bfd/plugin.c

   1 /* Plugin support for BFD.
   2    Copyright 2009, 2010, 2011
   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_lookup_section_flags           bfd_generic_lookup_section_flags
  67 #define bfd_plugin_bfd_merge_sections                 bfd_generic_merge_sections
  68 #define bfd_plugin_bfd_is_group_section               bfd_generic_is_group_section
  69 #define bfd_plugin_bfd_discard_group                  bfd_generic_discard_group
  70 #define bfd_plugin_section_already_linked             _bfd_generic_section_already_linked
  71 #define bfd_plugin_bfd_define_common_symbol           bfd_generic_define_common_symbol
  72 #define bfd_plugin_bfd_copy_link_hash_symbol_type     _bfd_generic_copy_link_hash_symbol_type
  73
  74 static enum ld_plugin_status
  75 message (int level ATTRIBUTE_UNUSED,
  76          const char * format, ...)
  77 {
  78   va_list args;
  79   va_start (args, format);
  80   printf ("bfd plugin: ");
  81   vprintf (format, args);
  82   putchar ('\n');
  83   va_end (args);
  84   return LDPS_OK;
  85 }
  86
  87 /* Register a claim-file handler. */
  88 static ld_plugin_claim_file_handler claim_file;
  89
  90 static enum ld_plugin_status
  91 register_claim_file (ld_plugin_claim_file_handler handler)
  92 {
  93   claim_file = handler;
  94   return LDPS_OK;
  95 }
  96
  97 static enum ld_plugin_status
  98 add_symbols (void * handle,
  99              int nsyms,
 100              const struct ld_plugin_symbol * syms)
 101 {
 102   bfd *abfd = handle;
 103   struct plugin_data_struct *plugin_data =
 104     bfd_alloc (abfd, sizeof (plugin_data_struct));;
 105
 106   plugin_data->nsyms = nsyms;
 107   plugin_data->syms = syms;
 108
 109   if (nsyms != 0)
 110     abfd->flags |= HAS_SYMS;
 111
 112   abfd->tdata.plugin_data = plugin_data;
 113   return LDPS_OK;
 114 }
 115
 116 static const char *plugin_program_name;
 117
 118 void
 119 bfd_plugin_set_program_name (const char *program_name)
 120 {
 121   plugin_program_name = program_name;
 122 }
 123
 124 static int
 125 try_load_plugin (const char *pname)
 126 {
 127   static void *plugin_handle;
 128   int tv_size = 4;
 129   struct ld_plugin_tv tv[tv_size];
 130   int i;
 131   ld_plugin_onload onload;
 132   enum ld_plugin_status status;
 133
 134   plugin_handle = dlopen (pname, RTLD_NOW);
 135   if (!plugin_handle)
 136     {
 137       (*_bfd_error_handler)("%s\n", dlerror ());
 138       return 0;
 139     }
 140
 141   onload = dlsym (plugin_handle, "onload");
 142   if (!onload)
 143     goto err;
 144
 145   i = 0;
 146   tv[i].tv_tag = LDPT_MESSAGE;
 147   tv[i].tv_u.tv_message = message;
 148
 149   ++i;
 150   tv[i].tv_tag = LDPT_REGISTER_CLAIM_FILE_HOOK;
 151   tv[i].tv_u.tv_register_claim_file = register_claim_file;
 152
 153   ++i;
 154   tv[i].tv_tag = LDPT_ADD_SYMBOLS;
 155   tv[i].tv_u.tv_add_symbols = add_symbols;
 156
 157   ++i;
 158   tv[i].tv_tag = LDPT_NULL;
 159   tv[i].tv_u.tv_val = 0;
 160
 161   status = (*onload)(tv);
 162
 163   if (status != LDPS_OK)
 164     goto err;
 165
 166   if (!claim_file)
 167     goto err;
 168
 169   return 1;
 170
 171  err:
 172   plugin_handle = NULL;
 173   return 0;
 174 }
 175
 176 static const char *plugin_name;
 177
 178 void
