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_bfd_make_debug_symbol              _bfd_nosymbols_bfd_make_debug_symbol
  89 #define bfd_plugin_read_minisymbols                   _bfd_generic_read_minisymbols
  90 #define bfd_plugin_minisymbol_to_symbol               _bfd_generic_minisymbol_to_symbol
  91 #define bfd_plugin_set_arch_mach                      bfd_default_set_arch_mach
  92 #define bfd_plugin_set_section_contents               _bfd_generic_set_section_contents
  93 #define bfd_plugin_bfd_get_relocated_section_contents bfd_generic_get_relocated_section_contents
  94 #define bfd_plugin_bfd_relax_section                  bfd_generic_relax_section
  95 #define bfd_plugin_bfd_link_hash_table_create         _bfd_generic_link_hash_table_create
  96 #define bfd_plugin_bfd_link_add_symbols               _bfd_generic_link_add_symbols
  97 #define bfd_plugin_bfd_link_just_syms                 _bfd_generic_link_just_syms
  98 #define bfd_plugin_bfd_final_link                     _bfd_generic_final_link
  99 #define bfd_plugin_bfd_link_split_section             _bfd_generic_link_split_section
 100 #define bfd_plugin_bfd_gc_sections                    bfd_generic_gc_sections
 101 #define bfd_plugin_bfd_lookup_section_flags           bfd_generic_lookup_section_flags
 102 #define bfd_plugin_bfd_merge_sections                 bfd_generic_merge_sections
 103 #define bfd_plugin_bfd_is_group_section               bfd_generic_is_group_section
 104 #define bfd_plugin_bfd_discard_group                  bfd_generic_discard_group
 105 #define bfd_plugin_section_already_linked             _bfd_generic_section_already_linked
 106 #define bfd_plugin_bfd_define_common_symbol           bfd_generic_define_common_symbol
 107 #define bfd_plugin_bfd_copy_link_hash_symbol_type     _bfd_generic_copy_link_hash_symbol_type
 108
 109 static enum ld_plugin_status
 110 message (int level ATTRIBUTE_UNUSED,
 111          const char * format, ...)
 112 {
 113   va_list args;
 114   va_start (args, format);
 115   printf ("bfd plugin: ");
 116   vprintf (format, args);
 117   putchar ('\n');
 118   va_end (args);
 119   return LDPS_OK;
 120 }
 121
 122 /* Register a claim-file handler. */
 123 static ld_plugin_claim_file_handler claim_file;
 124
 125 static enum ld_plugin_status
 126 register_claim_file (ld_plugin_claim_file_handler handler)
 127 {
 128   claim_file = handler;
 129   return LDPS_OK;
 130 }
 131
 132 static enum ld_plugin_status
 133 add_symbols (void * handle,
 134              int nsyms,
 135              const struct ld_plugin_symbol * syms)
 136 {
 137   bfd *abfd = handle;
 138   struct plugin_data_struct *plugin_data =
 139     bfd_alloc (abfd, sizeof (plugin_data_struct));
 140
 141   plugin_data->nsyms = nsyms;
 142   plugin_data->syms = syms;
 143
 144   if (nsyms != 0)
 145     abfd->flags |= HAS_SYMS;
 146
 147   abfd->tdata.plugin_data = plugin_data;
 148   return LDPS_OK;
 149 }
 150
 151 static const char *plugin_program_name;
 152
 153 void
 154 bfd_plugin_set_program_name (const char *program_name)
 155 {
 156   plugin_program_name = program_name;
 157 }
 158
 159 static int
 160 try_claim (bfd *abfd)
 161 {
 162   int claimed = 0;
 163   struct ld_plugin_input_file file;
 164   bfd *iobfd;
 165
 166   file.name = abfd->filename;
 167
 168   if (abfd->my_archive)
 169     {
 170       iobfd = abfd->my_archive;
 171       file.offset = abfd->origin;
 172       file.filesize = arelt_size (abfd);
 173     }
 174   else
 175     {
 176       iobfd = abfd;
