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