unexaix.c 22.7 KB
Newer Older
Jim Blandy's avatar
Jim Blandy committed
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153
/* Modified by Andrew.Vignaux@comp.vuw.ac.nz to get it to work :-) */

/* Copyright (C) 1985, 1986, 1987, 1988 Free Software Foundation, Inc.

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 1, or (at your option)
    any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

In other words, you are welcome to use, share and improve this program.
You are forbidden to forbid anyone else to use, share and improve
what you give them.   Help stamp out software-hoarding!  */


/*
 * unexec.c - Convert a running program into an a.out file.
 *
 * Author:	Spencer W. Thomas
 * 		Computer Science Dept.
 * 		University of Utah
 * Date:	Tue Mar  2 1982
 * Modified heavily since then.
 *
 * Synopsis:
 *	unexec (new_name, a_name, data_start, bss_start, entry_address)
 *	char *new_name, *a_name;
 *	unsigned data_start, bss_start, entry_address;
 *
 * Takes a snapshot of the program and makes an a.out format file in the
 * file named by the string argument new_name.
 * If a_name is non-NULL, the symbol table will be taken from the given file.
 * On some machines, an existing a_name file is required.
 *
 * The boundaries within the a.out file may be adjusted with the data_start
 * and bss_start arguments.  Either or both may be given as 0 for defaults.
 *
 * Data_start gives the boundary between the text segment and the data
 * segment of the program.  The text segment can contain shared, read-only
 * program code and literal data, while the data segment is always unshared
 * and unprotected.  Data_start gives the lowest unprotected address.
 * The value you specify may be rounded down to a suitable boundary
 * as required by the machine you are using.
 *
 * Specifying zero for data_start means the boundary between text and data
 * should not be the same as when the program was loaded.
 * If NO_REMAP is defined, the argument data_start is ignored and the
 * segment boundaries are never changed.
 *
 * Bss_start indicates how much of the data segment is to be saved in the
 * a.out file and restored when the program is executed.  It gives the lowest
 * unsaved address, and is rounded up to a page boundary.  The default when 0
 * is given assumes that the entire data segment is to be stored, including
 * the previous data and bss as well as any additional storage allocated with
 * break (2).
 *
 * The new file is set up to start at entry_address.
 *
 * If you make improvements I'd like to get them too.
 * harpo!utah-cs!thomas, thomas@Utah-20
 *
 */

/* There are several compilation parameters affecting unexec:

* COFF

Define this if your system uses COFF for executables.
Otherwise we assume you use Berkeley format.

* NO_REMAP

Define this if you do not want to try to save Emacs's pure data areas
as part of the text segment.

Saving them as text is good because it allows users to share more.

However, on machines that locate the text area far from the data area,
the boundary cannot feasibly be moved.  Such machines require
NO_REMAP.

Also, remapping can cause trouble with the built-in startup routine
/lib/crt0.o, which defines `environ' as an initialized variable.
Dumping `environ' as pure does not work!  So, to use remapping,
you must write a startup routine for your machine in Emacs's crt0.c.
If NO_REMAP is defined, Emacs uses the system's crt0.o.

* SECTION_ALIGNMENT

Some machines that use COFF executables require that each section
start on a certain boundary *in the COFF file*.  Such machines should
define SECTION_ALIGNMENT to a mask of the low-order bits that must be
zero on such a boundary.  This mask is used to control padding between
segments in the COFF file.

If SECTION_ALIGNMENT is not defined, the segments are written
consecutively with no attempt at alignment.  This is right for
unmodified system V.

* SEGMENT_MASK

Some machines require that the beginnings and ends of segments
*in core* be on certain boundaries.  For most machines, a page
boundary is sufficient.  That is the default.  When a larger
boundary is needed, define SEGMENT_MASK to a mask of
the bits that must be zero on such a boundary.

* A_TEXT_OFFSET(HDR)

Some machines count the a.out header as part of the size of the text
segment (a_text); they may actually load the header into core as the
first data in the text segment.  Some have additional padding between
the header and the real text of the program that is counted in a_text.

