0
|
1 /* Copyright (C) 1985, 1986, 1987, 1988, 1990, 1992, 1993
|
|
2 Free Software Foundation, Inc.
|
|
3
|
|
4 This file is part of XEmacs.
|
|
5
|
|
6 XEmacs is free software; you can redistribute it and/or modify it
|
|
7 under the terms of the GNU General Public License as published by the
|
|
8 Free Software Foundation; either version 2, or (at your option) any
|
|
9 later version.
|
|
10
|
|
11 XEmacs is distributed in the hope that it will be useful, but WITHOUT
|
|
12 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
|
|
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
|
|
14 for more details.
|
|
15
|
|
16 You should have received a copy of the GNU General Public License
|
|
17 along with XEmacs; see the file COPYING. If not, write to
|
|
18 the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
|
|
19 Boston, MA 02111-1307, USA. */
|
|
20
|
255
|
21 /* Synched up with: FSF 20.2. */
|
0
|
22
|
|
23 /*
|
|
24 * unexec.c - Convert a running program into an a.out file.
|
|
25 *
|
|
26 * Author: Spencer W. Thomas
|
|
27 * Computer Science Dept.
|
|
28 * University of Utah
|
|
29 * Date: Tue Mar 2 1982
|
|
30 * Modified heavily since then.
|
|
31 *
|
|
32 * Synopsis:
|
|
33 * unexec (new_name, a_name, data_start, bss_start, entry_address)
|
|
34 * char *new_name, *a_name;
|
|
35 * unsigned data_start, bss_start, entry_address;
|
|
36 *
|
|
37 * Takes a snapshot of the program and makes an a.out format file in the
|
|
38 * file named by the string argument new_name.
|
|
39 * If a_name is non-NULL, the symbol table will be taken from the given file.
|
|
40 * On some machines, an existing a_name file is required.
|
|
41 *
|
|
42 * The boundaries within the a.out file may be adjusted with the data_start
|
|
43 * and bss_start arguments. Either or both may be given as 0 for defaults.
|
|
44 *
|
|
45 * Data_start gives the boundary between the text segment and the data
|
|
46 * segment of the program. The text segment can contain shared, read-only
|
|
47 * program code and literal data, while the data segment is always unshared
|
|
48 * and unprotected. Data_start gives the lowest unprotected address.
|
|
49 * The value you specify may be rounded down to a suitable boundary
|
|
50 * as required by the machine you are using.
|
|
51 *
|
|
52 * Specifying zero for data_start means the boundary between text and data
|
|
53 * should not be the same as when the program was loaded.
|
|
54 * If NO_REMAP is defined, the argument data_start is ignored and the
|
|
55 * segment boundaries are never changed.
|
|
56 *
|
|
57 * Bss_start indicates how much of the data segment is to be saved in the
|
|
58 * a.out file and restored when the program is executed. It gives the lowest
|
|
59 * unsaved address, and is rounded up to a page boundary. The default when 0
|
|
60 * is given assumes that the entire data segment is to be stored, including
|
|
61 * the previous data and bss as well as any additional storage allocated with
|
|
62 * break (2).
|
|
63 *
|
|
64 * The new file is set up to start at entry_address.
|
|
65 *
|
|
66 * If you make improvements I'd like to get them too.
|
|
67 * harpo!utah-cs!thomas, thomas@Utah-20
|
|
68 *
|
|
69 */
|
|
70
|
|
71 /* Even more heavily modified by james@bigtex.cactus.org of Dell Computer Co.
|
|
72 * ELF support added.
|
|
73 *
|
|
74 * Basic theory: the data space of the running process needs to be
|
|
75 * dumped to the output file. Normally we would just enlarge the size
|
|
76 * of .data, scooting everything down. But we can't do that in ELF,
|
|
77 * because there is often something between the .data space and the
|
|
78 * .bss space.
|
|
79 *
|
|
80 * In the temacs dump below, notice that the Global Offset Table
|
|
81 * (.got) and the Dynamic link data (.dynamic) come between .data1 and
|
|
82 * .bss. It does not work to overlap .data with these fields.
|
|
83 *
|
|
84 * The solution is to create a new .data segment. This segment is
|
|
85 * filled with data from the current process. Since the contents of
|
|
86 * various sections refer to sections by index, the new .data segment
|
|
87 * is made the last in the table to avoid changing any existing index.
|
|
88
|
|
89 * This is an example of how the section headers are changed. "Addr"
|
|
90 * is a process virtual address. "Offset" is a file offset.
