bfd/plugin.c

   1 /* Plugin support for BFD.
   2    Copyright 2009, 2010, 2011, 2012
   3    Free Software Foundation, Inc.
   4
   5    This file is part of BFD, the Binary File Descriptor library.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, write to the Free Software
  19    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  20    MA 02110-1301, USA.  */
  21
  22 #include "sysdep.h"
  23 #include "bfd.h"
  24
  25 #if BFD_SUPPORTS_PLUGINS
  26
  27 #include <assert.h>
  28 #ifdef HAVE_DLFCN_H
  29 #include <dlfcn.h>
  30 #elif defined (HAVE_WINDOWS_H)
  31 #include <windows.h>
  32 #else
  33 #error Unknown how to handle dynamic-load-libraries.
  34 #endif
  35 #include <stdarg.h>
  36 #include "plugin-api.h"
  37 #include "plugin.h"
  38 #include "libbfd.h"
  39 #include "libiberty.h"
  40 #include <dirent.h>
  41
  42 #if !defined (HAVE_DLFCN_H) && defined (HAVE_WINDOWS_H)
  43
  44 #define RTLD_NOW 0      /* Dummy value.  */
  45
  46 static void *
  47 dlopen (const char *file, int mode ATTRIBUTE_UNUSED)
  48 {
  49   return LoadLibrary (file);
  50 }
  51
  52 static void *
  53 dlsym (void *handle, const char *name)
  54 {
  55   return GetProcAddress (handle, name);
  56 }
  57
  58 static int ATTRIBUTE_UNUSED
  59 dlclose (void *handle)
  60 {
  61   FreeLibrary (handle);
  62   return 0;
  63 }
  64
  65 static const char *
  66 dlerror (void)
  67 {
  68   return "Unable to load DLL.";
  69 }
  70
  71 #endif /* !defined (HAVE_DLFCN_H) && defined (HAVE_WINDOWS_H)  */
  72
  73 #define bfd_plugin_close_and_cleanup                  _bfd_generic_close_and_cleanup
  74 #define bfd_plugin_bfd_free_cached_info               _bfd_generic_bfd_free_cached_info
  75 #define bfd_plugin_new_section_hook                   _bfd_generic_new_section_hook
  76 #define bfd_plugin_get_section_contents               _bfd_generic_get_section_contents
  77 #define bfd_plugin_get_section_contents_in_window     _bfd_generic_get_section_contents_in_window
  78 #define bfd_plugin_bfd_copy_private_header_data       _bfd_generic_bfd_copy_private_header_data
  79 #define bfd_plugin_bfd_merge_private_bfd_data         _bfd_generic_bfd_merge_private_bfd_data
  80 #define bfd_plugin_bfd_copy_private_header_data       _bfd_generic_bfd_copy_private_header_data
  81 #define bfd_plugin_bfd_set_private_flags              _bfd_generic_bfd_set_private_flags
  82 #define bfd_plugin_core_file_matches_executable_p     generic_core_file_matches_executable_p
  83 #define bfd_plugin_bfd_is_local_label_name            _bfd_nosymbols_bfd_is_local_label_name
  84 #define bfd_plugin_bfd_is_target_special_symbol       ((bfd_boolean (*) (bfd *, asymbol *)) bfd_false)
  85 #define bfd_plugin_get_lineno                         _bfd_nosymbols_get_lineno
  86 #define bfd_plugin_find_nearest_line                  _bfd_nosymbols_find_nearest_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_hash_table_free           _bfd_generic_link_hash_table_free
  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_load_plugin (const char *pname)
 162 {
 163   static void *plugin_handle;
 164   int tv_size = 4;
 165   struct ld_plugin_tv tv[tv_size];
 166   int i;
 167   ld_plugin_onload onload;
 168   enum ld_plugin_status status;
 169
 170   plugin_handle = dlopen (pname, RTLD_NOW);
 171   if (!plugin_handle)
 172     {
 173       (*_bfd_error_handler)("%s\n", dlerror ());
 174       return 0;
 175     }
 176
 177   onload = dlsym (plugin_handle, "onload");
 178   if (!onload)
