Mercurial > hg > xemacs-beta

comparison src/unexelfsgi.c @ 0:376386a54a3c r19-14

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Import from CVS: tag r19-14
author cvs
date Mon, 13 Aug 2007 08:45:50 +0200
parents
children ee648375d8d6
comparison
equal deleted inserted replaced
-1:000000000000 0:376386a54a3c
1 /* Copyright (C) 1985, 1986, 1987, 1988, 1990, 1992
2 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: FSF 19.31. */
22
23
24 /*
25 * unexec.c - Convert a running program into an a.out file.
26 *
27 * Author: Spencer W. Thomas
28 * Computer Science Dept.
29 * University of Utah
30 * Date: Tue Mar 2 1982
31 * Modified heavily since then.
32 *
33 * Synopsis:
34 * unexec (new_name, a_name, data_start, bss_start, entry_address)
35 * char *new_name, *a_name;
36 * unsigned data_start, bss_start, entry_address;
37 *
38 * Takes a snapshot of the program and makes an a.out format file in the
39 * file named by the string argument new_name.
40 * If a_name is non-NULL, the symbol table will be taken from the given file.
41 * On some machines, an existing a_name file is required.
42 *
43 * The boundaries within the a.out file may be adjusted with the data_start
44 * and bss_start arguments. Either or both may be given as 0 for defaults.
45 *
46 * Data_start gives the boundary between the text segment and the data
47 * segment of the program. The text segment can contain shared, read-only
48 * program code and literal data, while the data segment is always unshared
49 * and unprotected. Data_start gives the lowest unprotected address.
50 * The value you specify may be rounded down to a suitable boundary
51 * as required by the machine you are using.
52 *
53 * Specifying zero for data_start means the boundary between text and data
54 * should not be the same as when the program was loaded.
55 * If NO_REMAP is defined, the argument data_start is ignored and the
56 * segment boundaries are never changed.
57 *
58 * Bss_start indicates how much of the data segment is to be saved in the
59 * a.out file and restored when the program is executed. It gives the lowest
60 * unsaved address, and is rounded up to a page boundary. The default when 0
61 * is given assumes that the entire data segment is to be stored, including
62 * the previous data and bss as well as any additional storage allocated with
63 * break (2).
64 *
65 * The new file is set up to start at entry_address.
66 *
67 * If you make improvements I'd like to get them too.
68 * harpo!utah-cs!thomas, thomas@Utah-20
69 *
70 */
71
72 /* Even more heavily modified by james@bigtex.cactus.org of Dell Computer Co.
73 * ELF support added.
74 *
75 * Basic theory: the data space of the running process needs to be
76 * dumped to the output file. Normally we would just enlarge the size
77 * of .data, scooting everything down. But we can't do that in ELF,
78 * because there is often something between the .data space and the
79 * .bss space.
80 *
81 * In the temacs dump below, notice that the Global Offset Table
82 * (.got) and the Dynamic link data (.dynamic) come between .data1 and
83 * .bss. It does not work to overlap .data with these fields.
84 *
85 * The solution is to create a new .data segment. This segment is
86 * filled with data from the current process. Since the contents of
87 * various sections refer to sections by index, the new .data segment
88 * is made the last in the table to avoid changing any existing index.
89
