1 /*
2 * Copyright (C) 2014 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 #ifndef ART_LIBELFFILE_ELF_ELF_UTILS_H_
18 #define ART_LIBELFFILE_ELF_ELF_UTILS_H_
19
20 #include <elf.h>
21
22 #include <sys/cdefs.h>
23
24 #include <android-base/logging.h>
25
26 namespace art {
27
28 struct ElfTypes32 {
29 using Addr = Elf32_Addr;
30 using Off = Elf32_Off;
31 using Half = Elf32_Half;
32 using Word = Elf32_Word;
33 using Sword = Elf32_Sword;
34 using Ehdr = Elf32_Ehdr;
35 using Shdr = Elf32_Shdr;
36 using Sym = Elf32_Sym;
37 using Rel = Elf32_Rel;
38 using Rela = Elf32_Rela;
39 using Phdr = Elf32_Phdr;
40 using Dyn = Elf32_Dyn;
41 };
42
43 struct ElfTypes64 {
44 using Addr = Elf64_Addr;
45 using Off = Elf64_Off;
46 using Half = Elf64_Half;
47 using Word = Elf64_Word;
48 using Sword = Elf64_Sword;
49 using Xword = Elf64_Xword;
50 using Sxword = Elf64_Sxword;
51 using Ehdr = Elf64_Ehdr;
52 using Shdr = Elf64_Shdr;
53 using Sym = Elf64_Sym;
54 using Rel = Elf64_Rel;
55 using Rela = Elf64_Rela;
56 using Phdr = Elf64_Phdr;
57 using Dyn = Elf64_Dyn;
58 };
59
60 #define ELF_ST_BIND(x) ((x) >> 4)
61 #define ELF_ST_TYPE(x) ((x) & 0xf)
62
63 // Architecture dependent flags for the ELF header.
64 #define EF_ARM_EABI_VER5 0x05000000
65
66 #define EI_ABIVERSION 8
67 #define EM_ARM 40
68 #define STV_DEFAULT 0
69
70 #define EM_AARCH64 183
71
72 #define DT_BIND_NOW 24
73 #define DT_INIT_ARRAY 25
74 #define DT_FINI_ARRAY 26
75 #define DT_INIT_ARRAYSZ 27
76 #define DT_FINI_ARRAYSZ 28
77 #define DT_RUNPATH 29
78 #define DT_FLAGS 30
79
80 // Patching section type
81 #define SHT_OAT_PATCH SHT_LOUSER
82
SetBindingAndType(Elf32_Sym * sym,unsigned char b,unsigned char t)83 static inline void SetBindingAndType(Elf32_Sym* sym, unsigned char b, unsigned char t) {
84 sym->st_info = (b << 4) + (t & 0x0f);
85 }
86
IsDynamicSectionPointer(Elf32_Word d_tag,Elf32_Word e_machine ATTRIBUTE_UNUSED)87 static inline bool IsDynamicSectionPointer(Elf32_Word d_tag,
88 Elf32_Word e_machine ATTRIBUTE_UNUSED) {
89 // TODO: Remove the `e_machine` parameter from API (not needed after Mips target was removed).
90 switch (d_tag) {
91 // case 1: well known d_tag values that imply Elf32_Dyn.d_un contains an address in d_ptr
92 case DT_PLTGOT:
93 case DT_HASH:
94 case DT_STRTAB:
95 case DT_SYMTAB:
96 case DT_RELA:
97 case DT_INIT:
98 case DT_FINI:
99 case DT_REL:
100 case DT_DEBUG:
101 case DT_JMPREL: {
102 return true;
103 }
104 // d_val or ignored values
105 case DT_NULL:
106 case DT_NEEDED:
107 case DT_PLTRELSZ:
108 case DT_RELASZ:
109 case DT_RELAENT:
110 case DT_STRSZ:
111 case DT_SYMENT:
112 case DT_SONAME:
113 case DT_RPATH:
114 case DT_SYMBOLIC:
115 case DT_RELSZ:
116 case DT_RELENT:
117 case DT_PLTREL:
118 case DT_TEXTREL:
119 case DT_BIND_NOW:
120 case DT_INIT_ARRAYSZ:
121 case DT_FINI_ARRAYSZ:
122 case DT_RUNPATH:
123 case DT_FLAGS: {
124 return false;
125 }
126 // boundary values that should not be used
127 case DT_ENCODING:
128 case DT_LOOS:
129 case DT_HIOS:
130 case DT_LOPROC:
131 case DT_HIPROC: {
132 LOG(FATAL) << "Illegal d_tag value 0x" << std::hex << d_tag;
133 return false;
134 }
135 default: {
136 // case 2: "regular" DT_* ranges where even d_tag values imply an address in d_ptr
137 if ((DT_ENCODING < d_tag && d_tag < DT_LOOS)
138 || (DT_LOOS < d_tag && d_tag < DT_HIOS)
139 || (DT_LOPROC < d_tag && d_tag < DT_HIPROC)) {
140 if ((d_tag % 2) == 0) {
141 return true;
142 } else {
143 return false;
144 }
145 } else {
146 LOG(FATAL) << "Unknown d_tag value 0x" << std::hex << d_tag;
147 return false;
148 }
149 }
150 }
151 }
152
153 } // namespace art
154
155 #endif // ART_LIBELFFILE_ELF_ELF_UTILS_H_
156