 179     goto err;
 180
 181   i = 0;
 182   tv[i].tv_tag = LDPT_MESSAGE;
 183   tv[i].tv_u.tv_message = message;
 184
 185   ++i;
 186   tv[i].tv_tag = LDPT_REGISTER_CLAIM_FILE_HOOK;
 187   tv[i].tv_u.tv_register_claim_file = register_claim_file;
 188
 189   ++i;
 190   tv[i].tv_tag = LDPT_ADD_SYMBOLS;
 191   tv[i].tv_u.tv_add_symbols = add_symbols;
 192
 193   ++i;
 194   tv[i].tv_tag = LDPT_NULL;
 195   tv[i].tv_u.tv_val = 0;
 196
 197   status = (*onload)(tv);
 198
 199   if (status != LDPS_OK)
 200     goto err;
 201
 202   if (!claim_file)
 203     goto err;
 204
 205   return 1;
 206
 207  err:
 208   plugin_handle = NULL;
 209   return 0;
 210 }
 211
 212 static const char *plugin_name;
 213
 214 void
 215 bfd_plugin_set_plugin (const char *p)
 216 {
 217   plugin_name = p;
 218 }
 219
 220 static int
 221 load_plugin (void)
 222 {
 223   char *plugin_dir;
 224   char *p;
 225   DIR *d;
 226   struct dirent *ent;
 227   int found = 0;
 228
 229   if (plugin_name)
 230     return try_load_plugin (plugin_name);
 231
 232   if (plugin_program_name == NULL)
 233     return 0;
 234
 235   plugin_dir = concat (BINDIR, "/../lib/bfd-plugins", NULL);
 236   p = make_relative_prefix (plugin_program_name,
 237                             BINDIR,
 238                             plugin_dir);
 239   free (plugin_dir);
 240   plugin_dir = NULL;
 241
 242   d = opendir (p);
 243   if (!d)
 244     goto out;
 245
 246   while ((ent = readdir (d)))
 247     {
 248       char *full_name;
 249       struct stat s;
 250
 251       full_name = concat (p, "/", ent->d_name, NULL);
 252       if (stat(full_name, &s) == 0 && S_ISREG (s.st_mode))
 253         found = try_load_plugin (full_name);
 254       free (full_name);
 255       if (found)
 256         break;
 257     }
 258
 259  out:
 260   free (p);
 261   if (d)
 262     closedir (d);
 263
 264   return found;
 265 }
 266
 267
 268 static const bfd_target *
 269 bfd_plugin_object_p (bfd *abfd)
 270 {
 271   int claimed = 0;
 272   struct ld_plugin_input_file file;
 273   bfd *iobfd;
 274   static int have_loaded = 0;
 275   static int have_plugin = 0;
 276
 277   if (!have_loaded)
 278     {
 279       have_loaded = 1;
 280       have_plugin = load_plugin ();
 281     }
 282   if (!have_plugin)
 283     return NULL;
 284
 285   file.name = abfd->filename;
 286
 287   if (abfd->my_archive)
 288     {
 289       iobfd = abfd->my_archive;
 290       file.offset = abfd->origin;
 291       file.filesize = arelt_size (abfd);
 292     }
 293   else
 294     {
 295       iobfd = abfd;
 296       file.offset = 0;
 297       file.filesize = 0;
 298     }
 299
 300   if (!iobfd->iostream && !bfd_open_file (iobfd))
 301     return NULL;
 302
 303   file.fd = fileno ((FILE *) iobfd->iostream);
 304
 305   if (!abfd->my_archive)
 306     {
 307       struct stat stat_buf;
 308       if (fstat (file.fd, &stat_buf))
 309         return NULL;
 310       file.filesize = stat_buf.st_size;
 311     }
 312
 313   file.handle = abfd;
 314   off_t cur_offset = lseek(file.fd, 0, SEEK_CUR);
 315   claim_file (&file, &claimed);
 316   lseek(file.fd, cur_offset, SEEK_SET);
 317   if (!claimed)
 318     return NULL;
 319
 320   return abfd->xvec;
 321 }
 322
 323 /* Copy any private info we understand from the input bfd
 324    to the output bfd.  */
 325
 326 static bfd_boolean
 327 bfd_plugin_bfd_copy_private_bfd_data (bfd *ibfd ATTRIBUTE_UNUSED,
 328                                       bfd *obfd ATTRIBUTE_UNUSED)
 329 {
