bfd/plugin.c

   1 /* Plugin support for BFD.
   2    Copyright (C) 2009-2014 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
 110 static enum ld_plugin_status
 111 message (int level ATTRIBUTE_UNUSED,
 112          const char * format, ...)
 113 {
 114   va_list args;
 115   va_start (args, format);
 116   printf ("bfd plugin: ");
 117   vprintf (format, args);
 118   putchar ('\n');
 119   va_end (args);
 120   return LDPS_OK;
 121 }
 122
 123 /* Register a claim-file handler. */
 124 static ld_plugin_claim_file_handler claim_file;
 125
 126 static enum ld_plugin_status
 127 register_claim_file (ld_plugin_claim_file_handler handler)
 128 {
 129   claim_file = handler;
 130   return LDPS_OK;
 131 }
 132
 133 static enum ld_plugin_status
 134 add_symbols (void * handle,
 135              int nsyms,
 136              const struct ld_plugin_symbol * syms)
 137 {
 138   bfd *abfd = handle;
 139   struct plugin_data_struct *plugin_data =
 140     bfd_alloc (abfd, sizeof (plugin_data_struct));
 141
 142   plugin_data->nsyms = nsyms;
 143   plugin_data->syms = syms;
 144
 145   if (nsyms != 0)
 146     abfd->flags |= HAS_SYMS;
 147
 148   abfd->tdata.plugin_data = plugin_data;
 149   return LDPS_OK;
 150 }
 151
 152 static const char *plugin_program_name;
 153
 154 void
 155 bfd_plugin_set_program_name (const char *program_name)
 156 {
 157   plugin_program_name = program_name;
 158 }
 159
 160 static int
 161 try_claim (bfd *abfd)
 162 {
 163   int claimed = 0;
 164   struct ld_plugin_input_file file;
 165   bfd *iobfd;
 166
 167   file.name = abfd->filename;
 168
 169   if (abfd->my_archive)
 170     {
 171       iobfd = abfd->my_archive;
 172       file.offset = abfd->origin;
 173       file.filesize = arelt_size (abfd);
 174     }
 175   else
 176     {
 177       iobfd = abfd;
 178       file.offset = 0;
 179       file.filesize = 0;
 180     }
 181
 182   if (!iobfd->iostream && !bfd_open_file (iobfd))
 183     return 0;
 184
 185   file.fd = fileno ((FILE *) iobfd->iostream);
 186
 187   if (!abfd->my_archive)
 188     {
 189       struct stat stat_buf;
 190       if (fstat (file.fd, &stat_buf))
 191         return 0;
 192       file.filesize = stat_buf.st_size;
 193     }
 194
 195   file.handle = abfd;
 196   off_t cur_offset = lseek(file.fd, 0, SEEK_CUR);
 197   claim_file (&file, &claimed);
 198   lseek(file.fd, cur_offset, SEEK_SET);
 199   if (!claimed)
 200     return 0;
 201
 202   return 1;
 203 }
 204
 205 static int
 206 try_load_plugin (const char *pname, bfd *abfd)
 207 {
 208   void *plugin_handle;
 209   int tv_size = 4;
 210   struct ld_plugin_tv tv[tv_size];
 211   int i;
 212   ld_plugin_onload onload;
 213   enum ld_plugin_status status;
 214
 215   plugin_handle = dlopen (pname, RTLD_NOW);
 216   if (!plugin_handle)
 217     {
 218       (*_bfd_error_handler)("%s\n", dlerror ());
 219       return 0;
 220     }
 221
 222   onload = dlsym (plugin_handle, "onload");
 223   if (!onload)
 224     goto err;
 225
 226   i = 0;
 227   tv[i].tv_tag = LDPT_MESSAGE;
 228   tv[i].tv_u.tv_message = message;
 229
 230   ++i;
