1 /* Copyright (C) 1985, 1986, 1987, 1988 Free Software Foundation, Inc. 2 3 This program is free software; you can redistribute it and/or modify 4 it under the terms of the GNU General Public License as published by 5 the Free Software Foundation; either version 1, or (at your option) 6 any later version. 7 8 This program is distributed in the hope that it will be useful, 9 but WITHOUT ANY WARRANTY; without even the implied warranty of 10 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 11 GNU General Public License for more details. 12 13 You should have received a copy of the GNU General Public License 14 along with this program; if not, write to the Free Software 15 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 16 17 In other words, you are welcome to use, share and improve this program. 18 You are forbidden to forbid anyone else to use, share and improve 19 what you give them. Help stamp out software-hoarding! */ 20 21 22 /* 23 * unexec.c - Convert a running program into an a.out file. 24 * 25 * Author: Spencer W. Thomas 26 * Computer Science Dept. 27 * University of Utah 28 * Date: Tue Mar 2 1982 29 * Modified heavily since then. 30 * 31 * Synopsis: 32 * unexec (new_name, a_name, data_start, bss_start, entry_address) 33 * char *new_name, *a_name; 34 * unsigned data_start, bss_start, entry_address; 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 * The boundaries within the a.out file may be adjusted with the data_start 42 * and bss_start arguments. Either or both may be given as 0 for defaults. 43 * 44 * Data_start gives the boundary between the text segment and the data 45 * segment of the program. The text segment can contain shared, read-only 46 * program code and literal data, while the data segment is always unshared 47 * and unprotected. Data_start gives the lowest unprotected address. 48 * The value you specify may be rounded down to a suitable boundary 49 * as required by the machine you are using. 50 * 51 * Specifying zero for data_start means the boundary between text and data 52 * should not be the same as when the program was loaded. 53 * If NO_REMAP is defined, the argument data_start is ignored and the 54 * segment boundaries are never changed. 55 * 56 * Bss_start indicates how much of the data segment is to be saved in the 57 * a.out file and restored when the program is executed. It gives the lowest 58 * unsaved address, and is rounded up to a page boundary. The default when 0 59 * is given assumes that the entire data segment is to be stored, including 60 * the previous data and bss as well as any additional storage allocated with 61 * break (2). 62 * 63 * The new file is set up to start at entry_address. 64 * 65 * If you make improvements I'd like to get them too. 66 * harpo!utah-cs!thomas, thomas@Utah-20 67 * 68 */ 69 70 /* Modified to support SysVr3 shared libraries by James Van Artsdalen 71 * of Dell Computer Corporation. james@bigtex.cactus.org. 72 */ 73 74 /* There are several compilation parameters affecting unexec: 75 76 * COFF 77 78 Define this if your system uses COFF for executables. 79 Otherwise we assume you use Berkeley format. 80 81 * NO_REMAP 82 83 Define this if you do not want to try to save Emacs's pure data areas 84 as part of the text segment. 85 86 Saving them as text is good because it allows users to share more. 87 88 However, on machines that locate the text area far from the data area, 89 the boundary cannot feasibly be moved. Such machines require 90 NO_REMAP. 91 92 Also, remapping can cause trouble with the built-in startup routine 93 /lib/crt0.o, which defines `environ' as an initialized variable. 