| 1 | /* Plugin control for the GNU linker. |
| 2 | Copyright (C) 2010-2014 Free Software Foundation, Inc. |
| 3 | |
| 4 | This file is part of the GNU Binutils. |
| 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 "libiberty.h" |
| 23 | #include "bfd.h" |
| 24 | #include "bfdlink.h" |
| 25 | #include "bfdver.h" |
| 26 | #include "ld.h" |
| 27 | #include "ldmain.h" |
| 28 | #include "ldmisc.h" |
| 29 | #include "ldexp.h" |
| 30 | #include "ldlang.h" |
| 31 | #include "ldfile.h" |
| 32 | #include "plugin.h" |
| 33 | #include "plugin-api.h" |
| 34 | #include "elf-bfd.h" |
| 35 | #if !defined (HAVE_DLFCN_H) && defined (HAVE_WINDOWS_H) |
| 36 | #include <windows.h> |
| 37 | #endif |
| 38 | |
| 39 | /* Report plugin symbols. */ |
| 40 | bfd_boolean report_plugin_symbols; |
| 41 | |
| 42 | /* The suffix to append to the name of the real (claimed) object file |
| 43 | when generating a dummy BFD to hold the IR symbols sent from the |
| 44 | plugin. For cosmetic use only; appears in maps, crefs etc. */ |
| 45 | #define IRONLY_SUFFIX " (symbol from plugin)" |
| 46 | |
| 47 | /* Stores a single argument passed to a plugin. */ |
| 48 | typedef struct plugin_arg |
| 49 | { |
| 50 | struct plugin_arg *next; |
| 51 | const char *arg; |
| 52 | } plugin_arg_t; |
| 53 | |
| 54 | /* Holds all details of a single plugin. */ |
| 55 | typedef struct plugin |
| 56 | { |
| 57 | /* Next on the list of plugins, or NULL at end of chain. */ |
| 58 | struct plugin *next; |
| 59 | /* The argument string given to --plugin. */ |
| 60 | const char *name; |
| 61 | /* The shared library handle returned by dlopen. */ |
| 62 | void *dlhandle; |
| 63 | /* The list of argument string given to --plugin-opt. */ |
| 64 | plugin_arg_t *args; |
| 65 | /* Number of args in the list, for convenience. */ |
| 66 | size_t n_args; |
| 67 | /* The plugin's event handlers. */ |
| 68 | ld_plugin_claim_file_handler claim_file_handler; |
| 69 | ld_plugin_all_symbols_read_handler all_symbols_read_handler; |
| 70 | ld_plugin_cleanup_handler cleanup_handler; |
| 71 | /* TRUE if the cleanup handlers have been called. */ |
| 72 | bfd_boolean cleanup_done; |
| 73 | } plugin_t; |
| 74 | |
| 75 | /* The master list of all plugins. */ |
| 76 | static plugin_t *plugins_list = NULL; |
| 77 | |
| 78 | /* We keep a tail pointer for easy linking on the end. */ |
| 79 | static plugin_t **plugins_tail_chain_ptr = &plugins_list; |
| 80 | |
| 81 | /* The last plugin added to the list, for receiving args. */ |
| 82 | static plugin_t *last_plugin = NULL; |
| 83 | |
| 84 | /* The tail of the arg chain of the last plugin added to the list. */ |
| 85 | static plugin_arg_t **last_plugin_args_tail_chain_ptr = NULL; |
| 86 | |
| 87 | /* The plugin which is currently having a callback executed. */ |
| 88 | static plugin_t *called_plugin = NULL; |
| 89 | |
| 90 | /* Last plugin to cause an error, if any. */ |
| 91 | static const char *error_plugin = NULL; |
| 92 | |
| 93 | /* State of linker "notice" interface before we poked at it. */ |
| 94 | static bfd_boolean orig_notice_all; |
| 95 | |
| 96 | /* Original linker callbacks, and the plugin version. */ |
| 97 | static const struct bfd_link_callbacks *orig_callbacks; |
| 98 | static struct bfd_link_callbacks plugin_callbacks; |
| 99 | |
| 100 | /* Set at all symbols read time, to avoid recursively offering the plugin |
| 101 | its own newly-added input files and libs to claim. */ |
| 102 | bfd_boolean no_more_claiming = FALSE; |
| 103 | |
| 104 | /* List of tags to set in the constant leading part of the tv array. */ |
| 105 | static const enum ld_plugin_tag tv_header_tags[] = |
| 106 | { |
| 107 | LDPT_MESSAGE, |
| 108 | LDPT_API_VERSION, |
| 109 | LDPT_GNU_LD_VERSION, |
| 110 | LDPT_LINKER_OUTPUT, |
| 111 | LDPT_OUTPUT_NAME, |
| 112 | LDPT_REGISTER_CLAIM_FILE_HOOK, |
| 113 | LDPT_REGISTER_ALL_SYMBOLS_READ_HOOK, |
| 114 | LDPT_REGISTER_CLEANUP_HOOK, |
| 115 | LDPT_ADD_SYMBOLS, |
| 116 | LDPT_GET_INPUT_FILE, |
| 117 | LDPT_RELEASE_INPUT_FILE, |
| 118 | LDPT_GET_SYMBOLS, |
| 119 | LDPT_GET_SYMBOLS_V2, |
| 120 | LDPT_ADD_INPUT_FILE, |
| 121 | LDPT_ADD_INPUT_LIBRARY, |
| 122 | LDPT_SET_EXTRA_LIBRARY_PATH |
| 123 | }; |
| 124 | |
| 125 | /* How many entries in the constant leading part of the tv array. */ |
| 126 | static const size_t tv_header_size = ARRAY_SIZE (tv_header_tags); |
| 127 | |
| 128 | /* Forward references. */ |
| 129 | static bfd_boolean plugin_notice (struct bfd_link_info *, |
| 130 | struct bfd_link_hash_entry *, bfd *, |
| 131 | asection *, bfd_vma, flagword, const char *); |
| 132 | |
