| 1 | /* Dump Emacs in macho format. |
| 2 | Copyright (C) 1990, 1993 Free Software Foundation, Inc. |
| 3 | Written by Bradley Taylor (btaylor@next.com). |
| 4 | |
| 5 | This file is part of GNU Emacs. |
| 6 | |
| 7 | GNU Emacs 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, or (at your option) |
| 10 | any later version. |
| 11 | |
| 12 | GNU Emacs 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 GNU Emacs; see the file COPYING. If not, write to |
| 19 | the Free Software Foundation, Inc., 59 Temple Place - Suite 330, |
| 20 | Boston, MA 02111-1307, USA. */ |
| 21 | |
| 22 | |
| 23 | #undef __STRICT_BSD__ |
| 24 | |
| 25 | #include <stdio.h> |
| 26 | #include <stdlib.h> |
| 27 | #include <stdarg.h> |
| 28 | #include <mach/mach.h> |
| 29 | #include <mach-o/loader.h> |
| 30 | #include <mach-o/reloc.h> |
| 31 | #include <sys/file.h> |
| 32 | #include <sys/stat.h> |
| 33 | #include <unistd.h> |
| 34 | /* Instead of unistd.h, this used to include libc.h. |
| 35 | "Nelson H. F. Beebe" <beebe@math.utah.edu> says that doesn't work |
| 36 | in system version 3.3. */ |
| 37 | |
| 38 | |
| 39 | int malloc_cookie; |
| 40 | |
| 41 | /* |
| 42 | * Kludge: we don't expect any program data beyond VM_HIGHDATA |
| 43 | * What is really needed is a way to find out from malloc() which |
| 44 | * pages it vm_allocated and write only those out into the data segment. |
| 45 | * |
| 46 | * This kludge may break when we stop using fixed virtual address |
| 47 | * shared libraries. Actually, emacs will probably continue working, but be |
| 48 | * much larger on disk than it needs to be (because non-malloced data will |
| 49 | * be in the file). |
| 50 | */ |
| 51 | static const unsigned VM_HIGHDATA = 0x2000000; |
| 52 | |
| 53 | typedef struct region_t { |
| 54 | vm_address_t address; |
| 55 | vm_size_t size; |
| 56 | vm_prot_t protection; |
| 57 | vm_prot_t max_protection; |
| 58 | vm_inherit_t inheritance; |
| 59 | boolean_t shared; |
| 60 | port_t object_name; |
| 61 | vm_offset_t offset; |
| 62 | } region_t; |
| 63 | |
| 64 | |
| 65 | static void |
| 66 | grow( |
| 67 | struct load_command ***the_commands, |
| 68 | unsigned *the_commands_len |
| 69 | ) |
| 70 | { |
| 71 | if (*the_commands == NULL) { |
| 72 | *the_commands_len = 1; |
| 73 | *the_commands = malloc(sizeof(*the_commands)); |
| 74 | } else { |
| 75 | (*the_commands_len)++; |
| 76 | *the_commands = realloc(*the_commands, |
| 77 | (*the_commands_len * |
| 78 | sizeof(**the_commands))); |
| 79 | } |
| 80 | } |
| 81 | |
| 82 | |
| 83 | static void |
| 84 | save_command( |
| 85 | struct load_command *command, |
| 86 | struct load_command ***the_commands, |
| 87 | unsigned *the_commands_len |
| 88 | ) |
| 89 | { |
| 90 | struct load_command **tmp; |
| 91 | |
| 92 | grow(the_commands, the_commands_len); |
| 93 | tmp = &(*the_commands)[*the_commands_len - 1]; |
| 94 | *tmp = malloc(command->cmdsize); |
| 95 | bcopy(command, *tmp, command->cmdsize); |
