| 1 | /* Dump an executable image. |
| 2 | Copyright (C) 1985-1988, 1999, 2001-2013 Free Software Foundation, |
| 3 | Inc. |
| 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 3 of the License, or |
| 10 | (at your option) 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. If not, see <http://www.gnu.org/licenses/>. */ |
| 19 | |
| 20 | /* |
| 21 | In other words, you are welcome to use, share and improve this program. |
| 22 | You are forbidden to forbid anyone else to use, share and improve |
| 23 | what you give them. Help stamp out software-hoarding! */ |
| 24 | |
| 25 | |
| 26 | /* Originally based on the COFF unexec.c by Spencer W. Thomas. |
| 27 | * |
| 28 | * Subsequently hacked on by |
| 29 | * Bill Mann <Bill_Man@praxisint.com> |
| 30 | * Andrew Vignaux <Andrew.Vignaux@comp.vuw.ac.nz> |
| 31 | * Mike Sperber <sperber@informatik.uni-tuebingen.de> |
| 32 | * |
| 33 | * Synopsis: |
| 34 | * unexec (const char *new_name, const *old_name); |
| 35 | * |
| 36 | * Takes a snapshot of the program and makes an a.out format file in the |
| 37 | * file named by the string argument new_name. |
| 38 | * If a_name is non-NULL, the symbol table will be taken from the given file. |
| 39 | * On some machines, an existing a_name file is required. |
| 40 | * |
| 41 | */ |
| 42 | |
| 43 | #include <config.h> |
| 44 | #include "unexec.h" |
| 45 | |
| 46 | #define PERROR(file) report_error (file, new) |
| 47 | #include <a.out.h> |
| 48 | /* Define getpagesize () if the system does not. |
| 49 | Note that this may depend on symbols defined in a.out.h |
| 50 | */ |
| 51 | #include "getpagesize.h" |
| 52 | |
| 53 | #include <sys/types.h> |
| 54 | #include <stdio.h> |
| 55 | #include <sys/stat.h> |
| 56 | #include <errno.h> |
| 57 | #include <unistd.h> |
| 58 | #include <fcntl.h> |
| 59 | |
| 60 | #include "mem-limits.h" |
| 61 | |
| 62 | char *start_of_text (void); /* Start of text */ |
| 63 | |
| 64 | extern int _data; |
| 65 | extern int _text; |
| 66 | |
| 67 | #include <filehdr.h> |
| 68 | #include <aouthdr.h> |
| 69 | #include <scnhdr.h> |
| 70 | #include <syms.h> |
| 71 | |
| 72 | static struct filehdr f_hdr; /* File header */ |
| 73 | static struct aouthdr f_ohdr; /* Optional file header (a.out) */ |
| 74 | static long bias; /* Bias to add for growth */ |
| 75 | static long lnnoptr; /* Pointer to line-number info within file */ |
| 76 | |
| 77 | static long text_scnptr; |
| 78 | static long data_scnptr; |
| 79 | #define ALIGN(val, pwr) (((val) + ((1L<<(pwr))-1)) & ~((1L<<(pwr))-1)) |
| 80 | static long load_scnptr; |
| 81 | static long orig_load_scnptr; |
| 82 | static long orig_data_scnptr; |
| 83 | static int unrelocate_symbols (int, int, const char *, const char *); |
| 84 | |
| 85 | #ifndef MAX_SECTIONS |
| 86 | #define MAX_SECTIONS 10 |
| 87 | #endif |
| 88 | |
| 89 | static int adjust_lnnoptrs (int, int, const char *); |
