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bc644c6c ILT |
1 | // binary.cc -- binary input files for gold |
2 | ||
b3adc24a | 3 | // Copyright (C) 2008-2020 Free Software Foundation, Inc. |
bc644c6c ILT |
4 | // Written by Ian Lance Taylor <iant@google.com>. |
5 | ||
6 | // This file is part of gold. | |
7 | ||
8 | // This program is free software; you can redistribute it and/or modify | |
9 | // it under the terms of the GNU General Public License as published by | |
10 | // the Free Software Foundation; either version 3 of the License, or | |
11 | // (at your option) any later version. | |
12 | ||
13 | // This program is distributed in the hope that it will be useful, | |
14 | // but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | // GNU General Public License for more details. | |
17 | ||
18 | // You should have received a copy of the GNU General Public License | |
19 | // along with this program; if not, write to the Free Software | |
20 | // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, | |
21 | // MA 02110-1301, USA. | |
22 | ||
23 | #include "gold.h" | |
24 | ||
25 | #include <cerrno> | |
26 | #include <cstring> | |
bc644c6c ILT |
27 | |
28 | #include "elfcpp.h" | |
29 | #include "stringpool.h" | |
30 | #include "fileread.h" | |
31 | #include "output.h" | |
32 | #include "binary.h" | |
33 | ||
95c29a83 RM |
34 | // safe-ctype.h interferes with macros defined by the system <ctype.h>. |
35 | // Some C++ system headers might include <ctype.h> and rely on its macro | |
36 | // definitions being intact. So make sure that safe-ctype.h is included | |
37 | // only after any C++ system headers, whether directly here (above) or via | |
38 | // other local header files (e.g. #include <string> in "binary.h"). | |
39 | #include "safe-ctype.h" | |
40 | ||
bc644c6c ILT |
41 | // Support for reading binary files as input. These become blobs in |
42 | // the final output. These files are treated as though they have a | |
43 | // single .data section and define three symbols: | |
602b464e | 44 | // _binary_FILENAME_start, _binary_FILENAME_end, _binary_FILENAME_size. |
bc644c6c ILT |
45 | // The FILENAME is the name of the input file, with any |
46 | // non-alphanumeric character changed to an underscore. | |
47 | ||
48 | // We implement this by creating an ELF file in memory. | |
49 | ||
50 | namespace gold | |
51 | { | |
52 | ||
53 | // class Binary_to_elf. | |
54 | ||
55 | Binary_to_elf::Binary_to_elf(elfcpp::EM machine, int size, bool big_endian, | |
56 | const std::string& filename) | |
57 | : elf_machine_(machine), size_(size), big_endian_(big_endian), | |
58 | filename_(filename), data_(NULL), filesize_(0) | |
59 | { | |
60 | } | |
61 | ||
62 | Binary_to_elf::~Binary_to_elf() | |
63 | { | |
64 | if (this->data_ != NULL) | |
65 | delete[] this->data_; | |
66 | } | |
67 | ||
68 | // Given FILENAME, create a buffer which looks like an ELF file with | |
69 | // the contents of FILENAME as the contents of the only section. The | |
70 | // TASK parameters is mainly for debugging, and records who holds | |
71 | // locks. | |
72 | ||
73 | bool | |
74 | Binary_to_elf::convert(const Task* task) | |
75 | { | |
76 | if (this->size_ == 32) | |
77 | { | |
78 | if (!this->big_endian_) | |
79 | { | |
80 | #ifdef HAVE_TARGET_32_LITTLE | |
81 | return this->sized_convert<32, false>(task); | |
82 | #else | |
83 | gold_unreachable(); | |
84 | #endif | |
85 | } | |
86 | else | |
