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