| 90 | |
| 91 | static int pagemask; |
| 92 | |
| 93 | #include "lisp.h" |
| 94 | |
| 95 | static void |
| 96 | report_error (const char *file, int fd) |
| 97 | { |
| 98 | if (fd) |
| 99 | close (fd); |
| 100 | report_file_error ("Cannot unexec", Fcons (build_string (file), Qnil)); |
| 101 | } |
| 102 | |
| 103 | #define ERROR0(msg) report_error_1 (new, msg, 0, 0); return -1 |
| 104 | #define ERROR1(msg,x) report_error_1 (new, msg, x, 0); return -1 |
| 105 | #define ERROR2(msg,x,y) report_error_1 (new, msg, x, y); return -1 |
| 106 | |
| 107 | static void |
| 108 | report_error_1 (int fd, const char *msg, int a1, int a2) |
| 109 | { |
| 110 | close (fd); |
| 111 | error (msg, a1, a2); |
| 112 | } |
| 113 | |
| 114 | static int make_hdr (int, int, const char *, const char *); |
| 115 | static void mark_x (const char *); |
| 116 | static int copy_text_and_data (int); |
| 117 | static int copy_sym (int, int, const char *, const char *); |
| 118 | static void write_segment (int, char *, char *); |
| 119 | \f |
| 120 | /* **************************************************************** |
| 121 | * unexec |
| 122 | * |
| 123 | * driving logic. |
| 124 | */ |
| 125 | void |
| 126 | unexec (const char *new_name, const char *a_name) |
| 127 | { |
| 128 | int new = -1, a_out = -1; |
| 129 | |
| 130 | if (a_name && (a_out = open (a_name, O_RDONLY)) < 0) |
| 131 | { |
| 132 | PERROR (a_name); |
| 133 | } |
| 134 | if ((new = creat (new_name, 0666)) < 0) |
| 135 | { |
| 136 | PERROR (new_name); |
| 137 | } |
| 138 | if (make_hdr (new, a_out, |
| 139 | a_name, new_name) < 0 |
| 140 | || copy_text_and_data (new) < 0 |
| 141 | || copy_sym (new, a_out, a_name, new_name) < 0 |
| 142 | || adjust_lnnoptrs (new, a_out, new_name) < 0 |
| 143 | || unrelocate_symbols (new, a_out, a_name, new_name) < 0) |
| 144 | { |
| 145 | close (new); |
| 146 | return; |
| 147 | } |
| 148 | |
| 149 | close (new); |
| 150 | if (a_out >= 0) |
| 151 | close (a_out); |
| 152 | mark_x (new_name); |
| 153 | } |
| 154 | |
| 155 | /* **************************************************************** |
| 156 | * make_hdr |
| 157 | * |
| 158 | * Make the header in the new a.out from the header in core. |
| 159 | * Modify the text and data sizes. |
| 160 | */ |
| 161 | static int |
| 162 | make_hdr (int new, int a_out, |
| 163 | const char *a_name, const char *new_name) |
| 164 | { |
| 165 | int scns; |
| 166 | unsigned int bss_start; |
| 167 | unsigned int data_start; |
| 168 | |
| 169 | struct scnhdr section[MAX_SECTIONS]; |
| 170 | struct scnhdr * f_thdr; /* Text section header */ |
| 171 | struct scnhdr * f_dhdr; /* Data section header */ |
| 172 | struct scnhdr * f_bhdr; /* Bss section header */ |
| 173 | struct scnhdr * f_lhdr; /* Loader section header */ |
| 174 | struct scnhdr * f_tchdr; /* Typechk section header */ |
| 175 | struct scnhdr * f_dbhdr; /* Debug section header */ |