| 133 | #if !defined (HAVE_DLFCN_H) && defined (HAVE_WINDOWS_H) |
| 134 | |
| 135 | #define RTLD_NOW 0 /* Dummy value. */ |
| 136 | |
| 137 | static void * |
| 138 | dlopen (const char *file, int mode ATTRIBUTE_UNUSED) |
| 139 | { |
| 140 | return LoadLibrary (file); |
| 141 | } |
| 142 | |
| 143 | static void * |
| 144 | dlsym (void *handle, const char *name) |
| 145 | { |
| 146 | return GetProcAddress (handle, name); |
| 147 | } |
| 148 | |
| 149 | static int |
| 150 | dlclose (void *handle) |
| 151 | { |
| 152 | FreeLibrary (handle); |
| 153 | return 0; |
| 154 | } |
| 155 | |
| 156 | #endif /* !defined (HAVE_DLFCN_H) && defined (HAVE_WINDOWS_H) */ |
| 157 | |
| 158 | #ifndef HAVE_DLFCN_H |
| 159 | static const char * |
| 160 | dlerror (void) |
| 161 | { |
| 162 | return ""; |
| 163 | } |
| 164 | #endif |
| 165 | |
| 166 | /* Helper function for exiting with error status. */ |
| 167 | static int |
| 168 | set_plugin_error (const char *plugin) |
| 169 | { |
| 170 | error_plugin = plugin; |
| 171 | return -1; |
| 172 | } |
| 173 | |
| 174 | /* Test if an error occurred. */ |
| 175 | static bfd_boolean |
| 176 | plugin_error_p (void) |
| 177 | { |
| 178 | return error_plugin != NULL; |
| 179 | } |
| 180 | |
| 181 | /* Return name of plugin which caused an error if any. */ |
| 182 | const char * |
| 183 | plugin_error_plugin (void) |
| 184 | { |
| 185 | return error_plugin ? error_plugin : _("<no plugin>"); |
| 186 | } |
| 187 | |
| 188 | /* Handle -plugin arg: find and load plugin, or return error. */ |
| 189 | void |
| 190 | plugin_opt_plugin (const char *plugin) |
| 191 | { |
| 192 | plugin_t *newplug; |
| 193 | |
| 194 | newplug = xmalloc (sizeof *newplug); |
| 195 | memset (newplug, 0, sizeof *newplug); |
| 196 | newplug->name = plugin; |
| 197 | newplug->dlhandle = dlopen (plugin, RTLD_NOW); |
| 198 | if (!newplug->dlhandle) |
| 199 | einfo (_("%P%F: %s: error loading plugin: %s\n"), plugin, dlerror ()); |
| 200 | |
| 201 | /* Chain on end, so when we run list it is in command-line order. */ |
| 202 | *plugins_tail_chain_ptr = newplug; |
| 203 | plugins_tail_chain_ptr = &newplug->next; |
| 204 | |
| 205 | /* Record it as current plugin for receiving args. */ |
| 206 | last_plugin = newplug; |
| 207 | last_plugin_args_tail_chain_ptr = &newplug->args; |
| 208 | } |
| 209 | |
| 210 | /* Accumulate option arguments for last-loaded plugin, or return |
| 211 | error if none. */ |
| 212 | int |
| 213 | plugin_opt_plugin_arg (const char *arg) |
| 214 | { |
| 215 | plugin_arg_t *newarg; |
| 216 | |
| 217 | if (!last_plugin) |
| 218 | return set_plugin_error (_("<no plugin>")); |
| 219 | |
| 220 | newarg = xmalloc (sizeof *newarg); |
| 221 | newarg->arg = arg; |
| 222 | newarg->next = NULL; |
| 223 | |
| 224 | /* Chain on end to preserve command-line order. */ |
| 225 | *last_plugin_args_tail_chain_ptr = newarg; |
| 226 | last_plugin_args_tail_chain_ptr = &newarg->next; |
| 227 | last_plugin->n_args++; |
| 228 | return 0; |
| 229 | } |
| 230 | |
| 231 | /* Create a dummy BFD. */ |
| 232 | bfd * |
| 233 | plugin_get_ir_dummy_bfd (const char *name, bfd *srctemplate) |
| 234 | { |
| 235 | bfd *abfd; |
| 236 | |
| 237 | bfd_use_reserved_id = 1; |
| 238 | abfd = bfd_create (concat (name, IRONLY_SUFFIX, (const char *) NULL), |
| 239 | srctemplate); |
| 240 | if (abfd != NULL) |
| 241 | { |
| 242 | abfd->flags |= BFD_LINKER_CREATED | BFD_PLUGIN; |
| 243 | bfd_set_arch_info (abfd, bfd_get_arch_info (srctemplate)); |
| 244 | bfd_set_gp_size (abfd, bfd_get_gp_size (srctemplate)); |
| 245 | if (bfd_make_writable (abfd) |
| 246 | && bfd_copy_private_bfd_data (srctemplate, abfd)) |
| 247 | { |
| 248 | flagword flags; |
| 249 | |
| 250 | /* Create section to own the symbols. */ |
| 251 | flags = (SEC_CODE | SEC_HAS_CONTENTS | SEC_READONLY |
| 252 | | SEC_ALLOC | SEC_LOAD | SEC_KEEP | SEC_EXCLUDE); |
| 253 | if (bfd_make_section_anyway_with_flags (abfd, ".text", flags)) |
| 254 | return abfd; |
| 255 | } |
| 256 | } |
| 257 | einfo (_("could not create dummy IR bfd: %F%E\n")); |
| 258 | return NULL; |
| 259 | } |
| 260 | |
| 261 | /* Check if the BFD passed in is an IR dummy object file. */ |
| 262 | static bfd_boolean |
| 263 | is_ir_dummy_bfd (const bfd *abfd) |
| 264 | { |
| 265 | /* ABFD can sometimes legitimately be NULL, e.g. when called from one |
| 266 | of the linker callbacks for a symbol in the *ABS* or *UND* sections. |
| 267 | Likewise, the usrdata field may be NULL if ABFD was added by the |
| 268 | backend without a corresponding input statement, as happens e.g. |
| 269 | when processing DT_NEEDED dependencies. */ |