 179 bfd_plugin_set_plugin (const char *p)
 180 {
 181   plugin_name = p;
 182 }
 183
 184 static int
 185 load_plugin (void)
 186 {
 187   char *plugin_dir;
 188   char *p;
 189   DIR *d;
 190   struct dirent *ent;
 191   int found = 0;
 192
 193   if (plugin_name)
 194     return try_load_plugin (plugin_name);
 195
 196   if (plugin_program_name == NULL)
 197     return 0;
 198
 199   plugin_dir = concat (BINDIR, "/../lib/bfd-plugins", NULL);
 200   p = make_relative_prefix (plugin_program_name,
 201                             BINDIR,
 202                             plugin_dir);
 203   free (plugin_dir);
 204   plugin_dir = NULL;
 205
 206   d = opendir (p);
 207   if (!d)
 208     goto out;
 209
 210   while ((ent = readdir (d)))
 211     {
 212       char *full_name;
 213       struct stat s;
 214
 215       full_name = concat (p, "/", ent->d_name, NULL);
 216       if (stat(full_name, &s) == 0 && S_ISREG (s.st_mode))
 217         found = try_load_plugin (full_name);
 218       free (full_name);
 219       if (found)
 220         break;
 221     }
 222
 223  out:
 224   free (p);
 225   if (d)
 226     closedir (d);
 227
 228   return found;
 229 }
 230
 231
 232 static const bfd_target *
 233 bfd_plugin_object_p (bfd *abfd)
 234 {
 235   int claimed = 0;
 236   struct ld_plugin_input_file file;
 237   bfd *iobfd;
 238   static int have_loaded = 0;
 239   static int have_plugin = 0;
 240
 241   if (!have_loaded)
 242     {
 243       have_loaded = 1;
 244       have_plugin = load_plugin ();
 245     }
 246   if (!have_plugin)
 247     return NULL;
 248
 249   file.name = abfd->filename;
 250
 251   if (abfd->my_archive)
 252     {
 253       iobfd = abfd->my_archive;
 254       file.offset = abfd->origin;
 255       file.filesize = arelt_size (abfd);
 256     }
 257   else
 258     {
 259       iobfd = abfd;
 260       file.offset = 0;
 261       file.filesize = 0;
 262     }
 263
 264   if (!iobfd->iostream && !bfd_open_file (iobfd))
 265     return NULL;
 266
 267   file.fd = fileno ((FILE *) iobfd->iostream);
 268
 269   if (!abfd->my_archive)
 270     {
 271       struct stat stat_buf;
 272       if (fstat (file.fd, &stat_buf))
 273         return NULL;
 274       file.filesize = stat_buf.st_size;
 275     }
 276
 277   file.handle = abfd;
 278   off_t cur_offset = lseek(file.fd, 0, SEEK_CUR);
 279   claim_file (&file, &claimed);
 280   lseek(file.fd, cur_offset, SEEK_SET);
 281   if (!claimed)
 282     return NULL;
 283
 284   return abfd->xvec;
 285 }
 286
 287 /* Copy any private info we understand from the input bfd
 288    to the output bfd.  */
 289
 290 static bfd_boolean
 291 bfd_plugin_bfd_copy_private_bfd_data (bfd *ibfd ATTRIBUTE_UNUSED,
 292                                       bfd *obfd ATTRIBUTE_UNUSED)
 293 {
 294   BFD_ASSERT (0);
 295   return TRUE;
 296 }
 297
 298 /* Copy any private info we understand from the input section
 299    to the output section.  */
 300
 301 static bfd_boolean
 302 bfd_plugin_bfd_copy_private_section_data (bfd *ibfd ATTRIBUTE_UNUSED,
 303                                           asection *isection ATTRIBUTE_UNUSED,
 304                                           bfd *obfd ATTRIBUTE_UNUSED,
 305                                           asection *osection ATTRIBUTE_UNUSED)