| 96 | } |
| 97 | |
| 98 | static void |
| 99 | fatal_unexec(char *format, ...) |
| 100 | { |
| 101 | va_list ap; |
| 102 | |
| 103 | va_start(ap, format); |
| 104 | fprintf(stderr, "unexec: "); |
| 105 | vfprintf(stderr, format, ap); |
| 106 | fprintf(stderr, "\n"); |
| 107 | va_end(ap); |
| 108 | } |
| 109 | |
| 110 | static int |
| 111 | read_macho( |
| 112 | int fd, |
| 113 | struct mach_header *the_header, |
| 114 | struct load_command ***the_commands, |
| 115 | unsigned *the_commands_len |
| 116 | ) |
| 117 | { |
| 118 | struct load_command command; |
| 119 | struct load_command *buf; |
| 120 | int i; |
| 121 | int size; |
| 122 | |
| 123 | if (read(fd, the_header, sizeof(*the_header)) != sizeof(*the_header)) { |
| 124 | fatal_unexec("cannot read macho header"); |
| 125 | return (0); |
| 126 | } |
| 127 | for (i = 0; i < the_header->ncmds; i++) { |
| 128 | if (read(fd, &command, sizeof(struct load_command)) != |
| 129 | sizeof(struct load_command)) { |
| 130 | fatal_unexec("cannot read macho load command header"); |
| 131 | return (0); |
| 132 | } |
| 133 | size = command.cmdsize - sizeof(struct load_command); |
| 134 | if (size < 0) { |
| 135 | fatal_unexec("bogus load command size"); |
| 136 | return (0); |
| 137 | } |
| 138 | buf = malloc(command.cmdsize); |
| 139 | buf->cmd = command.cmd; |
| 140 | buf->cmdsize = command.cmdsize; |
| 141 | if (read(fd, ((char *)buf + |
| 142 | sizeof(struct load_command)), |
| 143 | size) != size) { |
| 144 | fatal_unexec("cannot read load command data"); |
| 145 | return (0); |
| 146 | } |
| 147 | save_command(buf, the_commands, the_commands_len); |
| 148 | } |
| 149 | return (1); |
| 150 | } |
| 151 | |
| 152 | static int |
| 153 | filldatagap( |
| 154 | vm_address_t start_address, |
| 155 | vm_size_t *size, |
| 156 | vm_address_t end_address |
| 157 | ) |
| 158 | { |
| 159 | vm_address_t address; |
| 160 | vm_size_t gapsize; |
| 161 | |
| 162 | address = (start_address + *size); |
| 163 | gapsize = end_address - address; |
| 164 | *size += gapsize; |
| 165 | if (vm_allocate(task_self(), &address, gapsize, |
| 166 | FALSE) != KERN_SUCCESS) { |
| 167 | fatal_unexec("cannot vm_allocate"); |
| 168 | return (0); |
| 169 | } |
| 170 | return (1); |
| 171 | } |
| 172 | |
| 173 | static int |
| 174 | get_data_region( |
| 175 | vm_address_t *address, |
| 176 | vm_size_t *size |
| 177 | ) |
| 178 | { |
| 179 | region_t region; |
| 180 | kern_return_t ret; |
| 181 | struct section *sect; |
| 182 | |
| 183 | sect = (struct section *) getsectbyname(SEG_DATA, SECT_DATA); |
| 184 | region.address = 0; |
| 185 | *address = 0; |
| 186 | for (;;) { |
| 187 | ret = vm_region(task_self(), |
| 188 | ®ion.address, |
| 189 | ®ion.size, |
| 190 | ®ion.protection, |
| 191 | ®ion.max_protection, |
| 192 | ®ion.inheritance, |
| 193 | ®ion.shared, |
| 194 | ®ion.object_name, |
| 195 | ®ion.offset); |
| 196 | if (ret != KERN_SUCCESS || region.address >= VM_HIGHDATA) { |