 330   BFD_ASSERT (0);
 331   return TRUE;
 332 }
 333
 334 /* Copy any private info we understand from the input section
 335    to the output section.  */
 336
 337 static bfd_boolean
 338 bfd_plugin_bfd_copy_private_section_data (bfd *ibfd ATTRIBUTE_UNUSED,
 339                                           asection *isection ATTRIBUTE_UNUSED,
 340                                           bfd *obfd ATTRIBUTE_UNUSED,
 341                                           asection *osection ATTRIBUTE_UNUSED)
 342 {
 343   BFD_ASSERT (0);
 344   return TRUE;
 345 }
 346
 347 /* Copy any private info we understand from the input symbol
 348    to the output symbol.  */
 349
 350 static bfd_boolean
 351 bfd_plugin_bfd_copy_private_symbol_data (bfd *ibfd ATTRIBUTE_UNUSED,
 352                                          asymbol *isymbol ATTRIBUTE_UNUSED,
 353                                          bfd *obfd ATTRIBUTE_UNUSED,
 354                                          asymbol *osymbol ATTRIBUTE_UNUSED)
 355 {
 356   BFD_ASSERT (0);
 357   return TRUE;
 358 }
 359
 360 static bfd_boolean
 361 bfd_plugin_bfd_print_private_bfd_data (bfd *abfd ATTRIBUTE_UNUSED, PTR ptr ATTRIBUTE_UNUSED)
 362 {
 363   BFD_ASSERT (0);
 364   return TRUE;
 365 }
 366
 367 static char *
 368 bfd_plugin_core_file_failing_command (bfd *abfd ATTRIBUTE_UNUSED)
 369 {
 370   BFD_ASSERT (0);
 371   return NULL;
 372 }
 373
 374 static int
 375 bfd_plugin_core_file_failing_signal (bfd *abfd ATTRIBUTE_UNUSED)
 376 {
 377   BFD_ASSERT (0);
 378   return 0;
 379 }
 380
 381 static int
 382 bfd_plugin_core_file_pid (bfd *abfd ATTRIBUTE_UNUSED)
 383 {
 384   BFD_ASSERT (0);
 385   return 0;
 386 }
 387
 388 static long
 389 bfd_plugin_get_symtab_upper_bound (bfd *abfd)
 390 {
 391   struct plugin_data_struct *plugin_data = abfd->tdata.plugin_data;
 392   long nsyms = plugin_data->nsyms;
 393
 394   BFD_ASSERT (nsyms >= 0);
 395
 396   return ((nsyms + 1) * sizeof (asymbol *));
 397 }
 398
 399 static flagword
 400 convert_flags (const struct ld_plugin_symbol *sym)
 401 {
 402  switch (sym->def)
 403    {
 404    case LDPK_DEF:
 405    case LDPK_COMMON:
 406    case LDPK_UNDEF:
 407      return BSF_GLOBAL;
 408
 409    case LDPK_WEAKUNDEF:
 410    case LDPK_WEAKDEF:
 411      return BSF_GLOBAL | BSF_WEAK;
 412
 413    default:
 414      BFD_ASSERT (0);
 415      return 0;
 416    }
 417 }
 418
 419 static long
 420 bfd_plugin_canonicalize_symtab (bfd *abfd,
 421                                 asymbol **alocation)
 422 {
 423   struct plugin_data_struct *plugin_data = abfd->tdata.plugin_data;
 424   long nsyms = plugin_data->nsyms;
 425   const struct ld_plugin_symbol *syms = plugin_data->syms;
 426   static asection fake_section;
 427   static asection fake_common_section;
 428   int i;
 429
 430   fake_section.name = ".text";
 431   fake_common_section.flags = SEC_IS_COMMON;
 432
 433   for (i = 0; i < nsyms; i++)
 434     {
 435       asymbol *s = bfd_alloc (abfd, sizeof (asymbol));
 436
 437       BFD_ASSERT (s);
 438       alocation[i] = s;
 439
 440       s->the_bfd = abfd;
 441       s->name = syms[i].name;
 442       s->value = 0;
 443       s->flags = convert_flags (&syms[i]);
 444       switch (syms[i].def)
 445         {
 446         case LDPK_COMMON:
 447           s->section = &fake_common_section;
 448           break;
 449         case LDPK_UNDEF:
 450         case LDPK_WEAKUNDEF:
 451           s->section = bfd_und_section_ptr;
 452           break;
 453         case LDPK_DEF:
