| 1 | /* BFD back-end for linux flavored i386 a.out binaries. |
| 2 | Copyright 1992, 1993, 1994, 1995, 1996, 1997, 1999, 2001, 2002, 2003, |
| 3 | 2004, 2006, 2007, 2008 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 | #define TARGET_PAGE_SIZE 4096 |
| 23 | #define ZMAGIC_DISK_BLOCK_SIZE 1024 |
| 24 | #define SEGMENT_SIZE TARGET_PAGE_SIZE |
| 25 | #define TEXT_START_ADDR 0x0 |
| 26 | #define N_SHARED_LIB(x) 0 |
| 27 | |
| 28 | #define MACHTYPE_OK(mtype) ((mtype) == M_386 || (mtype) == M_UNKNOWN) |
| 29 | |
| 30 | #include "sysdep.h" |
| 31 | #include "bfd.h" |
| 32 | #include "libbfd.h" |
| 33 | #include "aout/aout64.h" |
| 34 | #include "aout/stab_gnu.h" |
| 35 | #include "aout/ar.h" |
| 36 | #include "libaout.h" /* BFD a.out internal data structures */ |
| 37 | |
| 38 | #define DEFAULT_ARCH bfd_arch_i386 |
| 39 | |
| 40 | /* Do not "beautify" the CONCAT* macro args. Traditional C will not |
| 41 | remove whitespace added here, and thus will fail to concatenate |
| 42 | the tokens. */ |
| 43 | #define MY(OP) CONCAT2 (i386linux_,OP) |
| 44 | #define TARGETNAME "a.out-i386-linux" |
| 45 | |
| 46 | extern const bfd_target MY(vec); |
| 47 | |
| 48 | /* We always generate QMAGIC files in preference to ZMAGIC files. It |
| 49 | would be possible to make this a linker option, if that ever |
| 50 | becomes important. */ |
| 51 | |
| 52 | static void MY_final_link_callback |
| 53 | PARAMS ((bfd *, file_ptr *, file_ptr *, file_ptr *)); |
| 54 | static bfd_boolean i386linux_bfd_final_link |
| 55 | PARAMS ((bfd *, struct bfd_link_info *)); |
| 56 | static bfd_boolean i386linux_write_object_contents PARAMS ((bfd *)); |
| 57 | |
| 58 | static bfd_boolean |
| 59 | i386linux_bfd_final_link (abfd, info) |
| 60 | bfd *abfd; |
| 61 | struct bfd_link_info *info; |
| 62 | { |
| 63 | obj_aout_subformat (abfd) = q_magic_format; |
| 64 | return NAME(aout,final_link) (abfd, info, MY_final_link_callback); |
| 65 | } |
| 66 | |
| 67 | #define MY_bfd_final_link i386linux_bfd_final_link |
| 68 | |
| 69 | /* Set the machine type correctly. */ |
| 70 | |
| 71 | static bfd_boolean |
| 72 | i386linux_write_object_contents (abfd) |
| 73 | bfd *abfd; |
| 74 | { |
| 75 | struct external_exec exec_bytes; |
| 76 | struct internal_exec *execp = exec_hdr (abfd); |
| 77 | |
| 78 | N_SET_MACHTYPE (*execp, M_386); |
| 79 | |
| 80 | obj_reloc_entry_size (abfd) = RELOC_STD_SIZE; |
| 81 | |
| 82 | WRITE_HEADERS(abfd, execp); |
| 83 | |
| 84 | return TRUE; |
| 85 | } |
| 86 | |
| 87 | #define MY_write_object_contents i386linux_write_object_contents |
| 88 | \f |
| 89 | /* Code to link against Linux a.out shared libraries. */ |
| 90 | |
| 91 | /* See if a symbol name is a reference to the global offset table. */ |
| 92 | |
| 93 | #ifndef GOT_REF_PREFIX |
| 94 | #define GOT_REF_PREFIX "__GOT_" |
| 95 | #endif |
| 96 | |
| 97 | #define IS_GOT_SYM(name) (CONST_STRNEQ (name, GOT_REF_PREFIX)) |
| 98 | |
| 99 | /* See if a symbol name is a reference to the procedure linkage table. */ |
| 100 | |
| 101 | #ifndef PLT_REF_PREFIX |
| 102 | #define PLT_REF_PREFIX "__PLT_" |
| 103 | #endif |
| 104 | |
| 105 | #define IS_PLT_SYM(name) (CONST_STRNEQ (name, PLT_REF_PREFIX)) |
| 106 | |
| 107 | /* This string is used to generate specialized error messages. */ |
| 108 | |
| 109 | #ifndef NEEDS_SHRLIB |
| 110 | #define NEEDS_SHRLIB "__NEEDS_SHRLIB_" |
| 111 | #endif |
| 112 | |
| 113 | /* This special symbol is a set vector that contains a list of |
