Source

xemacs-beta / src / unexelfsgi.c

  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
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
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
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
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
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
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
452
453
454
455
456
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
491
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
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
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
/* Copyright (C) 1985, 1986, 1987, 1988, 1990, 1992, 1999, 2000
   Free Software Foundation, Inc.

   This file is part of XEmacs.

   XEmacs 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 2, or (at your option)
   any later version.

   GNU Emacs 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 GNU Emacs; see the file COPYING.  If not, write to the
   Free Software Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, 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:
 * void
 * unexec (char *new_name,
 *	   char *old_name,
 *	   uintptr_t data_start,
 *	   uintptr_t bss_start,
 *	   uintptr_t entry_address)
 *
 * The basic idea is that we start with an ELF file which contains
 * .bss (uninitialized global data) section which is normally not in
 * the file. As we load lisp the variables, which were first set to 0,
 * will change their values. We want to save those changed values into
 * another ELF file, which will become a new xemacs image. To do this,
 * we need to change several structures in the ELF file.
 *
 *   First of all, we need to change the programm header which tells
 *   the linker how to load stuff into memory so that data will come
 *   from the file and not from the /dev/zero. To do this, we find the
 *   segment, which is marked as loadable (type PT_LOAD) and which
 *   covers the old .bss section. We will next change the filesz and
 *   memsz for that segment to extend over the new data section.
 *
 *   Next we have to make sure that section header for the stuff which
 *   used to be uninitialized is changed to be initialized and to come
 *   from the file. To do this, we change the size and the type of the old
 *   .bss section (and all other section of the type SHT_NOBITS) to cover the
 *   new section and to be of type SHT_PROCBITS.
 *
 *   We also insert a new SHT_NOBITS section to keep some tools, which expect
 *   .bss happy.
 *
 *   Finally we need to patch up some references to the section
 *   indexes since we change the order and undo the relocation info to
 *   be the same as it was "before" because we actually used the data
 *   from the memory which were changed by the run-time linker.
 */

#ifndef emacs
#define fatal(a, b, c) fprintf (stderr, a, b, c), exit (1)
#include <string.h>
#else
#include <config.h>
extern void fatal (const char *, ...);
#endif

#include <sys/types.h>
#include <stdio.h>
#include <sys/stat.h>
#include <memory.h>
#include <errno.h>
#include <unistd.h>
#include <fcntl.h>
#include <elf.h>
#include <sys/mman.h>
#if defined (__sony_news) && defined (_SYSTYPE_SYSV)
#include <sys/elf_mips.h>
#include <sym.h>
#endif /* __sony_news && _SYSTYPE_SYSV */
#if __sgi
#include <syms.h> /* for HDRR declaration */
#endif /* __sgi */

#if __GNU_LIBRARY__ - 0 >= 6
# include <link.h>	/* get ElfW etc */
#endif

#ifndef ElfW
# ifdef __STDC__
#  define ElfBitsW(bits, type) Elf##bits##_##type
# else
#  define ElfBitsW(bits, type) Elf/**/bits/**/_/**/type
# endif
# ifdef _LP64
#  define ELFSIZE 64
# else
#  define ELFSIZE 32
# endif
  /* This macro expands `bits' before invoking ElfBitsW.  */
# define ElfExpandBitsW(bits, type) ElfBitsW (bits, type)
# define ElfW(type) ElfExpandBitsW (ELFSIZE, type)
#endif

#ifndef ELF_BSS_SECTION_NAME
#define ELF_BSS_SECTION_NAME ".bss"
#endif

/* Get the address of a particular section or program header entry,
 * accounting for the size of the entries. */

#define OLD_SECTION_H(n) \
     (*(ElfW(Shdr) *) ((byte *) old_section_h + old_file_h->e_shentsize * (n)))
#define NEW_SECTION_H(n) \
     (*(ElfW(Shdr) *) ((byte *) new_section_h + new_file_h->e_shentsize * (n)))
#define OLD_PROGRAM_H(n) \
     (*(ElfW(Phdr) *) ((byte *) old_program_h + old_file_h->e_phentsize * (n)))
#define NEW_PROGRAM_H(n) \
     (*(ElfW(Phdr) *) ((byte *) new_program_h + new_file_h->e_phentsize * (n)))

