bfd/plugin.c

   1 /* Plugin support for BFD.
   2    Copyright 2009
   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 "config.h"
  23 #include "bfd.h"
  24
  25 #if BFD_SUPPORTS_PLUGINS
  26
  27 #include <assert.h>
  28 #include <dlfcn.h>
  29 #include <stdarg.h>
  30 #include "plugin-api.h"
  31 #include "sysdep.h"
  32 #include "plugin.h"
  33 #include "libbfd.h"
  34 #include "libiberty.h"
  35 #include <dirent.h>
  36
  37 #define bfd_plugin_close_and_cleanup                  _bfd_generic_close_and_cleanup
  38 #define bfd_plugin_bfd_free_cached_info               _bfd_generic_bfd_free_cached_info
  39 #define bfd_plugin_new_section_hook                   _bfd_generic_new_section_hook
  40 #define bfd_plugin_get_section_contents               _bfd_generic_get_section_contents
  41 #define bfd_plugin_get_section_contents_in_window     _bfd_generic_get_section_contents_in_window
  42 #define bfd_plugin_bfd_copy_private_header_data       _bfd_generic_bfd_copy_private_header_data
  43 #define bfd_plugin_bfd_merge_private_bfd_data         _bfd_generic_bfd_merge_private_bfd_data
  44 #define bfd_plugin_bfd_copy_private_header_data       _bfd_generic_bfd_copy_private_header_data
  45 #define bfd_plugin_bfd_set_private_flags              _bfd_generic_bfd_set_private_flags
  46 #define bfd_plugin_core_file_matches_executable_p     generic_core_file_matches_executable_p
  47 #define bfd_plugin_bfd_is_local_label_name            _bfd_nosymbols_bfd_is_local_label_name
  48 #define bfd_plugin_bfd_is_target_special_symbol       ((bfd_boolean (*) (bfd *, asymbol *)) bfd_false)
  49 #define bfd_plugin_get_lineno                         _bfd_nosymbols_get_lineno
  50 #define bfd_plugin_find_nearest_line                  _bfd_nosymbols_find_nearest_line
  51 #define bfd_plugin_find_inliner_info                  _bfd_nosymbols_find_inliner_info
  52 #define bfd_plugin_bfd_make_debug_symbol              _bfd_nosymbols_bfd_make_debug_symbol
  53 #define bfd_plugin_read_minisymbols                   _bfd_generic_read_minisymbols
  54 #define bfd_plugin_minisymbol_to_symbol               _bfd_generic_minisymbol_to_symbol
  55 #define bfd_plugin_set_arch_mach                      bfd_default_set_arch_mach
  56 #define bfd_plugin_set_section_contents               _bfd_generic_set_section_contents
  57 #define bfd_plugin_bfd_get_relocated_section_contents bfd_generic_get_relocated_section_contents
  58 #define bfd_plugin_bfd_relax_section                  bfd_generic_relax_section
  59 #define bfd_plugin_bfd_link_hash_table_create         _bfd_generic_link_hash_table_create
  60 #define bfd_plugin_bfd_link_hash_table_free           _bfd_generic_link_hash_table_free
  61 #define bfd_plugin_bfd_link_add_symbols               _bfd_generic_link_add_symbols
  62 #define bfd_plugin_bfd_link_just_syms                 _bfd_generic_link_just_syms
  63 #define bfd_plugin_bfd_final_link                     _bfd_generic_final_link
  64 #define bfd_plugin_bfd_link_split_section             _bfd_generic_link_split_section
  65 #define bfd_plugin_bfd_gc_sections                    bfd_generic_gc_sections
  66 #define bfd_plugin_bfd_merge_sections                 bfd_generic_merge_sections
  67 #define bfd_plugin_bfd_is_group_section               bfd_generic_is_group_section
  68 #define bfd_plugin_bfd_discard_group                  bfd_generic_discard_group
  69 #define bfd_plugin_section_already_linked             _bfd_generic_section_already_linked
  70 #define bfd_plugin_bfd_define_common_symbol           bfd_generic_define_common_symbol
  71 #define bfd_plugin_bfd_copy_link_hash_symbol_type     _bfd_generic_copy_link_hash_symbol_type
  72
  73 static enum ld_plugin_status
  74 message (int level ATTRIBUTE_UNUSED,
  75          const char * format, ...)