90 * This is an example of how the section headers are changed. "Addr"
91 * is a process virtual address. "Offset" is a file offset.
92
93 raid:/nfs/raid/src/dist-18.56/src> dump -h temacs
94
95 temacs:
96
97 **** SECTION HEADER TABLE ****
98 [No] Type Flags Addr Offset Size Name
99 Link Info Adralgn Entsize
100
101 [1] 1 2 0x80480d4 0xd4 0x13 .interp
102 0 0 0x1 0
103
104 [2] 5 2 0x80480e8 0xe8 0x388 .hash
105 3 0 0x4 0x4
106
107 [3] 11 2 0x8048470 0x470 0x7f0 .dynsym
108 4 1 0x4 0x10
109
110 [4] 3 2 0x8048c60 0xc60 0x3ad .dynstr
111 0 0 0x1 0
112
113 [5] 9 2 0x8049010 0x1010 0x338 .rel.plt
114 3 7 0x4 0x8
115
116 [6] 1 6 0x8049348 0x1348 0x3 .init
117 0 0 0x4 0
118
119 [7] 1 6 0x804934c 0x134c 0x680 .plt
120 0 0 0x4 0x4
121
122 [8] 1 6 0x80499cc 0x19cc 0x3c56f .text
123 0 0 0x4 0
124
125 [9] 1 6 0x8085f3c 0x3df3c 0x3 .fini
126 0 0 0x4 0
127
128 [10] 1 2 0x8085f40 0x3df40 0x69c .rodata
129 0 0 0x4 0
130
131 [11] 1 2 0x80865dc 0x3e5dc 0xd51 .rodata1
132 0 0 0x4 0
133
134 [12] 1 3 0x8088330 0x3f330 0x20afc .data
135 0 0 0x4 0
136
137 [13] 1 3 0x80a8e2c 0x5fe2c 0x89d .data1
138 0 0 0x4 0
139
140 [14] 1 3 0x80a96cc 0x606cc 0x1a8 .got
141 0 0 0x4 0x4
142
143 [15] 6 3 0x80a9874 0x60874 0x80 .dynamic
144 4 0 0x4 0x8
145
146 [16] 8 3 0x80a98f4 0x608f4 0x449c .bss
147 0 0 0x4 0
148
149 [17] 2 0 0 0x608f4 0x9b90 .symtab
150 18 371 0x4 0x10
151
152 [18] 3 0 0 0x6a484 0x8526 .strtab
153 0 0 0x1 0
154
155 [19] 3 0 0 0x729aa 0x93 .shstrtab
156 0 0 0x1 0
157
158 [20] 1 0 0 0x72a3d 0x68b7 .comment
159 0 0 0x1 0
160
161 raid:/nfs/raid/src/dist-18.56/src> dump -h xemacs
162
163 xemacs:
164
165 **** SECTION HEADER TABLE ****
166 [No] Type Flags Addr Offset Size Name
167 Link Info Adralgn Entsize
168
169 [1] 1 2 0x80480d4 0xd4 0x13 .interp
170 0 0 0x1 0
171
172 [2] 5 2 0x80480e8 0xe8 0x388 .hash
173 3 0 0x4 0x4
174
175 [3] 11 2 0x8048470 0x470 0x7f0 .dynsym
176 4 1 0x4 0x10
177
178 [4] 3 2 0x8048c60 0xc60 0x3ad .dynstr
179 0 0 0x1 0
180
181 [5] 9 2 0x8049010 0x1010 0x338 .rel.plt
182 3 7 0x4 0x8
183
184 [6] 1 6 0x8049348 0x1348 0x3 .init
185 0 0 0x4 0
186
187 [7] 1 6 0x804934c 0x134c 0x680 .plt
188 0 0 0x4 0x4
189
190 [8] 1 6 0x80499cc 0x19cc 0x3c56f .text
191 0 0 0x4 0
192
193 [9] 1 6 0x8085f3c 0x3df3c 0x3 .fini
194 0 0 0x4 0
195
196 [10] 1 2 0x8085f40 0x3df40 0x69c .rodata
197 0 0 0x4 0
198
199 [11] 1 2 0x80865dc 0x3e5dc 0xd51 .rodata1
200 0 0 0x4 0
201
202 [12] 1 3 0x8088330 0x3f330 0x20afc .data
203 0 0 0x4 0
204
205 [13] 1 3 0x80a8e2c 0x5fe2c 0x89d .data1
206 0 0 0x4 0
207
208 [14] 1 3 0x80a96cc 0x606cc 0x1a8 .got
209 0 0 0x4 0x4
210
211 [15] 6 3 0x80a9874 0x60874 0x80 .dynamic
212 4 0 0x4 0x8
213
214 [16] 8 3 0x80c6800 0x7d800 0 .bss
215 0 0 0x4 0
216
217 [17] 2 0 0 0x7d800 0x9b90 .symtab
218 18 371 0x4 0x10
219
220 [18] 3 0 0 0x87390 0x8526 .strtab
221 0 0 0x1 0
222
223 [19] 3 0 0 0x8f8b6 0x93 .shstrtab
224 0 0 0x1 0
225
226 [20] 1 0 0 0x8f949 0x68b7 .comment
227 0 0 0x1 0
228
229 [21] 1 3 0x80a98f4 0x608f4 0x1cf0c .data
230 0 0 0x4 0
231
232 * This is an example of how the file header is changed. "Shoff" is
233 * the section header offset within the file. Since that table is
234 * after the new .data section, it is moved. "Shnum" is the number of
235 * sections, which we increment.
236 *
237 * "Phoff" is the file offset to the program header. "Phentsize" and
238 * "Shentsz" are the program and section header entries sizes respectively.
239 * These can be larger than the apparent struct sizes.