#define PATCH_INDEX(n) \
  do { \
	 if ((int) (n) >= growme_index) \
	   (n)++; } while (0)

typedef unsigned char byte;

/* Round X up to a multiple of Y.  */

static ElfW(Addr)
round_up (ElfW(Addr) x, ElfW(Addr) y)
{
  int rem = x % y;
  if (rem == 0)
    return x;
  return x - rem + y;
}

/* Return the index of the section named NAME.
   SECTION_NAMES, FILE_NAME and FILE_H give information
   about the file we are looking in.

   If we don't find the section NAME, that is a fatal error
   if NOERROR is 0; we return -1 if NOERROR is nonzero.  */

static int
find_section (char *name,
	      const char *section_names,
	      char *file_name,
	      ElfW(Ehdr) *old_file_h,
	      ElfW(Shdr) *old_section_h,
	      int noerror)
{
  int idx;

  for (idx = 1; idx < old_file_h->e_shnum; idx++)
    {
#ifdef DEBUG
      fprintf (stderr, "Looking for %s - found %s\n", name,
	       section_names + OLD_SECTION_H (idx).sh_name);
#endif
      if (!strcmp (section_names + OLD_SECTION_H (idx).sh_name,
		   name))
	  return idx;
    }

  /* If we're here, we found nothing or return did not work */
  if ( ! noerror)
      fatal ("Can't find %s in %s.\n", name, file_name);

  return -1;
}

/* ****************************************************************
 * unexec
 *
 * driving logic.
 *
 * In ELF, this works by replacing the old .bss section with a new
 * .data section, and inserting an empty .bss immediately afterwards.
 *
 */
void
unexec (char *new_name,
	char *old_name,
	uintptr_t data_start,
	uintptr_t bss_start,
	uintptr_t entry_address)
{
  int old_file;

  struct stat stat_buf;
  caddr_t old_base, new_base;

  ElfW(Ehdr) *old_file_h, * new_file_h;
  ElfW(Phdr) *old_program_h, * new_program_h;
  ElfW(Shdr) *old_section_h, * new_section_h;
  ElfW(Shdr) * growme = NULL, * grown = NULL;
  ElfW(Addr) old_bss_addr = 0,  new_data2_addr = 0;

  int growme_index = -1;
  int n, nn;
  const char *old_section_names;
  int old_mdebug_index, old_data_index;
  int new_bss_addr, new_data2_size, new_data2_offset, new_file, new_file_size;

  /* Open the old file */
  if ( (old_file = open (old_name, O_RDONLY)) < 0 )
      fatal ("Can't open %s for reading: errno %d\n", old_name, errno);

  if (fstat (old_file, &stat_buf) == -1)
      fatal ("Can't fstat (%s): errno %d\n", old_name, errno);

  /* map old file into the address space. */
  old_base = (caddr_t) mmap ((caddr_t) 0, stat_buf.st_size,
			     PROT_READ, MAP_SHARED, old_file, 0);
  if (old_base == (caddr_t) MAP_FAILED)
    fatal ("Can't mmap (%s): errno %d\n", old_name, errno);

  old_file_h    = (ElfW(Ehdr) *) old_base;
  old_program_h = (ElfW(Phdr) *) ((byte *) old_base + old_file_h->e_phoff);
  old_section_h = (ElfW(Shdr) *) ((byte *) old_base + old_file_h->e_shoff);
  old_section_names = (const char *) old_base
      + OLD_SECTION_H (old_file_h->e_shstrndx).sh_offset;

