| 1 | /* BFD support for handling relocation entries. |
| 2 | Copyright (C) 1990-1991 Free Software Foundation, Inc. |
| 3 | Written by Cygnus Support. |
| 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 2 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., 675 Mass Ave, Cambridge, MA 02139, USA. */ |
| 20 | |
| 21 | /* |
| 22 | SECTION |
| 23 | Relocations |
| 24 | |
| 25 | BFD maintains relocations in much the same was as it maintains |
| 26 | symbols; they are left alone until required, then read in |
| 27 | en-mass and traslated into an internal form. There is a common |
| 28 | routine <<bfd_perform_relocation>> which acts upon the |
| 29 | canonical form to to the actual fixup. |
| 30 | |
| 31 | Note that relocations are maintained on a per section basis, |
| 32 | whilst symbols are maintained on a per BFD basis. |
| 33 | |
| 34 | All a back end has to do to fit the BFD interface is to create |
| 35 | as many <<struct reloc_cache_entry>> as there are relocations |
| 36 | in a particuar section, and fill in the right bits: |
| 37 | |
| 38 | @menu |
| 39 | @* typedef arelent:: |
| 40 | @* howto manager:: |
| 41 | @end menu |
| 42 | |
| 43 | */ |
| 44 | #include "bfd.h" |
| 45 | #include "sysdep.h" |
| 46 | #include "libbfd.h" |
| 47 | #include "seclet.h" |
| 48 | /* |
| 49 | DOCDD |
| 50 | INODE |
| 51 | typedef arelent, howto manager, Relocations, Relocations |
| 52 | |
| 53 | SUBSECTION |
| 54 | typedef arelent |
| 55 | |
| 56 | This is the structure of a relocation entry: |
| 57 | |
| 58 | CODE_FRAGMENT |
| 59 | . |
| 60 | .typedef enum bfd_reloc_status |
| 61 | .{ |
| 62 | . {* No errors detected *} |
| 63 | . bfd_reloc_ok, |
| 64 | . |
| 65 | . {* The relocation was performed, but there was an overflow. *} |
| 66 | . bfd_reloc_overflow, |
| 67 | . |
| 68 | . {* The address to relocate was not within the section supplied*} |
| 69 | . bfd_reloc_outofrange, |
| 70 | . |
| 71 | . {* Used by special functions *} |
| 72 | . bfd_reloc_continue, |
| 73 | . |
| 74 | . {* Unused *} |
| 75 | . bfd_reloc_notsupported, |
| 76 | . |
| 77 | . {* Unsupported relocation size requested. *} |
| 78 | . bfd_reloc_other, |
| 79 | . |
| 80 | . {* The symbol to relocate against was undefined.*} |
| 81 | . bfd_reloc_undefined, |
| 82 | . |
| 83 | . {* The relocation was performed, but may not be ok - presently |
| 84 | . generated only when linking i960 coff files with i960 b.out |
| 85 | . symbols. *} |
| 86 | . bfd_reloc_dangerous |
| 87 | . } |
| 88 | . bfd_reloc_status_type; |
| 89 | . |
| 90 | . |
| 91 | .typedef struct reloc_cache_entry |
| 92 | .{ |
| 93 | . {* A pointer into the canonical table of pointers *} |
| 94 | . struct symbol_cache_entry **sym_ptr_ptr; |
| 95 | . |
| 96 | . {* offset in section *} |
| 97 | . rawdata_offset address; |
| 98 | . |
| 99 | . {* addend for relocation value *} |
| 100 | . bfd_vma addend; |
| 101 | . |
| 102 | . {* Pointer to how to perform the required relocation *} |
| 103 | . CONST struct reloc_howto_struct *howto; |
| 104 | . |
| 105 | .} arelent; |
| 106 | |
| 107 | */ |
| 108 | |
| 109 | /* |
| 110 | DESCRIPTION |
| 111 | |
| 112 | Here is a description of each of the fields within a relent: |
| 113 | |
| 114 | o sym_ptr_ptr |
| 115 | |
| 116 | The symbol table pointer points to a pointer to the symbol |
| 117 | associated with the relocation request. This would naturally |
| 118 | be the pointer into the table returned by the back end's |
| 119 | get_symtab action. @xref{Symbols}. The symbol is referenced |
| 120 | through a pointer to a pointer so that tools like the linker |
| 121 | can fix up all the symbols of the same name by modifying only |
| 122 | one pointer. The relocation routine looks in the symbol and |
| 123 | uses the base of the section the symbol is attached to and the |
