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(compilation-handle-exit): If process-status doesn't
[bpt/emacs.git] / src / unexelf.c
CommitLineData
e40c4104
RS		 1/* Copyright (C) 1985, 1986, 1987, 1988, 1990, 1992
2 Free Software Foundation, Inc.
d427b66a 3
3b7ad313 4This file is part of GNU Emacs.
e40c4104 5
3b7ad313
EN		 6GNU Emacs is free software; you can redistribute it and/or modify
7it under the terms of the GNU General Public License as published by
8the Free Software Foundation; either version 2, or (at your option)
9any later version.
e40c4104 10
3b7ad313
EN		 11GNU Emacs is distributed in the hope that it will be useful,
12but WITHOUT ANY WARRANTY; without even the implied warranty of
13MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14GNU General Public License for more details.
15
16You should have received a copy of the GNU General Public License
17along with GNU Emacs; see the file COPYING. If not, write to
18the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19Boston, MA 02111-1307, USA.
d427b66a
JB		 20
21In other words, you are welcome to use, share and improve this program.
22You are forbidden to forbid anyone else to use, share and improve
23what 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, a_name, data_start, bss_start, entry_address)
37 * char *new_name, *a_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 a_name is non-NULL, the symbol table will be taken from the given file.
43 * On some machines, an existing a_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
95raid:/nfs/raid/src/dist-18.56/src> dump -h temacs
96
97temacs:
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
163raid:/nfs/raid/src/dist-18.56/src> dump -h xemacs
164
165xemacs:
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
243raid:/nfs/raid/src/dist-18.56/src> dump -f temacs
244
245temacs:
246
247 **** ELF HEADER ****
248Class Data Type Machine Version
249Entry Phoff Shoff Flags Ehsize
250Phentsize Phnum Shentsz Shnum Shstrndx
251
2521 1 2 3 1
2530x80499cc 0x34 0x792f4 0 0x34
2540x20 5 0x28 21 19
255
256raid:/nfs/raid/src/dist-18.56/src> dump -f xemacs
257
258xemacs:
259
260 **** ELF HEADER ****
261Class Data Type Machine Version
262Entry Phoff Shoff Flags Ehsize
263Phentsize Phnum Shentsz Shnum Shstrndx
264
2651 1 2 3 1
2660x80499cc 0x34 0x96200 0 0x34
2670x20 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
275raid:/nfs/raid/src/dist-18.56/src> dump -o temacs
276
277temacs:
278 ***** PROGRAM EXECUTION HEADER *****
279Type Offset Vaddr Paddr
280Filesz Memsz Flags Align
281
2826 0x34 0x8048034 0
2830xa0 0xa0 5 0
284
2853 0xd4 0 0
2860x13 0 4 0
287
2881 0x34 0x8048034 0
2890x3f2f9 0x3f2f9 5 0x1000
290
2911 0x3f330 0x8088330 0
2920x215c4 0x25a60 7 0x1000
293
2942 0x60874 0x80a9874 0
2950x80 0 7 0
296
297raid:/nfs/raid/src/dist-18.56/src> dump -o xemacs
298
299xemacs:
300 ***** PROGRAM EXECUTION HEADER *****
301Type Offset Vaddr Paddr
302Filesz Memsz Flags Align
303
3046 0x34 0x8048034 0
3050xa0 0xa0 5 0
306
3073 0xd4 0 0
3080x13 0 4 0
309
3101 0x34 0x8048034 0
3110x3f2f9 0x3f2f9 5 0x1000
312
3131 0x3f330 0x8088330 0
3140x3e4d0 0x3e4d0 7 0x1000
315
3162 0x60874 0x80a9874 0
3170x80 0 7 0
318
319
320 */
e40c4104
RS		 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
d427b66a 352
e40c4104
RS		 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
d427b66a
JB		 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#include <elf.h>
424#include <sys/mman.h>
425
426#ifndef emacs
d7cb42c3 427#define fatal(a, b, c) fprintf (stderr, a, b, c), exit (1)
d427b66a 428#else
92b52293 429#include "config.h"
d7cb42c3 430extern void fatal (char *, ...);
d427b66a
JB		 431#endif
432
d8858cfe
RS		 433#ifndef ELF_BSS_SECTION_NAME
434#define ELF_BSS_SECTION_NAME ".bss"
435#endif
436
d427b66a
JB		 437/* Get the address of a particular section or program header entry,
438 * accounting for the size of the entries.
