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dbe717ef ILT |
1 | // dynobj.cc -- dynamic object support for gold |
2 | ||
3 | #include "gold.h" | |
4 | ||
5 | #include <vector> | |
6 | #include <cstring> | |
7 | ||
a3ad94ed | 8 | #include "elfcpp.h" |
dbe717ef ILT |
9 | #include "symtab.h" |
10 | #include "dynobj.h" | |
11 | ||
12 | namespace gold | |
13 | { | |
14 | ||
a3ad94ed ILT |
15 | // Class Dynobj. |
16 | ||
17 | // Return the string to use in a DT_NEEDED entry. | |
18 | ||
19 | const char* | |
20 | Dynobj::soname() const | |
21 | { | |
22 | if (!this->soname_.empty()) | |
23 | return this->soname_.c_str(); | |
24 | return this->name().c_str(); | |
25 | } | |
26 | ||
dbe717ef ILT |
27 | // Class Sized_dynobj. |
28 | ||
29 | template<int size, bool big_endian> | |
30 | Sized_dynobj<size, big_endian>::Sized_dynobj( | |
31 | const std::string& name, | |
32 | Input_file* input_file, | |
33 | off_t offset, | |
34 | const elfcpp::Ehdr<size, big_endian>& ehdr) | |
35 | : Dynobj(name, input_file, offset), | |
a3ad94ed | 36 | elf_file_(this, ehdr) |
dbe717ef ILT |
37 | { |
38 | } | |
39 | ||
40 | // Set up the object. | |
41 | ||
42 | template<int size, bool big_endian> | |
43 | void | |
44 | Sized_dynobj<size, big_endian>::setup( | |
45 | const elfcpp::Ehdr<size, big_endian>& ehdr) | |
46 | { | |
47 | this->set_target(ehdr.get_e_machine(), size, big_endian, | |
48 | ehdr.get_e_ident()[elfcpp::EI_OSABI], | |
49 | ehdr.get_e_ident()[elfcpp::EI_ABIVERSION]); | |
50 | ||
51 | const unsigned int shnum = this->elf_file_.shnum(); | |
52 | this->set_shnum(shnum); | |
53 | } | |
54 | ||
55 | // Find the SHT_DYNSYM section and the various version sections, and | |
56 | // the dynamic section, given the section headers. | |
57 | ||
58 | template<int size, bool big_endian> | |
59 | void | |
60 | Sized_dynobj<size, big_endian>::find_dynsym_sections( | |
61 | const unsigned char* pshdrs, | |
62 | unsigned int* pdynsym_shndx, | |
63 | unsigned int* pversym_shndx, | |
64 | unsigned int* pverdef_shndx, | |
65 | unsigned int* pverneed_shndx, | |
66 | unsigned int* pdynamic_shndx) | |
67 | { | |
68 | *pdynsym_shndx = -1U; | |
69 | *pversym_shndx = -1U; | |
70 | *pverdef_shndx = -1U; | |
71 | *pverneed_shndx = -1U; | |
72 | *pdynamic_shndx = -1U; | |
73 | ||
74 | const unsigned int shnum = this->shnum(); | |
75 | const unsigned char* p = pshdrs; | |
76 | for (unsigned int i = 0; i < shnum; ++i, p += This::shdr_size) | |
77 | { | |
78 | typename This::Shdr shdr(p); | |
79 | ||
80 | unsigned int* pi; | |
81 | switch (shdr.get_sh_type()) | |
82 | { | |
83 | case elfcpp::SHT_DYNSYM: | |
84 | pi = pdynsym_shndx; | |
85 | break; | |
86 | case elfcpp::SHT_GNU_versym: | |
87 | pi = pversym_shndx; | |
88 | break; | |
89 | case elfcpp::SHT_GNU_verdef: | |
90 | pi = pverdef_shndx; | |
91 | break; | |
92 | case elfcpp::SHT_GNU_verneed: | |
93 | pi = pverneed_shndx; | |
94 | break; | |
95 | case elfcpp::SHT_DYNAMIC: | |
96 | pi = pdynamic_shndx; | |
97 | break; | |
98 | default: | |
99 | pi = NULL; | |
100 | break; | |
101 | } | |
102 | ||
103 | if (pi == NULL) | |
104 | continue; | |
105 | ||
106 | if (*pi != -1U) | |
107 | { | |
108 | fprintf(stderr, | |
109 | _("%s: %s: unexpected duplicate type %u section: %u, %u\n"), | |
110 | program_name, this->name().c_str(), shdr.get_sh_type(), | |
111 | *pi, i); | |
112 | gold_exit(false); | |
113 | } | |
114 | ||
115 | *pi = i; | |
116 | } | |
117 | } | |
118 | ||
119 | // Read the contents of section SHNDX. PSHDRS points to the section | |
120 | // headers. TYPE is the expected section type. LINK is the expected | |
121 | // section link. Store the data in *VIEW and *VIEW_SIZE. The | |
122 | // section's sh_info field is stored in *VIEW_INFO. | |
123 | ||
124 | template<int size, bool big_endian> | |
125 | void | |
126 | Sized_dynobj<size, big_endian>::read_dynsym_section( | |
127 | const unsigned char* pshdrs, | |
128 | unsigned int shndx, | |
129 | elfcpp::SHT type, | |
130 | unsigned int link, | |
131 | File_view** view, | |
132 | off_t* view_size, | |
133 | unsigned int* view_info) | |
134 | { | |
135 | if (shndx == -1U) | |
136 | { | |
137 | *view = NULL; | |
138 | *view_size = 0; | |
139 | *view_info = 0; | |
140 | return; | |
141 | } | |
142 | ||
143 | typename This::Shdr shdr(pshdrs + shndx * This::shdr_size); | |
144 | ||
a3ad94ed | 145 | gold_assert(shdr.get_sh_type() == type); |
dbe717ef ILT |
146 | |
147 | if (shdr.get_sh_link() != link) | |
148 | { | |
149 | fprintf(stderr, | |
150 | _("%s: %s: unexpected link in section %u header: %u != %u\n"), | |
151 | program_name, this->name().c_str(), shndx, | |
152 | shdr.get_sh_link(), link); | |
153 | gold_exit(false); | |
