0
+ − 1 /* Code to do an unexec for Sun O/S 4.1 for a temacs linked -Bdynamic.
+ − 2 Copyright (C) 1992, 1993 Free Software Foundation, Inc.
+ − 3
+ − 4 This file is part of XEmacs.
+ − 5
+ − 6 XEmacs is free software; you can redistribute it and/or modify it
+ − 7 under the terms of the GNU General Public License as published by the
+ − 8 Free Software Foundation; either version 2, or (at your option) any
+ − 9 later version.
+ − 10
+ − 11 XEmacs is distributed in the hope that it will be useful, but WITHOUT
+ − 12 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ − 13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ − 14 for more details.
+ − 15
+ − 16 You should have received a copy of the GNU General Public License
+ − 17 along with XEmacs; see the file COPYING. If not, write to
+ − 18 the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ − 19 Boston, MA 02111-1307, USA. */
+ − 20
+ − 21 /* Synched up with: Not synched with FSF. */
+ − 22
+ − 23 /*
+ − 24 Created 29-Oct-92 by Harlan Sexton
+ − 25 Tweaked 06-Aug-93 by Dean Michaels to work with sun3.
+ − 26 */
+ − 27
+ − 28 /********************** Included .h Files **************************/
+ − 29
+ − 30 #include <config.h>
+ − 31
+ − 32 /* I don't understand this, but it's necessary to get some slots in struct exec
+ − 33 from /usr/include/sys/exec.h when running LCC in strict ANSI mode. We don't
+ − 34 need this in K&R mode...
+ − 35 */
+ − 36 #if defined(__lucid) && defined(__sparc) && !defined(sun)
+ − 37 # define sun 1
+ − 38 #endif
+ − 39
+ − 40 #include <stdarg.h>
+ − 41 #include <sys/param.h>
+ − 42 #include <sys/mman.h>
+ − 43 #include <sys/file.h>
+ − 44 #include <sys/stat.h>
+ − 45 #include <sys/types.h>
+ − 46 #include <string.h>
+ − 47 #include <stdio.h>
+ − 48 #include <a.out.h>
+ − 49 #include <unistd.h>
+ − 50 #include <ctype.h>
+ − 51 #include <stab.h>
+ − 52 #include <sys/dir.h>
+ − 53 #include <link.h>
+ − 54
+ − 55 /********************** Macros *************************************/
+ − 56
+ − 57 #define SYS_ERR \
+ − 58 ((errno > 0)?((errno < sys_nerr)?(sys_errlist[errno]):\
+ − 59 "unknown system error"): "unknown error")
+ − 60
+ − 61 #define MASK_UP(x,p_of_two) \
+ − 62 ((((unsigned long) (x)) + ((p_of_two) - 1)) & (~((p_of_two) - 1)))
+ − 63
+ − 64 #define MASK_DOWN(x,p_of_two) (((unsigned long) (x)) & (~((p_of_two) - 1)))
+ − 65
+ − 66 #ifndef mc68020
+ − 67 #define relocation_info reloc_info_sparc
+ − 68 #endif
+ − 69
+ − 70 /********************** Typedefs and Structs ***********************/
+ − 71
+ − 72 struct translation_struct
+ − 73 {
+ − 74 long txtaddr;
+ − 75 long txtoff;
+ − 76 long dataddr;
+ − 77 long datoff;
+ − 78 long bssaddr;
+ − 79 };
+ − 80
+ − 81 /********************** Function Prototypes/Declarations ***********/
+ − 82
398
+ − 83 static void unexec_error (const char *m, int use_errno, ...);
0
+ − 84 static int unexec_open (char *filename, int flag, int mode);
+ − 85 static caddr_t unexec_mmap (int fd, size_t len, int prot, int flags);
+ − 86 static long unexec_seek (int fd, long position);
+ − 87 static void unexec_read (int fd, long position, char *buf, int bytes);
+ − 88 static void unexec_write (int fd, long position, char *buf, int bytes);
+ − 89 static void unexec_pad (int fd, int bytes);
+ − 90 static void unexec_fstat (int fd, struct stat *statptr);
+ − 91 static void unexec_fchmod (int fd, int mode);
+ − 92 static long unexec_addr_to_offset (long addr, struct translation_struct *ts);
+ − 93 static void copy_relocation_site (struct relocation_info *ri,
+ − 94 caddr_t from_base_addr,
+ − 95 caddr_t to_base_addr,
+ − 96 struct translation_struct *ts);
+ − 97 static void reset_symtab (struct nlist *start, struct nlist *end,
+ − 98 char *strtab, long edata_value, long end_value,
+ − 99 int ld_so_table, int shlib_image);
+ − 100 int run_time_remap (char *dummy);
+ − 101
+ − 102 /********************** Variables **********************************/
+ − 103
+ − 104 /* for reporting error messages from system calls */
+ − 105 extern int sys_nerr;
+ − 106 extern char *sys_errlist[];
+ − 107 extern int errno;
+ − 108 extern int _DYNAMIC;
+ − 109 extern char **environ;
+ − 110
+ − 111 static unsigned long mprotect_bottom_addr;
+ − 112 static unsigned long mprotect_top_addr;
+ − 113
+ − 114 static unsigned long sbrk_of_0_at_unexec;
+ − 115
+ − 116 /*******************************************************************/
+ − 117
+ − 118 static void
398
+ − 119 unexec_error (const char *fmt, int use_errno, ...)