  76 {
  77   va_list args;
  78   va_start (args, format);
  79   printf ("bfd plugin: ");
  80   vprintf (format, args);
  81   va_end (args);
  82   return LDPS_OK;
  83 }
  84
  85 /* Register a claim-file handler. */
  86 static ld_plugin_claim_file_handler claim_file;
  87
  88 static enum ld_plugin_status
  89 register_claim_file (ld_plugin_claim_file_handler handler)
  90 {
  91   claim_file = handler;
  92   return LDPS_OK;
  93 }
  94
  95 static enum ld_plugin_status
  96 add_symbols (void * handle,
  97              int nsyms,
  98              const struct ld_plugin_symbol * syms)
  99 {
 100   bfd *abfd = handle;
 101   struct plugin_data_struct *plugin_data =
 102     bfd_alloc (abfd, sizeof (plugin_data_struct));;
 103
 104   plugin_data->nsyms = nsyms;
 105   plugin_data->syms = syms;
 106
 107   if (nsyms != 0)
 108     abfd->flags |= HAS_SYMS;
 109
 110   abfd->tdata.plugin_data = plugin_data;
 111   return LDPS_OK;
 112 }
 113
 114 static const char *plugin_program_name;
 115
 116 void
 117 bfd_plugin_set_program_name (const char *program_name)
 118 {
 119   plugin_program_name = program_name;
 120 }
 121
 122 static int
 123 try_load_plugin (const char *pname)
 124 {
 125   static void *plugin_handle;
 126   int tv_size = 4;
 127   struct ld_plugin_tv tv[tv_size];
 128   int i;
 129   ld_plugin_onload onload;
 130   enum ld_plugin_status status;
 131
 132   plugin_handle = dlopen (pname, RTLD_NOW);
 133   if (!plugin_handle)
 134     {
 135       (*_bfd_error_handler)("%s\n", dlerror ());
 136       return 0;
 137     }
 138
 139   onload = dlsym (plugin_handle, "onload");
 140   if (!onload)
 141     goto err;
 142
 143   i = 0;
 144   tv[i].tv_tag = LDPT_MESSAGE;
 145   tv[i].tv_u.tv_message = message;
 146
 147   ++i;
 148   tv[i].tv_tag = LDPT_REGISTER_CLAIM_FILE_HOOK;
 149   tv[i].tv_u.tv_register_claim_file = register_claim_file;
 150
 151   ++i;
 152   tv[i].tv_tag = LDPT_ADD_SYMBOLS;
 153   tv[i].tv_u.tv_add_symbols = add_symbols;
 154
 155   ++i;
 156   tv[i].tv_tag = LDPT_NULL;
 157   tv[i].tv_u.tv_val = 0;
 158
 159   status = (*onload)(tv);
 160
 161   if (status != LDPS_OK)
 162     goto err;
 163
 164   if (!claim_file)
 165     goto err;
 166
 167   return 1;
 168
 169  err:
 170   plugin_handle = NULL;
 171   return 0;
 172 }
 173
 174 static const char *plugin_name;
 175
 176 void
 177 bfd_plugin_set_plugin (const char *p)
 178 {
 179   plugin_name = p;
 180 }
 181
 182 static int
 183 load_plugin (void)
 184 {
 185   char *plugin_dir;
 186   char *p;
 187   DIR *d;
 188   struct dirent *ent;
 189   int found = 0;
 190
 191   if (plugin_name)
 192     return try_load_plugin (plugin_name);
 193
 194   if (plugin_program_name == NULL)
 195     return 0;
 196
 197   plugin_dir = concat (BINDIR, "/../lib/bfd-plugins", NULL);
 198   p = make_relative_prefix (plugin_program_name,
 199                             BINDIR,
 200                             plugin_dir);
