1 /*
2  * Copyright (C) 2015 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 "read_elf.h"
18 
19 #include <gtest/gtest.h>
20 
21 #include <map>
22 
23 #include <android-base/file.h>
24 
25 #include "get_test_data.h"
26 #include "read_apk.h"
27 #include "test_util.h"
28 #include "utils.h"
29 
30 #define ELF_NOTE_GNU "GNU"
31 #define NT_GNU_BUILD_ID 3
32 
33 using namespace simpleperf;
34 
35 // @CddTest = 6.1/C-0-2
TEST(read_elf,GetBuildIdFromNoteSection)36 TEST(read_elf, GetBuildIdFromNoteSection) {
37   BuildId build_id;
38   std::vector<char> data;
39   // Fail to read build id for no data.
40   ASSERT_FALSE(GetBuildIdFromNoteSection(data.data(), 0, &build_id));
41 
42   // Read build id from data starting from different alignment addresses.
43   char build_id_data[20];
44   for (int i = 0; i < 20; ++i) {
45     build_id_data[i] = i;
46   }
47   BuildId expected_build_id(build_id_data, 20);
48   data.resize(100, '\0');
49 
50   for (size_t alignment = 0; alignment <= 3; ++alignment) {
51     char* start = data.data() + alignment;
52     char* p = start;
53     uint32_t type = NT_GNU_BUILD_ID;
54     uint32_t namesz = 4;
55     uint32_t descsz = 20;
56     MoveToBinaryFormat(namesz, p);
57     MoveToBinaryFormat(descsz, p);
58     MoveToBinaryFormat(type, p);
59     MoveToBinaryFormat(ELF_NOTE_GNU, 4, p);
60     MoveToBinaryFormat(build_id_data, 20, p);
61     ASSERT_TRUE(GetBuildIdFromNoteSection(start, p - start, &build_id));
62     ASSERT_TRUE(build_id == expected_build_id);
63   }
64 }
65 
66 // @CddTest = 6.1/C-0-2
TEST(read_elf,GetBuildIdFromElfFile)67 TEST(read_elf, GetBuildIdFromElfFile) {
68   BuildId build_id;
69   ElfStatus status;
70   auto elf = ElfFile::Open(GetTestData(ELF_FILE), &status);
71   ASSERT_EQ(status, ElfStatus::NO_ERROR);
72   ASSERT_EQ(ElfStatus::NO_ERROR, elf->GetBuildId(&build_id));
73   ASSERT_EQ(build_id, BuildId(elf_file_build_id));
74 }
75 
76 // @CddTest = 6.1/C-0-2
TEST(read_elf,GetBuildIdFromEmbeddedElfFile)77 TEST(read_elf, GetBuildIdFromEmbeddedElfFile) {
78   BuildId build_id;
79   ElfStatus status;
80   std::string path = GetUrlInApk(APK_FILE, NATIVELIB_IN_APK);
81   auto elf = ElfFile::Open(GetTestData(path), &status);
82   ASSERT_EQ(status, ElfStatus::NO_ERROR);
83   ASSERT_EQ(ElfStatus::NO_ERROR, elf->GetBuildId(&build_id));
84   ASSERT_EQ(build_id, native_lib_build_id);
85 }
86 
ParseSymbol(const ElfFileSymbol & symbol,std::map<std::string,ElfFileSymbol> * symbols)87 void ParseSymbol(const ElfFileSymbol& symbol, std::map<std::string, ElfFileSymbol>* symbols) {
88   (*symbols)[symbol.name] = symbol;
89 }
90 
CheckGlobalVariableSymbols(const std::map<std::string,ElfFileSymbol> & symbols)91 static void CheckGlobalVariableSymbols(const std::map<std::string, ElfFileSymbol>& symbols) {
92   auto pos = symbols.find("GlobalVar");
93   ASSERT_NE(pos, symbols.end());
94   ASSERT_FALSE(pos->second.is_func);
95 }
96 
CheckFunctionSymbols(const std::map<std::string,ElfFileSymbol> & symbols)97 static void CheckFunctionSymbols(const std::map<std::string, ElfFileSymbol>& symbols) {
98   auto pos = symbols.find("GlobalFunc");
99   ASSERT_NE(pos, symbols.end());
100   ASSERT_TRUE(pos->second.is_func);
101   ASSERT_TRUE(pos->second.is_in_text_section);
102 }
103 
CheckElfFileSymbols(const std::map<std::string,ElfFileSymbol> & symbols)104 void CheckElfFileSymbols(const std::map<std::string, ElfFileSymbol>& symbols) {
105   CheckGlobalVariableSymbols(symbols);
106   CheckFunctionSymbols(symbols);
107 }
108 
109 // @CddTest = 6.1/C-0-2
TEST(read_elf,parse_symbols_from_elf_file_with_correct_build_id)110 TEST(read_elf, parse_symbols_from_elf_file_with_correct_build_id) {
111   std::map<std::string, ElfFileSymbol> symbols;
112   ElfStatus status;
113   auto elf = ElfFile::Open(GetTestData(ELF_FILE), &elf_file_build_id, &status);
114   ASSERT_EQ(ElfStatus::NO_ERROR, status);
115   ASSERT_EQ(ElfStatus::NO_ERROR,
116             elf->ParseSymbols(std::bind(ParseSymbol, std::placeholders::_1, &symbols)));
117   CheckElfFileSymbols(symbols);
118 }
119 
120 // @CddTest = 6.1/C-0-2
TEST(read_elf,parse_symbols_from_elf_file_without_build_id)121 TEST(read_elf, parse_symbols_from_elf_file_without_build_id) {
122   std::map<std::string, ElfFileSymbol> symbols;
123   ElfStatus status;
124   // Test no build_id.
