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   if (!t)
 237     return NULL;
 238
 239   file.name = abfd->filename;
 240
 241   if (abfd->iostream)
 242     {
 243       file.fd = fileno ((FILE *) abfd->iostream);
 244       file.offset = 0;
 245       file.filesize = 0; /*FIXME*/
 246     }
 247   else
 248     {
 249       bfd *archive = abfd->my_archive;
 250       BFD_ASSERT (archive);
 251       file.fd = fileno ((FILE *) archive->iostream);
 252       file.offset = abfd->origin;
 253       file.filesize = arelt_size (abfd);
 254
 255     }
 256   file.handle = abfd;
 257   claim_file (&file, &claimed);
 258   if (!claimed)
 259     return NULL;
 260
 261   return abfd->xvec;
 262 }
 263
 264 /* Copy any private info we understand from the input bfd
 265    to the output bfd.  */
 266
 267 static bfd_boolean
 268 bfd_plugin_bfd_copy_private_bfd_data (bfd *ibfd ATTRIBUTE_UNUSED,
 269                                       bfd *obfd ATTRIBUTE_UNUSED)
 270 {
 271   BFD_ASSERT (0);
 272   return TRUE;
 273 }
 274
 275 /* Copy any private info we understand from the input section
 276    to the output section.  */
 277
 278 static bfd_boolean
 279 bfd_plugin_bfd_copy_private_section_data (bfd *ibfd ATTRIBUTE_UNUSED,
 280                                           asection *isection ATTRIBUTE_UNUSED,
 281                                           bfd *obfd ATTRIBUTE_UNUSED,
 282                                           asection *osection ATTRIBUTE_UNUSED)
 283 {
 284   BFD_ASSERT (0);
 285   return TRUE;
 286 }
 287
 288 /* Copy any private info we understand from the input symbol
 289    to the output symbol.  */
 290
 291 static bfd_boolean
 292 bfd_plugin_bfd_copy_private_symbol_data (bfd *ibfd ATTRIBUTE_UNUSED,
 293                                          asymbol *isymbol ATTRIBUTE_UNUSED,
 294                                          bfd *obfd ATTRIBUTE_UNUSED,
 295                                          asymbol *osymbol ATTRIBUTE_UNUSED)
 296 {
 297   BFD_ASSERT (0);
 298   return TRUE;
 299 }
 300
 301 static bfd_boolean
 302 bfd_plugin_bfd_print_private_bfd_data (bfd *abfd ATTRIBUTE_UNUSED, PTR ptr ATTRIBUTE_UNUSED)
 303 {
 304   BFD_ASSERT (0);
 305   return TRUE;
 306 }
 307
 308 static char *
 309 bfd_plugin_core_file_failing_command (bfd *abfd ATTRIBUTE_UNUSED)
 310 {
 311   BFD_ASSERT (0);
 312   return NULL;
 313 }
 314
 315 static int
 316 bfd_plugin_core_file_failing_signal (bfd *abfd ATTRIBUTE_UNUSED)
 317 {
 318   BFD_ASSERT (0);
 319   return 0;
 320 }
 321
 322 static long
 323 bfd_plugin_get_symtab_upper_bound (bfd *abfd)
 324 {
 325   struct plugin_data_struct *plugin_data = abfd->tdata.plugin_data;
 326   long nsyms = plugin_data->nsyms;
 327
 328   BFD_ASSERT (nsyms >= 0);
 329
 330   return ((nsyms + 1) * sizeof (asymbol *));
 331 }
 332
 333 static flagword
 334 convert_flags (const struct ld_plugin_symbol *sym)
 335 {
 336  switch (sym->def)
 337    {
 338    case LDPK_DEF:
 339    case LDPK_COMMON:
 340    case LDPK_UNDEF:
 341      return BSF_GLOBAL;
 342
 343    case LDPK_WEAKUNDEF:
 344    case LDPK_WEAKDEF:
 345      return BSF_GLOBAL | BSF_WEAK;
 346
 347    default:
 348      BFD_ASSERT (0);
 349      return 0;
 350    }
 351 }
 352
 353 static long
 354 bfd_plugin_canonicalize_symtab (bfd *abfd,
 355                                 asymbol **alocation)
 356 {
 357   struct plugin_data_struct *plugin_data = abfd->tdata.plugin_data;
 358   long nsyms = plugin_data->nsyms;
 359   const struct ld_plugin_symbol *syms = plugin_data->syms;
 360   static asection fake_section;
 361   static asection fake_common_section;
 362   int i;
 363
 364   fake_section.name = ".text";
 365   fake_common_section.flags = SEC_IS_COMMON;
 366
 367   for (i = 0; i < nsyms; i++)
 368     {
 369       asymbol *s = bfd_alloc (abfd, sizeof (asymbol));
 370
 371       BFD_ASSERT (s);
 372       alocation[i] = s;
 373
 374       s->the_bfd = abfd;
 375       s->name = syms[i].name;
 376       s->value = 0;