 177       file.offset = 0;
 178       file.filesize = 0;
 179     }
 180
 181   if (!iobfd->iostream && !bfd_open_file (iobfd))
 182     return 0;
 183
 184   file.fd = fileno ((FILE *) iobfd->iostream);
 185
 186   if (!abfd->my_archive)
 187     {
 188       struct stat stat_buf;
 189       if (fstat (file.fd, &stat_buf))
 190         return 0;
 191       file.filesize = stat_buf.st_size;
 192     }
 193
 194   file.handle = abfd;
 195   off_t cur_offset = lseek(file.fd, 0, SEEK_CUR);
 196   claim_file (&file, &claimed);
 197   lseek(file.fd, cur_offset, SEEK_SET);
 198   if (!claimed)
 199     return 0;
 200
 201   return 1;
 202 }
 203
 204 static int
 205 try_load_plugin (const char *pname, bfd *abfd)
 206 {
 207   void *plugin_handle;
 208   int tv_size = 4;
 209   struct ld_plugin_tv tv[tv_size];
 210   int i;
 211   ld_plugin_onload onload;
 212   enum ld_plugin_status status;
 213
 214   plugin_handle = dlopen (pname, RTLD_NOW);
 215   if (!plugin_handle)
 216     {
 217       (*_bfd_error_handler)("%s\n", dlerror ());
 218       return 0;
 219     }
 220
 221   onload = dlsym (plugin_handle, "onload");
 222   if (!onload)
 223     goto err;
 224
 225   i = 0;
 226   tv[i].tv_tag = LDPT_MESSAGE;
 227   tv[i].tv_u.tv_message = message;
 228
 229   ++i;
 230   tv[i].tv_tag = LDPT_REGISTER_CLAIM_FILE_HOOK;
 231   tv[i].tv_u.tv_register_claim_file = register_claim_file;
 232
 233   ++i;
 234   tv[i].tv_tag = LDPT_ADD_SYMBOLS;
 235   tv[i].tv_u.tv_add_symbols = add_symbols;
 236
 237   ++i;
 238   tv[i].tv_tag = LDPT_NULL;
 239   tv[i].tv_u.tv_val = 0;
 240
 241   status = (*onload)(tv);
 242
 243   if (status != LDPS_OK)
 244     goto err;
 245
 246   if (!claim_file)
 247     goto err;
 248
 249   if (!try_claim (abfd))
 250     goto err;
 251
 252   return 1;
 253
 254  err:
 255   plugin_handle = NULL;
 256   return 0;
 257 }
 258
 259 static const char *plugin_name;
 260
 261 void
 262 bfd_plugin_set_plugin (const char *p)
 263 {
 264   plugin_name = p;
 265 }
 266
 267 static int
 268 load_plugin (bfd *abfd)
 269 {
 270   char *plugin_dir;
 271   char *p;
 272   DIR *d;
 273   struct dirent *ent;
 274   int found = 0;
 275
 276   if (plugin_name)
 277     return try_load_plugin (plugin_name, abfd);
 278
 279   if (plugin_program_name == NULL)
 280     return 0;
 281
 282   plugin_dir = concat (BINDIR, "/../lib/bfd-plugins", NULL);
 283   p = make_relative_prefix (plugin_program_name,
 284                             BINDIR,
 285                             plugin_dir);
 286   free (plugin_dir);
 287   plugin_dir = NULL;
 288
 289   d = opendir (p);
 290   if (!d)
 291     goto out;
 292
 293   while ((ent = readdir (d)))
 294     {
 295       char *full_name;
 296       struct stat s;
 297
 298       full_name = concat (p, "/", ent->d_name, NULL);
 299       if (stat(full_name, &s) == 0 && S_ISREG (s.st_mode))
 300         found = try_load_plugin (full_name, abfd);
 301       free (full_name);
 302       if (found)
 303         break;
 304     }
 305
 306  out:
 307   free (p);
 308   if (d)
 309     closedir (d);
 310
 311   return found;
 312 }
 313
 314
 315 static const bfd_target *
 316 bfd_plugin_object_p (bfd *abfd)
 317 {
 318   if (!load_plugin (abfd))
 319     return NULL;
 320
 321   return abfd->xvec;
 322 }
 323
 324 /* Copy any private info we understand from the input bfd
 325    to the output bfd.  */
 326
 327 static bfd_boolean
 328 bfd_plugin_bfd_copy_private_bfd_data (bfd *ibfd ATTRIBUTE_UNUSED,
 329                                       bfd *obfd ATTRIBUTE_UNUSED)