154 | } | |
155 | ||
156 | *view = this->get_lasting_view(shdr.get_sh_offset(), shdr.get_sh_size()); | |
157 | *view_size = shdr.get_sh_size(); | |
158 | *view_info = shdr.get_sh_info(); | |
159 | } | |
160 | ||
a3ad94ed ILT |
161 | // Set the soname field if this shared object has a DT_SONAME tag. |
162 | // PSHDRS points to the section headers. DYNAMIC_SHNDX is the section | |
163 | // index of the SHT_DYNAMIC section. STRTAB_SHNDX, STRTAB, and | |
164 | // STRTAB_SIZE are the section index and contents of a string table | |
165 | // which may be the one associated with the SHT_DYNAMIC section. | |
dbe717ef ILT |
166 | |
167 | template<int size, bool big_endian> | |
168 | void | |
169 | Sized_dynobj<size, big_endian>::set_soname(const unsigned char* pshdrs, | |
170 | unsigned int dynamic_shndx, | |
171 | unsigned int strtab_shndx, | |
172 | const unsigned char* strtabu, | |
173 | off_t strtab_size) | |
174 | { | |
175 | typename This::Shdr dynamicshdr(pshdrs + dynamic_shndx * This::shdr_size); | |
a3ad94ed | 176 | gold_assert(dynamicshdr.get_sh_type() == elfcpp::SHT_DYNAMIC); |
dbe717ef ILT |
177 | |
178 | const off_t dynamic_size = dynamicshdr.get_sh_size(); | |
179 | const unsigned char* pdynamic = this->get_view(dynamicshdr.get_sh_offset(), | |
180 | dynamic_size); | |
181 | ||
182 | const unsigned int link = dynamicshdr.get_sh_link(); | |
183 | if (link != strtab_shndx) | |
184 | { | |
185 | if (link >= this->shnum()) | |
186 | { | |
187 | fprintf(stderr, | |
188 | _("%s: %s: DYNAMIC section %u link out of range: %u\n"), | |
189 | program_name, this->name().c_str(), | |
190 | dynamic_shndx, link); | |
191 | gold_exit(false); | |
192 | } | |
193 | ||
194 | typename This::Shdr strtabshdr(pshdrs + link * This::shdr_size); | |
195 | if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB) | |
196 | { | |
197 | fprintf(stderr, | |
198 | _("%s: %s: DYNAMIC section %u link %u is not a strtab\n"), | |
199 | program_name, this->name().c_str(), | |
200 | dynamic_shndx, link); | |
201 | gold_exit(false); | |
202 | } | |
203 | ||
204 | strtab_size = strtabshdr.get_sh_size(); | |
205 | strtabu = this->get_view(strtabshdr.get_sh_offset(), strtab_size); | |
206 | } | |
207 | ||
208 | for (const unsigned char* p = pdynamic; | |
209 | p < pdynamic + dynamic_size; | |
210 | p += This::dyn_size) | |
211 | { | |
212 | typename This::Dyn dyn(p); | |
213 | ||
214 | if (dyn.get_d_tag() == elfcpp::DT_SONAME) | |
215 | { | |
216 | off_t val = dyn.get_d_val(); | |
217 | if (val >= strtab_size) | |
218 | { | |
219 | fprintf(stderr, | |
220 | _("%s: %s: DT_SONAME value out of range: " | |
221 | "%lld >= %lld\n"), | |
222 | program_name, this->name().c_str(), | |
223 | static_cast<long long>(val), | |
224 | static_cast<long long>(strtab_size)); | |
225 | gold_exit(false); | |
226 | } | |
227 | ||
228 | const char* strtab = reinterpret_cast<const char*>(strtabu); | |
a3ad94ed | 229 | this->set_soname_string(strtab + val); |
dbe717ef ILT |
230 | return; |
231 | } | |
232 | ||
233 | if (dyn.get_d_tag() == elfcpp::DT_NULL) | |
234 | return; | |
235 | } | |
236 | ||
237 | fprintf(stderr, _("%s: %s: missing DT_NULL in dynamic segment\n"), | |
238 | program_name, this->name().c_str()); | |
239 | gold_exit(false); | |
240 | } | |
241 | ||
242 | // Read the symbols and sections from a dynamic object. We read the | |
243 | // dynamic symbols, not the normal symbols. | |
244 | ||
245 | template<int size, bool big_endian> | |
246 | void | |
247 | Sized_dynobj<size, big_endian>::do_read_symbols(Read_symbols_data* sd) | |
248 | { | |
249 | this->read_section_data(&this->elf_file_, sd); | |
250 | ||
251 | const unsigned char* const pshdrs = sd->section_headers->data(); | |
252 | ||
253 | unsigned int dynsym_shndx; | |
254 | unsigned int versym_shndx; | |
255 | unsigned int verdef_shndx; | |
256 | unsigned int verneed_shndx; | |
257 | unsigned int dynamic_shndx; | |
258 | this->find_dynsym_sections(pshdrs, &dynsym_shndx, &versym_shndx, | |
259 | &verdef_shndx, &verneed_shndx, &dynamic_shndx); | |
260 | ||
261 | unsigned int strtab_shndx = -1U; | |
262 | ||
263 | if (dynsym_shndx == -1U) | |
264 | { | |
265 | sd->symbols = NULL; | |
266 | sd->symbols_size = 0; | |
267 | sd->symbol_names = NULL; | |
268 | sd->symbol_names_size = 0; | |
269 | } | |
270 | else | |
271 | { | |
272 | // Get the dynamic symbols. | |
273 | typename This::Shdr dynsymshdr(pshdrs + dynsym_shndx * This::shdr_size); | |
a3ad94ed | 274 | gold_assert(dynsymshdr.get_sh_type() == elfcpp::SHT_DYNSYM); |
dbe717ef ILT |
275 | |
276 | sd->symbols = this->get_lasting_view(dynsymshdr.get_sh_offset(), | |
277 | dynsymshdr.get_sh_size()); | |