| 114 | pointers to fixup tables. It will be present in any dynamically |
| 115 | linked file. The linker generated fixup table should also be added |
| 116 | to the list, and it should always appear in the second slot (the |
| 117 | first one is a dummy with a magic number that is defined in |
| 118 | crt0.o). */ |
| 119 | |
| 120 | #ifndef SHARABLE_CONFLICTS |
| 121 | #define SHARABLE_CONFLICTS "__SHARABLE_CONFLICTS__" |
| 122 | #endif |
| 123 | |
| 124 | /* We keep a list of fixups. The terminology is a bit strange, but |
| 125 | each fixup contains two 32 bit numbers. A regular fixup contains |
| 126 | an address and a pointer, and at runtime we should store the |
| 127 | address at the location pointed to by the pointer. A builtin fixup |
| 128 | contains two pointers, and we should read the address using one |
| 129 | pointer and store it at the location pointed to by the other |
| 130 | pointer. Builtin fixups come into play when we have duplicate |
| 131 | __GOT__ symbols for the same variable. The builtin fixup will copy |
| 132 | the GOT pointer from one over into the other. */ |
| 133 | |
| 134 | struct fixup |
| 135 | { |
| 136 | struct fixup *next; |
| 137 | struct linux_link_hash_entry *h; |
| 138 | bfd_vma value; |
| 139 | |
| 140 | /* Nonzero if this is a jump instruction that needs to be fixed, |
| 141 | zero if this is just a pointer */ |
| 142 | char jump; |
| 143 | |
| 144 | char builtin; |
| 145 | }; |
| 146 | |
| 147 | /* We don't need a special hash table entry structure, but we do need |
| 148 | to keep some information between linker passes, so we use a special |
| 149 | hash table. */ |
| 150 | |
| 151 | struct linux_link_hash_entry |
| 152 | { |
| 153 | struct aout_link_hash_entry root; |
| 154 | }; |
| 155 | |
| 156 | struct linux_link_hash_table |
| 157 | { |
| 158 | struct aout_link_hash_table root; |
| 159 | |
| 160 | /* First dynamic object found in link. */ |
| 161 | bfd *dynobj; |
| 162 | |
| 163 | /* Number of fixups. */ |
| 164 | size_t fixup_count; |
| 165 | |
| 166 | /* Number of builtin fixups. */ |
| 167 | size_t local_builtins; |
| 168 | |
| 169 | /* List of fixups. */ |
| 170 | struct fixup *fixup_list; |
| 171 | }; |
| 172 | |
| 173 | static struct bfd_hash_entry *linux_link_hash_newfunc |
| 174 | PARAMS ((struct bfd_hash_entry *, struct bfd_hash_table *, const char *)); |
| 175 | static struct bfd_link_hash_table *linux_link_hash_table_create |
| 176 | PARAMS ((bfd *)); |
| 177 | static struct fixup *new_fixup |
| 178 | PARAMS ((struct bfd_link_info *, struct linux_link_hash_entry *, |
| 179 | bfd_vma, int)); |
| 180 | static bfd_boolean linux_link_create_dynamic_sections |
| 181 | PARAMS ((bfd *, struct bfd_link_info *)); |
| 182 | static bfd_boolean linux_add_one_symbol |
| 183 | PARAMS ((struct bfd_link_info *, bfd *, const char *, flagword, asection *, |
| 184 | bfd_vma, const char *, bfd_boolean, bfd_boolean, |
| 185 | struct bfd_link_hash_entry **)); |
| 186 | static bfd_boolean linux_tally_symbols |
| 187 | PARAMS ((struct linux_link_hash_entry *, PTR)); |
| 188 | static bfd_boolean linux_finish_dynamic_link |
| 189 | PARAMS ((bfd *, struct bfd_link_info *)); |
| 190 | |
| 191 | /* Routine to create an entry in an Linux link hash table. */ |
| 192 | |
| 193 | static struct bfd_hash_entry * |
| 194 | linux_link_hash_newfunc (entry, table, string) |
| 195 | struct bfd_hash_entry *entry; |
| 196 | struct bfd_hash_table *table; |
| 197 | const char *string; |
| 198 | { |