439 */
440
441#define OLD_SECTION_H(n) \
442 (*(Elf32_Shdr *) ((byte *) old_section_h + old_file_h->e_shentsize * (n)))
443#define NEW_SECTION_H(n) \
444 (*(Elf32_Shdr *) ((byte *) new_section_h + new_file_h->e_shentsize * (n)))
445#define OLD_PROGRAM_H(n) \
446 (*(Elf32_Phdr *) ((byte *) old_program_h + old_file_h->e_phentsize * (n)))
447#define NEW_PROGRAM_H(n) \
448 (*(Elf32_Phdr *) ((byte *) new_program_h + new_file_h->e_phentsize * (n)))
449
e40c4104
RS		 450#define PATCH_INDEX(n) \
451 do { \
d7cb42c3 452 if ((int) (n) >= old_bss_index) \
e40c4104 453 (n)++; } while (0)
d427b66a
JB		 454typedef unsigned char byte;
455
e40c4104
RS		 456/* Round X up to a multiple of Y. */
457
458int
459round_up (x, y)
460 int x, y;
461{
462 int rem = x % y;
463 if (rem == 0)
464 return x;
465 return x - rem + y;
466}
467
d427b66a
JB		 468/* ****************************************************************
469 * unexec
470 *
471 * driving logic.
472 *
473 * In ELF, this works by replacing the old .bss section with a new
474 * .data section, and inserting an empty .bss immediately afterwards.
475 *
476 */
477void
478unexec (new_name, old_name, data_start, bss_start, entry_address)
479 char *new_name, *old_name;
480 unsigned data_start, bss_start, entry_address;
481{
d427b66a
JB		 482 int new_file, old_file, new_file_size;
483
484 /* Pointers to the base of the image of the two files. */
485 caddr_t old_base, new_base;
486
487 /* Pointers to the file, program and section headers for the old and new
488 * files.
489 */
490 Elf32_Ehdr *old_file_h, *new_file_h;
491 Elf32_Phdr *old_program_h, *new_program_h;
492 Elf32_Shdr *old_section_h, *new_section_h;
493
494 /* Point to the section name table in the old file */
495 char *old_section_names;
496
497 Elf32_Addr old_bss_addr, new_bss_addr;
498 Elf32_Word old_bss_size, new_data2_size;
499 Elf32_Off new_data2_offset;
500 Elf32_Addr new_data2_addr;
501
e40c4104 502 int n, nn, old_bss_index, old_data_index, new_data2_index;
d427b66a
JB		 503 struct stat stat_buf;
504
505 /* Open the old file & map it into the address space. */
506
507 old_file = open (old_name, O_RDONLY);
508
509 if (old_file < 0)
510 fatal ("Can't open %s for reading: errno %d\n", old_name, errno);
511
512 if (fstat (old_file, &stat_buf) == -1)
d7cb42c3 513 fatal ("Can't fstat (%s): errno %d\n", old_name, errno);
d427b66a
JB		 514
515 old_base = mmap (0, stat_buf.st_size, PROT_READ, MAP_SHARED, old_file, 0);
516
517 if (old_base == (caddr_t) -1)
d7cb42c3 518 fatal ("Can't mmap (%s): errno %d\n", old_name, errno);
d427b66a
JB		 519
520#ifdef DEBUG
d7cb42c3 521 fprintf (stderr, "mmap (%s, %x) -> %x\n", old_name, stat_buf.st_size,
d427b66a
JB		 522 old_base);
523#endif
524
525 /* Get pointers to headers & section names */
526
527 old_file_h = (Elf32_Ehdr *) old_base;
528 old_program_h = (Elf32_Phdr *) ((byte *) old_base + old_file_h->e_phoff);
529 old_section_h = (Elf32_Shdr *) ((byte *) old_base + old_file_h->e_shoff);
530 old_section_names = (char *) old_base
d7cb42c3 531 + OLD_SECTION_H (old_file_h->e_shstrndx).sh_offset;
d427b66a
JB		 532
533 /* Find the old .bss section. Figure out parameters of the new
534 * data2 and bss sections.