 330 {
 331   BFD_ASSERT (0);
 332   return TRUE;
 333 }
 334
 335 /* Copy any private info we understand from the input section
 336    to the output section.  */
 337
 338 static bfd_boolean
 339 bfd_plugin_bfd_copy_private_section_data (bfd *ibfd ATTRIBUTE_UNUSED,
 340                                           asection *isection ATTRIBUTE_UNUSED,
 341                                           bfd *obfd ATTRIBUTE_UNUSED,
 342                                           asection *osection ATTRIBUTE_UNUSED)
 343 {
 344   BFD_ASSERT (0);
 345   return TRUE;
 346 }
 347
 348 /* Copy any private info we understand from the input symbol
 349    to the output symbol.  */
 350
 351 static bfd_boolean
 352 bfd_plugin_bfd_copy_private_symbol_data (bfd *ibfd ATTRIBUTE_UNUSED,
 353                                          asymbol *isymbol ATTRIBUTE_UNUSED,
 354                                          bfd *obfd ATTRIBUTE_UNUSED,
 355                                          asymbol *osymbol ATTRIBUTE_UNUSED)
 356 {
 357   BFD_ASSERT (0);
 358   return TRUE;
 359 }
 360
 361 static bfd_boolean
 362 bfd_plugin_bfd_print_private_bfd_data (bfd *abfd ATTRIBUTE_UNUSED, PTR ptr ATTRIBUTE_UNUSED)
 363 {
 364   BFD_ASSERT (0);
 365   return TRUE;
 366 }
 367
 368 static char *
 369 bfd_plugin_core_file_failing_command (bfd *abfd ATTRIBUTE_UNUSED)
 370 {
 371   BFD_ASSERT (0);
 372   return NULL;
 373 }
 374
 375 static int
 376 bfd_plugin_core_file_failing_signal (bfd *abfd ATTRIBUTE_UNUSED)
 377 {
 378   BFD_ASSERT (0);
 379   return 0;
 380 }
 381
 382 static int
 383 bfd_plugin_core_file_pid (bfd *abfd ATTRIBUTE_UNUSED)
 384 {
 385   BFD_ASSERT (0);
 386   return 0;
 387 }
 388
 389 static long
 390 bfd_plugin_get_symtab_upper_bound (bfd *abfd)
 391 {
 392   struct plugin_data_struct *plugin_data = abfd->tdata.plugin_data;
 393   long nsyms = plugin_data->nsyms;
 394
 395   BFD_ASSERT (nsyms >= 0);
 396
 397   return ((nsyms + 1) * sizeof (asymbol *));
 398 }
 399
 400 static flagword
 401 convert_flags (const struct ld_plugin_symbol *sym)
 402 {
 403  switch (sym->def)
 404    {
 405    case LDPK_DEF:
 406    case LDPK_COMMON:
 407    case LDPK_UNDEF:
 408      return BSF_GLOBAL;
 409
 410    case LDPK_WEAKUNDEF:
 411    case LDPK_WEAKDEF:
 412      return BSF_GLOBAL | BSF_WEAK;
 413
 414    default:
 415      BFD_ASSERT (0);
 416      return 0;
 417    }
 418 }
 419
 420 static long
 421 bfd_plugin_canonicalize_symtab (bfd *abfd,
 422                                 asymbol **alocation)
 423 {
 424   struct plugin_data_struct *plugin_data = abfd->tdata.plugin_data;
 425   long nsyms = plugin_data->nsyms;
 426   const struct ld_plugin_symbol *syms = plugin_data->syms;
 427   static asection fake_section;
 428   static asection fake_common_section;
 429   int i;
 430
 431   fake_section.name = ".text";
 432   fake_common_section.flags = SEC_IS_COMMON;
 433
 434   for (i = 0; i < nsyms; i++)
 435     {
 436       asymbol *s = bfd_alloc (abfd, sizeof (asymbol));
 437
 438       BFD_ASSERT (s);
 439       alocation[i] = s;
 440
 441       s->the_bfd = abfd;
 442       s->name = syms[i].name;
 443       s->value = 0;
 444       s->flags = convert_flags (&syms[i]);
 445       switch (syms[i].def)
 446         {
 447         case LDPK_COMMON:
 448           s->section = &fake_common_section;
 449           break;
 450         case LDPK_UNDEF:
 451         case LDPK_WEAKUNDEF:
 452           s->section = bfd_und_section_ptr;
 453           break;
 454         case LDPK_DEF:
 455         case LDPK_WEAKDEF:
 456           s->section = &fake_section;
 457           break;
 458         default:
 459           BFD_ASSERT (0);
 460         }
 461
 462       s->udata.p = (void *) &syms[i];
 463     }
 464
 465   return nsyms;
 466 }
 467
 468 static void
 469 bfd_plugin_print_symbol (bfd *abfd ATTRIBUTE_UNUSED,
 470                          PTR afile ATTRIBUTE_UNUSED,
 471                          asymbol *symbol ATTRIBUTE_UNUSED,
 472                          bfd_print_symbol_type how ATTRIBUTE_UNUSED)
 473 {
 474   BFD_ASSERT (0);
 475 }
 476
 477 static void
 478 bfd_plugin_get_symbol_info (bfd *abfd ATTRIBUTE_UNUSED,
 479                             asymbol *symbol,
 480                             symbol_info *ret)
 481 {
 482   bfd_symbol_info (symbol, ret);
 483 }
 484
 485 /* Make an empty symbol. */
 486
 487 static asymbol *
 488 bfd_plugin_make_empty_symbol (bfd *abfd)
 489 {
 490   asymbol *new_symbol = bfd_zalloc (abfd, sizeof (asymbol));
 491   if (new_symbol == NULL)
 492     return new_symbol;
 493   new_symbol->the_bfd = abfd;
 494   return new_symbol;
 495 }
 496
 497 static int
 498 bfd_plugin_sizeof_headers (bfd *a ATTRIBUTE_UNUSED,
 499                            struct bfd_link_info *info ATTRIBUTE_UNUSED)
 500 {
 501   BFD_ASSERT (0);
 502   return 0;
 503 }
 504
 505 const bfd_target plugin_vec =
 506 {
 507   "plugin",                     /* Name.  */
 508   bfd_target_unknown_flavour,
 509   BFD_ENDIAN_LITTLE,            /* Target byte order.  */
 510   BFD_ENDIAN_LITTLE,            /* Target headers byte order.  */
 511   (HAS_RELOC | EXEC_P |         /* Object flags.  */
 512    HAS_LINENO | HAS_DEBUG |
 513    HAS_SYMS | HAS_LOCALS | DYNAMIC | WP_TEXT | D_PAGED),
 514   (SEC_CODE | SEC_DATA | SEC_ROM | SEC_HAS_CONTENTS
 515    | SEC_ALLOC | SEC_LOAD | SEC_RELOC), /* Section flags.  */
 516   0,                            /* symbol_leading_char.  */
 517   '/',                          /* ar_pad_char.  */
 518   15,                           /* ar_max_namelen.  */
 519   0,                            /* match priority.  */
 520
 521   bfd_getl64, bfd_getl_signed_64, bfd_putl64,
 522   bfd_getl32, bfd_getl_signed_32, bfd_putl32,
 523   bfd_getl16, bfd_getl_signed_16, bfd_putl16,   /* data */
 524   bfd_getl64, bfd_getl_signed_64, bfd_putl64,
 525   bfd_getl32, bfd_getl_signed_32, bfd_putl32,
 526   bfd_getl16, bfd_getl_signed_16, bfd_putl16,   /* hdrs */
 527
 528   {                             /* bfd_check_format.  */
 529     _bfd_dummy_target,
 530     bfd_plugin_object_p,
 531     bfd_generic_archive_p,
 532     _bfd_dummy_target
 533   },
 534   {                             /* bfd_set_format.  */
 535     bfd_false,
 536     bfd_false,
 537     _bfd_generic_mkarchive,
 538     bfd_false,
 539   },
 540   {                             /* bfd_write_contents.  */
 541     bfd_false,
 542     bfd_false,
 543     _bfd_write_archive_contents,
 544     bfd_false,
 545   },
 546
 547   BFD_JUMP_TABLE_GENERIC (bfd_plugin),
 548   BFD_JUMP_TABLE_COPY (bfd_plugin),
 549   BFD_JUMP_TABLE_CORE (bfd_plugin),
 550   BFD_JUMP_TABLE_ARCHIVE (_bfd_archive_coff),
 551   BFD_JUMP_TABLE_SYMBOLS (bfd_plugin),
 552   BFD_JUMP_TABLE_RELOCS (_bfd_norelocs),
 553   BFD_JUMP_TABLE_WRITE (bfd_plugin),
 554   BFD_JUMP_TABLE_LINK (bfd_plugin),
 555   BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic),
 556
 557   NULL,
 558
 559   NULL                          /* backend_data.  */
 560 };
 561 #endif /* BFD_SUPPORTS_PLUGIN */