| 124 | value of the symbol as the initial relocation offset. If the |
| 125 | symbol pointer is zero, then the section provided is looked up. |
| 126 | |
| 127 | o address |
| 128 | |
| 129 | The address field gives the offset in bytes from the base of |
| 130 | the section data which owns the relocation record to the first |
| 131 | byte of relocatable information. The actual data relocated |
| 132 | will be relative to this point - for example, a relocation |
| 133 | type which modifies the bottom two bytes of a four byte word |
| 134 | would not touch the first byte pointed to in a big endian |
| 135 | world. |
| 136 | |
| 137 | o addend |
| 138 | |
| 139 | The addend is a value provided by the back end to be added (!) |
| 140 | to the relocation offset. Its interpretation is dependent upon |
| 141 | the howto. For example, on the 68k the code: |
| 142 | |
| 143 | |
| 144 | | char foo[]; |
| 145 | | main() |
| 146 | | { |
| 147 | | return foo[0x12345678]; |
| 148 | | } |
| 149 | |
| 150 | Could be compiled into: |
| 151 | |
| 152 | | linkw fp,#-4 |
| 153 | | moveb @@#12345678,d0 |
| 154 | | extbl d0 |
| 155 | | unlk fp |
| 156 | | rts |
| 157 | |
| 158 | |
| 159 | This could create a reloc pointing to foo, but leave the |
| 160 | offset in the data (something like) |
| 161 | |
| 162 | |
| 163 | |RELOCATION RECORDS FOR [.text]: |
| 164 | |offset type value |
| 165 | |00000006 32 _foo |
| 166 | | |
| 167 | |00000000 4e56 fffc ; linkw fp,#-4 |
| 168 | |00000004 1039 1234 5678 ; moveb @@#12345678,d0 |
| 169 | |0000000a 49c0 ; extbl d0 |
| 170 | |0000000c 4e5e ; unlk fp |
| 171 | |0000000e 4e75 ; rts |
| 172 | |
| 173 | |
| 174 | Using coff and an 88k, some instructions don't have enough |
| 175 | space in them to represent the full address range, and |
| 176 | pointers have to be loaded in two parts. So you'd get something like: |
| 177 | |
| 178 | |
| 179 | | or.u r13,r0,hi16(_foo+0x12345678) |
| 180 | | ld.b r2,r13,lo16(_foo+0x12345678) |
| 181 | | jmp r1 |
| 182 | |
| 183 | |
| 184 | This whould create two relocs, both pointing to _foo, and with |
| 185 | 0x12340000 in their addend field. The data would consist of: |
| 186 | |
| 187 | |
| 188 | |RELOCATION RECORDS FOR [.text]: |
| 189 | |offset type value |
| 190 | |00000002 HVRT16 _foo+0x12340000 |
| 191 | |00000006 LVRT16 _foo+0x12340000 |
| 192 | |
| 193 | |00000000 5da05678 ; or.u r13,r0,0x5678 |
| 194 | |00000004 1c4d5678 ; ld.b r2,r13,0x5678 |
| 195 | |00000008 f400c001 ; jmp r1 |
| 196 | |
| 197 | |
| 198 | The relocation routine digs out the value from the data, adds |
| 199 | it to the addend to get the original offset and then adds the |
| 200 | value of _foo. Note that all 32 bits have to be kept around |
| 201 | somewhere, to cope with carry from bit 15 to bit 16. |
| 202 | |
| 203 | On further example is the sparc and the a.out format. The |
| 204 | sparc has a similar problem to the 88k, in that some |
| 205 | instructions don't have room for an entire offset, but on the |
| 206 | sparc the parts are created odd sized lumps. The designers of |
| 207 | the a.out format chose not to use the data within the section |
| 208 | for storing part of the offset; all the offset is kept within |
| 209 | the reloc. Any thing in the data should be ignored. |
| 210 | |
| 211 | | save %sp,-112,%sp |
| 212 | | sethi %hi(_foo+0x12345678),%g2 |
| 213 | | ldsb [%g2+%lo(_foo+0x12345678)],%i0 |
| 214 | | ret |
| 215 | | restore |
| 216 | |
| 217 | Both relocs contains a pointer to foo, and the offsets would |
| 218 | contain junk. |
| 219 | |
| 220 | |
| 221 | |RELOCATION RECORDS FOR [.text]: |
| 222 | |offset type value |
| 223 | |00000004 HI22 _foo+0x12345678 |
| 224 | |00000008 LO10 _foo+0x12345678 |
| 225 | |
| 226 | |00000000 9de3bf90 ; save %sp,-112,%sp |