94 Dumping `environ' as pure does not work! So, to use remapping, 95 you must write a startup routine for your machine in Emacs's crt0.c. 96 If NO_REMAP is defined, Emacs uses the system's crt0.o. 97 98 * SECTION_ALIGNMENT 99 100 Some machines that use COFF executables require that each section 101 start on a certain boundary *in the COFF file*. Such machines should 102 define SECTION_ALIGNMENT to a mask of the low-order bits that must be 103 zero on such a boundary. This mask is used to control padding between 104 segments in the COFF file. 105 106 If SECTION_ALIGNMENT is not defined, the segments are written 107 consecutively with no attempt at alignment. This is right for 108 unmodified system V. 109 110 * SEGMENT_MASK 111 112 Some machines require that the beginnings and ends of segments 113 *in core* be on certain boundaries. For most machines, a page 114 boundary is sufficient. That is the default. When a larger 115 boundary is needed, define SEGMENT_MASK to a mask of 116 the bits that must be zero on such a boundary. 117 118 * A_TEXT_OFFSET(HDR) 119 120 Some machines count the a.out header as part of the size of the text 121 segment (a_text); they may actually load the header into core as the 122 first data in the text segment. Some have additional padding between 123 the header and the real text of the program that is counted in a_text. 124 125 For these machines, define A_TEXT_OFFSET(HDR) to examine the header 126 structure HDR and return the number of bytes to add to `a_text' 127 before writing it (above and beyond the number of bytes of actual 128 program text). HDR's standard fields are already correct, except that 129 this adjustment to the `a_text' field has not yet been made; 130 thus, the amount of offset can depend on the data in the file. 131 132 * A_TEXT_SEEK(HDR) 133 134 If defined, this macro specifies the number of bytes to seek into the 135 a.out file before starting to write the text segment.a 136 137 * EXEC_MAGIC 138 139 For machines using COFF, this macro, if defined, is a value stored 140 into the magic number field of the output file. 141 142 * ADJUST_EXEC_HEADER 143 144 This macro can be used to generate statements to adjust or 145 initialize nonstandard fields in the file header 146 147 * ADDR_CORRECT(ADDR) 148 149 Macro to correct an int which is the bit pattern of a pointer to a byte 150 into an int which is the number of a byte. 151 152 This macro has a default definition which is usually right. 153 This default definition is a no-op on most machines (where a 154 pointer looks like an int) but not on all machines. 155 156 */ 157 158 #ifndef emacs 159 #define PERROR(arg) perror (arg); return -1 160 #else 161 #include "config.h" 162 #define PERROR(file) report_error (file, new) 163 #endif 164 165 #ifndef CANNOT_DUMP /* all rest of file! */ 166 167 #ifndef CANNOT_UNEXEC /* most of rest of file */ 168 169 #include <a.out.h> 170 /* Define getpagesize () if the system does not. 171 Note that this may depend on symbols defined in a.out.h 172 */ 173 #include "getpagesize.h" 174 175 #ifndef makedev /* Try to detect types.h already loaded */ 176 #include <sys/types.h> 177 #endif 178 #include <stdio.h> 179 #include <sys/stat.h> 180 #include <errno.h> 181 182 extern char *start_of_text (); /* Start of text */ 183 extern char *start_of_data (); /* Start of initialized data */ 184 185 #ifdef COFF 186 #ifndef USG 187 #ifndef STRIDE 188 #ifndef UMAX 189 #ifndef sun386 190 /* I have a suspicion that these are turned off on