87 | { | |
88 | #ifdef HAVE_TARGET_32_BIG | |
89 | return this->sized_convert<32, true>(task); | |
90 | #else | |
91 | gold_unreachable(); | |
92 | #endif | |
93 | } | |
94 | } | |
95 | else if (this->size_ == 64) | |
96 | { | |
97 | if (!this->big_endian_) | |
98 | { | |
99 | #ifdef HAVE_TARGET_64_LITTLE | |
100 | return this->sized_convert<64, false>(task); | |
101 | #else | |
102 | gold_unreachable(); | |
103 | #endif | |
104 | } | |
105 | else | |
106 | { | |
107 | #ifdef HAVE_TARGET_64_BIG | |
108 | return this->sized_convert<64, true>(task); | |
109 | #else | |
110 | gold_unreachable(); | |
111 | #endif | |
112 | } | |
113 | } | |
114 | else | |
115 | gold_unreachable(); | |
116 | } | |
117 | ||
118 | // We are going to create: | |
119 | // * The ELF file header. | |
120 | // * Five sections: null section, .data, .symtab, .strtab, .shstrtab | |
121 | // * The contents of the file. | |
122 | // * Four symbols: null, begin, end, size. | |
123 | // * Three symbol names. | |
124 | // * Four section names. | |
125 | ||
126 | template<int size, bool big_endian> | |
127 | bool | |
128 | Binary_to_elf::sized_convert(const Task* task) | |
129 | { | |
130 | // Read the input file. | |
131 | ||
132 | File_read f; | |
133 | if (!f.open(task, this->filename_)) | |
134 | { | |
135 | gold_error(_("cannot open %s: %s:"), this->filename_.c_str(), | |
136 | strerror(errno)); | |
137 | return false; | |
138 | } | |
139 | ||
140 | section_size_type filesize = convert_to_section_size_type(f.filesize()); | |
69d53f7a ILT |
141 | const unsigned char* fileview; |
142 | if (filesize == 0) | |
143 | fileview = NULL; | |
144 | else | |
145 | fileview = f.get_view(0, 0, filesize, false, false); | |
bc644c6c ILT |
146 | |
147 | unsigned int align; | |
148 | if (size == 32) | |
149 | align = 4; | |
150 | else if (size == 64) | |
151 | align = 8; | |
152 | else | |
153 | gold_unreachable(); | |
154 | section_size_type aligned_filesize = align_address(filesize, align); | |
155 | ||
156 | // Build the stringpool for the symbol table. | |
157 | ||
158 | std::string mangled_name = this->filename_; | |
159 | for (std::string::iterator p = mangled_name.begin(); | |
160 | p != mangled_name.end(); | |
161 | ++p) | |
162 | if (!ISALNUM(*p)) | |
163 | *p = '_'; | |
164 | mangled_name = "_binary_" + mangled_name; | |
165 | std::string start_symbol_name = mangled_name + "_start"; | |
166 | std::string end_symbol_name = mangled_name + "_end"; | |
167 | std::string size_symbol_name = mangled_name + "_size"; | |
168 | ||
169 | Stringpool strtab; | |
170 | strtab.add(start_symbol_name.c_str(), false, NULL); | |
171 | strtab.add(end_symbol_name.c_str(), false, NULL); | |
172 | strtab.add(size_symbol_name.c_str(), false, NULL); | |
173 | strtab.set_string_offsets(); | |
174 | ||
175 | // Build the stringpool for the section name table. | |
176 | ||
177 | Stringpool shstrtab; | |
178 | shstrtab.add(".data", false, NULL); | |
179 | shstrtab.add(".symtab", false, NULL); | |
180 | shstrtab.add(".strtab", false, NULL); | |
181 | shstrtab.add(".shstrtab", false, NULL); | |
182 | shstrtab.set_string_offsets(); | |
183 | ||
184 | // Work out the size of the generated file, and the offsets of the | |
185 | // various sections, and allocate a buffer. | |
186 | ||
187 | const int sym_size = elfcpp::Elf_sizes<size>::sym_size; | |
188 | ||
189 | size_t output_size = (elfcpp::Elf_sizes<size>::ehdr_size | |