For these machines, define A_TEXT_OFFSET(HDR) to examine the header
structure HDR and return the number of bytes to add to `a_text'
before writing it (above and beyond the number of bytes of actual
program text).  HDR's standard fields are already correct, except that
this adjustment to the `a_text' field has not yet been made;
thus, the amount of offset can depend on the data in the file.
  
* A_TEXT_SEEK(HDR)

If defined, this macro specifies the number of bytes to seek into the
a.out file before starting to write the text segment.a

* EXEC_MAGIC

For machines using COFF, this macro, if defined, is a value stored
into the magic number field of the output file.

* ADJUST_EXEC_HEADER

This macro can be used to generate statements to adjust or
initialize nonstandard fields in the file header

* ADDR_CORRECT(ADDR)

Macro to correct an int which is the bit pattern of a pointer to a byte
into an int which is the number of a byte.

This macro has a default definition which is usually right.
This default definition is a no-op on most machines (where a
pointer looks like an int) but not on all machines.

154 155
*/

Jim Blandy's avatar
Jim Blandy committed
156 157 158
#define XCOFF
#define COFF
#define NO_REMAP
Jim Blandy's avatar
Jim Blandy committed
159

Jim Blandy's avatar
Jim Blandy committed
160 161 162
#ifndef emacs
#define PERROR(arg) perror (arg); return -1
#else
163
#include <config.h>
Jim Blandy's avatar
Jim Blandy committed
164 165
#define PERROR(file) report_error (file, new)
#endif
Jim Blandy's avatar
Jim Blandy committed
166

Jim Blandy's avatar
Jim Blandy committed
167
#ifndef CANNOT_DUMP  /* all rest of file!  */
Jim Blandy's avatar
Jim Blandy committed
168

Jim Blandy's avatar
Jim Blandy committed
169
#ifndef CANNOT_UNEXEC /* most of rest of file */
Jim Blandy's avatar
Jim Blandy committed
170

Jim Blandy's avatar
Jim Blandy committed
171 172 173 174 175
#include <a.out.h>
/* Define getpagesize () if the system does not.
   Note that this may depend on symbols defined in a.out.h
 */
#include "getpagesize.h"
Jim Blandy's avatar
Jim Blandy committed
176

Jim Blandy's avatar
Jim Blandy committed
177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250
#ifndef makedev			/* Try to detect types.h already loaded */
#include <sys/types.h>
#endif
#include <stdio.h>
#include <sys/stat.h>
#include <errno.h>

extern char *start_of_text ();		/* Start of text */
extern char *start_of_data ();		/* Start of initialized data */

extern int _data;
extern int _edata;
extern int _text;
extern int _etext;
extern int _end;
#ifdef COFF
#ifndef USG
#ifndef STRIDE
#ifndef UMAX
#ifndef sun386
/* I have a suspicion that these are turned off on all systems
   and can be deleted.  Try it in version 19.  */
#include <filehdr.h>
#include <aouthdr.h>
#include <scnhdr.h>
#include <syms.h>
#endif /* not sun386 */
#endif /* not UMAX */
#endif /* Not STRIDE */
#endif /* not USG */
static long block_copy_start;		/* Old executable start point */
static struct filehdr f_hdr;		/* File header */
static struct aouthdr f_ohdr;		/* Optional file header (a.out) */
long bias;			/* Bias to add for growth */
long lnnoptr;			/* Pointer to line-number info within file */
#define SYMS_START block_copy_start

static long text_scnptr;
static long data_scnptr;
#ifdef XCOFF
static long load_scnptr;
static long orig_load_scnptr;
static long orig_data_scnptr;
#endif
static long data_st;

#ifndef MAX_SECTIONS
#define MAX_SECTIONS	10
#endif

#endif /* COFF */

static int pagemask;

/* Correct an int which is the bit pattern of a pointer to a byte
   into an int which is the number of a byte.
   This is a no-op on ordinary machines, but not on all.  */

#ifndef ADDR_CORRECT   /* Let m-*.h files override this definition */
#define ADDR_CORRECT(x) ((char *)(x) - (char*)0)
#endif

#ifdef emacs

static
report_error (file, fd)
     char *file;
     int fd;
{
  if (fd)
    close (fd);
  error ("Failure operating on %s", file);
}
#endif /* emacs */
Jim Blandy's avatar
Jim Blandy committed
251