| 227 | |00000004 05000000 ; sethi %hi(_foo+0),%g2 |
| 228 | |00000008 f048a000 ; ldsb [%g2+%lo(_foo+0)],%i0 |
| 229 | |0000000c 81c7e008 ; ret |
| 230 | |00000010 81e80000 ; restore |
| 231 | |
| 232 | |
| 233 | o howto |
| 234 | |
| 235 | The howto field can be imagined as a |
| 236 | relocation instruction. It is a pointer to a struct which |
| 237 | contains information on what to do with all the other |
| 238 | information in the reloc record and data section. A back end |
| 239 | would normally have a relocation instruction set and turn |
| 240 | relocations into pointers to the correct structure on input - |
| 241 | but it would be possible to create each howto field on demand. |
| 242 | |
| 243 | */ |
| 244 | |
| 245 | |
| 246 | /* |
| 247 | SUBSUBSECTION |
| 248 | <<reloc_howto_type>> |
| 249 | |
| 250 | The <<reloc_howto_type>> is a structure which contains all the |
| 251 | information that BFD needs to know to tie up a back end's data. |
| 252 | |
| 253 | CODE_FRAGMENT |
| 254 | .struct symbol_cache_entry; {* Forward declaration *} |
| 255 | . |
| 256 | .typedef CONST struct reloc_howto_struct |
| 257 | .{ |
| 258 | . {* The type field has mainly a documetary use - the back end can |
| 259 | . to what it wants with it, though the normally the back end's |
| 260 | . external idea of what a reloc number would be would be stored |
| 261 | . in this field. For example, the a PC relative word relocation |
| 262 | . in a coff environment would have the type 023 - because that's |
| 263 | . what the outside world calls a R_PCRWORD reloc. *} |
| 264 | . unsigned int type; |
| 265 | . |
| 266 | . {* The value the final relocation is shifted right by. This drops |
| 267 | . unwanted data from the relocation. *} |
| 268 | . unsigned int rightshift; |
| 269 | . |
| 270 | . {* The size of the item to be relocated - 0, is one byte, 1 is 2 |
| 271 | . bytes, 3 is four bytes. A -ve value indicates that the |
| 272 | . result is to be subtracted from the data*} |
| 273 | . int size; |
| 274 | . |
| 275 | . {* Now obsolete *} |
| 276 | . unsigned int bitsize; |
| 277 | . |
| 278 | . {* Notes that the relocation is relative to the location in the |
| 279 | . data section of the addend. The relocation function will |
| 280 | . subtract from the relocation value the address of the location |
| 281 | . being relocated. *} |
| 282 | . boolean pc_relative; |
| 283 | . |
| 284 | . {* Now obsolete *} |
| 285 | . unsigned int bitpos; |
| 286 | . |
| 287 | . {* Now obsolete *} |
| 288 | . boolean absolute; |
| 289 | . |
| 290 | . {* Causes the relocation routine to return an error if overflow |
| 291 | . is detected when relocating. *} |
| 292 | . boolean complain_on_overflow; |
| 293 | . |
| 294 | . {* If this field is non null, then the supplied function is |
| 295 | . called rather than the normal function. This allows really |
| 296 | . strange relocation methods to be accomodated (eg, i960 callj |
| 297 | . instructions). *} |
| 298 | . bfd_reloc_status_type (*special_function) |
| 299 | . PARAMS ((bfd *abfd, |
| 300 | . arelent *reloc_entry, |
| 301 | . struct symbol_cache_entry *symbol, |
| 302 | . PTR data, |
| 303 | . asection *input_section, |
| 304 | . bfd *output_bfd)); |
| 305 | . |
| 306 | . {* The textual name of the relocation type. *} |
| 307 | . char *name; |
| 308 | . |
| 309 | . {* When performing a partial link, some formats must modify the |
| 310 | . relocations rather than the data - this flag signals this.*} |
| 311 | . boolean partial_inplace; |
| 312 | . |
| 313 | . {* The src_mask is used to select what parts of the read in data |
| 314 | . are to be used in the relocation sum. Eg, if this was an 8 bit |
| 315 | . bit of data which we read and relocated, this would be |
