(ospeed): Always use `extern' in the declaration.
[bpt/emacs.git] / src / unexelf.c
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e40c4104
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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
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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
994a65f3 104 0 0 0x1 0
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105
106[2] 5 2 0x80480e8 0xe8 0x388 .hash
994a65f3 107 3 0 0x4 0x4
d427b66a
JB
108
109[3] 11 2 0x8048470 0x470 0x7f0 .dynsym
994a65f3 110 4 1 0x4 0x10
d427b66a
JB
111
112[4] 3 2 0x8048c60 0xc60 0x3ad .dynstr
994a65f3 113 0 0 0x1 0
d427b66a
JB
114
115[5] 9 2 0x8049010 0x1010 0x338 .rel.plt
994a65f3 116 3 7 0x4 0x8
d427b66a
JB
117
118[6] 1 6 0x8049348 0x1348 0x3 .init
994a65f3 119 0 0 0x4 0
d427b66a
JB
120
121[7] 1 6 0x804934c 0x134c 0x680 .plt
994a65f3 122 0 0 0x4 0x4
d427b66a
JB
123
124[8] 1 6 0x80499cc 0x19cc 0x3c56f .text
994a65f3 125 0 0 0x4 0
d427b66a
JB
126
127[9] 1 6 0x8085f3c 0x3df3c 0x3 .fini
994a65f3 128 0 0 0x4 0
d427b66a
JB
129
130[10] 1 2 0x8085f40 0x3df40 0x69c .rodata
994a65f3 131 0 0 0x4 0
d427b66a
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132
133[11] 1 2 0x80865dc 0x3e5dc 0xd51 .rodata1
994a65f3 134 0 0 0x4 0
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135
136[12] 1 3 0x8088330 0x3f330 0x20afc .data
994a65f3 137 0 0 0x4 0
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138
139[13] 1 3 0x80a8e2c 0x5fe2c 0x89d .data1
994a65f3 140 0 0 0x4 0
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JB
141
142[14] 1 3 0x80a96cc 0x606cc 0x1a8 .got
994a65f3 143 0 0 0x4 0x4
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JB
144
145[15] 6 3 0x80a9874 0x60874 0x80 .dynamic
994a65f3 146 4 0 0x4 0x8
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JB
147
148[16] 8 3 0x80a98f4 0x608f4 0x449c .bss
994a65f3 149 0 0 0x4 0
d427b66a
JB
150
151[17] 2 0 0 0x608f4 0x9b90 .symtab
994a65f3 152 18 371 0x4 0x10
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153
154[18] 3 0 0 0x6a484 0x8526 .strtab
994a65f3 155 0 0 0x1 0
d427b66a
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156
157[19] 3 0 0 0x729aa 0x93 .shstrtab
994a65f3 158 0 0 0x1 0
d427b66a
JB
159
160[20] 1 0 0 0x72a3d 0x68b7 .comment
994a65f3 161 0 0 0x1 0
d427b66a
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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
994a65f3 172 0 0 0x1 0
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173
174[2] 5 2 0x80480e8 0xe8 0x388 .hash
994a65f3 175 3 0 0x4 0x4
d427b66a
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176
177[3] 11 2 0x8048470 0x470 0x7f0 .dynsym
994a65f3 178 4 1 0x4 0x10
d427b66a
JB
179
180[4] 3 2 0x8048c60 0xc60 0x3ad .dynstr
994a65f3 181 0 0 0x1 0
d427b66a
JB
182
183[5] 9 2 0x8049010 0x1010 0x338 .rel.plt
994a65f3 184 3 7 0x4 0x8
d427b66a
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185
186[6] 1 6 0x8049348 0x1348 0x3 .init
994a65f3 187 0 0 0x4 0
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188
189[7] 1 6 0x804934c 0x134c 0x680 .plt
994a65f3 190 0 0 0x4 0x4
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191
192[8] 1 6 0x80499cc 0x19cc 0x3c56f .text
994a65f3 193 0 0 0x4 0
d427b66a
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194
195[9] 1 6 0x8085f3c 0x3df3c 0x3 .fini
994a65f3 196 0 0 0x4 0
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197
198[10] 1 2 0x8085f40 0x3df40 0x69c .rodata
994a65f3 199 0 0 0x4 0
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200
201[11] 1 2 0x80865dc 0x3e5dc 0xd51 .rodata1
994a65f3 202 0 0 0x4 0
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203
204[12] 1 3 0x8088330 0x3f330 0x20afc .data
994a65f3 205 0 0 0x4 0
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206
207[13] 1 3 0x80a8e2c 0x5fe2c 0x89d .data1
994a65f3 208 0 0 0x4 0