125   auto elf = ElfFile::Open(GetTestData(ELF_FILE), &status);
126   ASSERT_EQ(ElfStatus::NO_ERROR, status);
127   ASSERT_EQ(ElfStatus::NO_ERROR,
128             elf->ParseSymbols(std::bind(ParseSymbol, std::placeholders::_1, &symbols)));
129   CheckElfFileSymbols(symbols);
130 
131   // Test empty build id.
132   symbols.clear();
133   BuildId build_id;
134   elf = ElfFile::Open(GetTestData(ELF_FILE), &build_id, &status);
135   ASSERT_EQ(ElfStatus::NO_ERROR, status);
136   ASSERT_EQ(ElfStatus::NO_ERROR,
137             elf->ParseSymbols(std::bind(ParseSymbol, std::placeholders::_1, &symbols)));
138   CheckElfFileSymbols(symbols);
139 }
140 
141 // @CddTest = 6.1/C-0-2
TEST(read_elf,parse_symbols_from_elf_file_with_wrong_build_id)142 TEST(read_elf, parse_symbols_from_elf_file_with_wrong_build_id) {
143   BuildId build_id("01010101010101010101");
144   std::map<std::string, ElfFileSymbol> symbols;
145   ElfStatus status;
146   auto elf = ElfFile::Open(GetTestData(ELF_FILE), &build_id, &status);
147   ASSERT_EQ(ElfStatus::BUILD_ID_MISMATCH, status);
148 }
149 
150 // @CddTest = 6.1/C-0-2
TEST(read_elf,ParseSymbolsFromEmbeddedElfFile)151 TEST(read_elf, ParseSymbolsFromEmbeddedElfFile) {
152   std::map<std::string, ElfFileSymbol> symbols;
153   ElfStatus status;
154   std::string path = GetUrlInApk(APK_FILE, NATIVELIB_IN_APK);
155   auto elf = ElfFile::Open(GetTestData(path), &native_lib_build_id, &status);
156   ASSERT_EQ(status, ElfStatus::NO_ERROR);
157   ASSERT_EQ(ElfStatus::NO_SYMBOL_TABLE,
158             elf->ParseSymbols(std::bind(ParseSymbol, std::placeholders::_1, &symbols)));
159   CheckElfFileSymbols(symbols);
160 }
161 
162 // @CddTest = 6.1/C-0-2
TEST(read_elf,ParseSymbolFromMiniDebugInfoElfFile)163 TEST(read_elf, ParseSymbolFromMiniDebugInfoElfFile) {
164   std::map<std::string, ElfFileSymbol> symbols;
165   ElfStatus status;
166   auto elf = ElfFile::Open(GetTestData(ELF_FILE_WITH_MINI_DEBUG_INFO), &status);
167   ASSERT_EQ(ElfStatus::NO_ERROR, status);
168   ASSERT_EQ(ElfStatus::NO_ERROR,
169             elf->ParseSymbols(std::bind(ParseSymbol, std::placeholders::_1, &symbols)));
170   CheckFunctionSymbols(symbols);
171 }
172 
173 // @CddTest = 6.1/C-0-2
TEST(read_elf,arm_mapping_symbol)174 TEST(read_elf, arm_mapping_symbol) {
175   ASSERT_TRUE(IsArmMappingSymbol("$a"));
176   ASSERT_FALSE(IsArmMappingSymbol("$b"));
177   ASSERT_TRUE(IsArmMappingSymbol("$a.anything"));
178   ASSERT_FALSE(IsArmMappingSymbol("$a_no_dot"));
179 }
180 
181 // @CddTest = 6.1/C-0-2
TEST(read_elf,ElfFile_Open)182 TEST(read_elf, ElfFile_Open) {
183   auto IsValidElfPath = [](const std::string& path) {
184     ElfStatus status;
185     ElfFile::Open(path, &status);
186     return status;
187   };
188   ASSERT_NE(ElfStatus::NO_ERROR, IsValidElfPath("/dev/zero"));
189   TemporaryFile tmp_file;
190   ASSERT_EQ(ElfStatus::READ_FAILED, IsValidElfPath(tmp_file.path));
191   ASSERT_TRUE(android::base::WriteStringToFile("wrong format for elf", tmp_file.path));
192   ASSERT_EQ(ElfStatus::FILE_MALFORMED, IsValidElfPath(tmp_file.path));
193   ASSERT_EQ(ElfStatus::NO_ERROR, IsValidElfPath(GetTestData(ELF_FILE)));
194 }
195 
196 // @CddTest = 6.1/C-0-2