 201   free (plugin_dir);
 202   plugin_dir = NULL;
 203
 204   d = opendir (p);
 205   if (!d)
 206     goto out;
 207
 208   while ((ent = readdir (d)))
 209     {
 210       char *full_name;
 211       struct stat s;
 212
 213       full_name = concat (p, "/", ent->d_name, NULL);
 214       if (stat(full_name, &s) == 0 && S_ISREG (s.st_mode))
 215         found = try_load_plugin (full_name);
 216       free (full_name);
 217       if (found)
 218         break;
 219     }
 220
 221  out:
 222   free (p);
 223   if (d)
 224     closedir (d);
 225
 226   return found;
 227 }
 228
 229
 230 static const bfd_target *
 231 bfd_plugin_object_p (bfd *abfd)
 232 {
 233   int claimed = 0;
 234   int t = load_plugin ();
 235   struct ld_plugin_input_file file;
 236   bfd *iobfd;
 237
 238   if (!t)
 239     return NULL;
 240
 241   file.name = abfd->filename;
 242
 243   if (abfd->my_archive)
 244     {
 245       iobfd = abfd->my_archive;
 246       file.offset = abfd->origin;
 247       file.filesize = arelt_size (abfd);
 248     }
 249   else
 250     {
 251       iobfd = abfd;
 252       file.offset = 0;
 253       file.filesize = 0; /*FIXME*/
 254     }
 255
 256   if (!iobfd->iostream && !bfd_open_file (iobfd))
 257     return NULL;
 258
 259   file.fd = fileno ((FILE *) iobfd->iostream);
 260
 261   file.handle = abfd;
 262   claim_file (&file, &claimed);
 263   if (!claimed)
 264     return NULL;
 265
 266   return abfd->xvec;
 267 }
 268
 269 /* Copy any private info we understand from the input bfd
 270    to the output bfd.  */
 271
 272 static bfd_boolean
 273 bfd_plugin_bfd_copy_private_bfd_data (bfd *ibfd ATTRIBUTE_UNUSED,
 274                                       bfd *obfd ATTRIBUTE_UNUSED)
 275 {
 276   BFD_ASSERT (0);
 277   return TRUE;
 278 }
 279
 280 /* Copy any private info we understand from the input section
 281    to the output section.  */
 282
 283 static bfd_boolean
 284 bfd_plugin_bfd_copy_private_section_data (bfd *ibfd ATTRIBUTE_UNUSED,
 285                                           asection *isection ATTRIBUTE_UNUSED,
 286                                           bfd *obfd ATTRIBUTE_UNUSED,
 287                                           asection *osection ATTRIBUTE_UNUSED)
 288 {
 289   BFD_ASSERT (0);
 290   return TRUE;
 291 }
 292
 293 /* Copy any private info we understand from the input symbol
 294    to the output symbol.  */
 295
 296 static bfd_boolean
 297 bfd_plugin_bfd_copy_private_symbol_data (bfd *ibfd ATTRIBUTE_UNUSED,
 298                                          asymbol *isymbol ATTRIBUTE_UNUSED,
 299                                          bfd *obfd ATTRIBUTE_UNUSED,
 300                                          asymbol *osymbol ATTRIBUTE_UNUSED)
 301 {
 302   BFD_ASSERT (0);
 303   return TRUE;
 304 }
 305
 306 static bfd_boolean
 307 bfd_plugin_bfd_print_private_bfd_data (bfd *abfd ATTRIBUTE_UNUSED, PTR ptr ATTRIBUTE_UNUSED)
 308 {
 309   BFD_ASSERT (0);