0
+ − 120 {
398
+ − 121 const char *err_msg = SYS_ERR;
0
+ − 122 va_list args;
+ − 123
+ − 124 fprintf (stderr, "unexec - ");
+ − 125 va_start (args, use_errno);
+ − 126 vfprintf (stderr, fmt, args);
+ − 127 va_end (args);
+ − 128
+ − 129 if (use_errno)
+ − 130 fprintf (stderr, ": %s", err_msg);
+ − 131 fprintf (stderr, "\n");
+ − 132 exit (1);
+ − 133 return;
+ − 134 }
+ − 135
+ − 136 static int
+ − 137 unexec_open (char *filename, int flag, int mode)
+ − 138 {
+ − 139 int fd;
+ − 140
+ − 141 errno = 0;
+ − 142
+ − 143 fd = open (filename, flag, mode);
+ − 144
+ − 145 if (fd < 0)
+ − 146 unexec_error ("Failure opening file %s", 1, (void *) filename, 0, 0);
+ − 147 return fd;
+ − 148 }
+ − 149
+ − 150 static caddr_t
+ − 151 unexec_mmap (int fd, size_t len, int prot, int flags)
+ − 152 {
+ − 153 caddr_t return_val;
+ − 154
+ − 155 unexec_seek (fd, 0);
+ − 156 errno = 0;
+ − 157 return_val = mmap (0, len, prot, flags, fd, 0);
+ − 158
+ − 159 if (return_val == (caddr_t) -1)
+ − 160 unexec_error ("Failure mmap'ing file", 1, 0, 0, 0);
+ − 161 return return_val;
+ − 162 }
+ − 163
+ − 164
+ − 165 static long
+ − 166 unexec_seek (int fd, long position)
+ − 167 {
+ − 168 long seek_value;
+ − 169
+ − 170 if (fd <= 0)
+ − 171 unexec_error ("No file open in which to seek", 0, 0, 0, 0);
+ − 172
+ − 173 errno = 0;
+ − 174
+ − 175 if (position < 0)
+ − 176 seek_value = (long) lseek (fd, 0, L_INCR);
+ − 177 else
+ − 178 seek_value = (long) lseek (fd, position, L_SET);
+ − 179
+ − 180 if (seek_value < 0)
+ − 181 unexec_error ("Failed to do a seek to 0x%x in %s", 1,
+ − 182 (char *) position, "unexec() output file", 0);
+ − 183
+ − 184 return seek_value;
+ − 185 }
+ − 186
+ − 187 static void
+ − 188 unexec_read (int fd, long position, char *buf, int bytes)
+ − 189 {
+ − 190 int n_read;
+ − 191 int remains = bytes;
+ − 192 position = unexec_seek (fd, position);
+ − 193
+ − 194 if (bytes < 0)
+ − 195 unexec_error ("Attempted read of %d bytes", 0, (char *) bytes, 0, 0);
+ − 196
+ − 197 errno = 0;
+ − 198
+ − 199 while (remains > 0)
+ − 200 {
+ − 201 n_read = read (fd, buf, remains);
+ − 202 if (n_read <= 0)
+ − 203 unexec_error ("Read failed for 0x%x bytes at offset 0x%x in %s",
+ − 204 1, (char *) bytes, (char *) position,
+ − 205 "unexec() output file");
+ − 206 buf += n_read;
+ − 207 remains -= n_read;
+ − 208 }
+ − 209
+ − 210 return;
+ − 211 }
+ − 212
+ − 213 static void
+ − 214 unexec_write (int fd, long position, char *buf, int bytes)
+ − 215 {
+ − 216 int n_written;
+ − 217 int remains = bytes;
+ − 218 position = unexec_seek (fd, position);
+ − 219
+ − 220 if (bytes < 0)
+ − 221 unexec_error ("Attempted write of %d bytes in %s",
+ − 222 0, (char *) bytes, "unexec() output file", 0);
+ − 223
+ − 224 errno = 0;
+ − 225
+ − 226 while (remains > 0)
+ − 227 {