| 270 | return (abfd |
| 271 | && abfd->usrdata |
| 272 | && ((lang_input_statement_type *)(abfd->usrdata))->flags.claimed); |
| 273 | } |
| 274 | |
| 275 | /* Helpers to convert between BFD and GOLD symbol formats. */ |
| 276 | static enum ld_plugin_status |
| 277 | asymbol_from_plugin_symbol (bfd *abfd, asymbol *asym, |
| 278 | const struct ld_plugin_symbol *ldsym) |
| 279 | { |
| 280 | flagword flags = BSF_NO_FLAGS; |
| 281 | struct bfd_section *section; |
| 282 | |
| 283 | asym->the_bfd = abfd; |
| 284 | asym->name = (ldsym->version |
| 285 | ? concat (ldsym->name, "@", ldsym->version, (const char *) NULL) |
| 286 | : ldsym->name); |
| 287 | asym->value = 0; |
| 288 | switch (ldsym->def) |
| 289 | { |
| 290 | case LDPK_WEAKDEF: |
| 291 | flags = BSF_WEAK; |
| 292 | /* FALLTHRU */ |
| 293 | case LDPK_DEF: |
| 294 | flags |= BSF_GLOBAL; |
| 295 | if (ldsym->comdat_key) |
| 296 | { |
| 297 | char *name = concat (".gnu.linkonce.t.", ldsym->comdat_key, |
| 298 | (const char *) NULL); |
| 299 | section = bfd_get_section_by_name (abfd, name); |
| 300 | if (section != NULL) |
| 301 | free (name); |
| 302 | else |
| 303 | { |
| 304 | flagword sflags; |
| 305 | |
| 306 | sflags = (SEC_CODE | SEC_HAS_CONTENTS | SEC_READONLY |
| 307 | | SEC_ALLOC | SEC_LOAD | SEC_KEEP | SEC_EXCLUDE |
| 308 | | SEC_LINK_ONCE | SEC_LINK_DUPLICATES_DISCARD); |
| 309 | section = bfd_make_section_anyway_with_flags (abfd, name, sflags); |
| 310 | if (section == NULL) |
| 311 | return LDPS_ERR; |
| 312 | } |
| 313 | } |
| 314 | else |
| 315 | section = bfd_get_section_by_name (abfd, ".text"); |
| 316 | break; |
| 317 | |
| 318 | case LDPK_WEAKUNDEF: |
| 319 | flags = BSF_WEAK; |
| 320 | /* FALLTHRU */ |
| 321 | case LDPK_UNDEF: |
| 322 | section = bfd_und_section_ptr; |
| 323 | break; |
| 324 | |
| 325 | case LDPK_COMMON: |
| 326 | flags = BSF_GLOBAL; |
| 327 | section = bfd_com_section_ptr; |
| 328 | asym->value = ldsym->size; |
| 329 | /* For ELF targets, set alignment of common symbol to 1. */ |
| 330 | if (bfd_get_flavour (abfd) == bfd_target_elf_flavour) |
| 331 | { |
| 332 | ((elf_symbol_type *) asym)->internal_elf_sym.st_shndx = SHN_COMMON; |
| 333 | ((elf_symbol_type *) asym)->internal_elf_sym.st_value = 1; |
| 334 | } |
| 335 | break; |
| 336 | |
| 337 | default: |
| 338 | return LDPS_ERR; |
| 339 | } |
| 340 | asym->flags = flags; |
| 341 | asym->section = section; |
| 342 | |
| 343 | /* Visibility only applies on ELF targets. */ |
| 344 | if (bfd_get_flavour (abfd) == bfd_target_elf_flavour) |
| 345 | { |
| 346 | elf_symbol_type *elfsym = elf_symbol_from (abfd, asym); |
| 347 | unsigned char visibility; |
| 348 | |
| 349 | if (!elfsym) |
| 350 | einfo (_("%P%F: %s: non-ELF symbol in ELF BFD!\n"), asym->name); |
| 351 | switch (ldsym->visibility) |
| 352 | { |
| 353 | default: |
| 354 | einfo (_("%P%F: unknown ELF symbol visibility: %d!\n"), |
| 355 | ldsym->visibility); |
| 356 | case LDPV_DEFAULT: |
| 357 | visibility = STV_DEFAULT; |
| 358 | break; |
| 359 | case LDPV_PROTECTED: |
| 360 | visibility = STV_PROTECTED; |
| 361 | break; |
| 362 | case LDPV_INTERNAL: |
| 363 | visibility = STV_INTERNAL; |
| 364 | break; |
| 365 | case LDPV_HIDDEN: |
| 366 | visibility = STV_HIDDEN; |
| 367 | break; |
| 368 | } |
| 369 | elfsym->internal_elf_sym.st_other |
| 370 | = (visibility | (elfsym->internal_elf_sym.st_other |
| 371 | & ~ELF_ST_VISIBILITY (-1))); |
| 372 | } |
| 373 | |
| 374 | return LDPS_OK; |
| 375 | } |
| 376 | |
| 377 | /* Register a claim-file handler. */ |
| 378 | static enum ld_plugin_status |
| 379 | register_claim_file (ld_plugin_claim_file_handler handler) |
| 380 | { |
| 381 | ASSERT (called_plugin); |
| 382 | called_plugin->claim_file_handler = handler; |
| 383 | return LDPS_OK; |
| 384 | } |
| 385 | |
| 386 | /* Register an all-symbols-read handler. */ |
| 387 | static enum ld_plugin_status |
| 388 | register_all_symbols_read (ld_plugin_all_symbols_read_handler handler) |
| 389 | { |
| 390 | ASSERT (called_plugin); |
| 391 | called_plugin->all_symbols_read_handler = handler; |
| 392 | return LDPS_OK; |
| 393 | } |
| 394 | |
| 395 | /* Register a cleanup handler. */ |
| 396 | static enum ld_plugin_status |
| 397 | register_cleanup (ld_plugin_cleanup_handler handler) |
| 398 | { |
| 399 | ASSERT (called_plugin); |
| 400 | called_plugin->cleanup_handler = handler; |
| 401 | return LDPS_OK; |
| 402 | } |
| 403 | |
| 404 | /* Add symbols from a plugin-claimed input file. */ |
| 405 | static enum ld_plugin_status |
| 406 | add_symbols (void *handle, int nsyms, const struct ld_plugin_symbol *syms) |
