1 /* Plugin support for BFD. 2 Copyright (C) 2009-2018 Free Software Foundation, Inc. 3 4 This file is part of BFD, the Binary File Descriptor library. 5 6 This program is free software; you can redistribute it and/or modify 7 it under the terms of the GNU General Public License as published by 8 the Free Software Foundation; either version 3 of the License, or 9 (at your option) any later version. 10 11 This program is distributed in the hope that it will be useful, 12 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 GNU General Public License for more details. 15 16 You should have received a copy of the GNU General Public License 17 along with this program; if not, write to the Free Software 18 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, 19 MA 02110-1301, USA. */ 20 21 #include "sysdep.h" 22 #include "bfd.h" 23 24 #if BFD_SUPPORTS_PLUGINS 25 26 #include <assert.h> 27 #ifdef HAVE_DLFCN_H 28 #include <dlfcn.h> 29 #elif defined (HAVE_WINDOWS_H) 30 #include <windows.h> 31 #else 32 #error Unknown how to handle dynamic-load-libraries. 33 #endif 34 #include <stdarg.h> 35 #include "plugin-api.h" 36 #include "plugin.h" 37 #include "libbfd.h" 38 #include "libiberty.h" 39 #include <dirent.h> 40 41 #if !defined (HAVE_DLFCN_H) && defined (HAVE_WINDOWS_H) 42 43 #define RTLD_NOW 0 /* Dummy value. */ 44 45 static void * 46 dlopen (const char *file, int mode ATTRIBUTE_UNUSED) 47 { 48 return LoadLibrary (file); 49 } 50 51 static void * 52 dlsym (void *handle, const char *name) 53 { 54 return GetProcAddress (handle, name); 55 } 56 57 static int ATTRIBUTE_UNUSED 58 dlclose (void *handle) 59 { 60 FreeLibrary (handle); 61 return 0; 62 } 63 64 static const char * 65 dlerror (void) 66 { 67 return "Unable to load DLL."; 68 } 69 70 #endif /* !defined (HAVE_DLFCN_H) && defined (HAVE_WINDOWS_H) */ 71 72 #define bfd_plugin_close_and_cleanup _bfd_generic_close_and_cleanup 73 #define bfd_plugin_bfd_free_cached_info _bfd_generic_bfd_free_cached_info 74 #define bfd_plugin_new_section_hook _bfd_generic_new_section_hook 75 #define bfd_plugin_get_section_contents _bfd_generic_get_section_contents 76 #define bfd_plugin_get_section_contents_in_window _bfd_generic_get_section_contents_in_window 77 #define bfd_plugin_bfd_copy_private_header_data _bfd_generic_bfd_copy_private_header_data 78 #define bfd_plugin_bfd_merge_private_bfd_data _bfd_generic_bfd_merge_private_bfd_data 79 #define bfd_plugin_bfd_copy_private_header_data _bfd_generic_bfd_copy_private_header_data 80 #define bfd_plugin_bfd_set_private_flags _bfd_generic_bfd_set_private_flags 81 #define bfd_plugin_core_file_matches_executable_p generic_core_file_matches_executable_p 82 #define bfd_plugin_bfd_is_local_label_name _bfd_nosymbols_bfd_is_local_label_name 83 #define bfd_plugin_bfd_is_target_special_symbol ((bfd_boolean (*) (bfd *, asymbol *)) bfd_false) 84 #define bfd_plugin_get_lineno _bfd_nosymbols_get_lineno 85 #define bfd_plugin_find_nearest_line _bfd_nosymbols_find_nearest_line 86 #define bfd_plugin_find_line _bfd_nosymbols_find_line 87 #define bfd_plugin_find_inliner_info _bfd_nosymbols_find_inliner_info 88 #define bfd_plugin_get_symbol_version_string _bfd_nosymbols_get_symbol_version_string 89 #define bfd_plugin_bfd_make_debug_symbol _bfd_nosymbols_bfd_make_debug_symbol 90 #define bfd_plugin_read_minisymbols _bfd_generic_read_minisymbols 