all systems 191 and can be deleted. Try it in version 19. */ 192 #include <filehdr.h> 193 #include <aouthdr.h> 194 #include <scnhdr.h> 195 #include <syms.h> 196 #endif /* not sun386 */ 197 #endif /* not UMAX */ 198 #endif /* Not STRIDE */ 199 #endif /* not USG */ 200 static long block_copy_start; /* Old executable start point */ 201 static struct filehdr f_hdr; /* File header */ 202 static struct aouthdr f_ohdr; /* Optional file header (a.out) */ 203 long bias; /* Bias to add for growth */ 204 long lnnoptr; /* Pointer to line-number info within file */ 205 #define SYMS_START block_copy_start 206 207 static long text_scnptr; 208 static long data_scnptr; 209 210 #else /* not COFF */ 211 212 extern char *sbrk (); 213 214 #define SYMS_START ((long) N_SYMOFF (ohdr)) 215 216 /* Some machines override the structure name for an a.out header. */ 217 #ifndef EXEC_HDR_TYPE 218 #define EXEC_HDR_TYPE struct exec 219 #endif 220 221 #ifdef HPUX 222 #ifdef HP9000S200_ID 223 #define MY_ID HP9000S200_ID 224 #else 225 #include <model.h> 226 #define MY_ID MYSYS 227 #endif /* no HP9000S200_ID */ 228 static MAGIC OLDMAGIC = {MY_ID, SHARE_MAGIC}; 229 static MAGIC NEWMAGIC = {MY_ID, DEMAND_MAGIC}; 230 #define N_TXTOFF(x) TEXT_OFFSET(x) 231 #define N_SYMOFF(x) LESYM_OFFSET(x) 232 static EXEC_HDR_TYPE hdr, ohdr; 233 234 #else /* not HPUX */ 235 236 #if defined (USG) && !defined (IBMRTAIX) && !defined (IRIS) 237 static struct bhdr hdr, ohdr; 238 #define a_magic fmagic 239 #define a_text tsize 240 #define a_data dsize 241 #define a_bss bsize 242 #define a_syms ssize 243 #define a_trsize rtsize 244 #define a_drsize rdsize 245 #define a_entry entry 246 #define N_BADMAG(x) \ 247 (((x).fmagic)!=OMAGIC && ((x).fmagic)!=NMAGIC &&\ 248 ((x).fmagic)!=FMAGIC && ((x).fmagic)!=IMAGIC) 249 #define NEWMAGIC FMAGIC 250 #else /* IRIS or IBMRTAIX or not USG */ 251 static EXEC_HDR_TYPE hdr, ohdr; 252 #define NEWMAGIC ZMAGIC 253 #endif /* IRIS or IBMRTAIX not USG */ 254 #endif /* not HPUX */ 255 256 static int unexec_text_start; 257 static int unexec_data_start; 258 259 #endif /* not COFF */ 260 261 static int pagemask; 262 263 /* Correct an int which is the bit pattern of a pointer to a byte 264 into an int which is the number of a byte. 265 This is a no-op on ordinary machines, but not on all. */ 266 267 #ifndef ADDR_CORRECT /* Let m-*.h files override this definition */ 268 #define ADDR_CORRECT(x) ((char *)(x) - (char*)0) 269 #endif 270 271 #ifdef emacs 272 273 static 274 report_error (file, fd) 275 char *file; 276 int fd; 277 { 278 if (fd) 279 close (fd); 280 error ("Failure operating on %s", file); 281 } 282 #endif /* emacs */ 283 284 #define ERROR0(msg) report_error_1 (new, msg, 0, 0); return -1 285 #define ERROR1(msg,x) report_error_1 (new, msg, x, 0); return -1 286 #define ERROR2(msg,x,y) report_error_1 (new, msg, x, y); return -1 287 288 static 289 report_error_1 (fd, msg, a1, a2) 290 int fd; 291 char *msg; 292 int a1, a2; 293 { 294 close (fd); 295 #ifdef emacs 296 error (msg, a1, a2); 297 #else 298 fprintf (stderr, msg, a1, a2); 299 fprintf (stderr, "\n"); 300 #endif 301 } 302 303 /* **************************************************************** 304 * unexec 305 * 306 * driving logic. 