| 407 | { |
| 408 | asymbol **symptrs; |
| 409 | bfd *abfd = handle; |
| 410 | int n; |
| 411 | |
| 412 | ASSERT (called_plugin); |
| 413 | symptrs = xmalloc (nsyms * sizeof *symptrs); |
| 414 | for (n = 0; n < nsyms; n++) |
| 415 | { |
| 416 | enum ld_plugin_status rv; |
| 417 | asymbol *bfdsym; |
| 418 | |
| 419 | bfdsym = bfd_make_empty_symbol (abfd); |
| 420 | symptrs[n] = bfdsym; |
| 421 | rv = asymbol_from_plugin_symbol (abfd, bfdsym, syms + n); |
| 422 | if (rv != LDPS_OK) |
| 423 | return rv; |
| 424 | } |
| 425 | bfd_set_symtab (abfd, symptrs, nsyms); |
| 426 | return LDPS_OK; |
| 427 | } |
| 428 | |
| 429 | /* Get the input file information with an open (possibly re-opened) |
| 430 | file descriptor. */ |
| 431 | static enum ld_plugin_status |
| 432 | get_input_file (const void *handle ATTRIBUTE_UNUSED, |
| 433 | struct ld_plugin_input_file *file ATTRIBUTE_UNUSED) |
| 434 | { |
| 435 | ASSERT (called_plugin); |
| 436 | return LDPS_ERR; |
| 437 | } |
| 438 | |
| 439 | /* Release the input file. */ |
| 440 | static enum ld_plugin_status |
| 441 | release_input_file (const void *handle ATTRIBUTE_UNUSED) |
| 442 | { |
| 443 | ASSERT (called_plugin); |
| 444 | return LDPS_ERR; |
| 445 | } |
| 446 | |
| 447 | /* Return TRUE if a defined symbol might be reachable from outside the |
| 448 | universe of claimed objects. */ |
| 449 | static inline bfd_boolean |
| 450 | is_visible_from_outside (struct ld_plugin_symbol *lsym, |
| 451 | struct bfd_link_hash_entry *blhe) |
| 452 | { |
| 453 | struct bfd_sym_chain *sym; |
| 454 | |
| 455 | if (link_info.relocatable) |
| 456 | return TRUE; |
| 457 | if (link_info.export_dynamic || !link_info.executable) |
| 458 | { |
| 459 | /* Check if symbol is hidden by version script. */ |
| 460 | if (bfd_hide_sym_by_version (link_info.version_info, |
| 461 | blhe->root.string)) |
| 462 | return FALSE; |
| 463 | /* Only ELF symbols really have visibility. */ |
| 464 | if (bfd_get_flavour (link_info.output_bfd) == bfd_target_elf_flavour) |
| 465 | { |
| 466 | struct elf_link_hash_entry *el = (struct elf_link_hash_entry *)blhe; |
| 467 | int vis = ELF_ST_VISIBILITY (el->other); |
| 468 | return vis == STV_DEFAULT || vis == STV_PROTECTED; |
| 469 | } |
| 470 | /* On non-ELF targets, we can safely make inferences by considering |
| 471 | what visibility the plugin would have liked to apply when it first |
| 472 | sent us the symbol. During ELF symbol processing, visibility only |
| 473 | ever becomes more restrictive, not less, when symbols are merged, |
| 474 | so this is a conservative estimate; it may give false positives, |
| 475 | declaring something visible from outside when it in fact would |
| 476 | not have been, but this will only lead to missed optimisation |
| 477 | opportunities during LTRANS at worst; it will not give false |
| 478 | negatives, which can lead to the disastrous conclusion that the |
| 479 | related symbol is IRONLY. (See GCC PR46319 for an example.) */ |
| 480 | return (lsym->visibility == LDPV_DEFAULT |
| 481 | || lsym->visibility == LDPV_PROTECTED); |
| 482 | } |
| 483 | |
| 484 | for (sym = &entry_symbol; sym != NULL; sym = sym->next) |
| 485 | if (sym->name |
| 486 | && strcmp (sym->name, blhe->root.string) == 0) |
| 487 | return TRUE; |
| 488 | |
| 489 | return FALSE; |
| 490 | } |
| 491 | |
| 492 | /* Get the symbol resolution info for a plugin-claimed input file. */ |
| 493 | static enum ld_plugin_status |
| 494 | get_symbols (const void *handle, int nsyms, struct ld_plugin_symbol *syms, |
| 495 | int def_ironly_exp) |
| 496 | { |
| 497 | const bfd *abfd = handle; |
| 498 | int n; |
| 499 | |
| 500 | ASSERT (called_plugin); |
| 501 | for (n = 0; n < nsyms; n++) |
| 502 | { |
| 503 | struct bfd_link_hash_entry *blhe; |
| 504 | asection *owner_sec; |
| 505 | int res; |
| 506 | |
| 507 | if (syms[n].def != LDPK_UNDEF) |
| 508 | blhe = bfd_link_hash_lookup (link_info.hash, syms[n].name, |
| 509 | FALSE, FALSE, TRUE); |
| 510 | else |
| 511 | blhe = bfd_wrapped_link_hash_lookup (link_info.output_bfd, &link_info, |
| 512 | syms[n].name, FALSE, FALSE, TRUE); |
| 513 | if (!blhe) |
| 514 | { |
| 515 | res = LDPR_UNKNOWN; |
| 516 | goto report_symbol; |
| 517 | } |
| 518 | |
| 519 | /* Determine resolution from blhe type and symbol's original type. */ |
| 520 | if (blhe->type == bfd_link_hash_undefined |
| 521 | || blhe->type == bfd_link_hash_undefweak) |
| 522 | { |
| 523 | res = LDPR_UNDEF; |
| 524 | goto report_symbol; |
| 525 | } |
| 526 | if (blhe->type != bfd_link_hash_defined |