535 */
536
d7cb42c3
RS		 537 for (old_bss_index = 1; old_bss_index < (int) old_file_h->e_shnum;
538 old_bss_index++)
d427b66a
JB		 539 {
540#ifdef DEBUG
541 fprintf (stderr, "Looking for .bss - found %s\n",
d7cb42c3 542 old_section_names + OLD_SECTION_H (old_bss_index).sh_name);
d427b66a 543#endif
d7cb42c3 544 if (!strcmp (old_section_names + OLD_SECTION_H (old_bss_index).sh_name,
d8858cfe 545 ELF_BSS_SECTION_NAME))
d427b66a
JB		 546 break;
547 }
548 if (old_bss_index == old_file_h->e_shnum)
549 fatal ("Can't find .bss in %s.\n", old_name, 0);
550
d7cb42c3
RS		 551 old_bss_addr = OLD_SECTION_H (old_bss_index).sh_addr;
552 old_bss_size = OLD_SECTION_H (old_bss_index).sh_size;
d427b66a 553#if defined(emacs) || !defined(DEBUG)
8bf761ce 554 new_bss_addr = (Elf32_Addr) sbrk (0);
d427b66a
JB		 555#else
556 new_bss_addr = old_bss_addr + old_bss_size + 0x1234;
557#endif
558 new_data2_addr = old_bss_addr;
559 new_data2_size = new_bss_addr - old_bss_addr;
d7cb42c3 560 new_data2_offset = OLD_SECTION_H (old_bss_index).sh_offset;
d427b66a
JB		 561
562#ifdef DEBUG
563 fprintf (stderr, "old_bss_index %d\n", old_bss_index);
564 fprintf (stderr, "old_bss_addr %x\n", old_bss_addr);
565 fprintf (stderr, "old_bss_size %x\n", old_bss_size);
566 fprintf (stderr, "new_bss_addr %x\n", new_bss_addr);
567 fprintf (stderr, "new_data2_addr %x\n", new_data2_addr);
568 fprintf (stderr, "new_data2_size %x\n", new_data2_size);
569 fprintf (stderr, "new_data2_offset %x\n", new_data2_offset);
570#endif
571
572 if ((unsigned) new_bss_addr < (unsigned) old_bss_addr + old_bss_size)
573 fatal (".bss shrank when undumping???\n", 0, 0);
574
d7cb42c3 575 /* Set the output file to the right size and mmap it. Set
d427b66a
JB		 576 * pointers to various interesting objects. stat_buf still has
577 * old_file data.
578 */
579
580 new_file = open (new_name, O_RDWR | O_CREAT, 0666);
581 if (new_file < 0)
d7cb42c3 582 fatal ("Can't creat (%s): errno %d\n", new_name, errno);
d427b66a
JB		 583
584 new_file_size = stat_buf.st_size + old_file_h->e_shentsize + new_data2_size;
585
586 if (ftruncate (new_file, new_file_size))
d7cb42c3 587 fatal ("Can't ftruncate (%s): errno %d\n", new_name, errno);
d427b66a 588
04f903c0
KH		 589#ifdef UNEXEC_USE_MAP_PRIVATE
590 new_base = mmap (0, new_file_size, PROT_READ | PROT_WRITE, MAP_PRIVATE,
591 new_file, 0);
592#else
d427b66a
JB		 593 new_base = mmap (0, new_file_size, PROT_READ | PROT_WRITE, MAP_SHARED,
594 new_file, 0);
04f903c0 595#endif
d427b66a
JB		 596
597 if (new_base == (caddr_t) -1)
d7cb42c3 598 fatal ("Can't mmap (%s): errno %d\n", new_name, errno);
d427b66a
JB		 599
600 new_file_h = (Elf32_Ehdr *) new_base;
601 new_program_h = (Elf32_Phdr *) ((byte *) new_base + old_file_h->e_phoff);
602 new_section_h = (Elf32_Shdr *)
603 ((byte *) new_base + old_file_h->e_shoff + new_data2_size);
604
605 /* Make our new file, program and section headers as copies of the
606 * originals.
607 */
608
609 memcpy (new_file_h, old_file_h, old_file_h->e_ehsize);
610 memcpy (new_program_h, old_program_h,
611 old_file_h->e_phnum * old_file_h->e_phentsize);
e40c4104
RS		 612
613 /* Modify the e_shstrndx if necessary. */
614 PATCH_INDEX (new_file_h->e_shstrndx);
d427b66a
JB		 615
616 /* Fix up file header. We'll add one section. Section header is
617 * further away now.