307 */ 308 unexec (new_name, a_name, data_start, bss_start, entry_address) 309 char *new_name, *a_name; 310 unsigned data_start, bss_start, entry_address; 311 { 312 int new, a_out = -1; 313 314 if (a_name && (a_out = open (a_name, 0)) < 0) 315 { 316 PERROR (a_name); 317 } 318 if ((new = creat (new_name, 0666)) < 0) 319 { 320 PERROR (new_name); 321 } 322 323 if (make_hdr (new, a_out, data_start, bss_start, entry_address, a_name, new_name) < 0 324 || copy_text_and_data (new, a_out) < 0 325 || copy_sym (new, a_out, a_name, new_name) < 0 326 #ifdef COFF 327 || adjust_lnnoptrs (new, a_out, new_name) < 0 328 #endif 329 ) 330 { 331 close (new); 332 /* unlink (new_name); /* Failed, unlink new a.out */ 333 return -1; 334 } 335 336 close (new); 337 if (a_out >= 0) 338 close (a_out); 339 mark_x (new_name); 340 return 0; 341 } 342 343 /* **************************************************************** 344 * make_hdr 345 * 346 * Make the header in the new a.out from the header in core. 347 * Modify the text and data sizes. 348 */ 349 static int 350 make_hdr (new, a_out, data_start, bss_start, entry_address, a_name, new_name) 351 int new, a_out; 352 unsigned data_start, bss_start, entry_address; 353 char *a_name; 354 char *new_name; 355 { 356 int tem; 357 #ifdef COFF 358 auto struct scnhdr f_thdr; /* Text section header */ 359 auto struct scnhdr f_dhdr; /* Data section header */ 360 auto struct scnhdr f_bhdr; /* Bss section header */ 361 auto struct scnhdr scntemp; /* Temporary section header */ 362 register int scns; 363 #endif /* COFF */ 364 #ifdef USG_SHARED_LIBRARIES 365 extern unsigned int bss_end; 366 #else 367 unsigned int bss_end; 368 #endif 369 370 pagemask = getpagesize () - 1; 371 372 /* Adjust text/data boundary. */ 373 #ifdef NO_REMAP 374 data_start = (int) start_of_data (); 375 #else /* not NO_REMAP */ 376 if (!data_start) 377 data_start = (int) start_of_data (); 378 #endif /* not NO_REMAP */ 379 data_start = ADDR_CORRECT (data_start); 380 381 #ifdef SEGMENT_MASK 382 data_start = data_start & ~SEGMENT_MASK; /* (Down) to segment boundary. */ 383 #else 384 data_start = data_start & ~pagemask; /* (Down) to page boundary. */ 385 #endif 386 387 bss_end = ADDR_CORRECT (sbrk (0)) + pagemask; 388 bss_end &= ~ pagemask; 389 390 /* Adjust data/bss boundary. */ 391 if (bss_start != 0) 392 { 393 bss_start = (ADDR_CORRECT (bss_start) + pagemask); 394 /* (Up) to page bdry. */ 395 bss_start &= ~ pagemask; 396 if (bss_start > bss_end) 397 { 398 ERROR1 ("unexec: Specified bss_start (%u) is past end of program", 399 bss_start); 400 } 401 } 402 else 403 bss_start = bss_end; 404 405 if (data_start > bss_start) /* Can't have negative data size. */ 406 { 407 ERROR2 ("unexec: data_start (%u) can't be greater than bss_start (%u)", 408 data_start, bss_start); 409 } 410 411 #ifdef COFF 412 /* Salvage as much info from the existing file as possible */ 413 if (a_out >= 0) 414 { 415 if (read (a_out, &f_hdr, sizeof (f_hdr)) != sizeof (f_hdr)) 416 { 417 PERROR (a_name); 418 } 419 block_copy_start += sizeof (f_hdr); 420 if (f_hdr.f_opthdr > 0) 421 { 422 if (read (a_out, &f_ohdr, sizeof (f_ohdr)) != sizeof (f_ohdr)) 423 { 424 PERROR (a_name); 425 } 426 block_copy_start += sizeof (f_ohdr); 427 } 428 /* Loop through section headers, copying them in */ 429 for (scns = f_hdr.f_nscns; scns > 0; scns--) { 430 if (read (a_out, &scntemp, sizeof (scntemp)) != sizeof (scntemp)) 431 { 432 PERROR (a_name); 433 } 434 if (scntemp.s_scnptr > 0L) 435 { 436 if (block_copy_start < scntemp.s_scnptr + scntemp.s_size) 437 block_copy_start = scntemp.s_scnptr + scntemp.s_size; 438 } 439 if (strcmp (scntemp.s_name, ".text") == 0) 440 { 441 f_thdr = scntemp; 442 } 443 else if (strcmp (scntemp.s_name, ".data") == 0) 444 { 445 f_dhdr = scntemp; 446 } 447 else if (strcmp (scntemp.s_name, ".bss") == 0) 448 { 449 f_bhdr = scntemp; 450 } 451 } 452 } 453 else 454 { 455 ERROR0 ("can't build a COFF file from scratch yet"); 456 } 457 458 /* Now we alter the contents of all the f_*hdr variables 459 to correspond to what we want to dump. */ 460 461 #ifdef USG_SHARED_LIBRARIES 462 463 /* The amount of data we're adding to the file is distance from the 464 * end of the original .data space to the current end of the .data 465 * space. 