| 176 | struct scnhdr * f_xhdr; /* Except section header */ |
| 177 | |
| 178 | load_scnptr = orig_load_scnptr = lnnoptr = 0; |
| 179 | pagemask = getpagesize () - 1; |
| 180 | |
| 181 | /* Adjust text/data boundary. */ |
| 182 | data_start = (long) start_of_data (); |
| 183 | data_start = ADDR_CORRECT (data_start); |
| 184 | |
| 185 | data_start = data_start & ~pagemask; /* (Down) to page boundary. */ |
| 186 | |
| 187 | bss_start = ADDR_CORRECT (sbrk (0)) + pagemask; |
| 188 | bss_start &= ~ pagemask; |
| 189 | |
| 190 | if (data_start > bss_start) /* Can't have negative data size. */ |
| 191 | { |
| 192 | ERROR2 ("unexec: data_start (%u) can't be greater than bss_start (%u)", |
| 193 | data_start, bss_start); |
| 194 | } |
| 195 | |
| 196 | /* Salvage as much info from the existing file as possible */ |
| 197 | f_thdr = NULL; f_dhdr = NULL; f_bhdr = NULL; |
| 198 | f_lhdr = NULL; f_tchdr = NULL; f_dbhdr = NULL; f_xhdr = NULL; |
| 199 | if (a_out >= 0) |
| 200 | { |
| 201 | if (read (a_out, &f_hdr, sizeof (f_hdr)) != sizeof (f_hdr)) |
| 202 | { |
| 203 | PERROR (a_name); |
| 204 | } |
| 205 | if (f_hdr.f_opthdr > 0) |
| 206 | { |
| 207 | if (read (a_out, &f_ohdr, sizeof (f_ohdr)) != sizeof (f_ohdr)) |
| 208 | { |
| 209 | PERROR (a_name); |
| 210 | } |
| 211 | } |
| 212 | if (f_hdr.f_nscns > MAX_SECTIONS) |
| 213 | { |
| 214 | ERROR0 ("unexec: too many section headers -- increase MAX_SECTIONS"); |
| 215 | } |
| 216 | /* Loop through section headers */ |
| 217 | for (scns = 0; scns < f_hdr.f_nscns; scns++) { |
| 218 | struct scnhdr *s = §ion[scns]; |
| 219 | if (read (a_out, s, sizeof (*s)) != sizeof (*s)) |
| 220 | { |
| 221 | PERROR (a_name); |
| 222 | } |
| 223 | |
| 224 | #define CHECK_SCNHDR(ptr, name, flags) \ |
| 225 | if (strcmp (s->s_name, name) == 0) { \ |
| 226 | if (s->s_flags != flags) { \ |
| 227 | fprintf (stderr, "unexec: %lx flags where %x expected in %s section.\n", \ |
| 228 | (unsigned long)s->s_flags, flags, name); \ |
| 229 | } \ |
| 230 | if (ptr) { \ |
| 231 | fprintf (stderr, "unexec: duplicate section header for section %s.\n", \ |
| 232 | name); \ |
| 233 | } \ |
| 234 | ptr = s; \ |
| 235 | } |
| 236 | CHECK_SCNHDR (f_thdr, _TEXT, STYP_TEXT); |
| 237 | CHECK_SCNHDR (f_dhdr, _DATA, STYP_DATA); |
| 238 | CHECK_SCNHDR (f_bhdr, _BSS, STYP_BSS); |
| 239 | CHECK_SCNHDR (f_lhdr, _LOADER, STYP_LOADER); |
| 240 | CHECK_SCNHDR (f_dbhdr, _DEBUG, STYP_DEBUG); |
| 241 | CHECK_SCNHDR (f_tchdr, _TYPCHK, STYP_TYPCHK); |
| 242 | CHECK_SCNHDR (f_xhdr, _EXCEPT, STYP_EXCEPT); |
| 243 | } |
| 244 | |
| 245 | if (f_thdr == 0) |
| 246 | { |
| 247 | ERROR1 ("unexec: couldn't find \"%s\" section", (int) _TEXT); |
| 248 | } |
| 249 | if (f_dhdr == 0) |
| 250 | { |
| 251 | ERROR1 ("unexec: couldn't find \"%s\" section", (int) _DATA); |
| 252 | } |
| 253 | if (f_bhdr == 0) |
| 254 | { |
