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Merge IRIX debugging info patch from unexsgi.c
[bpt/emacs.git] / src / unexelf.c
1 /* Copyright (C) 1985, 1986, 1987, 1988, 1990, 1992
2 Free Software Foundation, Inc.
3
4 This file is part of GNU Emacs.
5
6 GNU Emacs is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
9 any later version.
10
11 GNU Emacs is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with GNU Emacs; 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 In other words, you are welcome to use, share and improve this program.
22 You are forbidden to forbid anyone else to use, share and improve
23 what you give them. Help stamp out software-hoarding! */
24
25
26 /*
27 * unexec.c - Convert a running program into an a.out file.
28 *
29 * Author: Spencer W. Thomas
30 * Computer Science Dept.
31 * University of Utah
32 * Date: Tue Mar 2 1982
33 * Modified heavily since then.
34 *
35 * Synopsis:
36 * unexec (new_name, old_name, data_start, bss_start, entry_address)
37 * char *new_name, *old_name;
38 * unsigned data_start, bss_start, entry_address;
39 *
40 * Takes a snapshot of the program and makes an a.out format file in the
41 * file named by the string argument new_name.
42 * If old_name is non-NULL, the symbol table will be taken from the given file.
43 * On some machines, an existing old_name file is required.
44 *
45 * The boundaries within the a.out file may be adjusted with the data_start
46 * and bss_start arguments. Either or both may be given as 0 for defaults.
47 *
48 * Data_start gives the boundary between the text segment and the data
49 * segment of the program. The text segment can contain shared, read-only
50 * program code and literal data, while the data segment is always unshared
51 * and unprotected. Data_start gives the lowest unprotected address.
52 * The value you specify may be rounded down to a suitable boundary
53 * as required by the machine you are using.
54 *
55 * Specifying zero for data_start means the boundary between text and data
56 * should not be the same as when the program was loaded.
57 * If NO_REMAP is defined, the argument data_start is ignored and the
58 * segment boundaries are never changed.
59 *
60 * Bss_start indicates how much of the data segment is to be saved in the
61 * a.out file and restored when the program is executed. It gives the lowest
62 * unsaved address, and is rounded up to a page boundary. The default when 0
63 * is given assumes that the entire data segment is to be stored, including
64 * the previous data and bss as well as any additional storage allocated with
65 * break (2).
66 *
67 * The new file is set up to start at entry_address.
68 *
69 * If you make improvements I'd like to get them too.
70 * harpo!utah-cs!thomas, thomas@Utah-20
71 *
72 */
73
74 /* Even more heavily modified by james@bigtex.cactus.org of Dell Computer Co.
75 * ELF support added.
76 *
77 * Basic theory: the data space of the running process needs to be
78 * dumped to the output file. Normally we would just enlarge the size
79 * of .data, scooting everything down. But we can't do that in ELF,
80 * because there is often something between the .data space and the
81 * .bss space.
82 *
83 * In the temacs dump below, notice that the Global Offset Table
84 * (.got) and the Dynamic link data (.dynamic) come between .data1 and
85 * .bss. It does not work to overlap .data with these fields.
86 *
87 * The solution is to create a new .data segment. This segment is
88 * filled with data from the current process. Since the contents of
89 * various sections refer to sections by index, the new .data segment
90 * is made the last in the table to avoid changing any existing index.
91
92 * This is an example of how the section headers are changed. "Addr"
93 * is a process virtual address. "Offset" is a file offset.
94
95 raid:/nfs/raid/src/dist-18.56/src> dump -h temacs
96
97 temacs:
98
99 **** SECTION HEADER TABLE ****
100 [No] Type Flags Addr Offset Size Name
101 Link Info Adralgn Entsize
102
103 [1] 1 2 0x80480d4 0xd4 0x13 .interp
104 0 0 0x1 0
105
106 [2] 5 2 0x80480e8 0xe8 0x388 .hash
107 3 0 0x4 0x4
108
109 [3] 11 2 0x8048470 0x470 0x7f0 .dynsym
110 4 1 0x4 0x10
111
112 [4] 3 2 0x8048c60 0xc60 0x3ad .dynstr
113 0 0 0x1 0
114
115 [5] 9 2 0x8049010 0x1010 0x338 .rel.plt
116 3 7 0x4 0x8
117
118 [6] 1 6 0x8049348 0x1348 0x3 .init
119 0 0 0x4 0
120
121 [7] 1 6 0x804934c 0x134c 0x680 .plt
122 0 0 0x4 0x4
123
124 [8] 1 6 0x80499cc 0x19cc 0x3c56f .text
125 0 0 0x4 0
126
127 [9] 1 6 0x8085f3c 0x3df3c 0x3 .fini
128 0 0 0x4 0
129
130 [10] 1 2 0x8085f40 0x3df40 0x69c .rodata
131 0 0 0x4 0
132
133 [11] 1 2 0x80865dc 0x3e5dc 0xd51 .rodata1
134 0 0 0x4 0
135
136 [12] 1 3 0x8088330 0x3f330 0x20afc .data
137 0 0 0x4 0
138
139 [13] 1 3 0x80a8e2c 0x5fe2c 0x89d .data1
