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