bfd/plugin.c

   1 /* Plugin support for BFD.
   2    Copyright (C) 2009-2016 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_copy_link_hash_symbol_type     _bfd_generic_copy_link_hash_symbol_type
 109 #define bfd_plugin_bfd_link_check_relocs              _bfd_generic_link_check_relocs
 110
 111 static enum ld_plugin_status
 112 message (int level ATTRIBUTE_UNUSED,
 113          const char * format, ...)
 114 {
 115   va_list args;
 116   va_start (args, format);
 117   printf ("bfd plugin: ");
 118   vprintf (format, args);
 119   putchar ('\n');
 120   va_end (args);
 121   return LDPS_OK;
 122 }
 123
 124 /* Register a claim-file handler. */
 125 static ld_plugin_claim_file_handler claim_file;
 126
 127 static enum ld_plugin_status
 128 register_claim_file (ld_plugin_claim_file_handler handler)
 129 {
 130   claim_file = handler;
 131   return LDPS_OK;
 132 }
 133
 134 static enum ld_plugin_status
 135 add_symbols (void * handle,
 136              int nsyms,
 137              const struct ld_plugin_symbol * syms)
 138 {
 139   bfd *abfd = handle;
 140   struct plugin_data_struct *plugin_data =
 141     bfd_alloc (abfd, sizeof (plugin_data_struct));
 142
 143   plugin_data->nsyms = nsyms;
 144   plugin_data->syms = syms;
 145
 146   if (nsyms != 0)
 147     abfd->flags |= HAS_SYMS;
 148
 149   abfd->tdata.plugin_data = plugin_data;
 150   return LDPS_OK;
 151 }
 152
 153 static const char *plugin_program_name;
 154
 155 void
 156 bfd_plugin_set_program_name (const char *program_name)
 157 {
 158   plugin_program_name = program_name;
 159 }
 160
 161 static int
 162 try_claim (bfd *abfd)
 163 {
 164   int claimed = 0;
 165   struct ld_plugin_input_file file;
 166   bfd *iobfd;
 167
 168   file.name = abfd->filename;
 169
 170   if (abfd->my_archive && !bfd_is_thin_archive (abfd->my_archive))
 171     {
 172       iobfd = abfd->my_archive;
 173       file.offset = abfd->origin;
 174       file.filesize = arelt_size (abfd);
 175     }
 176   else
 177     {
 178       iobfd = abfd;
 179       file.offset = 0;
 180       file.filesize = 0;
 181     }
 182
 183   if (!iobfd->iostream && !bfd_open_file (iobfd))
 184     return 0;
 185
 186   file.fd = fileno ((FILE *) iobfd->iostream);
 187
 188   if (!abfd->my_archive || bfd_is_thin_archive (abfd->my_archive))
 189     {
 190       struct stat stat_buf;
 191       if (fstat (file.fd, &stat_buf))
 192         return 0;
 193       file.filesize = stat_buf.st_size;
 194     }
 195
 196   file.handle = abfd;
 197   off_t cur_offset = lseek(file.fd, 0, SEEK_CUR);
 198   claim_file (&file, &claimed);
 199   lseek(file.fd, cur_offset, SEEK_SET);
 200   if (!claimed)
 201     return 0;
 202
 203   return 1;
 204 }
 205
 206 static int
 207 try_load_plugin (const char *pname, bfd *abfd, int *has_plugin_p)
 208 {
 209   void *plugin_handle;
 210   struct ld_plugin_tv tv[4];
 211   int i;
 212   ld_plugin_onload onload;
 213   enum ld_plugin_status status;
 214
 215   *has_plugin_p = 0;
 216
 217   plugin_handle = dlopen (pname, RTLD_NOW);
 218   if (!plugin_handle)
 219     {
 220       (*_bfd_error_handler)("%s\n", dlerror ());
 221       return 0;
 222     }
 223
 224   onload = dlsym (plugin_handle, "onload");
 225   if (!onload)
 226     goto err;
 227
 228   i = 0;
 229   tv[i].tv_tag = LDPT_MESSAGE;
 230   tv[i].tv_u.tv_message = message;
 231
 232   ++i;
 233   tv[i].tv_tag = LDPT_REGISTER_CLAIM_FILE_HOOK;
 234   tv[i].tv_u.tv_register_claim_file = register_claim_file;
 235
 236   ++i;
 237   tv[i].tv_tag = LDPT_ADD_SYMBOLS;
 238   tv[i].tv_u.tv_add_symbols = add_symbols;