|
|
91
|
|
92 raid:/nfs/raid/src/dist-18.56/src> dump -h temacs
|
|
93
|
|
94 temacs:
|
|
95
|
|
96 **** SECTION HEADER TABLE ****
|
|
97 [No] Type Flags Addr Offset Size Name
|
|
98 Link Info Adralgn Entsize
|
|
99
|
|
100 [1] 1 2 0x80480d4 0xd4 0x13 .interp
|
|
101 0 0 0x1 0
|
|
102
|
|
103 [2] 5 2 0x80480e8 0xe8 0x388 .hash
|
|
104 3 0 0x4 0x4
|
|
105
|
|
106 [3] 11 2 0x8048470 0x470 0x7f0 .dynsym
|
|
107 4 1 0x4 0x10
|
|
108
|
|
109 [4] 3 2 0x8048c60 0xc60 0x3ad .dynstr
|
|
110 0 0 0x1 0
|
|
111
|
|
112 [5] 9 2 0x8049010 0x1010 0x338 .rel.plt
|
|
113 3 7 0x4 0x8
|
|
114
|
|
115 [6] 1 6 0x8049348 0x1348 0x3 .init
|
|
116 0 0 0x4 0
|
|
117
|
|
118 [7] 1 6 0x804934c 0x134c 0x680 .plt
|
|
119 0 0 0x4 0x4
|
|
120
|
|
121 [8] 1 6 0x80499cc 0x19cc 0x3c56f .text
|
|
122 0 0 0x4 0
|
|
123
|
|
124 [9] 1 6 0x8085f3c 0x3df3c 0x3 .fini
|
|
125 0 0 0x4 0
|
|
126
|
|
127 [10] 1 2 0x8085f40 0x3df40 0x69c .rodata
|
|
128 0 0 0x4 0
|
|
129
|
|
130 [11] 1 2 0x80865dc 0x3e5dc 0xd51 .rodata1
|
|
131 0 0 0x4 0
|
|
132
|
|
133 [12] 1 3 0x8088330 0x3f330 0x20afc .data
|
|
134 0 0 0x4 0
|
|
135
|
|
136 [13] 1 3 0x80a8e2c 0x5fe2c 0x89d .data1
|
|
137 0 0 0x4 0
|
|
138
|
|
139 [14] 1 3 0x80a96cc 0x606cc 0x1a8 .got
|
|
140 0 0 0x4 0x4
|
|
141
|
|
142 [15] 6 3 0x80a9874 0x60874 0x80 .dynamic
|
|
143 4 0 0x4 0x8
|
|
144
|
|
145 [16] 8 3 0x80a98f4 0x608f4 0x449c .bss
|
|
146 0 0 0x4 0
|
|
147
|
|
148 [17] 2 0 0 0x608f4 0x9b90 .symtab
|
|
149 18 371 0x4 0x10
|
|
150
|
|
151 [18] 3 0 0 0x6a484 0x8526 .strtab
|
|
152 0 0 0x1 0
|
|
153
|
|
154 [19] 3 0 0 0x729aa 0x93 .shstrtab
|
|
155 0 0 0x1 0
|
|
156
|
|
157 [20] 1 0 0 0x72a3d 0x68b7 .comment
|
|
158 0 0 0x1 0
|
|
159
|
|
160 raid:/nfs/raid/src/dist-18.56/src> dump -h xemacs
|
|
161
|
|
162 xemacs:
|
|
163
|
|
164 **** SECTION HEADER TABLE ****
|
|
165 [No] Type Flags Addr Offset Size Name
|
|
166 Link Info Adralgn Entsize
|
|
167
|
|
168 [1] 1 2 0x80480d4 0xd4 0x13 .interp
|
|
169 0 0 0x1 0
|
|
170
|
|
171 [2] 5 2 0x80480e8 0xe8 0x388 .hash
|
|
172 3 0 0x4 0x4
|
|
173
|
|
174 [3] 11 2 0x8048470 0x470 0x7f0 .dynsym
|
|
175 4 1 0x4 0x10
|
|
176
|
|
177 [4] 3 2 0x8048c60 0xc60 0x3ad .dynstr
|
|
178 0 0 0x1 0
|
|
179
|
|
180 [5] 9 2 0x8049010 0x1010 0x338 .rel.plt
|
|
181 3 7 0x4 0x8
|
|
182
|
|
183 [6] 1 6 0x8049348 0x1348 0x3 .init
|
|
184 0 0 0x4 0
|
|
185
|
|
186 [7] 1 6 0x804934c 0x134c 0x680 .plt
|
|
187 0 0 0x4 0x4
|
|
188
|
|
189 [8] 1 6 0x80499cc 0x19cc 0x3c56f .text
|
|
190 0 0 0x4 0
|
|
191
|
|
192 [9] 1 6 0x8085f3c 0x3df3c 0x3 .fini
|
|
193 0 0 0x4 0
|
|
194
|
|
195 [10] 1 2 0x8085f40 0x3df40 0x69c .rodata
|
|
196 0 0 0x4 0
|
|
197
|
|
198 [11] 1 2 0x80865dc 0x3e5dc 0xd51 .rodata1
|
|
199 0 0 0x4 0
|
|
200
|
|
201 [12] 1 3 0x8088330 0x3f330 0x20afc .data
|
|
202 0 0 0x4 0
|
|
203
|
|
204 [13] 1 3 0x80a8e2c 0x5fe2c 0x89d .data1
|
|
205 0 0 0x4 0
|
|
206
|
|
207 [14] 1 3 0x80a96cc 0x606cc 0x1a8 .got
|
|
208 0 0 0x4 0x4
|
|
209
|
|
210 [15] 6 3 0x80a9874 0x60874 0x80 .dynamic
|
|
211 4 0 0x4 0x8
|
|
212
|
|
213 [16] 8 3 0x80c6800 0x7d800 0 .bss
|
|
214 0 0 0x4 0
|
|
215
|
|
216 [17] 2 0 0 0x7d800 0x9b90 .symtab
|
|
217 18 371 0x4 0x10
|
|
218
|
|
219 [18] 3 0 0 0x87390 0x8526 .strtab
|
|
220 0 0 0x1 0
|
|
221
|
|
222 [19] 3 0 0 0x8f8b6 0x93 .shstrtab
|
|
223 0 0 0x1 0
|
|
224
|
|
225 [20] 1 0 0 0x8f949 0x68b7 .comment
|
|
226 0 0 0x1 0
|
|
227
|
|
228 [21] 1 3 0x80a98f4 0x608f4 0x1cf0c .data
|
|
229 0 0 0x4 0
|
|
230
|
|
231 * This is an example of how the file header is changed. "Shoff" is
|
|
232 * the section header offset within the file. Since that table is
|
|
233 * after the new .data section, it is moved. "Shnum" is the number of
|
|
234 * sections, which we increment.