278 | sd->symbols_size = dynsymshdr.get_sh_size(); | |
279 | ||
280 | // Get the symbol names. | |
281 | strtab_shndx = dynsymshdr.get_sh_link(); | |
282 | if (strtab_shndx >= this->shnum()) | |
283 | { | |
284 | fprintf(stderr, | |
285 | _("%s: %s: invalid dynamic symbol table name index: %u\n"), | |
286 | program_name, this->name().c_str(), strtab_shndx); | |
287 | gold_exit(false); | |
288 | } | |
289 | typename This::Shdr strtabshdr(pshdrs + strtab_shndx * This::shdr_size); | |
290 | if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB) | |
291 | { | |
292 | fprintf(stderr, | |
293 | _("%s: %s: dynamic symbol table name section " | |
294 | "has wrong type: %u\n"), | |
295 | program_name, this->name().c_str(), | |
296 | static_cast<unsigned int>(strtabshdr.get_sh_type())); | |
297 | gold_exit(false); | |
298 | } | |
299 | ||
300 | sd->symbol_names = this->get_lasting_view(strtabshdr.get_sh_offset(), | |
301 | strtabshdr.get_sh_size()); | |
302 | sd->symbol_names_size = strtabshdr.get_sh_size(); | |
303 | ||
304 | // Get the version information. | |
305 | ||
306 | unsigned int dummy; | |
307 | this->read_dynsym_section(pshdrs, versym_shndx, elfcpp::SHT_GNU_versym, | |
308 | dynsym_shndx, &sd->versym, &sd->versym_size, | |
309 | &dummy); | |
310 | ||
311 | // We require that the version definition and need section link | |
312 | // to the same string table as the dynamic symbol table. This | |
313 | // is not a technical requirement, but it always happens in | |
314 | // practice. We could change this if necessary. | |
315 | ||
316 | this->read_dynsym_section(pshdrs, verdef_shndx, elfcpp::SHT_GNU_verdef, | |
317 | strtab_shndx, &sd->verdef, &sd->verdef_size, | |
318 | &sd->verdef_info); | |
319 | ||
320 | this->read_dynsym_section(pshdrs, verneed_shndx, elfcpp::SHT_GNU_verneed, | |
321 | strtab_shndx, &sd->verneed, &sd->verneed_size, | |
322 | &sd->verneed_info); | |
323 | } | |
324 | ||
325 | // Read the SHT_DYNAMIC section to find whether this shared object | |
326 | // has a DT_SONAME tag. This doesn't really have anything to do | |
327 | // with reading the symbols, but this is a convenient place to do | |
328 | // it. | |
329 | if (dynamic_shndx != -1U) | |
330 | this->set_soname(pshdrs, dynamic_shndx, strtab_shndx, | |
331 | (sd->symbol_names == NULL | |
332 | ? NULL | |
333 | : sd->symbol_names->data()), | |
334 | sd->symbol_names_size); | |
335 | } | |
336 | ||
337 | // Lay out the input sections for a dynamic object. We don't want to | |
338 | // include sections from a dynamic object, so all that we actually do | |
339 | // here is check for .gnu.warning sections. | |
340 | ||
341 | template<int size, bool big_endian> | |
342 | void | |
343 | Sized_dynobj<size, big_endian>::do_layout(const General_options&, | |
344 | Symbol_table* symtab, | |
345 | Layout*, | |
346 | Read_symbols_data* sd) | |
347 | { | |
348 | const unsigned int shnum = this->shnum(); | |
349 | if (shnum == 0) | |
350 | return; | |
351 | ||
352 | // Get the section headers. | |
353 | const unsigned char* pshdrs = sd->section_headers->data(); | |
354 | ||
355 | // Get the section names. | |
356 | const unsigned char* pnamesu = sd->section_names->data(); | |
357 | const char* pnames = reinterpret_cast<const char*>(pnamesu); | |
358 | ||
359 | // Skip the first, dummy, section. | |
360 | pshdrs += This::shdr_size; | |
361 | for (unsigned int i = 1; i < shnum; ++i, pshdrs += This::shdr_size) | |
362 | { | |
363 | typename This::Shdr shdr(pshdrs); | |
364 | ||
365 | if (shdr.get_sh_name() >= sd->section_names_size) | |
366 | { | |
367 | fprintf(stderr, | |
368 | _("%s: %s: bad section name offset for section %u: %lu\n"), | |
369 | program_name, this->name().c_str(), i, | |
370 | static_cast<unsigned long>(shdr.get_sh_name())); | |
371 | gold_exit(false); | |
372 | } | |
373 | ||
374 | const char* name = pnames + shdr.get_sh_name(); | |
375 | ||
376 | this->handle_gnu_warning_section(name, i, symtab); | |
377 | } | |
378 | ||
379 | delete sd->section_headers; | |
380 | sd->section_headers = NULL; | |
381 | delete sd->section_names; | |
382 | sd->section_names = NULL; | |
383 | } | |
384 | ||
385 | // Add an entry to the vector mapping version numbers to version | |
386 | // strings. | |
387 | ||
388 | template<int size, bool big_endian> | |
389 | void | |
390 | Sized_dynobj<size, big_endian>::set_version_map( | |
391 | Version_map* version_map, | |
392 | unsigned int ndx, | |
393 | const char* name) const | |
394 | { | |
a3ad94ed | 395 | gold_assert(ndx < version_map->size()); |
dbe717ef ILT |
396 | if ((*version_map)[ndx] != NULL) |
397 | { | |
398 | fprintf(stderr, _("%s: %s: duplicate definition for version %u\n"), | |