 454         case LDPK_WEAKDEF:
 455           s->section = &fake_section;
 456           break;
 457         default:
 458           BFD_ASSERT (0);
 459         }
 460
 461       s->udata.p = (void *) &syms[i];
 462     }
 463
 464   return nsyms;
 465 }
 466
 467 static void
 468 bfd_plugin_print_symbol (bfd *abfd ATTRIBUTE_UNUSED,
 469                          PTR afile ATTRIBUTE_UNUSED,
 470                          asymbol *symbol ATTRIBUTE_UNUSED,
 471                          bfd_print_symbol_type how ATTRIBUTE_UNUSED)
 472 {
 473   BFD_ASSERT (0);
 474 }
 475
 476 static void
 477 bfd_plugin_get_symbol_info (bfd *abfd ATTRIBUTE_UNUSED,
 478                             asymbol *symbol,
 479                             symbol_info *ret)
 480 {
 481   bfd_symbol_info (symbol, ret);
 482 }
 483
 484 /* Make an empty symbol. */
 485
 486 static asymbol *
 487 bfd_plugin_make_empty_symbol (bfd *abfd)
 488 {
 489   asymbol *new_symbol = bfd_zalloc (abfd, sizeof (asymbol));
 490   if (new_symbol == NULL)
 491     return new_symbol;
 492   new_symbol->the_bfd = abfd;
 493   return new_symbol;
 494 }
 495
 496 static int
 497 bfd_plugin_sizeof_headers (bfd *a ATTRIBUTE_UNUSED,
 498                            struct bfd_link_info *info ATTRIBUTE_UNUSED)
 499 {
 500   BFD_ASSERT (0);
 501   return 0;
 502 }
 503
 504 const bfd_target plugin_vec =
 505 {
 506   "plugin",                     /* Name.  */
 507   bfd_target_unknown_flavour,
 508   BFD_ENDIAN_LITTLE,            /* Target byte order.  */
 509   BFD_ENDIAN_LITTLE,            /* Target headers byte order.  */
 510   (HAS_RELOC | EXEC_P |         /* Object flags.  */
 511    HAS_LINENO | HAS_DEBUG |
 512    HAS_SYMS | HAS_LOCALS | DYNAMIC | WP_TEXT | D_PAGED),
 513   (SEC_CODE | SEC_DATA | SEC_ROM | SEC_HAS_CONTENTS
 514    | SEC_ALLOC | SEC_LOAD | SEC_RELOC), /* Section flags.  */
 515   0,                            /* symbol_leading_char.  */
 516   '/',                          /* ar_pad_char.  */
 517   15,                           /* ar_max_namelen.  */
 518   0,                            /* match priority.  */
 519
 520   bfd_getl64, bfd_getl_signed_64, bfd_putl64,
 521   bfd_getl32, bfd_getl_signed_32, bfd_putl32,
 522   bfd_getl16, bfd_getl_signed_16, bfd_putl16,   /* data */
 523   bfd_getl64, bfd_getl_signed_64, bfd_putl64,
 524   bfd_getl32, bfd_getl_signed_32, bfd_putl32,
 525   bfd_getl16, bfd_getl_signed_16, bfd_putl16,   /* hdrs */
 526
 527   {                             /* bfd_check_format.  */
 528     _bfd_dummy_target,
 529     bfd_plugin_object_p,
 530     bfd_generic_archive_p,
 531     _bfd_dummy_target
 532   },
 533   {                             /* bfd_set_format.  */
 534     bfd_false,
 535     bfd_false,
 536     _bfd_generic_mkarchive,
 537     bfd_false,
 538   },
 539   {                             /* bfd_write_contents.  */
 540     bfd_false,
 541     bfd_false,
 542     _bfd_write_archive_contents,
 543     bfd_false,
 544   },
 545
 546   BFD_JUMP_TABLE_GENERIC (bfd_plugin),
 547   BFD_JUMP_TABLE_COPY (bfd_plugin),
 548   BFD_JUMP_TABLE_CORE (bfd_plugin),
 549   BFD_JUMP_TABLE_ARCHIVE (_bfd_archive_coff),
 550   BFD_JUMP_TABLE_SYMBOLS (bfd_plugin),
 551   BFD_JUMP_TABLE_RELOCS (_bfd_norelocs),
 552   BFD_JUMP_TABLE_WRITE (bfd_plugin),
 553   BFD_JUMP_TABLE_LINK (bfd_plugin),
 554   BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic),
 555
 556   NULL,
 557
 558   NULL                          /* backend_data.  */
 559 };
 560 #endif /* BFD_SUPPORTS_PLUGIN */