466 */ 467 468 bias = bss_end - (f_ohdr.data_start + f_dhdr.s_size); 469 470 #endif 471 472 f_hdr.f_flags |= (F_RELFLG | F_EXEC); 473 #ifdef EXEC_MAGIC 474 f_ohdr.magic = EXEC_MAGIC; 475 #endif 476 #ifndef NO_REMAP 477 f_ohdr.text_start = (long) start_of_text (); 478 f_ohdr.tsize = data_start - f_ohdr.text_start; 479 f_ohdr.data_start = data_start; 480 #endif /* NO_REMAP */ 481 f_ohdr.dsize = bss_start - f_ohdr.data_start; 482 f_ohdr.bsize = bss_end - bss_start; 483 f_thdr.s_size = f_ohdr.tsize; 484 f_thdr.s_scnptr = sizeof (f_hdr) + sizeof (f_ohdr); 485 f_thdr.s_scnptr += (f_hdr.f_nscns) * (sizeof (f_thdr)); 486 lnnoptr = f_thdr.s_lnnoptr; 487 #ifdef SECTION_ALIGNMENT 488 /* Some systems require special alignment 489 of the sections in the file itself. */ 490 f_thdr.s_scnptr 491 = (f_thdr.s_scnptr + SECTION_ALIGNMENT) & ~SECTION_ALIGNMENT; 492 #endif /* SECTION_ALIGNMENT */ 493 text_scnptr = f_thdr.s_scnptr; 494 f_dhdr.s_paddr = f_ohdr.data_start; 495 f_dhdr.s_vaddr = f_ohdr.data_start; 496 f_dhdr.s_size = f_ohdr.dsize; 497 f_dhdr.s_scnptr = f_thdr.s_scnptr + f_thdr.s_size; 498 #ifdef SECTION_ALIGNMENT 499 /* Some systems require special alignment 500 of the sections in the file itself. */ 501 f_dhdr.s_scnptr 502 = (f_dhdr.s_scnptr + SECTION_ALIGNMENT) & ~SECTION_ALIGNMENT; 503 #endif /* SECTION_ALIGNMENT */ 504 #ifdef DATA_SECTION_ALIGNMENT 505 /* Some systems require special alignment 506 of the data section only. */ 507 f_dhdr.s_scnptr 508 = (f_dhdr.s_scnptr + DATA_SECTION_ALIGNMENT) & ~DATA_SECTION_ALIGNMENT; 509 #endif /* DATA_SECTION_ALIGNMENT */ 510 data_scnptr = f_dhdr.s_scnptr; 511 f_bhdr.s_paddr = f_ohdr.data_start + f_ohdr.dsize; 512 f_bhdr.s_vaddr = f_ohdr.data_start + f_ohdr.dsize; 513 f_bhdr.s_size = f_ohdr.bsize; 514 f_bhdr.s_scnptr = 0L; 515 #ifndef USG_SHARED_LIBRARIES 516 bias = f_dhdr.s_scnptr + f_dhdr.s_size - block_copy_start; 517 #endif 518 519 if (f_hdr.f_symptr > 0L) 520 { 521 f_hdr.f_symptr += bias; 522 } 523 524 if (f_thdr.s_lnnoptr > 0L) 525 { 526 f_thdr.s_lnnoptr += bias; 527 } 528 529 #ifdef ADJUST_EXEC_HEADER 530 ADJUST_EXEC_HEADER 531 #endif /* ADJUST_EXEC_HEADER */ 532 533 if (write (new, &f_hdr, sizeof (f_hdr)) != sizeof (f_hdr)) 534 { 535 PERROR (new_name); 536 } 537 538 if (write (new, &f_ohdr, sizeof (f_ohdr)) != sizeof (f_ohdr)) 539 { 540 PERROR (new_name); 541 } 542 543 #ifndef USG_SHARED_LIBRARIES 544 545 if (write (new, &f_thdr, sizeof (f_thdr)) != sizeof (f_thdr)) 546 { 547 PERROR (new_name); 548 } 549 550 if (write (new, &f_dhdr, sizeof (f_dhdr)) != sizeof (f_dhdr)) 551 { 552 PERROR (new_name); 553 } 554 555 if (write (new, &f_bhdr, sizeof (f_bhdr)) != sizeof (f_bhdr)) 556 { 557 PERROR (new_name); 558 } 559 560 #else /* USG_SHARED_LIBRARIES */ 561 562 /* The purpose of this code is to write out the new file's section 563 * header table. 564 * 565 * Scan through the original file's sections. If the encountered 566 * section is one we know (.text, .data or .bss), write out the 567 * correct header. If it is a section we do not know (such as 568 * .lib), adjust the address of where the section data is in the 569 * file, and write out the header. 570 * 571 * If any section preceeds .text or .data in the file, this code 572 * will not adjust the file pointer for that section correctly. 