| 255 | ERROR1 ("unexec: couldn't find \"%s\" section", (int) _BSS); |
| 256 | } |
| 257 | } |
| 258 | else |
| 259 | { |
| 260 | ERROR0 ("can't build a COFF file from scratch yet"); |
| 261 | } |
| 262 | orig_data_scnptr = f_dhdr->s_scnptr; |
| 263 | orig_load_scnptr = f_lhdr ? f_lhdr->s_scnptr : 0; |
| 264 | |
| 265 | /* Now we alter the contents of all the f_*hdr variables |
| 266 | to correspond to what we want to dump. */ |
| 267 | |
| 268 | /* Indicate that the reloc information is no longer valid for ld (bind); |
| 269 | we only update it enough to fake out the exec-time loader. */ |
| 270 | f_hdr.f_flags |= (F_RELFLG | F_EXEC); |
| 271 | |
| 272 | f_ohdr.dsize = bss_start - f_ohdr.data_start; |
| 273 | f_ohdr.bsize = 0; |
| 274 | |
| 275 | f_dhdr->s_size = f_ohdr.dsize; |
| 276 | f_bhdr->s_size = f_ohdr.bsize; |
| 277 | f_bhdr->s_paddr = f_ohdr.data_start + f_ohdr.dsize; |
| 278 | f_bhdr->s_vaddr = f_ohdr.data_start + f_ohdr.dsize; |
| 279 | |
| 280 | /* fix scnptr's */ |
| 281 | { |
| 282 | ulong ptr = section[0].s_scnptr; |
| 283 | |
| 284 | bias = -1; |
| 285 | for (scns = 0; scns < f_hdr.f_nscns; scns++) |
| 286 | { |
| 287 | struct scnhdr *s = §ion[scns]; |
| 288 | |
| 289 | if (s->s_flags & STYP_PAD) /* .pad sections omitted in AIX 4.1 */ |
| 290 | { |
| 291 | /* |
| 292 | * the text_start should probably be o_algntext but that doesn't |
| 293 | * seem to change |
| 294 | */ |
| 295 | if (f_ohdr.text_start != 0) /* && scns != 0 */ |
| 296 | { |
| 297 | s->s_size = 512 - (ptr % 512); |
| 298 | if (s->s_size == 512) |
| 299 | s->s_size = 0; |
| 300 | } |
| 301 | s->s_scnptr = ptr; |
| 302 | } |
| 303 | else if (s->s_flags & STYP_DATA) |
| 304 | s->s_scnptr = ptr; |
| 305 | else if (!(s->s_flags & (STYP_TEXT | STYP_BSS))) |
| 306 | { |
| 307 | if (bias == -1) /* if first section after bss */ |
| 308 | bias = ptr - s->s_scnptr; |
| 309 | |
| 310 | s->s_scnptr += bias; |
| 311 | ptr = s->s_scnptr; |
| 312 | } |
| 313 | |
| 314 | ptr = ptr + s->s_size; |
| 315 | } |
| 316 | } |
| 317 | |
| 318 | /* fix other pointers */ |
| 319 | for (scns = 0; scns < f_hdr.f_nscns; scns++) |
| 320 | { |
| 321 | struct scnhdr *s = §ion[scns]; |
| 322 | |
| 323 | if (s->s_relptr != 0) |
| 324 | { |
| 325 | s->s_relptr += bias; |
| 326 | } |
| 327 | if (s->s_lnnoptr != 0) |
| 328 | { |
| 329 | if (lnnoptr == 0) lnnoptr = s->s_lnnoptr; |
| 330 | s->s_lnnoptr += bias; |
| 331 | } |
| 332 | } |
| 333 | |
| 334 | if (f_hdr.f_symptr > 0L) |
| 335 | { |
| 336 | f_hdr.f_symptr += bias; |
| 337 | } |
| 338 | |
| 339 | text_scnptr = f_thdr->s_scnptr; |
| 340 | data_scnptr = f_dhdr->s_scnptr; |
| 341 | load_scnptr = f_lhdr ? f_lhdr->s_scnptr : 0; |
| 342 | |
| 343 | if (write (new, &f_hdr, sizeof (f_hdr)) != sizeof (f_hdr)) |
| 344 | { |
| 345 | PERROR (new_name); |
| 346 | } |
| 347 | |
| 348 | if (f_hdr.f_opthdr > 0) |
| 349 | { |
