote(pid);
101
102 std::vector<uint8_t> dst(kTotalPages * getpagesize());
103 ASSERT_TRUE(remote.ReadFully(reinterpret_cast<uint64_t>(src.data()), dst.data(), src.size()));
104 for (size_t i = 0; i < kTotalPages * getpagesize(); i++) {
105 ASSERT_EQ(i / getpagesize(), dst[i]) << "Failed at byte " << i;
106 }
107
108 ASSERT_TRUE(Detach(pid));
109 }
110
TEST_F(MemoryRemoteTest,read_partial)111 TEST_F(MemoryRemoteTest, read_partial) {
112 char* mapping = static_cast<char*>(
113 mmap(nullptr, 4 * getpagesize(), PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0));
114 ASSERT_NE(MAP_FAILED, mapping);
115 memset(mapping, 0x4c, 4 * getpagesize());
116 ASSERT_EQ(0, mprotect(mapping + getpagesize(), getpagesize(), PROT_NONE));
117 ASSERT_EQ(0, munmap(mapping + 3 * getpagesize(), getpagesize()));
118
119 pid_t pid;
120 if ((pid = fork()) == 0) {
121 while (true)
122 ;
123 exit(1);
124 }
125 ASSERT_LT(0, pid);
126 TestScopedPidReaper reap(pid);
127
128 // Unmap from our process.
129 ASSERT_EQ(0, munmap(mapping, 3 * getpagesize()));
130
131 ASSERT_TRUE(Attach(pid));
132
133 MemoryRemote remote(pid);
134
135 std::vector<uint8_t> dst(4096);
136 size_t bytes =
137 remote.Read(reinterpret_cast<uint64_t>(mapping + getpagesize() - 1024), dst.data(), 4096);
138 // Some read methods can read PROT_NONE maps, allow that.
139 ASSERT_LE(1024U, bytes);
140 for (size_t i = 0; i < bytes; i++) {
141 ASSERT_EQ(0x4cU, dst[i]) << "Failed at byte " << i;
142 }
143
144 // Now verify that reading stops at the end of a map.
145 bytes =
146 remote.Read(reinterpret_cast<uint64_t>(mapping + 3 * getpagesize() - 1024), dst.data(), 4096);
147 ASSERT_EQ(1024U, bytes);
148 for (size_t i = 0; i < bytes; i++) {
149 ASSERT_EQ(0x4cU, dst[i]) << "Failed at byte " << i;
150 }
151
152 ASSERT_TRUE(Detach(pid));
153 }
154
TEST_F(MemoryRemoteTest,read_fail)155 TEST_F(MemoryRemoteTest, read_fail) {
156 int pagesize = getpagesize();
157 void* src = mmap(nullptr, pagesize * 2, PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE,-1, 0);
158 memset(src, 0x4c, pagesize * 2);
159 ASSERT_NE(MAP_FAILED, src);
160 // Put a hole right after the first page.
161 ASSERT_EQ(0, munmap(reinterpret_cast<void*>(reinterpret_cast<uintptr_t>(src) + pagesize),
162 pagesize));
163
164 pid_t pid;
165 if ((pid = fork()) == 0) {
166 while (true);
167 exit(1);
168 }
169 ASSERT_LT(0, pid);
170 TestScopedPidReaper reap(pid);
171
172 ASSERT_TRUE(Attach(pid));
173
174 MemoryRemote remote(pid);
175
176 std::vector<uint8_t> dst(pagesize);
177 ASSERT_TRUE(remote.ReadFully(reinterpret_cast<uint64_t>(src), dst.data(), pagesize));
178 for (size_t i = 0; i < 1024; i++) {
179 ASSERT_EQ(0x4cU, dst[i]) << "Failed at byte " << i;
180 }
181
182 ASSERT_FALSE(remote.ReadFully(reinterpret_cast<uint64_t>(src) + pagesize, dst.data(), 1));
183 ASSERT_TRUE(remote.ReadFully(reinterpret_cast<uint64_t>(src) + pagesize - 1, dst.data(), 1));
184 ASSERT_FALSE(remote.ReadFully(reinterpret_cast<uint64_t>(src) + pagesize - 4, dst.data(), 8));
185
186 // Check overflow condition is caught properly.