| 316 | . 0x000000ff. When we have relocs which have an addend, such as |
| 317 | . sun4 extended relocs, the value in the offset part of a |
| 318 | . relocating field is garbage so we never use it. In this case |
| 319 | . the mask would be 0x00000000. *} |
| 320 | . bfd_word src_mask; |
| 321 | . |
| 322 | . {* The dst_mask is what parts of the instruction are replaced |
| 323 | . into the instruction. In most cases src_mask == dst_mask, |
| 324 | . except in the above special case, where dst_mask would be |
| 325 | . 0x000000ff, and src_mask would be 0x00000000. *} |
| 326 | . bfd_word dst_mask; |
| 327 | . |
| 328 | . {* When some formats create PC relative instructions, they leave |
| 329 | . the value of the pc of the place being relocated in the offset |
| 330 | . slot of the instruction, so that a PC relative relocation can |
| 331 | . be made just by adding in an ordinary offset (eg sun3 a.out). |
| 332 | . Some formats leave the displacement part of an instruction |
| 333 | . empty (eg m88k bcs), this flag signals the fact.*} |
| 334 | . boolean pcrel_offset; |
| 335 | . |
| 336 | .} reloc_howto_type; |
| 337 | |
| 338 | */ |
| 339 | |
| 340 | /* |
| 341 | FUNCTION |
| 342 | the HOWTO macro |
| 343 | |
| 344 | DESCRIPTION |
| 345 | The HOWTO define is horrible and will go away. |
| 346 | |
| 347 | |
| 348 | .#define HOWTO(C, R,S,B, P, BI, ABS, O, SF, NAME, INPLACE, MASKSRC, MASKDST, PC) \ |
| 349 | . {(unsigned)C,R,S,B, P, BI, ABS,O,SF,NAME,INPLACE,MASKSRC,MASKDST,PC} |
| 350 | |
| 351 | DESCRIPTION |
| 352 | And will be replaced with the totally magic way. But for the |
| 353 | moment, we are compatible, so do it this way.. |
| 354 | |
| 355 | |
| 356 | .#define NEWHOWTO( FUNCTION, NAME,SIZE,REL,IN) HOWTO(0,0,SIZE,0,REL,0,false,false,FUNCTION, NAME,false,0,0,IN) |
| 357 | . |
| 358 | DESCRIPTION |
| 359 | Helper routine to turn a symbol into a relocation value. |
| 360 | |
| 361 | .#define HOWTO_PREPARE(relocation, symbol) \ |
| 362 | . { \ |
| 363 | . if (symbol != (asymbol *)NULL) { \ |
| 364 | . if (symbol->section == &bfd_com_section) { \ |
| 365 | . relocation = 0; \ |
| 366 | . } \ |
| 367 | . else { \ |
| 368 | . relocation = symbol->value; \ |
| 369 | . } \ |
| 370 | . } \ |
| 371 | .} |
| 372 | |
| 373 | */ |
| 374 | |
| 375 | /* |
| 376 | TYPEDEF |
| 377 | reloc_chain |
| 378 | |
| 379 | DESCRIPTION |
| 380 | |
| 381 | How relocs are tied together |
| 382 | |
| 383 | .typedef unsigned char bfd_byte; |
| 384 | . |
| 385 | .typedef struct relent_chain { |
| 386 | . arelent relent; |
| 387 | . struct relent_chain *next; |
| 388 | .} arelent_chain; |
| 389 | |
| 390 | */ |
| 391 | |
| 392 | |
| 393 | |
| 394 | /* |
| 395 | FUNCTION |
| 396 | bfd_perform_relocation |
| 397 | |
| 398 | SYNOPSIS |
| 399 | bfd_reloc_status_type |
| 400 | bfd_perform_relocation |
| 401 | (bfd * abfd, |
| 402 | arelent *reloc_entry, |
| 403 | PTR data, |
| 404 | asection *input_section, |
| 405 | bfd *output_bfd); |
| 406 | |
| 407 | DESCRIPTION |
| 408 | If an output_bfd is supplied to this function the generated |
| 409 | image will be relocatable, the relocations are copied to the |
| 410 | output file after they have been changed to reflect the new |
| 411 | state of the world. There are two ways of reflecting the |
| 412 | results of partial linkage in an output file; by modifying the |
| 413 | output data in place, and by modifying the relocation record. |
| 414 | Some native formats (eg basic a.out and basic coff) have no |
| 415 | way of specifying an addend in the relocation type, so the |
| 416 | addend has to go in the output data. This is no big deal |
| 417 | since in these formats the output data slot will always be big |
| 418 | enough for the addend. Complex reloc types with addends were |