| 197 | break; |
| 198 | } |
| 199 | if (*address != 0) { |
| 200 | if (region.address > *address + *size) { |
| 201 | if (!filldatagap(*address, size, |
| 202 | region.address)) { |
| 203 | return (0); |
| 204 | } |
| 205 | } |
| 206 | *size += region.size; |
| 207 | } else { |
| 208 | if (region.address == sect->addr) { |
| 209 | *address = region.address; |
| 210 | *size = region.size; |
| 211 | } |
| 212 | } |
| 213 | region.address += region.size; |
| 214 | } |
| 215 | return (1); |
| 216 | } |
| 217 | |
| 218 | static char * |
| 219 | my_malloc( |
| 220 | vm_size_t size |
| 221 | ) |
| 222 | { |
| 223 | vm_address_t address; |
| 224 | |
| 225 | if (vm_allocate(task_self(), &address, size, TRUE) != KERN_SUCCESS) { |
| 226 | return (NULL); |
| 227 | } |
| 228 | return ((char *)address); |
| 229 | } |
| 230 | |
| 231 | static void |
| 232 | my_free( |
| 233 | char *buf, |
| 234 | vm_size_t size |
| 235 | ) |
| 236 | { |
| 237 | vm_deallocate(task_self(), (vm_address_t)buf, size); |
| 238 | } |
| 239 | |
| 240 | static int |
| 241 | unexec_doit( |
| 242 | int infd, |
| 243 | int outfd |
| 244 | ) |
| 245 | { |
| 246 | int i; |
| 247 | struct load_command **the_commands = NULL; |
| 248 | unsigned the_commands_len; |
| 249 | struct mach_header the_header; |
| 250 | int fgrowth = 0; |
| 251 | int fdatastart; |
| 252 | int fdatasize; |
| 253 | int size; |
| 254 | struct stat st; |
| 255 | char *buf; |
| 256 | vm_address_t data_address; |
| 257 | vm_size_t data_size; |
| 258 | vm_size_t vmaddr_growth = 0; |
| 259 | vm_size_t dataseg_vmaddr, dataseg_vmend; |
| 260 | |
| 261 | struct segment_command *segment; |
| 262 | |
| 263 | #ifdef NS_TARGET |
| 264 | unsigned long extreloff = 0; |
| 265 | unsigned long nextrel = 0; |
| 266 | struct dysymtab_command *dysymtab; |
| 267 | struct relocation_info reloc_info; |
| 268 | #endif |
| 269 | |
| 270 | if (!read_macho(infd, &the_header, &the_commands, &the_commands_len)) { |
| 271 | return (0); |
| 272 | } |
| 273 | |
| 274 | |
| 275 | malloc_cookie = malloc_freezedry (); |
| 276 | if (!get_data_region(&data_address, &data_size)) { |
| 277 | return (0); |
| 278 | } |
| 279 | |
| 280 | |
| 281 | /* |
| 282 | * DO NOT USE MALLOC IN THIS SECTION |
| 283 | */ |
| 284 | { |
| 285 | /* |
| 286 | * Fix offsets |
| 287 | */ |
| 288 | for (i = 0; i < the_commands_len; i++) { |
| 289 | switch (the_commands[i]->cmd) { |
| 290 | case LC_SEGMENT: |
| 291 | segment = ((struct segment_command *) |
| 292 | the_commands[i]); |
| 293 | if (strcmp(segment->segname, SEG_DATA) == 0) { |
| 294 | fdatastart = segment->fileoff; |
| 295 | fdatasize = segment->filesize; |
| 296 | fgrowth = (data_size - |
| 297 | segment->filesize); |
| 298 | segment->vmsize = data_size; |
| 299 | segment->filesize = data_size; |
| 300 | dataseg_vmaddr = segment->vmaddr; |
| 301 | dataseg_vmend = segment->vmaddr + segment->vmsize; |
| 302 | vmaddr_growth = segment->vmaddr + segment->vmsize; |