399 | program_name, this->name().c_str(), ndx); | |
400 | gold_exit(false); | |
401 | } | |
402 | (*version_map)[ndx] = name; | |
403 | } | |
404 | ||
405 | // Create a vector mapping version numbers to version strings. | |
406 | ||
407 | template<int size, bool big_endian> | |
408 | void | |
409 | Sized_dynobj<size, big_endian>::make_version_map( | |
410 | Read_symbols_data* sd, | |
411 | Version_map* version_map) const | |
412 | { | |
413 | if (sd->verdef == NULL && sd->verneed == NULL) | |
414 | return; | |
415 | ||
416 | // First find the largest version index. | |
417 | unsigned int maxver = 0; | |
418 | ||
419 | if (sd->verdef != NULL) | |
420 | { | |
421 | const unsigned char* pverdef = sd->verdef->data(); | |
422 | off_t verdef_size = sd->verdef_size; | |
423 | const unsigned int count = sd->verdef_info; | |
424 | ||
425 | const unsigned char* p = pverdef; | |
426 | for (unsigned int i = 0; i < count; ++i) | |
427 | { | |
428 | elfcpp::Verdef<size, big_endian> verdef(p); | |
429 | ||
430 | const unsigned int vd_ndx = verdef.get_vd_ndx(); | |
431 | ||
432 | // The GNU linker clears the VERSYM_HIDDEN bit. I'm not | |
433 | // sure why. | |
434 | ||
435 | if (vd_ndx > maxver) | |
436 | maxver = vd_ndx; | |
437 | ||
438 | const unsigned int vd_next = verdef.get_vd_next(); | |
439 | if ((p - pverdef) + vd_next >= verdef_size) | |
440 | { | |
441 | fprintf(stderr, | |
442 | _("%s: %s: verdef vd_next field out of range: %u\n"), | |
443 | program_name, this->name().c_str(), vd_next); | |
444 | gold_exit(false); | |
445 | } | |
446 | ||
447 | p += vd_next; | |
448 | } | |
449 | } | |
450 | ||
451 | if (sd->verneed != NULL) | |
452 | { | |
453 | const unsigned char* pverneed = sd->verneed->data(); | |
454 | off_t verneed_size = sd->verneed_size; | |
455 | const unsigned int count = sd->verneed_info; | |
456 | ||
457 | const unsigned char* p = pverneed; | |
458 | for (unsigned int i = 0; i < count; ++i) | |
459 | { | |
460 | elfcpp::Verneed<size, big_endian> verneed(p); | |
461 | ||
462 | const unsigned int vn_aux = verneed.get_vn_aux(); | |
463 | if ((p - pverneed) + vn_aux >= verneed_size) | |
464 | { | |
465 | fprintf(stderr, | |
466 | _("%s: %s: verneed vn_aux field out of range: %u\n"), | |
467 | program_name, this->name().c_str(), vn_aux); | |
468 | gold_exit(false); | |
469 | } | |
470 | ||
471 | const unsigned int vn_cnt = verneed.get_vn_cnt(); | |
472 | const unsigned char* pvna = p + vn_aux; | |
473 | for (unsigned int j = 0; j < vn_cnt; ++j) | |
474 | { | |
475 | elfcpp::Vernaux<size, big_endian> vernaux(pvna); | |
476 | ||
477 | const unsigned int vna_other = vernaux.get_vna_other(); | |
478 | if (vna_other > maxver) | |
479 | maxver = vna_other; | |
480 | ||
481 | const unsigned int vna_next = vernaux.get_vna_next(); | |
482 | if ((pvna - pverneed) + vna_next >= verneed_size) | |
483 | { | |
484 | fprintf(stderr, | |
485 | _("%s: %s: verneed vna_next field " | |
486 | "out of range: %u\n"), | |
487 | program_name, this->name().c_str(), vna_next); | |
488 | gold_exit(false); | |
489 | } | |
490 | ||
491 | pvna += vna_next; | |
492 | } | |
493 | ||
494 | const unsigned int vn_next = verneed.get_vn_next(); | |
495 | if ((p - pverneed) + vn_next >= verneed_size) | |
496 | { | |
497 | fprintf(stderr, | |
498 | _("%s: %s: verneed vn_next field out of range: %u\n"), | |
499 | program_name, this->name().c_str(), vn_next); | |
500 | gold_exit(false); | |
501 | } | |
502 | ||
503 | p += vn_next; | |
504 | } | |
505 | } | |
506 | ||
507 | // Now MAXVER is the largest version index we have seen. | |
508 | ||
509 | version_map->resize(maxver + 1); | |
510 | ||
511 | const char* names = reinterpret_cast<const char*>(sd->symbol_names->data()); | |
512 | off_t names_size = sd->symbol_names_size; | |
513 | ||
514 | if (sd->verdef != NULL) | |
515 | { | |
516 | const unsigned char* pverdef = sd->verdef->data(); | |
517 | off_t verdef_size = sd->verdef_size; | |
518 | const unsigned int count = sd->verdef_info; | |
519 | ||
520 | const unsigned char* p = pverdef; | |
521 | for (unsigned int i = 0; i < count; ++i) | |
522 | { | |
523 | elfcpp::Verdef<size, big_endian> verdef(p); | |
524 | ||
525 | const unsigned int vd_cnt = verdef.get_vd_cnt(); | |
526 | if (vd_cnt < 1) | |
527 | { | |
528 | fprintf(stderr, _("%s: %s: verdef vd_cnt field too small: %u\n"), | |
529 | program_name, this->name().c_str(), vd_cnt); | |
530 | gold_exit(false); | |
531 | } | |
532 | ||
533 | const unsigned int vd_aux = verdef.get_vd_aux(); | |
534 | if ((p - pverdef) + vd_aux >= verdef_size) | |
535 | { | |
536 | fprintf(stderr, | |
537 | _("%s: %s: verdef vd_aux field out of range: %u\n"), | |