| 527 | && blhe->type != bfd_link_hash_defweak |
| 528 | && blhe->type != bfd_link_hash_common) |
| 529 | { |
| 530 | /* We should not have a new, indirect or warning symbol here. */ |
| 531 | einfo ("%P%F: %s: plugin symbol table corrupt (sym type %d)\n", |
| 532 | called_plugin->name, blhe->type); |
| 533 | } |
| 534 | |
| 535 | /* Find out which section owns the symbol. Since it's not undef, |
| 536 | it must have an owner; if it's not a common symbol, both defs |
| 537 | and weakdefs keep it in the same place. */ |
| 538 | owner_sec = (blhe->type == bfd_link_hash_common |
| 539 | ? blhe->u.c.p->section |
| 540 | : blhe->u.def.section); |
| 541 | |
| 542 | |
| 543 | /* If it was originally undefined or common, then it has been |
| 544 | resolved; determine how. */ |
| 545 | if (syms[n].def == LDPK_UNDEF |
| 546 | || syms[n].def == LDPK_WEAKUNDEF |
| 547 | || syms[n].def == LDPK_COMMON) |
| 548 | { |
| 549 | if (owner_sec->owner == link_info.output_bfd) |
| 550 | res = LDPR_RESOLVED_EXEC; |
| 551 | else if (owner_sec->owner == abfd) |
| 552 | res = LDPR_PREVAILING_DEF_IRONLY; |
| 553 | else if (is_ir_dummy_bfd (owner_sec->owner)) |
| 554 | res = LDPR_RESOLVED_IR; |
| 555 | else if (owner_sec->owner != NULL |
| 556 | && (owner_sec->owner->flags & DYNAMIC) != 0) |
| 557 | res = LDPR_RESOLVED_DYN; |
| 558 | else |
| 559 | res = LDPR_RESOLVED_EXEC; |
| 560 | } |
| 561 | |
| 562 | /* Was originally def, or weakdef. Does it prevail? If the |
| 563 | owner is the original dummy bfd that supplied it, then this |
| 564 | is the definition that has prevailed. */ |
| 565 | else if (owner_sec->owner == link_info.output_bfd) |
| 566 | res = LDPR_PREEMPTED_REG; |
| 567 | else if (owner_sec->owner == abfd) |
| 568 | res = LDPR_PREVAILING_DEF_IRONLY; |
| 569 | |
| 570 | /* Was originally def, weakdef, or common, but has been pre-empted. */ |
| 571 | else if (is_ir_dummy_bfd (owner_sec->owner)) |
| 572 | res = LDPR_PREEMPTED_IR; |
| 573 | else |
| 574 | res = LDPR_PREEMPTED_REG; |
| 575 | |
| 576 | if (res == LDPR_PREVAILING_DEF_IRONLY) |
| 577 | { |
| 578 | /* We need to know if the sym is referenced from non-IR files. Or |
| 579 | even potentially-referenced, perhaps in a future final link if |
| 580 | this is a partial one, perhaps dynamically at load-time if the |
| 581 | symbol is externally visible. */ |
| 582 | if (blhe->non_ir_ref) |
| 583 | res = LDPR_PREVAILING_DEF; |
| 584 | else if (is_visible_from_outside (&syms[n], blhe)) |
| 585 | res = def_ironly_exp; |
| 586 | } |
| 587 | |
| 588 | report_symbol: |
| 589 | syms[n].resolution = res; |
| 590 | if (report_plugin_symbols) |
| 591 | einfo (_("%P: %B: symbol `%s' " |
| 592 | "definition: %d, visibility: %d, resolution: %d\n"), |
| 593 | abfd, syms[n].name, |
| 594 | syms[n].def, syms[n].visibility, res); |
| 595 | } |
| 596 | return LDPS_OK; |
| 597 | } |
| 598 | |
| 599 | static enum ld_plugin_status |
| 600 | get_symbols_v1 (const void *handle, int nsyms, struct ld_plugin_symbol *syms) |
| 601 | { |
| 602 | return get_symbols (handle, nsyms, syms, LDPR_PREVAILING_DEF); |
| 603 | } |
| 604 | |
| 605 | static enum ld_plugin_status |
| 606 | get_symbols_v2 (const void *handle, int nsyms, struct ld_plugin_symbol *syms) |
| 607 | { |
| 608 | return get_symbols (handle, nsyms, syms, LDPR_PREVAILING_DEF_IRONLY_EXP); |
| 609 | } |
| 610 | |
| 611 | /* Add a new (real) input file generated by a plugin. */ |
| 612 | static enum ld_plugin_status |
| 613 | add_input_file (const char *pathname) |
| 614 | { |
| 615 | ASSERT (called_plugin); |
| 616 | if (!lang_add_input_file (xstrdup (pathname), lang_input_file_is_file_enum, |
| 617 | NULL)) |
| 618 | return LDPS_ERR; |
| 619 | return LDPS_OK; |
| 620 | } |
| 621 | |
| 622 | /* Add a new (real) library required by a plugin. */ |
| 623 | static enum ld_plugin_status |
| 624 | add_input_library (const char *pathname) |
| 625 | { |
| 626 | ASSERT (called_plugin); |
| 627 | if (!lang_add_input_file (xstrdup (pathname), lang_input_file_is_l_enum, |
| 628 | NULL)) |
| 629 | return LDPS_ERR; |
| 630 | return LDPS_OK; |
| 631 | } |
| 632 | |
| 633 | /* Set the extra library path to be used by libraries added via |
| 634 | add_input_library. */ |
| 635 | static enum ld_plugin_status |
| 636 | set_extra_library_path (const char *path) |
| 637 | { |
| 638 | ASSERT (called_plugin); |
| 639 | ldfile_add_library_path (xstrdup (path), FALSE); |
| 640 | return LDPS_OK; |
| 641 | } |
| 642 | |
| 643 | /* Issue a diagnostic message from a plugin. */ |
| 644 | static enum ld_plugin_status |
| 645 | message (int level, const char *format, ...) |