240
241 raid:/nfs/raid/src/dist-18.56/src> dump -f temacs
242
243 temacs:
244
245 **** ELF HEADER ****
246 Class Data Type Machine Version
247 Entry Phoff Shoff Flags Ehsize
248 Phentsize Phnum Shentsz Shnum Shstrndx
249
250 1 1 2 3 1
251 0x80499cc 0x34 0x792f4 0 0x34
252 0x20 5 0x28 21 19
253
254 raid:/nfs/raid/src/dist-18.56/src> dump -f xemacs
255
256 xemacs:
257
258 **** ELF HEADER ****
259 Class Data Type Machine Version
260 Entry Phoff Shoff Flags Ehsize
261 Phentsize Phnum Shentsz Shnum Shstrndx
262
263 1 1 2 3 1
264 0x80499cc 0x34 0x96200 0 0x34
265 0x20 5 0x28 22 19
266
267 * These are the program headers. "Offset" is the file offset to the
268 * segment. "Vaddr" is the memory load address. "Filesz" is the
269 * segment size as it appears in the file, and "Memsz" is the size in
270 * memory. Below, the third segment is the code and the fourth is the
271 * data: the difference between Filesz and Memsz is .bss
272
273 raid:/nfs/raid/src/dist-18.56/src> dump -o temacs
274
275 temacs:
276 ***** PROGRAM EXECUTION HEADER *****
277 Type Offset Vaddr Paddr
278 Filesz Memsz Flags Align
279
280 6 0x34 0x8048034 0
281 0xa0 0xa0 5 0
282
283 3 0xd4 0 0
284 0x13 0 4 0
285
286 1 0x34 0x8048034 0
287 0x3f2f9 0x3f2f9 5 0x1000
288
289 1 0x3f330 0x8088330 0
290 0x215c4 0x25a60 7 0x1000
291
292 2 0x60874 0x80a9874 0
293 0x80 0 7 0
294
295 raid:/nfs/raid/src/dist-18.56/src> dump -o xemacs
296
297 xemacs:
298 ***** PROGRAM EXECUTION HEADER *****
299 Type Offset Vaddr Paddr
300 Filesz Memsz Flags Align
301
302 6 0x34 0x8048034 0
303 0xa0 0xa0 5 0
304
305 3 0xd4 0 0
306 0x13 0 4 0
307
308 1 0x34 0x8048034 0
309 0x3f2f9 0x3f2f9 5 0x1000
310
311 1 0x3f330 0x8088330 0
312 0x3e4d0 0x3e4d0 7 0x1000
313
314 2 0x60874 0x80a9874 0
315 0x80 0 7 0
316
317
318 */
319
320 /* Modified by wtien@urbana.mcd.mot.com of Motorola Inc.
321 *
322 * The above mechanism does not work if the unexeced ELF file is being
323 * re-layout by other applications (such as `strip'). All the applications
324 * that re-layout the internal of ELF will layout all sections in ascending
325 * order of their file offsets. After the re-layout, the data2 section will
326 * still be the LAST section in the section header vector, but its file offset
327 * is now being pushed far away down, and causes part of it not to be mapped
328 * in (ie. not covered by the load segment entry in PHDR vector), therefore
329 * causes the new binary to fail.
330 *
331 * The solution is to modify the unexec algorithm to insert the new data2
332 * section header right before the new bss section header, so their file
333 * offsets will be in the ascending order. Since some of the section's (all
334 * sections AFTER the bss section) indexes are now changed, we also need to
335 * modify some fields to make them point to the right sections. This is done
336 * by macro PATCH_INDEX. All the fields that need to be patched are:
337 *
338 * 1. ELF header e_shstrndx field.
339 * 2. section header sh_link and sh_info field.
340 * 3. symbol table entry st_shndx field.
341 *
342 * The above example now should look like:
343
344 **** SECTION HEADER TABLE ****
345 [No] Type Flags Addr Offset Size Name
346 Link Info Adralgn Entsize
347
348 [1] 1 2 0x80480d4 0xd4 0x13 .interp
349 0 0 0x1 0
350
351 [2] 5 2 0x80480e8 0xe8 0x388 .hash
352 3 0 0x4 0x4
353
354 [3] 11 2 0x8048470 0x470 0x7f0 .dynsym
355 4 1 0x4 0x10
356
357 [4] 3 2 0x8048c60 0xc60 0x3ad .dynstr
358 0 0 0x1 0
359
360 [5] 9 2 0x8049010 0x1010 0x338 .rel.plt
361 3 7 0x4 0x8
362
363 [6] 1 6 0x8049348 0x1348 0x3 .init
364 0 0 0x4 0
365
366 [7] 1 6 0x804934c 0x134c 0x680 .plt
367 0 0 0x4 0x4
368
369 [8] 1 6 0x80499cc 0x19cc 0x3c56f .text
370 0 0 0x4 0
371
372 [9] 1 6 0x8085f3c 0x3df3c 0x3 .fini
373 0 0 0x4 0
374
375 [10] 1 2 0x8085f40 0x3df40 0x69c .rodata
376 0 0 0x4 0
377
378 [11] 1 2 0x80865dc 0x3e5dc 0xd51 .rodata1
379 0 0 0x4 0
380
381 [12] 1 3 0x8088330 0x3f330 0x20afc .data
382 0 0 0x4 0
383
384 [13] 1 3 0x80a8e2c 0x5fe2c 0x89d .data1
385 0 0 0x4 0
386
387 [14] 1 3 0x80a96cc 0x606cc 0x1a8 .got
388 0 0 0x4 0x4
389
390 [15] 6 3 0x80a9874 0x60874 0x80 .dynamic
391 4 0 0x4 0x8
392
393 [16] 1 3 0x80a98f4 0x608f4 0x1cf0c .data
394 0 0 0x4 0
395
396 [17] 8 3 0x80c6800 0x7d800 0 .bss
397 0 0 0x4 0
398
399 [18] 2 0 0 0x7d800 0x9b90 .symtab
400 19 371 0x4 0x10
401
402 [19] 3 0 0 0x87390 0x8526 .strtab
403 0 0 0x1 0
404
405 [20] 3 0 0 0x8f8b6 0x93 .shstrtab
406 0 0 0x1 0
407
408 [21] 1 0 0 0x8f949 0x68b7 .comment
409 0 0 0x1 0
410
411 */
412
413 /* More mods, by Jack Repenning <jackr@sgi.com>, Fri Aug 11 15:45:52 1995
414
415 Same algorithm as immediately above. However, the detailed
416 calculations of the various locations needed significant
417 overhaul.