|
|
235 *
|
|
236 * "Phoff" is the file offset to the program header. "Phentsize" and
|
|
237 * "Shentsz" are the program and section header entries sizes respectively.
|
|
238 * These can be larger than the apparent struct sizes.
|
|
239
|
|
240 raid:/nfs/raid/src/dist-18.56/src> dump -f temacs
|
|
241
|
|
242 temacs:
|
|
243
|
|
244 **** ELF HEADER ****
|
|
245 Class Data Type Machine Version
|
|
246 Entry Phoff Shoff Flags Ehsize
|
|
247 Phentsize Phnum Shentsz Shnum Shstrndx
|
|
248
|
|
249 1 1 2 3 1
|
|
250 0x80499cc 0x34 0x792f4 0 0x34
|
|
251 0x20 5 0x28 21 19
|
|
252
|
|
253 raid:/nfs/raid/src/dist-18.56/src> dump -f xemacs
|
|
254
|
|
255 xemacs:
|
|
256
|
|
257 **** ELF HEADER ****
|
|
258 Class Data Type Machine Version
|
|
259 Entry Phoff Shoff Flags Ehsize
|
|
260 Phentsize Phnum Shentsz Shnum Shstrndx
|
|
261
|
|
262 1 1 2 3 1
|
|
263 0x80499cc 0x34 0x96200 0 0x34
|
|
264 0x20 5 0x28 22 19
|
|
265
|
|
266 * These are the program headers. "Offset" is the file offset to the
|
|
267 * segment. "Vaddr" is the memory load address. "Filesz" is the
|
|
268 * segment size as it appears in the file, and "Memsz" is the size in
|
|
269 * memory. Below, the third segment is the code and the fourth is the
|
|
270 * data: the difference between Filesz and Memsz is .bss
|
|
271
|
|
272 raid:/nfs/raid/src/dist-18.56/src> dump -o temacs
|
|
273
|
|
274 temacs:
|
|
275 ***** PROGRAM EXECUTION HEADER *****
|
|
276 Type Offset Vaddr Paddr
|
|
277 Filesz Memsz Flags Align
|
|
278
|
|
279 6 0x34 0x8048034 0
|
|
280 0xa0 0xa0 5 0
|
|
281
|
|
282 3 0xd4 0 0
|
|
283 0x13 0 4 0
|
|
284
|
|
285 1 0x34 0x8048034 0
|
|
286 0x3f2f9 0x3f2f9 5 0x1000
|
|
287
|
|
288 1 0x3f330 0x8088330 0
|
|
289 0x215c4 0x25a60 7 0x1000
|
|
290
|
|
291 2 0x60874 0x80a9874 0
|
|
292 0x80 0 7 0
|
|
293
|
|
294 raid:/nfs/raid/src/dist-18.56/src> dump -o xemacs
|
|
295
|
|
296 xemacs:
|
|
297 ***** PROGRAM EXECUTION HEADER *****
|
|
298 Type Offset Vaddr Paddr
|
|
299 Filesz Memsz Flags Align
|
|
300
|
|
301 6 0x34 0x8048034 0
|
|
302 0xa0 0xa0 5 0
|
|
303
|
|
304 3 0xd4 0 0
|
|
305 0x13 0 4 0
|
|
306
|
|
307 1 0x34 0x8048034 0
|
|
308 0x3f2f9 0x3f2f9 5 0x1000
|
|
309
|
|
310 1 0x3f330 0x8088330 0
|
|
311 0x3e4d0 0x3e4d0 7 0x1000
|
|
312
|
|
313 2 0x60874 0x80a9874 0
|
|
314 0x80 0 7 0
|
|
315
|
|
316
|
|
317 */
|
|
318
|
|
319 /* Modified by wtien@urbana.mcd.mot.com of Motorola Inc.