| 646 | { |
| 647 | va_list args; |
| 648 | va_start (args, format); |
| 649 | |
| 650 | switch (level) |
| 651 | { |
| 652 | case LDPL_INFO: |
| 653 | vfinfo (stdout, format, args, FALSE); |
| 654 | putchar ('\n'); |
| 655 | break; |
| 656 | case LDPL_WARNING: |
| 657 | vfinfo (stdout, format, args, TRUE); |
| 658 | putchar ('\n'); |
| 659 | break; |
| 660 | case LDPL_FATAL: |
| 661 | case LDPL_ERROR: |
| 662 | default: |
| 663 | { |
| 664 | char *newfmt = ACONCAT ((level == LDPL_FATAL ? "%P%F: " : "%P%X: ", |
| 665 | format, "\n", (const char *) NULL)); |
| 666 | fflush (stdout); |
| 667 | vfinfo (stderr, newfmt, args, TRUE); |
| 668 | fflush (stderr); |
| 669 | } |
| 670 | break; |
| 671 | } |
| 672 | |
| 673 | va_end (args); |
| 674 | return LDPS_OK; |
| 675 | } |
| 676 | |
| 677 | /* Helper to size leading part of tv array and set it up. */ |
| 678 | static void |
| 679 | set_tv_header (struct ld_plugin_tv *tv) |
| 680 | { |
| 681 | size_t i; |
| 682 | |
| 683 | /* Version info. */ |
| 684 | static const unsigned int major = (unsigned)(BFD_VERSION / 100000000UL); |
| 685 | static const unsigned int minor = (unsigned)(BFD_VERSION / 1000000UL) % 100; |
| 686 | |
| 687 | for (i = 0; i < tv_header_size; i++) |
| 688 | { |
| 689 | tv[i].tv_tag = tv_header_tags[i]; |
| 690 | #define TVU(x) tv[i].tv_u.tv_ ## x |
| 691 | switch (tv[i].tv_tag) |
| 692 | { |
| 693 | case LDPT_MESSAGE: |
| 694 | TVU(message) = message; |
| 695 | break; |
| 696 | case LDPT_API_VERSION: |
| 697 | TVU(val) = LD_PLUGIN_API_VERSION; |
| 698 | break; |
| 699 | case LDPT_GNU_LD_VERSION: |
| 700 | TVU(val) = major * 100 + minor; |
| 701 | break; |
| 702 | case LDPT_LINKER_OUTPUT: |
| 703 | TVU(val) = (link_info.relocatable |
| 704 | ? LDPO_REL |
| 705 | : (link_info.executable |
| 706 | ? (link_info.pie ? LDPO_PIE : LDPO_EXEC) |
| 707 | : LDPO_DYN)); |
| 708 | break; |
| 709 | case LDPT_OUTPUT_NAME: |
| 710 | TVU(string) = output_filename; |
| 711 | break; |
| 712 | case LDPT_REGISTER_CLAIM_FILE_HOOK: |
| 713 | TVU(register_claim_file) = register_claim_file; |
| 714 | break; |
| 715 | case LDPT_REGISTER_ALL_SYMBOLS_READ_HOOK: |
| 716 | TVU(register_all_symbols_read) = register_all_symbols_read; |
| 717 | break; |
| 718 | case LDPT_REGISTER_CLEANUP_HOOK: |
| 719 | TVU(register_cleanup) = register_cleanup; |
| 720 | break; |
| 721 | case LDPT_ADD_SYMBOLS: |
| 722 | TVU(add_symbols) = add_symbols; |
| 723 | break; |
| 724 | case LDPT_GET_INPUT_FILE: |
| 725 | TVU(get_input_file) = get_input_file; |
| 726 | break; |
| 727 | case LDPT_RELEASE_INPUT_FILE: |
| 728 | TVU(release_input_file) = release_input_file; |
| 729 | break; |
| 730 | case LDPT_GET_SYMBOLS: |
| 731 | TVU(get_symbols) = get_symbols_v1; |
| 732 | break; |
| 733 | case LDPT_GET_SYMBOLS_V2: |
| 734 | TVU(get_symbols) = get_symbols_v2; |
| 735 | break; |
| 736 | case LDPT_ADD_INPUT_FILE: |
| 737 | TVU(add_input_file) = add_input_file; |
| 738 | break; |
| 739 | case LDPT_ADD_INPUT_LIBRARY: |
| 740 | TVU(add_input_library) = add_input_library; |
| 741 | break; |
| 742 | case LDPT_SET_EXTRA_LIBRARY_PATH: |
| 743 | TVU(set_extra_library_path) = set_extra_library_path; |
| 744 | break; |
| 745 | default: |
| 746 | /* Added a new entry to the array without adding |
| 747 | a new case to set up its value is a bug. */ |
| 748 | FAIL (); |
| 749 | } |
| 750 | #undef TVU |
| 751 | } |
| 752 | } |
| 753 | |
| 754 | /* Append the per-plugin args list and trailing LDPT_NULL to tv. */ |
| 755 | static void |
| 756 | set_tv_plugin_args (plugin_t *plugin, struct ld_plugin_tv *tv) |
| 757 | { |
| 758 | plugin_arg_t *arg = plugin->args; |
| 759 | while (arg) |
| 760 | { |
| 761 | tv->tv_tag = LDPT_OPTION; |
| 762 | tv->tv_u.tv_string = arg->arg; |
| 763 | arg = arg->next; |
| 764 | tv++; |
| 765 | } |
| 766 | tv->tv_tag = LDPT_NULL; |
| 767 | tv->tv_u.tv_val = 0; |
| 768 | } |
| 769 | |
| 770 | /* Return true if any plugins are active this run. Only valid |
| 771 | after options have been processed. */ |
| 772 | bfd_boolean |
| 773 | plugin_active_plugins_p (void) |
| 774 | { |
| 775 | return plugins_list != NULL; |
| 776 | } |
| 777 | |
| 778 | /* Load up and initialise all plugins after argument parsing. */ |
| 779 | void |
| 780 | plugin_load_plugins (void) |
| 781 | { |
| 782 | struct ld_plugin_tv *my_tv; |
| 783 | unsigned int max_args = 0; |
| 784 | plugin_t *curplug = plugins_list; |
| 785 | |
| 786 | /* If there are no plugins, we need do nothing this run. */ |
| 787 | if (!curplug) |
| 788 | return; |
| 789 | |