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209
210[14] 1 3 0x80a96cc 0x606cc 0x1a8 .got
994a65f3 211 0 0 0x4 0x4
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212
213[15] 6 3 0x80a9874 0x60874 0x80 .dynamic
994a65f3 214 4 0 0x4 0x8
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215
216[16] 8 3 0x80c6800 0x7d800 0 .bss
994a65f3 217 0 0 0x4 0
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218
219[17] 2 0 0 0x7d800 0x9b90 .symtab
994a65f3 220 18 371 0x4 0x10
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221
222[18] 3 0 0 0x87390 0x8526 .strtab
994a65f3 223 0 0 0x1 0
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224
225[19] 3 0 0 0x8f8b6 0x93 .shstrtab
994a65f3 226 0 0 0x1 0
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227
228[20] 1 0 0 0x8f949 0x68b7 .comment
994a65f3 229 0 0 0x1 0
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230
231[21] 1 3 0x80a98f4 0x608f4 0x1cf0c .data
994a65f3 232 0 0 0x4 0
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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
994a65f3
RM
2826 0x34 0x8048034 0
2830xa0 0xa0 5 0
d427b66a 284
994a65f3
RM
2853 0xd4 0 0
2860x13 0 4 0
d427b66a 287
994a65f3
RM
2881 0x34 0x8048034 0
2890x3f2f9 0x3f2f9 5 0x1000
d427b66a 290
994a65f3
RM
2911 0x3f330 0x8088330 0
2920x215c4 0x25a60 7 0x1000
d427b66a 293
994a65f3
RM
2942 0x60874 0x80a9874 0
2950x80 0 7 0
d427b66a
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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
994a65f3
RM
3046 0x34 0x8048034 0
3050xa0 0xa0 5 0
d427b66a 306
994a65f3
RM
3073 0xd4 0 0
3080x13 0 4 0
d427b66a 309
994a65f3
RM
3101 0x34 0x8048034 0
3110x3f2f9 0x3f2f9 5 0x1000
d427b66a 312
994a65f3
RM
3131 0x3f330 0x8088330 0
3140x3e4d0 0x3e4d0 7 0x1000
d427b66a 315
994a65f3
RM
3162 0x60874 0x80a9874 0
3170x80 0 7 0
d427b66a
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318
319
320 */
e40c4104 321\f
994a65f3
RM
322/* Modified by wtien@urbana.mcd.mot.com of Motorola Inc.
323 *
e40c4104 324 * The above mechanism does not work if the unexeced ELF file is being
994a65f3 325 * re-layout by other applications (such as `strip'). All the applications
e40c4104 326 * that re-layout the internal of ELF will layout all sections in ascending
994a65f3
RM
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
e40c4104 329 * is now being pushed far away down, and causes part of it not to be mapped
994a65f3 330 * in (ie. not covered by the load segment entry in PHDR vector), therefore
e40c4104
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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
994a65f3
RM
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
e40c4104 338 * by macro PATCH_INDEX. All the fields that need to be patched are:
994a65f3 339 *
e40c4104
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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
994a65f3 351 0 0 0x1 0
d427b66a 352
e40c4104 353[2] 5 2 0x80480e8 0xe8 0x388 .hash
994a65f3 354 3 0 0x4 0x4
e40c4104
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355
356[3] 11 2 0x8048470 0x470 0x7f0 .dynsym
994a65f3 357 4 1 0x4 0x10
e40c4104
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358
359[4] 3 2 0x8048c60 0xc60 0x3ad .dynstr
994a65f3 360 0 0 0x1 0
e40c4104
RS
361
362[5] 9 2 0x8049010 0x1010 0x338 .rel.plt
994a65f3 363 3 7 0x4 0x8
e40c4104
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364
365[6] 1 6 0x8049348 0x1348 0x3 .init
994a65f3 366 0 0 0x4 0
e40c4104
RS
367
368[7] 1 6 0x804934c 0x134c 0x680 .plt
994a65f3 369 0 0 0x4 0x4
e40c4104
RS
370
371[8] 1 6 0x80499cc 0x19cc 0x3c56f .text
994a65f3 372 0 0 0x4 0
e40c4104
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373
374[9] 1 6 0x8085f3c 0x3df3c 0x3 .fini
994a65f3 375 0 0 0x4 0
e40c4104
RS
376
377[10] 1 2 0x8085f40 0x3df40 0x69c .rodata
994a65f3 378 0 0 0x4 0
e40c4104
RS
379