Jim Blandy's avatar
Jim Blandy committed
252 253 254
#define ERROR0(msg) report_error_1 (new, msg, 0, 0); return -1
#define ERROR1(msg,x) report_error_1 (new, msg, x, 0); return -1
#define ERROR2(msg,x,y) report_error_1 (new, msg, x, y); return -1
Jim Blandy's avatar
Jim Blandy committed
255

Jim Blandy's avatar
Jim Blandy committed
256 257 258 259 260
static
report_error_1 (fd, msg, a1, a2)
     int fd;
     char *msg;
     int a1, a2;
Jim Blandy's avatar
Jim Blandy committed
261
{
Jim Blandy's avatar
Jim Blandy committed
262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283
  close (fd);
#ifdef emacs
  error (msg, a1, a2);
#else
  fprintf (stderr, msg, a1, a2);
  fprintf (stderr, "\n");
#endif
}

static int make_hdr ();
static void mark_x ();
static int copy_text_and_data ();
static int copy_sym ();

/* ****************************************************************
 * unexec
 *
 * driving logic.
 */
unexec (new_name, a_name, data_start, bss_start, entry_address)
     char *new_name, *a_name;
     unsigned data_start, bss_start, entry_address;
Jim Blandy's avatar
Jim Blandy committed
284
{
Jim Blandy's avatar
Jim Blandy committed
285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304
  int new, a_out = -1;

  if (a_name && (a_out = open (a_name, 0)) < 0)
    {
      PERROR (a_name);
    }
  if ((new = creat (new_name, 0666)) < 0)
    {
      PERROR (new_name);
    }
  if (make_hdr (new,a_out,data_start,bss_start,entry_address,a_name,new_name) < 0
      || copy_text_and_data (new) < 0
      || copy_sym (new, a_out, a_name, new_name) < 0
#ifdef COFF
      || adjust_lnnoptrs (new, a_out, new_name) < 0
#endif
#ifdef XCOFF
      || unrelocate_symbols (new, a_out, a_name, new_name) < 0
#endif
      )
Jim Blandy's avatar
Jim Blandy committed
305
    {
Jim Blandy's avatar
Jim Blandy committed
306 307 308
      close (new);
      /* unlink (new_name);	    	/* Failed, unlink new a.out */
      return -1;	
Jim Blandy's avatar
Jim Blandy committed
309 310
    }

Jim Blandy's avatar
Jim Blandy committed
311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362
  close (new);
  if (a_out >= 0)
    close (a_out);
  mark_x (new_name);
  return 0;
}

/* ****************************************************************
 * make_hdr
 *
 * Make the header in the new a.out from the header in core.
 * Modify the text and data sizes.
 */
static int
make_hdr (new, a_out, data_start, bss_start, entry_address, a_name, new_name)
     int new, a_out;
     unsigned data_start, bss_start, entry_address;
     char *a_name;
     char *new_name;
{
  register int scns;
  unsigned int bss_end;

  struct scnhdr section[MAX_SECTIONS];
  struct scnhdr * f_thdr;		/* Text section header */
  struct scnhdr * f_dhdr;		/* Data section header */
  struct scnhdr * f_bhdr;		/* Bss section header */
  struct scnhdr * f_lhdr;		/* Loader section header */
  struct scnhdr * f_tchdr;		/* Typechk section header */
  struct scnhdr * f_dbhdr;		/* Debug section header */
  struct scnhdr * f_xhdr;		/* Except section header */

  load_scnptr = orig_load_scnptr = lnnoptr = 0;
  pagemask = getpagesize () - 1;

  /* Adjust text/data boundary. */
#ifdef NO_REMAP
  data_start = (long) start_of_data ();
#endif /*  NO_REMAP */
  data_start = ADDR_CORRECT (data_start);

