1 /*
2 * Copyright 2011-2012, 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 "librsloader.h"
18
19 #include "ELFObject.h"
20 #include "ELFSectionSymTab.h"
21 #include "ELFSymbol.h"
22
23 #include "utils/serialize.h"
24
25 #define LOG_TAG "bcc"
26 #include "cutils/log.h"
27
28 #include <llvm/Support/ELF.h>
29
30 #if defined(__LP64__) || defined(__x86_64__)
wrap(ELFObject<64> * object)31 static inline RSExecRef wrap(ELFObject<64> *object) {
32 return reinterpret_cast<RSExecRef>(object);
33 }
34 #else
wrap(ELFObject<32> * object)35 static inline RSExecRef wrap(ELFObject<32> *object) {
36 return reinterpret_cast<RSExecRef>(object);
37 }
38 #endif
39
40 #if defined(__LP64__) || defined(__x86_64__)
unwrap(RSExecRef object)41 static inline ELFObject<64> *unwrap(RSExecRef object) {
42 return reinterpret_cast<ELFObject<64> *>(object);
43 }
44 #else
unwrap(RSExecRef object)45 static inline ELFObject<32> *unwrap(RSExecRef object) {
46 return reinterpret_cast<ELFObject<32> *>(object);
47 }
48 #endif
49
rsloaderCreateExec(unsigned char const * buf,size_t buf_size,RSFindSymbolFn find_symbol,void * find_symbol_context)50 extern "C" RSExecRef rsloaderCreateExec(unsigned char const *buf,
51 size_t buf_size,
52 RSFindSymbolFn find_symbol,
53 void *find_symbol_context) {
54 RSExecRef object = rsloaderLoadExecutable(buf, buf_size);
55 if (!object) {
56 return NULL;
57 }
58
59 if (!rsloaderRelocateExecutable(object, find_symbol, find_symbol_context)) {
60 rsloaderDisposeExec(object);
61 return NULL;
62 }
63
64 return object;
65 }
66
rsloaderLoadExecutable(unsigned char const * buf,size_t buf_size)67 extern "C" RSExecRef rsloaderLoadExecutable(unsigned char const *buf,
68 size_t buf_size) {
69 ArchiveReaderLE AR(buf, buf_size);
70
71 #if defined(__LP64__) || defined(__x86_64__)
72 std::unique_ptr<ELFObject<64> > object(ELFObject<64>::read(AR));
73 #else
74 std::unique_ptr<ELFObject<32> > object(ELFObject<32>::read(AR));
75 #endif
76 if (!object) {
77 ALOGE("Unable to load the ELF object.");
78 return NULL;
79 }
80
81 return wrap(object.release());
82 }
83
rsloaderRelocateExecutable(RSExecRef object_,RSFindSymbolFn find_symbol,void * find_symbol_context)84 extern "C" int rsloaderRelocateExecutable(RSExecRef object_,
85 RSFindSymbolFn find_symbol,
86 void *find_symbol_context) {
87 #if defined(__LP64__) || defined(__x86_64__)
88 ELFObject<64>* object = unwrap(object_);
89 #else
90 ELFObject<32>* object = unwrap(object_);
91 #endif
92 object->relocate(find_symbol, find_symbol_context);
93 return (object->getMissingSymbols() == 0);
94 }
95
rsloaderUpdateSectionHeaders(RSExecRef object_,unsigned char * buf)96 extern "C" void rsloaderUpdateSectionHeaders(RSExecRef object_,
97 unsigned char *buf) {
98 #if defined(__LP64__) || defined(__x86_64__)
99 ELFObject<64> *object = unwrap(object_);
100 #else
101 ELFObject<32> *object = unwrap(object_);
102 #endif
103
104 // Remap the section header addresses to match the loaded code
105 #if defined(__LP64__) || defined(__x86_64__)
106 llvm::ELF::Elf64_Ehdr* header = reinterpret_cast<llvm::ELF::Elf64_Ehdr*>(buf);
107 #else
108 llvm::ELF::Elf32_Ehdr* header = reinterpret_cast<llvm::ELF::Elf32_Ehdr*>(buf);
109 #endif
110
111 #if defined(__LP64__) || defined(__x86_64__)
112 llvm::ELF::Elf64_Shdr* shtab =
113 reinterpret_cast<llvm::ELF::Elf64_Shdr*>(buf + header->e_shoff);
114 #else
115 llvm::ELF::Elf32_Shdr* shtab =
116 reinterpret_cast<llvm::ELF::Elf32_Shdr*>(buf + header->e_shoff);
117 #endif
118
119 for (int i = 0; i < header->e_shnum; i++) {
120 if (shtab[i].sh_flags & SHF_ALLOC) {