 239
 240   ++i;
 241   tv[i].tv_tag = LDPT_NULL;
 242   tv[i].tv_u.tv_val = 0;
 243
 244   status = (*onload)(tv);
 245
 246   if (status != LDPS_OK)
 247     goto err;
 248
 249   *has_plugin_p = 1;
 250
 251   abfd->plugin_format = bfd_plugin_no;
 252
 253   if (!claim_file)
 254     goto err;
 255
 256   if (!try_claim (abfd))
 257     goto err;
 258
 259   abfd->plugin_format = bfd_plugin_yes;
 260
 261   return 1;
 262
 263  err:
 264   return 0;
 265 }
 266
 267 /* There may be plugin libraries in lib/bfd-plugins.  */
 268
 269 static int has_plugin = -1;
 270
 271 static const bfd_target *(*ld_plugin_object_p) (bfd *);
 272
 273 static const char *plugin_name;
 274
 275 void
 276 bfd_plugin_set_plugin (const char *p)
 277 {
 278   plugin_name = p;
 279   has_plugin = p != NULL;
 280 }
 281
 282 /* Return TRUE if a plugin library is used.  */
 283
 284 bfd_boolean
 285 bfd_plugin_specified_p (void)
 286 {
 287   return has_plugin > 0;
 288 }
 289
 290 /* Return TRUE if ABFD can be claimed by linker LTO plugin.  */
 291
 292 bfd_boolean
 293 bfd_link_plugin_object_p (bfd *abfd)
 294 {
 295   if (ld_plugin_object_p)
 296     return ld_plugin_object_p (abfd) != NULL;
 297   return FALSE;
 298 }
 299
 300 extern const bfd_target plugin_vec;
 301
 302 /* Return TRUE if TARGET is a pointer to plugin_vec.  */
 303
 304 bfd_boolean
 305 bfd_plugin_target_p (const bfd_target *target)
 306 {
 307   return target == &plugin_vec;
 308 }
 309
 310 /* Register OBJECT_P to be used by bfd_plugin_object_p.  */
 311
 312 void
 313 register_ld_plugin_object_p (const bfd_target *(*object_p) (bfd *))
 314 {
 315   ld_plugin_object_p = object_p;
 316 }
 317
 318 static int
 319 load_plugin (bfd *abfd)
 320 {
 321   char *plugin_dir;
 322   char *p;
 323   DIR *d;
 324   struct dirent *ent;
 325   int found = 0;
 326
 327   if (!has_plugin)
 328     return found;
 329
 330   if (plugin_name)
 331     return try_load_plugin (plugin_name, abfd, &has_plugin);
 332
 333   if (plugin_program_name == NULL)
 334     return found;
 335
 336   plugin_dir = concat (BINDIR, "/../lib/bfd-plugins", NULL);
 337   p = make_relative_prefix (plugin_program_name,
 338                             BINDIR,
 339                             plugin_dir);
 340   free (plugin_dir);
 341   plugin_dir = NULL;
 342
 343   d = opendir (p);
 344   if (!d)
 345     goto out;
 346
 347   while ((ent = readdir (d)))
 348     {
 349       char *full_name;
 350       struct stat s;
 351       int valid_plugin;
 352
 353       full_name = concat (p, "/", ent->d_name, NULL);
 354       if (stat(full_name, &s) == 0 && S_ISREG (s.st_mode))
 355         found = try_load_plugin (full_name, abfd, &valid_plugin);
 356       if (has_plugin <= 0)
 357         has_plugin = valid_plugin;
 358       free (full_name);
 359       if (found)
 360         break;
 361     }
 362
 363  out:
 364   free (p);
 365   if (d)
 366     closedir (d);
 367
 368   return found;
 369 }
 370
 371
 372 static const bfd_target *
 373 bfd_plugin_object_p (bfd *abfd)
 374 {
 375   if (ld_plugin_object_p)
 376     return ld_plugin_object_p (abfd);
 377
 378   if (abfd->plugin_format == bfd_plugin_unknown && !load_plugin (abfd))
 379     return NULL;
 380
 381   return abfd->plugin_format == bfd_plugin_yes ? abfd->xvec : NULL;
 382 }
 383
 384 /* Copy any private info we understand from the input bfd
 385    to the output bfd.  */
 386
 387 static bfd_boolean
 388 bfd_plugin_bfd_copy_private_bfd_data (bfd *ibfd ATTRIBUTE_UNUSED,
 389                                       bfd *obfd ATTRIBUTE_UNUSED)