418
419 At the point of the old .bss, the file offsets and the memory
420 addresses do distinct, slightly snaky things:
421
422 offset of .bss is meaningless and unpredictable
423 addr of .bss is meaningful
424 alignment of .bss is important to addr, so there may be a small
425 gap in address range before start of bss
426 offset of next section is rounded up modulo 0x1000
427 the hole so-introduced is zero-filled, so it can be mapped in as
428 the first partial-page of bss (the rest of the bss is mapped from
429 /dev/zero)
430 I suppose you could view this not as a hole, but as the beginning
431 of the bss, actually present in the file. But you should not
432 push that worldview too far, as the linker still knows that the
433 "offset" claimed for the bss is unused, and seems not always
434 careful about setting it.
435
436 We are doing all our tricks at this same rather complicated
437 location (isn't life fun?):
438
439 insert a new data section to contain now-initialized old bss and
440 heap
441 define a zero-length bss just so there is one
442
443 The offset of the new data section is dictated by its current
444 address (which, of course, we want also to be its addr): the
445 loader maps in the whole file region containing old data, rodata,
446 got, and new data as a single mapped segment, starting at the
447 address of the first chunk; the rest have to be laid out in the
448 file such that the map into the right spots. That is:
449
450 offset(newdata) ==
451 addrInRunningMemory(newdata)-aIRM(olddata)
452 + offset(oldData)
453
454 This would not necessarily match the oldbss offset, even if it
455 were carefully calculated! We must compute this.
456
457 The linker that built temacs has also already arranged that
458 olddata is properly page-aligned (not necessarily beginning on a
459 page, but rather that a page's worth of the low bits of addr and
460 offset match). We preserve this.
461
462 addr(bss) is alignment-constrained from the end of the new data.
463 Since we base endof(newdata) on sbrk(), we have a page boundary
464 (in both offset and addr) and meet any alignment constraint,
465 needing no alignment adjustment of this location and no
466 mini-hole. Or, if you like, we've allowed sbrk() to "compute"
467 the mini-hole size for us.
468
469 That puts newbss beginning on a page boundary, both in offset and
470 addr. (offset(bss) is still meaningless, but what the heck,
471 we'll fix it up.)
472
473 Since newbss has zero length, and its offset (however
474 meaningless) is page aligned, we place the next section exactly
475 there, with no hole needed to restore page alignment.
476
477 So, the shift for all sections beyond the playing field is:
478
479 new_bss_addr - roundup(old_bss_addr,0x1000)
480
481 */
482
483
484 #include <sys/types.h>
485 #include <stdio.h>
486 #include <sys/stat.h>
487 #include <memory.h>
488 #include <string.h>
489 #include <errno.h>
490 #include <unistd.h>
491 #include <fcntl.h>
492 #include <elf.h>
493 #include <sym.h> /* for HDRR declaration */
494 #include <sys/mman.h>
495
496 #ifndef emacs
497 #define fatal(a, b, c) fprintf(stderr, a, b, c), exit(1)
498 #else
499 extern void fatal(char *, ...);
500 #endif
501
502 /* Get the address of a particular section or program header entry,
503 * accounting for the size of the entries.
504 */
505
506 #define OLD_SECTION_H(n) \
507 (*(Elf32_Shdr *) ((byte *) old_section_h + old_file_h->e_shentsize * (n)))
508 #define NEW_SECTION_H(n) \
509 (*(Elf32_Shdr *) ((byte *) new_section_h + new_file_h->e_shentsize * (n)))
510 #define OLD_PROGRAM_H(n) \
511 (*(Elf32_Phdr *) ((byte *) old_program_h + old_file_h->e_phentsize * (n)))
512 #define NEW_PROGRAM_H(n) \
513 (*(Elf32_Phdr *) ((byte *) new_program_h + new_file_h->e_phentsize * (n)))
514
515 #define PATCH_INDEX(n) \
516 do { \
517 if ((n) >= old_bss_index) \
518 (n)++; } while (0)
519 typedef unsigned char byte;
520
521 /* Round X up to a multiple of Y. */
522
523 int
524 round_up (x, y)
525 int x, y;
526 {
527 int rem = x % y;
528 if (rem == 0)
529 return x;
530 return x - rem + y;
531 }
532
533 /* Return the index of the section named NAME.