#ifdef SEGMENT_MASK
  data_start = data_start & ~SEGMENT_MASK; /* (Down) to segment boundary. */
#else
  data_start = data_start & ~pagemask; /* (Down) to page boundary. */
#endif


  bss_end = ADDR_CORRECT (sbrk (0)) + pagemask;
  bss_end &= ~ pagemask;
  /* Adjust data/bss boundary. */
  if (bss_start != 0)
Jim Blandy's avatar
Jim Blandy committed
363
    {
Jim Blandy's avatar
Jim Blandy committed
364 365 366 367
      bss_start = (ADDR_CORRECT (bss_start) + pagemask);
      /* (Up) to page bdry. */
      bss_start &= ~ pagemask;
      if (bss_start > bss_end)
Jim Blandy's avatar
Jim Blandy committed
368
	{
Jim Blandy's avatar
Jim Blandy committed
369 370
	  ERROR1 ("unexec: Specified bss_start (%u) is past end of program",
		  bss_start);
Jim Blandy's avatar
Jim Blandy committed
371 372
	}
    }
Jim Blandy's avatar
Jim Blandy committed
373 374
  else
    bss_start = bss_end;
Jim Blandy's avatar
Jim Blandy committed
375

Jim Blandy's avatar
Jim Blandy committed
376 377 378 379 380
  if (data_start > bss_start)	/* Can't have negative data size. */
    {
      ERROR2 ("unexec: data_start (%u) can't be greater than bss_start (%u)",
	      data_start, bss_start);
    }
Jim Blandy's avatar
Jim Blandy committed
381

Jim Blandy's avatar
Jim Blandy committed
382 383 384 385 386 387
#ifdef COFF
  /* Salvage as much info from the existing file as possible */
  block_copy_start = 0;
  f_thdr = NULL; f_dhdr = NULL; f_bhdr = NULL;
  f_lhdr = NULL; f_tchdr = NULL; f_dbhdr = NULL; f_xhdr = NULL;
  if (a_out >= 0)
Jim Blandy's avatar
Jim Blandy committed
388
    {
Jim Blandy's avatar
Jim Blandy committed
389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451
      if (read (a_out, &f_hdr, sizeof (f_hdr)) != sizeof (f_hdr))
	{
	  PERROR (a_name);
	}
      block_copy_start += sizeof (f_hdr);
      if (f_hdr.f_opthdr > 0)
	{
	  if (read (a_out, &f_ohdr, sizeof (f_ohdr)) != sizeof (f_ohdr))
	    {
	      PERROR (a_name);
	    }
	  block_copy_start += sizeof (f_ohdr);
	}
      if (f_hdr.f_nscns > MAX_SECTIONS)
	{
	  ERROR0 ("unexec: too many section headers -- increase MAX_SECTIONS");
	}
      /* Loop through section headers */
      for (scns = 0; scns < f_hdr.f_nscns; scns++) {
	struct scnhdr *s = &section[scns];
	if (read (a_out, s, sizeof (*s)) != sizeof (*s))
	  {
	    PERROR (a_name);
	  }
	if (s->s_scnptr > 0L)
	  {
            if (block_copy_start < s->s_scnptr + s->s_size)
	      block_copy_start = s->s_scnptr + s->s_size;
	  }

#define CHECK_SCNHDR(ptr, name, flags) \
  if (strcmp(s->s_name, name) == 0) { \
    if (s->s_flags != flags) { \
      fprintf(stderr, "unexec: %x flags where %x expected in %s section.\n", \
	      s->s_flags, flags, name); \
    } \
    if (ptr) { \
      fprintf(stderr, "unexec: duplicate section header for section %s.\n", \
	      name); \
    } \
    ptr = s; \
  }
	CHECK_SCNHDR(f_thdr, _TEXT, STYP_TEXT);
	CHECK_SCNHDR(f_dhdr, _DATA, STYP_DATA);
	CHECK_SCNHDR(f_bhdr, _BSS, STYP_BSS);
	CHECK_SCNHDR(f_lhdr, _LOADER, STYP_LOADER);
	CHECK_SCNHDR(f_dbhdr, _DEBUG,  STYP_DEBUG);
	CHECK_SCNHDR(f_tchdr, _TYPCHK,  STYP_TYPCHK);
	CHECK_SCNHDR(f_xhdr, _EXCEPT,  STYP_EXCEPT);
      }