190 | + 5 * elfcpp::Elf_sizes<size>::shdr_size); | |
191 | size_t data_offset = output_size; | |
192 | output_size += aligned_filesize; | |
193 | size_t symtab_offset = output_size; | |
194 | output_size += 4 * sym_size; | |
195 | size_t strtab_offset = output_size; | |
196 | output_size += strtab.get_strtab_size(); | |
197 | size_t shstrtab_offset = output_size; | |
198 | output_size += shstrtab.get_strtab_size(); | |
199 | ||
200 | unsigned char* buffer = new unsigned char[output_size]; | |
201 | ||
202 | // Write out the data. | |
203 | ||
204 | unsigned char* pout = buffer; | |
205 | ||
206 | this->write_file_header<size, big_endian>(&pout); | |
207 | ||
208 | this->write_section_header<size, big_endian>("", &shstrtab, elfcpp::SHT_NULL, | |
209 | 0, 0, 0, 0, 0, | |
210 | 0, 0, &pout); | |
f0b886e3 ILT |
211 | // Having the section be named ".data", having it be writable, and |
212 | // giving it an alignment of 1 is because the GNU linker does it | |
213 | // that way, and existing linker script expect it. | |
bc644c6c ILT |
214 | this->write_section_header<size, big_endian>(".data", &shstrtab, |
215 | elfcpp::SHT_PROGBITS, | |
216 | (elfcpp::SHF_ALLOC | |
217 | | elfcpp::SHF_WRITE), | |
218 | data_offset, | |
219 | filesize, 0, 0, | |
f0b886e3 | 220 | 1, 0, &pout); |
bc644c6c ILT |
221 | this->write_section_header<size, big_endian>(".symtab", &shstrtab, |
222 | elfcpp::SHT_SYMTAB, | |
223 | 0, symtab_offset, 4 * sym_size, | |
224 | 3, 1, align, sym_size, &pout); | |
225 | this->write_section_header<size, big_endian>(".strtab", &shstrtab, | |
226 | elfcpp::SHT_STRTAB, | |
227 | 0, strtab_offset, | |
228 | strtab.get_strtab_size(), | |
229 | 0, 0, 1, 0, &pout); | |
230 | this->write_section_header<size, big_endian>(".shstrtab", &shstrtab, | |
231 | elfcpp::SHT_STRTAB, | |
232 | 0, shstrtab_offset, | |
233 | shstrtab.get_strtab_size(), | |
234 | 0, 0, 1, 0, &pout); | |
235 | ||
69d53f7a ILT |
236 | if (filesize > 0) |
237 | { | |
238 | memcpy(pout, fileview, filesize); | |
239 | pout += filesize; | |
240 | memset(pout, 0, aligned_filesize - filesize); | |
241 | pout += aligned_filesize - filesize; | |
242 | } | |
bc644c6c | 243 | |
43b64deb CC |
244 | this->write_symbol<size, big_endian>("", &strtab, 0, 0, 0, &pout); |
245 | this->write_symbol<size, big_endian>(start_symbol_name, &strtab, 0, filesize, | |
246 | 1, &pout); | |
247 | this->write_symbol<size, big_endian>(end_symbol_name, &strtab, filesize, 0, | |
248 | 1, &pout); | |
249 | this->write_symbol<size, big_endian>(size_symbol_name, &strtab, filesize, 0, | |
bc644c6c ILT |
250 | elfcpp::SHN_ABS, &pout); |
251 | ||
252 | strtab.write_to_buffer(pout, strtab.get_strtab_size()); | |
253 | pout += strtab.get_strtab_size(); | |
254 | ||
255 | shstrtab.write_to_buffer(pout, shstrtab.get_strtab_size()); | |
256 | pout += shstrtab.get_strtab_size(); | |
257 | ||
258 | gold_assert(static_cast<size_t>(pout - buffer) == output_size); | |
259 | ||
260 | this->data_ = buffer; | |
261 | this->filesize_ = output_size; | |
262 | ||
263 | f.unlock(task); | |
264 | ||
265 | return true; | |
266 | } | |
267 | ||
268 | // Write out the file header. | |
269 | ||
270 | template<int size, bool big_endian> | |
271 | void | |
272 | Binary_to_elf::write_file_header(unsigned char** ppout) | |
273 | { | |
274 | elfcpp::Ehdr_write<size, big_endian> oehdr(*ppout); | |
275 | ||
276 | unsigned char e_ident[elfcpp::EI_NIDENT]; | |
277 | memset(e_ident, 0, elfcpp::EI_NIDENT); | |