534 SECTION_NAMES, FILE_NAME and FILE_H give information
535 about the file we are looking in.
536
537 If we don't find the section NAME, that is a fatal error
538 if NOERROR is 0; we return -1 if NOERROR is nonzero. */
539
540 static int
541 find_section (name, section_names, file_name, old_file_h, old_section_h, noerror)
542 char *name;
543 char *section_names;
544 char *file_name;
545 Elf32_Ehdr *old_file_h;
546 Elf32_Shdr *old_section_h;
547 int noerror;
548 {
549 int idx;
550
551 for (idx = 1; idx < old_file_h->e_shnum; idx++)
552 {
553 #ifdef DEBUG
554 fprintf (stderr, "Looking for %s - found %s\n", name,
555 section_names + OLD_SECTION_H (idx).sh_name);
556 #endif
557 if (!strcmp (section_names + OLD_SECTION_H (idx).sh_name,
558 name))
559 break;
560 }
561 if (idx == old_file_h->e_shnum)
562 {
563 if (noerror)
564 return -1;
565 else
566 fatal ("Can't find .bss in %s.\n", file_name, 0);
567 }
568
569 return idx;
570 }
571
572 /* ****************************************************************
573 * unexec
574 *
575 * driving logic.
576 *
577 * In ELF, this works by replacing the old .bss section with a new
578 * .data section, and inserting an empty .bss immediately afterwards.
579 *
580 */
581 void
582 unexec (new_name, old_name, data_start, bss_start, entry_address)
583 char *new_name, *old_name;
584 unsigned data_start, bss_start, entry_address;
585 {
586 extern unsigned int bss_end;
587 int new_file, old_file, new_file_size;
588
589 /* Pointers to the base of the image of the two files. */
590 caddr_t old_base, new_base;
591
592 /* Pointers to the file, program and section headers for the old and new
593 files. */
594 Elf32_Ehdr *old_file_h, *new_file_h;
595 Elf32_Phdr *old_program_h, *new_program_h;
596 Elf32_Shdr *old_section_h, *new_section_h;
597
598 /* Point to the section name table in the old file. */
599 char *old_section_names;
600
601 Elf32_Addr old_bss_addr, new_bss_addr;
602 Elf32_Word old_bss_size, new_data2_size;
603 Elf32_Off new_data2_offset;
604 Elf32_Addr new_data2_addr;
605 Elf32_Addr new_offsets_shift;
606
607 int n, nn, old_bss_index, old_data_index, new_data2_index;
608 int old_mdebug_index;
609 struct stat stat_buf;
610
611 /* Open the old file & map it into the address space. */
612
613 old_file = open (old_name, O_RDONLY);
614
615 if (old_file < 0)
616 fatal ("Can't open %s for reading: errno %d\n", old_name, errno);
617
618 if (fstat (old_file, &stat_buf) == -1)
619 fatal ("Can't fstat(%s): errno %d\n", old_name, errno);
620
621 old_base = mmap (0, stat_buf.st_size, PROT_READ, MAP_SHARED, old_file, 0);
622
623 if (old_base == (caddr_t) -1)
624 fatal ("Can't mmap(%s): errno %d\n", old_name, errno);
625
626 #ifdef DEBUG
627 fprintf (stderr, "mmap(%s, %x) -> %x\n", old_name, stat_buf.st_size,
628 old_base);
629 #endif
630
631 /* Get pointers to headers & section names. */
632
633 old_file_h = (Elf32_Ehdr *) old_base;
634 old_program_h = (Elf32_Phdr *) ((byte *) old_base + old_file_h->e_phoff);
635 old_section_h = (Elf32_Shdr *) ((byte *) old_base + old_file_h->e_shoff);
636 old_section_names
637 = (char *) old_base + OLD_SECTION_H (old_file_h->e_shstrndx).sh_offset;
638
639 /* Find the mdebug section, if any. */
640
641 old_mdebug_index = find_section (".mdebug", old_section_names,
642 old_name, old_file_h, old_section_h, 1);
643
644 /* Find the old .bss section. */
645
646 old_bss_index = find_section (".bss", old_section_names,
647 old_name, old_file_h, old_section_h, 0);
648
649 /* Find the old .data section. Figure out parameters of
650 the new data2 and bss sections. */
651
652 old_data_index = find_section (".data", old_section_names,
653 old_name, old_file_h, old_section_h, 0);
654
655 old_bss_addr = OLD_SECTION_H (old_bss_index).sh_addr;
656 old_bss_size = OLD_SECTION_H (old_bss_index).sh_size;
657 #if defined(emacs) || !defined(DEBUG)
658 bss_end = (unsigned int) sbrk (0);
659 new_bss_addr = (Elf32_Addr) bss_end;
660 #else
661 new_bss_addr = old_bss_addr + old_bss_size + 0x1234;
662 #endif
663 new_data2_addr = old_bss_addr;
664 new_data2_size = new_bss_addr - old_bss_addr;
665 new_data2_offset = OLD_SECTION_H (old_data_index).sh_offset +
666 (new_data2_addr - OLD_SECTION_H (old_data_index).sh_addr);
667 new_offsets_shift = new_bss_addr -