380[11] 1 2 0x80865dc 0x3e5dc 0xd51 .rodata1
994a65f3 381 0 0 0x4 0
e40c4104
RS
382
383[12] 1 3 0x8088330 0x3f330 0x20afc .data
994a65f3 384 0 0 0x4 0
e40c4104
RS
385
386[13] 1 3 0x80a8e2c 0x5fe2c 0x89d .data1
994a65f3 387 0 0 0x4 0
e40c4104
RS
388
389[14] 1 3 0x80a96cc 0x606cc 0x1a8 .got
994a65f3 390 0 0 0x4 0x4
e40c4104
RS
391
392[15] 6 3 0x80a9874 0x60874 0x80 .dynamic
994a65f3 393 4 0 0x4 0x8
e40c4104
RS
394
395[16] 1 3 0x80a98f4 0x608f4 0x1cf0c .data
994a65f3 396 0 0 0x4 0
e40c4104
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397
398[17] 8 3 0x80c6800 0x7d800 0 .bss
994a65f3 399 0 0 0x4 0
e40c4104
RS
400
401[18] 2 0 0 0x7d800 0x9b90 .symtab
994a65f3 402 19 371 0x4 0x10
e40c4104
RS
403
404[19] 3 0 0 0x87390 0x8526 .strtab
994a65f3 405 0 0 0x1 0
e40c4104
RS
406
407[20] 3 0 0 0x8f8b6 0x93 .shstrtab
994a65f3 408 0 0 0x1 0
e40c4104
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409
410[21] 1 0 0 0x8f949 0x68b7 .comment
994a65f3 411 0 0 0x1 0
e40c4104
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412
413 */
414\f
d427b66a
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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
265b2695
RS
426#ifdef __alpha__
427# include <sym.h> /* get COFF debugging symbol table declaration */
428#endif
429
430#if __GNU_LIBRARY__ - 0 >= 6
431# include <link.h> /* get ElfW etc */
432#endif
433
434#ifndef ElfW
435# ifdef __STDC__
436# define ElfW(type) Elf32_##type
437# else
438# define ElfW(type) Elf32_/**/type
439# endif
440#endif
441
d427b66a 442#ifndef emacs
d7cb42c3 443#define fatal(a, b, c) fprintf (stderr, a, b, c), exit (1)
d427b66a 444#else
82142eb0 445#include <config.h>
d7cb42c3 446extern void fatal (char *, ...);
d427b66a
JB
447#endif
448
d8858cfe
RS
449#ifndef ELF_BSS_SECTION_NAME
450#define ELF_BSS_SECTION_NAME ".bss"
451#endif
452
d427b66a
JB
453/* Get the address of a particular section or program header entry,
454 * accounting for the size of the entries.
455 */
ea083293
RS
456/*
457 On PPC Reference Platform running Solaris 2.5.1
458 the plt section is also of type NOBI like the bss section.
459 (not really stored) and therefore sections after the bss
460 section start at the plt offset. The plt section is always
461 the one just before the bss section.
462 Thus, we modify the test from
463 if (NEW_SECTION_H (nn).sh_offset >= new_data2_offset)
464 to
465 if (NEW_SECTION_H (nn).sh_offset >=
466 OLD_SECTION_H (old_bss_index-1).sh_offset)
467 This is just a hack. We should put the new data section
468 before the .plt section.
469 And we should not have this routine at all but use
470 the libelf library to read the old file and create the new
471 file.
472 The changed code is minimal and depends on prep set in m/prep.h
473 Erik Deumens
474 Quantum Theory Project
475 University of Florida
476 deumens@qtp.ufl.edu
477 Apr 23, 1996
478 */
d427b66a
JB
479
480#define OLD_SECTION_H(n) \
265b2695 481 (*(ElfW(Shdr) *) ((byte *) old_section_h + old_file_h->e_shentsize * (n)))
d427b66a 482#define NEW_SECTION_H(n) \
265b2695 483 (*(ElfW(Shdr) *) ((byte *) new_section_h + new_file_h->e_shentsize * (n)))
d427b66a 484#define OLD_PROGRAM_H(n) \
265b2695 485 (*(ElfW(Phdr) *) ((byte *) old_program_h + old_file_h->e_phentsize * (n)))
d427b66a 486#define NEW_PROGRAM_H(n) \
265b2695 487 (*(ElfW(Phdr) *) ((byte *) new_program_h + new_file_h->e_phentsize * (n)))
d427b66a 488
e40c4104
RS
489#define PATCH_INDEX(n) \
490 do { \
d7cb42c3 491 if ((int) (n) >= old_bss_index) \
e40c4104 492 (n)++; } while (0)
d427b66a
JB
493typedef unsigned char byte;
494
e40c4104
RS
495/* Round X up to a multiple of Y. */
496
497int
498round_up (x, y)
499 int x, y;
500{
501 int rem = x % y;
502 if (rem == 0)
503 return x;
504 return x - rem + y;
505}
506
d427b66a
JB
507/* ****************************************************************
508 * unexec
509 *
510 * driving logic.