|
|
320 *
|
|
321 * The above mechanism does not work if the unexeced ELF file is being
|
|
322 * re-layout by other applications (such as `strip'). All the applications
|
|
323 * that re-layout the internal of ELF will layout all sections in ascending
|
|
324 * order of their file offsets. After the re-layout, the data2 section will
|
|
325 * still be the LAST section in the section header vector, but its file offset
|
|
326 * is now being pushed far away down, and causes part of it not to be mapped
|
|
327 * in (ie. not covered by the load segment entry in PHDR vector), therefore
|
|
328 * causes the new binary to fail.
|
|
329 *
|
|
330 * The solution is to modify the unexec algorithm to insert the new data2
|
|
331 * section header right before the new bss section header, so their file
|
|
332 * offsets will be in the ascending order. Since some of the section's (all
|
|
333 * sections AFTER the bss section) indexes are now changed, we also need to
|
|
334 * modify some fields to make them point to the right sections. This is done
|
|
335 * by macro PATCH_INDEX. All the fields that need to be patched are:
|
|
336 *
|
|
337 * 1. ELF header e_shstrndx field.
|
|
338 * 2. section header sh_link and sh_info field.
|
|
339 * 3. symbol table entry st_shndx field.
|
|
340 *
|
|
341 * The above example now should look like:
|
|
342
|
|
343 **** SECTION HEADER TABLE ****
|
|
344 [No] Type Flags Addr Offset Size Name
|
|
345 Link Info Adralgn Entsize
|
|
346
|
|
347 [1] 1 2 0x80480d4 0xd4 0x13 .interp
|
|
348 0 0 0x1 0
|
|
349
|
|
350 [2] 5 2 0x80480e8 0xe8 0x388 .hash
|
|
351 3 0 0x4 0x4
|
|
352
|
|
353 [3] 11 2 0x8048470 0x470 0x7f0 .dynsym
|
|
354 4 1 0x4 0x10
|
|
355
|
|
356 [4] 3 2 0x8048c60 0xc60 0x3ad .dynstr
|
|
357 0 0 0x1 0
|
|
358
|
|
359 [5] 9 2 0x8049010 0x1010 0x338 .rel.plt
|
|
360 3 7 0x4 0x8
|
|
361
|
|
362 [6] 1 6 0x8049348 0x1348 0x3 .init
|
|
363 0 0 0x4 0
|
|
364
|
|
365 [7] 1 6 0x804934c 0x134c 0x680 .plt
|
|
366 0 0 0x4 0x4
|
|
367
|
|
368 [8] 1 6 0x80499cc 0x19cc 0x3c56f .text
|
|
369 0 0 0x4 0
|
|
370
|
|
371 [9] 1 6 0x8085f3c 0x3df3c 0x3 .fini
|
|
372 0 0 0x4 0
|
|
373
|
|
374 [10] 1 2 0x8085f40 0x3df40 0x69c .rodata
|
|
375 0 0 0x4 0
|
|
376
|
|
377 [11] 1 2 0x80865dc 0x3e5dc 0xd51 .rodata1
|
|
378 0 0 0x4 0
|
|
379
|
|
380 [12] 1 3 0x8088330 0x3f330 0x20afc .data
|
|
381 0 0 0x4 0
|
|
382
|
|
383 [13] 1 3 0x80a8e2c 0x5fe2c 0x89d .data1
|
|
384 0 0 0x4 0
|
|
385
|
|
386 [14] 1 3 0x80a96cc 0x606cc 0x1a8 .got
|
|
387 0 0 0x4 0x4
|
|
388
|
|
389 [15] 6 3 0x80a9874 0x60874 0x80 .dynamic
|
|
390 4 0 0x4 0x8
|
|
391
|
|
392 [16] 1 3 0x80a98f4 0x608f4 0x1cf0c .data
|
|
393 0 0 0x4 0
|
|
394
|
|
395 [17] 8 3 0x80c6800 0x7d800 0 .bss
|
|
396 0 0 0x4 0
|
|
397
|
|
398 [18] 2 0 0 0x7d800 0x9b90 .symtab
|
|
399 19 371 0x4 0x10
|
|
400
|
|
401 [19] 3 0 0 0x87390 0x8526 .strtab
|
|
402 0 0 0x1 0
|
|
403
|
|
404 [20] 3 0 0 0x8f8b6 0x93 .shstrtab
|
|
405 0 0 0x1 0
|
|
406
|
|
407 [21] 1 0 0 0x8f949 0x68b7 .comment
|
|
408 0 0 0x1 0
|
|
409
|
|
410 */
|
|
411
|
|
412 #include <sys/types.h>
|
|
413 #include <stdio.h>
|
|
414 #include <sys/stat.h>
|
|
415 #include <memory.h>
|
|
416 #include <string.h>
|
|
417 #include <errno.h>
|
|
418 #include <unistd.h>
|
|
419 #include <fcntl.h>
|
|
420 #include <elf.h>
|
|
421 #include <sys/mman.h>
|
|
422
|
259
|
423 #if __GLIBC__ - 0 >= 2
|
255
|
424 # include <link.h> /* get ElfW etc */
|
|
425 #endif
|
|
426
|
|
427 #ifndef ElfW
|
|
428 # ifdef __STDC__
|
|
429 # define ElfW(type) Elf32_##type
|
|
430 # else
|
|
431 # define ElfW(type) Elf32_/**/type
|
|
432 # endif
|
|
433 #endif
|
|
434
|
0
|
435 #ifndef emacs
|
|
436 #define fatal(a, b, c) fprintf (stderr, a, b, c), exit (1)
|
|
437 #else
|
|
438 #include <config.h>
|
|
439 extern void fatal (char *, ...);
|
|
440 #endif
|
|
441
|
|
442 #ifndef ELF_BSS_SECTION_NAME
|
|
443 #define ELF_BSS_SECTION_NAME ".bss"
|
|
444 #endif
|
|
445
|
|
446 /* Get the address of a particular section or program header entry,
|
|
447 * accounting for the size of the entries.