 306 {
 307   BFD_ASSERT (0);
 308   return TRUE;
 309 }
 310
 311 /* Copy any private info we understand from the input symbol
 312    to the output symbol.  */
 313
 314 static bfd_boolean
 315 bfd_plugin_bfd_copy_private_symbol_data (bfd *ibfd ATTRIBUTE_UNUSED,
 316                                          asymbol *isymbol ATTRIBUTE_UNUSED,
 317                                          bfd *obfd ATTRIBUTE_UNUSED,
 318                                          asymbol *osymbol ATTRIBUTE_UNUSED)
 319 {
 320   BFD_ASSERT (0);
 321   return TRUE;
 322 }
 323
 324 static bfd_boolean
 325 bfd_plugin_bfd_print_private_bfd_data (bfd *abfd ATTRIBUTE_UNUSED, PTR ptr ATTRIBUTE_UNUSED)
 326 {
 327   BFD_ASSERT (0);
 328   return TRUE;
 329 }
 330
 331 static char *
 332 bfd_plugin_core_file_failing_command (bfd *abfd ATTRIBUTE_UNUSED)
 333 {
 334   BFD_ASSERT (0);
 335   return NULL;
 336 }
 337
 338 static int
 339 bfd_plugin_core_file_failing_signal (bfd *abfd ATTRIBUTE_UNUSED)
 340 {
 341   BFD_ASSERT (0);
 342   return 0;
 343 }
 344
 345 static int
 346 bfd_plugin_core_file_pid (bfd *abfd ATTRIBUTE_UNUSED)
 347 {
 348   BFD_ASSERT (0);
 349   return 0;
 350 }
 351
 352 static long
 353 bfd_plugin_get_symtab_upper_bound (bfd *abfd)
 354 {
 355   struct plugin_data_struct *plugin_data = abfd->tdata.plugin_data;
 356   long nsyms = plugin_data->nsyms;
 357
 358   BFD_ASSERT (nsyms >= 0);
 359
 360   return ((nsyms + 1) * sizeof (asymbol *));
 361 }
 362
 363 static flagword
 364 convert_flags (const struct ld_plugin_symbol *sym)
 365 {
 366  switch (sym->def)
 367    {
 368    case LDPK_DEF:
 369    case LDPK_COMMON:
 370    case LDPK_UNDEF:
 371      return BSF_GLOBAL;
 372
 373    case LDPK_WEAKUNDEF:
 374    case LDPK_WEAKDEF:
 375      return BSF_GLOBAL | BSF_WEAK;
 376
 377    default:
 378      BFD_ASSERT (0);
 379      return 0;
 380    }
 381 }
 382
 383 static long
 384 bfd_plugin_canonicalize_symtab (bfd *abfd,
 385                                 asymbol **alocation)
 386 {
 387   struct plugin_data_struct *plugin_data = abfd->tdata.plugin_data;
 388   long nsyms = plugin_data->nsyms;
 389   const struct ld_plugin_symbol *syms = plugin_data->syms;
 390   static asection fake_section;
 391   static asection fake_common_section;
 392   int i;
 393
 394   fake_section.name = ".text";
 395   fake_common_section.flags = SEC_IS_COMMON;
 396
 397   for (i = 0; i < nsyms; i++)
 398     {
 399       asymbol *s = bfd_alloc (abfd, sizeof (asymbol));
 400
 401       BFD_ASSERT (s);
 402       alocation[i] = s;
 403
 404       s->the_bfd = abfd;
 405       s->name = syms[i].name;
 406       s->value = 0;
 407       s->flags = convert_flags (&syms[i]);
 408       switch (syms[i].def)
 409         {
 410         case LDPK_COMMON:
 411           s->section = &fake_common_section;
 412           break;
 413         case LDPK_UNDEF:
 414         case LDPK_WEAKUNDEF:
 415           s->section = bfd_und_section_ptr;
 416           break;
 417         case LDPK_DEF:
 418         case LDPK_WEAKDEF:
 419           s->section = &fake_section;
 420           break;
 421         default:
 422           BFD_ASSERT (0);
 423         }
 424
 425       s->udata.p = (void *) &syms[i];
 426     }
 427
 428   return nsyms;
 429 }
