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 #if !defined(STV_DEFAULT)
69 #define STV_DEFAULT 0
70 #endif
71
72 #define EM_AARCH64 183
73
74 #ifndef EM_RISCV
75 #define EM_RISCV 243
76 #endif
77
78 #ifndef EF_RISCV_RVC
79 #define EF_RISCV_RVC 0x1
80 #define EF_RISCV_FLOAT_ABI_DOUBLE 0x4
81 #endif
82
83 #define DT_BIND_NOW 24
84 #define DT_INIT_ARRAY 25
85 #define DT_FINI_ARRAY 26
86 #define DT_INIT_ARRAYSZ 27
87 #define DT_FINI_ARRAYSZ 28
88 #define DT_RUNPATH 29
89 #define DT_FLAGS 30
90
91 // Patching section type
92 #define SHT_OAT_PATCH SHT_LOUSER
93
SetBindingAndType(Elf32_Sym * sym,unsigned char b,unsigned char t)94 static inline void SetBindingAndType(Elf32_Sym* sym, unsigned char b, unsigned char t) {
95 sym->st_info = (b << 4) + (t & 0x0f);
96 }
97
IsDynamicSectionPointer(Elf32_Word d_tag,Elf32_Word e_machine ATTRIBUTE_UNUSED)98 static inline bool IsDynamicSectionPointer(Elf32_Word d_tag,
99 Elf32_Word e_machine ATTRIBUTE_UNUSED) {
100 // TODO: Remove the `e_machine` parameter from API (not needed after Mips target was removed).
101 switch (d_tag) {
102 // case 1: well known d_tag values that imply Elf32_Dyn.d_un contains an address in d_ptr
103 case DT_PLTGOT:
104 case DT_HASH:
105 case DT_STRTAB:
106 case DT_SYMTAB:
107 case DT_RELA:
108 case DT_INIT:
109 case DT_FINI:
110 case DT_REL:
111 case DT_DEBUG:
112 case DT_JMPREL: {
113 return true;
114 }
115 // d_val or ignored values
116 case DT_NULL:
117 case DT_NEEDED:
118 case DT_PLTRELSZ:
119 case DT_RELASZ:
120 case DT_RELAENT:
121 case DT_STRSZ:
122 case DT_SYMENT:
123 case DT_SONAME:
124 case DT_RPATH:
125 case DT_SYMBOLIC:
126 case DT_RELSZ:
127 case DT_RELENT:
128 case DT_PLTREL:
129 case DT_TEXTREL:
130 case DT_BIND_NOW:
131 case DT_INIT_ARRAYSZ:
132 case DT_FINI_ARRAYSZ:
133 case DT_RUNPATH:
134 case DT_FLAGS: {
135 return false;
136 }
137 // boundary values that should not be used
138 case DT_ENCODING:
139 case DT_LOOS:
140 case DT_HIOS:
141 case DT_LOPROC:
142 case DT_HIPROC: {
143 LOG(FATAL) << "Illegal d_tag value 0x" << std::hex << d_tag;
144 return false;
145 }
146 default: {
147 // case 2: "regular" DT_* ranges where even d_tag values imply an address in d_ptr
148 if ((DT_ENCODING < d_tag && d_tag < DT_LOOS)
149 || (DT_LOOS < d_tag && d_tag < DT_HIOS)
150 || (DT_LOPROC < d_tag && d_tag < DT_HIPROC)) {
151 if ((d_tag % 2) == 0) {
152 return true;
153 } else {
154 return false;
155 }
156 } else {
157 LOG(FATAL) << "Unknown d_tag value 0x" << std::hex << d_tag;
158 return false;
159 }
160 }
161 }
162 }
163
164 } // namespace art
165
166 #endif // ART_LIBELFFILE_ELF_ELF_UTILS_H_
167