 310   return TRUE;
 311 }
 312
 313 static char *
 314 bfd_plugin_core_file_failing_command (bfd *abfd ATTRIBUTE_UNUSED)
 315 {
 316   BFD_ASSERT (0);
 317   return NULL;
 318 }
 319
 320 static int
 321 bfd_plugin_core_file_failing_signal (bfd *abfd ATTRIBUTE_UNUSED)
 322 {
 323   BFD_ASSERT (0);
 324   return 0;
 325 }
 326
 327 static int
 328 bfd_plugin_core_file_pid (bfd *abfd ATTRIBUTE_UNUSED)
 329 {
 330   BFD_ASSERT (0);
 331   return 0;
 332 }
 333
 334 static long
 335 bfd_plugin_get_symtab_upper_bound (bfd *abfd)
 336 {
 337   struct plugin_data_struct *plugin_data = abfd->tdata.plugin_data;
 338   long nsyms = plugin_data->nsyms;
 339
 340   BFD_ASSERT (nsyms >= 0);
 341
 342   return ((nsyms + 1) * sizeof (asymbol *));
 343 }
 344
 345 static flagword
 346 convert_flags (const struct ld_plugin_symbol *sym)
 347 {
 348  switch (sym->def)
 349    {
 350    case LDPK_DEF:
 351    case LDPK_COMMON:
 352    case LDPK_UNDEF:
 353      return BSF_GLOBAL;
 354
 355    case LDPK_WEAKUNDEF:
 356    case LDPK_WEAKDEF:
 357      return BSF_GLOBAL | BSF_WEAK;
 358
 359    default:
 360      BFD_ASSERT (0);
 361      return 0;
 362    }
 363 }
 364
 365 static long
 366 bfd_plugin_canonicalize_symtab (bfd *abfd,
 367                                 asymbol **alocation)
 368 {
 369   struct plugin_data_struct *plugin_data = abfd->tdata.plugin_data;
 370   long nsyms = plugin_data->nsyms;
 371   const struct ld_plugin_symbol *syms = plugin_data->syms;
 372   static asection fake_section;
 373   static asection fake_common_section;
 374   int i;
 375
 376   fake_section.name = ".text";
 377   fake_common_section.flags = SEC_IS_COMMON;
 378
 379   for (i = 0; i < nsyms; i++)
 380     {
 381       asymbol *s = bfd_alloc (abfd, sizeof (asymbol));
 382
 383       BFD_ASSERT (s);
 384       alocation[i] = s;
 385
 386       s->the_bfd = abfd;
 387       s->name = syms[i].name;
 388       s->value = 0;
 389       s->flags = convert_flags (&syms[i]);
 390       switch (syms[i].def)
 391         {
 392         case LDPK_COMMON:
 393           s->section = &fake_common_section;
 394           break;
 395         case LDPK_UNDEF:
 396         case LDPK_WEAKUNDEF:
 397           s->section = bfd_und_section_ptr;
 398           break;
 399         case LDPK_DEF:
 400         case LDPK_WEAKDEF:
 401           s->section = &fake_section;
 402           break;
 403         default:
 404           BFD_ASSERT (0);
 405         }
 406
 407       s->udata.p = (void *) &syms[i];
 408     }
 409
 410   return nsyms;
 411 }
 412
 413 static void
 414 bfd_plugin_print_symbol (bfd *abfd ATTRIBUTE_UNUSED,
 415                          PTR afile ATTRIBUTE_UNUSED,
 416                          asymbol *symbol ATTRIBUTE_UNUSED,
 417                          bfd_print_symbol_type how ATTRIBUTE_UNUSED)
 418 {
 419   BFD_ASSERT (0);
 420 }
 421
 422 static void
 423 bfd_plugin_get_symbol_info (bfd *abfd ATTRIBUTE_UNUSED,
