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_RUNTIME_ELF_UTILS_H_
18 #define ART_RUNTIME_ELF_UTILS_H_
19
20 #include <sys/cdefs.h>
21
22 // Explicitly include our own elf.h to avoid Linux and other dependencies.
23 #include "./elf.h"
24
25 #include "base/logging.h"
26
27 namespace art {
28
29 // Architecture dependent flags for the ELF header.
30 #define EF_ARM_EABI_VER5 0x05000000
31 #define EF_MIPS_ABI_O32 0x00001000
32 #define EF_MIPS_ARCH_32R2 0x70000000
33 #define EF_MIPS_ARCH_32R6 0x90000000
34 #define EF_MIPS_ARCH_64R6 0xa0000000
35
36 #define EI_ABIVERSION 8
37 #define EM_ARM 40
38 #define EF_MIPS_NOREORDER 1
39 #define EF_MIPS_PIC 2
40 #define EF_MIPS_CPIC 4
41 #define STV_DEFAULT 0
42
43 #define EM_AARCH64 183
44
45 #define DT_BIND_NOW 24
46 #define DT_INIT_ARRAY 25
47 #define DT_FINI_ARRAY 26
48 #define DT_INIT_ARRAYSZ 27
49 #define DT_FINI_ARRAYSZ 28
50 #define DT_RUNPATH 29
51 #define DT_FLAGS 30
52
53 /* MIPS dependent d_tag field for Elf32_Dyn. */
54 #define DT_MIPS_RLD_VERSION 0x70000001 /* Runtime Linker Interface ID */
55 #define DT_MIPS_TIME_STAMP 0x70000002 /* Timestamp */
56 #define DT_MIPS_ICHECKSUM 0x70000003 /* Cksum of ext. str. and com. sizes */
57 #define DT_MIPS_IVERSION 0x70000004 /* Version string (string tbl index) */
58 #define DT_MIPS_FLAGS 0x70000005 /* Flags */
59 #define DT_MIPS_BASE_ADDRESS 0x70000006 /* Segment base address */
60 #define DT_MIPS_CONFLICT 0x70000008 /* Adr of .conflict section */
61 #define DT_MIPS_LIBLIST 0x70000009 /* Address of .liblist section */
62 #define DT_MIPS_LOCAL_GOTNO 0x7000000a /* Number of local .GOT entries */
63 #define DT_MIPS_CONFLICTNO 0x7000000b /* Number of .conflict entries */
64 #define DT_MIPS_LIBLISTNO 0x70000010 /* Number of .liblist entries */
65 #define DT_MIPS_SYMTABNO 0x70000011 /* Number of .dynsym entries */
66 #define DT_MIPS_UNREFEXTNO 0x70000012 /* First external DYNSYM */
67 #define DT_MIPS_GOTSYM 0x70000013 /* First GOT entry in .dynsym */
68 #define DT_MIPS_HIPAGENO 0x70000014 /* Number of GOT page table entries */
69 #define DT_MIPS_RLD_MAP 0x70000016 /* Address of debug map pointer */
70
71 // Patching section type
72 #define SHT_OAT_PATCH SHT_LOUSER
73
SetBindingAndType(Elf32_Sym * sym,unsigned char b,unsigned char t)74 static inline void SetBindingAndType(Elf32_Sym* sym, unsigned char b, unsigned char t) {
75 sym->st_info = (b << 4) + (t & 0x0f);
76 }
77
IsDynamicSectionPointer(Elf32_Word d_tag,Elf32_Word e_machine)78 static inline bool IsDynamicSectionPointer(Elf32_Word d_tag, Elf32_Word e_machine) {
79 switch (d_tag) {
80 // case 1: well known d_tag values that imply Elf32_Dyn.d_un contains an address in d_ptr
81 case DT_PLTGOT:
82 case DT_HASH:
83 case DT_STRTAB:
84 case DT_SYMTAB:
85 case DT_RELA:
86 case DT_INIT:
87 case DT_FINI:
88 case DT_REL:
89 case DT_DEBUG:
90 case DT_JMPREL: {
91 return true;
92 }
93 // d_val or ignored values
94 case DT_NULL:
95 case DT_NEEDED:
96 case DT_PLTRELSZ:
97 case DT_RELASZ:
98 case DT_RELAENT:
99 case DT_STRSZ:
100 case DT_SYMENT:
101 case DT_SONAME:
102 case DT_RPATH:
103 case DT_SYMBOLIC:
104 case DT_RELSZ:
105 case DT_RELENT:
106 case DT_PLTREL:
107 case DT_TEXTREL:
108 case DT_BIND_NOW:
109 case DT_INIT_ARRAYSZ:
110 case DT_FINI_ARRAYSZ:
111 case DT_RUNPATH:
112 case DT_FLAGS: {
113 return false;
114 }
115 // boundary values that should not be used
116 case DT_ENCODING:
117 case DT_LOOS:
118 case DT_HIOS:
119 case DT_LOPROC:
120 case DT_HIPROC: {
121 LOG(FATAL) << "Illegal d_tag value 0x" << std::hex << d_tag;
122 return false;
123 }
124 default: {
125 // case 2: "regular" DT_* ranges where even d_tag values imply an address in d_ptr
126 if ((DT_ENCODING < d_tag && d_tag < DT_LOOS)
127 || (DT_LOOS < d_tag && d_tag < DT_HIOS)
128 || (DT_LOPROC < d_tag && d_tag < DT_HIPROC)) {
129 // Special case for MIPS which breaks the regular rules between DT_LOPROC and DT_HIPROC
130 if (e_machine == EM_MIPS) {
131 switch (d_tag) {
132 case DT_MIPS_RLD_VERSION:
133 case DT_MIPS_TIME_STAMP:
134 case DT_MIPS_ICHECKSUM:
135 case DT_MIPS_IVERSION:
136 case DT_MIPS_FLAGS:
137 case DT_MIPS_LOCAL_GOTNO:
138 case DT_MIPS_CONFLICTNO:
139 case DT_MIPS_LIBLISTNO:
140 case DT_MIPS_SYMTABNO:
141 case DT_MIPS_UNREFEXTNO:
142 case DT_MIPS_GOTSYM:
143 case DT_MIPS_HIPAGENO: {
144 return false;
145 }
146 case DT_MIPS_BASE_ADDRESS:
147 case DT_MIPS_CONFLICT:
148 case DT_MIPS_LIBLIST:
149 case DT_MIPS_RLD_MAP: {
150 return true;
151 }
152 default: {
153 LOG(FATAL) << "Unknown MIPS d_tag value 0x" << std::hex << d_tag;
154 return false;
155 }
156 }
157 } else if ((d_tag % 2) == 0) {
158 return true;
159 } else {
160 return false;
161 }
162 } else {
163 LOG(FATAL) << "Unknown d_tag value 0x" << std::hex << d_tag;
164 return false;
165 }
166 }
167 }
168 }
169
170 } // namespace art
171
172 #endif // ART_RUNTIME_ELF_UTILS_H_
173