 430
 431 static void
 432 bfd_plugin_print_symbol (bfd *abfd ATTRIBUTE_UNUSED,
 433                          PTR afile ATTRIBUTE_UNUSED,
 434                          asymbol *symbol ATTRIBUTE_UNUSED,
 435                          bfd_print_symbol_type how ATTRIBUTE_UNUSED)
 436 {
 437   BFD_ASSERT (0);
 438 }
 439
 440 static void
 441 bfd_plugin_get_symbol_info (bfd *abfd ATTRIBUTE_UNUSED,
 442                             asymbol *symbol,
 443                             symbol_info *ret)
 444 {
 445   bfd_symbol_info (symbol, ret);
 446 }
 447
 448 /* Make an empty symbol. */
 449
 450 static asymbol *
 451 bfd_plugin_make_empty_symbol (bfd *abfd)
 452 {
 453   asymbol *new_symbol = bfd_zalloc (abfd, sizeof (asymbol));
 454   if (new_symbol == NULL)
 455     return new_symbol;
 456   new_symbol->the_bfd = abfd;
 457   return new_symbol;
 458 }
 459
 460 static int
 461 bfd_plugin_sizeof_headers (bfd *a ATTRIBUTE_UNUSED,
 462                            struct bfd_link_info *info ATTRIBUTE_UNUSED)
 463 {
 464   BFD_ASSERT (0);
 465   return 0;
 466 }
 467
 468 const bfd_target plugin_vec =
 469 {
 470   "plugin",                     /* Name.  */
 471   bfd_target_unknown_flavour,
 472   BFD_ENDIAN_LITTLE,            /* Target byte order.  */
 473   BFD_ENDIAN_LITTLE,            /* Target headers byte order.  */
 474   (HAS_RELOC | EXEC_P |         /* Object flags.  */
 475    HAS_LINENO | HAS_DEBUG |
 476    HAS_SYMS | HAS_LOCALS | DYNAMIC | WP_TEXT | D_PAGED),
 477   (SEC_CODE | SEC_DATA | SEC_ROM | SEC_HAS_CONTENTS
 478    | SEC_ALLOC | SEC_LOAD | SEC_RELOC), /* Section flags.  */
 479   0,                            /* symbol_leading_char.  */
 480   '/',                          /* ar_pad_char.  */
 481   15,                           /* ar_max_namelen.  */
 482   0,                            /* match priority.  */
 483
 484   bfd_getl64, bfd_getl_signed_64, bfd_putl64,
 485   bfd_getl32, bfd_getl_signed_32, bfd_putl32,
 486   bfd_getl16, bfd_getl_signed_16, bfd_putl16,   /* data */
 487   bfd_getl64, bfd_getl_signed_64, bfd_putl64,
 488   bfd_getl32, bfd_getl_signed_32, bfd_putl32,
 489   bfd_getl16, bfd_getl_signed_16, bfd_putl16,   /* hdrs */
 490
 491   {                             /* bfd_check_format.  */
 492     _bfd_dummy_target,
 493     bfd_plugin_object_p,
 494     bfd_generic_archive_p,
 495     _bfd_dummy_target
 496   },
 497   {                             /* bfd_set_format.  */
 498     bfd_false,
 499     bfd_false,
 500     _bfd_generic_mkarchive,
 501     bfd_false,
 502   },
 503   {                             /* bfd_write_contents.  */
 504     bfd_false,
 505     bfd_false,
 506     _bfd_write_archive_contents,
 507     bfd_false,
 508   },
 509
 510   BFD_JUMP_TABLE_GENERIC (bfd_plugin),
 511   BFD_JUMP_TABLE_COPY (bfd_plugin),
 512   BFD_JUMP_TABLE_CORE (bfd_plugin),
 513   BFD_JUMP_TABLE_ARCHIVE (_bfd_archive_coff),
 514   BFD_JUMP_TABLE_SYMBOLS (bfd_plugin),
 515   BFD_JUMP_TABLE_RELOCS (_bfd_norelocs),
 516   BFD_JUMP_TABLE_WRITE (bfd_plugin),
 517   BFD_JUMP_TABLE_LINK (bfd_plugin),
 518   BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic),
 519
 520   NULL,
 521
 522   NULL                          /* backend_data.  */
 523 };
 524 #endif /* BFD_SUPPORTS_PLUGIN */