511 *
512 * In ELF, this works by replacing the old .bss section with a new
513 * .data section, and inserting an empty .bss immediately afterwards.
514 *
515 */
516void
517unexec (new_name, old_name, data_start, bss_start, entry_address)
518 char *new_name, *old_name;
519 unsigned data_start, bss_start, entry_address;
520{
d427b66a
JB
521 int new_file, old_file, new_file_size;
522
523 /* Pointers to the base of the image of the two files. */
524 caddr_t old_base, new_base;
525
526 /* Pointers to the file, program and section headers for the old and new
527 * files.
528 */
265b2695
RS
529 ElfW(Ehdr) *old_file_h, *new_file_h;
530 ElfW(Phdr) *old_program_h, *new_program_h;
531 ElfW(Shdr) *old_section_h, *new_section_h;
d427b66a
JB
532
533 /* Point to the section name table in the old file */
534 char *old_section_names;
535
265b2695
RS
536 ElfW(Addr) old_bss_addr, new_bss_addr;
537 ElfW(Word) old_bss_size, new_data2_size;
538 ElfW(Off) new_data2_offset;
539 ElfW(Addr) new_data2_addr;
d427b66a 540
d283640e 541 int n, nn, old_bss_index, old_data_index, new_data2_index;
d427b66a
JB
542 struct stat stat_buf;
543
544 /* Open the old file & map it into the address space. */
545
546 old_file = open (old_name, O_RDONLY);
547
548 if (old_file < 0)
549 fatal ("Can't open %s for reading: errno %d\n", old_name, errno);
550
551 if (fstat (old_file, &stat_buf) == -1)
d7cb42c3 552 fatal ("Can't fstat (%s): errno %d\n", old_name, errno);
d427b66a
JB
553
554 old_base = mmap (0, stat_buf.st_size, PROT_READ, MAP_SHARED, old_file, 0);
555
556 if (old_base == (caddr_t) -1)
d7cb42c3 557 fatal ("Can't mmap (%s): errno %d\n", old_name, errno);
d427b66a
JB
558
559#ifdef DEBUG
d283640e
KH
560 fprintf (stderr, "mmap (%s, %x) -> %x\n", old_name, stat_buf.st_size,
561 old_base);
d427b66a
JB
562#endif
563
564 /* Get pointers to headers & section names */
565
265b2695
RS
566 old_file_h = (ElfW(Ehdr) *) old_base;
567 old_program_h = (ElfW(Phdr) *) ((byte *) old_base + old_file_h->e_phoff);
568 old_section_h = (ElfW(Shdr) *) ((byte *) old_base + old_file_h->e_shoff);
d427b66a 569 old_section_names = (char *) old_base
d7cb42c3 570 + OLD_SECTION_H (old_file_h->e_shstrndx).sh_offset;
d427b66a
JB
571
572 /* Find the old .bss section. Figure out parameters of the new
573 * data2 and bss sections.
574 */
575
d7cb42c3
RS
576 for (old_bss_index = 1; old_bss_index < (int) old_file_h->e_shnum;
577 old_bss_index++)
d427b66a
JB
578 {
579#ifdef DEBUG
580 fprintf (stderr, "Looking for .bss - found %s\n",
d7cb42c3 581 old_section_names + OLD_SECTION_H (old_bss_index).sh_name);
d427b66a 582#endif
d7cb42c3 583 if (!strcmp (old_section_names + OLD_SECTION_H (old_bss_index).sh_name,
d8858cfe 584 ELF_BSS_SECTION_NAME))
d427b66a
JB
585 break;
586 }
587 if (old_bss_index == old_file_h->e_shnum)
588 fatal ("Can't find .bss in %s.\n", old_name, 0);
589
d7cb42c3
RS
590 old_bss_addr = OLD_SECTION_H (old_bss_index).sh_addr;
591 old_bss_size = OLD_SECTION_H (old_bss_index).sh_size;
d427b66a 592#if defined(emacs) || !defined(DEBUG)
265b2695 593 new_bss_addr = (ElfW(Addr)) sbrk (0);
d427b66a
JB
594#else
595 new_bss_addr = old_bss_addr + old_bss_size + 0x1234;
596#endif
597 new_data2_addr = old_bss_addr;
598 new_data2_size = new_bss_addr - old_bss_addr;
d7cb42c3 599 new_data2_offset = OLD_SECTION_H (old_bss_index).sh_offset;
d427b66a
JB
600
601#ifdef DEBUG
602 fprintf (stderr, "old_bss_index %d\n", old_bss_index);
d283640e
KH
603 fprintf (stderr, "old_bss_addr %x\n", old_bss_addr);
604 fprintf (stderr, "old_bss_size %x\n", old_bss_size);
605 fprintf (stderr, "new_bss_addr %x\n", new_bss_addr);
606 fprintf (stderr, "new_data2_addr %x\n", new_data2_addr);
607 fprintf (stderr, "new_data2_size %x\n", new_data2_size);
608 fprintf (stderr, "new_data2_offset %x\n", new_data2_offset);
d427b66a
JB
609#endif
610
d283640e 611 if ((unsigned) new_bss_addr < (unsigned) old_bss_addr + old_bss_size)
d427b66a
JB
612 fatal (".bss shrank when undumping???\n", 0, 0);
613
d7cb42c3 614 /* Set the output file to the right size and mmap it. Set
d427b66a
JB
615 * pointers to various interesting objects. stat_buf still has
616 * old_file data.