|
|
448 */
|
|
449 /*
|
|
450 On PPC Reference Platform running Solaris 2.5.1
|
|
451 the plt section is also of type NOBI like the bss section.
|
|
452 (not really stored) and therefore sections after the bss
|
|
453 section start at the plt offset. The plt section is always
|
|
454 the one just before the bss section.
|
|
455 Thus, we modify the test from
|
|
456 if (NEW_SECTION_H (nn).sh_offset >= new_data2_offset)
|
|
457 to
|
|
458 if (NEW_SECTION_H (nn).sh_offset >=
|
|
459 OLD_SECTION_H (old_bss_index-1).sh_offset)
|
|
460 This is just a hack. We should put the new data section
|
|
461 before the .plt section.
|
|
462 And we should not have this routine at all but use
|
|
463 the libelf library to read the old file and create the new
|
|
464 file.
|
|
465 The changed code is minimal and depends on prep set in m/prep.h
|
|
466 Erik Deumens
|
|
467 Quantum Theory Project
|
|
468 University of Florida
|
|
469 deumens@qtp.ufl.edu
|
|
470 Apr 23, 1996
|
|
471 */
|
|
472
|
|
473 #define OLD_SECTION_H(n) \
|
255
|
474 (*(ElfW(Shdr) *) ((byte *) old_section_h + old_file_h->e_shentsize * (n)))
|
0
|
475 #define NEW_SECTION_H(n) \
|
255
|
476 (*(ElfW(Shdr) *) ((byte *) new_section_h + new_file_h->e_shentsize * (n)))
|
0
|
477 #define OLD_PROGRAM_H(n) \
|
255
|
478 (*(ElfW(Phdr) *) ((byte *) old_program_h + old_file_h->e_phentsize * (n)))
|
0
|
479 #define NEW_PROGRAM_H(n) \
|
255
|
480 (*(ElfW(Phdr) *) ((byte *) new_program_h + new_file_h->e_phentsize * (n)))
|
0
|
481
|
|
482 #define PATCH_INDEX(n) \
|
|
483 do { \
|
|
484 if ((int) (n) >= old_bss_index) \
|
|
485 (n)++; } while (0)
|
|
486 typedef unsigned char byte;
|
|
487
|
|
488 /* Round X up to a multiple of Y. */
|
|
489
|
|
490 static int
|
|
491 round_up (int x, int y)
|
|
492 {
|
|
493 int rem = x % y;
|
|
494 if (rem == 0)
|
|
495 return x;
|
|
496 return x - rem + y;
|
|
497 }
|
|
498
|
|
499 /* ****************************************************************
|
|
500 * unexec
|
|
501 *
|
|
502 * driving logic.
|
|
503 *
|
|
504 * In ELF, this works by replacing the old .bss section with a new
|
|
505 * .data section, and inserting an empty .bss immediately afterwards.
|
|
506 *
|
|
507 */
|
|
508 void unexec (char *new_name, char *old_name, unsigned int data_start,
|
|
509 unsigned int bss_start, unsigned int entry_address);
|
|
510 void
|
|
511 unexec (char *new_name, char *old_name, unsigned int data_start,
|
|
512 unsigned int bss_start, unsigned int entry_address)
|
|
513 {
|
|
514 int new_file, old_file, new_file_size;
|
|
515
|
|
516 /* Pointers to the base of the image of the two files. */
|
|
517 caddr_t old_base, new_base;
|
|
518
|
|
519 /* Pointers to the file, program and section headers for the old and new
|
|
520 * files.