| 199 | struct linux_link_hash_entry *ret = (struct linux_link_hash_entry *) entry; |
| 200 | |
| 201 | /* Allocate the structure if it has not already been allocated by a |
| 202 | subclass. */ |
| 203 | if (ret == (struct linux_link_hash_entry *) NULL) |
| 204 | ret = ((struct linux_link_hash_entry *) |
| 205 | bfd_hash_allocate (table, sizeof (struct linux_link_hash_entry))); |
| 206 | if (ret == NULL) |
| 207 | return (struct bfd_hash_entry *) ret; |
| 208 | |
| 209 | /* Call the allocation method of the superclass. */ |
| 210 | ret = ((struct linux_link_hash_entry *) |
| 211 | NAME(aout,link_hash_newfunc) ((struct bfd_hash_entry *) ret, |
| 212 | table, string)); |
| 213 | if (ret != NULL) |
| 214 | { |
| 215 | /* Set local fields; there aren't any. */ |
| 216 | } |
| 217 | |
| 218 | return (struct bfd_hash_entry *) ret; |
| 219 | } |
| 220 | |
| 221 | /* Create a Linux link hash table. */ |
| 222 | |
| 223 | static struct bfd_link_hash_table * |
| 224 | linux_link_hash_table_create (abfd) |
| 225 | bfd *abfd; |
| 226 | { |
| 227 | struct linux_link_hash_table *ret; |
| 228 | bfd_size_type amt = sizeof (struct linux_link_hash_table); |
| 229 | |
| 230 | ret = (struct linux_link_hash_table *) bfd_alloc (abfd, amt); |
| 231 | if (ret == (struct linux_link_hash_table *) NULL) |
| 232 | return (struct bfd_link_hash_table *) NULL; |
| 233 | if (!NAME(aout,link_hash_table_init) (&ret->root, abfd, |
| 234 | linux_link_hash_newfunc, |
| 235 | sizeof (struct linux_link_hash_entry))) |
| 236 | { |
| 237 | free (ret); |
| 238 | return (struct bfd_link_hash_table *) NULL; |
| 239 | } |
| 240 | |
| 241 | ret->dynobj = NULL; |
| 242 | ret->fixup_count = 0; |
| 243 | ret->local_builtins = 0; |
| 244 | ret->fixup_list = NULL; |
| 245 | |
| 246 | return &ret->root.root; |
| 247 | } |
| 248 | |
| 249 | /* Look up an entry in a Linux link hash table. */ |
| 250 | |
| 251 | #define linux_link_hash_lookup(table, string, create, copy, follow) \ |
| 252 | ((struct linux_link_hash_entry *) \ |
| 253 | aout_link_hash_lookup (&(table)->root, (string), (create), (copy),\ |
| 254 | (follow))) |
| 255 | |
| 256 | /* Traverse a Linux link hash table. */ |
| 257 | |
| 258 | #define linux_link_hash_traverse(table, func, info) \ |
| 259 | (aout_link_hash_traverse \ |
| 260 | (&(table)->root, \ |
| 261 | (bfd_boolean (*) PARAMS ((struct aout_link_hash_entry *, PTR))) (func), \ |
| 262 | (info))) |
| 263 | |
| 264 | /* Get the Linux link hash table from the info structure. This is |
| 265 | just a cast. */ |
| 266 | |
| 267 | #define linux_hash_table(p) ((struct linux_link_hash_table *) ((p)->hash)) |
| 268 | |
| 269 | /* Store the information for a new fixup. */ |
| 270 | |
| 271 | static struct fixup * |
| 272 | new_fixup (info, h, value, builtin) |
| 273 | struct bfd_link_info *info; |
| 274 | struct linux_link_hash_entry *h; |
| 275 | bfd_vma value; |
| 276 | int builtin; |
| 277 | { |
| 278 | struct fixup *f; |
| 279 | |
| 280 | f = (struct fixup *) bfd_hash_allocate (&info->hash->table, |
| 281 | sizeof (struct fixup)); |
| 282 | if (f == NULL) |
| 283 | return f; |
| 284 | f->next = linux_hash_table (info)->fixup_list; |
| 285 | linux_hash_table (info)->fixup_list = f; |
| 286 | f->h = h; |
| 287 | f->value = value; |
| 288 | f->builtin = builtin; |
| 289 | f->jump = 0; |
| 290 | ++linux_hash_table (info)->fixup_count; |
| 291 | return f; |
| 292 | } |
| 293 | |
| 294 | /* We come here once we realize that we are going to link to a shared |