617 */
618
619 new_file = open (new_name, O_RDWR | O_CREAT, 0666);
620 if (new_file < 0)
d7cb42c3 621 fatal ("Can't creat (%s): errno %d\n", new_name, errno);
d427b66a
JB
622
623 new_file_size = stat_buf.st_size + old_file_h->e_shentsize + new_data2_size;
624
625 if (ftruncate (new_file, new_file_size))
d7cb42c3 626 fatal ("Can't ftruncate (%s): errno %d\n", new_name, errno);
d427b66a 627
04f903c0
KH
628#ifdef UNEXEC_USE_MAP_PRIVATE
629 new_base = mmap (0, new_file_size, PROT_READ | PROT_WRITE, MAP_PRIVATE,
630 new_file, 0);
631#else
d427b66a
JB
632 new_base = mmap (0, new_file_size, PROT_READ | PROT_WRITE, MAP_SHARED,
633 new_file, 0);
04f903c0 634#endif
d427b66a
JB
635
636 if (new_base == (caddr_t) -1)
d7cb42c3 637 fatal ("Can't mmap (%s): errno %d\n", new_name, errno);
d427b66a 638
265b2695
RS
639 new_file_h = (ElfW(Ehdr) *) new_base;
640 new_program_h = (ElfW(Phdr) *) ((byte *) new_base + old_file_h->e_phoff);
641 new_section_h = (ElfW(Shdr) *)
d427b66a
JB
642 ((byte *) new_base + old_file_h->e_shoff + new_data2_size);
643
644 /* Make our new file, program and section headers as copies of the
645 * originals.
646 */
647
648 memcpy (new_file_h, old_file_h, old_file_h->e_ehsize);
649 memcpy (new_program_h, old_program_h,
650 old_file_h->e_phnum * old_file_h->e_phentsize);
e40c4104
RS
651
652 /* Modify the e_shstrndx if necessary. */
653 PATCH_INDEX (new_file_h->e_shstrndx);
d427b66a
JB
654
655 /* Fix up file header. We'll add one section. Section header is
656 * further away now.
657 */
658
659 new_file_h->e_shoff += new_data2_size;
660 new_file_h->e_shnum += 1;
661
662#ifdef DEBUG
d283640e 663 fprintf (stderr, "Old section offset %x\n", old_file_h->e_shoff);
d427b66a 664 fprintf (stderr, "Old section count %d\n", old_file_h->e_shnum);
d283640e 665 fprintf (stderr, "New section offset %x\n", new_file_h->e_shoff);
d427b66a
JB
666 fprintf (stderr, "New section count %d\n", new_file_h->e_shnum);
667#endif
668
669 /* Fix up a new program header. Extend the writable data segment so
670 * that the bss area is covered too. Find that segment by looking
671 * for a segment that ends just before the .bss area. Make sure
672 * that no segments are above the new .data2. Put a loop at the end
673 * to adjust the offset and address of any segment that is above
674 * data2, just in case we decide to allow this later.