573 */ 574 575 lseek (a_out, (off_t) sizeof (f_hdr) + sizeof (f_ohdr), 0); 576 577 for (scns = f_hdr.f_nscns; scns > 0; scns--) 578 { 579 if (read (a_out, &scntemp, sizeof (scntemp)) != sizeof (scntemp)) 580 PERROR (a_name); 581 582 if (!strcmp (scntemp.s_name, f_thdr.s_name)) /* .text */ 583 { 584 if (write (new, &f_thdr, sizeof (f_thdr)) != sizeof (f_thdr)) 585 PERROR (new_name); 586 } 587 else if (!strcmp (scntemp.s_name, f_dhdr.s_name)) /* .data */ 588 { 589 if (write (new, &f_dhdr, sizeof (f_dhdr)) != sizeof (f_dhdr)) 590 PERROR (new_name); 591 } 592 else if (!strcmp (scntemp.s_name, f_bhdr.s_name)) /* .bss */ 593 { 594 if (write (new, &f_bhdr, sizeof (f_bhdr)) != sizeof (f_bhdr)) 595 PERROR (new_name); 596 } 597 else 598 { 599 if (scntemp.s_scnptr) 600 scntemp.s_scnptr += bias; 601 if (write (new, &scntemp, sizeof (scntemp)) != sizeof (scntemp)) 602 PERROR (new_name); 603 } 604 } 605 #endif /* USG_SHARED_LIBRARIES */ 606 607 return (0); 608 609 #else /* if not COFF */ 610 611 /* Get symbol table info from header of a.out file if given one. */ 612 if (a_out >= 0) 613 { 614 if (read (a_out, &ohdr, sizeof hdr) != sizeof hdr) 615 { 616 PERROR (a_name); 617 } 618 619 if (N_BADMAG (ohdr)) 620 { 621 ERROR1 ("invalid magic number in %s", a_name); 622 } 623 hdr = ohdr; 624 } 625 else 626 { 627 bzero (hdr, sizeof hdr); 628 } 629 630 unexec_text_start = (long) start_of_text (); 631 unexec_data_start = data_start; 632 633 /* Machine-dependent fixup for header, or maybe for unexec_text_start */ 634 #ifdef ADJUST_EXEC_HEADER 635 ADJUST_EXEC_HEADER; 636 #endif /* ADJUST_EXEC_HEADER */ 637 638 hdr.a_trsize = 0; 639 hdr.a_drsize = 0; 640 if (entry_address != 0) 641 hdr.a_entry = entry_address; 642 643 hdr.a_bss = bss_end - bss_start; 644 hdr.a_data = bss_start - data_start; 645 #ifdef NO_REMAP 646 hdr.a_text = ohdr.a_text; 647 #else /* not NO_REMAP */ 648 hdr.a_text = data_start - unexec_text_start; 649 650 #ifdef A_TEXT_OFFSET 651 hdr.a_text += A_TEXT_OFFSET (ohdr); 652 #endif 653 654 #endif /* not NO_REMAP */ 655 656 if (write (new, &hdr, sizeof hdr) != sizeof hdr) 657 { 658 PERROR (new_name); 659 } 660 661 #ifdef A_TEXT_OFFSET 662 hdr.a_text -= A_TEXT_OFFSET (ohdr); 663 #endif 664 665 return 0; 666 667 #endif /* not COFF */ 668 } 669 670 /* **************************************************************** 671 * copy_text_and_data 672 * 673 * Copy the text and data segments from memory to the new a.out 674 */ 675 static int 676 copy_text_and_data (new, a_out) 677 int new, a_out; 678 { 679 register char *end; 680 register char *ptr; 681 682 #ifdef COFF 683 684 #ifdef USG_SHARED_LIBRARIES 685 686 int scns; 687 struct scnhdr scntemp; /* Temporary section header */ 688 689 /* The purpose of this code is to write out the new file's section 690 * contents. 691 * 692 * Step through the section table. If we know the section (.text, 693 * .data) do the appropriate thing. Otherwise, if the section has 694 * no allocated space in the file (.bss), do nothing. Otherwise, 695 * the section has space allocated in the file, and is not a section 696 * we know. So just copy it. 697 */ 698 699 lseek (a_out, (off_t) sizeof (struct filehdr) + sizeof (struct aouthdr), 0); 700 701 for (scns = f_hdr.f_nscns; scns > 0; scns--) 702 { 703 if (read (a_out, &scntemp, sizeof (scntemp)) != sizeof (scntemp)) 704 PERROR ("temacs"); 705 706 if (!strcmp (scntemp.s_name, ".text")) 707 { 708 lseek (new, (off_t) text_scnptr, 0); 709 ptr = (char *) f_ohdr.text_start; 710 end = ptr + f_ohdr.tsize; 711 write_segment (new, ptr, end); 