      if (f_thdr == 0)
	{
	  ERROR1 ("unexec: couldn't find \"%s\" section", _TEXT);
	}
      if (f_dhdr == 0)
	{
	  ERROR1 ("unexec: couldn't find \"%s\" section", _DATA);
	}
      if (f_bhdr == 0)
	{
	  ERROR1 ("unexec: couldn't find \"%s\" section", _BSS);
	}
Jim Blandy's avatar
Jim Blandy committed
452
    }
Jim Blandy's avatar
Jim Blandy committed
453
  else
Jim Blandy's avatar
Jim Blandy committed
454
    {
Jim Blandy's avatar
Jim Blandy committed
455
      ERROR0 ("can't build a COFF file from scratch yet");
Jim Blandy's avatar
Jim Blandy committed
456
    }
Jim Blandy's avatar
Jim Blandy committed
457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490
  orig_data_scnptr = f_dhdr->s_scnptr;
  orig_load_scnptr = f_lhdr ? f_lhdr->s_scnptr : 0;

  /* Now we alter the contents of all the f_*hdr variables
     to correspond to what we want to dump.  */
  f_hdr.f_flags |= (F_RELFLG | F_EXEC);		/* Why? */
#ifdef EXEC_MAGIC
  f_ohdr.magic = EXEC_MAGIC;
#endif
#ifndef NO_REMAP
  f_ohdr.tsize = data_start - f_ohdr.text_start;
  f_ohdr.text_start = (long) start_of_text ();
#endif
  f_ohdr.dsize = bss_start - ((unsigned) &_data);
  f_ohdr.bsize = bss_end - bss_start;

  f_dhdr->s_size = f_ohdr.dsize;
  f_bhdr->s_size = f_ohdr.bsize;
  f_bhdr->s_paddr = f_ohdr.dsize;
  f_bhdr->s_vaddr = f_ohdr.dsize;

  /* fix scnptr's */
  {
    long ptr;

    for (scns = 0; scns < f_hdr.f_nscns; scns++) {
      struct scnhdr *s = &section[scns];
      if (scns == 0)
	ptr = s->s_scnptr;

      if (s->s_scnptr != 0)
	{
	  s->s_scnptr = ptr;
	}
Jim Blandy's avatar
Jim Blandy committed
491

Jim Blandy's avatar
Jim Blandy committed
492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527
      if ((s->s_flags & 0xffff) == STYP_PAD)
	{
	  /*
	   * the text_start should probably be o_algntext but that doesn't
	   * seem to change
	   */
	  if (f_ohdr.text_start != 0) /* && scns != 0 */
	    {
	      s->s_size = 512 - (s->s_scnptr % 512);
	      if (s->s_size == 512)
		s->s_size = 0;
	    }
	}

      ptr = ptr + s->s_size;
    }

    bias = ptr - block_copy_start;
  }

  /* fix other pointers */
  for (scns = 0; scns < f_hdr.f_nscns; scns++) {
    struct scnhdr *s = &section[scns];

    if (s->s_relptr != 0)
      {
	s->s_relptr += bias;
      }
    if (s->s_lnnoptr != 0)
      {
	if (lnnoptr == 0) lnnoptr = s->s_lnnoptr;
	s->s_lnnoptr += bias;
      }
  }

  if (f_hdr.f_symptr > 0L)
Jim Blandy's avatar
Jim Blandy committed
528
    {
Jim Blandy's avatar
Jim Blandy committed
529
      f_hdr.f_symptr += bias;
Jim Blandy's avatar
Jim Blandy committed
530 531
    }

Jim Blandy's avatar
Jim Blandy committed
532 533 534 535 536
  data_st = data_start;
  text_scnptr = f_thdr->s_scnptr;
  data_scnptr = f_dhdr->s_scnptr;
  load_scnptr = f_lhdr ? f_lhdr->s_scnptr : 0;
  block_copy_start = orig_load_scnptr;
Jim Blandy's avatar
Jim Blandy committed
537

Jim Blandy's avatar
Jim Blandy committed
538 539 540
#ifdef ADJUST_EXEC_HEADER
  ADJUST_EXEC_HEADER
#endif /* ADJUST_EXEC_HEADER */
Jim Blandy's avatar
Jim Blandy committed
541