618 */
619
620 new_file_h->e_shoff += new_data2_size;
621 new_file_h->e_shnum += 1;
622
623#ifdef DEBUG
624 fprintf (stderr, "Old section offset %x\n", old_file_h->e_shoff);
625 fprintf (stderr, "Old section count %d\n", old_file_h->e_shnum);
626 fprintf (stderr, "New section offset %x\n", new_file_h->e_shoff);
627 fprintf (stderr, "New section count %d\n", new_file_h->e_shnum);
628#endif
629
630 /* Fix up a new program header. Extend the writable data segment so
631 * that the bss area is covered too. Find that segment by looking
632 * for a segment that ends just before the .bss area. Make sure
633 * that no segments are above the new .data2. Put a loop at the end
634 * to adjust the offset and address of any segment that is above
635 * data2, just in case we decide to allow this later.
636 */
637
638 for (n = new_file_h->e_phnum - 1; n >= 0; n--)
639 {
e40c4104
RS		 640 /* Compute maximum of all requirements for alignment of section. */
641 int alignment = (NEW_PROGRAM_H (n)).p_align;
642 if ((OLD_SECTION_H (old_bss_index)).sh_addralign > alignment)
643 alignment = OLD_SECTION_H (old_bss_index).sh_addralign;
644
d7cb42c3 645 if (NEW_PROGRAM_H (n).p_vaddr + NEW_PROGRAM_H (n).p_filesz > old_bss_addr)
d427b66a
JB		 646 fatal ("Program segment above .bss in %s\n", old_name, 0);
647
d7cb42c3 648 if (NEW_PROGRAM_H (n).p_type == PT_LOAD
e40c4104
RS		 649 && (round_up ((NEW_PROGRAM_H (n)).p_vaddr
650 + (NEW_PROGRAM_H (n)).p_filesz,
651 alignment)
652 == round_up (old_bss_addr, alignment)))
d427b66a
JB		 653 break;
654 }
655 if (n < 0)
656 fatal ("Couldn't find segment next to .bss in %s\n", old_name, 0);
657
d7cb42c3
RS		 658 NEW_PROGRAM_H (n).p_filesz += new_data2_size;
659 NEW_PROGRAM_H (n).p_memsz = NEW_PROGRAM_H (n).p_filesz;
d427b66a
JB		 660
661#if 0 /* Maybe allow section after data2 - does this ever happen? */
662 for (n = new_file_h->e_phnum - 1; n >= 0; n--)
663 {
d7cb42c3
RS		 664 if (NEW_PROGRAM_H (n).p_vaddr
665 && NEW_PROGRAM_H (n).p_vaddr >= new_data2_addr)
666 NEW_PROGRAM_H (n).p_vaddr += new_data2_size - old_bss_size;
d427b66a 667
d7cb42c3
RS		 668 if (NEW_PROGRAM_H (n).p_offset >= new_data2_offset)
669 NEW_PROGRAM_H (n).p_offset += new_data2_size;
d427b66a
JB		 670 }
671#endif
672
673 /* Fix up section headers based on new .data2 section. Any section
674 * whose offset or virtual address is after the new .data2 section
675 * gets its value adjusted. .bss size becomes zero and new address
676 * is set. data2 section header gets added by copying the existing
677 * .data header and modifying the offset, address and size.
678 */
d7cb42c3 679 for (old_data_index = 1; old_data_index < (int) old_file_h->e_shnum;
d427b66a 680 old_data_index++)
d7cb42c3 681 if (!strcmp (old_section_names + OLD_SECTION_H (old_data_index).sh_name,
d427b66a
JB		 682 ".data"))
683 break;
684 if (old_data_index == old_file_h->e_shnum)
685 fatal ("Can't find .data in %s.\n", old_name, 0);
686
e40c4104
RS		 687 /* Walk through all section headers, insert the new data2 section right
688 before the new bss section. */
d7cb42c3 689 for (n = 1, nn = 1; n < (int) old_file_h->e_shnum; n++, nn++)
d427b66a
JB		 690 {
691 caddr_t src;
e40c4104
RS		 692 /* If it is bss section, insert the new data2 section before it. */
693 if (n == old_bss_index)
694 {
695 /* Steal the data section header for this data2 section. */
d7cb42c3 696 memcpy (&NEW_SECTION_H (nn), &OLD_SECTION_H (old_data_index),
e40c4104
RS		 697 new_file_h->e_shentsize);
