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 <assert.h>
  24 #include <dlfcn.h>
  25 #include <stdarg.h>
  26 #include "plugin-api.h"
  27 #include "sysdep.h"
  28 #include "plugin.h"
  29 #include "libbfd.h"
  30 #include "libiberty.h"
  31 #include <dirent.h>
  32
  33 #define bfd_plugin_close_and_cleanup                  _bfd_generic_close_and_cleanup
  34 #define bfd_plugin_bfd_free_cached_info               _bfd_generic_bfd_free_cached_info
  35 #define bfd_plugin_new_section_hook                   _bfd_generic_new_section_hook
  36 #define bfd_plugin_get_section_contents               _bfd_generic_get_section_contents
  37 #define bfd_plugin_get_section_contents_in_window     _bfd_generic_get_section_contents_in_window
  38 #define bfd_plugin_bfd_copy_private_header_data       _bfd_generic_bfd_copy_private_header_data
  39 #define bfd_plugin_bfd_merge_private_bfd_data         _bfd_generic_bfd_merge_private_bfd_data
  40 #define bfd_plugin_bfd_copy_private_header_data       _bfd_generic_bfd_copy_private_header_data
  41 #define bfd_plugin_bfd_set_private_flags              _bfd_generic_bfd_set_private_flags
  42 #define bfd_plugin_core_file_matches_executable_p     generic_core_file_matches_executable_p
  43 #define bfd_plugin_bfd_is_local_label_name            _bfd_nosymbols_bfd_is_local_label_name
  44 #define bfd_plugin_bfd_is_target_special_symbol       ((bfd_boolean (*) (bfd *, asymbol *)) bfd_false)
  45 #define bfd_plugin_get_lineno                         _bfd_nosymbols_get_lineno
  46 #define bfd_plugin_find_nearest_line                  _bfd_nosymbols_find_nearest_line
  47 #define bfd_plugin_find_inliner_info                  _bfd_nosymbols_find_inliner_info
  48 #define bfd_plugin_bfd_make_debug_symbol              _bfd_nosymbols_bfd_make_debug_symbol
  49 #define bfd_plugin_read_minisymbols                   _bfd_generic_read_minisymbols
  50 #define bfd_plugin_minisymbol_to_symbol               _bfd_generic_minisymbol_to_symbol
  51 #define bfd_plugin_set_arch_mach                      bfd_default_set_arch_mach
  52 #define bfd_plugin_set_section_contents               _bfd_generic_set_section_contents
  53 #define bfd_plugin_bfd_get_relocated_section_contents bfd_generic_get_relocated_section_contents
  54 #define bfd_plugin_bfd_relax_section                  bfd_generic_relax_section
  55 #define bfd_plugin_bfd_link_hash_table_create         _bfd_generic_link_hash_table_create
  56 #define bfd_plugin_bfd_link_hash_table_free           _bfd_generic_link_hash_table_free
  57 #define bfd_plugin_bfd_link_add_symbols               _bfd_generic_link_add_symbols
  58 #define bfd_plugin_bfd_link_just_syms                 _bfd_generic_link_just_syms
  59 #define bfd_plugin_bfd_final_link                     _bfd_generic_final_link
  60 #define bfd_plugin_bfd_link_split_section             _bfd_generic_link_split_section
  61 #define bfd_plugin_bfd_gc_sections                    bfd_generic_gc_sections
  62 #define bfd_plugin_bfd_merge_sections                 bfd_generic_merge_sections
  63 #define bfd_plugin_bfd_is_group_section               bfd_generic_is_group_section
  64 #define bfd_plugin_bfd_discard_group                  bfd_generic_discard_group
  65 #define bfd_plugin_section_already_linked             _bfd_generic_section_already_linked
  66 #define bfd_plugin_bfd_define_common_symbol           bfd_generic_define_common_symbol
  67
  68 static enum ld_plugin_status
  69 message (int level ATTRIBUTE_UNUSED,
  70          const char * format, ...)
