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   struct ld_plugin_input_file file;
 236   bfd *iobfd;
 237   static int have_loaded = 0;
 238   static int have_plugin = 0;
 239
 240   if (!have_loaded)
 241     {
 242       have_loaded = 1;
 243       have_plugin = load_plugin ();
 244     }
 245   if (!have_plugin)
 246     return NULL;
 247
 248   file.name = abfd->filename;
 249
 250   if (abfd->my_archive)
 251     {
 252       iobfd = abfd->my_archive;
 253       file.offset = abfd->origin;
 254       file.filesize = arelt_size (abfd);
 255     }
 256   else
 257     {
 258       iobfd = abfd;
 259       file.offset = 0;
 260       file.filesize = 0;
 261     }
 262
 263   if (!iobfd->iostream && !bfd_open_file (iobfd))
 264     return NULL;
 265
 266   file.fd = fileno ((FILE *) iobfd->iostream);
 267
 268   if (!abfd->my_archive)
 269     {
 270       struct stat stat_buf;
 271       if (fstat (file.fd, &stat_buf))
 272         return NULL;
 273       file.filesize = stat_buf.st_size;
 274     }
 275
 276   file.handle = abfd;
 277   off_t cur_offset = lseek(file.fd, 0, SEEK_CUR);
 278   claim_file (&file, &claimed);
 279   lseek(file.fd, cur_offset, SEEK_SET);
 280   if (!claimed)
 281     return NULL;
 282
 283   return abfd->xvec;
 284 }
 285
 286 /* Copy any private info we understand from the input bfd
 287    to the output bfd.  */
 288
 289 static bfd_boolean
 290 bfd_plugin_bfd_copy_private_bfd_data (bfd *ibfd ATTRIBUTE_UNUSED,
 291                                       bfd *obfd ATTRIBUTE_UNUSED)
 292 {
 293   BFD_ASSERT (0);
 294   return TRUE;
 295 }
 296
 297 /* Copy any private info we understand from the input section
 298    to the output section.  */
 299
 300 static bfd_boolean
 301 bfd_plugin_bfd_copy_private_section_data (bfd *ibfd ATTRIBUTE_UNUSED,
 302                                           asection *isection ATTRIBUTE_UNUSED,
 303                                           bfd *obfd ATTRIBUTE_UNUSED,
 304                                           asection *osection ATTRIBUTE_UNUSED)
 305 {
 306   BFD_ASSERT (0);
 307   return TRUE;
 308 }
 309
 310 /* Copy any private info we understand from the input symbol
 311    to the output symbol.  */
 312
 313 static bfd_boolean
 314 bfd_plugin_bfd_copy_private_symbol_data (bfd *ibfd ATTRIBUTE_UNUSED,
 315                                          asymbol *isymbol ATTRIBUTE_UNUSED,
 316                                          bfd *obfd ATTRIBUTE_UNUSED,
 317                                          asymbol *osymbol ATTRIBUTE_UNUSED)
 318 {
 319   BFD_ASSERT (0);
 320   return TRUE;
 321 }
 322
 323 static bfd_boolean
 324 bfd_plugin_bfd_print_private_bfd_data (bfd *abfd ATTRIBUTE_UNUSED, PTR ptr ATTRIBUTE_UNUSED)
 325 {
 326   BFD_ASSERT (0);
 327   return TRUE;
 328 }
 329
 330 static char *
 331 bfd_plugin_core_file_failing_command (bfd *abfd ATTRIBUTE_UNUSED)
 332 {
 333   BFD_ASSERT (0);
 334   return NULL;
 335 }
 336
 337 static int
 338 bfd_plugin_core_file_failing_signal (bfd *abfd ATTRIBUTE_UNUSED)
 339 {
 340   BFD_ASSERT (0);
 341   return 0;
 342 }
 343
 344 static int
 345 bfd_plugin_core_file_pid (bfd *abfd ATTRIBUTE_UNUSED)
 346 {
 347   BFD_ASSERT (0);
 348   return 0;
 349 }
 350
 351 static long
 352 bfd_plugin_get_symtab_upper_bound (bfd *abfd)
 353 {
 354   struct plugin_data_struct *plugin_data = abfd->tdata.plugin_data;
 355   long nsyms = plugin_data->nsyms;
 356
 357   BFD_ASSERT (nsyms >= 0);
 358
 359   return ((nsyms + 1) * sizeof (asymbol *));
 360 }
 361
 362 static flagword
 363 convert_flags (const struct ld_plugin_symbol *sym)
 364 {
 365  switch (sym->def)
 366    {
 367    case LDPK_DEF:
 368    case LDPK_COMMON:
 369    case LDPK_UNDEF:
 370      return BSF_GLOBAL;
 371
 372    case LDPK_WEAKUNDEF:
 373    case LDPK_WEAKDEF:
 374      return BSF_GLOBAL | BSF_WEAK;
 375
 376    default:
 377      BFD_ASSERT (0);
 378      return 0;
 379    }
 380 }
 381
 382 static long
 383 bfd_plugin_canonicalize_symtab (bfd *abfd,
 384                                 asymbol **alocation)
 385 {
 386   struct plugin_data_struct *plugin_data = abfd->tdata.plugin_data;
 387   long nsyms = plugin_data->nsyms;
 388   const struct ld_plugin_symbol *syms = plugin_data->syms;