|
|
521 */
|
255
|
522 ElfW(Ehdr) *old_file_h, *new_file_h;
|
|
523 ElfW(Phdr) *old_program_h, *new_program_h;
|
|
524 ElfW(Shdr) *old_section_h, *new_section_h;
|
0
|
525
|
|
526 /* Point to the section name table in the old file */
|
|
527 char *old_section_names;
|
|
528
|
255
|
529 ElfW(Addr) old_bss_addr, new_bss_addr;
|
|
530 ElfW(Word) old_bss_size, new_data2_size;
|
|
531 ElfW(Off) new_data2_offset;
|
|
532 ElfW(Addr) new_data2_addr;
|
0
|
533
|
|
534 int n, nn, old_bss_index, old_data_index;
|
|
535 struct stat stat_buf;
|
|
536
|
|
537 /* Open the old file & map it into the address space. */
|
|
538
|
|
539 old_file = open (old_name, O_RDONLY);
|
|
540
|
|
541 if (old_file < 0)
|
|
542 fatal ("Can't open %s for reading: errno %d\n", old_name, errno);
|
|
543
|
|
544 if (fstat (old_file, &stat_buf) == -1)
|
|
545 fatal ("Can't fstat (%s): errno %d\n", old_name, errno);
|
|
546
|
|
547 old_base = mmap (0, stat_buf.st_size, PROT_READ, MAP_SHARED, old_file, 0);
|
|
548
|
|
549 if (old_base == (caddr_t) -1)
|
|
550 fatal ("Can't mmap (%s): errno %d\n", old_name, errno);
|
|
551
|
|
552 #ifdef DEBUG
|
|
553 fprintf (stderr, "mmap (%s, %x) -> %x\n", old_name, stat_buf.st_size,
|
|
554 old_base);
|
|
555 #endif
|
|
556
|
|
557 /* Get pointers to headers & section names */
|
|
558
|
255
|
559 old_file_h = (ElfW(Ehdr) *) old_base;
|
|
560 old_program_h = (ElfW(Phdr) *) ((byte *) old_base + old_file_h->e_phoff);
|
|
561 old_section_h = (ElfW(Shdr) *) ((byte *) old_base + old_file_h->e_shoff);
|
0
|
562 old_section_names = (char *) old_base
|
|
563 + OLD_SECTION_H (old_file_h->e_shstrndx).sh_offset;
|
|
564
|
|
565 /* Find the old .bss section. Figure out parameters of the new
|
|
566 * data2 and bss sections.
|
|
567 */
|
|
568
|
|
569 for (old_bss_index = 1; old_bss_index < (int) old_file_h->e_shnum;
|
|
570 old_bss_index++)
|
|
571 {
|
|
572 #ifdef DEBUG
|
|
573 fprintf (stderr, "Looking for .bss - found %s\n",
|
|
574 old_section_names + OLD_SECTION_H (old_bss_index).sh_name);
|
|
575 #endif
|
|
576 if (!strcmp (old_section_names + OLD_SECTION_H (old_bss_index).sh_name,
|
|
577 ELF_BSS_SECTION_NAME))
|
|
578 break;
|
|
579 }
|
|
580 if (old_bss_index == old_file_h->e_shnum)
|
|
581 fatal ("Can't find .bss in %s.\n", old_name, 0);
|
|
582
|
|
583 old_bss_addr = OLD_SECTION_H (old_bss_index).sh_addr;
|
|
584 old_bss_size = OLD_SECTION_H (old_bss_index).sh_size;
|
255
|
585 #if defined (emacs) || !defined (DEBUG)
|
|
586 new_bss_addr = (ElfW(Addr)) sbrk (0);
|
0
|
587 #else
|
|
588 new_bss_addr = old_bss_addr + old_bss_size + 0x1234;
|
|
589 #endif
|
|
590 new_data2_addr = old_bss_addr;
|
|
591 new_data2_size = new_bss_addr - old_bss_addr;
|
|
592 new_data2_offset = OLD_SECTION_H (old_bss_index).sh_offset;
|
|
593
|
|
594 #ifdef DEBUG
|
|
595 fprintf (stderr, "old_bss_index %d\n", old_bss_index);
|
|
596 fprintf (stderr, "old_bss_addr %x\n", old_bss_addr);
|
|
597 fprintf (stderr, "old_bss_size %x\n", old_bss_size);
|
|
598 fprintf (stderr, "new_bss_addr %x\n", new_bss_addr);
|
|
599 fprintf (stderr, "new_data2_addr %x\n", new_data2_addr);
|
|
600 fprintf (stderr, "new_data2_size %x\n", new_data2_size);
|
|
601 fprintf (stderr, "new_data2_offset %x\n", new_data2_offset);
|
|
602 #endif
|
|
603
|
|
604 if ((unsigned) new_bss_addr < (unsigned) old_bss_addr + old_bss_size)
|
|
605 fatal (".bss shrank when undumping???\n", 0, 0);
|
|
606
|
|
607 /* Set the output file to the right size and mmap it. Set
|
|
608 * pointers to various interesting objects. stat_buf still has
|
|
609 * old_file data.
|
|
610 */
|
|
611
|
|
612 new_file = open (new_name, O_RDWR | O_CREAT, 0666);
|
|
613 if (new_file < 0)
|
|
614 fatal ("Can't creat (%s): errno %d\n", new_name, errno);
|
|
615
|
|
616 new_file_size = stat_buf.st_size + old_file_h->e_shentsize + new_data2_size;
|
|
617
|
|
618 if (ftruncate (new_file, new_file_size))
|
|
619 fatal ("Can't ftruncate (%s): errno %d\n", new_name, errno);
|
|
620
|
|
621 #ifdef UNEXEC_USE_MAP_PRIVATE
|
|
622 new_base = mmap (0, new_file_size, PROT_READ | PROT_WRITE, MAP_PRIVATE,
|
|
623 new_file, 0);
|
|
624 #else
|
|
625 new_base = mmap (0, new_file_size, PROT_READ | PROT_WRITE, MAP_SHARED,
|
|
626 new_file, 0);
|
|
627 #endif
|
|
628
|
|
629 if (new_base == (caddr_t) -1)
|
|
630 fatal ("Can't mmap (%s): errno %d\n", new_name, errno);
|
|
631
|
255
|
632 new_file_h = (ElfW(Ehdr) *) new_base;
|
|
633 new_program_h = (ElfW(Phdr) *) ((byte *) new_base + old_file_h->e_phoff);
|
|
634 new_section_h = (ElfW(Shdr) *)
|
0
|
635 ((byte *) new_base + old_file_h->e_shoff + new_data2_size);
|
|
636
|
|
637 /* Make our new file, program and section headers as copies of the
|
|
638 * originals.
