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 <elf.h>
18 #include <errno.h>
19 #include <signal.h>
20 #include <stdint.h>
21 #include <stdlib.h>
22 #include <string.h>
23 #include <sys/mman.h>
24 #include <sys/ptrace.h>
25 #include <sys/types.h>
26 #include <time.h>
27 #include <unistd.h>
28 
29 #include <vector>
30 
31 #include <android-base/file.h>
32 #include <android-base/test_utils.h>
33 #include <gtest/gtest.h>
34 
35 #include <unwindstack/Memory.h>
36 
37 #include "MemoryFake.h"
38 #include "Symbols.h"
39 
40 namespace unwindstack {
41 
42 template <typename TypeParam>
43 class SymbolsTest : public ::testing::Test {
44  protected:
SetUp()45   void SetUp() override { memory_.Clear(); }
46 
InitSym(TypeParam * sym,uint32_t st_value,uint32_t st_size,uint32_t st_name)47   void InitSym(TypeParam* sym, uint32_t st_value, uint32_t st_size, uint32_t st_name) {
48     memset(sym, 0, sizeof(*sym));
49     sym->st_info = STT_FUNC;
50     sym->st_value = st_value;
51     sym->st_size = st_size;
52     sym->st_name = st_name;
53     sym->st_shndx = SHN_COMMON;
54   }
55 
56   MemoryFake memory_;
57 };
58 TYPED_TEST_SUITE_P(SymbolsTest);
59 
TYPED_TEST_P(SymbolsTest,function_bounds_check)60 TYPED_TEST_P(SymbolsTest, function_bounds_check) {
61   Symbols symbols(0x1000, sizeof(TypeParam), sizeof(TypeParam), 0x2000, 0x100);
62 
63   TypeParam sym;
64   this->InitSym(&sym, 0x5000, 0x10, 0x40);
65   uint64_t offset = 0x1000;
66   this->memory_.SetMemory(offset, &sym, sizeof(sym));
67 
68   std::string fake_name("fake_function");
69   this->memory_.SetMemory(0x2040, fake_name.c_str(), fake_name.size() + 1);
70 
71   std::string name;
72   uint64_t func_offset;
73   ASSERT_TRUE(symbols.GetName<TypeParam>(0x5000, &this->memory_, &name, &func_offset));
74   ASSERT_EQ("fake_function", name);
75   ASSERT_EQ(0U, func_offset);
76 
77   name.clear();
78   ASSERT_TRUE(symbols.GetName<TypeParam>(0x500f, &this->memory_, &name, &func_offset));
79   ASSERT_EQ("fake_function", name);
80   ASSERT_EQ(0xfU, func_offset);
81 
82   // Check one before and one after the function.
83   ASSERT_FALSE(symbols.GetName<TypeParam>(0x4fff, &this->memory_, &name, &func_offset));
84   ASSERT_FALSE(symbols.GetName<TypeParam>(0x5010, &this->memory_, &name, &func_offset));
85 }
86 
TYPED_TEST_P(SymbolsTest,no_symbol)87 TYPED_TEST_P(SymbolsTest, no_symbol) {
88   Symbols symbols(0x1000, sizeof(TypeParam), sizeof(TypeParam), 0x2000, 0x100);
89 
90   TypeParam sym;
91   this->InitSym(&sym, 0x5000, 0x10, 0x40);
92   uint64_t offset = 0x1000;
93   this->memory_.SetMemory(offset, &sym, sizeof(sym));
94 
95   std::string fake_name("fake_function");
96   this->memory_.SetMemory(0x2040, fake_name.c_str(), fake_name.size() + 1);
97 
98   // First verify that we can get the name.
99   std::string name;
100   uint64_t func_offset;
101   ASSERT_TRUE(symbols.GetName<TypeParam>(0x5000, &this->memory_, &name, &func_offset));
102   ASSERT_EQ("fake_function", name);
103   ASSERT_EQ(0U, func_offset);
104 
105   // Now modify the info field so it's no longer a function.
106   sym.st_info = 0;
107   this->memory_.SetMemory(offset, &sym, sizeof(sym));
108   // Clear the cache to force the symbol data to be re-read.
109   symbols.ClearCache();
110   ASSERT_FALSE(symbols.GetName<TypeParam>(0x5000, &this->memory_, &name, &func_offset));
111 
112   // Set the function back, and set the shndx to UNDEF.
113   sym.st_info = STT_FUNC;
114   sym.st_shndx = SHN_UNDEF;
115   this->memory_.SetMemory(offset, &sym, sizeof(sym));
116   // Clear the cache to force the symbol data to be re-read.