 231   tv[i].tv_tag = LDPT_REGISTER_CLAIM_FILE_HOOK;
 232   tv[i].tv_u.tv_register_claim_file = register_claim_file;
 233
 234   ++i;
 235   tv[i].tv_tag = LDPT_ADD_SYMBOLS;
 236   tv[i].tv_u.tv_add_symbols = add_symbols;
 237
 238   ++i;
 239   tv[i].tv_tag = LDPT_NULL;
 240   tv[i].tv_u.tv_val = 0;
 241
 242   status = (*onload)(tv);
 243
 244   if (status != LDPS_OK)
 245     goto err;
 246
 247   if (!claim_file)
 248     goto err;
 249
 250   if (!try_claim (abfd))
 251     goto err;
 252
 253   return 1;
 254
 255  err:
 256   plugin_handle = NULL;
 257   return 0;
 258 }
 259
 260 static const char *plugin_name;
 261
 262 void
 263 bfd_plugin_set_plugin (const char *p)
 264 {
 265   plugin_name = p;
 266 }
 267
 268 static int
 269 load_plugin (bfd *abfd)
 270 {
 271   char *plugin_dir;
 272   char *p;
 273   DIR *d;
 274   struct dirent *ent;
 275   int found = 0;
 276
 277   if (plugin_name)
 278     return try_load_plugin (plugin_name, abfd);
 279
 280   if (plugin_program_name == NULL)
 281     return 0;
 282
 283   plugin_dir = concat (BINDIR, "/../lib/bfd-plugins", NULL);
 284   p = make_relative_prefix (plugin_program_name,
 285                             BINDIR,
 286                             plugin_dir);
 287   free (plugin_dir);
 288   plugin_dir = NULL;
 289
 290   d = opendir (p);
 291   if (!d)
 292     goto out;
 293
 294   while ((ent = readdir (d)))
 295     {
 296       char *full_name;
 297       struct stat s;
 298
 299       full_name = concat (p, "/", ent->d_name, NULL);
 300       if (stat(full_name, &s) == 0 && S_ISREG (s.st_mode))
 301         found = try_load_plugin (full_name, abfd);
 302       free (full_name);
 303       if (found)
 304         break;
 305     }
 306
 307  out:
 308   free (p);
 309   if (d)
 310     closedir (d);
 311
 312   return found;
 313 }
 314
 315
 316 static const bfd_target *
 317 bfd_plugin_object_p (bfd *abfd)
 318 {
 319   if (!load_plugin (abfd))
 320     return NULL;
 321
 322   return abfd->xvec;
 323 }
 324
 325 /* Copy any private info we understand from the input bfd
 326    to the output bfd.  */
 327
 328 static bfd_boolean
 329 bfd_plugin_bfd_copy_private_bfd_data (bfd *ibfd ATTRIBUTE_UNUSED,
 330                                       bfd *obfd ATTRIBUTE_UNUSED)
 331 {
 332   BFD_ASSERT (0);
 333   return TRUE;
 334 }
 335
 336 /* Copy any private info we understand from the input section
 337    to the output section.  */
 338
 339 static bfd_boolean
 340 bfd_plugin_bfd_copy_private_section_data (bfd *ibfd ATTRIBUTE_UNUSED,
 341                                           asection *isection ATTRIBUTE_UNUSED,
 342                                           bfd *obfd ATTRIBUTE_UNUSED,
 343                                           asection *osection ATTRIBUTE_UNUSED)
 344 {
 345   BFD_ASSERT (0);
 346   return TRUE;
 347 }
 348
 349 /* Copy any private info we understand from the input symbol
 350    to the output symbol.  */
 351
 352 static bfd_boolean
 353 bfd_plugin_bfd_copy_private_symbol_data (bfd *ibfd ATTRIBUTE_UNUSED,
 354                                          asymbol *isymbol ATTRIBUTE_UNUSED,