TEST(read_elf,check_symbol_for_plt_section)197 TEST(read_elf, check_symbol_for_plt_section) {
198   std::map<std::string, ElfFileSymbol> symbols;
199   ElfStatus status;
200   auto elf = ElfFile::Open(GetTestData(ELF_FILE), &status);
201   ASSERT_EQ(ElfStatus::NO_ERROR, status);
202   ASSERT_EQ(ElfStatus::NO_ERROR,
203             elf->ParseSymbols(std::bind(ParseSymbol, std::placeholders::_1, &symbols)));
204   ASSERT_NE(symbols.find("@plt"), symbols.end());
205 }
206 
207 // @CddTest = 6.1/C-0-2
TEST(read_elf,read_elf_with_broken_section_table)208 TEST(read_elf, read_elf_with_broken_section_table) {
209   std::string elf_path = GetTestData("libsgmainso-6.4.36.so");
210   std::map<std::string, ElfFileSymbol> symbols;
211   ElfStatus status;
212   auto elf = ElfFile::Open(elf_path, &status);
213   ASSERT_EQ(ElfStatus::NO_ERROR, status);
214   ASSERT_EQ(ElfStatus::NO_SYMBOL_TABLE,
215             elf->ParseSymbols(std::bind(ParseSymbol, std::placeholders::_1, &symbols)));
216 
217   BuildId build_id;
218   ASSERT_EQ(ElfStatus::NO_BUILD_ID, elf->GetBuildId(&build_id));
219 
220   uint64_t file_offset_of_min_vaddr;
221   uint64_t min_vaddr = elf->ReadMinExecutableVaddr(&file_offset_of_min_vaddr);
222   ASSERT_EQ(min_vaddr, 0u);
223   ASSERT_EQ(file_offset_of_min_vaddr, 0u);
224 }
225 
226 // @CddTest = 6.1/C-0-2
TEST(read_elf,ReadMinExecutableVaddr)227 TEST(read_elf, ReadMinExecutableVaddr) {
228   ElfStatus status;
229   auto elf = ElfFile::Open(GetTestData("libc.so"), &status);
230   ASSERT_EQ(status, ElfStatus::NO_ERROR);
231   uint64_t file_offset_of_min_vaddr;
232   uint64_t min_vaddr = elf->ReadMinExecutableVaddr(&file_offset_of_min_vaddr);
233   ASSERT_EQ(min_vaddr, 0x29000u);
234   ASSERT_EQ(file_offset_of_min_vaddr, 0x29000u);
235 }
236 
237 // @CddTest = 6.1/C-0-2
TEST(read_elf,NoUndefinedSymbol)238 TEST(read_elf, NoUndefinedSymbol) {
239   // Check if we read undefined symbols (like dlerror) from libc.so.
240   bool has_dlerror = false;
241   auto parse_symbol = [&](const ElfFileSymbol& symbol) {
242     if (symbol.name == "dlerror") {
243       has_dlerror = true;
244     }
245   };
246 
247   ElfStatus status;
248   auto elf = ElfFile::Open(GetTestData("libc.so"), &status);
249   ASSERT_EQ(status, ElfStatus::NO_ERROR);
250   ASSERT_EQ(ElfStatus::NO_ERROR, elf->ParseSymbols(parse_symbol));
251   ASSERT_FALSE(has_dlerror);
252 }
253 
254 // @CddTest = 6.1/C-0-2
TEST(read_elf,VaddrToOff)255 TEST(read_elf, VaddrToOff) {
256   auto elf = ElfFile::Open(GetTestData(ELF_FILE));
257   ASSERT_TRUE(elf != nullptr);
258   uint64_t off;
259   ASSERT_TRUE(elf->VaddrToOff(0x400200, &off));
260   ASSERT_EQ(off, 0x200);
261   ASSERT_FALSE(elf->VaddrToOff(0x300200, &off));
262   ASSERT_FALSE(elf->VaddrToOff(0x420000, &off));
263 }
264 
265 // @CddTest = 6.1/C-0-2
TEST(read_elf,GetSectionHeader)266 TEST(read_elf, GetSectionHeader) {
267   auto elf = ElfFile::Open(GetTestData(ELF_FILE));
268   ASSERT_TRUE(elf != nullptr);
269   std::vector<ElfSection> sections = elf->GetSectionHeader();
270   ASSERT_EQ(sections.size(), 30);
271   ASSERT_EQ(sections[13].name, ".text");
272   ASSERT_EQ(sections[13].vaddr, 0x400400);
273   ASSERT_EQ(sections[13].file_offset, 0x400);
274   ASSERT_EQ(sections[13].size, 0x1b2);
275 }
276