91 #define bfd_plugin_minisymbol_to_symbol _bfd_generic_minisymbol_to_symbol 92 #define bfd_plugin_set_arch_mach bfd_default_set_arch_mach 93 #define bfd_plugin_set_section_contents _bfd_generic_set_section_contents 94 #define bfd_plugin_bfd_get_relocated_section_contents bfd_generic_get_relocated_section_contents 95 #define bfd_plugin_bfd_relax_section bfd_generic_relax_section 96 #define bfd_plugin_bfd_link_hash_table_create _bfd_generic_link_hash_table_create 97 #define bfd_plugin_bfd_link_add_symbols _bfd_generic_link_add_symbols 98 #define bfd_plugin_bfd_link_just_syms _bfd_generic_link_just_syms 99 #define bfd_plugin_bfd_final_link _bfd_generic_final_link 100 #define bfd_plugin_bfd_link_split_section _bfd_generic_link_split_section 101 #define bfd_plugin_bfd_gc_sections bfd_generic_gc_sections 102 #define bfd_plugin_bfd_lookup_section_flags bfd_generic_lookup_section_flags 103 #define bfd_plugin_bfd_merge_sections bfd_generic_merge_sections 104 #define bfd_plugin_bfd_is_group_section bfd_generic_is_group_section 105 #define bfd_plugin_bfd_discard_group bfd_generic_discard_group 106 #define bfd_plugin_section_already_linked _bfd_generic_section_already_linked 107 #define bfd_plugin_bfd_define_common_symbol bfd_generic_define_common_symbol 108 #define bfd_plugin_bfd_define_start_stop bfd_generic_define_start_stop 109 #define bfd_plugin_bfd_copy_link_hash_symbol_type _bfd_generic_copy_link_hash_symbol_type 110 #define bfd_plugin_bfd_link_check_relocs _bfd_generic_link_check_relocs 111 112 static enum ld_plugin_status 113 message (int level ATTRIBUTE_UNUSED, 114 const char * format, ...) 115 { 116 va_list args; 117 va_start (args, format); 118 printf ("bfd plugin: "); 119 vprintf (format, args); 120 putchar ('\n'); 121 va_end (args); 122 return LDPS_OK; 123 } 124 125 /* Register a claim-file handler. */ 126 static ld_plugin_claim_file_handler claim_file; 127 128 static enum ld_plugin_status 129 register_claim_file (ld_plugin_claim_file_handler handler) 130 { 131 claim_file = handler; 132 return LDPS_OK; 133 } 134 135 static enum ld_plugin_status 136 add_symbols (void * handle, 137 int nsyms, 138 const struct ld_plugin_symbol * syms) 139 { 140 bfd *abfd = handle; 141 struct plugin_data_struct *plugin_data = 142 bfd_alloc (abfd, sizeof (plugin_data_struct)); 143 144 plugin_data->nsyms = nsyms; 145 plugin_data->syms = syms; 146 147 if (nsyms != 0) 148 abfd->flags |= HAS_SYMS; 149 150 abfd->tdata.plugin_data = plugin_data; 151 return LDPS_OK; 152 } 153 154 static const char *plugin_program_name; 155 156 void 157 bfd_plugin_set_program_name (const char *program_name) 158 { 159 plugin_program_name = program_name; 160 } 161 162 int 163 bfd_plugin_open_input (bfd *ibfd, struct ld_plugin_input_file *file) 164 { 165 bfd *iobfd; 166 167 iobfd = ibfd; 168 if (ibfd->my_archive && !bfd_is_thin_archive (ibfd->my_archive)) 169 iobfd = ibfd->my_archive; 170 file->name = iobfd->filename; 171 172 if (!iobfd->iostream && !bfd_open_file (iobfd)) 173 return 0; 174 175 file->fd = fileno ((FILE *) iobfd->iostream); 176 177 if (iobfd == ibfd) 178 { 179 struct stat stat_buf; 180 if (fstat (file->fd, &stat_buf)) 181 return 0; 182 file->offset = 0; 183 file->filesize = stat_buf.st_size; 184 } 185 else 186 { 187 file->offset = ibfd->origin; 188 file->filesize = arelt_size (ibfd); 189 } 190 return 