| 295 | library. We need to create a special section that contains the |
| 296 | fixup table, and we ultimately need to add a pointer to this into |
| 297 | the set vector for SHARABLE_CONFLICTS. At this point we do not |
| 298 | know the size of the section, but that's OK - we just need to |
| 299 | create it for now. */ |
| 300 | |
| 301 | static bfd_boolean |
| 302 | linux_link_create_dynamic_sections (abfd, info) |
| 303 | bfd *abfd; |
| 304 | struct bfd_link_info *info ATTRIBUTE_UNUSED; |
| 305 | { |
| 306 | flagword flags; |
| 307 | register asection *s; |
| 308 | |
| 309 | /* Note that we set the SEC_IN_MEMORY flag. */ |
| 310 | flags = SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS | SEC_IN_MEMORY; |
| 311 | |
| 312 | /* We choose to use the name ".linux-dynamic" for the fixup table. |
| 313 | Why not? */ |
| 314 | s = bfd_make_section_with_flags (abfd, ".linux-dynamic", flags); |
| 315 | if (s == NULL |
| 316 | || ! bfd_set_section_alignment (abfd, s, 2)) |
| 317 | return FALSE; |
| 318 | s->size = 0; |
| 319 | s->contents = 0; |
| 320 | |
| 321 | return TRUE; |
| 322 | } |
| 323 | |
| 324 | /* Function to add a single symbol to the linker hash table. This is |
| 325 | a wrapper around _bfd_generic_link_add_one_symbol which handles the |
| 326 | tweaking needed for dynamic linking support. */ |
| 327 | |
| 328 | static bfd_boolean |
| 329 | linux_add_one_symbol (info, abfd, name, flags, section, value, string, |
| 330 | copy, collect, hashp) |
| 331 | struct bfd_link_info *info; |
| 332 | bfd *abfd; |
| 333 | const char *name; |
| 334 | flagword flags; |
| 335 | asection *section; |
| 336 | bfd_vma value; |
| 337 | const char *string; |
| 338 | bfd_boolean copy; |
| 339 | bfd_boolean collect; |
| 340 | struct bfd_link_hash_entry **hashp; |
| 341 | { |
| 342 | struct linux_link_hash_entry *h; |
| 343 | bfd_boolean insert; |
| 344 | |
| 345 | /* Look up and see if we already have this symbol in the hash table. |
| 346 | If we do, and the defining entry is from a shared library, we |
| 347 | need to create the dynamic sections. |
| 348 | |
| 349 | FIXME: What if abfd->xvec != info->output_bfd->xvec? We may |
| 350 | want to be able to link Linux a.out and ELF objects together, |
| 351 | but serious confusion is possible. */ |
| 352 | |
| 353 | insert = FALSE; |
| 354 | |
| 355 | if (! info->relocatable |
| 356 | && linux_hash_table (info)->dynobj == NULL |
| 357 | && strcmp (name, SHARABLE_CONFLICTS) == 0 |
| 358 | && (flags & BSF_CONSTRUCTOR) != 0 |
| 359 | && abfd->xvec == info->output_bfd->xvec) |
| 360 | { |
| 361 | if (! linux_link_create_dynamic_sections (abfd, info)) |
| 362 | return FALSE; |
| 363 | linux_hash_table (info)->dynobj = abfd; |
| 364 | insert = TRUE; |
| 365 | } |
| 366 | |
| 367 | if (bfd_is_abs_section (section) |
| 368 | && abfd->xvec == info->output_bfd->xvec) |
| 369 | { |
| 370 | h = linux_link_hash_lookup (linux_hash_table (info), name, FALSE, |
| 371 | FALSE, FALSE); |
| 372 | if (h != NULL |
| 373 | && (h->root.root.type == bfd_link_hash_defined |
| 374 | || h->root.root.type == bfd_link_hash_defweak)) |
| 375 | { |
| 376 | struct fixup *f; |
| 377 | |
| 378 | if (hashp != NULL) |
| 379 | *hashp = (struct bfd_link_hash_entry *) h; |
| 380 | |
| 381 | f = new_fixup (info, h, value, ! IS_PLT_SYM (name)); |
| 382 | if (f == NULL) |
| 383 | return FALSE; |
| 384 | f->jump = IS_PLT_SYM (name); |
| 385 | |
| 386 | return TRUE; |
| 387 | } |
| 388 | } |
| 389 | |