117   symbols.ClearCache();
118   ASSERT_FALSE(symbols.GetName<TypeParam>(0x5000, &this->memory_, &name, &func_offset));
119 }
120 
TYPED_TEST_P(SymbolsTest,multiple_entries)121 TYPED_TEST_P(SymbolsTest, multiple_entries) {
122   Symbols symbols(0x1000, sizeof(TypeParam) * 3, sizeof(TypeParam), 0x2000, 0x500);
123 
124   TypeParam sym;
125   uint64_t offset = 0x1000;
126   std::string fake_name;
127 
128   this->InitSym(&sym, 0x5000, 0x10, 0x40);
129   this->memory_.SetMemory(offset, &sym, sizeof(sym));
130   fake_name = "function_one";
131   this->memory_.SetMemory(0x2040, fake_name.c_str(), fake_name.size() + 1);
132   offset += sizeof(sym);
133 
134   this->InitSym(&sym, 0x3004, 0x200, 0x100);
135   this->memory_.SetMemory(offset, &sym, sizeof(sym));
136   fake_name = "function_two";
137   this->memory_.SetMemory(0x2100, fake_name.c_str(), fake_name.size() + 1);
138   offset += sizeof(sym);
139 
140   this->InitSym(&sym, 0xa010, 0x20, 0x230);
141   this->memory_.SetMemory(offset, &sym, sizeof(sym));
142   fake_name = "function_three";
143   this->memory_.SetMemory(0x2230, fake_name.c_str(), fake_name.size() + 1);
144 
145   std::string name;
146   uint64_t func_offset;
147   ASSERT_TRUE(symbols.GetName<TypeParam>(0x3005, &this->memory_, &name, &func_offset));
148   ASSERT_EQ("function_two", name);
149   ASSERT_EQ(1U, func_offset);
150 
151   name.clear();
152   ASSERT_TRUE(symbols.GetName<TypeParam>(0x5004, &this->memory_, &name, &func_offset));
153   ASSERT_EQ("function_one", name);
154   ASSERT_EQ(4U, func_offset);
155 
156   name.clear();
157   ASSERT_TRUE(symbols.GetName<TypeParam>(0xa011, &this->memory_, &name, &func_offset));
158   ASSERT_EQ("function_three", name);
159   ASSERT_EQ(1U, func_offset);
160 
161   // Reget some of the others to verify getting one function name doesn't
162   // affect any of the next calls.
163   name.clear();
164   ASSERT_TRUE(symbols.GetName<TypeParam>(0x5008, &this->memory_, &name, &func_offset));
165   ASSERT_EQ("function_one", name);
166   ASSERT_EQ(8U, func_offset);
167 
168   name.clear();
169   ASSERT_TRUE(symbols.GetName<TypeParam>(0x3008, &this->memory_, &name, &func_offset));
170   ASSERT_EQ("function_two", name);
171   ASSERT_EQ(4U, func_offset);
172 
173   name.clear();
174   ASSERT_TRUE(symbols.GetName<TypeParam>(0xa01a, &this->memory_, &name, &func_offset));
175   ASSERT_EQ("function_three", name);
176   ASSERT_EQ(0xaU, func_offset);
177 }
178 
TYPED_TEST_P(SymbolsTest,multiple_entries_nonstandard_size)179 TYPED_TEST_P(SymbolsTest, multiple_entries_nonstandard_size) {
180   uint64_t entry_size = sizeof(TypeParam) + 5;
181   Symbols symbols(0x1000, entry_size * 3, entry_size, 0x2000, 0x500);
182 
183   TypeParam sym;
184   uint64_t offset = 0x1000;
185   std::string fake_name;
186 
187   this->InitSym(&sym, 0x5000, 0x10, 0x40);
188   this->memory_.SetMemoryBlock(offset, entry_size, 0);
189   this->memory_.SetMemory(offset, &sym, sizeof(sym));
190   fake_name = "function_one";
191   this->memory_.SetMemory(0x2040, fake_name.c_str(), fake_name.size() + 1);
192   offset += entry_size;
193 
194   this->InitSym(&sym, 0x3004, 0x200, 0x100);
195   this->memory_.SetMemoryBlock(offset, entry_size, 0);
196   this->memory_.SetMemory(offset, &sym, sizeof(sym));
197   fake_name = "function_two";
198   this->memory_.SetMemory(0x2100, fake_name.c_str(), fake_name.size() + 1);
199   offset += entry_size;
200 
201   this->InitSym(&sym, 0xa010, 0x20, 0x230);
202   this->memory_.SetMemoryBlock(offset, entry_size, 0);
203   this->memory_.SetMemory(offset, &sym, sizeof(sym));
204   fake_name = "function_three";