712 } 713 else if (!strcmp (scntemp.s_name, ".data")) 714 { 715 lseek (new, (off_t) data_scnptr, 0); 716 ptr = (char *) f_ohdr.data_start; 717 end = ptr + f_ohdr.dsize; 718 write_segment (new, ptr, end); 719 } 720 else if (!scntemp.s_scnptr) 721 ; /* do nothing - no data for this section */ 722 else 723 { 724 char page[BUFSIZ]; 725 int size, n; 726 long old_a_out_ptr = lseek (a_out, (off_t) 0, 1); 727 728 lseek (a_out, (off_t) scntemp.s_scnptr, 0); 729 for (size = scntemp.s_size; size > 0; size -= sizeof (page)) 730 { 731 n = size > sizeof (page) ? sizeof (page) : size; 732 if (read (a_out, page, n) != n || write (new, page, n) != n) 733 PERROR ("xemacs"); 734 } 735 lseek (a_out, (off_t) old_a_out_ptr, 0); 736 } 737 } 738 739 #else /* COFF, but not USG_SHARED_LIBRARIES */ 740 741 lseek (new, (off_t) text_scnptr, 0); 742 ptr = (char *) f_ohdr.text_start; 743 end = ptr + f_ohdr.tsize; 744 write_segment (new, ptr, end); 745 746 lseek (new, (off_t) data_scnptr, 0); 747 ptr = (char *) f_ohdr.data_start; 748 end = ptr + f_ohdr.dsize; 749 write_segment (new, ptr, end); 750 751 #endif /* USG_SHARED_LIBRARIES */ 752 753 #else /* if not COFF */ 754 755 /* Some machines count the header as part of the text segment. 756 That is to say, the header appears in core 757 just before the address that start_of_text () returns. 758 For them, N_TXTOFF is the place where the header goes. 759 We must adjust the seek to the place after the header. 760 Note that at this point hdr.a_text does *not* count 761 the extra A_TEXT_OFFSET bytes, only the actual bytes of code. */ 762 763 #ifdef A_TEXT_SEEK 764 lseek (new, (off_t) A_TEXT_SEEK (hdr), 0); 765 #else 766 #ifdef A_TEXT_OFFSET 767 /* Note that on the Sequent machine A_TEXT_OFFSET != sizeof (hdr) 768 and sizeof (hdr) is the correct amount to add here. */ 769 /* In version 19, eliminate this case and use A_TEXT_SEEK whenever 770 N_TXTOFF is not right. */ 771 lseek (new, (off_t) N_TXTOFF (hdr) + sizeof (hdr), 0); 772 #else 773 lseek (new, (off_t) N_TXTOFF (hdr), 0); 774 #endif /* no A_TEXT_OFFSET */ 775 #endif /* no A_TEXT_SEEK */ 776 777 ptr = (char *) unexec_text_start; 778 end = ptr + hdr.a_text; 779 write_segment (new, ptr, end); 780 781 ptr = (char *) unexec_data_start; 782 end = ptr + hdr.a_data; 783 /* This lseek is certainly incorrect when A_TEXT_OFFSET 784 and I believe it is a no-op otherwise. 785 Let's see if its absence ever fails. */ 786 /* lseek (new, (off_t) N_TXTOFF (hdr) + hdr.a_text, 0); */ 787 write_segment (new, ptr, end); 788 789 #endif /* not COFF */ 790 791 return 0; 792 } 793 794 write_segment (new, ptr, end) 795 int new; 796 register char *ptr, *end; 797 { 798 register int i, nwrite, ret; 799 char buf[80]; 800 extern int errno; 801 char zeros[128]; 802 803 bzero (zeros, sizeof zeros); 804 805 for (i = 0; ptr < end;) 806 { 807 /* distance to next multiple of 128. */ 808 nwrite = (((int) ptr + 128) & -128) - (int) ptr; 809 /* But not beyond specified end. */ 810 if (nwrite > end - ptr) nwrite = end - ptr; 811 ret = write (new, ptr, nwrite); 812 /* If write gets a page fault, it means we reached 813 a gap between the old text segment and the old data segment. 814 This gap has probably been remapped into part of the text segment. 