|
|
639 */
|
|
640
|
|
641 memcpy (new_file_h, old_file_h, old_file_h->e_ehsize);
|
|
642 memcpy (new_program_h, old_program_h,
|
|
643 old_file_h->e_phnum * old_file_h->e_phentsize);
|
|
644
|
|
645 /* Modify the e_shstrndx if necessary. */
|
|
646 PATCH_INDEX (new_file_h->e_shstrndx);
|
|
647
|
|
648 /* Fix up file header. We'll add one section. Section header is
|
|
649 * further away now.
|
|
650 */
|
|
651
|
|
652 new_file_h->e_shoff += new_data2_size;
|
|
653 new_file_h->e_shnum += 1;
|
|
654
|
|
655 #ifdef DEBUG
|
|
656 fprintf (stderr, "Old section offset %x\n", old_file_h->e_shoff);
|
|
657 fprintf (stderr, "Old section count %d\n", old_file_h->e_shnum);
|
|
658 fprintf (stderr, "New section offset %x\n", new_file_h->e_shoff);
|
|
659 fprintf (stderr, "New section count %d\n", new_file_h->e_shnum);
|
|
660 #endif
|
|
661
|
|
662 /* Fix up a new program header. Extend the writable data segment so
|
|
663 * that the bss area is covered too. Find that segment by looking
|
|
664 * for a segment that ends just before the .bss area. Make sure
|
|
665 * that no segments are above the new .data2. Put a loop at the end
|
|
666 * to adjust the offset and address of any segment that is above
|
|
667 * data2, just in case we decide to allow this later.
|
|
668 */
|
|
669
|
|
670 for (n = new_file_h->e_phnum - 1; n >= 0; n--)
|
|
671 {
|
|
672 /* Compute maximum of all requirements for alignment of section. */
|
|
673 int alignment = (NEW_PROGRAM_H (n)).p_align;
|
|
674 if ((OLD_SECTION_H (old_bss_index)).sh_addralign > alignment)
|
|
675 alignment = OLD_SECTION_H (old_bss_index).sh_addralign;
|
|
676
|
|
677 #ifndef __mips /* ifndef added by jwz at suggestion of
|
|
678 r02kar@x4u2.desy.de (Karsten Kuenne) to avoid
|
|
679 "Program segment above .bss" when dumping.
|
|
680 */
|
|
681 if (NEW_PROGRAM_H (n).p_vaddr + NEW_PROGRAM_H (n).p_filesz > old_bss_addr)
|
|
682 fatal ("Program segment above .bss in %s\n", old_name, 0);
|
|
683 #endif /* __mips */
|
|
684
|
|
685 if (NEW_PROGRAM_H (n).p_type == PT_LOAD
|
|
686 && (round_up ((int) ((NEW_PROGRAM_H (n)).p_vaddr
|
|
687 + (NEW_PROGRAM_H (n)).p_filesz),
|
|
688 alignment)
|
|
689 == round_up ((int) old_bss_addr, alignment)))
|
|
690 break;
|
|
691 }
|
|
692 if (n < 0)
|
|
693 fatal ("Couldn't find segment next to .bss in %s\n", old_name, 0);
|
|
694
|
251
|
695 NEW_PROGRAM_H (n).p_filesz = new_bss_addr - NEW_PROGRAM_H (n).p_vaddr;
|
0
|
696 NEW_PROGRAM_H (n).p_memsz = NEW_PROGRAM_H (n).p_filesz;
|
|
697
|
|
698 #if 0 /* Maybe allow section after data2 - does this ever happen? */
|
|
699 for (n = new_file_h->e_phnum - 1; n >= 0; n--)
|
|
700 {
|
|
701 if (NEW_PROGRAM_H (n).p_vaddr
|
|
702 && NEW_PROGRAM_H (n).p_vaddr >= new_data2_addr)
|
|
703 NEW_PROGRAM_H (n).p_vaddr += new_data2_size - old_bss_size;
|
|
704
|
|
705 if (NEW_PROGRAM_H (n).p_offset >= new_data2_offset)
|
|
706 NEW_PROGRAM_H (n).p_offset += new_data2_size;
|
|
707 }
|
|
708 #endif
|
|
709
|
|
710 /* Fix up section headers based on new .data2 section. Any section
|
|
711 * whose offset or virtual address is after the new .data2 section
|
|
712 * gets its value adjusted. .bss size becomes zero and new address
|
|
713 * is set. data2 section header gets added by copying the existing
|
|
714 * .data header and modifying the offset, address and size.