187 ASSERT_FALSE(remote.ReadFully(UINT64_MAX - 100, dst.data(), 200));
188
189 ASSERT_EQ(0, munmap(src, pagesize));
190
191 ASSERT_TRUE(Detach(pid));
192 }
193
TEST_F(MemoryRemoteTest,read_overflow)194 TEST_F(MemoryRemoteTest, read_overflow) {
195 pid_t pid;
196 if ((pid = fork()) == 0) {
197 while (true)
198 ;
199 exit(1);
200 }
201 ASSERT_LT(0, pid);
202 TestScopedPidReaper reap(pid);
203
204 ASSERT_TRUE(Attach(pid));
205
206 MemoryRemote remote(pid);
207
208 // Check overflow condition is caught properly.
209 std::vector<uint8_t> dst(200);
210 ASSERT_FALSE(remote.ReadFully(UINT64_MAX - 100, dst.data(), 200));
211
212 ASSERT_TRUE(Detach(pid));
213 }
214
TEST_F(MemoryRemoteTest,read_illegal)215 TEST_F(MemoryRemoteTest, read_illegal) {
216 pid_t pid;
217 if ((pid = fork()) == 0) {
218 while (true);
219 exit(1);
220 }
221 ASSERT_LT(0, pid);
222 TestScopedPidReaper reap(pid);
223
224 ASSERT_TRUE(Attach(pid));
225
226 MemoryRemote remote(pid);
227
228 std::vector<uint8_t> dst(100);
229 ASSERT_FALSE(remote.ReadFully(0, dst.data(), 1));
230 ASSERT_FALSE(remote.ReadFully(0, dst.data(), 100));
231
232 ASSERT_TRUE(Detach(pid));
233 }
234
TEST_F(MemoryRemoteTest,read_mprotect_hole)235 TEST_F(MemoryRemoteTest, read_mprotect_hole) {
236 size_t page_size = getpagesize();
237 void* mapping =
238 mmap(nullptr, 3 * getpagesize(), PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
239 ASSERT_NE(MAP_FAILED, mapping);
240 memset(mapping, 0xFF, 3 * page_size);
241 ASSERT_EQ(0, mprotect(static_cast<char*>(mapping) + page_size, page_size, PROT_NONE));
242
243 pid_t pid;
244 if ((pid = fork()) == 0) {
245 while (true);
246 exit(1);
247 }
248 ASSERT_LT(0, pid);
249 TestScopedPidReaper reap(pid);
250
251 ASSERT_EQ(0, munmap(mapping, 3 * page_size));
252
253 ASSERT_TRUE(Attach(pid));
254
255 MemoryRemote remote(pid);
256 std::vector<uint8_t> dst(getpagesize() * 4, 0xCC);
257 size_t read_size = remote.Read(reinterpret_cast<uint64_t>(mapping), dst.data(), page_size * 3);
258 // Some read methods can read PROT_NONE maps, allow that.