+ − 228 n_written = write (fd, buf, remains);
+ − 229 if (n_written <= 0)
+ − 230 unexec_error ("Write failed for 0x%x bytes at offset 0x%x in %s",
+ − 231 1, (char *) bytes, (char *) position,
+ − 232 "unexec() output file");
+ − 233 buf += n_written;
+ − 234 remains -= n_written;
+ − 235 }
+ − 236
+ − 237 return;
+ − 238 }
+ − 239
+ − 240 static void
+ − 241 unexec_pad (int fd, int bytes)
+ − 242 {
+ − 243 if (bytes > 0)
+ − 244 {
+ − 245 char buf[1024];
+ − 246 int remaining = bytes;
+ − 247
+ − 248 memset (buf, 0, sizeof (buf));
+ − 249
+ − 250 while (remaining > 0)
+ − 251 {
+ − 252 int this_write = (remaining > sizeof(buf))?sizeof(buf):remaining;
+ − 253 unexec_write (fd, -1, buf, this_write);
+ − 254 remaining -= this_write;
+ − 255 }
+ − 256 }
+ − 257 }
+ − 258
+ − 259 static void
+ − 260 unexec_fstat (int fd, struct stat *statptr)
+ − 261 {
+ − 262 errno = 0;
+ − 263 if (-1 == fstat (fd, statptr))
+ − 264 unexec_error ("fstat() failed for descriptor %d", 1, (char *) fd, 0, 0);
+ − 265 return;
+ − 266 }
+ − 267
+ − 268 static void
+ − 269 unexec_fchmod (int fd, int mode)
+ − 270 {
+ − 271 errno = 0;
+ − 272 if (-1 == fchmod (fd, mode))
+ − 273 unexec_error ("fchmod() failed for descriptor %d", 1, (char *) fd, 0, 0);
+ − 274 return;
+ − 275 }
+ − 276
+ − 277 static long
+ − 278 unexec_addr_to_offset (long addr, struct translation_struct *ts)
+ − 279
+ − 280 {
+ − 281 if ((addr < ts->txtaddr) || (addr >= ts->bssaddr))
+ − 282 unexec_error ("bad address 0x%x to addr_to_offset()",
+ − 283 0, (char *) addr, 0, 0);
+ − 284 if (addr >= ts->dataddr)
+ − 285 return ((long) ((addr - ts->dataddr) + ts->datoff));
+ − 286 else
+ − 287 return ((long) ((addr - ts->txtaddr) + ts->txtoff));
+ − 288 }
+ − 289
+ − 290
+ − 291 /*
+ − 292 * "LD.SO" DATA AND SYMBOL TABLE OPERATIONS
+ − 293 */
+ − 294
+ − 295 static void
+ − 296 copy_relocation_site (struct relocation_info *ri,
+ − 297 caddr_t from_base_addr,
+ − 298 caddr_t to_base_addr,
+ − 299 struct translation_struct *ts)
+ − 300 {
+ − 301 long offset = unexec_addr_to_offset (ri->r_address, ts);
+ − 302 caddr_t from = from_base_addr + offset;
+ − 303 caddr_t to = to_base_addr + offset;
+ − 304
+ − 305 #ifdef mc68020
+ − 306 #define r_type r_length
+ − 307 #endif /* mc68020 */
+ − 308 switch (ri->r_type)
+ − 309 {
+ − 310 #ifdef mc68020
+ − 311 case 0:
+ − 312 *((char *) to) = *((char *) from);
+ − 313 break;
+ − 314 case 1:
+ − 315 *((short *) to) = *((short *) from);
+ − 316 break;
+ − 317 case 2:
+ − 318 *((long *) to) = *((long *) from);
+ − 319 break;
+ − 320 #else /* !mc68020 */
+ − 321 case RELOC_8:
+ − 322 case RELOC_DISP8:
+ − 323 *((char *) to) = *((char *) from);
+ − 324 break;
+ − 325 case RELOC_16:
+ − 326 case RELOC_DISP16:
+ − 327 *((short *) to) = *((short *) from);
+ − 328 break;
+ − 329 case RELOC_LO10:
+ − 330 case RELOC_13:
+ − 331 case RELOC_22:
+ − 332 case RELOC_HI22:
+ − 333 case RELOC_WDISP22:
+ − 334 case RELOC_WDISP30:
+ − 335 case RELOC_32:
+ − 336 case RELOC_DISP32:
+ − 337 case RELOC_GLOB_DAT:
+ − 338 *((long *) to) = *((long *) from);
+ − 339 break;
+ − 340 case RELOC_JMP_SLOT:
+ − 341 {
+ − 342 long *target = (long *) to;
+ − 343 long *source = (long *) from;
+ − 344 *target = *source;
+ − 345 target++;
+ − 346 source++;
+ − 347 *target = *source;
+ − 348 target++;
+ − 349 source++;
+ − 350 *target = *source;
+ − 351 }
+ − 352 break;
+ − 353 #endif /* !mc68020 */
+ − 354 default:
+ − 355 unexec_error ("unknown reloc type %d seen during unexec()",
+ − 356 0, (char *) ri->r_type, 0, 0);
+ − 357 break;
+ − 358 }
+ − 359 return;
+ − 360 }
+ − 361
+ − 362 static void
+ − 363 reset_symtab (struct nlist *start, struct nlist *end, char *strtab,
+ − 364 long edata_value, long end_value, int ld_so_table,
+ − 365 int shlib_image)
+ − 366 {
+ − 367 struct nlist *tmp = start;
+ − 368 int found_edata = 0;
+ − 369 int found_end = 0;
+ − 370
+ − 371 while (tmp < end)
+ − 372 {
+ − 373 int type = tmp->n_type;
+ − 374 int named = (ld_so_table)?1:(tmp->n_un.n_strx);
+ − 375
+ − 376 if ((type == (N_UNDF | N_EXT)) &&
+ − 377 (tmp->n_value != 0))
+ − 378 unexec_error ("unexec'ing image has COMMON symbols in it -- we quit!",
+ − 379 0, 0, 0, 0);
+ − 380
+ − 381 if (!(type & N_STAB))
+ − 382 {
+ − 383 if (!found_edata &&
+ − 384 (type == (N_EXT | N_DATA)) &&
+ − 385 named &&
+ − 386 !strcmp ("_edata", strtab + tmp->n_un.n_strx))
+ − 387 {
+ − 388 tmp->n_value = edata_value;
+ − 389 found_edata = 1;
+ − 390 }
+ − 391
+ − 392
+ − 393 if ((type & N_TYPE) == N_BSS)
+ − 394 {
+ − 395 if (!found_end &&
+ − 396 (type == (N_EXT | N_BSS)) &&
+ − 397 named &&
+ − 398 !strcmp ("_end", strtab + tmp->n_un.n_strx))
+ − 399 {
+ − 400 tmp->n_value = end_value;
+ − 401 found_end = 1;
+ − 402 }
+ − 403 else if (type & N_EXT)
+ − 404 tmp->n_type = N_DATA | N_EXT;
+ − 405 else
+ − 406 tmp->n_type = N_DATA;
+ − 407 }
+ − 408
+ − 409 /* the way things are being handled here, having sbrk() in the
+ − 410 image is fatal for an image linked with shared lib's (although
+ − 411 the code could be modified to support it), but this should
+ − 412 never happen anyway */
+ − 413 if (shlib_image &&
+ − 414 (type == (N_EXT | N_TEXT)) &&
+ − 415 named &&
+ − 416 !strcmp ("_sbrk", strtab + tmp->n_un.n_strx))
+ − 417 unexec_error ("unexec'd shlib image has sbrk() in it -- we quit!",
+ − 418 0, 0, 0, 0);
+ − 419 }
+ − 420
+ − 421 tmp++;
+ − 422 }
+ − 423 }
+ − 424
+ − 425 extern int getpagesize (void);
+ − 426
+ − 427 /*
+ − 428 * EXPORTED FUNCTIONS
+ − 429 */
+ − 430
+ − 431 /* this has to be a global variable to prevent the optimizers from
+ − 432 * assuming that it can not be 0.