 390 {
 391   BFD_ASSERT (0);
 392   return TRUE;
 393 }
 394
 395 /* Copy any private info we understand from the input section
 396    to the output section.  */
 397
 398 static bfd_boolean
 399 bfd_plugin_bfd_copy_private_section_data (bfd *ibfd ATTRIBUTE_UNUSED,
 400                                           asection *isection ATTRIBUTE_UNUSED,
 401                                           bfd *obfd ATTRIBUTE_UNUSED,
 402                                           asection *osection ATTRIBUTE_UNUSED)
 403 {
 404   BFD_ASSERT (0);
 405   return TRUE;
 406 }
 407
 408 /* Copy any private info we understand from the input symbol
 409    to the output symbol.  */
 410
 411 static bfd_boolean
 412 bfd_plugin_bfd_copy_private_symbol_data (bfd *ibfd ATTRIBUTE_UNUSED,
 413                                          asymbol *isymbol ATTRIBUTE_UNUSED,
 414                                          bfd *obfd ATTRIBUTE_UNUSED,
 415                                          asymbol *osymbol ATTRIBUTE_UNUSED)
 416 {
 417   BFD_ASSERT (0);
 418   return TRUE;
 419 }
 420
 421 static bfd_boolean
 422 bfd_plugin_bfd_print_private_bfd_data (bfd *abfd ATTRIBUTE_UNUSED, PTR ptr ATTRIBUTE_UNUSED)
 423 {
 424   BFD_ASSERT (0);
 425   return TRUE;
 426 }
 427
 428 static char *
 429 bfd_plugin_core_file_failing_command (bfd *abfd ATTRIBUTE_UNUSED)
 430 {
 431   BFD_ASSERT (0);
 432   return NULL;
 433 }
 434
 435 static int
 436 bfd_plugin_core_file_failing_signal (bfd *abfd ATTRIBUTE_UNUSED)
 437 {
 438   BFD_ASSERT (0);
 439   return 0;
 440 }
 441
 442 static int
 443 bfd_plugin_core_file_pid (bfd *abfd ATTRIBUTE_UNUSED)
 444 {
 445   BFD_ASSERT (0);
 446   return 0;
 447 }
 448
 449 static long
 450 bfd_plugin_get_symtab_upper_bound (bfd *abfd)
 451 {
 452   struct plugin_data_struct *plugin_data = abfd->tdata.plugin_data;
 453   long nsyms = plugin_data->nsyms;
 454
 455   BFD_ASSERT (nsyms >= 0);
 456
 457   return ((nsyms + 1) * sizeof (asymbol *));
 458 }
 459
 460 static flagword
 461 convert_flags (const struct ld_plugin_symbol *sym)
 462 {
 463  switch (sym->def)
 464    {
 465    case LDPK_DEF:
 466    case LDPK_COMMON:
 467    case LDPK_UNDEF:
 468      return BSF_GLOBAL;
 469
 470    case LDPK_WEAKUNDEF:
 471    case LDPK_WEAKDEF:
 472      return BSF_GLOBAL | BSF_WEAK;
 473
 474    default:
 475      BFD_ASSERT (0);
 476      return 0;
 477    }
 478 }
 479
 480 static long
 481 bfd_plugin_canonicalize_symtab (bfd *abfd,
 482                                 asymbol **alocation)
 483 {
 484   struct plugin_data_struct *plugin_data = abfd->tdata.plugin_data;
 485   long nsyms = plugin_data->nsyms;
 486   const struct ld_plugin_symbol *syms = plugin_data->syms;
 487   static asection fake_section;
 488   static asection fake_common_section;
 489   int i;
 490
 491   fake_section.name = ".text";
 492   fake_common_section.flags = SEC_IS_COMMON;
 493
 494   for (i = 0; i < nsyms; i++)
 495     {
 496       asymbol *s = bfd_alloc (abfd, sizeof (asymbol));
 497
 498       BFD_ASSERT (s);
 499       alocation[i] = s;
 500
 501       s->the_bfd = abfd;
 502       s->name = syms[i].name;
 503       s->value = 0;
 504       s->flags = convert_flags (&syms[i]);
 505       switch (syms[i].def)
 506         {
 507         case LDPK_COMMON:
 508           s->section = &fake_common_section;
 509           break;
 510         case LDPK_UNDEF:
 511         case LDPK_WEAKUNDEF:
 512           s->section = bfd_und_section_ptr;
 513           break;
 514         case LDPK_DEF:
 515         case LDPK_WEAKDEF:
 516           s->section = &fake_section;
 517           break;
 518         default:
 519           BFD_ASSERT (0);
 520         }
 521
 522       s->udata.p = (void *) &syms[i];
 523     }
 524
 525   return nsyms;
 526 }
 527
 528 static void
 529 bfd_plugin_print_symbol (bfd *abfd ATTRIBUTE_UNUSED,
 530                          PTR afile ATTRIBUTE_UNUSED,
 531                          asymbol *symbol ATTRIBUTE_UNUSED,
 532                          bfd_print_symbol_type how ATTRIBUTE_UNUSED)
 533 {
 534   BFD_ASSERT (0);
 535 }
 536
 537 static void
 538 bfd_plugin_get_symbol_info (bfd *abfd ATTRIBUTE_UNUSED,
 539                             asymbol *symbol,
 540                             symbol_info *ret)
 541 {
 542   bfd_symbol_info (symbol, ret);
 543 }
 544
 545 /* Make an empty symbol. */
 546
 547 static asymbol *
 548 bfd_plugin_make_empty_symbol (bfd *abfd)
 549 {
 550   asymbol *new_symbol = bfd_zalloc (abfd, sizeof (asymbol));
 551   if (new_symbol == NULL)
 552     return new_symbol;
 553   new_symbol->the_bfd = abfd;
 554   return new_symbol;
 555 }
 556
 557 static int
 558 bfd_plugin_sizeof_headers (bfd *a ATTRIBUTE_UNUSED,
 559                            struct bfd_link_info *info ATTRIBUTE_UNUSED)
 560 {
 561   BFD_ASSERT (0);
 562   return 0;
 563 }
 564
 565 const bfd_target plugin_vec =
 566 {
 567   "plugin",                     /* Name.  */
 568   bfd_target_unknown_flavour,
 569   BFD_ENDIAN_LITTLE,            /* Target byte order.  */
 570   BFD_ENDIAN_LITTLE,            /* Target headers byte order.  */
 571   (HAS_RELOC | EXEC_P |         /* Object flags.  */
 572    HAS_LINENO | HAS_DEBUG |
 573    HAS_SYMS | HAS_LOCALS | DYNAMIC | WP_TEXT | D_PAGED),
 574   (SEC_CODE | SEC_DATA | SEC_ROM | SEC_HAS_CONTENTS
 575    | SEC_ALLOC | SEC_LOAD | SEC_RELOC), /* Section flags.  */
 576   0,                            /* symbol_leading_char.  */
 577   '/',                          /* ar_pad_char.  */
 578   15,                           /* ar_max_namelen.  */
 579   255,                          /* match priority.  */
 580
 581   bfd_getl64, bfd_getl_signed_64, bfd_putl64,
 582   bfd_getl32, bfd_getl_signed_32, bfd_putl32,
 583   bfd_getl16, bfd_getl_signed_16, bfd_putl16,   /* data */
 584   bfd_getl64, bfd_getl_signed_64, bfd_putl64,
 585   bfd_getl32, bfd_getl_signed_32, bfd_putl32,
 586   bfd_getl16, bfd_getl_signed_16, bfd_putl16,   /* hdrs */
 587
 588   {                             /* bfd_check_format.  */
 589     _bfd_dummy_target,
 590     bfd_plugin_object_p,
 591     bfd_generic_archive_p,
 592     _bfd_dummy_target
 593   },
 594   {                             /* bfd_set_format.  */
 595     bfd_false,
 596     bfd_false,
 597     _bfd_generic_mkarchive,
 598     bfd_false,
 599   },
 600   {                             /* bfd_write_contents.  */
 601     bfd_false,
 602     bfd_false,
 603     _bfd_write_archive_contents,
 604     bfd_false,
 605   },
 606
 607   BFD_JUMP_TABLE_GENERIC (bfd_plugin),
 608   BFD_JUMP_TABLE_COPY (bfd_plugin),
 609   BFD_JUMP_TABLE_CORE (bfd_plugin),
 610 #ifdef USE_64_BIT_ARCHIVE
 611   BFD_JUMP_TABLE_ARCHIVE (_bfd_archive_64_bit),
 612 #else
 613   BFD_JUMP_TABLE_ARCHIVE (_bfd_archive_coff),
 614 #endif
 615   BFD_JUMP_TABLE_SYMBOLS (bfd_plugin),
 616   BFD_JUMP_TABLE_RELOCS (_bfd_norelocs),
 617   BFD_JUMP_TABLE_WRITE (bfd_plugin),
 618   BFD_JUMP_TABLE_LINK (bfd_plugin),
 619   BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic),
 620
 621   NULL,
 622
 623   NULL                          /* backend_data.  */
 624 };
 625 #endif /* BFD_SUPPORTS_PLUGIN */