1; 191 } 192 193 static int 194 try_claim (bfd *abfd) 195 { 196 int claimed = 0; 197 struct ld_plugin_input_file file; 198 199 if (!bfd_plugin_open_input (abfd, &file)) 200 return 0; 201 file.handle = abfd; 202 off_t cur_offset = lseek (file.fd, 0, SEEK_CUR); 203 claim_file (&file, &claimed); 204 lseek (file.fd, cur_offset, SEEK_SET); 205 return claimed; 206 } 207 208 static int 209 try_load_plugin (const char *pname, bfd *abfd, int *has_plugin_p) 210 { 211 void *plugin_handle; 212 struct ld_plugin_tv tv[4]; 213 int i; 214 ld_plugin_onload onload; 215 enum ld_plugin_status status; 216 217 *has_plugin_p = 0; 218 219 plugin_handle = dlopen (pname, RTLD_NOW); 220 if (!plugin_handle) 221 { 222 _bfd_error_handler ("%s\n", dlerror ()); 223 return 0; 224 } 225 226 onload = dlsym (plugin_handle, "onload"); 227 if (!onload) 228 goto err; 229 230 i = 0; 231 tv[i].tv_tag = LDPT_MESSAGE; 232 tv[i].tv_u.tv_message = message; 233 234 ++i; 235 tv[i].tv_tag = LDPT_REGISTER_CLAIM_FILE_HOOK; 236 tv[i].tv_u.tv_register_claim_file = register_claim_file; 237 238 ++i; 239 tv[i].tv_tag = LDPT_ADD_SYMBOLS; 240 tv[i].tv_u.tv_add_symbols = add_symbols; 241 242 ++i; 243 tv[i].tv_tag = LDPT_NULL; 244 tv[i].tv_u.tv_val = 0; 245 246 status = (*onload)(tv); 247 248 if (status != LDPS_OK) 249 goto err; 250 251 *has_plugin_p = 1; 252 253 abfd->plugin_format = bfd_plugin_no; 254 255 if (!claim_file) 256 goto err; 257 258 if (!try_claim (abfd)) 259 goto err; 260 261 abfd->plugin_format = bfd_plugin_yes; 262 263 return 1; 264 265 err: 266 return 0; 267 } 268 269 /* There may be plugin libraries in lib/bfd-plugins. */ 270 271 static int has_plugin = -1; 272 273 static const bfd_target *(*ld_plugin_object_p) (bfd *); 274 275 static const char *plugin_name; 276 277 void 278 bfd_plugin_set_plugin (const char *p) 279 { 280 plugin_name = p; 281 has_plugin = p != NULL; 282 } 283 284 /* Return TRUE if a plugin library is used. */ 285 286 bfd_boolean 287 bfd_plugin_specified_p (void) 288 { 289 return has_plugin > 0; 290 } 291 292 /* Return TRUE if ABFD can be claimed by linker LTO plugin. */ 293 294 bfd_boolean 295 bfd_link_plugin_object_p (bfd *abfd) 296 { 297 if (ld_plugin_object_p) 298 return ld_plugin_object_p (abfd) != NULL; 299 return FALSE; 300 } 301 302 extern const bfd_target plugin_vec; 303 304 /* Return TRUE if TARGET is a pointer to plugin_vec. */ 305 306 bfd_boolean 307 bfd_plugin_target_p (const bfd_target *target) 308 { 309 return target == &plugin_vec; 310 } 311 312 /* Register OBJECT_P to be used by bfd_plugin_object_p. */ 313 314 void 315 register_ld_plugin_object_p (const bfd_target *(*object_p) (bfd *)) 316 { 317 ld_plugin_object_p = object_p; 318 } 319 320 static int 321 load_plugin (bfd *abfd) 322 { 323 char *plugin_dir; 324 char *p; 325 DIR *d; 326 struct dirent *ent; 327 int found = 0; 328 329 if (!has_plugin) 330 return found; 331 332 if (plugin_name) 333 return try_load_plugin (plugin_name, abfd, &has_plugin); 334 335 if (plugin_program_name == NULL) 336 return found; 337 338 plugin_dir = concat (BINDIR, "/../lib/bfd-plugins", NULL); 339 p = make_relative_prefix (plugin_program_name, 340 BINDIR, 341 plugin_dir); 342 free (plugin_dir); 343 plugin_dir = NULL; 344 345 d = opendir (p); 346 if (!d) 347 goto out; 348 349 while ((ent = readdir (d))) 350 { 351 char *full_name; 352 struct stat s; 353 