140 0 0 0x4 0
141
142 [14] 1 3 0x80a96cc 0x606cc 0x1a8 .got
143 0 0 0x4 0x4
144
145 [15] 6 3 0x80a9874 0x60874 0x80 .dynamic
146 4 0 0x4 0x8
147
148 [16] 8 3 0x80a98f4 0x608f4 0x449c .bss
149 0 0 0x4 0
150
151 [17] 2 0 0 0x608f4 0x9b90 .symtab
152 18 371 0x4 0x10
153
154 [18] 3 0 0 0x6a484 0x8526 .strtab
155 0 0 0x1 0
156
157 [19] 3 0 0 0x729aa 0x93 .shstrtab
158 0 0 0x1 0
159
160 [20] 1 0 0 0x72a3d 0x68b7 .comment
161 0 0 0x1 0
162
163 raid:/nfs/raid/src/dist-18.56/src> dump -h xemacs
164
165 xemacs:
166
167 **** SECTION HEADER TABLE ****
168 [No] Type Flags Addr Offset Size Name
169 Link Info Adralgn Entsize
170
171 [1] 1 2 0x80480d4 0xd4 0x13 .interp
172 0 0 0x1 0
173
174 [2] 5 2 0x80480e8 0xe8 0x388 .hash
175 3 0 0x4 0x4
176
177 [3] 11 2 0x8048470 0x470 0x7f0 .dynsym
178 4 1 0x4 0x10
179
180 [4] 3 2 0x8048c60 0xc60 0x3ad .dynstr
181 0 0 0x1 0
182
183 [5] 9 2 0x8049010 0x1010 0x338 .rel.plt
184 3 7 0x4 0x8
185
186 [6] 1 6 0x8049348 0x1348 0x3 .init
187 0 0 0x4 0
188
189 [7] 1 6 0x804934c 0x134c 0x680 .plt
190 0 0 0x4 0x4
191
192 [8] 1 6 0x80499cc 0x19cc 0x3c56f .text
193 0 0 0x4 0
194
195 [9] 1 6 0x8085f3c 0x3df3c 0x3 .fini
196 0 0 0x4 0
197
198 [10] 1 2 0x8085f40 0x3df40 0x69c .rodata
199 0 0 0x4 0
200
201 [11] 1 2 0x80865dc 0x3e5dc 0xd51 .rodata1
202 0 0 0x4 0
203
204 [12] 1 3 0x8088330 0x3f330 0x20afc .data
205 0 0 0x4 0
206
207 [13] 1 3 0x80a8e2c 0x5fe2c 0x89d .data1
208 0 0 0x4 0
209
210 [14] 1 3 0x80a96cc 0x606cc 0x1a8 .got
211 0 0 0x4 0x4
212
213 [15] 6 3 0x80a9874 0x60874 0x80 .dynamic
214 4 0 0x4 0x8
215
216 [16] 8 3 0x80c6800 0x7d800 0 .bss
217 0 0 0x4 0
218
219 [17] 2 0 0 0x7d800 0x9b90 .symtab
220 18 371 0x4 0x10
221
222 [18] 3 0 0 0x87390 0x8526 .strtab
223 0 0 0x1 0
224
225 [19] 3 0 0 0x8f8b6 0x93 .shstrtab
226 0 0 0x1 0
227
228 [20] 1 0 0 0x8f949 0x68b7 .comment
229 0 0 0x1 0
230
231 [21] 1 3 0x80a98f4 0x608f4 0x1cf0c .data
232 0 0 0x4 0
233
234 * This is an example of how the file header is changed. "Shoff" is
235 * the section header offset within the file. Since that table is
236 * after the new .data section, it is moved. "Shnum" is the number of
237 * sections, which we increment.
238 *
239 * "Phoff" is the file offset to the program header. "Phentsize" and
240 * "Shentsz" are the program and section header entries sizes respectively.
241 * These can be larger than the apparent struct sizes.
242
243 raid:/nfs/raid/src/dist-18.56/src> dump -f temacs
244
245 temacs:
246
247 **** ELF HEADER ****
248 Class Data Type Machine Version
249 Entry Phoff Shoff Flags Ehsize
250 Phentsize Phnum Shentsz Shnum Shstrndx
251
252 1 1 2 3 1
253 0x80499cc 0x34 0x792f4 0 0x34
254 0x20 5 0x28 21 19
255
256 raid:/nfs/raid/src/dist-18.56/src> dump -f xemacs
257
258 xemacs:
259
260 **** ELF HEADER ****
261 Class Data Type Machine Version
262 Entry Phoff Shoff Flags Ehsize
263 Phentsize Phnum Shentsz Shnum Shstrndx
264
265 1 1 2 3 1
266 0x80499cc 0x34 0x96200 0 0x34
267 0x20 5 0x28 22 19
268
269 * These are the program headers. "Offset" is the file offset to the
270 * segment. "Vaddr" is the memory load address. "Filesz" is the
271 * segment size as it appears in the file, and "Memsz" is the size in
272 * memory. Below, the third segment is the code and the fourth is the
273 * data: the difference between Filesz and Memsz is .bss
274
275 raid:/nfs/raid/src/dist-18.56/src> dump -o temacs
276
277 temacs:
278 ***** PROGRAM EXECUTION HEADER *****
279 Type Offset Vaddr Paddr
280 Filesz Memsz Flags Align
281
282 6 0x34 0x8048034 0
283 0xa0 0xa0 5 0
284
285 3 0xd4 0 0
286 0x13 0 4 0
287
288 1 0x34 0x8048034 0
289 0x3f2f9 0x3f2f9 5 0x1000
290
291 1 0x3f330 0x8088330 0
292 0x215c4 0x25a60 7 0x1000
293
294 2 0x60874 0x80a9874 0
295 0x80 0 7 0
296
297 raid:/nfs/raid/src/dist-18.56/src> dump -o xemacs
298
299 xemacs:
300 ***** PROGRAM EXECUTION HEADER *****
301 Type Offset Vaddr Paddr
302 Filesz Memsz Flags Align
303
304 6 0x34 0x8048034 0
305 0xa0 0xa0 5 0
306
307 3 0xd4 0 0
308 0x13 0 4 0
309
310 1 0x34 0x8048034 0
311 0x3f2f9 0x3f2f9 5 0x1000
312
313 1 0x3f330 0x8088330 0
314 0x3e4d0 0x3e4d0 7 0x1000
315
316 2 0x60874 0x80a9874 0
317 0x80 0 7 0
318
319
320 */
321 \f
322 /* Modified by wtien@urbana.mcd.mot.com of Motorola Inc.
323 *
324 * The above mechanism does not work if the unexeced ELF file is being
325 * re-layout by other applications (such as `strip'). All the applications
326 * that re-layout the internal of ELF will layout all sections in ascending
327 * order of their file offsets. After the re-layout, the data2 section will
328 * still be the LAST section in the section header vector, but its file offset
329 * is now being pushed far away down, and causes part of it not to be mapped
330 * in (ie. not covered by the load segment entry in PHDR vector), therefore
331 * causes the new binary to fail.