 355                                          bfd *obfd ATTRIBUTE_UNUSED,
 356                                          asymbol *osymbol ATTRIBUTE_UNUSED)
 357 {
 358   BFD_ASSERT (0);
 359   return TRUE;
 360 }
 361
 362 static bfd_boolean
 363 bfd_plugin_bfd_print_private_bfd_data (bfd *abfd ATTRIBUTE_UNUSED, PTR ptr ATTRIBUTE_UNUSED)
 364 {
 365   BFD_ASSERT (0);
 366   return TRUE;
 367 }
 368
 369 static char *
 370 bfd_plugin_core_file_failing_command (bfd *abfd ATTRIBUTE_UNUSED)
 371 {
 372   BFD_ASSERT (0);
 373   return NULL;
 374 }
 375
 376 static int
 377 bfd_plugin_core_file_failing_signal (bfd *abfd ATTRIBUTE_UNUSED)
 378 {
 379   BFD_ASSERT (0);
 380   return 0;
 381 }
 382
 383 static int
 384 bfd_plugin_core_file_pid (bfd *abfd ATTRIBUTE_UNUSED)
 385 {
 386   BFD_ASSERT (0);
 387   return 0;
 388 }
 389
 390 static long
 391 bfd_plugin_get_symtab_upper_bound (bfd *abfd)
 392 {
 393   struct plugin_data_struct *plugin_data = abfd->tdata.plugin_data;
 394   long nsyms = plugin_data->nsyms;
 395
 396   BFD_ASSERT (nsyms >= 0);
 397
 398   return ((nsyms + 1) * sizeof (asymbol *));
 399 }
 400
 401 static flagword
 402 convert_flags (const struct ld_plugin_symbol *sym)
 403 {
 404  switch (sym->def)
 405    {
 406    case LDPK_DEF:
 407    case LDPK_COMMON:
 408    case LDPK_UNDEF:
 409      return BSF_GLOBAL;
 410
 411    case LDPK_WEAKUNDEF:
 412    case LDPK_WEAKDEF:
 413      return BSF_GLOBAL | BSF_WEAK;
 414
 415    default:
 416      BFD_ASSERT (0);
 417      return 0;
 418    }
 419 }
 420
 421 static long
 422 bfd_plugin_canonicalize_symtab (bfd *abfd,
 423                                 asymbol **alocation)
 424 {
 425   struct plugin_data_struct *plugin_data = abfd->tdata.plugin_data;
 426   long nsyms = plugin_data->nsyms;
 427   const struct ld_plugin_symbol *syms = plugin_data->syms;
 428   static asection fake_section;
 429   static asection fake_common_section;
 430   int i;
 431
 432   fake_section.name = ".text";
 433   fake_common_section.flags = SEC_IS_COMMON;
 434
 435   for (i = 0; i < nsyms; i++)
 436     {
 437       asymbol *s = bfd_alloc (abfd, sizeof (asymbol));
 438
 439       BFD_ASSERT (s);
 440       alocation[i] = s;
 441
 442       s->the_bfd = abfd;
 443       s->name = syms[i].name;
 444       s->value = 0;
 445       s->flags = convert_flags (&syms[i]);
 446       switch (syms[i].def)
 447         {
 448         case LDPK_COMMON:
 449           s->section = &fake_common_section;
 450           break;
 451         case LDPK_UNDEF:
 452         case LDPK_WEAKUNDEF:
 453           s->section = bfd_und_section_ptr;
 454           break;
 455         case LDPK_DEF:
 456         case LDPK_WEAKDEF:
 457           s->section = &fake_section;
 458           break;
 459         default:
 460           BFD_ASSERT (0);
 461         }
 462
 463       s->udata.p = (void *) &syms[i];
 464     }
 465
 466   return nsyms;
 467 }
 468
 469 static void
 470 bfd_plugin_print_symbol (bfd *abfd ATTRIBUTE_UNUSED,
 471                          PTR afile ATTRIBUTE_UNUSED,