675 */
676
677 for (n = new_file_h->e_phnum - 1; n >= 0; n--)
678 {
e40c4104 679 /* Compute maximum of all requirements for alignment of section. */
d283640e 680 int alignment = (NEW_PROGRAM_H (n)).p_align;
e40c4104
RS
681 if ((OLD_SECTION_H (old_bss_index)).sh_addralign > alignment)
682 alignment = OLD_SECTION_H (old_bss_index).sh_addralign;
683
d7cb42c3 684 if (NEW_PROGRAM_H (n).p_vaddr + NEW_PROGRAM_H (n).p_filesz > old_bss_addr)
d427b66a
JB
685 fatal ("Program segment above .bss in %s\n", old_name, 0);
686
d7cb42c3 687 if (NEW_PROGRAM_H (n).p_type == PT_LOAD
e40c4104
RS
688 && (round_up ((NEW_PROGRAM_H (n)).p_vaddr
689 + (NEW_PROGRAM_H (n)).p_filesz,
690 alignment)
691 == round_up (old_bss_addr, alignment)))
d427b66a
JB
692 break;
693 }
694 if (n < 0)
695 fatal ("Couldn't find segment next to .bss in %s\n", old_name, 0);
696
d7cb42c3
RS
697 NEW_PROGRAM_H (n).p_filesz += new_data2_size;
698 NEW_PROGRAM_H (n).p_memsz = NEW_PROGRAM_H (n).p_filesz;
d427b66a
JB
699
700#if 0 /* Maybe allow section after data2 - does this ever happen? */
701 for (n = new_file_h->e_phnum - 1; n >= 0; n--)
702 {
d7cb42c3
RS
703 if (NEW_PROGRAM_H (n).p_vaddr
704 && NEW_PROGRAM_H (n).p_vaddr >= new_data2_addr)
705 NEW_PROGRAM_H (n).p_vaddr += new_data2_size - old_bss_size;
d427b66a 706
d7cb42c3
RS
707 if (NEW_PROGRAM_H (n).p_offset >= new_data2_offset)
708 NEW_PROGRAM_H (n).p_offset += new_data2_size;
d427b66a
JB
709 }
710#endif
711
712 /* Fix up section headers based on new .data2 section. Any section
713 * whose offset or virtual address is after the new .data2 section
714 * gets its value adjusted. .bss size becomes zero and new address
715 * is set. data2 section header gets added by copying the existing
716 * .data header and modifying the offset, address and size.
717 */
d7cb42c3 718 for (old_data_index = 1; old_data_index < (int) old_file_h->e_shnum;
d427b66a 719 old_data_index++)
d7cb42c3 720 if (!strcmp (old_section_names + OLD_SECTION_H (old_data_index).sh_name,
d427b66a
JB
721 ".data"))
722 break;
723 if (old_data_index == old_file_h->e_shnum)
724 fatal ("Can't find .data in %s.\n", old_name, 0);
725
994a65f3 726 /* Walk through all section headers, insert the new data2 section right
e40c4104 727 before the new bss section. */
d7cb42c3 728 for (n = 1, nn = 1; n < (int) old_file_h->e_shnum; n++, nn++)
d427b66a
JB
729 {
730 caddr_t src;
e40c4104
RS
731 /* If it is bss section, insert the new data2 section before it. */
732 if (n == old_bss_index)
733 {
734 /* Steal the data section header for this data2 section. */
d7cb42c3 735 memcpy (&NEW_SECTION_H (nn), &OLD_SECTION_H (old_data_index),
e40c4104 736 new_file_h->e_shentsize);
994a65f3 737
d7cb42c3
RS
738 NEW_SECTION_H (nn).sh_addr = new_data2_addr;
739 NEW_SECTION_H (nn).sh_offset = new_data2_offset;
740 NEW_SECTION_H (nn).sh_size = new_data2_size;
e40c4104
RS
741 /* Use the bss section's alignment. This will assure that the
742 new data2 section always be placed in the same spot as the old
743 bss section by any other application. */
d7cb42c3 744 NEW_SECTION_H (nn).sh_addralign = OLD_SECTION_H (n).sh_addralign;
e40c4104
RS
745
746 /* Now copy over what we have in the memory now. */
994a65f3
RM
747 memcpy (NEW_SECTION_H (nn).sh_offset + new_base,
748 (caddr_t) OLD_SECTION_H (n).sh_addr,
e40c4104
RS
749 new_data2_size);
750 nn++;
751 }
994a65f3
RM
752
753 memcpy (&NEW_SECTION_H (nn), &OLD_SECTION_H (n),
e40c4104 754 old_file_h->e_shentsize);
994a65f3 755
e40c4104
RS
756 /* The new bss section's size is zero, and its file offset and virtual
757 address should be off by NEW_DATA2_SIZE. */
758 if (n == old_bss_index)
759 {
760 /* NN should be `old_bss_index + 1' at this point. */
d7cb42c3
RS
761 NEW_SECTION_H (nn).sh_offset += new_data2_size;
762 NEW_SECTION_H (nn).sh_addr += new_data2_size;
e40c4104 763 /* Let the new bss section address alignment be the same as the
994a65f3 764 section address alignment followed the old bss section, so
e40c4104 765 this section will be placed in exactly the same place. */
d7cb42c3
RS
766 NEW_SECTION_H (nn).sh_addralign = OLD_SECTION_H (nn).sh_addralign;
767 NEW_SECTION_H (nn).sh_size = 0;
e40c4104 768 }
85b2e0ee
RS
769 else
770 {
771 /* Any section that was original placed AFTER the bss
772 section should now be off by NEW_DATA2_SIZE. */
ea083293
RS
773#ifdef SOLARIS_POWERPC
774 /* On PPC Reference Platform running Solaris 2.5.1
775 the plt section is also of type NOBI like the bss section.