| 303 | } else { |
| 304 | ((struct segment_command *)the_commands[i])->fileoff += fgrowth; |
| 305 | } |
| 306 | |
| 307 | if( strcmp( segment->segname, SEG_LINKEDIT ) == 0 ) { |
| 308 | segment->vmaddr = vmaddr_growth; |
| 309 | } |
| 310 | |
| 311 | break; |
| 312 | case LC_SYMTAB: |
| 313 | ((struct symtab_command *) |
| 314 | the_commands[i])->symoff += fgrowth; |
| 315 | ((struct symtab_command *) |
| 316 | the_commands[i])->stroff += fgrowth; |
| 317 | break; |
| 318 | case LC_SYMSEG: |
| 319 | ((struct symseg_command *) |
| 320 | the_commands[i])->offset += fgrowth; |
| 321 | break; |
| 322 | #ifdef NS_TARGET |
| 323 | case LC_DYSYMTAB: |
| 324 | dysymtab = ((struct dysymtab_command *)the_commands[i]); |
| 325 | extreloff = dysymtab->extreloff; |
| 326 | nextrel = dysymtab->nextrel; |
| 327 | dysymtab->indirectsymoff += fgrowth; |
| 328 | dysymtab->extreloff += fgrowth; |
| 329 | break; |
| 330 | #endif |
| 331 | default: |
| 332 | break; |
| 333 | } |
| 334 | } |
| 335 | |
| 336 | /* |
| 337 | * Write header |
| 338 | */ |
| 339 | if (write(outfd, &the_header, |
| 340 | sizeof(the_header)) != sizeof(the_header)) { |
| 341 | fatal_unexec("cannot write output file"); |
| 342 | return (0); |
| 343 | } |
| 344 | |
| 345 | /* |
| 346 | * Write commands |
| 347 | */ |
| 348 | for (i = 0; i < the_commands_len; i++) { |
| 349 | if (write(outfd, the_commands[i], |
| 350 | the_commands[i]->cmdsize) != |
| 351 | the_commands[i]->cmdsize) { |
| 352 | fatal_unexec("cannot write output file"); |
| 353 | return (0); |
| 354 | } |
| 355 | } |
| 356 | |
| 357 | /* |
| 358 | * Write original text |
| 359 | */ |
| 360 | if (lseek(infd, the_header.sizeofcmds + sizeof(the_header), |
| 361 | L_SET) < 0) { |
| 362 | fatal_unexec("cannot seek input file"); |
| 363 | return (0); |
| 364 | } |
| 365 | size = fdatastart - (sizeof(the_header) + |
| 366 | the_header.sizeofcmds); |
| 367 | buf = my_malloc(size); |
| 368 | if (read(infd, buf, size) != size) { |
| 369 | my_free(buf, size); |
| 370 | fatal_unexec("cannot read input file"); |
| 371 | } |
| 372 | if (write(outfd, buf, size) != size) { |
| 373 | my_free(buf, size); |
| 374 | fatal_unexec("cannot write output file"); |
| 375 | return (0); |
| 376 | } |
| 377 | my_free(buf, size); |
| 378 | |
| 379 | |
| 380 | /* |
| 381 | * Write new data |
| 382 | */ |
| 383 | if (write(outfd, (char *)data_address, |
| 384 | data_size) != data_size) { |
| 385 | fatal_unexec("cannot write output file"); |
| 386 | return (0); |
| 387 | } |
| 388 | |
| 389 | } |
| 390 | |
| 391 | /* |
| 392 | * OKAY TO USE MALLOC NOW |
| 393 | */ |
| 394 | |
| 395 | /* |
| 396 | * Write rest of file |
| 397 | */ |
| 398 | fstat(infd, &st); |
| 399 | if (lseek(infd, fdatasize, L_INCR) < 0) { |
| 400 | fatal_unexec("cannot seek input file"); |
| 401 | return (0); |
| 402 | } |
| 403 | size = st.st_size - lseek(infd, 0, L_INCR); |
| 404 | |
| 405 | buf = malloc(size); |