278 | e_ident[elfcpp::EI_MAG0] = elfcpp::ELFMAG0; | |
279 | e_ident[elfcpp::EI_MAG1] = elfcpp::ELFMAG1; | |
280 | e_ident[elfcpp::EI_MAG2] = elfcpp::ELFMAG2; | |
281 | e_ident[elfcpp::EI_MAG3] = elfcpp::ELFMAG3; | |
282 | if (size == 32) | |
283 | e_ident[elfcpp::EI_CLASS] = elfcpp::ELFCLASS32; | |
284 | else if (size == 64) | |
285 | e_ident[elfcpp::EI_CLASS] = elfcpp::ELFCLASS64; | |
286 | else | |
287 | gold_unreachable(); | |
288 | e_ident[elfcpp::EI_DATA] = (big_endian | |
289 | ? elfcpp::ELFDATA2MSB | |
290 | : elfcpp::ELFDATA2LSB); | |
291 | e_ident[elfcpp::EI_VERSION] = elfcpp::EV_CURRENT; | |
292 | oehdr.put_e_ident(e_ident); | |
293 | ||
294 | oehdr.put_e_type(elfcpp::ET_REL); | |
295 | oehdr.put_e_machine(this->elf_machine_); | |
296 | oehdr.put_e_version(elfcpp::EV_CURRENT); | |
297 | oehdr.put_e_entry(0); | |
298 | oehdr.put_e_phoff(0); | |
299 | oehdr.put_e_shoff(elfcpp::Elf_sizes<size>::ehdr_size); | |
300 | oehdr.put_e_flags(0); | |
301 | oehdr.put_e_ehsize(elfcpp::Elf_sizes<size>::ehdr_size); | |
302 | oehdr.put_e_phentsize(0); | |
303 | oehdr.put_e_phnum(0); | |
304 | oehdr.put_e_shentsize(elfcpp::Elf_sizes<size>::shdr_size); | |
305 | oehdr.put_e_shnum(5); | |
306 | oehdr.put_e_shstrndx(4); | |
307 | ||
308 | *ppout += elfcpp::Elf_sizes<size>::ehdr_size; | |
309 | } | |
310 | ||
311 | // Write out a section header. | |
312 | ||
313 | template<int size, bool big_endian> | |
314 | void | |
315 | Binary_to_elf::write_section_header( | |
316 | const char* name, | |
317 | const Stringpool* shstrtab, | |
318 | elfcpp::SHT type, | |
319 | unsigned int flags, | |
320 | section_size_type offset, | |
321 | section_size_type section_size, | |
322 | unsigned int link, | |
323 | unsigned int info, | |
324 | unsigned int addralign, | |
325 | unsigned int entsize, | |
326 | unsigned char** ppout) | |
327 | { | |
328 | elfcpp::Shdr_write<size, big_endian> oshdr(*ppout); | |
329 | ||
330 | oshdr.put_sh_name(*name == '\0' ? 0 : shstrtab->get_offset(name)); | |
331 | oshdr.put_sh_type(type); | |
332 | oshdr.put_sh_flags(flags); | |
333 | oshdr.put_sh_addr(0); | |
334 | oshdr.put_sh_offset(offset); | |
335 | oshdr.put_sh_size(section_size); | |
336 | oshdr.put_sh_link(link); | |
337 | oshdr.put_sh_info(info); | |
338 | oshdr.put_sh_addralign(addralign); | |
339 | oshdr.put_sh_entsize(entsize); | |
340 | ||
341 | *ppout += elfcpp::Elf_sizes<size>::shdr_size; | |
342 | } | |
343 | ||
344 | // Write out a symbol. | |
345 | ||
346 | template<int size, bool big_endian> | |
347 | void | |
348 | Binary_to_elf::write_symbol( | |
349 | const std::string& name, | |
350 | const Stringpool* strtab, | |
351 | section_size_type value, | |
43b64deb | 352 | typename elfcpp::Elf_types<32>::Elf_WXword st_size, |
bc644c6c ILT |
353 | unsigned int shndx, |
354 | unsigned char** ppout) | |
355 | { | |
356 | unsigned char* pout = *ppout; | |
357 | ||
358 | elfcpp::Sym_write<size, big_endian> osym(pout); | |
359 | osym.put_st_name(name.empty() ? 0 : strtab->get_offset(name.c_str())); | |
360 | osym.put_st_value(value); | |
43b64deb | 361 | osym.put_st_size(st_size); |
bc644c6c ILT |
362 | osym.put_st_info(name.empty() ? elfcpp::STB_LOCAL : elfcpp::STB_GLOBAL, |
363 | elfcpp::STT_NOTYPE); | |
364 | osym.put_st_other(elfcpp::STV_DEFAULT, 0); | |
365 | osym.put_st_shndx(shndx); | |
366 | ||
367 | *ppout += elfcpp::Elf_sizes<size>::sym_size; | |
368 | } | |
369 | ||
370 | } // End namespace gold. |