  /* Find a section which we will grow by looking for the SHT_NOBITS
   * section with ALLOCATE flag and with the biggest address. */
  for (n = 1; n < old_file_h->e_shnum; n++) {
      ElfW(Shdr) * sh = & OLD_SECTION_H(n);

      if ((sh->sh_type == SHT_NOBITS) && (sh->sh_flags & SHF_ALLOC)) {
	  if ( old_bss_addr < sh->sh_addr ) {
	      growme = sh;
	      growme_index = n;
	      new_data2_addr = old_bss_addr =  sh->sh_addr;
	  }
      }
  }

  if (growme == NULL )
      fatal ("Can't find a section to grow\n", 0, 0);

  old_data_index = find_section (".data", old_section_names,
				 old_name, old_file_h, old_section_h, 0);

  new_bss_addr = (ElfW(Addr)) sbrk (0);
  new_data2_size = new_bss_addr - old_bss_addr;
  new_data2_offset  = OLD_SECTION_H (old_data_index).sh_offset +
      (new_data2_addr - OLD_SECTION_H (old_data_index).sh_addr);

  if ( new_bss_addr < old_bss_addr + growme->sh_size )
      fatal (".bss shrank when undumping???\n", 0, 0);

  /* Set the output file to the right size and mmap it. */
  if ( (new_file = open (new_name, O_RDWR | O_CREAT, 0666)) < 0 )
      fatal ("Can't create (%s): errno %d\n", new_name, errno);

  new_file_size = stat_buf.st_size +  old_file_h->e_shentsize + new_data2_size;

  if (ftruncate (new_file, new_file_size))
      fatal ("Can't ftruncate (%s): errno %d\n", new_name, errno);

  new_base = (caddr_t) mmap ((caddr_t) 0, new_file_size,
			     PROT_READ | PROT_WRITE,
#ifdef UNEXEC_USE_MAP_PRIVATE
			     MAP_PRIVATE,
#else
			     MAP_SHARED,
#endif
			     new_file, 0);

  if (new_base == (caddr_t) -1)
      fatal ("Can't mmap (%s): errno %d\n", new_name, errno);

  new_file_h = (ElfW(Ehdr) *) new_base;
  new_program_h = (ElfW(Phdr) *) ((byte *) new_base + old_file_h->e_phoff);
  new_section_h = (ElfW(Shdr) *) ((byte *) new_base + old_file_h->e_shoff +
				  new_data2_size);

  /* Make our new file, program and section headers as copies of the
   * originals.  */
  memcpy (new_file_h, old_file_h, old_file_h->e_ehsize);
  memcpy (new_program_h, old_program_h,
	  old_file_h->e_phnum * old_file_h->e_phentsize);

  /* Modify the e_shstrndx if necessary. */
  PATCH_INDEX (new_file_h->e_shstrndx);

  /* Fix up file header.  We'll add one section.  Section header is
   * further away now.  */
  new_file_h->e_shoff += new_data2_size;
  new_file_h->e_shnum += 1;

  /* Fix up a new program header by extending the writable data
   * segment so that the bss area is covered too. Find that segment by
   * looking for one that starts before and ends after the .bss and is
   * PT_LOADable. */
  for (n = new_file_h->e_phnum - 1; n >= 0; n--) {
      ElfW(Phdr) * ph = & NEW_PROGRAM_H(n);
#ifdef DEBUG
      printf ("%d @ %0x + %0x against %0x + %0x",
	      n, ph->p_vaddr, ph->p_memsz,growme->sh_addr, growme->sh_size);
#endif
      if ((ph->p_type == PT_LOAD) &&
	  (ph->p_vaddr <= growme->sh_addr) &&
	  ((ph->p_vaddr+ph->p_memsz) >= (growme->sh_addr + growme->sh_size))) {
	  /* Make sure that the size includes any padding before the
	   * old .bss section.  */
	  ph->p_memsz = ph->p_filesz = new_bss_addr - ph->p_vaddr;
#ifdef DEBUG
	  puts (" That's the one!");
#endif
	  break;
      }
#ifdef DEBUG
      putchar ('\n');
#endif
  }

  if (n < 0)
      fatal ("Couldn't find segment which covers %s",
	     old_section_names + growme->sh_name);