538 | program_name, this->name().c_str(), vd_aux); | |
539 | gold_exit(false); | |
540 | } | |
541 | ||
542 | const unsigned char* pvda = p + vd_aux; | |
543 | elfcpp::Verdaux<size, big_endian> verdaux(pvda); | |
544 | ||
545 | const unsigned int vda_name = verdaux.get_vda_name(); | |
546 | if (vda_name >= names_size) | |
547 | { | |
548 | fprintf(stderr, | |
549 | _("%s: %s: verdaux vda_name field out of range: %u\n"), | |
550 | program_name, this->name().c_str(), vda_name); | |
551 | gold_exit(false); | |
552 | } | |
553 | ||
554 | this->set_version_map(version_map, verdef.get_vd_ndx(), | |
555 | names + vda_name); | |
556 | ||
557 | const unsigned int vd_next = verdef.get_vd_next(); | |
558 | if ((p - pverdef) + vd_next >= verdef_size) | |
559 | { | |
560 | fprintf(stderr, | |
561 | _("%s: %s: verdef vd_next field out of range: %u\n"), | |
562 | program_name, this->name().c_str(), vd_next); | |
563 | gold_exit(false); | |
564 | } | |
565 | ||
566 | p += vd_next; | |
567 | } | |
568 | } | |
569 | ||
570 | if (sd->verneed != NULL) | |
571 | { | |
572 | const unsigned char* pverneed = sd->verneed->data(); | |
573 | const unsigned int count = sd->verneed_info; | |
574 | ||
575 | const unsigned char* p = pverneed; | |
576 | for (unsigned int i = 0; i < count; ++i) | |
577 | { | |
578 | elfcpp::Verneed<size, big_endian> verneed(p); | |
579 | ||
580 | const unsigned int vn_aux = verneed.get_vn_aux(); | |
581 | const unsigned int vn_cnt = verneed.get_vn_cnt(); | |
582 | const unsigned char* pvna = p + vn_aux; | |
583 | for (unsigned int j = 0; j < vn_cnt; ++j) | |
584 | { | |
585 | elfcpp::Vernaux<size, big_endian> vernaux(pvna); | |
586 | ||
587 | const unsigned int vna_name = vernaux.get_vna_name(); | |
588 | if (vna_name >= names_size) | |
589 | { | |
590 | fprintf(stderr, | |
591 | _("%s: %s: vernaux vna_name field " | |
592 | "out of range: %u\n"), | |
593 | program_name, this->name().c_str(), vna_name); | |
594 | gold_exit(false); | |
595 | } | |
596 | ||
597 | this->set_version_map(version_map, vernaux.get_vna_other(), | |
598 | names + vna_name); | |
599 | ||
600 | pvna += vernaux.get_vna_next(); | |
601 | } | |
602 | ||
603 | p += verneed.get_vn_next(); | |
604 | } | |
605 | } | |
606 | } | |
607 | ||
608 | // Add the dynamic symbols to the symbol table. | |
609 | ||
610 | template<int size, bool big_endian> | |
611 | void | |
612 | Sized_dynobj<size, big_endian>::do_add_symbols(Symbol_table* symtab, | |
613 | Read_symbols_data* sd) | |
614 | { | |
615 | if (sd->symbols == NULL) | |
616 | { | |
a3ad94ed ILT |
617 | gold_assert(sd->symbol_names == NULL); |
618 | gold_assert(sd->versym == NULL && sd->verdef == NULL | |
619 | && sd->verneed == NULL); | |
dbe717ef ILT |
620 | return; |
621 | } | |
622 | ||
623 | const int sym_size = This::sym_size; | |
624 | const size_t symcount = sd->symbols_size / sym_size; | |
625 | if (symcount * sym_size != sd->symbols_size) | |
626 | { | |
627 | fprintf(stderr, | |
628 | _("%s: %s: size of dynamic symbols is not " | |
629 | "multiple of symbol size\n"), | |
630 | program_name, this->name().c_str()); | |
631 | gold_exit(false); | |
632 | } | |
633 | ||
634 | Version_map version_map; | |
635 | this->make_version_map(sd, &version_map); | |
636 | ||
637 | const char* sym_names = | |
638 | reinterpret_cast<const char*>(sd->symbol_names->data()); | |
639 | symtab->add_from_dynobj(this, sd->symbols->data(), symcount, | |
640 | sym_names, sd->symbol_names_size, | |
641 | (sd->versym == NULL | |
642 | ? NULL | |
643 | : sd->versym->data()), | |
644 | sd->versym_size, | |
645 | &version_map); | |
646 | ||
647 | delete sd->symbols; | |
648 | sd->symbols = NULL; | |
649 | delete sd->symbol_names; | |
650 | sd->symbol_names = NULL; | |
651 | if (sd->versym != NULL) | |
652 | { | |
653 | delete sd->versym; | |
654 | sd->versym = NULL; | |
655 | } | |
656 | if (sd->verdef != NULL) | |
657 | { | |
658 | delete sd->verdef; | |
659 | sd->verdef = NULL; | |
660 | } | |
661 | if (sd->verneed != NULL) | |
662 | { | |
663 | delete sd->verneed; | |
664 | sd->verneed = NULL; | |
665 | } | |
666 | } | |
667 | ||
a3ad94ed ILT |
668 | // Given a vector of hash codes, compute the number of hash buckets to |
669 | // use. | |
670 | ||
671 | unsigned int | |
672 | Dynobj::compute_bucket_count(const std::vector<uint32_t>& hashcodes, | |
673 | bool for_gnu_hash_table) | |
674 | { | |
675 | // FIXME: Implement optional hash table optimization. | |
676 | ||
677 | // Array used to determine the number of hash table buckets to use | |
678 | // based on the number of symbols there are. If there are fewer | |
679 | // than 3 symbols we use 1 bucket, fewer than 17 symbols we use 3 | |
