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 #include <android-base/test_utils.h>
25 
26 #include "get_test_data.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 TEST(read_elf, GetBuildIdFromNoteSection) {
34   BuildId build_id;
35   std::vector<char> data;
36   // Fail to read build id for no data.
37   ASSERT_FALSE(GetBuildIdFromNoteSection(data.data(), 0, &build_id));
38 
39   // Read build id from data starting from different alignment addresses.
40   char build_id_data[20];
41   for (int i = 0; i < 20; ++i) {
42     build_id_data[i] = i;
43   }
44   BuildId expected_build_id(build_id_data, 20);
45   data.resize(100, '\0');
46 
47   for (size_t alignment = 0; alignment <= 3; ++alignment) {
48     char* start = data.data() + alignment;
49     char* p = start;
50     uint32_t type = NT_GNU_BUILD_ID;
51     uint32_t namesz = 4;
52     uint32_t descsz = 20;
53     MoveToBinaryFormat(namesz, p);
54     MoveToBinaryFormat(descsz, p);
55     MoveToBinaryFormat(type, p);
56     MoveToBinaryFormat(ELF_NOTE_GNU, 4, p);
57     MoveToBinaryFormat(build_id_data, 20, p);
58     ASSERT_TRUE(GetBuildIdFromNoteSection(start, p - start, &build_id));
59     ASSERT_TRUE(build_id == expected_build_id);
60   }
61 }
62 
63 TEST(read_elf, GetBuildIdFromElfFile) {
64   BuildId build_id;
65   ASSERT_EQ(ElfStatus::NO_ERROR, GetBuildIdFromElfFile(GetTestData(ELF_FILE), &build_id));
66   ASSERT_EQ(build_id, BuildId(elf_file_build_id));
67 }
68 
69 TEST(read_elf, GetBuildIdFromEmbeddedElfFile) {
70   BuildId build_id;
71   ASSERT_EQ(ElfStatus::NO_ERROR, GetBuildIdFromEmbeddedElfFile(GetTestData(APK_FILE), NATIVELIB_OFFSET_IN_APK,
72                                             NATIVELIB_SIZE_IN_APK, &build_id));
73   ASSERT_EQ(build_id, native_lib_build_id);
74 }
75 
76 void ParseSymbol(const ElfFileSymbol& symbol, std::map<std::string, ElfFileSymbol>* symbols) {
77   (*symbols)[symbol.name] = symbol;
78 }
79 
80 static void CheckGlobalVariableSymbols(const std::map<std::string, ElfFileSymbol>& symbols) {
81   auto pos = symbols.find("GlobalVar");
82   ASSERT_NE(pos, symbols.end());
83   ASSERT_FALSE(pos->second.is_func);
84 }
85 
86 static void CheckFunctionSymbols(const std::map<std::string, ElfFileSymbol>& symbols) {
87   auto pos = symbols.find("GlobalFunc");
88   ASSERT_NE(pos, symbols.end());
89   ASSERT_TRUE(pos->second.is_func);
90   ASSERT_TRUE(pos->second.is_in_text_section);
91 }
92 
93 void CheckElfFileSymbols(const std::map<std::string, ElfFileSymbol>& symbols) {
94   CheckGlobalVariableSymbols(symbols);
95   CheckFunctionSymbols(symbols);
96 }
97 
98 TEST(read_elf, parse_symbols_from_elf_file_with_correct_build_id) {
99   std::map<std::string, ElfFileSymbol> symbols;
100   ASSERT_EQ(ElfStatus::NO_ERROR, ParseSymbolsFromElfFile(GetTestData(ELF_FILE), elf_file_build_id,
101                                       std::bind(ParseSymbol, std::placeholders::_1, &symbols)));
102   CheckElfFileSymbols(symbols);
103 }
104 
