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