332 *
333 * The solution is to modify the unexec algorithm to insert the new data2
334 * section header right before the new bss section header, so their file
335 * offsets will be in the ascending order. Since some of the section's (all
336 * sections AFTER the bss section) indexes are now changed, we also need to
337 * modify some fields to make them point to the right sections. This is done
338 * by macro PATCH_INDEX. All the fields that need to be patched are:
339 *
340 * 1. ELF header e_shstrndx field.
341 * 2. section header sh_link and sh_info field.
342 * 3. symbol table entry st_shndx field.
343 *
344 * The above example now should look like:
345
346 **** SECTION HEADER TABLE ****
347 [No] Type Flags Addr Offset Size Name
348 Link Info Adralgn Entsize
349
350 [1] 1 2 0x80480d4 0xd4 0x13 .interp
351 0 0 0x1 0
352
353 [2] 5 2 0x80480e8 0xe8 0x388 .hash
354 3 0 0x4 0x4
355
356 [3] 11 2 0x8048470 0x470 0x7f0 .dynsym
357 4 1 0x4 0x10
358
359 [4] 3 2 0x8048c60 0xc60 0x3ad .dynstr
360 0 0 0x1 0
361
362 [5] 9 2 0x8049010 0x1010 0x338 .rel.plt
363 3 7 0x4 0x8
364
365 [6] 1 6 0x8049348 0x1348 0x3 .init
366 0 0 0x4 0
367
368 [7] 1 6 0x804934c 0x134c 0x680 .plt
369 0 0 0x4 0x4
370
371 [8] 1 6 0x80499cc 0x19cc 0x3c56f .text
372 0 0 0x4 0
373
374 [9] 1 6 0x8085f3c 0x3df3c 0x3 .fini
375 0 0 0x4 0
376
377 [10] 1 2 0x8085f40 0x3df40 0x69c .rodata
378 0 0 0x4 0
379
380 [11] 1 2 0x80865dc 0x3e5dc 0xd51 .rodata1
381 0 0 0x4 0
382
383 [12] 1 3 0x8088330 0x3f330 0x20afc .data
384 0 0 0x4 0
385
386 [13] 1 3 0x80a8e2c 0x5fe2c 0x89d .data1
387 0 0 0x4 0
388
389 [14] 1 3 0x80a96cc 0x606cc 0x1a8 .got
390 0 0 0x4 0x4
391
392 [15] 6 3 0x80a9874 0x60874 0x80 .dynamic
393 4 0 0x4 0x8
394
395 [16] 1 3 0x80a98f4 0x608f4 0x1cf0c .data
396 0 0 0x4 0
397
398 [17] 8 3 0x80c6800 0x7d800 0 .bss
399 0 0 0x4 0
400
401 [18] 2 0 0 0x7d800 0x9b90 .symtab
402 19 371 0x4 0x10
403
404 [19] 3 0 0 0x87390 0x8526 .strtab
405 0 0 0x1 0
406
407 [20] 3 0 0 0x8f8b6 0x93 .shstrtab
408 0 0 0x1 0
409
410 [21] 1 0 0 0x8f949 0x68b7 .comment
411 0 0 0x1 0
412
413 */
414 \f
415 #include <sys/types.h>
416 #include <stdio.h>
417 #include <sys/stat.h>
418 #include <memory.h>
419 #include <string.h>
420 #include <errno.h>
421 #include <unistd.h>
422 #include <fcntl.h>
423 #if !defined (__NetBSD__) && !defined (__OpenBSD__)
424 #include <elf.h>
425 #endif
426 #include <sys/mman.h>
427 #if defined (__sony_news) && defined (_SYSTYPE_SYSV)
428 #include <sys/elf_mips.h>
429 #include <sym.h>
430 #endif /* __sony_news && _SYSTYPE_SYSV */
431 #if __sgi
432 #include <sym.h> /* for HDRR declaration */
433 #endif /* __sgi */
434
435 #if defined (__alpha__) && !defined (__NetBSD__) && !defined (__OpenBSD__)
436 /* Declare COFF debugging symbol table. This used to be in
437 /usr/include/sym.h, but this file is no longer included in Red Hat
438 5.0 and presumably in any other glibc 2.x based distribution. */
439 typedef struct {
440 short magic;
441 short vstamp;
442 int ilineMax;
443 int idnMax;
444 int ipdMax;
445 int isymMax;
446 int ioptMax;
447 int iauxMax;
448 int issMax;
449 int issExtMax;
450 int ifdMax;
451 int crfd;
452 int iextMax;
453 long cbLine;
454 long cbLineOffset;
455 long cbDnOffset;
456 long cbPdOffset;
457 long cbSymOffset;
458 long cbOptOffset;
459 long cbAuxOffset;
460 long cbSsOffset;
461 long cbSsExtOffset;
462 long cbFdOffset;
463 long cbRfdOffset;
464 long cbExtOffset;
465 } HDRR, *pHDRR;
466 #define cbHDRR sizeof(HDRR)
467 #define hdrNil ((pHDRR)0)
468 #endif
469
470 #ifdef __NetBSD__
471 /*
472 * NetBSD does not have normal-looking user-land ELF support.
473 */
474 # ifdef __alpha__
475 # define ELFSIZE 64
476 # else
477 # define ELFSIZE 32
478 # endif
479 # include <sys/exec_elf.h>
480
481 # define PT_LOAD Elf_pt_load
482 # define SHT_SYMTAB Elf_sht_symtab
483 # define SHT_DYNSYM Elf_sht_dynsym
484 # define SHT_NULL Elf_sht_null
485 # define SHT_NOBITS Elf_sht_nobits
486 # define SHT_REL Elf_sht_rel
487 # define SHT_RELA Elf_sht_rela
488
489 # define SHN_UNDEF Elf_eshn_undefined
490 # define SHN_ABS Elf_eshn_absolute
491 # define SHN_COMMON Elf_eshn_common
492
493 /*
494 * The magic of picking the right size types is handled by the ELFSIZE
495 * definition above.