  71 {
  72   va_list args;
  73   va_start (args, format);
  74   printf ("bfd plugin: ");
  75   vprintf (format, args);
  76   va_end (args);
  77   return LDPS_OK;
  78 }
  79
  80 /* Register a claim-file handler. */
  81 static ld_plugin_claim_file_handler claim_file;
  82
  83 static enum ld_plugin_status
  84 register_claim_file (ld_plugin_claim_file_handler handler)
  85 {
  86   claim_file = handler;
  87   return LDPS_OK;
  88 }
  89
  90 static enum ld_plugin_status
  91 add_symbols (void * handle,
  92              int nsyms,
  93              const struct ld_plugin_symbol * syms)
  94 {
  95   bfd *abfd = handle;
  96   struct plugin_data_struct *plugin_data =
  97     bfd_alloc (abfd, sizeof (plugin_data_struct));;
  98
  99   plugin_data->nsyms = nsyms;
 100   plugin_data->syms = syms;
 101
 102   if (nsyms != 0)
 103     abfd->flags |= HAS_SYMS;
 104
 105   abfd->tdata.plugin_data = plugin_data;
 106   return LDPS_OK;
 107 }
 108
 109 extern char *program_name __attribute__ ((weak));
 110
 111 static int
 112 try_load_plugin (const char *pname)
 113 {
 114   static void *plugin_handle;
 115   int tv_size = 4;
 116   struct ld_plugin_tv tv[tv_size];
 117   int i;
 118   ld_plugin_onload onload;
 119   enum ld_plugin_status status;
 120
 121   plugin_handle = dlopen (pname, RTLD_NOW);
 122   if (!plugin_handle)
 123     {
 124       (*_bfd_error_handler)("%s\n", dlerror ());
 125       return 0;
 126     }
 127
 128   onload = dlsym (plugin_handle, "onload");
 129   if (!onload)
 130     goto err;
 131
 132   i = 0;
 133   tv[i].tv_tag = LDPT_MESSAGE;
 134   tv[i].tv_u.tv_message = message;
 135
 136   ++i;
 137   tv[i].tv_tag = LDPT_REGISTER_CLAIM_FILE_HOOK;
 138   tv[i].tv_u.tv_register_claim_file = register_claim_file;
 139
 140   ++i;
 141   tv[i].tv_tag = LDPT_ADD_SYMBOLS;
 142   tv[i].tv_u.tv_add_symbols = add_symbols;
 143
 144   ++i;
 145   tv[i].tv_tag = LDPT_NULL;
 146   tv[i].tv_u.tv_val = 0;
 147
 148   status = (*onload)(tv);
 149
 150   if (status != LDPS_OK)
 151     goto err;
 152
 153   if (!claim_file)
 154     goto err;
 155
 156   return 1;
 157
 158  err:
 159   plugin_handle = NULL;
 160   return 0;
 161 }
 162
 163 static const char *plugin_name;
 164
 165 void
 166 bfd_plugin_set_plugin (const char *p)
 167 {
 168   plugin_name = p;
 169 }
 170
 171 static int
 172 load_plugin (void)
 173 {
 174   char *plugin_dir;
 175   char *p;
 176   DIR *d;
 177   struct dirent *ent;
 178   int found = 0;
 179
 180   if (plugin_name)
 181     return try_load_plugin (plugin_name);
 182
 183   if (!program_name)
 184     return 0;
 185
 186   plugin_dir = concat (BINDIR, "/../lib/bfd-plugins", NULL);
 187   p = make_relative_prefix (program_name,
 188                             BINDIR,
 189                             plugin_dir);
 190   free (plugin_dir);
 191   plugin_dir = NULL;
 192
 193   d = opendir (p);
 194   if (!d)
 195     goto out;
 196
 197   while ((ent = readdir (d)))
 198     {
 199       char *full_name;
 200       if (ent->d_type != DT_REG && ent->d_type != DT_LNK)
 201         continue;
 202
 203       full_name = concat (p, "/", ent->d_name, NULL);
 204       found = try_load_plugin (full_name);
 205       free (full_name);
 206       if (found)
 207         break;
 208     }
 209
 210  out:
 211   free (p);
 212   if (d)
 213     closedir (d);
 214
 215   return found;
 216 }
 217
 218
 219 static const bfd_target *
 220 bfd_plugin_object_p (bfd *abfd)
 221 {
 222   int claimed = 0;
 223   int t = load_plugin ();
 224   struct ld_plugin_input_file file;
 225   if (!t)
 226     return NULL;
 227
 228   file.name = abfd->filename;
 229
 230   if (abfd->iostream)
 231     {
 232       file.fd = fileno (abfd->iostream);
 233       file.offset = 0;
 234       file.filesize = 0; /*FIXME*/