| 790 | /* First pass over plugins to find max # args needed so that we |
| 791 | can size and allocate the tv array. */ |
| 792 | while (curplug) |
| 793 | { |
| 794 | if (curplug->n_args > max_args) |
| 795 | max_args = curplug->n_args; |
| 796 | curplug = curplug->next; |
| 797 | } |
| 798 | |
| 799 | /* Allocate tv array and initialise constant part. */ |
| 800 | my_tv = xmalloc ((max_args + 1 + tv_header_size) * sizeof *my_tv); |
| 801 | set_tv_header (my_tv); |
| 802 | |
| 803 | /* Pass over plugins again, activating them. */ |
| 804 | curplug = plugins_list; |
| 805 | while (curplug) |
| 806 | { |
| 807 | enum ld_plugin_status rv; |
| 808 | ld_plugin_onload onloadfn; |
| 809 | |
| 810 | onloadfn = (ld_plugin_onload) dlsym (curplug->dlhandle, "onload"); |
| 811 | if (!onloadfn) |
| 812 | onloadfn = (ld_plugin_onload) dlsym (curplug->dlhandle, "_onload"); |
| 813 | if (!onloadfn) |
| 814 | einfo (_("%P%F: %s: error loading plugin: %s\n"), |
| 815 | curplug->name, dlerror ()); |
| 816 | set_tv_plugin_args (curplug, &my_tv[tv_header_size]); |
| 817 | called_plugin = curplug; |
| 818 | rv = (*onloadfn) (my_tv); |
| 819 | called_plugin = NULL; |
| 820 | if (rv != LDPS_OK) |
| 821 | einfo (_("%P%F: %s: plugin error: %d\n"), curplug->name, rv); |
| 822 | curplug = curplug->next; |
| 823 | } |
| 824 | |
| 825 | /* Since plugin(s) inited ok, assume they're going to want symbol |
| 826 | resolutions, which needs us to track which symbols are referenced |
| 827 | by non-IR files using the linker's notice callback. */ |
| 828 | orig_notice_all = link_info.notice_all; |
| 829 | orig_callbacks = link_info.callbacks; |
| 830 | plugin_callbacks = *orig_callbacks; |
| 831 | plugin_callbacks.notice = &plugin_notice; |
| 832 | link_info.notice_all = TRUE; |
| 833 | link_info.callbacks = &plugin_callbacks; |
| 834 | } |
| 835 | |
| 836 | /* Call 'claim file' hook for all plugins. */ |
| 837 | static int |
| 838 | plugin_call_claim_file (const struct ld_plugin_input_file *file, int *claimed) |
| 839 | { |
| 840 | plugin_t *curplug = plugins_list; |
| 841 | *claimed = FALSE; |
| 842 | if (no_more_claiming) |
| 843 | return 0; |
| 844 | while (curplug && !*claimed) |
| 845 | { |
| 846 | if (curplug->claim_file_handler) |
| 847 | { |
| 848 | enum ld_plugin_status rv; |
| 849 | called_plugin = curplug; |
| 850 | rv = (*curplug->claim_file_handler) (file, claimed); |
| 851 | called_plugin = NULL; |
| 852 | if (rv != LDPS_OK) |
| 853 | set_plugin_error (curplug->name); |
| 854 | } |
| 855 | curplug = curplug->next; |
| 856 | } |
| 857 | return plugin_error_p () ? -1 : 0; |
| 858 | } |
| 859 | |
| 860 | void |
| 861 | plugin_maybe_claim (struct ld_plugin_input_file *file, |
| 862 | lang_input_statement_type *entry) |
| 863 | { |
| 864 | int claimed = 0; |
| 865 | |
| 866 | /* We create a dummy BFD, initially empty, to house whatever symbols |
| 867 | the plugin may want to add. */ |
| 868 | file->handle = plugin_get_ir_dummy_bfd (entry->the_bfd->filename, |
| 869 | entry->the_bfd); |
| 870 | if (plugin_call_claim_file (file, &claimed)) |
| 871 | einfo (_("%P%F: %s: plugin reported error claiming file\n"), |
| 872 | plugin_error_plugin ()); |
| 873 | /* fd belongs to us, not the plugin; but we don't need it. */ |
| 874 | close (file->fd); |
| 875 | if (claimed) |
| 876 | { |
| 877 | /* Discard the real file's BFD and substitute the dummy one. */ |
| 878 | |
| 879 | /* BFD archive handling caches elements so we can't call |
| 880 | bfd_close for archives. */ |
| 881 | if (entry->the_bfd->my_archive == NULL) |
| 882 | bfd_close (entry->the_bfd); |
| 883 | entry->the_bfd = file->handle; |
| 884 | entry->flags.claimed = TRUE; |
| 885 | bfd_make_readable (entry->the_bfd); |
| 886 | } |
| 887 | else |
| 888 | { |
| 889 | /* If plugin didn't claim the file, we don't need the dummy bfd. |
| 890 | Can't avoid speculatively creating it, alas. */ |
| 891 | bfd_close_all_done (file->handle); |
| 892 | entry->flags.claimed = FALSE; |
| 893 | } |
| 894 | } |
| 895 | |
| 896 | /* Call 'all symbols read' hook for all plugins. */ |
| 897 | int |
| 898 | plugin_call_all_symbols_read (void) |
| 899 | { |
| 900 | plugin_t *curplug = plugins_list; |
| 901 | |
| 902 | /* Disable any further file-claiming. */ |
| 903 | no_more_claiming = TRUE; |
| 904 | |
| 905 | while (curplug) |
| 906 | { |
| 907 | if (curplug->all_symbols_read_handler) |
| 908 | { |
| 909 | enum ld_plugin_status rv; |
| 910 | called_plugin = curplug; |
| 911 | rv = (*curplug->all_symbols_read_handler) (); |
| 912 | called_plugin = NULL; |
| 913 | if (rv != LDPS_OK) |
| 914 | set_plugin_error (curplug->name); |