+ − 433 */
+ − 434 static void *dynamic_addr = (void *) &_DYNAMIC;
+ − 435
+ − 436 int
+ − 437 unexec (char *new_name, char *old_name,
+ − 438 unsigned int emacs_edata, unsigned int dummy1, unsigned int dummy2)
+ − 439 {
+ − 440 /* ld.so data */
+ − 441 struct link_dynamic *ld = 0;
+ − 442 struct link_dynamic_2 *ld2 = 0;
+ − 443 /* old and new state */
+ − 444 int old_fd;
+ − 445 int new_fd;
+ − 446 caddr_t old_base_addr;
+ − 447 caddr_t new_base_addr;
+ − 448 struct exec old_hdr;
+ − 449 struct exec new_hdr;
+ − 450 struct stat old_buf;
+ − 451 struct stat new_buf;
+ − 452 /* some process specific "constants" */
+ − 453 unsigned long n_pagsiz;
+ − 454 long page_size = getpagesize ();
+ − 455 caddr_t plt_end;
+ − 456 caddr_t current_break = (caddr_t) sbrk (0);
+ − 457
+ − 458 if (!page_size)
+ − 459 unexec_error ("unexec() failed because we can't get the size of a page!",
+ − 460 0, 0, 0, 0);
+ − 461
+ − 462 /* see if this is a -Bdynamic image -- if so, find ld.so structures */
+ − 463 if (dynamic_addr)
+ − 464 {
+ − 465 ld = (struct link_dynamic *) dynamic_addr;
+ − 466 ld2 = ld->ld_un.ld_2;
+ − 467 if (ld->ld_version < 2)
+ − 468 unexec_error ("%s linked with obsolete version of ld -- we quit!",
+ − 469 0, old_name, 0, 0);
+ − 470 }
+ − 471
+ − 472 /* open the old and new files, figuring out how big the old one is
+ − 473 so that we can map it in */
+ − 474 old_fd = unexec_open (old_name, O_RDONLY, 0);
+ − 475 new_fd = unexec_open (new_name, O_RDWR | O_CREAT | O_TRUNC, 0666);
+ − 476
+ − 477 /* setup the header and the statbuf for old_fd */
+ − 478 unexec_read (old_fd, 0, (char *) &old_hdr, sizeof (old_hdr));
+ − 479 unexec_fstat (old_fd, &old_buf);
+ − 480
+ − 481
+ − 482 /* set up some important constants */
+ − 483 n_pagsiz = N_PAGSIZ (old_hdr);
+ − 484 if (dynamic_addr)
+ − 485 plt_end = (caddr_t) MASK_UP (ld2->ld_plt + ld2->ld_plt_sz, sizeof (double));
+ − 486 else
+ − 487 plt_end = (caddr_t) N_DATADDR (old_hdr);
+ − 488
+ − 489 /* never write protect the variable "environ", defined in /lib/crt0.o, and
+ − 490 set in process.c and callproc.c */
+ − 491 mprotect_bottom_addr = ((unsigned long) &environ) + sizeof (char **);
+ − 492 /* never protect ABOVE the end of data emacs_edata specified */
+ − 493 mprotect_top_addr = MIN (emacs_edata, N_DATADDR (old_hdr) + old_hdr.a_data);
+ − 494
+ − 495 /* Set up the image of the old file */
+ − 496 old_base_addr = unexec_mmap (old_fd, old_buf.st_size, PROT_READ, MAP_PRIVATE);
+ − 497 close (old_fd);
+ − 498
+ − 499 /* set up the new exec */
+ − 500 new_hdr = old_hdr;
+ − 501 new_hdr.a_data = (((unsigned long) MASK_UP (current_break, n_pagsiz)) -
+ − 502 ((unsigned long) N_DATADDR (old_hdr)));
+ − 503 new_hdr.a_bss = 0;
+ − 504
+ − 505 /* set up this variable, in case we want to reset "the break"
+ − 506 when restarting */