668 ((old_bss_addr & ~0xfff) + ((old_bss_addr & 0xfff) ? 0x1000 : 0));
669
670 #ifdef DEBUG
671 fprintf (stderr, "old_bss_index %d\n", old_bss_index);
672 fprintf (stderr, "old_bss_addr %x\n", old_bss_addr);
673 fprintf (stderr, "old_bss_size %x\n", old_bss_size);
674 fprintf (stderr, "new_bss_addr %x\n", new_bss_addr);
675 fprintf (stderr, "new_data2_addr %x\n", new_data2_addr);
676 fprintf (stderr, "new_data2_size %x\n", new_data2_size);
677 fprintf (stderr, "new_data2_offset %x\n", new_data2_offset);
678 fprintf (stderr, "new_offsets_shift %x\n", new_offsets_shift);
679 #endif
680
681 if ((unsigned) new_bss_addr < (unsigned) old_bss_addr + old_bss_size)
682 fatal (".bss shrank when undumping???\n", 0, 0);
683
684 /* Set the output file to the right size and mmap it. Set
685 pointers to various interesting objects. stat_buf still has
686 old_file data. */
687
688 new_file = open (new_name, O_RDWR | O_CREAT, 0666);
689 if (new_file < 0)
690 fatal ("Can't creat (%s): errno %d\n", new_name, errno);
691
692 new_file_size = stat_buf.st_size /* old file size */
693 + old_file_h->e_shentsize /* one new section header */
694 + new_offsets_shift; /* trailing section shift */
695
696 if (ftruncate (new_file, new_file_size))
697 fatal ("Can't ftruncate (%s): errno %d\n", new_name, errno);
698
699 new_base = mmap (0, new_file_size, PROT_READ | PROT_WRITE, MAP_SHARED,
700 new_file, 0);
701
702 if (new_base == (caddr_t) -1)
703 fatal ("Can't mmap (%s): errno %d\n", new_name, errno);
704
705 new_file_h = (Elf32_Ehdr *) new_base;
706 new_program_h = (Elf32_Phdr *) ((byte *) new_base + old_file_h->e_phoff);
707 new_section_h
708 = (Elf32_Shdr *) ((byte *) new_base + old_file_h->e_shoff
709 + new_offsets_shift);
710
711 /* Make our new file, program and section headers as copies of the
712 originals. */
713
714 memcpy (new_file_h, old_file_h, old_file_h->e_ehsize);
715 memcpy (new_program_h, old_program_h,
716 old_file_h->e_phnum * old_file_h->e_phentsize);
717
718 /* Modify the e_shstrndx if necessary. */
719 PATCH_INDEX (new_file_h->e_shstrndx);
720
721 /* Fix up file header. We'll add one section. Section header is
722 further away now. */
723
724 new_file_h->e_shoff += new_offsets_shift;
725 new_file_h->e_shnum += 1;
726
727 #ifdef DEBUG
728 fprintf (stderr, "Old section offset %x\n", old_file_h->e_shoff);
729 fprintf (stderr, "Old section count %d\n", old_file_h->e_shnum);
730 fprintf (stderr, "New section offset %x\n", new_file_h->e_shoff);
731 fprintf (stderr, "New section count %d\n", new_file_h->e_shnum);
732 #endif
733
734 /* Fix up a new program header. Extend the writable data segment so
735 that the bss area is covered too. Find that segment by looking
736 for a segment that ends just before the .bss area. Make sure
737 that no segments are above the new .data2. Put a loop at the end
738 to adjust the offset and address of any segment that is above
739 data2, just in case we decide to allow this later. */
740
741 for (n = new_file_h->e_phnum - 1; n >= 0; n--)
742 {
743 /* Compute maximum of all requirements for alignment of section. */
744 int alignment = (NEW_PROGRAM_H (n)).p_align;
745 if ((OLD_SECTION_H (old_bss_index)).sh_addralign > alignment)
746 alignment = OLD_SECTION_H (old_bss_index).sh_addralign;
747
748 /* Supposedly this condition is okay for the SGI. */
749 #if 0
750 if (NEW_PROGRAM_H (n).p_vaddr + NEW_PROGRAM_H (n).p_filesz > old_bss_addr)
751 fatal ("Program segment above .bss in %s\n", old_name, 0);
752 #endif
753
754 if (NEW_PROGRAM_H (n).p_type == PT_LOAD
755 && (round_up ((NEW_PROGRAM_H (n)).p_vaddr
756 + (NEW_PROGRAM_H (n)).p_filesz,
757 alignment)
758 == round_up (old_bss_addr, alignment)))
759 break;
760 }
761 if (n < 0)
762 fatal ("Couldn't find segment next to .bss in %s\n", old_name, 0);
763
764 NEW_PROGRAM_H (n).p_filesz += new_offsets_shift;
765 NEW_PROGRAM_H (n).p_memsz = NEW_PROGRAM_H (n).p_filesz;
766
767 #if 1 /* Maybe allow section after data2 - does this ever happen? */
768 for (n = new_file_h->e_phnum - 1; n >= 0; n--)
769 {
770 if (NEW_PROGRAM_H (n).p_vaddr
771 && NEW_PROGRAM_H (n).p_vaddr >= new_data2_addr)
772 NEW_PROGRAM_H (n).p_vaddr += new_offsets_shift - old_bss_size;
773
774 if (NEW_PROGRAM_H (n).p_offset >= new_data2_offset)