| 419 | invented to solve just this problem. |
| 420 | |
| 421 | */ |
| 422 | |
| 423 | |
| 424 | bfd_reloc_status_type |
| 425 | DEFUN(bfd_perform_relocation,(abfd, |
| 426 | reloc_entry, |
| 427 | data, |
| 428 | input_section, |
| 429 | output_bfd), |
| 430 | bfd *abfd AND |
| 431 | arelent *reloc_entry AND |
| 432 | PTR data AND |
| 433 | asection *input_section AND |
| 434 | bfd *output_bfd) |
| 435 | { |
| 436 | bfd_vma relocation; |
| 437 | bfd_reloc_status_type flag = bfd_reloc_ok; |
| 438 | bfd_vma addr = reloc_entry->address ; |
| 439 | bfd_vma output_base = 0; |
| 440 | reloc_howto_type *howto = reloc_entry->howto; |
| 441 | asection *reloc_target_output_section ; |
| 442 | |
| 443 | asymbol *symbol; |
| 444 | |
| 445 | symbol = *( reloc_entry->sym_ptr_ptr); |
| 446 | if ((symbol->section == &bfd_abs_section) |
| 447 | && output_bfd != (bfd *)NULL) |
| 448 | { |
| 449 | reloc_entry->address += input_section->output_offset; |
| 450 | |
| 451 | return bfd_reloc_ok; |
| 452 | |
| 453 | } |
| 454 | |
| 455 | if ((symbol->section == &bfd_und_section) && output_bfd == (bfd *)NULL) { |
| 456 | flag = bfd_reloc_undefined; |
| 457 | } |
| 458 | |
| 459 | if (howto->special_function) { |
| 460 | bfd_reloc_status_type cont; |
| 461 | cont = howto->special_function(abfd, |
| 462 | reloc_entry, |
| 463 | symbol, |
| 464 | data, |
| 465 | input_section, |
| 466 | output_bfd); |
| 467 | if (cont != bfd_reloc_continue) return cont; |
| 468 | } |
| 469 | |
| 470 | /* |
| 471 | Work out which section the relocation is targetted at and the |
| 472 | initial relocation command value. |
| 473 | */ |
| 474 | |
| 475 | |
| 476 | if (symbol->section == &bfd_com_section) { |
| 477 | relocation = 0; |
| 478 | } |
| 479 | else { |
| 480 | relocation = symbol->value; |
| 481 | } |
| 482 | |
| 483 | |
| 484 | reloc_target_output_section = symbol->section->output_section; |
| 485 | |
| 486 | if (output_bfd && howto->partial_inplace==false) { |
| 487 | output_base = 0; |
| 488 | } |
| 489 | else { |
| 490 | output_base = reloc_target_output_section->vma; |
| 491 | |
| 492 | } |
| 493 | |
| 494 | relocation += output_base + symbol->section->output_offset; |
| 495 | |
| 496 | |
| 497 | relocation += reloc_entry->addend ; |
| 498 | |
| 499 | |
| 500 | if(reloc_entry->address > input_section->_cooked_size) |
| 501 | { |
| 502 | return bfd_reloc_outofrange; |
| 503 | } |
| 504 | |
| 505 | |
| 506 | if (howto->pc_relative == true) |
| 507 | { |
| 508 | /* |
| 509 | Anything which started out as pc relative should end up that |
| 510 | way too. |
| 511 | |
| 512 | There are two ways we can see a pcrel instruction. Sometimes |
| 513 | the pcrel displacement has been partially calculated, it |
| 514 | includes the distance from the start of the section to the |
| 515 | instruction in it (eg sun3), and sometimes the field is |
| 516 | totally blank - eg m88kbcs. |
| 517 | */ |
| 518 | |
| 519 | |
| 520 | relocation -= |
| 521 | input_section->output_section->vma + input_section->output_offset; |
| 522 | |
| 523 | if (howto->pcrel_offset == true) { |
| 524 | relocation -= reloc_entry->address; |
| 525 | } |
| 526 | |
| 527 | } |
| 528 | |
| 529 | if (output_bfd!= (bfd *)NULL) |
| 530 | { |
| 531 | if ( howto->partial_inplace == false) |
| 532 | { |
| 533 | /* |
| 534 | This is a partial relocation, and we want to apply the relocation |
| 535 | to the reloc entry rather than the raw data. Modify the reloc |
| 536 | inplace to reflect what we now know. |
| 537 | */ |
| 538 | reloc_entry->addend = relocation ; |
| 539 | reloc_entry->address += input_section->output_offset; |
| 540 | return flag; |
| 541 | } |
| 542 | else |
| 543 | { |
| 544 | /* This is a partial relocation, but inplace, so modify the |
| 545 | reloc record a bit. |
| 546 | |