 472                          asymbol *symbol ATTRIBUTE_UNUSED,
 473                          bfd_print_symbol_type how ATTRIBUTE_UNUSED)
 474 {
 475   BFD_ASSERT (0);
 476 }
 477
 478 static void
 479 bfd_plugin_get_symbol_info (bfd *abfd ATTRIBUTE_UNUSED,
 480                             asymbol *symbol,
 481                             symbol_info *ret)
 482 {
 483   bfd_symbol_info (symbol, ret);
 484 }
 485
 486 /* Make an empty symbol. */
 487
 488 static asymbol *
 489 bfd_plugin_make_empty_symbol (bfd *abfd)
 490 {
 491   asymbol *new_symbol = bfd_zalloc (abfd, sizeof (asymbol));
 492   if (new_symbol == NULL)
 493     return new_symbol;
 494   new_symbol->the_bfd = abfd;
 495   return new_symbol;
 496 }
 497
 498 static int
 499 bfd_plugin_sizeof_headers (bfd *a ATTRIBUTE_UNUSED,
 500                            struct bfd_link_info *info ATTRIBUTE_UNUSED)
 501 {
 502   BFD_ASSERT (0);
 503   return 0;
 504 }
 505
 506 const bfd_target plugin_vec =
 507 {
 508   "plugin",                     /* Name.  */
 509   bfd_target_unknown_flavour,
 510   BFD_ENDIAN_LITTLE,            /* Target byte order.  */
 511   BFD_ENDIAN_LITTLE,            /* Target headers byte order.  */
 512   (HAS_RELOC | EXEC_P |         /* Object flags.  */
 513    HAS_LINENO | HAS_DEBUG |
 514    HAS_SYMS | HAS_LOCALS | DYNAMIC | WP_TEXT | D_PAGED),
 515   (SEC_CODE | SEC_DATA | SEC_ROM | SEC_HAS_CONTENTS
 516    | SEC_ALLOC | SEC_LOAD | SEC_RELOC), /* Section flags.  */
 517   0,                            /* symbol_leading_char.  */
 518   '/',                          /* ar_pad_char.  */
 519   15,                           /* ar_max_namelen.  */
 520   0,                            /* match priority.  */
 521
 522   bfd_getl64, bfd_getl_signed_64, bfd_putl64,
 523   bfd_getl32, bfd_getl_signed_32, bfd_putl32,
 524   bfd_getl16, bfd_getl_signed_16, bfd_putl16,   /* data */
 525   bfd_getl64, bfd_getl_signed_64, bfd_putl64,
 526   bfd_getl32, bfd_getl_signed_32, bfd_putl32,
 527   bfd_getl16, bfd_getl_signed_16, bfd_putl16,   /* hdrs */
 528
 529   {                             /* bfd_check_format.  */
 530     _bfd_dummy_target,
 531     bfd_plugin_object_p,
 532     bfd_generic_archive_p,
 533     _bfd_dummy_target
 534   },
 535   {                             /* bfd_set_format.  */
 536     bfd_false,
 537     bfd_false,
 538     _bfd_generic_mkarchive,
 539     bfd_false,
 540   },
 541   {                             /* bfd_write_contents.  */
 542     bfd_false,
 543     bfd_false,
 544     _bfd_write_archive_contents,
 545     bfd_false,
 546   },
 547
 548   BFD_JUMP_TABLE_GENERIC (bfd_plugin),
 549   BFD_JUMP_TABLE_COPY (bfd_plugin),
 550   BFD_JUMP_TABLE_CORE (bfd_plugin),
 551   BFD_JUMP_TABLE_ARCHIVE (_bfd_archive_coff),
 552   BFD_JUMP_TABLE_SYMBOLS (bfd_plugin),
 553   BFD_JUMP_TABLE_RELOCS (_bfd_norelocs),
 554   BFD_JUMP_TABLE_WRITE (bfd_plugin),
 555   BFD_JUMP_TABLE_LINK (bfd_plugin),
 556   BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic),
 557
 558   NULL,
 559
 560   NULL                          /* backend_data.  */
 561 };
 562 #endif /* BFD_SUPPORTS_PLUGIN */