680 | // buckets, fewer than 37 we use 17 buckets, and so forth. We never | |
681 | // use more than 32771 buckets. This is straight from the old GNU | |
682 | // linker. | |
683 | static const unsigned int buckets[] = | |
684 | { | |
685 | 1, 3, 17, 37, 67, 97, 131, 197, 263, 521, 1031, 2053, 4099, 8209, | |
686 | 16411, 32771 | |
687 | }; | |
688 | const int buckets_count = sizeof buckets / sizeof buckets[0]; | |
689 | ||
690 | unsigned int symcount = hashcodes.size(); | |
691 | unsigned int ret = 1; | |
692 | for (int i = 0; i < buckets_count; ++i) | |
693 | { | |
694 | if (symcount < buckets[i]) | |
695 | break; | |
696 | ret = buckets[i]; | |
697 | } | |
698 | ||
699 | if (for_gnu_hash_table && ret < 2) | |
700 | ret = 2; | |
701 | ||
702 | return ret; | |
703 | } | |
704 | ||
705 | // The standard ELF hash function. This hash function must not | |
706 | // change, as the dynamic linker uses it also. | |
707 | ||
708 | uint32_t | |
709 | Dynobj::elf_hash(const char* name) | |
710 | { | |
711 | const unsigned char* nameu = reinterpret_cast<const unsigned char*>(name); | |
712 | uint32_t h = 0; | |
713 | unsigned char c; | |
714 | while ((c = *nameu++) != '\0') | |
715 | { | |
716 | h = (h << 4) + c; | |
717 | uint32_t g = h & 0xf0000000; | |
718 | if (g != 0) | |
719 | { | |
720 | h ^= g >> 24; | |
721 | // The ELF ABI says h &= ~g, but using xor is equivalent in | |
722 | // this case (since g was set from h) and may save one | |
723 | // instruction. | |
724 | h ^= g; | |
725 | } | |
726 | } | |
727 | return h; | |
728 | } | |
729 | ||
730 | // Create a standard ELF hash table, setting *PPHASH and *PHASHLEN. | |
731 | // DYNSYMS is a vector with all the global dynamic symbols. | |
732 | // LOCAL_DYNSYM_COUNT is the number of local symbols in the dynamic | |
733 | // symbol table. | |
734 | ||
735 | void | |
736 | Dynobj::create_elf_hash_table(const Target* target, | |
737 | const std::vector<Symbol*>& dynsyms, | |
738 | unsigned int local_dynsym_count, | |
739 | unsigned char** pphash, | |
740 | unsigned int* phashlen) | |
741 | { | |
742 | unsigned int dynsym_count = dynsyms.size(); | |
743 | ||
744 | // Get the hash values for all the symbols. | |
745 | std::vector<uint32_t> dynsym_hashvals(dynsym_count); | |
746 | for (unsigned int i = 0; i < dynsym_count; ++i) | |
747 | dynsym_hashvals[i] = Dynobj::elf_hash(dynsyms[i]->name()); | |
748 | ||
749 | const unsigned int bucketcount = | |
750 | Dynobj::compute_bucket_count(dynsym_hashvals, false); | |
751 | ||
752 | std::vector<uint32_t> bucket(bucketcount); | |
753 | std::vector<uint32_t> chain(local_dynsym_count + dynsym_count); | |
754 | ||
755 | for (unsigned int i = 0; i < dynsym_count; ++i) | |
756 | { | |
757 | unsigned int dynsym_index = dynsyms[i]->dynsym_index(); | |
758 | unsigned int bucketpos = dynsym_hashvals[i] % bucketcount; | |
759 | chain[dynsym_index] = bucket[bucketpos]; | |
760 | bucket[bucketpos] = dynsym_index; | |
761 | } | |
762 | ||
763 | unsigned int hashlen = ((2 | |
764 | + bucketcount | |
765 | + local_dynsym_count | |
766 | + dynsym_count) | |
767 | * 4); | |
768 | unsigned char* phash = new unsigned char[hashlen]; | |
769 | ||
770 | if (target->is_big_endian()) | |
771 | Dynobj::sized_create_elf_hash_table<true>(bucket, chain, phash, hashlen); | |
772 | else | |
773 | Dynobj::sized_create_elf_hash_table<false>(bucket, chain, phash, hashlen); | |
774 | ||
775 | *pphash = phash; | |
776 | *phashlen = hashlen; | |
777 | } | |
778 | ||
779 | // Fill in an ELF hash table. | |
780 | ||
781 | template<bool big_endian> | |
782 | void | |
783 | Dynobj::sized_create_elf_hash_table(const std::vector<uint32_t>& bucket, | |
784 | const std::vector<uint32_t>& chain, | |
785 | unsigned char* phash, | |
786 | unsigned int hashlen) | |
787 | { | |
788 | unsigned char* p = phash; | |
789 | ||
790 | const unsigned int bucketcount = bucket.size(); | |
791 | const unsigned int chaincount = chain.size(); | |
792 | ||
793 | elfcpp::Swap<32, big_endian>::writeval(p, bucketcount); | |
794 | p += 4; | |
795 | elfcpp::Swap<32, big_endian>::writeval(p, chaincount); | |
796 | p += 4; | |
797 | ||
798 | for (unsigned int i = 0; i < bucketcount; ++i) | |
799 | { | |
800 | elfcpp::Swap<32, big_endian>::writeval(p, bucket[i]); | |
801 | p += 4; | |
802 | } | |
803 | ||
804 | for (unsigned int i = 0; i < chaincount; ++i) | |
805 | { | |
806 | elfcpp::Swap<32, big_endian>::writeval(p, chain[i]); | |
807 | p += 4; | |
808 | } | |
809 | ||
810 | gold_assert(static_cast<unsigned int>(p - phash) == hashlen); | |
811 | } | |
812 | ||
813 | // The hash function used for the GNU hash table. This hash function | |
814 | // must not change, as the dynamic linker uses it also. | |
