1 | // Copyright (c) 2012, Google Inc. |
2 | // All rights reserved. |
3 | // |
4 | // Redistribution and use in source and binary forms, with or without |
5 | // modification, are permitted provided that the following conditions are |
6 | // met: |
7 | // |
8 | // * Redistributions of source code must retain the above copyright |
9 | // notice, this list of conditions and the following disclaimer. |
10 | // * Redistributions in binary form must reproduce the above |
11 | // copyright notice, this list of conditions and the following disclaimer |
12 | // in the documentation and/or other materials provided with the |
13 | // distribution. |
14 | // * Neither the name of Google Inc. nor the names of its |
15 | // contributors may be used to endorse or promote products derived from |
16 | // this software without specific prior written permission. |
17 | // |
18 | // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
19 | // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
20 | // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
21 | // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
22 | // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
23 | // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
24 | // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
25 | // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
26 | // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
27 | // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
28 | // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
29 | // |
30 | // elfutils.h: Utilities for dealing with ELF files. |
31 | // |
32 | |
33 | #ifndef COMMON_LINUX_ELFUTILS_H_ |
34 | #define COMMON_LINUX_ELFUTILS_H_ |
35 | |
36 | #include <elf.h> |
37 | #include <link.h> |
38 | #include <stdint.h> |
39 | |
40 | #include "common/memory_allocator.h" |
41 | |
42 | namespace google_breakpad { |
43 | |
44 | // Traits classes so consumers can write templatized code to deal |
45 | // with specific ELF bits. |
46 | struct ElfClass32 { |
47 | typedef Elf32_Addr Addr; |
48 | typedef Elf32_Dyn Dyn; |
49 | typedef Elf32_Ehdr Ehdr; |
50 | typedef Elf32_Nhdr Nhdr; |
51 | typedef Elf32_Phdr Phdr; |
52 | typedef Elf32_Shdr Shdr; |
53 | typedef Elf32_Half Half; |
54 | typedef Elf32_Off Off; |
55 | typedef Elf32_Sym Sym; |
56 | typedef Elf32_Word Word; |
57 | |
58 | static const int kClass = ELFCLASS32; |
59 | static const uint16_t kMachine = EM_386; |
60 | static const size_t kAddrSize = sizeof(Elf32_Addr); |
61 | static constexpr const char* kMachineName = "x86" ; |
62 | }; |
63 | |
64 | struct ElfClass64 { |
65 | typedef Elf64_Addr Addr; |
66 | typedef Elf64_Dyn Dyn; |
67 | typedef Elf64_Ehdr Ehdr; |
68 | typedef Elf64_Nhdr Nhdr; |
69 | typedef Elf64_Phdr Phdr; |
70 | typedef Elf64_Shdr Shdr; |
71 | typedef Elf64_Half Half; |
72 | typedef Elf64_Off Off; |
73 | typedef Elf64_Sym Sym; |
74 | typedef Elf64_Word Word; |
75 | |
76 | static const int kClass = ELFCLASS64; |
77 | static const uint16_t kMachine = EM_X86_64; |
78 | static const size_t kAddrSize = sizeof(Elf64_Addr); |
79 | static constexpr const char* kMachineName = "x86_64" ; |
80 | }; |
81 | |
82 | bool IsValidElf(const void* ); |
83 | int ElfClass(const void* elf_base); |
84 | |
85 | // Attempt to find a section named |section_name| of type |section_type| |
86 | // in the ELF binary data at |elf_mapped_base|. On success, returns true |
87 | // and sets |*section_start| to point to the start of the section data, |
88 | // and |*section_size| to the size of the section's data. |
89 | bool FindElfSection(const void* elf_mapped_base, |
90 | const char* section_name, |
91 | uint32_t section_type, |
92 | const void** section_start, |
93 | size_t* section_size); |
94 | |
95 | // Internal helper method, exposed for convenience for callers |
96 | // that already have more info. |
97 | template<typename ElfClass> |
98 | const typename ElfClass::Shdr* |
99 | FindElfSectionByName(const char* name, |
100 | typename ElfClass::Word section_type, |
101 | const typename ElfClass::Shdr* sections, |
102 | const char* section_names, |
103 | const char* names_end, |
104 | int nsection); |
105 | |
106 | struct ElfSegment { |
107 | const void* start; |
108 | size_t size; |
109 | }; |
110 | |
111 | // Attempt to find all segments of type |segment_type| in the ELF |
112 | // binary data at |elf_mapped_base|. On success, returns true and fills |
113 | // |*segments| with a list of segments of the given type. |
114 | bool FindElfSegments(const void* elf_mapped_base, |
115 | uint32_t segment_type, |
116 | wasteful_vector<ElfSegment>* segments); |
117 | |
118 | // Convert an offset from an Elf header into a pointer to the mapped |
119 | // address in the current process. Takes an extra template parameter |
120 | // to specify the return type to avoid having to dynamic_cast the |
121 | // result. |
122 | template<typename ElfClass, typename T> |
123 | const T* |
124 | GetOffset(const typename ElfClass::Ehdr* , |
125 | typename ElfClass::Off offset); |
126 | |
127 | // Read the value of DT_SONAME from the elf file mapped at |elf_base|. Returns |
128 | // true and fills |soname| with the result if found. |
129 | bool ElfFileSoNameFromMappedFile(const void* elf_base, |
130 | char* soname, |
131 | size_t soname_size); |
132 | |
133 | } // namespace google_breakpad |
134 | |
135 | #endif // COMMON_LINUX_ELFUTILS_H_ |
136 | |