496 */
497 # ifdef __STDC__
498 # define ElfW(type) Elf_##type
499 # else
500 # define ElfW(type) Elf_/**/type
501 # endif
502
503 # ifdef __alpha__
504 # include <sys/exec_ecoff.h>
505 # define HDRR struct ecoff_symhdr
506 # define pHDRR HDRR *
507 # endif
508 #endif /* __NetBSD__ */
509
510 #ifdef __OpenBSD__
511 # include <sys/exec_elf.h>
512 #endif
513
514 #if __GNU_LIBRARY__ - 0 >= 6
515 # include <link.h> /* get ElfW etc */
516 #endif
517
518 #ifndef ElfW
519 # ifdef __STDC__
520 # define ElfW(type) Elf32_##type
521 # else
522 # define ElfW(type) Elf32_/**/type
523 # endif
524 #endif
525
526 #ifndef emacs
527 #define fatal(a, b, c) fprintf (stderr, a, b, c), exit (1)
528 #else
529 #include <config.h>
530 extern void fatal (char *, ...);
531 #endif
532
533 #ifndef ELF_BSS_SECTION_NAME
534 #define ELF_BSS_SECTION_NAME ".bss"
535 #endif
536
537 /* Get the address of a particular section or program header entry,
538 * accounting for the size of the entries.
539 */
540 /*
541 On PPC Reference Platform running Solaris 2.5.1
542 the plt section is also of type NOBI like the bss section.
543 (not really stored) and therefore sections after the bss
544 section start at the plt offset. The plt section is always
545 the one just before the bss section.
546 Thus, we modify the test from
547 if (NEW_SECTION_H (nn).sh_offset >= new_data2_offset)
548 to
549 if (NEW_SECTION_H (nn).sh_offset >=
550 OLD_SECTION_H (old_bss_index-1).sh_offset)
551 This is just a hack. We should put the new data section
552 before the .plt section.
553 And we should not have this routine at all but use
554 the libelf library to read the old file and create the new
555 file.
556 The changed code is minimal and depends on prep set in m/prep.h
557 Erik Deumens
558 Quantum Theory Project
559 University of Florida
560 deumens@qtp.ufl.edu
561 Apr 23, 1996
562 */
563
564 #define OLD_SECTION_H(n) \
565 (*(ElfW(Shdr) *) ((byte *) old_section_h + old_file_h->e_shentsize * (n)))
566 #define NEW_SECTION_H(n) \
567 (*(ElfW(Shdr) *) ((byte *) new_section_h + new_file_h->e_shentsize * (n)))
568 #define OLD_PROGRAM_H(n) \
569 (*(ElfW(Phdr) *) ((byte *) old_program_h + old_file_h->e_phentsize * (n)))
570 #define NEW_PROGRAM_H(n) \
571 (*(ElfW(Phdr) *) ((byte *) new_program_h + new_file_h->e_phentsize * (n)))
572
573 #define PATCH_INDEX(n) \
574 do { \
575 if ((int) (n) >= old_bss_index) \
576 (n)++; } while (0)
577 typedef unsigned char byte;
578
579 /* Round X up to a multiple of Y. */
580
581 static ElfW(Addr)
582 round_up (x, y)
583 ElfW(Addr) x, y;
584 {
585 int rem = x % y;
586 if (rem == 0)
587 return x;
588 return x - rem + y;
589 }
590
591 /* ****************************************************************
592 * unexec
593 *
594 * driving logic.
595 *
596 * In ELF, this works by replacing the old .bss section with a new
597 * .data section, and inserting an empty .bss immediately afterwards.
598 *
599 */
600 void
601 unexec (new_name, old_name, data_start, bss_start, entry_address)
602 char *new_name, *old_name;
603 unsigned data_start, bss_start, entry_address;
604 {
605 int new_file, old_file, new_file_size;
606
607 /* Pointers to the base of the image of the two files. */
608 caddr_t old_base, new_base;
609
610 /* Pointers to the file, program and section headers for the old and new
611 * files.
612 */
613 ElfW(Ehdr) *old_file_h, *new_file_h;
614 ElfW(Phdr) *old_program_h, *new_program_h;
615 ElfW(Shdr) *old_section_h, *new_section_h;
616
617 /* Point to the section name table in the old file */
618 char *old_section_names;
619
620 ElfW(Addr) old_bss_addr, new_bss_addr;
621 ElfW(Word) old_bss_size, new_data2_size;
622 ElfW(Off) new_data2_offset;
623 ElfW(Addr) new_data2_addr;
624
625 int n, nn, old_bss_index, old_data_index, new_data2_index;
626 int old_sbss_index, old_mdebug_index;
627 struct stat stat_buf;
628
629 /* Open the old file & map it into the address space. */
630
631 old_file = open (old_name, O_RDONLY);
632
633 if (old_file < 0)
634 fatal ("Can't open %s for reading: errno %d\n", old_name, errno);
635
636 if (fstat (old_file, &stat_buf) == -1)
637 fatal ("Can't fstat (%s): errno %d\n", old_name, errno);
638
639 old_base = mmap ((caddr_t) 0, stat_buf.st_size, PROT_READ, MAP_SHARED,
640 old_file, 0);
641
642 if (old_base == (caddr_t) -1)
643 fatal ("Can't mmap (%s): errno %d\n", old_name, errno);
644
645 #ifdef DEBUG
646 fprintf (stderr, "mmap (%s, %x) -> %x\n", old_name, stat_buf.st_size,
647 old_base);
648 #endif
649
650 /* Get pointers to headers & section names */
651
652 old_file_h = (ElfW(Ehdr) *) old_base;
653 old_program_h = (ElfW(Phdr) *) ((byte *) old_base + old_file_h->e_phoff);
654 old_section_h = (ElfW(Shdr) *) ((byte *) old_base + old_file_h->e_shoff);
655 old_section_names = (char *) old_base
656 + OLD_SECTION_H (old_file_h->e_shstrndx).sh_offset;
657
658 /* Find the old .bss section. Figure out parameters of the new
659 * data2 and bss sections.