int valid_plugin; 354 355 full_name = concat (p, "/", ent->d_name, NULL); 356 if (stat(full_name, &s) == 0 && S_ISREG (s.st_mode)) 357 found = try_load_plugin (full_name, abfd, &valid_plugin); 358 if (has_plugin <= 0) 359 has_plugin = valid_plugin; 360 free (full_name); 361 if (found) 362 break; 363 } 364 365 out: 366 free (p); 367 if (d) 368 closedir (d); 369 370 return found; 371 } 372 373 374 static const bfd_target * 375 bfd_plugin_object_p (bfd *abfd) 376 { 377 if (ld_plugin_object_p) 378 return ld_plugin_object_p (abfd); 379 380 if (abfd->plugin_format == bfd_plugin_unknown && !load_plugin (abfd)) 381 return NULL; 382 383 return abfd->plugin_format == bfd_plugin_yes ? abfd->xvec : NULL; 384 } 385 386 /* Copy any private info we understand from the input bfd 387 to the output bfd. */ 388 389 static bfd_boolean 390 bfd_plugin_bfd_copy_private_bfd_data (bfd *ibfd ATTRIBUTE_UNUSED, 391 bfd *obfd ATTRIBUTE_UNUSED) 392 { 393 BFD_ASSERT (0); 394 return TRUE; 395 } 396 397 /* Copy any private info we understand from the input section 398 to the output section. */ 399 400 static bfd_boolean 401 bfd_plugin_bfd_copy_private_section_data (bfd *ibfd ATTRIBUTE_UNUSED, 402 asection *isection ATTRIBUTE_UNUSED, 403 bfd *obfd ATTRIBUTE_UNUSED, 404 asection *osection ATTRIBUTE_UNUSED) 405 { 406 BFD_ASSERT (0); 407 return TRUE; 408 } 409 410 /* Copy any private info we understand from the input symbol 411 to the output symbol. */ 412 413 static bfd_boolean 414 bfd_plugin_bfd_copy_private_symbol_data (bfd *ibfd ATTRIBUTE_UNUSED, 415 asymbol *isymbol ATTRIBUTE_UNUSED, 416 bfd *obfd ATTRIBUTE_UNUSED, 417 asymbol *osymbol ATTRIBUTE_UNUSED) 418 { 419 BFD_ASSERT (0); 420 return TRUE; 421 } 422 423 static bfd_boolean 424 bfd_plugin_bfd_print_private_bfd_data (bfd *abfd ATTRIBUTE_UNUSED, PTR ptr ATTRIBUTE_UNUSED) 425 { 426 BFD_ASSERT (0); 427 return TRUE; 428 } 429 430 static char * 431 bfd_plugin_core_file_failing_command (bfd *abfd ATTRIBUTE_UNUSED) 432 { 433 BFD_ASSERT (0); 434 return NULL; 435 } 436 437 static int 438 bfd_plugin_core_file_failing_signal (bfd *abfd ATTRIBUTE_UNUSED) 439 { 440 BFD_ASSERT (0); 441 return 0; 442 } 443 444 static int 445 bfd_plugin_core_file_pid (bfd *abfd ATTRIBUTE_UNUSED) 446 { 447 BFD_ASSERT (0); 448 return 0; 449 } 450 451 static long 452 bfd_plugin_get_symtab_upper_bound (bfd *abfd) 453 { 454 struct plugin_data_struct *plugin_data = abfd->tdata.plugin_data; 455 long nsyms = plugin_data->nsyms; 456 457 BFD_ASSERT (nsyms >= 0); 458 459 return ((nsyms + 1) * sizeof (asymbol *)); 460 } 461 462 static flagword 463 convert_flags (const struct ld_plugin_symbol *sym) 464 { 465 switch (sym->def) 466 { 467 case LDPK_DEF: 468 case LDPK_COMMON: 469 case LDPK_UNDEF: 470 return BSF_GLOBAL; 471 472 case LDPK_WEAKUNDEF: 473 case LDPK_WEAKDEF: 474 return BSF_GLOBAL | BSF_WEAK; 475 476 default: 477 BFD_ASSERT (0); 478 return 0; 479 } 480 } 481 482 static long 483 bfd_plugin_canonicalize_symtab (bfd *abfd, 484 asymbol **alocation) 485 { 486 struct plugin_data_struct *plugin_data = abfd->tdata.plugin_data; 487 long nsyms = plugin_data->nsyms; 488 const struct ld_plugin_symbol *syms = plugin_data->syms; 489 static asection fake_section; 490 static asection fake_common_section; 491 int i; 492 493 fake_section.name = ".text"; 494 fake_common_section.flags = SEC_IS_COMMON; 495 496 for (i = 0; i < nsyms; i++) 497 { 498 asymbol *s = bfd_alloc (abfd, sizeof (asymbol)); 499 500 BFD_ASSERT (s); 501 alocation[i] = s; 502 503 s->the_bfd = abfd; 504 s->name = syms[i].name; 505 s->value = 0; 506 s->flags = convert_flags (&syms[i]); 507 switch (syms[i].def) 508 { 509 case LDPK_COMMON: 510 s->section = &fake_common_section; 511 break; 512 case LDPK_UNDEF: 513 case LDPK_WEAKUNDEF: 514 s->section = bfd_und_section_ptr; 515 break; 516 case LDPK_DEF: 517 case LDPK_WEAKDEF: 518 s->section = &fake_section; 519 break; 520 default: 521 BFD_ASSERT (0); 522 } 523 524 s->udata.p = (void *) &syms[i]; 525 } 526 527 return nsyms; 528 } 529 530 static void 531 bfd_plugin_print_symbol (bfd *abfd ATTRIBUTE_UNUSED, 532 PTR afile ATTRIBUTE_UNUSED, 533 asymbol *symbol ATTRIBUTE_UNUSED, 534 bfd_print_symbol_type how ATTRIBUTE_UNUSED) 535 { 536 BFD_ASSERT (0); 537 } 538 539 static void 540 bfd_plugin_get_symbol_info (bfd *abfd ATTRIBUTE_UNUSED, 541 asymbol *symbol, 542 symbol_info *ret) 543 { 544 bfd_symbol_info (symbol, ret); 545 } 546 547 /* Make an empty symbol. */ 548 549 static asymbol * 550 bfd_plugin_make_empty_symbol (bfd *abfd) 551 { 552 asymbol *new_symbol = bfd_zalloc (abfd, sizeof (asymbol)); 553 if (new_symbol == NULL) 554 return new_symbol; 555 new_symbol->the_bfd = abfd; 556 return new_symbol; 557 } 558 559 static int 560 bfd_plugin_sizeof_headers (bfd *a ATTRIBUTE_UNUSED, 561 struct bfd_link_info *info ATTRIBUTE_UNUSED) 562 { 563 BFD_ASSERT (0); 564 return 0; 565 } 566 567 const bfd_target plugin_vec = 568 { 569 "plugin", /* Name. */ 570 bfd_target_unknown_flavour, 571 BFD_ENDIAN_LITTLE, /* Target byte order. */ 572 BFD_ENDIAN_LITTLE, /* Target headers byte order. */ 573 (HAS_RELOC | EXEC_P | /* Object flags. */ 574 HAS_LINENO | HAS_DEBUG | 575 HAS_SYMS | HAS_LOCALS | DYNAMIC | WP_TEXT | D_PAGED), 576 (SEC_CODE | SEC_DATA | SEC_ROM | SEC_HAS_CONTENTS 577 | SEC_ALLOC | SEC_LOAD | SEC_RELOC), /* Section flags. */ 578 0, /* symbol_leading_char. */ 579 '/', /* ar_pad_char. */ 580 15, /* ar_max_namelen. */ 581 255, /* match priority. */ 582 583 bfd_getl64, bfd_getl_signed_64, bfd_putl64, 584 bfd_getl32, bfd_getl_signed_32, bfd_putl32, 585 bfd_getl16, bfd_getl_signed_16, bfd_putl16, /* data */ 586 bfd_getl64, bfd_getl_signed_64, bfd_putl64, 587 bfd_getl32, bfd_getl_signed_32, bfd_putl32, 588 bfd_getl16, bfd_getl_signed_16, bfd_putl16, /* hdrs */ 589 590 { /* bfd_check_format. */ 591 _bfd_dummy_target, 592 bfd_plugin_object_p, 593 bfd_generic_archive_p, 594 _bfd_dummy_target 595 }, 596 { /* bfd_set_format. */ 597 bfd_false, 598 bfd_false, 599 _bfd_generic_mkarchive, 600 bfd_false, 601 }, 602 { /* bfd_write_contents. */ 603 bfd_false, 604 bfd_false, 605 _bfd_write_archive_contents, 606 bfd_false, 607 }, 608 609 BFD_JUMP_TABLE_GENERIC (bfd_plugin), 610 BFD_JUMP_TABLE_COPY (bfd_plugin), 611 BFD_JUMP_TABLE_CORE (bfd_plugin), 612 #ifdef USE_64_BIT_ARCHIVE 613 BFD_JUMP_TABLE_ARCHIVE (_bfd_archive_64_bit), 614 #else 615 BFD_JUMP_TABLE_ARCHIVE (_bfd_archive_coff), 616 #endif 617 BFD_JUMP_TABLE_SYMBOLS (bfd_plugin), 618 BFD_JUMP_TABLE_RELOCS (_bfd_norelocs), 619 BFD_JUMP_TABLE_WRITE (bfd_plugin), 620 BFD_JUMP_TABLE_LINK (bfd_plugin), 621 BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic), 622 623 NULL, 624 625 NULL /* backend_data. */ 626 }; 627 #endif /* BFD_SUPPORTS_PLUGIN */ 628