776 (not really stored) and therefore sections after the bss
777 section start at the plt offset. The plt section is always
778 the one just before the bss section.
779 It would be better to put the new data section before
780 the .plt section, or use libelf instead.
781 Erik Deumens, deumens@qtp.ufl.edu. */
782 if (NEW_SECTION_H (nn).sh_offset
783 >= OLD_SECTION_H (old_bss_index-1).sh_offset)
784 NEW_SECTION_H (nn).sh_offset += new_data2_size;
785#else
faee8ef0
RS
786 if (round_up (NEW_SECTION_H (nn).sh_offset,
787 OLD_SECTION_H (old_bss_index).sh_addralign)
788 >= new_data2_offset)
85b2e0ee 789 NEW_SECTION_H (nn).sh_offset += new_data2_size;
ea083293 790#endif
85b2e0ee
RS
791 /* Any section that was originally placed after the section
792 header table should now be off by the size of one section
793 header table entry. */
794 if (NEW_SECTION_H (nn).sh_offset > new_file_h->e_shoff)
795 NEW_SECTION_H (nn).sh_offset += new_file_h->e_shentsize;
796 }
797
e40c4104 798 /* If any section hdr refers to the section after the new .data
994a65f3 799 section, make it refer to next one because we have inserted
8917361f 800 a new section in between. */
994a65f3 801
d7cb42c3 802 PATCH_INDEX (NEW_SECTION_H (nn).sh_link);
8917361f
RS
803 /* For symbol tables, info is a symbol table index,
804 so don't change it. */
805 if (NEW_SECTION_H (nn).sh_type != SHT_SYMTAB
806 && NEW_SECTION_H (nn).sh_type != SHT_DYNSYM)
807 PATCH_INDEX (NEW_SECTION_H (nn).sh_info);
808
809 /* Now, start to copy the content of sections. */
d7cb42c3
RS
810 if (NEW_SECTION_H (nn).sh_type == SHT_NULL
811 || NEW_SECTION_H (nn).sh_type == SHT_NOBITS)
d427b66a 812 continue;
994a65f3 813
e40c4104 814 /* Write out the sections. .data and .data1 (and data2, called
8917361f
RS
815 ".data" in the strings table) get copied from the current process
816 instead of the old file. */
d7cb42c3
RS
817 if (!strcmp (old_section_names + NEW_SECTION_H (n).sh_name, ".data")
818 || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name),
d427b66a 819 ".data1"))
d7cb42c3 820 src = (caddr_t) OLD_SECTION_H (n).sh_addr;
d427b66a 821 else
d7cb42c3 822 src = old_base + OLD_SECTION_H (n).sh_offset;
994a65f3 823
d7cb42c3
RS
824 memcpy (NEW_SECTION_H (nn).sh_offset + new_base, src,
825 NEW_SECTION_H (nn).sh_size);
e40c4104 826
265b2695
RS
827#ifdef __alpha__
828 /* Update Alpha COFF symbol table: */
829 if (strcmp (old_section_names + OLD_SECTION_H (n).sh_name, ".mdebug")
830 == 0)
831 {
832 pHDRR symhdr = (pHDRR) (NEW_SECTION_H (nn).sh_offset + new_base);
833
834 symhdr->cbLineOffset += new_data2_size;
835 symhdr->cbDnOffset += new_data2_size;
836 symhdr->cbPdOffset += new_data2_size;
837 symhdr->cbSymOffset += new_data2_size;
838 symhdr->cbOptOffset += new_data2_size;
839 symhdr->cbAuxOffset += new_data2_size;
840 symhdr->cbSsOffset += new_data2_size;
841 symhdr->cbSsExtOffset += new_data2_size;
842 symhdr->cbFdOffset += new_data2_size;
843 symhdr->cbRfdOffset += new_data2_size;
844 symhdr->cbExtOffset += new_data2_size;
845 }
846#endif /* __alpha__ */
847
8917361f 848 /* If it is the symbol table, its st_shndx field needs to be patched. */
d7cb42c3
RS
849 if (NEW_SECTION_H (nn).sh_type == SHT_SYMTAB
850 || NEW_SECTION_H (nn).sh_type == SHT_DYNSYM)
e40c4104 851 {
265b2695 852 ElfW(Shdr) *spt = &NEW_SECTION_H (nn);
e40c4104 853 unsigned int num = spt->sh_size / spt->sh_entsize;
265b2695 854 ElfW(Sym) * sym = (ElfW(Sym) *) (NEW_SECTION_H (nn).sh_offset +
e40c4104
RS