660 */
661
662 for (old_bss_index = 1; old_bss_index < (int) old_file_h->e_shnum;
663 old_bss_index++)
664 {
665 #ifdef DEBUG
666 fprintf (stderr, "Looking for .bss - found %s\n",
667 old_section_names + OLD_SECTION_H (old_bss_index).sh_name);
668 #endif
669 if (!strcmp (old_section_names + OLD_SECTION_H (old_bss_index).sh_name,
670 ELF_BSS_SECTION_NAME))
671 break;
672 }
673 if (old_bss_index == old_file_h->e_shnum)
674 fatal ("Can't find .bss in %s.\n", old_name, 0);
675
676 for (old_sbss_index = 1; old_sbss_index < (int) old_file_h->e_shnum;
677 old_sbss_index++)
678 {
679 #ifdef DEBUG
680 fprintf (stderr, "Looking for .sbss - found %s\n",
681 old_section_names + OLD_SECTION_H (old_sbss_index).sh_name);
682 #endif
683 if (!strcmp (old_section_names + OLD_SECTION_H (old_sbss_index).sh_name,
684 ".sbss"))
685 break;
686 }
687 if (old_sbss_index == old_file_h->e_shnum)
688 {
689 old_sbss_index = -1;
690 old_bss_addr = OLD_SECTION_H(old_bss_index).sh_addr;
691 old_bss_size = OLD_SECTION_H(old_bss_index).sh_size;
692 new_data2_offset = OLD_SECTION_H(old_bss_index).sh_offset;
693 new_data2_index = old_bss_index;
694 }
695 else
696 {
697 old_bss_addr = OLD_SECTION_H(old_sbss_index).sh_addr;
698 old_bss_size = OLD_SECTION_H(old_bss_index).sh_size
699 + OLD_SECTION_H(old_sbss_index).sh_size;
700 new_data2_offset = OLD_SECTION_H(old_sbss_index).sh_offset;
701 new_data2_index = old_sbss_index;
702 }
703
704 for (old_mdebug_index = 1; old_mdebug_index < (int) old_file_h->e_shnum;
705 old_mdebug_index++)
706 {
707 #ifdef DEBUG
708 fprintf (stderr, "Looking for .mdebug - found %s\n",
709 old_section_names + OLD_SECTION_H (old_mdebug_index).sh_name);
710 #endif
711 if (!strcmp (old_section_names + OLD_SECTION_H (old_mdebug_index).sh_name,
712 ".mdebug"))
713 break;
714 }
715 if (old_mdebug_index == old_file_h->e_shnum)
716 old_mdebug_index = 0;
717
718 #if defined (emacs) || !defined (DEBUG)
719 new_bss_addr = (ElfW(Addr)) sbrk (0);
720 #else
721 new_bss_addr = old_bss_addr + old_bss_size + 0x1234;
722 #endif
723 new_data2_addr = old_bss_addr;
724 new_data2_size = new_bss_addr - old_bss_addr;
725
726 #ifdef DEBUG
727 fprintf (stderr, "old_bss_index %d\n", old_bss_index);
728 fprintf (stderr, "old_bss_addr %x\n", old_bss_addr);
729 fprintf (stderr, "old_bss_size %x\n", old_bss_size);
730 fprintf (stderr, "new_bss_addr %x\n", new_bss_addr);
731 fprintf (stderr, "new_data2_addr %x\n", new_data2_addr);
732 fprintf (stderr, "new_data2_size %x\n", new_data2_size);
733 fprintf (stderr, "new_data2_offset %x\n", new_data2_offset);
734 #endif
735
736 if ((unsigned) new_bss_addr < (unsigned) old_bss_addr + old_bss_size)
737 fatal (".bss shrank when undumping???\n", 0, 0);
738
739 /* Set the output file to the right size and mmap it. Set
740 * pointers to various interesting objects. stat_buf still has
741 * old_file data.
742 */
743
744 new_file = open (new_name, O_RDWR | O_CREAT, 0666);
745 if (new_file < 0)
746 fatal ("Can't creat (%s): errno %d\n", new_name, errno);
747
748 new_file_size = stat_buf.st_size + old_file_h->e_shentsize + new_data2_size;
749
750 if (ftruncate (new_file, new_file_size))
751 fatal ("Can't ftruncate (%s): errno %d\n", new_name, errno);
752
753 #ifdef UNEXEC_USE_MAP_PRIVATE
754 new_base = mmap ((caddr_t) 0, new_file_size, PROT_READ | PROT_WRITE,
755 MAP_PRIVATE, new_file, 0);
756 #else
757 new_base = mmap ((caddr_t) 0, new_file_size, PROT_READ | PROT_WRITE,
758 MAP_SHARED, new_file, 0);
759 #endif
760
761 if (new_base == (caddr_t) -1)
762 fatal ("Can't mmap (%s): errno %d\n", new_name, errno);
763
764 new_file_h = (ElfW(Ehdr) *) new_base;
765 new_program_h = (ElfW(Phdr) *) ((byte *) new_base + old_file_h->e_phoff);
766 new_section_h = (ElfW(Shdr) *)
767 ((byte *) new_base + old_file_h->e_shoff + new_data2_size);
768
769 /* Make our new file, program and section headers as copies of the
770 * originals.
771 */
772
773 memcpy (new_file_h, old_file_h, old_file_h->e_ehsize);
774 memcpy (new_program_h, old_program_h,
775 old_file_h->e_phnum * old_file_h->e_phentsize);
776
777 /* Modify the e_shstrndx if necessary. */
778 PATCH_INDEX (new_file_h->e_shstrndx);
779
780 /* Fix up file header. We'll add one section. Section header is
781 * further away now.
782 */
783
784 new_file_h->e_shoff += new_data2_size;
785 new_file_h->e_shnum += 1;
786
787 #ifdef DEBUG
788 fprintf (stderr, "Old section offset %x\n", old_file_h->e_shoff);
789 fprintf (stderr, "Old section count %d\n", old_file_h->e_shnum);
790 fprintf (stderr, "New section offset %x\n", new_file_h->e_shoff);
791 fprintf (stderr, "New section count %d\n", new_file_h->e_shnum);
792 #endif
793
794 /* Fix up a new program header. Extend the writable data segment so
795 * that the bss area is covered too. Find that segment by looking
796 * for a segment that ends just before the .bss area. Make sure
797 * that no segments are above the new .data2. Put a loop at the end
798 * to adjust the offset and address of any segment that is above
799 * data2, just in case we decide to allow this later.