105 TEST(read_elf, parse_symbols_from_elf_file_without_build_id) {
106   std::map<std::string, ElfFileSymbol> symbols;
107   ASSERT_EQ(ElfStatus::NO_ERROR, ParseSymbolsFromElfFile(GetTestData(ELF_FILE), BuildId(),
108                                       std::bind(ParseSymbol, std::placeholders::_1, &symbols)));
109   CheckElfFileSymbols(symbols);
110 }
111 
112 TEST(read_elf, parse_symbols_from_elf_file_with_wrong_build_id) {
113   BuildId build_id("01010101010101010101");
114   std::map<std::string, ElfFileSymbol> symbols;
115   ASSERT_EQ(ElfStatus::BUILD_ID_MISMATCH, ParseSymbolsFromElfFile(GetTestData(ELF_FILE), build_id,
116                                        std::bind(ParseSymbol, std::placeholders::_1, &symbols)));
117 }
118 
119 TEST(read_elf, ParseSymbolsFromEmbeddedElfFile) {
120   std::map<std::string, ElfFileSymbol> symbols;
121   ASSERT_EQ(ElfStatus::NO_SYMBOL_TABLE, ParseSymbolsFromEmbeddedElfFile(GetTestData(APK_FILE), NATIVELIB_OFFSET_IN_APK,
122                                               NATIVELIB_SIZE_IN_APK, native_lib_build_id,
123                                               std::bind(ParseSymbol, std::placeholders::_1, &symbols)));
124   CheckElfFileSymbols(symbols);
125 }
126 
127 TEST(read_elf, ParseSymbolFromMiniDebugInfoElfFile) {
128   std::map<std::string, ElfFileSymbol> symbols;
129   ASSERT_EQ(ElfStatus::NO_ERROR, ParseSymbolsFromElfFile(GetTestData(ELF_FILE_WITH_MINI_DEBUG_INFO), BuildId(),
130                                       std::bind(ParseSymbol, std::placeholders::_1, &symbols)));
131   CheckFunctionSymbols(symbols);
132 }
133 
134 TEST(read_elf, arm_mapping_symbol) {
135   ASSERT_TRUE(IsArmMappingSymbol("$a"));
136   ASSERT_FALSE(IsArmMappingSymbol("$b"));
137   ASSERT_TRUE(IsArmMappingSymbol("$a.anything"));
138   ASSERT_FALSE(IsArmMappingSymbol("$a_no_dot"));
139 }
140 
141 TEST(read_elf, IsValidElfPath) {
142   ASSERT_NE(ElfStatus::NO_ERROR, IsValidElfPath("/dev/zero"));
143   TemporaryFile tmp_file;
144   ASSERT_EQ(ElfStatus::READ_FAILED, IsValidElfPath(tmp_file.path));
145   ASSERT_TRUE(android::base::WriteStringToFile("wrong format for elf", tmp_file.path));
146   ASSERT_EQ(ElfStatus::FILE_MALFORMED, IsValidElfPath(tmp_file.path));
147   ASSERT_EQ(ElfStatus::NO_ERROR, IsValidElfPath(GetTestData(ELF_FILE)));
148 }
149 
150 TEST(read_elf, check_symbol_for_plt_section) {
151   std::map<std::string, ElfFileSymbol> symbols;
152   ASSERT_EQ(ElfStatus::NO_ERROR, ParseSymbolsFromElfFile(GetTestData(ELF_FILE), BuildId(),
153                                       std::bind(ParseSymbol, std::placeholders::_1, &symbols)));
154   ASSERT_NE(symbols.find("@plt"), symbols.end());
155 }
156 
157 TEST(read_elf, read_elf_with_broken_section_table) {
158   std::map<std::string, ElfFileSymbol> symbols;
159   ASSERT_EQ(ElfStatus::NO_SYMBOL_TABLE,
160             ParseSymbolsFromElfFile(GetTestData("libsgmainso-6.4.36.so"), BuildId(),
161                                     std::bind(ParseSymbol, std::placeholders::_1, &symbols)));
162 }
163