815 So write zeros for it. */ 816 if (ret == -1 && errno == EFAULT) 817 write (new, zeros, nwrite); 818 else if (nwrite != ret) 819 { 820 sprintf (buf, 821 "unexec write failure: addr 0x%x, fileno %d, size 0x%x, wrote 0x%x, errno %d", 822 ptr, new, nwrite, ret, errno); 823 PERROR (buf); 824 } 825 i += nwrite; 826 ptr += nwrite; 827 } 828 } 829 830 /* **************************************************************** 831 * copy_sym 832 * 833 * Copy the relocation information and symbol table from the a.out to the new 834 */ 835 static int 836 copy_sym (new, a_out, a_name, new_name) 837 int new, a_out; 838 char *a_name, *new_name; 839 { 840 char page[1024]; 841 int n; 842 843 if (a_out < 0) 844 return 0; 845 846 #ifdef COFF 847 if (SYMS_START == 0L) 848 return 0; 849 #endif /* COFF */ 850 851 #ifdef COFF 852 if (lnnoptr) /* if there is line number info */ 853 lseek (a_out, (off_t) lnnoptr, 0); /* start copying from there */ 854 else 855 #endif /* COFF */ 856 lseek (a_out, (off_t) SYMS_START, 0); /* Position a.out to symtab. */ 857 858 while ((n = read (a_out, page, sizeof page)) > 0) 859 { 860 if (write (new, page, n) != n) 861 { 862 PERROR (new_name); 863 } 864 } 865 if (n < 0) 866 { 867 PERROR (a_name); 868 } 869 return 0; 870 } 871 872 /* **************************************************************** 873 * mark_x 874 * 875 * After succesfully building the new a.out, mark it executable 876 */ 877 static 878 mark_x (name) 879 char *name; 880 { 881 struct stat sbuf; 882 int um; 883 int new = 0; /* for PERROR */ 884 885 um = umask (777); 886 umask (um); 887 if (stat (name, &sbuf) == -1) 888 { 889 PERROR (name); 890 } 891 sbuf.st_mode |= 0111 & ~um; 892 if (chmod (name, sbuf.st_mode) == -1) 893 PERROR (name); 894 } 895 896 /* 897 * If the COFF file contains a symbol table and a line number section, 898 * then any auxiliary entries that have values for x_lnnoptr must 899 * be adjusted by the amount that the line number section has moved 900 * in the file (bias computed in make_hdr). The #@$%&* designers of 901 * the auxiliary entry structures used the absolute file offsets for 902 * the line number entry rather than an offset from the start of the 903 * line number section! 904 * 905 * When I figure out how to scan through the symbol table and pick out 906 * the auxiliary entries that need adjustment, this routine will 907 * be fixed. As it is now, all such entries are wrong and sdb 908 * will complain. Fred Fish, UniSoft Systems Inc. 909 */ 910 911 #ifdef COFF 912 913 /* This function is probably very slow. Instead of reopening the new 914 file for input and output it should copy from the old to the new 915 using the two descriptors already open (WRITEDESC and READDESC). 916 Instead of reading one small structure at a time it should use 917 a reasonable size buffer. But I don't have time to work on such 918 things, so I am installing it as submitted to me. -- RMS. */ 919 920 adjust_lnnoptrs (writedesc, readdesc, new_name) 921 int writedesc; 922 int readdesc; 923 char *new_name; 924 { 925 register int nsyms; 926 register int new; 927 #ifdef amdahl_uts 928 SYMENT symentry; 929 AUXENT auxentry; 930 #else 931 struct syment symentry; 932 union auxent auxentry; 933 #endif 934 935 if (!lnnoptr || !f_hdr.f_symptr) 936 return 0; 937 938 if ((new = open (new_name, 2)) < 0) 939 { 940 PERROR (new_name); 941 return -1; 942 } 943 944 lseek (new, (off_t) f_hdr.f_symptr, 0); 945 for (nsyms = 0; nsyms < f_hdr.f_nsyms; nsyms++) 946 { 947 read (new, &symentry, SYMESZ); 948 if (symentry.n_numaux) 949 { 950 read (new, &auxentry, AUXESZ); 951 nsyms++; 952 if (ISFCN (symentry.n_type)) { 953 auxentry.x_sym.x_fcnary.x_fcn.x_lnnoptr += bias; 954 lseek (new, (off_t) -AUXESZ, 1); 955 write (new, &auxentry, AUXESZ); 956 } 957 } 958 } 959 close (new); 960 } 961 962 #endif /* COFF */ 963 964 #endif /* not CANNOT_UNEXEC */ 965 966 #endif /* not CANNOT_DUMP */ 967