855 new_base);
856 for (; num--; sym++)
857 {
858 if ((sym->st_shndx == SHN_UNDEF)
859 || (sym->st_shndx == SHN_ABS)
860 || (sym->st_shndx == SHN_COMMON))
861 continue;
994a65f3 862
d7cb42c3 863 PATCH_INDEX (sym->st_shndx);
e40c4104
RS
864 }
865 }
d427b66a
JB
866 }
867
8917361f 868 /* Update the symbol values of _edata and _end. */
8bf761ce
RS
869 for (n = new_file_h->e_shnum - 1; n; n--)
870 {
871 byte *symnames;
265b2695 872 ElfW(Sym) *symp, *symendp;
8bf761ce
RS
873
874 if (NEW_SECTION_H (n).sh_type != SHT_DYNSYM
875 && NEW_SECTION_H (n).sh_type != SHT_SYMTAB)
876 continue;
877
8c1e9afe
KH
878 symnames = ((byte *) new_base
879 + NEW_SECTION_H (NEW_SECTION_H (n).sh_link).sh_offset);
265b2695
RS
880 symp = (ElfW(Sym) *) (NEW_SECTION_H (n).sh_offset + new_base);
881 symendp = (ElfW(Sym) *) ((byte *)symp + NEW_SECTION_H (n).sh_size);
8bf761ce
RS
882
883 for (; symp < symendp; symp ++)
884 if (strcmp ((char *) (symnames + symp->st_name), "_end") == 0
885 || strcmp ((char *) (symnames + symp->st_name), "_edata") == 0)
886 memcpy (&symp->st_value, &new_bss_addr, sizeof (new_bss_addr));
887 }
888
48240339
KH
889 /* This loop seeks out relocation sections for the data section, so
890 that it can undo relocations performed by the runtime linker. */
891 for (n = new_file_h->e_shnum - 1; n; n--)
892 {
265b2695 893 ElfW(Shdr) section = NEW_SECTION_H (n);
48240339
KH
894 switch (section.sh_type) {
895 default:
896 break;
897 case SHT_REL:
898 case SHT_RELA:
994a65f3
RM
899 /* This code handles two different size structs, but there should
900 be no harm in that provided that r_offset is always the first
901 member. */
48240339
KH
902 nn = section.sh_info;
903 if (!strcmp (old_section_names + NEW_SECTION_H (nn).sh_name, ".data")
904 || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name),
905 ".data1"))
906 {
265b2695 907 ElfW(Addr) offset = NEW_SECTION_H (nn).sh_addr -
48240339
KH
908 NEW_SECTION_H (nn).sh_offset;
909 caddr_t reloc = old_base + section.sh_offset, end;
910 for (end = reloc + section.sh_size; reloc < end;
911 reloc += section.sh_entsize)
912 {
265b2695
RS
913 ElfW(Addr) addr = ((ElfW(Rel) *) reloc)->r_offset - offset;
914#ifdef __alpha__
915 /* The Alpha ELF binutils currently have a bug that
916 sometimes results in relocs that contain all
917 zeroes. Work around this for now... */
918 if (((ElfW(Rel) *) reloc)->r_offset == 0)
919 continue;
920#endif
921 memcpy (new_base + addr, old_base + addr, sizeof(ElfW(Addr)));
48240339
KH
922 }
923 }
924 break;
925 }
926 }
48240339 927
04f903c0
KH
928#ifdef UNEXEC_USE_MAP_PRIVATE
929 if (lseek (new_file, 0, SEEK_SET) == -1)
930 fatal ("Can't rewind (%s): errno %d\n", new_name, errno);
931
932 if (write (new_file, new_base, new_file_size) != new_file_size)
933 fatal ("Can't write (%s): errno %d\n", new_name, errno);
934#endif
935
8917361f 936 /* Close the files and make the new file executable. */
d427b66a
JB
937
938 if (close (old_file))
d7cb42c3 939 fatal ("Can't close (%s): errno %d\n", old_name, errno);
d427b66a
JB
940
941 if (close (new_file))
d7cb42c3 942 fatal ("Can't close (%s): errno %d\n", new_name, errno);
d427b66a
JB
943
944 if (stat (new_name, &stat_buf) == -1)
d7cb42c3 945 fatal ("Can't stat (%s): errno %d\n", new_name, errno);
d427b66a
JB
946
947 n = umask (777);
948 umask (n);
949 stat_buf.st_mode |= 0111 & ~n;
950 if (chmod (new_name, stat_buf.st_mode) == -1)
d7cb42c3 951 fatal ("Can't chmod (%s): errno %d\n", new_name, errno);
d427b66a 952}