| 390 | /* Do the usual procedure for adding a symbol. */ |
| 391 | if (! _bfd_generic_link_add_one_symbol (info, abfd, name, flags, section, |
| 392 | value, string, copy, collect, |
| 393 | hashp)) |
| 394 | return FALSE; |
| 395 | |
| 396 | /* Insert a pointer to our table in the set vector. The dynamic |
| 397 | linker requires this information */ |
| 398 | if (insert) |
| 399 | { |
| 400 | asection *s; |
| 401 | |
| 402 | /* Here we do our special thing to add the pointer to the |
| 403 | dynamic section in the SHARABLE_CONFLICTS set vector. */ |
| 404 | s = bfd_get_section_by_name (linux_hash_table (info)->dynobj, |
| 405 | ".linux-dynamic"); |
| 406 | BFD_ASSERT (s != NULL); |
| 407 | |
| 408 | if (! (_bfd_generic_link_add_one_symbol |
| 409 | (info, linux_hash_table (info)->dynobj, SHARABLE_CONFLICTS, |
| 410 | BSF_GLOBAL | BSF_CONSTRUCTOR, s, (bfd_vma) 0, NULL, |
| 411 | FALSE, FALSE, NULL))) |
| 412 | return FALSE; |
| 413 | } |
| 414 | |
| 415 | return TRUE; |
| 416 | } |
| 417 | |
| 418 | /* We will crawl the hash table and come here for every global symbol. |
| 419 | We will examine each entry and see if there are indications that we |
| 420 | need to add a fixup. There are two possible cases - one is where |
| 421 | you have duplicate definitions of PLT or GOT symbols - these will |
| 422 | have already been caught and added as "builtin" fixups. If we find |
| 423 | that the corresponding non PLT/GOT symbol is also present, we |
| 424 | convert it to a regular fixup instead. |
| 425 | |
| 426 | This function is called via linux_link_hash_traverse. */ |
| 427 | |
| 428 | static bfd_boolean |
| 429 | linux_tally_symbols (h, data) |
| 430 | struct linux_link_hash_entry *h; |
| 431 | PTR data; |
| 432 | { |
| 433 | struct bfd_link_info *info = (struct bfd_link_info *) data; |
| 434 | struct fixup *f, *f1; |
| 435 | int is_plt; |
| 436 | struct linux_link_hash_entry *h1, *h2; |
| 437 | bfd_boolean exists; |
| 438 | |
| 439 | if (h->root.root.type == bfd_link_hash_warning) |
| 440 | h = (struct linux_link_hash_entry *) h->root.root.u.i.link; |
| 441 | |
| 442 | if (h->root.root.type == bfd_link_hash_undefined |
| 443 | && CONST_STRNEQ (h->root.root.root.string, NEEDS_SHRLIB)) |
| 444 | { |
| 445 | const char *name; |
| 446 | char *p; |
| 447 | char *alloc = NULL; |
| 448 | |
| 449 | name = h->root.root.root.string + sizeof NEEDS_SHRLIB - 1; |
| 450 | p = strrchr (name, '_'); |
| 451 | if (p != NULL) |
| 452 | alloc = (char *) bfd_malloc ((bfd_size_type) strlen (name) + 1); |
| 453 | |
| 454 | if (p == NULL || alloc == NULL) |
| 455 | (*_bfd_error_handler) (_("Output file requires shared library `%s'\n"), |
| 456 | name); |
| 457 | else |
| 458 | { |
| 459 | strcpy (alloc, name); |
| 460 | p = strrchr (alloc, '_'); |
| 461 | *p++ = '\0'; |
| 462 | (*_bfd_error_handler) |
| 463 | (_("Output file requires shared library `%s.so.%s'\n"), |
| 464 | alloc, p); |
| 465 | free (alloc); |
| 466 | } |
| 467 | |
| 468 | abort (); |
| 469 | } |
| 470 | |
| 471 | /* If this symbol is not a PLT/GOT, we do not even need to look at it */ |
| 472 | is_plt = IS_PLT_SYM (h->root.root.root.string); |
| 473 | |
| 474 | if (is_plt || IS_GOT_SYM (h->root.root.root.string)) |
| 475 | { |
| 476 | /* Look up this symbol twice. Once just as a regular lookup, |
| 477 | and then again following all of the indirect links until we |
| 478 | reach a real symbol. */ |
| 479 | h1 = linux_link_hash_lookup (linux_hash_table (info), |