815 | ||
816 | uint32_t | |
817 | Dynobj::gnu_hash(const char* name) | |
818 | { | |
819 | const unsigned char* nameu = reinterpret_cast<const unsigned char*>(name); | |
820 | uint32_t h = 5381; | |
821 | unsigned char c; | |
822 | while ((c = *nameu++) != '\0') | |
823 | h = (h << 5) + h + c; | |
824 | return h; | |
825 | } | |
826 | ||
827 | // Create a GNU hash table, setting *PPHASH and *PHASHLEN. GNU hash | |
828 | // tables are an extension to ELF which are recognized by the GNU | |
829 | // dynamic linker. They are referenced using dynamic tag DT_GNU_HASH. | |
830 | // TARGET is the target. DYNSYMS is a vector with all the global | |
831 | // symbols which will be going into the dynamic symbol table. | |
832 | // LOCAL_DYNSYM_COUNT is the number of local symbols in the dynamic | |
833 | // symbol table. | |
834 | ||
835 | void | |
836 | Dynobj::create_gnu_hash_table(const Target* target, | |
837 | const std::vector<Symbol*>& dynsyms, | |
838 | unsigned int local_dynsym_count, | |
839 | unsigned char** pphash, | |
840 | unsigned int* phashlen) | |
841 | { | |
842 | const unsigned int count = dynsyms.size(); | |
843 | ||
844 | // Sort the dynamic symbols into two vectors. Symbols which we do | |
845 | // not want to put into the hash table we store into | |
846 | // UNHASHED_DYNSYMS. Symbols which we do want to store we put into | |
847 | // HASHED_DYNSYMS. DYNSYM_HASHVALS is parallel to HASHED_DYNSYMS, | |
848 | // and records the hash codes. | |
849 | ||
850 | std::vector<Symbol*> unhashed_dynsyms; | |
851 | unhashed_dynsyms.reserve(count); | |
852 | ||
853 | std::vector<Symbol*> hashed_dynsyms; | |
854 | hashed_dynsyms.reserve(count); | |
855 | ||
856 | std::vector<uint32_t> dynsym_hashvals; | |
857 | dynsym_hashvals.reserve(count); | |
858 | ||
859 | for (unsigned int i = 0; i < count; ++i) | |
860 | { | |
861 | Symbol* sym = dynsyms[i]; | |
862 | ||
863 | // FIXME: Should put on unhashed_dynsyms if the symbol is | |
864 | // hidden. | |
865 | if (sym->is_undefined()) | |
866 | unhashed_dynsyms.push_back(sym); | |
867 | else | |
868 | { | |
869 | hashed_dynsyms.push_back(sym); | |
870 | dynsym_hashvals.push_back(Dynobj::gnu_hash(sym->name())); | |
871 | } | |
872 | } | |
873 | ||
874 | // Put the unhashed symbols at the start of the global portion of | |
875 | // the dynamic symbol table. | |
876 | const unsigned int unhashed_count = unhashed_dynsyms.size(); | |
877 | unsigned int unhashed_dynsym_index = local_dynsym_count; | |
878 | for (unsigned int i = 0; i < unhashed_count; ++i) | |
879 | { | |
880 | unhashed_dynsyms[i]->set_dynsym_index(unhashed_dynsym_index); | |
881 | ++unhashed_dynsym_index; | |
882 | } | |
883 | ||
884 | // For the actual data generation we call out to a templatized | |
885 | // function. | |
886 | int size = target->get_size(); | |
887 | bool big_endian = target->is_big_endian(); | |
888 | if (size == 32) | |
889 | { | |
890 | if (big_endian) | |
891 | Dynobj::sized_create_gnu_hash_table<32, true>(hashed_dynsyms, | |
892 | dynsym_hashvals, | |
893 | unhashed_dynsym_index, | |
894 | pphash, | |
895 | phashlen); | |
896 | else | |
897 | Dynobj::sized_create_gnu_hash_table<32, false>(hashed_dynsyms, | |
898 | dynsym_hashvals, | |
899 | unhashed_dynsym_index, | |
900 | pphash, | |
901 | phashlen); | |
902 | } | |
903 | else if (size == 64) | |
904 | { | |
905 | if (big_endian) | |
906 | Dynobj::sized_create_gnu_hash_table<64, true>(hashed_dynsyms, | |
907 | dynsym_hashvals, | |
908 | unhashed_dynsym_index, | |
909 | pphash, | |
910 | phashlen); | |
911 | else | |
912 | Dynobj::sized_create_gnu_hash_table<64, false>(hashed_dynsyms, | |
913 | dynsym_hashvals, | |
914 | unhashed_dynsym_index, | |
915 | pphash, | |
916 | phashlen); | |
917 | } | |
918 | else | |
919 | gold_unreachable(); | |
920 | } | |
921 | ||
922 | // Create the actual data for a GNU hash table. This is just a copy | |
923 | // of the code from the old GNU linker. | |
924 | ||
925 | template<int size, bool big_endian> | |
926 | void | |
927 | Dynobj::sized_create_gnu_hash_table( | |
928 | const std::vector<Symbol*>& hashed_dynsyms, | |
929 | const std::vector<uint32_t>& dynsym_hashvals, | |
930 | unsigned int unhashed_dynsym_count, | |
931 | unsigned char** pphash, | |
932 | unsigned int* phashlen) | |
933 | { | |
934 | if (hashed_dynsyms.empty()) | |
935 | { | |
936 | // Special case for the empty hash table. | |
937 | unsigned int hashlen = 5 * 4 + size / 8; | |
938 | unsigned char* phash = new unsigned char[hashlen]; | |
939 | // One empty bucket. | |
940 | elfcpp::Swap<32, big_endian>::writeval(phash, 1); | |
941 | // Symbol index above unhashed symbols. | |