| 547 | If we've relocated with a symbol with a section, change |
| 548 | into a ref to the section belonging to the symbol |
| 549 | */ |
| 550 | |
| 551 | reloc_entry->address += input_section->output_offset; |
| 552 | |
| 553 | if (abfd->xvec->flavour == bfd_target_coff_flavour) |
| 554 | { |
| 555 | relocation -= reloc_entry->addend; |
| 556 | reloc_entry->addend = 0; |
| 557 | } |
| 558 | else |
| 559 | { |
| 560 | reloc_entry->addend = relocation ; |
| 561 | } |
| 562 | } |
| 563 | } |
| 564 | else |
| 565 | { |
| 566 | reloc_entry->addend = 0; |
| 567 | } |
| 568 | |
| 569 | |
| 570 | /* |
| 571 | Either we are relocating all the way, or we don't want to apply |
| 572 | the relocation to the reloc entry (probably because there isn't |
| 573 | any room in the output format to describe addends to relocs) |
| 574 | */ |
| 575 | relocation >>= howto->rightshift; |
| 576 | |
| 577 | /* Shift everything up to where it's going to be used */ |
| 578 | |
| 579 | relocation <<= howto->bitpos; |
| 580 | |
| 581 | /* Wait for the day when all have the mask in them */ |
| 582 | |
| 583 | /* What we do: |
| 584 | i instruction to be left alone |
| 585 | o offset within instruction |
| 586 | r relocation offset to apply |
| 587 | S src mask |
| 588 | D dst mask |
| 589 | N ~dst mask |
| 590 | A part 1 |
| 591 | B part 2 |
| 592 | R result |
| 593 | |
| 594 | Do this: |
| 595 | i i i i i o o o o o from bfd_get<size> |
| 596 | and S S S S S to get the size offset we want |
| 597 | + r r r r r r r r r r to get the final value to place |
| 598 | and D D D D D to chop to right size |
| 599 | ----------------------- |
| 600 | A A A A A |
| 601 | And this: |
| 602 | ... i i i i i o o o o o from bfd_get<size> |
| 603 | and N N N N N get instruction |
| 604 | ----------------------- |
| 605 | ... B B B B B |
| 606 | |
| 607 | And then: |
| 608 | B B B B B |
| 609 | or A A A A A |
| 610 | ----------------------- |
| 611 | R R R R R R R R R R put into bfd_put<size> |
| 612 | */ |
| 613 | |
| 614 | #define DOIT(x) \ |
| 615 | x = ( (x & ~howto->dst_mask) | (((x & howto->src_mask) + relocation) & howto->dst_mask)) |
| 616 | |
| 617 | switch (howto->size) |
| 618 | { |
| 619 | case 0: |
| 620 | { |
| 621 | char x = bfd_get_8(abfd, (char *)data + addr); |
| 622 | DOIT(x); |
| 623 | bfd_put_8(abfd,x, (unsigned char *) data + addr); |
| 624 | } |
| 625 | break; |
| 626 | |
| 627 | case 1: |
| 628 | { |
| 629 | short x = bfd_get_16(abfd, (bfd_byte *)data + addr); |
| 630 | DOIT(x); |
| 631 | bfd_put_16(abfd, x, (unsigned char *)data + addr); |
| 632 | } |
| 633 | break; |
| 634 | case 2: |
| 635 | { |
| 636 | long x = bfd_get_32(abfd, (bfd_byte *) data + addr); |
| 637 | DOIT(x); |
| 638 | bfd_put_32(abfd,x, (bfd_byte *)data + addr); |
| 639 | } |
| 640 | break; |
| 641 | case -2: |
| 642 | { |
| 643 | long x = bfd_get_32(abfd, (bfd_byte *) data + addr); |
| 644 | relocation = -relocation; |
| 645 | DOIT(x); |
| 646 | bfd_put_32(abfd,x, (bfd_byte *)data + addr); |
| 647 | } |
| 648 | break; |
| 649 | |
| 650 | case 3: |
| 651 | |
| 652 | /* Do nothing */ |
| 653 | break; |
| 654 | default: |
| 655 | return bfd_reloc_other; |
| 656 | } |
| 657 | |
| 658 | return flag; |
| 659 | } |
| 660 | |
| 661 | |
| 662 | |
| 663 | /* |
| 664 | DOCDD |
| 665 | INODE |
| 666 | howto manager, , typedef arelent, Relocations |
| 667 | |
| 668 | SECTION |
| 669 | The howto manager |
| 670 | |
| 671 | When an application wants to create a relocation, but doesn't |
| 672 | know what the target machine might call it, it can find out by |
| 673 | using this bit of code. |
| 674 | |
| 675 | */ |
| 676 | |
| 677 | /* |
| 678 | TYPEDEF |
| 679 | bfd_reloc_code_type |
| 680 | |
| 681 | DESCRIPTION |
| 682 | The insides of a reloc code |
| 683 | |
| 684 | CODE_FRAGMENT |