 235     }
 236   else
 237     {
 238       bfd *archive = abfd->my_archive;
 239       BFD_ASSERT (archive);
 240       file.fd = fileno (archive->iostream);
 241       file.offset = abfd->origin;
 242       file.filesize = arelt_size (abfd);
 243
 244     }
 245   file.handle = abfd;
 246   claim_file (&file, &claimed);
 247   if (!claimed)
 248     return NULL;
 249
 250   return abfd->xvec;
 251 }
 252
 253 /* Copy any private info we understand from the input bfd
 254    to the output bfd.  */
 255
 256 static bfd_boolean
 257 bfd_plugin_bfd_copy_private_bfd_data (bfd *ibfd ATTRIBUTE_UNUSED,
 258                                       bfd *obfd ATTRIBUTE_UNUSED)
 259 {
 260   BFD_ASSERT (0);
 261   return TRUE;
 262 }
 263
 264 /* Copy any private info we understand from the input section
 265    to the output section.  */
 266
 267 static bfd_boolean
 268 bfd_plugin_bfd_copy_private_section_data (bfd *ibfd ATTRIBUTE_UNUSED,
 269                                           asection *isection ATTRIBUTE_UNUSED,
 270                                           bfd *obfd ATTRIBUTE_UNUSED,
 271                                           asection *osection ATTRIBUTE_UNUSED)
 272 {
 273   BFD_ASSERT (0);
 274   return TRUE;
 275 }
 276
 277 /* Copy any private info we understand from the input symbol
 278    to the output symbol.  */
 279
 280 static bfd_boolean
 281 bfd_plugin_bfd_copy_private_symbol_data (bfd *ibfd ATTRIBUTE_UNUSED,
 282                                          asymbol *isymbol ATTRIBUTE_UNUSED,
 283                                          bfd *obfd ATTRIBUTE_UNUSED,
 284                                          asymbol *osymbol ATTRIBUTE_UNUSED)
 285 {
 286   BFD_ASSERT (0);
 287   return TRUE;
 288 }
 289
 290 static bfd_boolean
 291 bfd_plugin_bfd_print_private_bfd_data (bfd *abfd ATTRIBUTE_UNUSED, PTR ptr ATTRIBUTE_UNUSED)
 292 {
 293   BFD_ASSERT (0);
 294   return TRUE;
 295 }
 296
 297 static char *
 298 bfd_plugin_core_file_failing_command (bfd *abfd ATTRIBUTE_UNUSED)
 299 {
 300   BFD_ASSERT (0);
 301   return NULL;
 302 }
 303
 304 static int
 305 bfd_plugin_core_file_failing_signal (bfd *abfd ATTRIBUTE_UNUSED)
 306 {
 307   BFD_ASSERT (0);
 308   return 0;
 309 }
 310
 311 static long
 312 bfd_plugin_get_symtab_upper_bound (bfd *abfd)
 313 {
 314   struct plugin_data_struct *plugin_data = abfd->tdata.plugin_data;
 315   long nsyms = plugin_data->nsyms;
 316
 317   BFD_ASSERT (nsyms >= 0);
 318
 319   return ((nsyms + 1) * sizeof (asymbol *));
 320 }
 321
 322 static flagword
 323 convert_flags (const struct ld_plugin_symbol *sym)
 324 {
 325  switch (sym->def)
 326    {
 327    case LDPK_DEF:
 328    case LDPK_COMMON:
 329    case LDPK_UNDEF:
 330      return BSF_GLOBAL;
 331
 332    case LDPK_WEAKUNDEF:
 333    case LDPK_WEAKDEF:
 334      return BSF_GLOBAL | BSF_WEAK;
 335
 336    default:
 337      BFD_ASSERT (0);
 338      return 0;
 339    }
 340 }
 341
 342 static long
 343 bfd_plugin_canonicalize_symtab (bfd *abfd,
 344                                 asymbol **alocation)
 345 {
 346   struct plugin_data_struct *plugin_data = abfd->tdata.plugin_data;
 347   long nsyms = plugin_data->nsyms;
 348   const struct ld_plugin_symbol *syms = plugin_data->syms;
 349   static asection fake_section;
 350   static asection fake_common_section;
 351   int i;
 352
 353   fake_section.name = ".text";
 354   fake_common_section.flags = SEC_IS_COMMON;
 355
 356   for (i = 0; i < nsyms; i++)
 357     {
 358       asymbol *s = bfd_alloc (abfd, sizeof (asymbol));
 359
 360       BFD_ASSERT (s);
 361       alocation[i] = s;
 362
 363       s->the_bfd = abfd;
 364       s->name = syms[i].name;
 365       s->value = 0;
 366       s->flags = convert_flags (&syms[i]);
 367       switch (syms[i].def)
 368         {