800 */
801
802 for (n = new_file_h->e_phnum - 1; n >= 0; n--)
803 {
804 /* Compute maximum of all requirements for alignment of section. */
805 ElfW(Word) alignment = (NEW_PROGRAM_H (n)).p_align;
806 if ((OLD_SECTION_H (old_bss_index)).sh_addralign > alignment)
807 alignment = OLD_SECTION_H (old_bss_index).sh_addralign;
808
809 #ifdef __mips
810 /* According to r02kar@x4u2.desy.de (Karsten Kuenne)
811 and oliva@gnu.org (Alexandre Oliva), on IRIX 5.2, we
812 always get "Program segment above .bss" when dumping
813 when the executable doesn't have an sbss section. */
814 if (old_sbss_index != -1)
815 #endif /* __mips */
816 if (NEW_PROGRAM_H (n).p_vaddr + NEW_PROGRAM_H (n).p_filesz
817 > (old_sbss_index == -1
818 ? old_bss_addr
819 : round_up (old_bss_addr, alignment)))
820 fatal ("Program segment above .bss in %s\n", old_name, 0);
821
822 if (NEW_PROGRAM_H (n).p_type == PT_LOAD
823 && (round_up ((NEW_PROGRAM_H (n)).p_vaddr
824 + (NEW_PROGRAM_H (n)).p_filesz,
825 alignment)
826 == round_up (old_bss_addr, alignment)))
827 break;
828 }
829 if (n < 0)
830 fatal ("Couldn't find segment next to .bss in %s\n", old_name, 0);
831
832 /* Make sure that the size includes any padding before the old .bss
833 section. */
834 NEW_PROGRAM_H (n).p_filesz = new_bss_addr - NEW_PROGRAM_H (n).p_vaddr;
835 NEW_PROGRAM_H (n).p_memsz = NEW_PROGRAM_H (n).p_filesz;
836
837 #if 0 /* Maybe allow section after data2 - does this ever happen? */
838 for (n = new_file_h->e_phnum - 1; n >= 0; n--)
839 {
840 if (NEW_PROGRAM_H (n).p_vaddr
841 && NEW_PROGRAM_H (n).p_vaddr >= new_data2_addr)
842 NEW_PROGRAM_H (n).p_vaddr += new_data2_size - old_bss_size;
843
844 if (NEW_PROGRAM_H (n).p_offset >= new_data2_offset)
845 NEW_PROGRAM_H (n).p_offset += new_data2_size;
846 }
847 #endif
848
849 /* Fix up section headers based on new .data2 section. Any section
850 * whose offset or virtual address is after the new .data2 section
851 * gets its value adjusted. .bss size becomes zero and new address
852 * is set. data2 section header gets added by copying the existing
853 * .data header and modifying the offset, address and size.
854 */
855 for (old_data_index = 1; old_data_index < (int) old_file_h->e_shnum;
856 old_data_index++)
857 if (!strcmp (old_section_names + OLD_SECTION_H (old_data_index).sh_name,
858 ".data"))
859 break;
860 if (old_data_index == old_file_h->e_shnum)
861 fatal ("Can't find .data in %s.\n", old_name, 0);
862
863 /* Walk through all section headers, insert the new data2 section right
864 before the new bss section. */
865 for (n = 1, nn = 1; n < (int) old_file_h->e_shnum; n++, nn++)
866 {
867 caddr_t src;
868 /* If it is (s)bss section, insert the new data2 section before it. */
869 /* new_data2_index is the index of either old_sbss or old_bss, that was
870 chosen as a section for new_data2. */
871 if (n == new_data2_index)
872 {
873 /* Steal the data section header for this data2 section. */
874 memcpy (&NEW_SECTION_H (nn), &OLD_SECTION_H (old_data_index),
875 new_file_h->e_shentsize);
876
877 NEW_SECTION_H (nn).sh_addr = new_data2_addr;
878 NEW_SECTION_H (nn).sh_offset = new_data2_offset;
879 NEW_SECTION_H (nn).sh_size = new_data2_size;
880 /* Use the bss section's alignment. This will assure that the
881 new data2 section always be placed in the same spot as the old
882 bss section by any other application. */
883 NEW_SECTION_H (nn).sh_addralign = OLD_SECTION_H (n).sh_addralign;
884
885 /* Now copy over what we have in the memory now. */
886 memcpy (NEW_SECTION_H (nn).sh_offset + new_base,
887 (caddr_t) OLD_SECTION_H (n).sh_addr,
888 new_data2_size);
889 nn++;
890 }
891
892 memcpy (&NEW_SECTION_H (nn), &OLD_SECTION_H (n),
893 old_file_h->e_shentsize);
894
895 if (n == old_bss_index
896 /* The new bss and sbss section's size is zero, and its file offset
897 and virtual address should be off by NEW_DATA2_SIZE. */
898 || n == old_sbss_index
899 )
900 {
901 /* NN should be `old_s?bss_index + 1' at this point. */
902 NEW_SECTION_H (nn).sh_offset =
903 NEW_SECTION_H (new_data2_index).sh_offset + new_data2_size;
904 NEW_SECTION_H (nn).sh_addr =
905 NEW_SECTION_H (new_data2_index).sh_addr + new_data2_size;
906 /* Let the new bss section address alignment be the same as the
907 section address alignment followed the old bss section, so
908 this section will be placed in exactly the same place. */
909 NEW_SECTION_H (nn).sh_addralign = OLD_SECTION_H (nn).sh_addralign;
910 NEW_SECTION_H (nn).sh_size = 0;
911 }
912 else
913 {
914 /* Any section that was original placed AFTER the bss
915 section should now be off by NEW_DATA2_SIZE. */
916 #ifdef SOLARIS_POWERPC
917 /* On PPC Reference Platform running Solaris 2.5.1
918 the plt section is also of type NOBI like the bss section.
919 (not really stored) and therefore sections after the bss
920 section start at the plt offset. The plt section is always
921 the one just before the bss section.
922 It would be better to put the new data section before
923 the .plt section, or use libelf instead.