Jim Blandy's avatar
Jim Blandy committed
542 543 544 545
  if (write (new, &f_hdr, sizeof (f_hdr)) != sizeof (f_hdr))
    {
      PERROR (new_name);
    }
Jim Blandy's avatar
Jim Blandy committed
546

Jim Blandy's avatar
Jim Blandy committed
547 548 549
  if (f_hdr.f_opthdr > 0)
    {
      if (write (new, &f_ohdr, sizeof (f_ohdr)) != sizeof (f_ohdr))
Jim Blandy's avatar
Jim Blandy committed
550
	{
Jim Blandy's avatar
Jim Blandy committed
551 552 553
	  PERROR (new_name);
	}
    }
Jim Blandy's avatar
Jim Blandy committed
554

Jim Blandy's avatar
Jim Blandy committed
555 556 557 558 559 560 561
  for (scns = 0; scns < f_hdr.f_nscns; scns++) {
    struct scnhdr *s = &section[scns];
    if (write (new, s, sizeof (*s)) != sizeof (*s))
      {
	PERROR (new_name);
      }
  }
Jim Blandy's avatar
Jim Blandy committed
562

Jim Blandy's avatar
Jim Blandy committed
563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600
  return (0);

#endif /* COFF */
}

/* ****************************************************************
 
 *
 * Copy the text and data segments from memory to the new a.out
 */
static int
copy_text_and_data (new)
     int new;
{
  register char *end;
  register char *ptr;

  lseek (new, (long) text_scnptr, 0);
  ptr = start_of_text () + text_scnptr;
  end = ptr + f_ohdr.tsize;
  write_segment (new, ptr, end);

  lseek (new, (long) data_scnptr, 0);
  ptr = (char *) &_data;
  end = ptr + f_ohdr.dsize;
  write_segment (new, ptr, end);

  return 0;
}

write_segment (new, ptr, end)
     int new;
     register char *ptr, *end;
{
  register int i, nwrite, ret;
  char buf[80];
  extern int errno;
  char zeros[128];
Jim Blandy's avatar
Jim Blandy committed
601

Jim Blandy's avatar
Jim Blandy committed
602 603 604 605 606 607 608 609 610 611 612 613 614 615
  bzero (zeros, sizeof zeros);

  for (i = 0; ptr < end;)
    {
      /* distance to next multiple of 128.  */
      nwrite = (((int) ptr + 128) & -128) - (int) ptr;
      /* But not beyond specified end.  */
      if (nwrite > end - ptr) nwrite = end - ptr;
      ret = write (new, ptr, nwrite);
      /* If write gets a page fault, it means we reached
	 a gap between the old text segment and the old data segment.
	 This gap has probably been remapped into part of the text segment.
	 So write zeros for it.  */
      if (ret == -1 && errno == EFAULT)
Jim Blandy's avatar
Jim Blandy committed
616
	{
Jim Blandy's avatar
Jim Blandy committed
617
	write (new, zeros, nwrite);
Jim Blandy's avatar
Jim Blandy committed
618
	}
Jim Blandy's avatar
Jim Blandy committed
619
      else if (nwrite != ret)
Jim Blandy's avatar
Jim Blandy committed
620
	{
Jim Blandy's avatar
Jim Blandy committed
621 622 623 624
	  sprintf (buf,
		   "unexec write failure: addr 0x%x, fileno %d, size 0x%x, wrote 0x%x, errno %d",
		   ptr, new, nwrite, ret, errno);
	  PERROR (buf);
Jim Blandy's avatar
Jim Blandy committed
625
	}
Jim Blandy's avatar
Jim Blandy committed
626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642
      i += nwrite;
      ptr += nwrite;
    }
}

/* ****************************************************************
 * copy_sym
 *
 * Copy the relocation information and symbol table from the a.out to the new
 */
static int
copy_sym (new, a_out, a_name, new_name)
     int new, a_out;
     char *a_name, *new_name;
{
  char page[1024];
  int n;
Jim Blandy's avatar
Jim Blandy committed
643