 369         case LDPK_COMMON:
 370           s->section = &fake_common_section;
 371           break;
 372         case LDPK_UNDEF:
 373         case LDPK_WEAKUNDEF:
 374           s->section = bfd_und_section_ptr;
 375           break;
 376         case LDPK_DEF:
 377         case LDPK_WEAKDEF:
 378           s->section = &fake_section;
 379           break;
 380         default:
 381           BFD_ASSERT (0);
 382         }
 383
 384       s->udata.p = (void *) &syms[i];
 385     }
 386
 387   return nsyms;
 388 }
 389
 390 static void
 391 bfd_plugin_print_symbol (bfd *abfd ATTRIBUTE_UNUSED,
 392                          PTR afile ATTRIBUTE_UNUSED,
 393                          asymbol *symbol ATTRIBUTE_UNUSED,
 394                          bfd_print_symbol_type how ATTRIBUTE_UNUSED)
 395 {
 396   BFD_ASSERT (0);
 397 }
 398
 399 static void
 400 bfd_plugin_get_symbol_info (bfd *abfd ATTRIBUTE_UNUSED,
 401                             asymbol *symbol,
 402                             symbol_info *ret)
 403 {
 404   bfd_symbol_info (symbol, ret);
 405 }
 406
 407 /* Make an empty symbol. */
 408
 409 static asymbol *
 410 bfd_plugin_make_empty_symbol (bfd *abfd)
 411 {
 412   asymbol *new = bfd_zalloc (abfd, sizeof (asymbol));
 413   if (new == NULL)
 414     return new;
 415   new->the_bfd = abfd;
 416   return new;
 417 }
 418
 419 static int
 420 bfd_plugin_sizeof_headers (bfd *a ATTRIBUTE_UNUSED,
 421                            struct bfd_link_info *info ATTRIBUTE_UNUSED)
 422 {
 423   BFD_ASSERT (0);
 424   return 0;
 425 }
 426
 427 static bfd_boolean
 428 bfd_plugin_mkobject (bfd *abfd ATTRIBUTE_UNUSED)
 429 {
 430   BFD_ASSERT (0);
 431   return 0;
 432 }
 433
 434 const bfd_target plugin_vec =
 435 {
 436   "plugin",                     /* Name.  */
 437   bfd_target_unknown_flavour,
 438   BFD_ENDIAN_LITTLE,            /* Target byte order.  */
 439   BFD_ENDIAN_LITTLE,            /* Target headers byte order.  */
 440   (HAS_RELOC | EXEC_P |         /* Object flags.  */
 441    HAS_LINENO | HAS_DEBUG |
 442    HAS_SYMS | HAS_LOCALS | DYNAMIC | WP_TEXT | D_PAGED),
 443   (SEC_CODE | SEC_DATA | SEC_ROM | SEC_HAS_CONTENTS
 444    | SEC_ALLOC | SEC_LOAD | SEC_RELOC), /* Section flags.  */
 445   0,                            /* symbol_leading_char.  */
 446   '/',                          /* ar_pad_char.  */
 447   15,                           /* ar_max_namelen.  */
 448
 449   bfd_getl64, bfd_getl_signed_64, bfd_putl64,
 450   bfd_getl32, bfd_getl_signed_32, bfd_putl32,
 451   bfd_getl16, bfd_getl_signed_16, bfd_putl16,   /* data */
 452   bfd_getl64, bfd_getl_signed_64, bfd_putl64,
 453   bfd_getl32, bfd_getl_signed_32, bfd_putl32,
 454   bfd_getl16, bfd_getl_signed_16, bfd_putl16,   /* hdrs */
 455
 456   {                             /* bfd_check_format.  */
 457     _bfd_dummy_target,
 458     bfd_plugin_object_p,
 459     bfd_generic_archive_p,
 460     _bfd_dummy_target
 461   },
 462   {                             /* bfd_set_format.  */
 463     bfd_false,
 464     bfd_plugin_mkobject,
 465     _bfd_generic_mkarchive,
 466     bfd_false,
 467   },
 468   {                             /* bfd_write_contents.  */
 469     bfd_false,
 470     bfd_false,
 471     _bfd_write_archive_contents,
 472     bfd_false,
 473   },
 474
 475   BFD_JUMP_TABLE_GENERIC (bfd_plugin),
 476   BFD_JUMP_TABLE_COPY (bfd_plugin),
 477   BFD_JUMP_TABLE_CORE (bfd_plugin),
 478   BFD_JUMP_TABLE_ARCHIVE (_bfd_archive_coff),
 479   BFD_JUMP_TABLE_SYMBOLS (bfd_plugin),
 480   BFD_JUMP_TABLE_RELOCS (_bfd_norelocs),
 481   BFD_JUMP_TABLE_WRITE (bfd_plugin),
 482   BFD_JUMP_TABLE_LINK (bfd_plugin),
 483   BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic),
 484
 485   NULL,
 486
 487   NULL                          /* backend_data.  */
 488 };