| 685 | . |
| 686 | .typedef enum bfd_reloc_code_real |
| 687 | . |
| 688 | .{ |
| 689 | . {* 16 bits wide, simple reloc *} |
| 690 | . BFD_RELOC_16, |
| 691 | . |
| 692 | . {* 8 bits wide, but used to form an address like 0xffnn *} |
| 693 | . BFD_RELOC_8_FFnn, |
| 694 | . |
| 695 | . {* 8 bits wide, simple *} |
| 696 | . BFD_RELOC_8, |
| 697 | . |
| 698 | . {* 8 bits wide, pc relative *} |
| 699 | . BFD_RELOC_8_PCREL, |
| 700 | . |
| 701 | . {* The type of reloc used to build a contructor table - at the |
| 702 | . moment probably a 32 bit wide abs address, but the cpu can |
| 703 | . choose. *} |
| 704 | . |
| 705 | . BFD_RELOC_CTOR, |
| 706 | . |
| 707 | . {* 32 bits wide, simple reloc *} |
| 708 | . BFD_RELOC_32, |
| 709 | . {* 32 bits, PC-relative *} |
| 710 | . BFD_RELOC_32_PCREL, |
| 711 | . |
| 712 | . {* High 22 bits of 32-bit value; simple reloc. *} |
| 713 | . BFD_RELOC_HI22, |
| 714 | . {* Low 10 bits. *} |
| 715 | . BFD_RELOC_LO10, |
| 716 | . |
| 717 | . {* Reloc types used for i960/b.out. *} |
| 718 | . BFD_RELOC_24_PCREL, |
| 719 | . BFD_RELOC_I960_CALLJ, |
| 720 | . |
| 721 | . BFD_RELOC_16_PCREL, |
| 722 | . {* 32-bit pc-relative, shifted right 2 bits (i.e., 30-bit |
| 723 | . word displacement, e.g. for SPARC) *} |
| 724 | . BFD_RELOC_32_PCREL_S2, |
| 725 | . |
| 726 | . {* now for the sparc/elf codes *} |
| 727 | . BFD_RELOC_NONE, {* actually used *} |
| 728 | . BFD_RELOC_SPARC_WDISP22, |
| 729 | . BFD_RELOC_SPARC22, |
| 730 | . BFD_RELOC_SPARC13, |
| 731 | . BFD_RELOC_SPARC_BASE13, |
| 732 | . BFD_RELOC_SPARC_GOT10, |
| 733 | . BFD_RELOC_SPARC_GOT13, |
| 734 | . BFD_RELOC_SPARC_GOT22, |
| 735 | . BFD_RELOC_SPARC_PC10, |
| 736 | . BFD_RELOC_SPARC_PC22, |
| 737 | . BFD_RELOC_SPARC_WPLT30, |
| 738 | . BFD_RELOC_SPARC_COPY, |
| 739 | . BFD_RELOC_SPARC_GLOB_DAT, |
| 740 | . BFD_RELOC_SPARC_JMP_SLOT, |
| 741 | . BFD_RELOC_SPARC_RELATIVE, |
| 742 | . BFD_RELOC_SPARC_UA32, |
| 743 | . |
| 744 | . {* this one is a.out specific? *} |
| 745 | . BFD_RELOC_SPARC_BASE22, |
| 746 | . |
| 747 | . {* this must be the highest numeric value *} |
| 748 | . BFD_RELOC_UNUSED |
| 749 | . } bfd_reloc_code_real_type; |
| 750 | */ |
| 751 | |
| 752 | |
| 753 | |
| 754 | /* |
| 755 | SECTION |
| 756 | bfd_reloc_type_lookup |
| 757 | |
| 758 | SYNOPSIS |
| 759 | CONST struct reloc_howto_struct * |
| 760 | bfd_reloc_type_lookup (bfd *abfd, bfd_reloc_code_real_type code); |
| 761 | |
| 762 | DESCRIPTION |
| 763 | This routine returns a pointer to a howto struct which when |
| 764 | invoked, will perform the supplied relocation on data from the |
| 765 | architecture noted. |
| 766 | |
| 767 | */ |
| 768 | |
| 769 | |
| 770 | CONST struct reloc_howto_struct * |
| 771 | DEFUN(bfd_reloc_type_lookup,(abfd, code), |
| 772 | bfd *abfd AND |
| 773 | bfd_reloc_code_real_type code) |
| 774 | { |
| 775 | return BFD_SEND (abfd, reloc_type_lookup, (abfd, code)); |
| 776 | } |
| 777 | |
| 778 | static reloc_howto_type bfd_howto_32 = |
| 779 | HOWTO(0, 00,2,32,false,0,false,true,0,"VRT32", false,0xffffffff,0xffffffff,true); |
| 780 | |
| 781 | |
| 782 | /* |
| 783 | INTERNAL_FUNCTION |
| 784 | bfd_default_reloc_type_lookup |
| 785 | |
| 786 | SYNOPSIS |
| 787 | CONST struct reloc_howto_struct *bfd_default_reloc_type_lookup |
| 788 | (CONST struct bfd_arch_info *, |
| 789 | bfd_reloc_code_real_type code); |
| 790 | |
| 791 | DESCRIPTION |
| 792 | Provides a default relocation lookuperer for any architectue |
| 793 | |
| 794 | |
| 795 | */ |
| 796 | CONST struct reloc_howto_struct * |
| 797 | DEFUN(bfd_default_reloc_type_lookup,(arch, code), |
| 798 | CONST struct bfd_arch_info *arch AND |
| 799 | bfd_reloc_code_real_type code) |
| 800 | { |
| 801 | switch (code) |
| 802 | { |
| 803 | case BFD_RELOC_CTOR: |