698
d7cb42c3
RS		 699 NEW_SECTION_H (nn).sh_addr = new_data2_addr;
700 NEW_SECTION_H (nn).sh_offset = new_data2_offset;
701 NEW_SECTION_H (nn).sh_size = new_data2_size;
e40c4104
RS		 702 /* Use the bss section's alignment. This will assure that the
703 new data2 section always be placed in the same spot as the old
704 bss section by any other application. */
d7cb42c3 705 NEW_SECTION_H (nn).sh_addralign = OLD_SECTION_H (n).sh_addralign;
e40c4104
RS		 706
707 /* Now copy over what we have in the memory now. */
d7cb42c3
RS		 708 memcpy (NEW_SECTION_H (nn).sh_offset + new_base,
709 (caddr_t) OLD_SECTION_H (n).sh_addr,
e40c4104
RS		 710 new_data2_size);
711 nn++;
712 }
713
d7cb42c3 714 memcpy (&NEW_SECTION_H (nn), &OLD_SECTION_H (n),
e40c4104
RS		 715 old_file_h->e_shentsize);
716
717 /* The new bss section's size is zero, and its file offset and virtual
718 address should be off by NEW_DATA2_SIZE. */
719 if (n == old_bss_index)
720 {
721 /* NN should be `old_bss_index + 1' at this point. */
d7cb42c3
RS		 722 NEW_SECTION_H (nn).sh_offset += new_data2_size;
723 NEW_SECTION_H (nn).sh_addr += new_data2_size;
e40c4104
RS		 724 /* Let the new bss section address alignment be the same as the
725 section address alignment followed the old bss section, so
726 this section will be placed in exactly the same place. */
d7cb42c3
RS		 727 NEW_SECTION_H (nn).sh_addralign = OLD_SECTION_H (nn).sh_addralign;
728 NEW_SECTION_H (nn).sh_size = 0;
e40c4104 729 }
85b2e0ee
RS		 730 else
731 {
732 /* Any section that was original placed AFTER the bss
733 section should now be off by NEW_DATA2_SIZE. */
734 if (NEW_SECTION_H (nn).sh_offset >= new_data2_offset)
735 NEW_SECTION_H (nn).sh_offset += new_data2_size;
736 /* Any section that was originally placed after the section
737 header table should now be off by the size of one section
738 header table entry. */
739 if (NEW_SECTION_H (nn).sh_offset > new_file_h->e_shoff)
740 NEW_SECTION_H (nn).sh_offset += new_file_h->e_shentsize;
741 }
742
e40c4104
RS		 743 /* If any section hdr refers to the section after the new .data
744 section, make it refer to next one because we have inserted
8917361f 745 a new section in between. */
e40c4104 746
d7cb42c3 747 PATCH_INDEX (NEW_SECTION_H (nn).sh_link);
8917361f
RS		 748 /* For symbol tables, info is a symbol table index,
749 so don't change it. */
750 if (NEW_SECTION_H (nn).sh_type != SHT_SYMTAB
751 && NEW_SECTION_H (nn).sh_type != SHT_DYNSYM)
752 PATCH_INDEX (NEW_SECTION_H (nn).sh_info);
753
754 /* Now, start to copy the content of sections. */
d7cb42c3
RS		 755 if (NEW_SECTION_H (nn).sh_type == SHT_NULL
756 || NEW_SECTION_H (nn).sh_type == SHT_NOBITS)
d427b66a 757 continue;
e40c4104
RS		 758
759 /* Write out the sections. .data and .data1 (and data2, called
8917361f
RS		 760 ".data" in the strings table) get copied from the current process
761 instead of the old file. */
d7cb42c3
RS		 762 if (!strcmp (old_section_names + NEW_SECTION_H (n).sh_name, ".data")
763 || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name),
d427b66a 764 ".data1"))
d7cb42c3 765 src = (caddr_t) OLD_SECTION_H (n).sh_addr;
d427b66a 766 else
d7cb42c3 767 src = old_base + OLD_SECTION_H (n).sh_offset;
e40c4104 768
d7cb42c3
RS		 769 memcpy (NEW_SECTION_H (nn).sh_offset + new_base, src,
770 NEW_SECTION_H (nn).sh_size);
e40c4104 771
8917361f 772 /* If it is the symbol table, its st_shndx field needs to be patched. */
d7cb42c3
RS		 773 if (NEW_SECTION_H (nn).sh_type == SHT_SYMTAB