| 915 | } |
| 916 | curplug = curplug->next; |
| 917 | } |
| 918 | return plugin_error_p () ? -1 : 0; |
| 919 | } |
| 920 | |
| 921 | /* Call 'cleanup' hook for all plugins at exit. */ |
| 922 | void |
| 923 | plugin_call_cleanup (void) |
| 924 | { |
| 925 | plugin_t *curplug = plugins_list; |
| 926 | while (curplug) |
| 927 | { |
| 928 | if (curplug->cleanup_handler && !curplug->cleanup_done) |
| 929 | { |
| 930 | enum ld_plugin_status rv; |
| 931 | curplug->cleanup_done = TRUE; |
| 932 | called_plugin = curplug; |
| 933 | rv = (*curplug->cleanup_handler) (); |
| 934 | called_plugin = NULL; |
| 935 | if (rv != LDPS_OK) |
| 936 | info_msg (_("%P: %s: error in plugin cleanup: %d (ignored)\n"), |
| 937 | curplug->name, rv); |
| 938 | dlclose (curplug->dlhandle); |
| 939 | } |
| 940 | curplug = curplug->next; |
| 941 | } |
| 942 | } |
| 943 | |
| 944 | /* To determine which symbols should be resolved LDPR_PREVAILING_DEF |
| 945 | and which LDPR_PREVAILING_DEF_IRONLY, we notice all the symbols as |
| 946 | the linker adds them to the linker hash table. Mark those |
| 947 | referenced from a non-IR file with non_ir_ref. We have to |
| 948 | notice_all symbols, because we won't necessarily know until later |
| 949 | which ones will be contributed by IR files. */ |
| 950 | static bfd_boolean |
| 951 | plugin_notice (struct bfd_link_info *info, |
| 952 | struct bfd_link_hash_entry *h, |
| 953 | bfd *abfd, |
| 954 | asection *section, |
| 955 | bfd_vma value, |
| 956 | flagword flags, |
| 957 | const char *string) |
| 958 | { |
| 959 | if (h != NULL) |
| 960 | { |
| 961 | bfd *sym_bfd; |
| 962 | |
| 963 | /* Nothing to do here if this def/ref is from an IR dummy BFD. */ |
| 964 | if (is_ir_dummy_bfd (abfd)) |
| 965 | ; |
| 966 | |
| 967 | /* Making an indirect symbol counts as a reference unless this |
| 968 | is a brand new symbol. */ |
| 969 | else if (bfd_is_ind_section (section) |
| 970 | || (flags & BSF_INDIRECT) != 0) |
| 971 | { |
| 972 | if (h->type != bfd_link_hash_new) |
| 973 | { |
| 974 | struct bfd_link_hash_entry *inh; |
| 975 | |
| 976 | h->non_ir_ref = TRUE; |
| 977 | inh = bfd_wrapped_link_hash_lookup (abfd, info, string, FALSE, |
| 978 | FALSE, FALSE); |
| 979 | if (inh != NULL) |
| 980 | inh->non_ir_ref = TRUE; |
| 981 | } |
| 982 | } |
| 983 | |
| 984 | /* Nothing to do here for warning symbols. */ |
| 985 | else if ((flags & BSF_WARNING) != 0) |
| 986 | ; |
| 987 | |
| 988 | /* Nothing to do here for constructor symbols. */ |
| 989 | else if ((flags & BSF_CONSTRUCTOR) != 0) |
| 990 | ; |
| 991 | |
| 992 | /* If this is a ref, set non_ir_ref. */ |
| 993 | else if (bfd_is_und_section (section)) |
| 994 | { |
| 995 | /* Replace the undefined dummy bfd with the real one. */ |
| 996 | if ((h->type == bfd_link_hash_undefined |
| 997 | || h->type == bfd_link_hash_undefweak) |
| 998 | && (h->u.undef.abfd == NULL |
| 999 | || (h->u.undef.abfd->flags & BFD_PLUGIN) != 0)) |
| 1000 | h->u.undef.abfd = abfd; |
| 1001 | h->non_ir_ref = TRUE; |
| 1002 | } |
| 1003 | |
| 1004 | /* Otherwise, it must be a new def. Ensure any symbol defined |
| 1005 | in an IR dummy BFD takes on a new value from a real BFD. |
| 1006 | Weak symbols are not normally overridden by a new weak |
| 1007 | definition, and strong symbols will normally cause multiple |
| 1008 | definition errors. Avoid this by making the symbol appear |
| 1009 | to be undefined. */ |
| 1010 | else if (((h->type == bfd_link_hash_defweak |
| 1011 | || h->type == bfd_link_hash_defined) |
| 1012 | && is_ir_dummy_bfd (sym_bfd = h->u.def.section->owner)) |
| 1013 | || (h->type == bfd_link_hash_common |
| 1014 | && is_ir_dummy_bfd (sym_bfd = h->u.c.p->section->owner))) |
| 1015 | { |
| 1016 | h->type = bfd_link_hash_undefweak; |
| 1017 | h->u.undef.abfd = sym_bfd; |
| 1018 | } |
| 1019 | } |
| 1020 | |
| 1021 | /* Continue with cref/nocrossref/trace-sym processing. */ |
| 1022 | if (h == NULL |
| 1023 | || orig_notice_all |
| 1024 | || (info->notice_hash != NULL |
| 1025 | && bfd_hash_lookup (info->notice_hash, h->root.string, |
| 1026 | FALSE, FALSE) != NULL)) |
| 1027 | return (*orig_callbacks->notice) (info, h, |
| 1028 | abfd, section, value, flags, string); |
| 1029 | return TRUE; |
| 1030 | } |
| 1031 | |
| 1032 | /* Return true if ABFD, a dynamic library, should be reloaded. */ |
| 1033 | |
| 1034 | bfd_boolean |
| 1035 | plugin_should_reload (bfd *abfd) |
| 1036 | { |
| 1037 | return (bfd_get_flavour (abfd) == bfd_target_elf_flavour |
| 1038 | && (elf_dyn_lib_class (abfd) & DYN_AS_NEEDED) != 0); |
| 1039 | } |