942 | elfcpp::Swap<32, big_endian>::writeval(phash + 4, unhashed_dynsym_count); | |
943 | // One word for bitmask. | |
944 | elfcpp::Swap<32, big_endian>::writeval(phash + 8, 1); | |
945 | // Only bloom filter. | |
946 | elfcpp::Swap<32, big_endian>::writeval(phash + 12, 0); | |
947 | // No valid hashes. | |
948 | elfcpp::Swap<size, big_endian>::writeval(phash + 16, 0); | |
949 | // No hashes in only bucket. | |
950 | elfcpp::Swap<32, big_endian>::writeval(phash + 16 + size / 8, 0); | |
951 | ||
952 | *phashlen = hashlen; | |
953 | *pphash = phash; | |
954 | ||
955 | return; | |
956 | } | |
957 | ||
958 | const unsigned int bucketcount = | |
959 | Dynobj::compute_bucket_count(dynsym_hashvals, true); | |
960 | ||
961 | const unsigned int nsyms = hashed_dynsyms.size(); | |
962 | ||
963 | uint32_t maskbitslog2 = 1; | |
964 | uint32_t x = nsyms >> 1; | |
965 | while (x != 0) | |
966 | { | |
967 | ++maskbitslog2; | |
968 | x >>= 1; | |
969 | } | |
970 | if (maskbitslog2 < 3) | |
971 | maskbitslog2 = 5; | |
972 | else if (((1U << (maskbitslog2 - 2)) & nsyms) != 0) | |
973 | maskbitslog2 += 3; | |
974 | else | |
975 | maskbitslog2 += 2; | |
976 | ||
977 | uint32_t shift1; | |
978 | if (size == 32) | |
979 | shift1 = 5; | |
980 | else | |
981 | { | |
982 | if (maskbitslog2 == 5) | |
983 | maskbitslog2 = 6; | |
984 | shift1 = 6; | |
985 | } | |
986 | uint32_t mask = (1U << shift1) - 1U; | |
987 | uint32_t shift2 = maskbitslog2; | |
988 | uint32_t maskbits = 1U << maskbitslog2; | |
989 | uint32_t maskwords = 1U << (maskbitslog2 - shift1); | |
990 | ||
991 | typedef typename elfcpp::Elf_types<size>::Elf_WXword Word; | |
992 | std::vector<Word> bitmask(maskwords); | |
993 | std::vector<uint32_t> counts(bucketcount); | |
994 | std::vector<uint32_t> indx(bucketcount); | |
995 | uint32_t symindx = unhashed_dynsym_count; | |
996 | ||
997 | // Count the number of times each hash bucket is used. | |
998 | for (unsigned int i = 0; i < nsyms; ++i) | |
999 | ++counts[dynsym_hashvals[i] % bucketcount]; | |
1000 | ||
1001 | unsigned int cnt = symindx; | |
1002 | for (unsigned int i = 0; i < bucketcount; ++i) | |
1003 | { | |
1004 | indx[i] = cnt; | |
1005 | cnt += counts[i]; | |
1006 | } | |
1007 | ||
1008 | unsigned int hashlen = (4 + bucketcount + nsyms) * 4; | |
1009 | hashlen += maskbits / 8; | |
1010 | unsigned char* phash = new unsigned char[hashlen]; | |
1011 | ||
1012 | elfcpp::Swap<32, big_endian>::writeval(phash, bucketcount); | |
1013 | elfcpp::Swap<32, big_endian>::writeval(phash + 4, symindx); | |
1014 | elfcpp::Swap<32, big_endian>::writeval(phash + 8, maskwords); | |
1015 | elfcpp::Swap<32, big_endian>::writeval(phash + 12, shift2); | |
1016 | ||
1017 | unsigned char* p = phash + 16 + maskbits / 8; | |
1018 | for (unsigned int i = 0; i < bucketcount; ++i) | |
1019 | { | |
1020 | if (counts[i] == 0) | |
1021 | elfcpp::Swap<32, big_endian>::writeval(p, 0); | |
1022 | else | |
1023 | elfcpp::Swap<32, big_endian>::writeval(p, indx[i]); | |
1024 | p += 4; | |
1025 | } | |
1026 | ||
1027 | for (unsigned int i = 0; i < nsyms; ++i) | |
1028 | { | |
1029 | Symbol* sym = hashed_dynsyms[i]; | |
1030 | uint32_t hashval = dynsym_hashvals[i]; | |
1031 | ||
1032 | unsigned int bucket = hashval % bucketcount; | |
1033 | unsigned int val = ((hashval >> shift1) | |
1034 | & ((maskbits >> shift1) - 1)); | |
1035 | bitmask[val] |= (static_cast<Word>(1U)) << (hashval & mask); | |
1036 | bitmask[val] |= (static_cast<Word>(1U)) << ((hashval >> shift2) & mask); | |
1037 | val = hashval & ~ 1U; | |
1038 | if (counts[bucket] == 1) | |
1039 | { | |
1040 | // Last element terminates the chain. | |
1041 | val |= 1; | |
1042 | } | |
1043 | elfcpp::Swap<32, big_endian>::writeval(p + (indx[bucket] - symindx) * 4, | |
1044 | val); | |
1045 | --counts[bucket]; | |
1046 | ||
1047 | sym->set_dynsym_index(indx[bucket]); | |
1048 | ++indx[bucket]; | |
1049 | } | |
1050 | ||
1051 | p = phash + 16; | |
1052 | for (unsigned int i = 0; i < maskwords; ++i) | |
1053 | { | |
1054 | elfcpp::Swap<size, big_endian>::writeval(p, bitmask[i]); | |
1055 | p += size / 8; | |
1056 | } | |
1057 | ||
1058 | *phashlen = hashlen; | |
1059 | *pphash = phash; | |
1060 | } | |
1061 | ||
dbe717ef ILT |
1062 | // Instantiate the templates we need. We could use the configure |
1063 | // script to restrict this to only the ones for implemented targets. | |
1064 | ||
1065 | template | |
1066 | class Sized_dynobj<32, false>; | |
1067 | ||
1068 | template | |
1069 | class Sized_dynobj<32, true>; | |
1070 | ||
1071 | template | |
1072 | class Sized_dynobj<64, false>; | |
1073 | ||
1074 | template | |
1075 | class Sized_dynobj<64, true>; | |
1076 | ||
1077 | } // End namespace gold. |