121 #if defined(__LP64__) || defined(__x86_64__)
122 ELFSectionBits<64>* bits =
123 static_cast<ELFSectionBits<64>*>(object->getSectionByIndex(i));
124 #else
125 ELFSectionBits<32>* bits =
126 static_cast<ELFSectionBits<32>*>(object->getSectionByIndex(i));
127 #endif
128 if (bits) {
129 const unsigned char* addr = bits->getBuffer();
130 #if defined(__LP64__) || defined(__x86_64__)
131 shtab[i].sh_addr = reinterpret_cast<llvm::ELF::Elf64_Addr>(addr);
132 #else
133 shtab[i].sh_addr = reinterpret_cast<llvm::ELF::Elf32_Addr>(addr);
134 #endif
135 }
136 }
137 }
138 }
139
rsloaderDisposeExec(RSExecRef object)140 extern "C" void rsloaderDisposeExec(RSExecRef object) {
141 delete unwrap(object);
142 }
143
rsloaderGetSymbolAddress(RSExecRef object_,char const * name)144 extern "C" void *rsloaderGetSymbolAddress(RSExecRef object_,
145 char const *name) {
146 #if defined(__LP64__) || defined(__x86_64__)
147 ELFObject<64> *object = unwrap(object_);
148
149 ELFSectionSymTab<64> *symtab =
150 static_cast<ELFSectionSymTab<64> *>(object->getSectionByName(".symtab"));
151 #else
152 ELFObject<32> *object = unwrap(object_);
153
154 ELFSectionSymTab<32> *symtab =
155 static_cast<ELFSectionSymTab<32> *>(object->getSectionByName(".symtab"));
156 #endif
157
158 if (!symtab) {
159 return NULL;
160 }
161
162 #if defined(__LP64__) || defined(__x86_64__)
163 ELFSymbol<64> *symbol = symtab->getByName(name);
164 #else
165 ELFSymbol<32> *symbol = symtab->getByName(name);
166 #endif
167
168 if (!symbol) {
169 ALOGV("Symbol not found: %s\n", name);
170 return NULL;
171 }
172
173 int machine = object->getHeader()->getMachine();
174
175 return symbol->getAddress(machine, false);
176 }
177
rsloaderGetSymbolSize(RSExecRef object_,char const * name)178 extern "C" size_t rsloaderGetSymbolSize(RSExecRef object_, char const *name) {
179 #if defined(__LP64__) || defined(__x86_64__)
180 ELFObject<64> *object = unwrap(object_);
181
182 ELFSectionSymTab<64> *symtab =
183 static_cast<ELFSectionSymTab<64> *>(object->getSectionByName(".symtab"));
184 #else
185 ELFObject<32> *object = unwrap(object_);
186
187 ELFSectionSymTab<32> *symtab =
188 static_cast<ELFSectionSymTab<32> *>(object->getSectionByName(".symtab"));
189 #endif
190 if (!symtab) {
191 return 0;
192 }
193
194 #if defined(__LP64__) || defined(__x86_64__)
195 ELFSymbol<64> *symbol = symtab->getByName(name);
196 #else
197 ELFSymbol<32> *symbol = symtab->getByName(name);
198 #endif
199
200 if (!symbol) {
201 ALOGV("Symbol not found: %s\n", name);
202 return 0;
203 }
204
205 return (size_t)symbol->getSize();
206 }
207
rsloaderGetFuncCount(RSExecRef object)208 extern "C" size_t rsloaderGetFuncCount(RSExecRef object) {
209 #if defined(__LP64__) || defined(__x86_64__)
210 ELFSectionSymTab<64> *symtab = static_cast<ELFSectionSymTab<64> *>(
211 #else
212 ELFSectionSymTab<32> *symtab = static_cast<ELFSectionSymTab<32> *>(
213 #endif
214 unwrap(object)->getSectionByName(".symtab"));
215
216 if (!symtab) {
217 return 0;
218 }
219
220 return symtab->getFuncCount();
221 }
222
rsloaderGetFuncNameList(RSExecRef object,size_t size,char const ** list)223 extern "C" void rsloaderGetFuncNameList(RSExecRef object,
224 size_t size,
225 char const **list) {
226 #if defined(__LP64__) || defined(__x86_64__)
227 ELFSectionSymTab<64> *symtab = static_cast<ELFSectionSymTab<64> *>(
228 #else
229 ELFSectionSymTab<32> *symtab = static_cast<ELFSectionSymTab<32> *>(
230 #endif
231 unwrap(object)->getSectionByName(".symtab"));
232
233 if (symtab) {
234 symtab->getFuncNameList(size, list);
235 }
236 }
237