| 480 | (h->root.root.root.string |
| 481 | + sizeof PLT_REF_PREFIX - 1), |
| 482 | FALSE, FALSE, TRUE); |
| 483 | /* h2 does not follow indirect symbols. */ |
| 484 | h2 = linux_link_hash_lookup (linux_hash_table (info), |
| 485 | (h->root.root.root.string |
| 486 | + sizeof PLT_REF_PREFIX - 1), |
| 487 | FALSE, FALSE, FALSE); |
| 488 | |
| 489 | /* The real symbol must exist but if it is also an ABS symbol, |
| 490 | there is no need to have a fixup. This is because they both |
| 491 | came from the same library. If on the other hand, we had to |
| 492 | use an indirect symbol to get to the real symbol, we add the |
| 493 | fixup anyway, since there are cases where these symbols come |
| 494 | from different shared libraries */ |
| 495 | if (h1 != NULL |
| 496 | && (((h1->root.root.type == bfd_link_hash_defined |
| 497 | || h1->root.root.type == bfd_link_hash_defweak) |
| 498 | && ! bfd_is_abs_section (h1->root.root.u.def.section)) |
| 499 | || h2->root.root.type == bfd_link_hash_indirect)) |
| 500 | { |
| 501 | /* See if there is a "builtin" fixup already present |
| 502 | involving this symbol. If so, convert it to a regular |
| 503 | fixup. In the end, this relaxes some of the requirements |
| 504 | about the order of performing fixups. */ |
| 505 | exists = FALSE; |
| 506 | for (f1 = linux_hash_table (info)->fixup_list; |
| 507 | f1 != NULL; |
| 508 | f1 = f1->next) |
| 509 | { |
| 510 | if ((f1->h != h && f1->h != h1) |
| 511 | || (! f1->builtin && ! f1->jump)) |
| 512 | continue; |
| 513 | if (f1->h == h1) |
| 514 | exists = TRUE; |
| 515 | if (! exists |
| 516 | && bfd_is_abs_section (h->root.root.u.def.section)) |
| 517 | { |
| 518 | f = new_fixup (info, h1, f1->h->root.root.u.def.value, 0); |
| 519 | f->jump = is_plt; |
| 520 | } |
| 521 | f1->h = h1; |
| 522 | f1->jump = is_plt; |
| 523 | f1->builtin = 0; |
| 524 | exists = TRUE; |
| 525 | } |
| 526 | if (! exists |
| 527 | && bfd_is_abs_section (h->root.root.u.def.section)) |
| 528 | { |
| 529 | f = new_fixup (info, h1, h->root.root.u.def.value, 0); |
| 530 | if (f == NULL) |
| 531 | { |
| 532 | /* FIXME: No way to return error. */ |
| 533 | abort (); |
| 534 | } |
| 535 | f->jump = is_plt; |
| 536 | } |
| 537 | } |
| 538 | |
| 539 | /* Quick and dirty way of stripping these symbols from the |
| 540 | symtab. */ |
| 541 | if (bfd_is_abs_section (h->root.root.u.def.section)) |
| 542 | h->root.written = TRUE; |
| 543 | } |
| 544 | |
| 545 | return TRUE; |
| 546 | } |
| 547 | |
| 548 | /* This is called to set the size of the .linux-dynamic section is. |
| 549 | It is called by the Linux linker emulation before_allocation |
| 550 | routine. We have finished reading all of the input files, and now |
| 551 | we just scan the hash tables to find out how many additional fixups |
| 552 | are required. */ |
| 553 | |
| 554 | bfd_boolean |
| 555 | bfd_i386linux_size_dynamic_sections (output_bfd, info) |
| 556 | bfd *output_bfd; |
| 557 | struct bfd_link_info *info; |
| 558 | { |
| 559 | struct fixup *f; |
| 560 | asection *s; |
| 561 | |
| 562 | if (output_bfd->xvec != &MY(vec)) |
| 563 | return TRUE; |
| 564 | |
| 565 | /* First find the fixups... */ |
| 566 | linux_link_hash_traverse (linux_hash_table (info), |
| 567 | linux_tally_symbols, |
| 568 | (PTR) info); |
| 569 | |
| 570 | /* If there are builtin fixups, leave room for a marker. This is |
| 571 | used by the dynamic linker so that it knows that all that follow |
| 572 | are builtin fixups instead of regular fixups. */ |