  /* Walk through all section headers, insert the new data2 section
   * right before the new bss section. */
  for (n = 1, nn = 1; n < (int) old_file_h->e_shnum;  n++, nn++) {
      ElfW(Shdr) * nsec = & NEW_SECTION_H(nn);
      ElfW(Shdr) * osec = & OLD_SECTION_H(n);

      /* If this is the section we want to grow, insert the new data
       * section before it. */
      if ( osec == growme ) {
	  /* Steal the data section header for this data2 section but
	   * use the * 'grow' section's alignment. This * will assure
	   * that the new section * always be placed in the same spot
	   * * as the old section by any other * application. */
	  ElfW(Shdr) * od = &OLD_SECTION_H(old_data_index);

	  memcpy (nsec, od, new_file_h->e_shentsize);

	  nsec->sh_addr = new_data2_addr;
	  nsec->sh_offset =  new_data2_offset;
	  nsec->sh_size = new_data2_size;
	  nsec->sh_addralign = osec->sh_addralign;

	  /* Copy over what we have in memory now. */
	  memcpy (nsec->sh_offset + new_base, (caddr_t) osec->sh_addr,
		  new_data2_size);
	  nn++;
	  grown = nsec++;
      }

      memcpy (nsec, osec, old_file_h->e_shentsize);

      if ( osec == growme ) {
	  /* The new bss section's size is zero, and its file offset
	   * and virtual address should be off by NEW_DATA2_SIZE.  */
	  nsec->sh_offset = grown->sh_offset + new_data2_size;
	  nsec->sh_addr = grown->sh_addr + new_data2_size;

	  /* Let the new bss section address alignment be the same as
	   * the section address alignment followed the old bss
	   * section, so this section will be placed in exactly the
	   * same place. */
	  nsec->sh_addralign = osec->sh_addralign;
	  nsec->sh_size = 0;
      } else {
	  /* Any section that was originally placed AFTER the bss
	   * section should now be off by NEW_DATA2_SIZE. */
	  if ( round_up (nsec->sh_offset, growme->sh_addralign) >=
	       new_data2_offset)
	      nsec->sh_offset += new_data2_size;
      }

      /* Any section that was originally placed after the section *
       * header table should now be off by the size of one section
       * header table entry.  */
      if (nsec->sh_offset > new_file_h->e_shoff)
	  nsec->sh_offset += new_file_h->e_shentsize;


      /* If any section hdr refers to the section after the new .data
       * section, make it refer to next one because we have inserted a
       * new section in between.  */
      PATCH_INDEX (nsec->sh_link);

      /* For symbol tables, info is a symbol table index, so don't
       * change it.  */
      if (nsec->sh_type != SHT_SYMTAB && nsec->sh_type != SHT_DYNSYM)
	  PATCH_INDEX (nsec->sh_info);

      /* Any section which used to be NOBITS will now becomes PROGBITS
       * if it's ALLOC-atable, unless, of cause, it's not the one we
       * decided to grow */
      if ( (osec->sh_type == SHT_NOBITS) && (osec->sh_flags & SHF_ALLOC) &&
	   (osec != growme ) ) {
	  nsec->sh_type = SHT_PROGBITS;
      }

      /* Now, start to copy the content of sections */
      if ( nsec->sh_type != SHT_NULL || nsec->sh_type != SHT_NOBITS ) {