| 350 | if (write (new, &f_ohdr, sizeof (f_ohdr)) != sizeof (f_ohdr)) |
| 351 | { |
| 352 | PERROR (new_name); |
| 353 | } |
| 354 | } |
| 355 | |
| 356 | for (scns = 0; scns < f_hdr.f_nscns; scns++) { |
| 357 | struct scnhdr *s = §ion[scns]; |
| 358 | if (write (new, s, sizeof (*s)) != sizeof (*s)) |
| 359 | { |
| 360 | PERROR (new_name); |
| 361 | } |
| 362 | } |
| 363 | |
| 364 | return (0); |
| 365 | } |
| 366 | \f |
| 367 | /* **************************************************************** |
| 368 | |
| 369 | * |
| 370 | * Copy the text and data segments from memory to the new a.out |
| 371 | */ |
| 372 | static int |
| 373 | copy_text_and_data (int new) |
| 374 | { |
| 375 | char *end; |
| 376 | char *ptr; |
| 377 | |
| 378 | lseek (new, (long) text_scnptr, SEEK_SET); |
| 379 | ptr = start_of_text () + text_scnptr; |
| 380 | end = ptr + f_ohdr.tsize; |
| 381 | write_segment (new, ptr, end); |
| 382 | |
| 383 | lseek (new, (long) data_scnptr, SEEK_SET); |
| 384 | ptr = (char *) f_ohdr.data_start; |
| 385 | end = ptr + f_ohdr.dsize; |
| 386 | write_segment (new, ptr, end); |
| 387 | |
| 388 | return 0; |
| 389 | } |
| 390 | |
| 391 | #define UnexBlockSz (1<<12) /* read/write block size */ |
| 392 | static void |
| 393 | write_segment (int new, char *ptr, char *end) |
| 394 | { |
| 395 | int i, nwrite, ret; |
| 396 | char buf[80]; |
| 397 | char zeros[UnexBlockSz]; |
| 398 | |
| 399 | for (i = 0; ptr < end;) |
| 400 | { |
| 401 | /* distance to next block. */ |
| 402 | nwrite = (((int) ptr + UnexBlockSz) & -UnexBlockSz) - (int) ptr; |
| 403 | /* But not beyond specified end. */ |
| 404 | if (nwrite > end - ptr) nwrite = end - ptr; |
| 405 | ret = write (new, ptr, nwrite); |
| 406 | /* If write gets a page fault, it means we reached |
| 407 | a gap between the old text segment and the old data segment. |
| 408 | This gap has probably been remapped into part of the text segment. |
| 409 | So write zeros for it. */ |
| 410 | if (ret == -1 && errno == EFAULT) |
| 411 | { |
| 412 | memset (zeros, 0, nwrite); |
| 413 | write (new, zeros, nwrite); |
| 414 | } |
| 415 | else if (nwrite != ret) |
| 416 | { |
| 417 | sprintf (buf, |
| 418 | "unexec write failure: addr 0x%lx, fileno %d, size 0x%x, wrote 0x%x, errno %d", |
| 419 | (unsigned long)ptr, new, nwrite, ret, errno); |
| 420 | PERROR (buf); |
| 421 | } |
| 422 | i += nwrite; |
| 423 | ptr += nwrite; |
| 424 | } |
| 425 | } |
| 426 | \f |
| 427 | /* **************************************************************** |
| 428 | * copy_sym |
| 429 | * |
| 430 | * Copy the relocation information and symbol table from the a.out to the new |
| 431 | */ |
| 432 | static int |
| 433 | copy_sym (int new, int a_out, const char *a_name, const char *new_name) |
| 434 | { |
| 435 | char page[UnexBlockSz]; |
| 436 | int n; |
| 437 | |
| 438 | if (a_out < 0) |
| 439 | return 0; |
| 440 | |