205   this->memory_.SetMemory(0x2230, fake_name.c_str(), fake_name.size() + 1);
206 
207   std::string name;
208   uint64_t func_offset;
209   ASSERT_TRUE(symbols.GetName<TypeParam>(0x3005, &this->memory_, &name, &func_offset));
210   ASSERT_EQ("function_two", name);
211   ASSERT_EQ(1U, func_offset);
212 
213   name.clear();
214   ASSERT_TRUE(symbols.GetName<TypeParam>(0x5004, &this->memory_, &name, &func_offset));
215   ASSERT_EQ("function_one", name);
216   ASSERT_EQ(4U, func_offset);
217 
218   name.clear();
219   ASSERT_TRUE(symbols.GetName<TypeParam>(0xa011, &this->memory_, &name, &func_offset));
220   ASSERT_EQ("function_three", name);
221   ASSERT_EQ(1U, func_offset);
222 }
223 
TYPED_TEST_P(SymbolsTest,symtab_value_out_of_bounds)224 TYPED_TEST_P(SymbolsTest, symtab_value_out_of_bounds) {
225   Symbols symbols_end_at_100(0x1000, sizeof(TypeParam) * 2, sizeof(TypeParam), 0x2000, 0x100);
226   Symbols symbols_end_at_200(0x1000, sizeof(TypeParam) * 2, sizeof(TypeParam), 0x2000, 0x200);
227 
228   TypeParam sym;
229   uint64_t offset = 0x1000;
230 
231   this->InitSym(&sym, 0x5000, 0x10, 0xfb);
232   this->memory_.SetMemory(offset, &sym, sizeof(sym));
233   offset += sizeof(sym);
234 
235   this->InitSym(&sym, 0x3000, 0x10, 0x100);
236   this->memory_.SetMemory(offset, &sym, sizeof(sym));
237 
238   // Put the name across the end of the tab.
239   std::string fake_name("fake_function");
240   this->memory_.SetMemory(0x20fb, fake_name.c_str(), fake_name.size() + 1);
241 
242   std::string name;
243   uint64_t func_offset;
244   // Verify that we can get the function name properly for both entries.
245   ASSERT_TRUE(symbols_end_at_200.GetName<TypeParam>(0x5000, &this->memory_, &name, &func_offset));
246   ASSERT_EQ("fake_function", name);
247   ASSERT_EQ(0U, func_offset);
248   ASSERT_TRUE(symbols_end_at_200.GetName<TypeParam>(0x3000, &this->memory_, &name, &func_offset));
249   ASSERT_EQ("function", name);
250   ASSERT_EQ(0U, func_offset);
251 
252   // Now use the symbol table that ends at 0x100.
253   ASSERT_FALSE(symbols_end_at_100.GetName<TypeParam>(0x5000, &this->memory_, &name, &func_offset));
254   ASSERT_FALSE(symbols_end_at_100.GetName<TypeParam>(0x3000, &this->memory_, &name, &func_offset));
255 }
256 
257 // Verify the entire func table is cached.
TYPED_TEST_P(SymbolsTest,symtab_read_cached)258 TYPED_TEST_P(SymbolsTest, symtab_read_cached) {
259   Symbols symbols(0x1000, 3 * sizeof(TypeParam), sizeof(TypeParam), 0xa000, 0x1000);
260 
261   TypeParam sym;
262   uint64_t offset = 0x1000;
263 
264   // Make sure that these entries are not in ascending order.
265   this->InitSym(&sym, 0x5000, 0x10, 0x100);
266   this->memory_.SetMemory(offset, &sym, sizeof(sym));
267   offset += sizeof(sym);
268 
269   this->InitSym(&sym, 0x2000, 0x300, 0x200);
270   this->memory_.SetMemory(offset, &sym, sizeof(sym));
271   offset += sizeof(sym);
272 
273   this->InitSym(&sym, 0x1000, 0x100, 0x300);
274   this->memory_.SetMemory(offset, &sym, sizeof(sym));
275   offset += sizeof(sym);
276 
277   // Do call that should cache all of the entries (except the string data).
278   std::string name;
279   uint64_t func_offset;
280   ASSERT_FALSE(symbols.GetName<TypeParam>(0x5000, &this->memory_, &name, &func_offset));
281   ASSERT_FALSE(symbols.GetName<TypeParam>(0x2000, &this->memory_, &name, &func_offset));
282   ASSERT_FALSE(symbols.GetName<TypeParam>(0x1000, &this->memory_, &name, &func_offset));
283   this->memory_.Clear();
284   ASSERT_FALSE(symbols.GetName<TypeParam>(0x6000, &this->memory_, &name, &func_offset));
285 
286   // Clear the memory and only put the symbol data string data in memory.