| 804 | /* The type of reloc used in a ctor, which will be as wide as the |
| 805 | address - so either a 64, 32, or 16 bitter.. */ |
| 806 | switch (arch->bits_per_address) { |
| 807 | case 64: |
| 808 | BFD_FAIL(); |
| 809 | case 32: |
| 810 | return &bfd_howto_32; |
| 811 | case 16: |
| 812 | BFD_FAIL(); |
| 813 | default: |
| 814 | BFD_FAIL(); |
| 815 | } |
| 816 | default: |
| 817 | BFD_FAIL(); |
| 818 | } |
| 819 | return (CONST struct reloc_howto_struct *)NULL; |
| 820 | } |
| 821 | |
| 822 | |
| 823 | /* |
| 824 | INTERNAL_FUNCTION |
| 825 | bfd_generic_relax_section |
| 826 | |
| 827 | SYNOPSIS |
| 828 | boolean bfd_generic_relax_section |
| 829 | (bfd *abfd, |
| 830 | asection *section, |
| 831 | asymbol **symbols); |
| 832 | |
| 833 | DESCRIPTION |
| 834 | Provides default handling for relaxing for back ends which |
| 835 | don't do relaxing -- i.e., does nothing. |
| 836 | */ |
| 837 | |
| 838 | boolean |
| 839 | DEFUN(bfd_generic_relax_section,(abfd, section, symbols), |
| 840 | bfd *abfd AND |
| 841 | asection *section AND |
| 842 | asymbol **symbols) |
| 843 | { |
| 844 | |
| 845 | return false; |
| 846 | |
| 847 | } |
| 848 | |
| 849 | |
| 850 | /* |
| 851 | INTERNAL_FUNCTION |
| 852 | bfd_generic_get_relocated_section_contents |
| 853 | |
| 854 | SYNOPSIS |
| 855 | bfd_byte * |
| 856 | bfd_generic_get_relocated_section_contents(bfd *abfd, |
| 857 | struct bfd_seclet_struct *seclet, |
| 858 | bfd_byte *data) |
| 859 | |
| 860 | DESCRIPTION |
| 861 | Provides default handling of relocation effort for back ends |
| 862 | which can't be bothered to do it efficiently. |
| 863 | |
| 864 | */ |
| 865 | |
| 866 | bfd_byte * |
| 867 | DEFUN(bfd_generic_get_relocated_section_contents,(abfd, seclet, data), |
| 868 | bfd *abfd AND |
| 869 | struct bfd_seclet_struct *seclet AND |
| 870 | bfd_byte *data) |
| 871 | { |
| 872 | extern bfd_error_vector_type bfd_error_vector; |
| 873 | |
| 874 | /* Get enough memory to hold the stuff */ |
| 875 | bfd *input_bfd = seclet->u.indirect.section->owner; |
| 876 | asection *input_section = seclet->u.indirect.section; |
| 877 | |
| 878 | |
| 879 | |
| 880 | bfd_size_type reloc_size = bfd_get_reloc_upper_bound(input_bfd, |
| 881 | input_section); |
| 882 | arelent **reloc_vector = (arelent **) alloca(reloc_size); |
| 883 | |
| 884 | /* read in the section */ |
| 885 | bfd_get_section_contents(input_bfd, |
| 886 | input_section, |
| 887 | data, |
| 888 | 0, |
| 889 | input_section->_raw_size); |
| 890 | |
| 891 | /* We're not relaxing the section, so just copy the size info */ |
| 892 | input_section->_cooked_size = input_section->_raw_size; |
| 893 | input_section->reloc_done = true; |
| 894 | |
| 895 | |
| 896 | if (bfd_canonicalize_reloc(input_bfd, |
| 897 | input_section, |
| 898 | reloc_vector, |
| 899 | seclet->u.indirect.symbols) ) |
| 900 | { |
| 901 | arelent **parent; |
| 902 | for (parent = reloc_vector; * parent != (arelent *)NULL; |
| 903 | parent++) |
| 904 | { |
| 905 | bfd_reloc_status_type r= |
| 906 | bfd_perform_relocation(input_bfd, |
| 907 | *parent, |
| 908 | data, |
| 909 | input_section, 0); |
| 910 | |
| 911 | |
| 912 | if (r != bfd_reloc_ok) |
| 913 | { |
| 914 | switch (r) |
| 915 | { |
| 916 | case bfd_reloc_undefined: |
| 917 | bfd_error_vector.undefined_symbol(*parent, seclet); |
| 918 | break; |
| 919 | case bfd_reloc_dangerous: |
| 920 | bfd_error_vector.reloc_dangerous(*parent, seclet); |
| 921 | break; |
| 922 | case bfd_reloc_outofrange: |
| 923 | case bfd_reloc_overflow: |
| 924 | bfd_error_vector.reloc_value_truncated(*parent, seclet); |
| 925 | break; |
| 926 | default: |
| 927 | abort(); |
| 928 | break; |
| 929 | } |
| 930 | |
| 931 | } |
| 932 | } |
| 933 | } |
| 934 | |
| 935 | |
| 936 | return data; |
| 937 | |
| 938 | |
| 939 | } |
| 940 | |