775 NEW_PROGRAM_H (n).p_offset += new_offsets_shift;
776 }
777 #endif
778
779 /* Fix up section headers based on new .data2 section. Any section
780 whose offset or virtual address is after the new .data2 section
781 gets its value adjusted. .bss size becomes zero and new address
782 is set. data2 section header gets added by copying the existing
783 .data header and modifying the offset, address and size. */
784 for (old_data_index = 1; old_data_index < old_file_h->e_shnum;
785 old_data_index++)
786 if (!strcmp (old_section_names + OLD_SECTION_H (old_data_index).sh_name,
787 ".data"))
788 break;
789 if (old_data_index == old_file_h->e_shnum)
790 fatal ("Can't find .data in %s.\n", old_name, 0);
791
792 /* Walk through all section headers, insert the new data2 section right
793 before the new bss section. */
794 for (n = 1, nn = 1; n < old_file_h->e_shnum; n++, nn++)
795 {
796 caddr_t src;
797
798 /* XEmacs change: */
799 if (n < old_bss_index)
800 {
801 memcpy (&NEW_SECTION_H (nn), &OLD_SECTION_H (n),
802 old_file_h->e_shentsize);
803
804 }
805 else if (n == old_bss_index)
806 {
807
808 /* If it is bss section, insert the new data2 section before it. */
809 /* Steal the data section header for this data2 section. */
810 memcpy (&NEW_SECTION_H (nn), &OLD_SECTION_H (old_data_index),
811 new_file_h->e_shentsize);
812
813 NEW_SECTION_H (nn).sh_addr = new_data2_addr;
814 NEW_SECTION_H (nn).sh_offset = new_data2_offset;
815 NEW_SECTION_H (nn).sh_size = new_data2_size;
816 /* Use the bss section's alignment. This will assure that the
817 new data2 section always be placed in the same spot as the old
818 bss section by any other application. */
819 NEW_SECTION_H (nn).sh_addralign = OLD_SECTION_H (n).sh_addralign;
820
821 /* Now copy over what we have in the memory now. */
822 memcpy (NEW_SECTION_H (nn).sh_offset + new_base,
823 (caddr_t) OLD_SECTION_H (n).sh_addr,
824 new_data2_size);
825 nn++;
826 memcpy (&NEW_SECTION_H (nn), &OLD_SECTION_H (n),
827 old_file_h->e_shentsize);
828
829 /* The new bss section's size is zero, and its file offset and virtual
830 address should be off by NEW_OFFSETS_SHIFT. */
831 NEW_SECTION_H (nn).sh_offset += new_offsets_shift;
832 NEW_SECTION_H (nn).sh_addr = new_bss_addr;
833 /* Let the new bss section address alignment be the same as the
834 section address alignment followed the old bss section, so
835 this section will be placed in exactly the same place. */
836 NEW_SECTION_H (nn).sh_addralign = OLD_SECTION_H (nn).sh_addralign;
837 NEW_SECTION_H (nn).sh_size = 0;
838 }
839 else /* n > old_bss_index */
840 memcpy (&NEW_SECTION_H (nn), &OLD_SECTION_H (n),
841 old_file_h->e_shentsize);
842
843 /* Any section that was original placed AFTER the bss
844 section must now be adjusted by NEW_OFFSETS_SHIFT. */
845
846 if (NEW_SECTION_H (nn).sh_offset >= new_data2_offset)
847 NEW_SECTION_H (nn).sh_offset += new_offsets_shift;
848
849 /* If any section hdr refers to the section after the new .data
850 section, make it refer to next one because we have inserted
851 a new section in between. */
852
853 PATCH_INDEX (NEW_SECTION_H (nn).sh_link);
854 /* For symbol tables, info is a symbol table index,
855 so don't change it. */
856 if (NEW_SECTION_H (nn).sh_type != SHT_SYMTAB
857 && NEW_SECTION_H (nn).sh_type != SHT_DYNSYM)
858 PATCH_INDEX (NEW_SECTION_H (nn).sh_info);
859
860 /* Now, start to copy the content of sections. */
861 if (NEW_SECTION_H (nn).sh_type == SHT_NULL
862 || NEW_SECTION_H (nn).sh_type == SHT_NOBITS)
863 continue;
864
865 /* Write out the sections. .data and .data1 (and data2, called
866 ".data" in the strings table) get copied from the current process
867 instead of the old file. */
868 if (!strcmp (old_section_names + NEW_SECTION_H (n).sh_name, ".data")
869 || !strcmp (old_section_names + NEW_SECTION_H (n).sh_name, ".data1")
870 || !strcmp (old_section_names + NEW_SECTION_H (n).sh_name, ".got"))
871 src = (caddr_t) OLD_SECTION_H (n).sh_addr;
872 else
873 src = old_base + OLD_SECTION_H (n).sh_offset;
874
875 memcpy (NEW_SECTION_H (nn).sh_offset + new_base, src,
876 NEW_SECTION_H (nn).sh_size);
877
878 /* Adjust the HDRR offsets in .mdebug and copy the
879 line data if it's in its usual 'hole' in the object.