| 441 | if (orig_load_scnptr == 0L) |
| 442 | return 0; |
| 443 | |
| 444 | if (lnnoptr && lnnoptr < orig_load_scnptr) /* if there is line number info */ |
| 445 | lseek (a_out, lnnoptr, SEEK_SET); /* start copying from there */ |
| 446 | else |
| 447 | lseek (a_out, orig_load_scnptr, SEEK_SET); /* Position a.out to symtab. */ |
| 448 | |
| 449 | while ((n = read (a_out, page, sizeof page)) > 0) |
| 450 | { |
| 451 | if (write (new, page, n) != n) |
| 452 | { |
| 453 | PERROR (new_name); |
| 454 | } |
| 455 | } |
| 456 | if (n < 0) |
| 457 | { |
| 458 | PERROR (a_name); |
| 459 | } |
| 460 | return 0; |
| 461 | } |
| 462 | \f |
| 463 | /* **************************************************************** |
| 464 | * mark_x |
| 465 | * |
| 466 | * After successfully building the new a.out, mark it executable |
| 467 | */ |
| 468 | static void |
| 469 | mark_x (const char *name) |
| 470 | { |
| 471 | struct stat sbuf; |
| 472 | int um; |
| 473 | int new = 0; /* for PERROR */ |
| 474 | |
| 475 | um = umask (777); |
| 476 | umask (um); |
| 477 | if (stat (name, &sbuf) == -1) |
| 478 | { |
| 479 | PERROR (name); |
| 480 | } |
| 481 | sbuf.st_mode |= 0111 & ~um; |
| 482 | if (chmod (name, sbuf.st_mode) == -1) |
| 483 | PERROR (name); |
| 484 | } |
| 485 | \f |
| 486 | static int |
| 487 | adjust_lnnoptrs (int writedesc, int readdesc, const char *new_name) |
| 488 | { |
| 489 | int nsyms; |
| 490 | int naux; |
| 491 | int new; |
| 492 | struct syment symentry; |
| 493 | union auxent auxentry; |
| 494 | |
| 495 | if (!lnnoptr || !f_hdr.f_symptr) |
| 496 | return 0; |
| 497 | |
| 498 | if ((new = open (new_name, O_RDWR)) < 0) |
| 499 | { |
| 500 | PERROR (new_name); |
| 501 | return -1; |
| 502 | } |
| 503 | |
| 504 | lseek (new, f_hdr.f_symptr, SEEK_SET); |
| 505 | for (nsyms = 0; nsyms < f_hdr.f_nsyms; nsyms++) |
| 506 | { |
| 507 | read (new, &symentry, SYMESZ); |
| 508 | if (symentry.n_sclass == C_BINCL || symentry.n_sclass == C_EINCL) |
| 509 | { |
| 510 | symentry.n_value += bias; |
| 511 | lseek (new, -SYMESZ, SEEK_CUR); |
| 512 | write (new, &symentry, SYMESZ); |
| 513 | } |
| 514 | |
| 515 | for (naux = symentry.n_numaux; naux-- != 0; ) |
| 516 | { |
| 517 | read (new, &auxentry, AUXESZ); |
| 518 | nsyms++; |
| 519 | if (naux != 0 /* skip csect auxentry (last entry) */ |
| 520 | && (symentry.n_sclass == C_EXT || symentry.n_sclass == C_HIDEXT)) |
| 521 | { |
| 522 | auxentry.x_sym.x_fcnary.x_fcn.x_lnnoptr += bias; |
| 523 | lseek (new, -AUXESZ, SEEK_CUR); |
| 524 | write (new, &auxentry, AUXESZ); |
| 525 | } |
| 526 | } |
| 527 | } |
| 528 | close (new); |
| 529 | |
| 530 | return 0; |
| 531 | } |
| 532 | |
| 533 | static int |
| 534 | unrelocate_symbols (int new, int a_out, |
| 535 | const char *a_name, const char *new_name) |
| 536 | { |
| 537 | int i; |
| 538 | LDHDR ldhdr; |
| 539 | LDREL ldrel; |
| 540 | ulong t_reloc = (ulong) &_text - f_ohdr.text_start; |