 377       s->flags = convert_flags (&syms[i]);
 378       switch (syms[i].def)
 379         {
 380         case LDPK_COMMON:
 381           s->section = &fake_common_section;
 382           break;
 383         case LDPK_UNDEF:
 384         case LDPK_WEAKUNDEF:
 385           s->section = bfd_und_section_ptr;
 386           break;
 387         case LDPK_DEF:
 388         case LDPK_WEAKDEF:
 389           s->section = &fake_section;
 390           break;
 391         default:
 392           BFD_ASSERT (0);
 393         }
 394
 395       s->udata.p = (void *) &syms[i];
 396     }
 397
 398   return nsyms;
 399 }
 400
 401 static void
 402 bfd_plugin_print_symbol (bfd *abfd ATTRIBUTE_UNUSED,
 403                          PTR afile ATTRIBUTE_UNUSED,
 404                          asymbol *symbol ATTRIBUTE_UNUSED,
 405                          bfd_print_symbol_type how ATTRIBUTE_UNUSED)
 406 {
 407   BFD_ASSERT (0);
 408 }
 409
 410 static void
 411 bfd_plugin_get_symbol_info (bfd *abfd ATTRIBUTE_UNUSED,
 412                             asymbol *symbol,
 413                             symbol_info *ret)
 414 {
 415   bfd_symbol_info (symbol, ret);
 416 }
 417
 418 /* Make an empty symbol. */
 419
 420 static asymbol *
 421 bfd_plugin_make_empty_symbol (bfd *abfd)
 422 {
 423   asymbol *new_symbol = bfd_zalloc (abfd, sizeof (asymbol));
 424   if (new_symbol == NULL)
 425     return new_symbol;
 426   new_symbol->the_bfd = abfd;
 427   return new_symbol;
 428 }
 429
 430 static int
 431 bfd_plugin_sizeof_headers (bfd *a ATTRIBUTE_UNUSED,
 432                            struct bfd_link_info *info ATTRIBUTE_UNUSED)
 433 {
 434   BFD_ASSERT (0);
 435   return 0;
 436 }
 437
 438 static bfd_boolean
 439 bfd_plugin_mkobject (bfd *abfd ATTRIBUTE_UNUSED)
 440 {
 441   BFD_ASSERT (0);
 442   return 0;
 443 }
 444
 445 const bfd_target plugin_vec =
 446 {
 447   "plugin",                     /* Name.  */
 448   bfd_target_unknown_flavour,
 449   BFD_ENDIAN_LITTLE,            /* Target byte order.  */
 450   BFD_ENDIAN_LITTLE,            /* Target headers byte order.  */
 451   (HAS_RELOC | EXEC_P |         /* Object flags.  */
 452    HAS_LINENO | HAS_DEBUG |
 453    HAS_SYMS | HAS_LOCALS | DYNAMIC | WP_TEXT | D_PAGED),
 454   (SEC_CODE | SEC_DATA | SEC_ROM | SEC_HAS_CONTENTS
 455    | SEC_ALLOC | SEC_LOAD | SEC_RELOC), /* Section flags.  */
 456   0,                            /* symbol_leading_char.  */
 457   '/',                          /* ar_pad_char.  */
 458   15,                           /* ar_max_namelen.  */
 459
 460   bfd_getl64, bfd_getl_signed_64, bfd_putl64,
 461   bfd_getl32, bfd_getl_signed_32, bfd_putl32,
 462   bfd_getl16, bfd_getl_signed_16, bfd_putl16,   /* data */
 463   bfd_getl64, bfd_getl_signed_64, bfd_putl64,
 464   bfd_getl32, bfd_getl_signed_32, bfd_putl32,
 465   bfd_getl16, bfd_getl_signed_16, bfd_putl16,   /* hdrs */
 466
 467   {                             /* bfd_check_format.  */
 468     _bfd_dummy_target,
 469     bfd_plugin_object_p,
 470     bfd_generic_archive_p,
 471     _bfd_dummy_target
 472   },
 473   {                             /* bfd_set_format.  */
 474     bfd_false,
 475     bfd_plugin_mkobject,
 476     _bfd_generic_mkarchive,
 477     bfd_false,
 478   },
 479   {                             /* bfd_write_contents.  */
 480     bfd_false,
 481     bfd_false,
 482     _bfd_write_archive_contents,
 483     bfd_false,
 484   },
 485
 486   BFD_JUMP_TABLE_GENERIC (bfd_plugin),
 487   BFD_JUMP_TABLE_COPY (bfd_plugin),
 488   BFD_JUMP_TABLE_CORE (bfd_plugin),
 489   BFD_JUMP_TABLE_ARCHIVE (_bfd_archive_coff),
 490   BFD_JUMP_TABLE_SYMBOLS (bfd_plugin),
 491   BFD_JUMP_TABLE_RELOCS (_bfd_norelocs),
 492   BFD_JUMP_TABLE_WRITE (bfd_plugin),
 493   BFD_JUMP_TABLE_LINK (bfd_plugin),
 494   BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic),
 495
 496   NULL,
 497
 498   NULL                          /* backend_data.  */
 499 };
 500 #endif /* BFD_SUPPORTS_PLUGIN */