| 573 | for (f = linux_hash_table (info)->fixup_list; f != NULL; f = f->next) |
| 574 | { |
| 575 | if (f->builtin) |
| 576 | { |
| 577 | ++linux_hash_table (info)->fixup_count; |
| 578 | ++linux_hash_table (info)->local_builtins; |
| 579 | break; |
| 580 | } |
| 581 | } |
| 582 | |
| 583 | if (linux_hash_table (info)->dynobj == NULL) |
| 584 | { |
| 585 | if (linux_hash_table (info)->fixup_count > 0) |
| 586 | abort (); |
| 587 | return TRUE; |
| 588 | } |
| 589 | |
| 590 | /* Allocate memory for our fixup table. We will fill it in later. */ |
| 591 | s = bfd_get_section_by_name (linux_hash_table (info)->dynobj, |
| 592 | ".linux-dynamic"); |
| 593 | if (s != NULL) |
| 594 | { |
| 595 | s->size = linux_hash_table (info)->fixup_count + 1; |
| 596 | s->size *= 8; |
| 597 | s->contents = (bfd_byte *) bfd_zalloc (output_bfd, s->size); |
| 598 | if (s->contents == NULL) |
| 599 | return FALSE; |
| 600 | } |
| 601 | |
| 602 | return TRUE; |
| 603 | } |
| 604 | |
| 605 | /* We come here once we are ready to actually write the fixup table to |
| 606 | the output file. Scan the fixup tables and so forth and generate |
| 607 | the stuff we need. */ |
| 608 | |
| 609 | static bfd_boolean |
| 610 | linux_finish_dynamic_link (output_bfd, info) |
| 611 | bfd *output_bfd; |
| 612 | struct bfd_link_info *info; |
| 613 | { |
| 614 | asection *s, *os, *is; |
| 615 | bfd_byte *fixup_table; |
| 616 | struct linux_link_hash_entry *h; |
| 617 | struct fixup *f; |
| 618 | unsigned int new_addr; |
| 619 | int section_offset; |
| 620 | unsigned int fixups_written; |
| 621 | |
| 622 | if (linux_hash_table (info)->dynobj == NULL) |
| 623 | return TRUE; |
| 624 | |
| 625 | s = bfd_get_section_by_name (linux_hash_table (info)->dynobj, |
| 626 | ".linux-dynamic"); |
| 627 | BFD_ASSERT (s != NULL); |
| 628 | os = s->output_section; |
| 629 | fixups_written = 0; |
| 630 | |
| 631 | #ifdef LINUX_LINK_DEBUG |
| 632 | printf ("Fixup table file offset: %x VMA: %x\n", |
| 633 | os->filepos + s->output_offset, |
| 634 | os->vma + s->output_offset); |
| 635 | #endif |
| 636 | |
| 637 | fixup_table = s->contents; |
| 638 | bfd_put_32 (output_bfd, |
| 639 | (bfd_vma) linux_hash_table (info)->fixup_count, fixup_table); |
| 640 | fixup_table += 4; |
| 641 | |
| 642 | /* Fill in fixup table. */ |
| 643 | for (f = linux_hash_table (info)->fixup_list; f != NULL; f = f->next) |
| 644 | { |
| 645 | if (f->builtin) |
| 646 | continue; |
| 647 | |
| 648 | if (f->h->root.root.type != bfd_link_hash_defined |
| 649 | && f->h->root.root.type != bfd_link_hash_defweak) |
| 650 | { |
| 651 | (*_bfd_error_handler) |
| 652 | (_("Symbol %s not defined for fixups\n"), |
| 653 | f->h->root.root.root.string); |
| 654 | continue; |
| 655 | } |
| 656 | |
| 657 | is = f->h->root.root.u.def.section; |
| 658 | section_offset = is->output_section->vma + is->output_offset; |
| 659 | new_addr = f->h->root.root.u.def.value + section_offset; |
| 660 | |
| 661 | #ifdef LINUX_LINK_DEBUG |
| 662 | printf ("Fixup(%d) %s: %x %x\n",f->jump, f->h->root.root.string, |
| 663 | new_addr, f->value); |
| 664 | #endif |
| 665 | |
| 666 | if (f->jump) |
| 667 | { |
| 668 | /* Relative address */ |
| 669 | new_addr = new_addr - (f->value + 5); |
| 670 | bfd_put_32 (output_bfd, (bfd_vma) new_addr, fixup_table); |
| 671 | fixup_table += 4; |
| 672 | bfd_put_32 (output_bfd, f->value + 1, fixup_table); |
| 673 | fixup_table += 4; |
| 674 | } |
| 675 | else |
| 676 | { |