+ − 507 sbrk_of_0_at_unexec = ((unsigned long) MASK_UP (current_break, n_pagsiz));
+ − 508
+ − 509 /* Write out the first approximation to the new file. The sizes of
+ − 510 each section will be correct, but there will be a number of
+ − 511 corrections that will need to be made. */
+ − 512 {
+ − 513 long old_datoff = N_DATOFF (old_hdr);
+ − 514 long old_dataddr = N_DATADDR (old_hdr);
+ − 515 long new_treloff = N_TRELOFF (new_hdr);
+ − 516 long old_treloff = N_TRELOFF (old_hdr);
+ − 517 long ld_so_size = ((unsigned long) plt_end) - old_dataddr;
+ − 518 long real_data_size = current_break - plt_end;
+ − 519 long pad_size =
+ − 520 MASK_UP (current_break, n_pagsiz) - ((unsigned long) current_break);
+ − 521
+ − 522
+ − 523 /* First, write the text segment with new header -- copy everything until
+ − 524 the start of the data segment from the old file, and then go back and
+ − 525 write the new header. */
+ − 526 unexec_write (new_fd, 0, old_base_addr, old_datoff + ld_so_size);
+ − 527 unexec_write (new_fd, 0, (char *) &new_hdr, sizeof (new_hdr));
+ − 528
+ − 529 /* Copy the rest of the data segment from the running image. */
+ − 530 unexec_write (new_fd, old_datoff + ld_so_size,
+ − 531 plt_end, real_data_size);
+ − 532
+ − 533 /* pad out the data segment */
+ − 534 unexec_pad (new_fd, pad_size);
+ − 535
+ − 536 /* Finally, copy the symbol table information from the old file. */
+ − 537 unexec_write (new_fd, new_treloff,
+ − 538 old_base_addr + old_treloff,
+ − 539 old_buf.st_size - old_treloff);
+ − 540 }
+ − 541
+ − 542
+ − 543 /* Next, map in the output file so that we can jump around fixing it
+ − 544 up. We retain the old file so that we can refer to it. */
+ − 545 unexec_fstat (new_fd, &new_buf);
+ − 546 new_base_addr = unexec_mmap (new_fd,
+ − 547 MASK_UP (new_buf.st_size, page_size),
+ − 548 PROT_READ | PROT_WRITE, MAP_SHARED);
+ − 549
+ − 550
+ − 551
+ − 552 /* We need to do 2 things. First, make sure that _edata and _end (and
+ − 553 hence, curbrk) are set to the correct values. At the same time, for
+ − 554 neatness and to help with debugging, mark all the types of all ld.so
+ − 555 and nm BSS symbols in the new file to be DATA, and make sure that
+ − 556 there are no COMMON symbols in the output file, as any references to
+ − 557 these can lose really big. Second, reset all of the ld.so "relocation
+ − 558 sites" in the new file to have the values that appear in the old file
+ − 559 -- the failure to do this was the biggest loser in the old version of
+ − 560 this code. */
+ − 561
+ − 562 /* STEP 1 */
+ − 563 {
+ − 564 /* Reset the regular symbol table first. */
+ − 565 reset_symtab ((struct nlist *) (new_base_addr + N_SYMOFF(new_hdr)),
+ − 566 (struct nlist *) (new_base_addr + N_SYMOFF(new_hdr) +
+ − 567 new_hdr.a_syms),
+ − 568 (char *) (new_base_addr + N_STROFF(new_hdr)),
+ − 569 N_DATADDR (new_hdr) + new_hdr.a_data,