880 Makes the new file debuggable with dbx.
881 patches up two problems: the absolute file offsets
882 in the HDRR record of .mdebug (see /usr/include/syms.h), and
883 the ld bug that gets the line table in a hole in the
884 elf file rather than in the .mdebug section proper.
885 David Anderson. davea@sgi.com Jan 16,1994. */
886 if (n == old_mdebug_index)
887 {
888 #define MDEBUGADJUST(__ct,__fileaddr) \
889 if (n_phdrr->__ct > 0) \
890 { \
891 n_phdrr->__fileaddr += movement; \
892 }
893
894 HDRR * o_phdrr = (HDRR *)((byte *)old_base + OLD_SECTION_H (n).sh_offset);
895 HDRR * n_phdrr = (HDRR *)((byte *)new_base + NEW_SECTION_H (nn).sh_offset);
896 unsigned movement = new_offsets_shift;
897
898 MDEBUGADJUST (idnMax, cbDnOffset);
899 MDEBUGADJUST (ipdMax, cbPdOffset);
900 MDEBUGADJUST (isymMax, cbSymOffset);
901 MDEBUGADJUST (ioptMax, cbOptOffset);
902 MDEBUGADJUST (iauxMax, cbAuxOffset);
903 MDEBUGADJUST (issMax, cbSsOffset);
904 MDEBUGADJUST (issExtMax, cbSsExtOffset);
905 MDEBUGADJUST (ifdMax, cbFdOffset);
906 MDEBUGADJUST (crfd, cbRfdOffset);
907 MDEBUGADJUST (iextMax, cbExtOffset);
908 /* The Line Section, being possible off in a hole of the object,
909 requires special handling. */
910 if (n_phdrr->cbLine > 0)
911 {
912 if (o_phdrr->cbLineOffset > (OLD_SECTION_H (n).sh_offset
913 + OLD_SECTION_H (n).sh_size))
914 {
915 /* line data is in a hole in elf. do special copy and adjust
916 for this ld mistake.
917 */
918 n_phdrr->cbLineOffset += movement;
919
920 memcpy (n_phdrr->cbLineOffset + new_base,
921 o_phdrr->cbLineOffset + old_base, n_phdrr->cbLine);
922 }
923 else
924 {
925 /* somehow line data is in .mdebug as it is supposed to be. */
926 MDEBUGADJUST (cbLine, cbLineOffset);
927 }
928 }
929 }
930
931 /* If it is the symbol table, its st_shndx field needs to be patched. */
932 if (NEW_SECTION_H (nn).sh_type == SHT_SYMTAB
933 || NEW_SECTION_H (nn).sh_type == SHT_DYNSYM)
934 {
935 Elf32_Shdr *spt = &NEW_SECTION_H (nn);
936 unsigned int num = spt->sh_size / spt->sh_entsize;
937 Elf32_Sym * sym = (Elf32_Sym *) (NEW_SECTION_H (nn).sh_offset
938 + new_base);
939 for (; num--; sym++)
940 {
941 if (sym->st_shndx == SHN_UNDEF
942 || sym->st_shndx == SHN_ABS
943 || sym->st_shndx == SHN_COMMON)
944 continue;
945
946 PATCH_INDEX (sym->st_shndx);
947 }
948 }
949 }
950
951 /* Close the files and make the new file executable. */
952
953 if (close (old_file))
954 fatal ("Can't close (%s): errno %d\n", old_name, errno);
955
956 if (close (new_file))
957 fatal ("Can't close (%s): errno %d\n", new_name, errno);
958
959 if (stat (new_name, &stat_buf) == -1)
960 fatal ("Can't stat (%s): errno %d\n", new_name, errno);
961
962 n = umask (777);
963 umask (n);
964 stat_buf.st_mode |= 0111 & ~n;
965 if (chmod (new_name, stat_buf.st_mode) == -1)
966 fatal ("Can't chmod (%s): errno %d\n", new_name, errno);
967 }