| 677 | bfd_put_32 (output_bfd, (bfd_vma) new_addr, fixup_table); |
| 678 | fixup_table += 4; |
| 679 | bfd_put_32 (output_bfd, f->value, fixup_table); |
| 680 | fixup_table += 4; |
| 681 | } |
| 682 | ++fixups_written; |
| 683 | } |
| 684 | |
| 685 | if (linux_hash_table (info)->local_builtins != 0) |
| 686 | { |
| 687 | /* Special marker so we know to switch to the other type of fixup */ |
| 688 | bfd_put_32 (output_bfd, (bfd_vma) 0, fixup_table); |
| 689 | fixup_table += 4; |
| 690 | bfd_put_32 (output_bfd, (bfd_vma) 0, fixup_table); |
| 691 | fixup_table += 4; |
| 692 | ++fixups_written; |
| 693 | for (f = linux_hash_table (info)->fixup_list; f != NULL; f = f->next) |
| 694 | { |
| 695 | if (! f->builtin) |
| 696 | continue; |
| 697 | |
| 698 | if (f->h->root.root.type != bfd_link_hash_defined |
| 699 | && f->h->root.root.type != bfd_link_hash_defweak) |
| 700 | { |
| 701 | (*_bfd_error_handler) |
| 702 | (_("Symbol %s not defined for fixups\n"), |
| 703 | f->h->root.root.root.string); |
| 704 | continue; |
| 705 | } |
| 706 | |
| 707 | is = f->h->root.root.u.def.section; |
| 708 | section_offset = is->output_section->vma + is->output_offset; |
| 709 | new_addr = f->h->root.root.u.def.value + section_offset; |
| 710 | |
| 711 | #ifdef LINUX_LINK_DEBUG |
| 712 | printf ("Fixup(B) %s: %x %x\n", f->h->root.root.string, |
| 713 | new_addr, f->value); |
| 714 | #endif |
| 715 | |
| 716 | bfd_put_32 (output_bfd, (bfd_vma) new_addr, fixup_table); |
| 717 | fixup_table += 4; |
| 718 | bfd_put_32 (output_bfd, f->value, fixup_table); |
| 719 | fixup_table += 4; |
| 720 | ++fixups_written; |
| 721 | } |
| 722 | } |
| 723 | |
| 724 | if (linux_hash_table (info)->fixup_count != fixups_written) |
| 725 | { |
| 726 | (*_bfd_error_handler) (_("Warning: fixup count mismatch\n")); |
| 727 | while (linux_hash_table (info)->fixup_count > fixups_written) |
| 728 | { |
| 729 | bfd_put_32 (output_bfd, (bfd_vma) 0, fixup_table); |
| 730 | fixup_table += 4; |
| 731 | bfd_put_32 (output_bfd, (bfd_vma) 0, fixup_table); |
| 732 | fixup_table += 4; |
| 733 | ++fixups_written; |
| 734 | } |
| 735 | } |
| 736 | |
| 737 | h = linux_link_hash_lookup (linux_hash_table (info), |
| 738 | "__BUILTIN_FIXUPS__", |
| 739 | FALSE, FALSE, FALSE); |
| 740 | |
| 741 | if (h != NULL |
| 742 | && (h->root.root.type == bfd_link_hash_defined |
| 743 | || h->root.root.type == bfd_link_hash_defweak)) |
| 744 | { |
| 745 | is = h->root.root.u.def.section; |
| 746 | section_offset = is->output_section->vma + is->output_offset; |
| 747 | new_addr = h->root.root.u.def.value + section_offset; |
| 748 | |
| 749 | #ifdef LINUX_LINK_DEBUG |
| 750 | printf ("Builtin fixup table at %x\n", new_addr); |
| 751 | #endif |
| 752 | |
| 753 | bfd_put_32 (output_bfd, (bfd_vma) new_addr, fixup_table); |
| 754 | } |
| 755 | else |
| 756 | bfd_put_32 (output_bfd, (bfd_vma) 0, fixup_table); |
| 757 | |
| 758 | if (bfd_seek (output_bfd, (file_ptr) (os->filepos + s->output_offset), |
| 759 | SEEK_SET) != 0) |
| 760 | return FALSE; |
| 761 | |
| 762 | if (bfd_bwrite ((PTR) s->contents, s->size, output_bfd) != s->size) |
| 763 | return FALSE; |
| 764 | |
| 765 | return TRUE; |
| 766 | } |
| 767 | |
| 768 | #define MY_bfd_link_hash_table_create linux_link_hash_table_create |
| 769 | #define MY_add_one_symbol linux_add_one_symbol |
| 770 | #define MY_finish_dynamic_link linux_finish_dynamic_link |
| 771 | |
| 772 | #define MY_zmagic_contiguous 1 |
| 773 | |
| 774 | #include "aout-target.h" |