+ − 570 N_BSSADDR (new_hdr) + new_hdr.a_bss,
+ − 571 0, !!dynamic_addr);
+ − 572 /* Now reset the ld.so symbol table. */
+ − 573 if (dynamic_addr)
+ − 574 reset_symtab ((struct nlist *) (new_base_addr + ld2->ld_stab),
+ − 575 (struct nlist *) (new_base_addr + ld2->ld_symbols),
+ − 576 (char *) (new_base_addr + ld2->ld_symbols),
+ − 577 N_DATADDR (new_hdr) + new_hdr.a_data,
+ − 578 N_BSSADDR (new_hdr) + new_hdr.a_bss,
+ − 579 1, !!dynamic_addr);
+ − 580 }
+ − 581
+ − 582 /* STEP 2 */
+ − 583 if (dynamic_addr)
+ − 584 {
+ − 585 struct translation_struct ts;
+ − 586 struct relocation_info *tmp =
+ − 587 (struct relocation_info *) (old_base_addr + ld2->ld_rel);
+ − 588 struct relocation_info *end =
+ − 589 (struct relocation_info *)(old_base_addr + ld2->ld_hash);
+ − 590
+ − 591 /* set up the structure that we use to translate addresses in the
+ − 592 old file into file offsets */
+ − 593 ts.txtaddr = N_TXTADDR (old_hdr);
+ − 594 ts.txtoff = N_TXTOFF (old_hdr);
+ − 595 ts.dataddr = N_DATADDR (old_hdr);
+ − 596 ts.datoff = N_DATOFF (old_hdr);
+ − 597 ts.bssaddr = N_BSSADDR (old_hdr);
+ − 598
+ − 599 while (tmp < end)
+ − 600 {
+ − 601 copy_relocation_site (tmp, old_base_addr, new_base_addr, &ts);
+ − 602 tmp++;
+ − 603 }
+ − 604 }
+ − 605
+ − 606
+ − 607 /* get rid of the mmap-ed file space and make the output file
+ − 608 executable -- then quit */
+ − 609 munmap (new_base_addr, MASK_UP (new_buf.st_size, page_size));
+ − 610 munmap (old_base_addr, MASK_UP (old_buf.st_size, page_size));
+ − 611 unexec_fchmod (new_fd, 0755);
+ − 612 close (new_fd);
+ − 613 return 0;
+ − 614 }
+ − 615
+ − 616
+ − 617 int
+ − 618 run_time_remap (char *dummy)
+ − 619 {
+ − 620 long page_size = getpagesize();
+ − 621 unsigned long base_addr = MASK_UP (mprotect_bottom_addr, page_size);
+ − 622 unsigned long top_addr = MASK_DOWN (mprotect_top_addr, page_size);
+ − 623 long len = top_addr - base_addr;
+ − 624
+ − 625 if (!dynamic_addr)
+ − 626 {
+ − 627 unsigned long current_sbrk = (unsigned long) sbrk (0);
+ − 628
+ − 629 if (sbrk_of_0_at_unexec < current_sbrk)
+ − 630 {
+ − 631 if (sbrk_of_0_at_unexec != 0)
+ − 632 /* GCC -Wall even catches incorrect printf type errors.
+ − 633 How utterly cool. */
+ − 634 fprintf (stderr,
+ − 635 "Absurd new brk addr = 0x%lx (current = 0x%lx)\n",
+ − 636 sbrk_of_0_at_unexec, current_sbrk);
+ − 637 }
+ − 638 else
+ − 639 {
+ − 640 errno = 0;
+ − 641 if (brk ((caddr_t) sbrk_of_0_at_unexec))
+ − 642 fprintf (stderr, "failed to change brk addr to 0x%lx: %s\n",
+ − 643 sbrk_of_0_at_unexec, SYS_ERR);
+ − 644 }
+ − 645 }
+ − 646
+ − 647 if (len > 0)
+ − 648 {
+ − 649 errno = 0;
+ − 650 if (mprotect ((caddr_t) base_addr, len, PROT_READ | PROT_EXEC))
+ − 651 fprintf (stderr, "failed to change protection on data pages: %s\n",
+ − 652 SYS_ERR);
+ − 653 }
+ − 654
+ − 655 return 0;
+ − 656 }
+ − 657