| 406 | if (read(infd, buf, size) != size) { |
| 407 | free(buf); |
| 408 | fatal_unexec("cannot read input file"); |
| 409 | return (0); |
| 410 | } |
| 411 | if (write(outfd, buf, size) != size) { |
| 412 | free(buf); |
| 413 | fatal_unexec("cannot write output file"); |
| 414 | return (0); |
| 415 | } |
| 416 | free(buf); |
| 417 | |
| 418 | #ifdef NS_TARGET |
| 419 | /* |
| 420 | * Fix up relocation entries in the data segment. |
| 421 | */ |
| 422 | |
| 423 | if (lseek(infd, extreloff, L_SET) < 0) { |
| 424 | fatal_unexec("cannot seek input file"); |
| 425 | return (0); |
| 426 | } |
| 427 | |
| 428 | for (i = 0; i < nextrel; i++) |
| 429 | { |
| 430 | long zeroval = 0; |
| 431 | |
| 432 | if (read(infd, &reloc_info, sizeof (reloc_info)) != sizeof (reloc_info)) { |
| 433 | fatal_unexec("cannot read input file"); |
| 434 | return (0); |
| 435 | } |
| 436 | if (reloc_info.r_address >= dataseg_vmaddr && reloc_info.r_address < dataseg_vmend) |
| 437 | { |
| 438 | if (lseek (outfd, fdatastart + reloc_info.r_address - dataseg_vmaddr, L_SET) < 0 ) { |
| 439 | fatal_unexec("cannot seek input file"); |
| 440 | return (0); |
| 441 | } |
| 442 | switch (reloc_info.r_length) { |
| 443 | case 0: |
| 444 | if (write(outfd, &zeroval, 1) != 1) { |
| 445 | fatal_unexec("cannot write output file"); |
| 446 | return (0); |
| 447 | } |
| 448 | break; |
| 449 | case 1: |
| 450 | if (write(outfd, &zeroval, 2) != 2) { |
| 451 | fatal_unexec("cannot write output file"); |
| 452 | return (0); |
| 453 | } |
| 454 | break; |
| 455 | case 2: |
| 456 | if (write(outfd, &zeroval, 4) != 4) { |
| 457 | fatal_unexec("cannot write output file"); |
| 458 | return (0); |
| 459 | } |
| 460 | break; |
| 461 | } |
| 462 | } |
| 463 | } |
| 464 | #endif |
| 465 | |
| 466 | return (1); |
| 467 | } |
| 468 | |
| 469 | void |
| 470 | unexec( |
| 471 | char *outfile, |
| 472 | char *infile |
| 473 | ) |
| 474 | { |
| 475 | int infd; |
| 476 | int outfd; |
| 477 | char tmpbuf[L_tmpnam]; |
| 478 | char *tmpfile; |
| 479 | |
| 480 | infd = open(infile, O_RDONLY, 0); |
| 481 | if (infd < 0) { |
| 482 | fatal_unexec("cannot open input file `%s'", infile); |
| 483 | exit(1); |
| 484 | } |
| 485 | |
| 486 | tmpnam(tmpbuf); |
| 487 | tmpfile = rindex(tmpbuf, '/'); |
| 488 | if (tmpfile == NULL) { |
| 489 | tmpfile = tmpbuf; |
| 490 | } else { |
| 491 | tmpfile++; |
| 492 | } |
| 493 | outfd = open(tmpfile, O_WRONLY|O_TRUNC|O_CREAT, 0755); |
| 494 | if (outfd < 0) { |
| 495 | close(infd); |
| 496 | fatal_unexec("cannot open tmp file `%s'", tmpfile); |
| 497 | exit(1); |
| 498 | } |
| 499 | if (!unexec_doit(infd, outfd)) { |
| 500 | close(infd); |
| 501 | close(outfd); |
| 502 | unlink(tmpfile); |
| 503 | exit(1); |
| 504 | } |
| 505 | close(infd); |
| 506 | close(outfd); |
| 507 | if (rename(tmpfile, outfile) < 0) { |
| 508 | unlink(tmpfile); |
| 509 | fatal_unexec("cannot rename `%s' to `%s'", tmpfile, outfile); |
| 510 | exit(1); |
| 511 | } |
| 512 | } |