| 541 | #ifndef ALIGN_DATA_RELOC |
| 542 | ulong d_reloc = (ulong) &_data - f_ohdr.data_start; |
| 543 | #else |
| 544 | /* This worked (and was needed) before AIX 4.2. |
| 545 | I have no idea why. -- Mike */ |
| 546 | ulong d_reloc = (ulong) &_data - ALIGN (f_ohdr.data_start, 2); |
| 547 | #endif |
| 548 | int * p; |
| 549 | |
| 550 | if (load_scnptr == 0) |
| 551 | return 0; |
| 552 | |
| 553 | lseek (a_out, orig_load_scnptr, SEEK_SET); |
| 554 | if (read (a_out, &ldhdr, sizeof (ldhdr)) != sizeof (ldhdr)) |
| 555 | { |
| 556 | PERROR (new_name); |
| 557 | } |
| 558 | |
| 559 | #define SYMNDX_TEXT 0 |
| 560 | #define SYMNDX_DATA 1 |
| 561 | #define SYMNDX_BSS 2 |
| 562 | |
| 563 | for (i = 0; i < ldhdr.l_nreloc; i++) |
| 564 | { |
| 565 | lseek (a_out, |
| 566 | orig_load_scnptr + LDHDRSZ + LDSYMSZ*ldhdr.l_nsyms + LDRELSZ*i, |
| 567 | SEEK_SET); |
| 568 | |
| 569 | if (read (a_out, &ldrel, LDRELSZ) != LDRELSZ) |
| 570 | { |
| 571 | PERROR (a_name); |
| 572 | } |
| 573 | |
| 574 | /* move the BSS loader symbols to the DATA segment */ |
| 575 | if (ldrel.l_symndx == SYMNDX_BSS) |
| 576 | { |
| 577 | ldrel.l_symndx = SYMNDX_DATA; |
| 578 | |
| 579 | lseek (new, |
| 580 | load_scnptr + LDHDRSZ + LDSYMSZ*ldhdr.l_nsyms + LDRELSZ*i, |
| 581 | SEEK_SET); |
| 582 | |
| 583 | if (write (new, &ldrel, LDRELSZ) != LDRELSZ) |
| 584 | { |
| 585 | PERROR (new_name); |
| 586 | } |
| 587 | } |
| 588 | |
| 589 | if (ldrel.l_rsecnm == f_ohdr.o_sndata) |
| 590 | { |
| 591 | int orig_int; |
| 592 | |
| 593 | lseek (a_out, |
| 594 | orig_data_scnptr + (ldrel.l_vaddr - f_ohdr.data_start), |
| 595 | SEEK_SET); |
| 596 | |
| 597 | if (read (a_out, (void *) &orig_int, sizeof (orig_int)) |
| 598 | != sizeof (orig_int)) |
| 599 | { |
| 600 | PERROR (a_name); |
| 601 | } |
| 602 | |
| 603 | p = (int *) (ldrel.l_vaddr + d_reloc); |
| 604 | |
| 605 | switch (ldrel.l_symndx) { |
| 606 | case SYMNDX_TEXT: |
| 607 | orig_int = * p - t_reloc; |
| 608 | break; |
| 609 | |
| 610 | case SYMNDX_DATA: |
| 611 | case SYMNDX_BSS: |
| 612 | orig_int = * p - d_reloc; |
| 613 | break; |
| 614 | } |
| 615 | |
| 616 | if (orig_int != * p) |
| 617 | { |
| 618 | lseek (new, |
| 619 | data_scnptr + (ldrel.l_vaddr - f_ohdr.data_start), |
| 620 | SEEK_SET); |
| 621 | if (write (new, (void *) &orig_int, sizeof (orig_int)) |
| 622 | != sizeof (orig_int)) |
| 623 | { |
| 624 | PERROR (new_name); |
| 625 | } |
| 626 | } |
| 627 | } |
| 628 | } |
| 629 | return 0; |
| 630 | } |
| 631 | |
| 632 | /* |
| 633 | * Return the address of the start of the text segment prior to |
| 634 | * doing an unexec. After unexec the return value is undefined. |
| 635 | * See crt0.c for further explanation and _start. |
| 636 | * |
| 637 | */ |
| 638 | |
| 639 | char * |
| 640 | start_of_text (void) |
| 641 | { |
| 642 | return ((char *) 0x10000000); |
| 643 | } |