287   this->memory_.Clear();
288 
289   std::string fake_name;
290   fake_name = "first_entry";
291   this->memory_.SetMemory(0xa100, fake_name.c_str(), fake_name.size() + 1);
292   fake_name = "second_entry";
293   this->memory_.SetMemory(0xa200, fake_name.c_str(), fake_name.size() + 1);
294   fake_name = "third_entry";
295   this->memory_.SetMemory(0xa300, fake_name.c_str(), fake_name.size() + 1);
296 
297   ASSERT_TRUE(symbols.GetName<TypeParam>(0x5001, &this->memory_, &name, &func_offset));
298   ASSERT_EQ("first_entry", name);
299   ASSERT_EQ(1U, func_offset);
300 
301   ASSERT_TRUE(symbols.GetName<TypeParam>(0x2002, &this->memory_, &name, &func_offset));
302   ASSERT_EQ("second_entry", name);
303   ASSERT_EQ(2U, func_offset);
304 
305   ASSERT_TRUE(symbols.GetName<TypeParam>(0x1003, &this->memory_, &name, &func_offset));
306   ASSERT_EQ("third_entry", name);
307   ASSERT_EQ(3U, func_offset);
308 }
309 
TYPED_TEST_P(SymbolsTest,get_global)310 TYPED_TEST_P(SymbolsTest, get_global) {
311   uint64_t start_offset = 0x1000;
312   uint64_t str_offset = 0xa000;
313   Symbols symbols(start_offset, 4 * sizeof(TypeParam), sizeof(TypeParam), str_offset, 0x1000);
314 
315   TypeParam sym;
316   memset(&sym, 0, sizeof(sym));
317   sym.st_shndx = SHN_COMMON;
318   sym.st_info = STT_OBJECT | (STB_GLOBAL << 4);
319   sym.st_name = 0x100;
320   this->memory_.SetMemory(start_offset, &sym, sizeof(sym));
321   this->memory_.SetMemory(str_offset + 0x100, "global_0");
322 
323   start_offset += sizeof(sym);
324   memset(&sym, 0, sizeof(sym));
325   sym.st_shndx = SHN_COMMON;
326   sym.st_info = STT_FUNC;
327   sym.st_name = 0x200;
328   sym.st_value = 0x10000;
329   sym.st_size = 0x100;
330   this->memory_.SetMemory(start_offset, &sym, sizeof(sym));
331   this->memory_.SetMemory(str_offset + 0x200, "function_0");
332 
333   start_offset += sizeof(sym);
334   memset(&sym, 0, sizeof(sym));
335   sym.st_shndx = SHN_COMMON;
336   sym.st_info = STT_OBJECT | (STB_GLOBAL << 4);
337   sym.st_name = 0x300;
338   this->memory_.SetMemory(start_offset, &sym, sizeof(sym));
339   this->memory_.SetMemory(str_offset + 0x300, "global_1");
340 
341   start_offset += sizeof(sym);
342   memset(&sym, 0, sizeof(sym));
343   sym.st_shndx = SHN_COMMON;
344   sym.st_info = STT_FUNC;
345   sym.st_name = 0x400;
346   sym.st_value = 0x12000;
347   sym.st_size = 0x100;
348   this->memory_.SetMemory(start_offset, &sym, sizeof(sym));
349   this->memory_.SetMemory(str_offset + 0x400, "function_1");
350 
351   uint64_t offset;
352   EXPECT_TRUE(symbols.GetGlobal<TypeParam>(&this->memory_, "global_0", &offset));
353   EXPECT_TRUE(symbols.GetGlobal<TypeParam>(&this->memory_, "global_1", &offset));
354   EXPECT_TRUE(symbols.GetGlobal<TypeParam>(&this->memory_, "global_0", &offset));
355   EXPECT_TRUE(symbols.GetGlobal<TypeParam>(&this->memory_, "global_1", &offset));
356 
357   EXPECT_FALSE(symbols.GetGlobal<TypeParam>(&this->memory_, "function_0", &offset));
358   EXPECT_FALSE(symbols.GetGlobal<TypeParam>(&this->memory_, "function_1", &offset));
359 
360   std::string name;
361   EXPECT_TRUE(symbols.GetName<TypeParam>(0x10002, &this->memory_, &name, &offset));
362   EXPECT_EQ("function_0", name);
363   EXPECT_EQ(2U, offset);
364 
365   EXPECT_TRUE(symbols.GetName<TypeParam>(0x12004, &this->memory_, &name, &offset));
366   EXPECT_EQ("function_1", name);
367   EXPECT_EQ(4U, offset);
368 }
369 
370 REGISTER_TYPED_TEST_SUITE_P(SymbolsTest, function_bounds_check, no_symbol, multiple_entries,
371                             multiple_entries_nonstandard_size, symtab_value_out_of_bounds,
372                             symtab_read_cached, get_global);
373 
374 typedef ::testing::Types<Elf32_Sym, Elf64_Sym> SymbolsTestTypes;
375 INSTANTIATE_TYPED_TEST_SUITE_P(Libunwindstack, SymbolsTest, SymbolsTestTypes);
376 
377 }  // namespace unwindstack
378