Jim Blandy's avatar
Jim Blandy committed
644 645
  if (a_out < 0)
    return 0;
Jim Blandy's avatar
Jim Blandy committed
646

Jim Blandy's avatar
Jim Blandy committed
647 648
  if (SYMS_START == 0L)
    return 0;
Jim Blandy's avatar
Jim Blandy committed
649

Jim Blandy's avatar
Jim Blandy committed
650 651 652 653 654 655 656 657
  if (lnnoptr && lnnoptr < SYMS_START)	/* if there is line number info */
    lseek (a_out, lnnoptr, 0);		/* start copying from there */
  else
    lseek (a_out, SYMS_START, 0);	/* Position a.out to symtab. */

  while ((n = read (a_out, page, sizeof page)) > 0)
    {
      if (write (new, page, n) != n)
Jim Blandy's avatar
Jim Blandy committed
658
	{
Jim Blandy's avatar
Jim Blandy committed
659
	  PERROR (new_name);
Jim Blandy's avatar
Jim Blandy committed
660 661
	}
    }
Jim Blandy's avatar
Jim Blandy committed
662 663 664 665 666 667 668 669 670 671
  if (n < 0)
    {
      PERROR (a_name);
    }
  return 0;
}

/* ****************************************************************
 * mark_x
 *
672
 * After successfully building the new a.out, mark it executable
Jim Blandy's avatar
Jim Blandy committed
673 674 675 676 677 678 679 680
 */
static void
mark_x (name)
     char *name;
{
  struct stat sbuf;
  int um;
  int new = 0;  /* for PERROR */
Jim Blandy's avatar
Jim Blandy committed
681

Jim Blandy's avatar
Jim Blandy committed
682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756
  um = umask (777);
  umask (um);
  if (stat (name, &sbuf) == -1)
    {
      PERROR (name);
    }
  sbuf.st_mode |= 0111 & ~um;
  if (chmod (name, sbuf.st_mode) == -1)
    PERROR (name);
}

/*
 *	If the COFF file contains a symbol table and a line number section,
 *	then any auxiliary entries that have values for x_lnnoptr must
 *	be adjusted by the amount that the line number section has moved
 *	in the file (bias computed in make_hdr).  The #@$%&* designers of
 *	the auxiliary entry structures used the absolute file offsets for
 *	the line number entry rather than an offset from the start of the
 *	line number section!
 *
 *	When I figure out how to scan through the symbol table and pick out
 *	the auxiliary entries that need adjustment, this routine will
 *	be fixed.  As it is now, all such entries are wrong and sdb
 *	will complain.   Fred Fish, UniSoft Systems Inc.
 */

#ifdef COFF

/* This function is probably very slow.  Instead of reopening the new
   file for input and output it should copy from the old to the new
   using the two descriptors already open (WRITEDESC and READDESC).
   Instead of reading one small structure at a time it should use
   a reasonable size buffer.  But I don't have time to work on such
   things, so I am installing it as submitted to me.  -- RMS.  */

adjust_lnnoptrs (writedesc, readdesc, new_name)
     int writedesc;
     int readdesc;
     char *new_name;
{
  register int nsyms;
  register int new;
#ifdef amdahl_uts
  SYMENT symentry;
  AUXENT auxentry;
#else
  struct syment symentry;
  union auxent auxentry;
#endif

  if (!lnnoptr || !f_hdr.f_symptr)
    return 0;

  if ((new = open (new_name, 2)) < 0)
    {
      PERROR (new_name);
      return -1;
    }

  lseek (new, f_hdr.f_symptr, 0);
  for (nsyms = 0; nsyms < f_hdr.f_nsyms; nsyms++)
    {
      read (new, &symentry, SYMESZ);
      if (symentry.n_numaux)
	{
	  read (new, &auxentry, AUXESZ);
	  nsyms++;
	  if (ISFCN (symentry.n_type)) {
	    auxentry.x_sym.x_fcnary.x_fcn.x_lnnoptr += bias;
	    lseek (new, -AUXESZ, 1);
	    write (new, &auxentry, AUXESZ);
	  }
	}
    }
  close (new);
Jim Blandy's avatar
Jim Blandy committed
757 758
}