	  /* Write out the sections. .data and .data1 (and data2,
	   * called ".data" in the strings table) get copied from the
	   * current process instead of the old file.  */
	  caddr_t src =  old_base + osec->sh_offset;
	  const char * secname = old_section_names + nsec->sh_name;
	  const char * names[] = {
	      ".data",".sdata", ".lit4", ".lit8", ".sdata1", ".data1",
	      ".sbss", NULL};
	  int i;

	  for ( i=0; names[i] != NULL; i++ ) {
	      if ( ! strcmp (secname, names[i]) ) {
		  src = (caddr_t) osec->sh_addr;
		  break;
	      }
	  }

	  memcpy (nsec->sh_offset + new_base, src, nsec->sh_size);
      }

      old_mdebug_index = find_section (".mdebug", old_section_names,
				       old_name, old_file_h, old_section_h, 1);

#if defined (__sony_news) && defined (_SYSTYPE_SYSV)
      if (nsec->sh_type == SHT_MIPS_DEBUG && old_mdebug_index != -1) {
	  int diff = nsec->sh_offset-OLD_SECTION_H(old_mdebug_index).sh_offset;
	  HDRR *phdr = (HDRR *)(nsec->sh_offset + new_base);

	  if (diff) {
	      phdr->cbLineOffset += diff;
	      phdr->cbDnOffset   += diff;
	      phdr->cbPdOffset   += diff;
	      phdr->cbSymOffset  += diff;
	      phdr->cbOptOffset  += diff;
	      phdr->cbAuxOffset  += diff;
	      phdr->cbSsOffset   += diff;
	      phdr->cbSsExtOffset += diff;
	      phdr->cbFdOffset   += diff;
	      phdr->cbRfdOffset  += diff;
	      phdr->cbExtOffset  += diff;
	  }
      }
#endif /* __sony_news && _SYSTYPE_SYSV */

#if __sgi
      /* Adjust the HDRR offsets in .mdebug and copy the line data if
       * it's in its usual 'hole' in the object.  Makes the new file
       * debuggable with dbx.  patches up two problems: the absolute
       * file offsets in the HDRR record of .mdebug (see
       * /usr/include/syms.h), and the ld bug that gets the line table
       * in a hole in the elf file rather than in the .mdebug section
       * proper.
       *
       * David Anderson. davea@sgi.com Jan 16,1994 */
#define MDEBUGADJUST(__ct,__fileaddr)		\
  if (n_phdrr->__ct > 0)			\
    {						\
      n_phdrr->__fileaddr += movement;		\
    }

      if (n == old_mdebug_index) {
	  HDRR * o_phdrr = (HDRR *)((byte *)old_base + osec->sh_offset);
	  HDRR * n_phdrr = (HDRR *)((byte *)new_base + nsec->sh_offset);
	  unsigned movement = new_data2_size;

	  MDEBUGADJUST (idnMax, cbDnOffset);
	  MDEBUGADJUST (ipdMax, cbPdOffset);
	  MDEBUGADJUST (isymMax, cbSymOffset);
	  MDEBUGADJUST (ioptMax, cbOptOffset);
	  MDEBUGADJUST (iauxMax, cbAuxOffset);
	  MDEBUGADJUST (issMax, cbSsOffset);
	  MDEBUGADJUST (issExtMax, cbSsExtOffset);
	  MDEBUGADJUST (ifdMax, cbFdOffset);
	  MDEBUGADJUST (crfd, cbRfdOffset);
	  MDEBUGADJUST (iextMax, cbExtOffset);

	  /* The Line Section, being possible off in a hole of the
	   * object, requires special handling.  */
	  if (n_phdrr->cbLine > 0) {
	      if (o_phdrr->cbLineOffset >
		  osec->sh_offset+ osec->sh_size){
		  /* line data is in a hole in elf. do special copy
		   * and adjust for this ld mistake.  */
		  n_phdrr->cbLineOffset += movement;

		  memcpy (n_phdrr->cbLineOffset + new_base,
			  o_phdrr->cbLineOffset + old_base, n_phdrr->cbLine);
	      } else {
		  /* somehow line data is in .mdebug as it is supposed
		   * to be.  */
		  MDEBUGADJUST (cbLine, cbLineOffset);
	      }
	  }
      }
#endif /* __sgi */
      /* If it is the symbol table, its st_shndx field needs to be
       * patched.  */
      if (nsec->sh_type == SHT_SYMTAB || nsec->sh_type == SHT_DYNSYM) {
	  unsigned int num = nsec->sh_size / nsec->sh_entsize;
	  ElfW(Sym) * sym = (ElfW(Sym) *)(nsec->sh_offset + new_base);
	  byte *symnames = ((byte *) new_base +
			    NEW_SECTION_H (nsec->sh_link).sh_offset);

	  for (; num--; sym++) {
	      const char * symnam = (char *) (symnames + sym->st_name);