924 Erik Deumens, deumens@qtp.ufl.edu. */
925 if (NEW_SECTION_H (nn).sh_offset
926 >= OLD_SECTION_H (old_bss_index-1).sh_offset)
927 NEW_SECTION_H (nn).sh_offset += new_data2_size;
928 #else
929 if (round_up (NEW_SECTION_H (nn).sh_offset,
930 OLD_SECTION_H (old_bss_index).sh_addralign)
931 >= new_data2_offset)
932 NEW_SECTION_H (nn).sh_offset += new_data2_size;
933 #endif
934 /* Any section that was originally placed after the section
935 header table should now be off by the size of one section
936 header table entry. */
937 if (NEW_SECTION_H (nn).sh_offset > new_file_h->e_shoff)
938 NEW_SECTION_H (nn).sh_offset += new_file_h->e_shentsize;
939 }
940
941 /* If any section hdr refers to the section after the new .data
942 section, make it refer to next one because we have inserted
943 a new section in between. */
944
945 PATCH_INDEX (NEW_SECTION_H (nn).sh_link);
946 /* For symbol tables, info is a symbol table index,
947 so don't change it. */
948 if (NEW_SECTION_H (nn).sh_type != SHT_SYMTAB
949 && NEW_SECTION_H (nn).sh_type != SHT_DYNSYM)
950 PATCH_INDEX (NEW_SECTION_H (nn).sh_info);
951
952 /* Now, start to copy the content of sections. */
953 if (NEW_SECTION_H (nn).sh_type == SHT_NULL
954 || NEW_SECTION_H (nn).sh_type == SHT_NOBITS)
955 continue;
956
957 /* Write out the sections. .data and .data1 (and data2, called
958 ".data" in the strings table) get copied from the current process
959 instead of the old file. */
960 if (!strcmp (old_section_names + NEW_SECTION_H (n).sh_name, ".data")
961 || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name),
962 ".sdata")
963 || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name),
964 ".lit4")
965 || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name),
966 ".lit8")
967 || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name),
968 ".got")
969 || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name),
970 ".sdata1")
971 || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name),
972 ".data1"))
973 src = (caddr_t) OLD_SECTION_H (n).sh_addr;
974 else
975 src = old_base + OLD_SECTION_H (n).sh_offset;
976
977 memcpy (NEW_SECTION_H (nn).sh_offset + new_base, src,
978 NEW_SECTION_H (nn).sh_size);
979
980 #ifdef __alpha__
981 /* Update Alpha COFF symbol table: */
982 if (strcmp (old_section_names + OLD_SECTION_H (n).sh_name, ".mdebug")
983 == 0)
984 {
985 pHDRR symhdr = (pHDRR) (NEW_SECTION_H (nn).sh_offset + new_base);
986
987 symhdr->cbLineOffset += new_data2_size;
988 symhdr->cbDnOffset += new_data2_size;
989 symhdr->cbPdOffset += new_data2_size;
990 symhdr->cbSymOffset += new_data2_size;
991 symhdr->cbOptOffset += new_data2_size;
992 symhdr->cbAuxOffset += new_data2_size;
993 symhdr->cbSsOffset += new_data2_size;
994 symhdr->cbSsExtOffset += new_data2_size;
995 symhdr->cbFdOffset += new_data2_size;
996 symhdr->cbRfdOffset += new_data2_size;
997 symhdr->cbExtOffset += new_data2_size;
998 }
999 #endif /* __alpha__ */
1000
1001 #if defined (__sony_news) && defined (_SYSTYPE_SYSV)
1002 if (NEW_SECTION_H (nn).sh_type == SHT_MIPS_DEBUG && old_mdebug_index)
1003 {
1004 int diff = NEW_SECTION_H(nn).sh_offset
1005 - OLD_SECTION_H(old_mdebug_index).sh_offset;
1006 HDRR *phdr = (HDRR *)(NEW_SECTION_H (nn).sh_offset + new_base);
1007
1008 if (diff)
1009 {
1010 phdr->cbLineOffset += diff;
1011 phdr->cbDnOffset += diff;
1012 phdr->cbPdOffset += diff;
1013 phdr->cbSymOffset += diff;
1014 phdr->cbOptOffset += diff;
1015 phdr->cbAuxOffset += diff;
1016 phdr->cbSsOffset += diff;
1017 phdr->cbSsExtOffset += diff;
1018 phdr->cbFdOffset += diff;
1019 phdr->cbRfdOffset += diff;
1020 phdr->cbExtOffset += diff;
1021 }
1022 }
1023 #endif /* __sony_news && _SYSTYPE_SYSV */
1024
1025 #if __sgi
1026 /* Adjust the HDRR offsets in .mdebug and copy the
1027 line data if it's in its usual 'hole' in the object.
1028 Makes the new file debuggable with dbx.
1029 patches up two problems: the absolute file offsets
1030 in the HDRR record of .mdebug (see /usr/include/syms.h), and
1031 the ld bug that gets the line table in a hole in the
1032 elf file rather than in the .mdebug section proper.
1033 David Anderson. davea@sgi.com Jan 16,1994. */
1034 if (n == old_mdebug_index)
1035 {
1036 #define MDEBUGADJUST(__ct,__fileaddr) \
1037 if (n_phdrr->__ct > 0) \
1038 { \
1039 n_phdrr->__fileaddr += movement; \
1040 }
1041
1042 HDRR * o_phdrr = (HDRR *)((byte *)old_base + OLD_SECTION_H (n).sh_offset);
1043 HDRR * n_phdrr = (HDRR *)((byte *)new_base + NEW_SECTION_H (nn).sh_offset);
1044 unsigned movement = new_data2_size;
1045
1046 MDEBUGADJUST (idnMax, cbDnOffset);
1047 MDEBUGADJUST (ipdMax, cbPdOffset);
1048 MDEBUGADJUST (isymMax, cbSymOffset);
1049 MDEBUGADJUST (ioptMax, cbOptOffset);
1050 MDEBUGADJUST (iauxMax, cbAuxOffset);
1051 MDEBUGADJUST (issMax, cbSsOffset);
1052 MDEBUGADJUST (issExtMax, cbSsExtOffset);
1053 MDEBUGADJUST (ifdMax, cbFdOffset);
1054 MDEBUGADJUST (crfd, cbRfdOffset);
1055 MDEBUGADJUST (iextMax, cbExtOffset);
1056 /* The Line Section, being possible off in a hole of the object,
1057 requires special handling. */
1058 if (n_phdrr->cbLine > 0)
1059 {
1060 if (o_phdrr->cbLineOffset > (OLD_SECTION_H (n).sh_offset
1061 + OLD_SECTION_H (n).sh_size))
1062 {
1063 /* line data is in a hole in elf. do special copy and adjust
1064 for this ld mistake.