774 || NEW_SECTION_H (nn).sh_type == SHT_DYNSYM)
e40c4104 775 {
d7cb42c3 776 Elf32_Shdr *spt = &NEW_SECTION_H (nn);
e40c4104 777 unsigned int num = spt->sh_size / spt->sh_entsize;
d7cb42c3 778 Elf32_Sym * sym = (Elf32_Sym *) (NEW_SECTION_H (nn).sh_offset +
e40c4104
RS		 779 new_base);
780 for (; num--; sym++)
781 {
782 if ((sym->st_shndx == SHN_UNDEF)
783 || (sym->st_shndx == SHN_ABS)
784 || (sym->st_shndx == SHN_COMMON))
785 continue;
786
d7cb42c3 787 PATCH_INDEX (sym->st_shndx);
e40c4104
RS		 788 }
789 }
d427b66a
JB		 790 }
791
8917361f 792 /* Update the symbol values of _edata and _end. */
8bf761ce
RS		 793 for (n = new_file_h->e_shnum - 1; n; n--)
794 {
795 byte *symnames;
796 Elf32_Sym *symp, *symendp;
797
798 if (NEW_SECTION_H (n).sh_type != SHT_DYNSYM
799 && NEW_SECTION_H (n).sh_type != SHT_SYMTAB)
800 continue;
801
8c1e9afe
KH		 802 symnames = ((byte *) new_base
803 + NEW_SECTION_H (NEW_SECTION_H (n).sh_link).sh_offset);
8bf761ce
RS		 804 symp = (Elf32_Sym *) (NEW_SECTION_H (n).sh_offset + new_base);
805 symendp = (Elf32_Sym *) ((byte *)symp + NEW_SECTION_H (n).sh_size);
806
807 for (; symp < symendp; symp ++)
808 if (strcmp ((char *) (symnames + symp->st_name), "_end") == 0
809 || strcmp ((char *) (symnames + symp->st_name), "_edata") == 0)
810 memcpy (&symp->st_value, &new_bss_addr, sizeof (new_bss_addr));
811 }
812
48240339
KH		 813#ifdef SOLARIS2
814 /* This loop seeks out relocation sections for the data section, so
815 that it can undo relocations performed by the runtime linker. */
816 for (n = new_file_h->e_shnum - 1; n; n--)
817 {
818 Elf32_Shdr section = NEW_SECTION_H (n);
819 switch (section.sh_type) {
820 default:
821 break;
822 case SHT_REL:
823 case SHT_RELA:
824 /* This code handles two different size structs, but there
825 should be no harm in that provided that r_offset is always
826 the first member. */
827 nn = section.sh_info;
828 if (!strcmp (old_section_names + NEW_SECTION_H (nn).sh_name, ".data")
829 || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name),
830 ".data1"))
831 {
832 Elf32_Addr offset = NEW_SECTION_H (nn).sh_addr -
833 NEW_SECTION_H (nn).sh_offset;
834 caddr_t reloc = old_base + section.sh_offset, end;
835 for (end = reloc + section.sh_size; reloc < end;
836 reloc += section.sh_entsize)
837 {
838 Elf32_Addr addr = ((Elf32_Rel *) reloc)->r_offset - offset;
839 memcpy (new_base + addr, old_base + addr, 4);
840 }
841 }
842 break;
843 }
844 }
845#endif
846
04f903c0
KH		 847#ifdef UNEXEC_USE_MAP_PRIVATE
848 if (lseek (new_file, 0, SEEK_SET) == -1)
849 fatal ("Can't rewind (%s): errno %d\n", new_name, errno);
850
851 if (write (new_file, new_base, new_file_size) != new_file_size)
852 fatal ("Can't write (%s): errno %d\n", new_name, errno);
853#endif
854
8917361f 855 /* Close the files and make the new file executable. */
d427b66a
JB		 856
857 if (close (old_file))
d7cb42c3 858 fatal ("Can't close (%s): errno %d\n", old_name, errno);
d427b66a
JB		 859
860 if (close (new_file))
d7cb42c3 861 fatal ("Can't close (%s): errno %d\n", new_name, errno);
d427b66a
JB		 862
863 if (stat (new_name, &stat_buf) == -1)
d7cb42c3 864 fatal ("Can't stat (%s): errno %d\n", new_name, errno);
d427b66a
JB		 865
866 n = umask (777);
867 umask (n);
868 stat_buf.st_mode |= 0111 & ~n;
869 if (chmod (new_name, stat_buf.st_mode) == -1)
d7cb42c3 870 fatal ("Can't chmod (%s): errno %d\n", new_name, errno);
d427b66a 871}
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