	      /* Update the symbol values of _edata and _end. */
	      if (strcmp (symnam, "_end") == 0
		  || strcmp (symnam, "end") == 0
		  || strcmp (symnam, "_edata") == 0
		  || strcmp (symnam, "edata") == 0)
		  memcpy (&sym->st_value, &new_bss_addr,sizeof (new_bss_addr));


	      if ((sym->st_shndx == SHN_UNDEF) || (sym->st_shndx == SHN_ABS)
		  || (sym->st_shndx == SHN_COMMON)
		  || (sym->st_shndx >= SHN_LOPROC &&
		      sym->st_shndx <= SHN_HIPROC))
		  continue;

	      PATCH_INDEX (sym->st_shndx);
	  }
      }
  }

  /* This loop seeks out relocation sections for the data section, so
   * that it can undo relocations performed by the runtime linker.  */
  for (n = new_file_h->e_shnum - 1; n; n--) {
      ElfW(Shdr) section = NEW_SECTION_H (n);

      if ( section.sh_type == SHT_REL || section.sh_type == SHT_RELA ) {
	  /* This code handles two different size structs, but there
	   * should be no harm in that provided that r_offset is
	   * always the first member.  */
	  ElfW(Shdr) * info = & NEW_SECTION_H(section.sh_info);
	  const char * nm = old_section_names + info->sh_name;

	  if (!strcmp (nm, ".data") || !strcmp (nm, ".sdata")
	      || !strcmp (nm, ".lit4") || !strcmp (nm, ".lit8")
	      || !strcmp (nm, ".sdata1") || !strcmp (nm, ".data1")) {
	      ElfW(Addr) offset =  info->sh_addr - info->sh_offset;
	      caddr_t end, reloc = old_base + section.sh_offset;

	      for (end = reloc + section.sh_size; reloc < end;
		   reloc += section.sh_entsize) {
		  ElfW(Addr) addr = ((ElfW(Rel) *) reloc)->r_offset - offset;
#ifdef __alpha__
		  /* The Alpha ELF binutils currently have a bug that
		   * sometimes results in relocs that contain all
		   * zeroes.  Work around this for now...  */
		  if (((ElfW(Rel) *) reloc)->r_offset == 0)
		      continue;
#endif
		  memcpy (new_base + addr, old_base + addr,
			  sizeof(ElfW(Addr)));
	      }
	  }
      }
  }

#ifdef UNEXEC_USE_MAP_PRIVATE
  if (lseek (new_file, 0, SEEK_SET) == -1)
      fatal ("Can't rewind (%s): errno %d\n", new_name, errno);

  if (write (new_file, new_base, new_file_size) != new_file_size)
      fatal ("Can't write (%s): errno %d\n", new_name, errno);
#endif

  /* Close the files and make the new file executable.  */
  if (close (old_file))
      fatal ("Can't close (%s): errno %d\n", old_name, errno);

  if (close (new_file))
      fatal ("Can't close (%s): errno %d\n", new_name, errno);

  if (stat (new_name, &stat_buf) == -1)
      fatal ("Can't stat (%s): errno %d\n", new_name, errno);

  n = umask (777);
  umask (n);
  stat_buf.st_mode |= 0111 & ~n;
  if (chmod (new_name, stat_buf.st_mode) == -1)
      fatal ("Can't chmod (%s): errno %d\n", new_name, errno);
}