 389   static asection fake_section;
 390   static asection fake_common_section;
 391   int i;
 392
 393   fake_section.name = ".text";
 394   fake_common_section.flags = SEC_IS_COMMON;
 395
 396   for (i = 0; i < nsyms; i++)
 397     {
 398       asymbol *s = bfd_alloc (abfd, sizeof (asymbol));
 399
 400       BFD_ASSERT (s);
 401       alocation[i] = s;
 402
 403       s->the_bfd = abfd;
 404       s->name = syms[i].name;
 405       s->value = 0;
 406       s->flags = convert_flags (&syms[i]);
 407       switch (syms[i].def)
 408         {
 409         case LDPK_COMMON:
 410           s->section = &fake_common_section;
 411           break;
 412         case LDPK_UNDEF:
 413         case LDPK_WEAKUNDEF:
 414           s->section = bfd_und_section_ptr;
 415           break;
 416         case LDPK_DEF:
 417         case LDPK_WEAKDEF:
 418           s->section = &fake_section;
 419           break;
 420         default:
 421           BFD_ASSERT (0);
 422         }
 423
 424       s->udata.p = (void *) &syms[i];
 425     }
 426
 427   return nsyms;
 428 }
 429
 430 static void
 431 bfd_plugin_print_symbol (bfd *abfd ATTRIBUTE_UNUSED,
 432                          PTR afile ATTRIBUTE_UNUSED,
 433                          asymbol *symbol ATTRIBUTE_UNUSED,
 434                          bfd_print_symbol_type how ATTRIBUTE_UNUSED)
 435 {
 436   BFD_ASSERT (0);
 437 }
 438
 439 static void
 440 bfd_plugin_get_symbol_info (bfd *abfd ATTRIBUTE_UNUSED,
 441                             asymbol *symbol,
 442                             symbol_info *ret)
 443 {
 444   bfd_symbol_info (symbol, ret);
 445 }
 446
 447 /* Make an empty symbol. */
 448
 449 static asymbol *
 450 bfd_plugin_make_empty_symbol (bfd *abfd)
 451 {
 452   asymbol *new_symbol = bfd_zalloc (abfd, sizeof (asymbol));
 453   if (new_symbol == NULL)
 454     return new_symbol;
 455   new_symbol->the_bfd = abfd;
 456   return new_symbol;
 457 }
 458
 459 static int
 460 bfd_plugin_sizeof_headers (bfd *a ATTRIBUTE_UNUSED,
 461                            struct bfd_link_info *info ATTRIBUTE_UNUSED)
 462 {
 463   BFD_ASSERT (0);
 464   return 0;
 465 }
 466
 467 const bfd_target plugin_vec =
 468 {
 469   "plugin",                     /* Name.  */
 470   bfd_target_unknown_flavour,
 471   BFD_ENDIAN_LITTLE,            /* Target byte order.  */
 472   BFD_ENDIAN_LITTLE,            /* Target headers byte order.  */
 473   (HAS_RELOC | EXEC_P |         /* Object flags.  */
 474    HAS_LINENO | HAS_DEBUG |
 475    HAS_SYMS | HAS_LOCALS | DYNAMIC | WP_TEXT | D_PAGED),
 476   (SEC_CODE | SEC_DATA | SEC_ROM | SEC_HAS_CONTENTS
 477    | SEC_ALLOC | SEC_LOAD | SEC_RELOC), /* Section flags.  */
 478   0,                            /* symbol_leading_char.  */
 479   '/',                          /* ar_pad_char.  */
 480   15,                           /* ar_max_namelen.  */
 481
 482   bfd_getl64, bfd_getl_signed_64, bfd_putl64,
 483   bfd_getl32, bfd_getl_signed_32, bfd_putl32,
 484   bfd_getl16, bfd_getl_signed_16, bfd_putl16,   /* data */
 485   bfd_getl64, bfd_getl_signed_64, bfd_putl64,
 486   bfd_getl32, bfd_getl_signed_32, bfd_putl32,
 487   bfd_getl16, bfd_getl_signed_16, bfd_putl16,   /* hdrs */
 488
 489   {                             /* bfd_check_format.  */
 490     _bfd_dummy_target,
 491     bfd_plugin_object_p,
 492     bfd_generic_archive_p,
 493     _bfd_dummy_target
 494   },
 495   {                             /* bfd_set_format.  */
 496     bfd_false,
 497     bfd_false,
 498     _bfd_generic_mkarchive,
 499     bfd_false,
 500   },
 501   {                             /* bfd_write_contents.  */
 502     bfd_false,
 503     bfd_false,
 504     _bfd_write_archive_contents,
 505     bfd_false,
 506   },
 507
 508   BFD_JUMP_TABLE_GENERIC (bfd_plugin),
 509   BFD_JUMP_TABLE_COPY (bfd_plugin),
 510   BFD_JUMP_TABLE_CORE (bfd_plugin),
 511   BFD_JUMP_TABLE_ARCHIVE (_bfd_archive_coff),
 512   BFD_JUMP_TABLE_SYMBOLS (bfd_plugin),
 513   BFD_JUMP_TABLE_RELOCS (_bfd_norelocs),
 514   BFD_JUMP_TABLE_WRITE (bfd_plugin),
 515   BFD_JUMP_TABLE_LINK (bfd_plugin),
 516   BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic),
 517
 518   NULL,
 519
 520   NULL                          /* backend_data.  */
 521 };
 522 #endif /* BFD_SUPPORTS_PLUGIN */