Jim Blandy's avatar
Jim Blandy committed
759
#endif /* COFF */
Jim Blandy's avatar
Jim Blandy committed
760

Jim Blandy's avatar
Jim Blandy committed
761 762 763 764 765 766 767 768 769
#ifdef XCOFF

/* It is probably a false economy to optimise this routine (it used to
   read one LDREL and do do two lseeks per iteration) but the wrath of
   RMS (see above :-) would be too much to bear */

unrelocate_symbols (new, a_out, a_name, new_name)
     int new, a_out;
     char *a_name, *new_name;
Jim Blandy's avatar
Jim Blandy committed
770
{
Jim Blandy's avatar
Jim Blandy committed
771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865
  register int i;
  register int l;
  register LDREL *ldrel;
  LDHDR ldhdr;
  LDREL ldrel_buf [20];
  ulong t_start = (ulong) &_text;
  ulong d_start = (ulong) &_data;
  int * p;
  int dirty;

  if (load_scnptr == 0)
    return 0;

  lseek (a_out, orig_load_scnptr, 0);
  if (read (a_out, &ldhdr, sizeof (ldhdr)) != sizeof (ldhdr))
    {
      PERROR (new_name);
    }

#define SYMNDX_TEXT	0
#define SYMNDX_DATA	1
#define SYMNDX_BSS	2
  l = 0;
  for (i = 0; i < ldhdr.l_nreloc; i++, l--, ldrel++)
    {
      if (l == 0) {
	lseek (a_out,
	       orig_load_scnptr + LDHDRSZ + LDSYMSZ*ldhdr.l_nsyms + LDRELSZ*i,
	       0);

	l = ldhdr.l_nreloc - i;
	if (l > sizeof (ldrel_buf) / LDRELSZ)
	  l = sizeof (ldrel_buf) / LDRELSZ;

	if (read (a_out, ldrel_buf, l * LDRELSZ) != l * LDRELSZ)
	  {
	    PERROR (a_name);
	  }
	ldrel = ldrel_buf;
      }
      dirty = 0;

      /* this code may not be necessary */
      /* I originally had == in the "assignment" and it still unrelocated */

      /* move the BSS loader symbols to the DATA segment */
      if (ldrel->l_rsecnm == f_ohdr.o_snbss)
	ldrel->l_rsecnm = f_ohdr.o_sndata, dirty++;

      if (ldrel->l_symndx == SYMNDX_BSS)
	ldrel->l_symndx = SYMNDX_DATA, dirty++;

      if (dirty)
	{
	  lseek (new,
		 load_scnptr + LDHDRSZ + LDSYMSZ*ldhdr.l_nsyms + LDRELSZ*i,
		 0);

	  if (write (new, ldrel, LDRELSZ) != LDRELSZ)
	    {
	      PERROR (new_name);
	    }
	}

      if (ldrel->l_rsecnm == f_ohdr.o_sndata)
	{
	  int orig_int;

	  lseek (a_out, orig_data_scnptr + ldrel->l_vaddr, 0);

	  if (read (a_out, (void *) &orig_int, sizeof (orig_int)) != sizeof (orig_int))
	    {
	      PERROR (a_name);
	    }

	  switch (ldrel->l_symndx) {
	  case SYMNDX_TEXT:
	    p = (int *) (d_start + ldrel->l_vaddr);
	    orig_int = * p - (t_start - f_ohdr.text_start);
	    break;

	  case SYMNDX_DATA:
	  case SYMNDX_BSS:
	    p = (int *) (d_start + ldrel->l_vaddr);
	    orig_int = * p - (d_start - f_ohdr.data_start);
	    break;
	  }

	  lseek (new, data_scnptr + ldrel->l_vaddr, 0);
	  if (write (new, (void *) &orig_int, sizeof (orig_int)) != sizeof (orig_int))
	    {
	      PERROR (new_name);
	    }
	}
    }
Jim Blandy's avatar
Jim Blandy committed
866
}
Jim Blandy's avatar
Jim Blandy committed
867 868 869 870 871
#endif /* XCOFF */

#endif /* not CANNOT_UNEXEC */

#endif /* not CANNOT_DUMP */