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