259 ASSERT_LE(page_size, read_size);
260 for (size_t i = 0; i < read_size; ++i) {
261 ASSERT_EQ(0xFF, dst[i]);
262 }
263 for (size_t i = read_size; i < dst.size(); ++i) {
264 ASSERT_EQ(0xCC, dst[i]);
265 }
266 }
267
TEST_F(MemoryRemoteTest,read_munmap_hole)268 TEST_F(MemoryRemoteTest, read_munmap_hole) {
269 size_t page_size = getpagesize();
270 void* mapping =
271 mmap(nullptr, 3 * getpagesize(), PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
272 ASSERT_NE(MAP_FAILED, mapping);
273 memset(mapping, 0xFF, 3 * page_size);
274 ASSERT_EQ(0, munmap(static_cast<char*>(mapping) + page_size, page_size));
275
276 pid_t pid;
277 if ((pid = fork()) == 0) {
278 while (true)
279 ;
280 exit(1);
281 }
282 ASSERT_LT(0, pid);
283 TestScopedPidReaper reap(pid);
284
285 ASSERT_EQ(0, munmap(mapping, page_size));
286 ASSERT_EQ(0, munmap(static_cast<char*>(mapping) + 2 * page_size, page_size));
287
288 ASSERT_TRUE(Attach(pid));
289
290 MemoryRemote remote(pid);
291 std::vector<uint8_t> dst(getpagesize() * 4, 0xCC);
292 size_t read_size = remote.Read(reinterpret_cast<uint64_t>(mapping), dst.data(), page_size * 3);
293 ASSERT_EQ(page_size, read_size);
294 for (size_t i = 0; i < read_size; ++i) {
295 ASSERT_EQ(0xFF, dst[i]);
296 }
297 for (size_t i = read_size; i < dst.size(); ++i) {
298 ASSERT_EQ(0xCC, dst[i]);
299 }
300 }
301
302 // Verify that the memory remote object chooses a memory read function
303 // properly. Either process_vm_readv or ptrace.
TEST_F(MemoryRemoteTest,read_choose_correctly)304 TEST_F(MemoryRemoteTest, read_choose_correctly) {
305 size_t page_size = getpagesize();
306 void* mapping =
307 mmap(nullptr, 2 * getpagesize(), PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
308 ASSERT_NE(MAP_FAILED, mapping);
309 memset(mapping, 0xFC, 2 * page_size);
310 ASSERT_EQ(0, mprotect(static_cast<char*>(mapping), page_size, PROT_NONE));
311
312 pid_t pid;
313 if ((pid = fork()) == 0) {
314 while (true)
315 ;
316 exit(1);
317 }
318 ASSERT_LT(0, pid);
319 TestScopedPidReaper reap(pid);
320
321 ASSERT_EQ(0, munmap(mapping, 2 * page_size));
322
323 ASSERT_TRUE(Attach(pid));
324
325 // We know that process_vm_readv of a mprotect'd PROT_NONE region will fail.
326 // Read from the PROT_NONE area first to force the choice of ptrace.
327 MemoryRemote remote_ptrace(pid);
328 uint32_t value;
329 size_t bytes = remote_ptrace.Read(reinterpret_cast<uint64_t>(mapping), &value, sizeof(value));
330 ASSERT_EQ(sizeof(value), bytes);
331 ASSERT_EQ(0xfcfcfcfcU, value);
332 bytes = remote_ptrace.Read(reinterpret_cast<uint64_t>(mapping) + page_size, &value, sizeof(value));
333 ASSERT_EQ(sizeof(value), bytes);
334 ASSERT_EQ(0xfcfcfcfcU, value);
335 bytes = remote_ptrace.Read(reinterpret_cast<uint64_t>(mapping), &value, sizeof(value));
336 ASSERT_EQ(sizeof(value), bytes);
337 ASSERT_EQ(0xfcfcfcfcU, value);
338
339 // Now verify that choosing process_vm_readv results in failing reads of
340 // the PROT_NONE part of the map. Read from a valid map first which
341 // should prefer process_vm_readv, and keep that as the read function.
342 MemoryRemote remote_readv(pid);
343 bytes = remote_readv.Read(reinterpret_cast<uint64_t>(mapping) + page_size, &value, sizeof(value));
344 ASSERT_EQ(sizeof(value), bytes);
345 ASSERT_EQ(0xfcfcfcfcU, value);
346 bytes = remote_readv.Read(reinterpret_cast<uint64_t>(mapping), &value, sizeof(value));
347 ASSERT_EQ(0U, bytes);
348 bytes = remote_readv.Read(reinterpret_cast<uint64_t>(mapping) + page_size, &value, sizeof(value));
349 ASSERT_EQ(sizeof(value), bytes);
350 ASSERT_EQ(0xfcfcfcfcU, value);
351 }
352
353 } // namespace unwindstack
354