1065 */
1066 n_phdrr->cbLineOffset += movement;
1067
1068 memcpy (n_phdrr->cbLineOffset + new_base,
1069 o_phdrr->cbLineOffset + old_base, n_phdrr->cbLine);
1070 }
1071 else
1072 {
1073 /* somehow line data is in .mdebug as it is supposed to be. */
1074 MDEBUGADJUST (cbLine, cbLineOffset);
1075 }
1076 }
1077 }
1078 #endif /* __sgi */
1079
1080 /* If it is the symbol table, its st_shndx field needs to be patched. */
1081 if (NEW_SECTION_H (nn).sh_type == SHT_SYMTAB
1082 || NEW_SECTION_H (nn).sh_type == SHT_DYNSYM)
1083 {
1084 ElfW(Shdr) *spt = &NEW_SECTION_H (nn);
1085 unsigned int num = spt->sh_size / spt->sh_entsize;
1086 ElfW(Sym) * sym = (ElfW(Sym) *) (NEW_SECTION_H (nn).sh_offset +
1087 new_base);
1088 for (; num--; sym++)
1089 {
1090 if ((sym->st_shndx == SHN_UNDEF)
1091 || (sym->st_shndx == SHN_ABS)
1092 || (sym->st_shndx == SHN_COMMON))
1093 continue;
1094
1095 PATCH_INDEX (sym->st_shndx);
1096 }
1097 }
1098 }
1099
1100 /* Update the symbol values of _edata and _end. */
1101 for (n = new_file_h->e_shnum - 1; n; n--)
1102 {
1103 byte *symnames;
1104 ElfW(Sym) *symp, *symendp;
1105
1106 if (NEW_SECTION_H (n).sh_type != SHT_DYNSYM
1107 && NEW_SECTION_H (n).sh_type != SHT_SYMTAB)
1108 continue;
1109
1110 symnames = ((byte *) new_base
1111 + NEW_SECTION_H (NEW_SECTION_H (n).sh_link).sh_offset);
1112 symp = (ElfW(Sym) *) (NEW_SECTION_H (n).sh_offset + new_base);
1113 symendp = (ElfW(Sym) *) ((byte *)symp + NEW_SECTION_H (n).sh_size);
1114
1115 for (; symp < symendp; symp ++)
1116 if (strcmp ((char *) (symnames + symp->st_name), "_end") == 0
1117 || strcmp ((char *) (symnames + symp->st_name), "end") == 0
1118 || strcmp ((char *) (symnames + symp->st_name), "_edata") == 0
1119 || strcmp ((char *) (symnames + symp->st_name), "edata") == 0)
1120 memcpy (&symp->st_value, &new_bss_addr, sizeof (new_bss_addr));
1121 }
1122
1123 /* This loop seeks out relocation sections for the data section, so
1124 that it can undo relocations performed by the runtime linker. */
1125 for (n = new_file_h->e_shnum - 1; n; n--)
1126 {
1127 ElfW(Shdr) section = NEW_SECTION_H (n);
1128 switch (section.sh_type) {
1129 default:
1130 break;
1131 case SHT_REL:
1132 case SHT_RELA:
1133 /* This code handles two different size structs, but there should
1134 be no harm in that provided that r_offset is always the first
1135 member. */
1136 nn = section.sh_info;
1137 if (!strcmp (old_section_names + NEW_SECTION_H (nn).sh_name, ".data")
1138 || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name),
1139 ".sdata")
1140 || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name),
1141 ".lit4")
1142 || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name),
1143 ".lit8")
1144 || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name),
1145 ".got")
1146 || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name),
1147 ".sdata1")
1148 || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name),
1149 ".data1"))
1150 {
1151 ElfW(Addr) offset = NEW_SECTION_H (nn).sh_addr -
1152 NEW_SECTION_H (nn).sh_offset;
1153 caddr_t reloc = old_base + section.sh_offset, end;
1154 for (end = reloc + section.sh_size; reloc < end;
1155 reloc += section.sh_entsize)
1156 {
1157 ElfW(Addr) addr = ((ElfW(Rel) *) reloc)->r_offset - offset;
1158 #ifdef __alpha__
1159 /* The Alpha ELF binutils currently have a bug that
1160 sometimes results in relocs that contain all
1161 zeroes. Work around this for now... */
1162 if (((ElfW(Rel) *) reloc)->r_offset == 0)
1163 continue;
1164 #endif
1165 memcpy (new_base + addr, old_base + addr, sizeof(ElfW(Addr)));
1166 }
1167 }
1168 break;
1169 }
1170 }
1171
1172 #ifdef UNEXEC_USE_MAP_PRIVATE
1173 if (lseek (new_file, 0, SEEK_SET) == -1)
1174 fatal ("Can't rewind (%s): errno %d\n", new_name, errno);
1175
1176 if (write (new_file, new_base, new_file_size) != new_file_size)
1177 fatal ("Can't write (%s): errno %d\n", new_name, errno);
1178 #endif
1179
1180 /* Close the files and make the new file executable. */
1181
1182 if (close (old_file))
1183 fatal ("Can't close (%s): errno %d\n", old_name, errno);
1184
1185 if (close (new_file))
1186 fatal ("Can't close (%s): errno %d\n", new_name, errno);
1187
1188 if (stat (new_name, &stat_buf) == -1)
1189 fatal ("Can't stat (%s): errno %d\n", new_name, errno);
1190
1191 n = umask (777);
1192 umask (n);
1193 stat_buf.st_mode |= 0111 & ~n;
1194 if (chmod (new_name, stat_buf.st_mode) == -1)
1195 fatal ("Can't chmod (%s): errno %d\n", new_name, errno);
1196 }
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