 424                             asymbol *symbol,
 425                             symbol_info *ret)
 426 {
 427   bfd_symbol_info (symbol, ret);
 428 }
 429
 430 /* Make an empty symbol. */
 431
 432 static asymbol *
 433 bfd_plugin_make_empty_symbol (bfd *abfd)
 434 {
 435   asymbol *new_symbol = bfd_zalloc (abfd, sizeof (asymbol));
 436   if (new_symbol == NULL)
 437     return new_symbol;
 438   new_symbol->the_bfd = abfd;
 439   return new_symbol;
 440 }
 441
 442 static int
 443 bfd_plugin_sizeof_headers (bfd *a ATTRIBUTE_UNUSED,
 444                            struct bfd_link_info *info ATTRIBUTE_UNUSED)
 445 {
 446   BFD_ASSERT (0);
 447   return 0;
 448 }
 449
 450 static bfd_boolean
 451 bfd_plugin_mkobject (bfd *abfd ATTRIBUTE_UNUSED)
 452 {
 453   BFD_ASSERT (0);
 454   return 0;
 455 }
 456
 457 const bfd_target plugin_vec =
 458 {
 459   "plugin",                     /* Name.  */
 460   bfd_target_unknown_flavour,
 461   BFD_ENDIAN_LITTLE,            /* Target byte order.  */
 462   BFD_ENDIAN_LITTLE,            /* Target headers byte order.  */
 463   (HAS_RELOC | EXEC_P |         /* Object flags.  */
 464    HAS_LINENO | HAS_DEBUG |
 465    HAS_SYMS | HAS_LOCALS | DYNAMIC | WP_TEXT | D_PAGED),
 466   (SEC_CODE | SEC_DATA | SEC_ROM | SEC_HAS_CONTENTS
 467    | SEC_ALLOC | SEC_LOAD | SEC_RELOC), /* Section flags.  */
 468   0,                            /* symbol_leading_char.  */
 469   '/',                          /* ar_pad_char.  */
 470   15,                           /* ar_max_namelen.  */
 471
 472   bfd_getl64, bfd_getl_signed_64, bfd_putl64,
 473   bfd_getl32, bfd_getl_signed_32, bfd_putl32,
 474   bfd_getl16, bfd_getl_signed_16, bfd_putl16,   /* data */
 475   bfd_getl64, bfd_getl_signed_64, bfd_putl64,
 476   bfd_getl32, bfd_getl_signed_32, bfd_putl32,
 477   bfd_getl16, bfd_getl_signed_16, bfd_putl16,   /* hdrs */
 478
 479   {                             /* bfd_check_format.  */
 480     _bfd_dummy_target,
 481     bfd_plugin_object_p,
 482     bfd_generic_archive_p,
 483     _bfd_dummy_target
 484   },
 485   {                             /* bfd_set_format.  */
 486     bfd_false,
 487     bfd_plugin_mkobject,
 488     _bfd_generic_mkarchive,
 489     bfd_false,
 490   },
 491   {                             /* bfd_write_contents.  */
 492     bfd_false,
 493     bfd_false,
 494     _bfd_write_archive_contents,
 495     bfd_false,
 496   },
 497
 498   BFD_JUMP_TABLE_GENERIC (bfd_plugin),
 499   BFD_JUMP_TABLE_COPY (bfd_plugin),
 500   BFD_JUMP_TABLE_CORE (bfd_plugin),
 501   BFD_JUMP_TABLE_ARCHIVE (_bfd_archive_coff),
 502   BFD_JUMP_TABLE_SYMBOLS (bfd_plugin),
 503   BFD_JUMP_TABLE_RELOCS (_bfd_norelocs),
 504   BFD_JUMP_TABLE_WRITE (bfd_plugin),
 505   BFD_JUMP_TABLE_LINK (bfd_plugin),
 506   BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic),
 507
 508   NULL,
 509
 510   NULL                          /* backend_data.  */
 511 };
 512 #endif /* BFD_SUPPORTS_PLUGIN */