|
|
715 */
|
|
716 for (old_data_index = 1; old_data_index < (int) old_file_h->e_shnum;
|
|
717 old_data_index++)
|
|
718 if (!strcmp (old_section_names + OLD_SECTION_H (old_data_index).sh_name,
|
|
719 ".data"))
|
|
720 break;
|
|
721 if (old_data_index == old_file_h->e_shnum)
|
|
722 fatal ("Can't find .data in %s.\n", old_name, 0);
|
|
723
|
|
724 /* Walk through all section headers, insert the new data2 section right
|
|
725 before the new bss section. */
|
|
726 for (n = 1, nn = 1; n < (int) old_file_h->e_shnum; n++, nn++)
|
|
727 {
|
|
728 caddr_t src;
|
|
729 /* If it is bss section, insert the new data2 section before it. */
|
|
730 if (n == old_bss_index)
|
|
731 {
|
|
732 /* Steal the data section header for this data2 section. */
|
|
733 memcpy (&NEW_SECTION_H (nn), &OLD_SECTION_H (old_data_index),
|
|
734 new_file_h->e_shentsize);
|
|
735
|
|
736 NEW_SECTION_H (nn).sh_addr = new_data2_addr;
|
|
737 NEW_SECTION_H (nn).sh_offset = new_data2_offset;
|
|
738 NEW_SECTION_H (nn).sh_size = new_data2_size;
|
|
739 /* Use the bss section's alignment. This will assure that the
|
|
740 new data2 section always be placed in the same spot as the old
|
|
741 bss section by any other application. */
|
|
742 NEW_SECTION_H (nn).sh_addralign = OLD_SECTION_H (n).sh_addralign;
|
|
743
|
|
744 /* Now copy over what we have in the memory now. */
|
|
745 memcpy (NEW_SECTION_H (nn).sh_offset + new_base,
|
|
746 (caddr_t) OLD_SECTION_H (n).sh_addr,
|
149
|
747 /* #### mrb: should be old_bss_size instead? */
|
0
|
748 new_data2_size);
|
|
749 nn++;
|
|
750 }
|
|
751
|
|
752 memcpy (&NEW_SECTION_H (nn), &OLD_SECTION_H (n),
|
|
753 old_file_h->e_shentsize);
|
|
754
|
|
755 /* The new bss section's size is zero, and its file offset and virtual
|
|
756 address should be off by NEW_DATA2_SIZE. */
|
|
757 if (n == old_bss_index)
|
|
758 {
|
|
759 /* NN should be `old_bss_index + 1' at this point. */
|
|
760 NEW_SECTION_H (nn).sh_offset += new_data2_size;
|
|
761 NEW_SECTION_H (nn).sh_addr += new_data2_size;
|
|
762 /* Let the new bss section address alignment be the same as the
|
|
763 section address alignment followed the old bss section, so
|
|
764 this section will be placed in exactly the same place. */
|
|
765 NEW_SECTION_H (nn).sh_addralign = OLD_SECTION_H (nn).sh_addralign;
|
|
766 NEW_SECTION_H (nn).sh_size = 0;
|
|
767 }
|
|
768 else
|
|
769 {
|
|
770 /* Any section that was original placed AFTER the bss
|
|
771 section should now be off by NEW_DATA2_SIZE. */
|
|
772 #ifdef SOLARIS_POWERPC
|
|
773 /* On PPC Reference Platform running Solaris 2.5.1
|
|
774 the plt section is also of type NOBI like the bss section.
|
|
775 (not really stored) and therefore sections after the bss
|
|
776 section start at the plt offset. The plt section is always
|
|
777 the one just before the bss section.
|
|
778 It would be better to put the new data section before
|
|
779 the .plt section, or use libelf instead.
|
|
780 Erik Deumens, deumens@qtp.ufl.edu. */
|
|
781 if (NEW_SECTION_H (nn).sh_offset
|
|
782 >= OLD_SECTION_H (old_bss_index-1).sh_offset)
|
|
783 NEW_SECTION_H (nn).sh_offset += new_data2_size;
|
|
784 #else
|
|
785 if (NEW_SECTION_H (nn).sh_offset >= new_data2_offset)
|
|
786 NEW_SECTION_H (nn).sh_offset += new_data2_size;
|
|
787 #endif
|
|
788 /* Any section that was originally placed after the section
|
|
789 header table should now be off by the size of one section
|
|
790 header table entry. */
|
|
791 if (NEW_SECTION_H (nn).sh_offset > new_file_h->e_shoff)
|
|
792 NEW_SECTION_H (nn).sh_offset += new_file_h->e_shentsize;
|
|
793 }
|
|
794
|
|
795 /* If any section hdr refers to the section after the new .data
|
|
796 section, make it refer to next one because we have inserted
|
|
797 a new section in between. */
|
|
798
|
|
799 PATCH_INDEX (NEW_SECTION_H (nn).sh_link);
|
|
800 /* For symbol tables, info is a symbol table index,
|
|
801 so don't change it. */
|
|
802 if (NEW_SECTION_H (nn).sh_type != SHT_SYMTAB
|
|
803 && NEW_SECTION_H (nn).sh_type != SHT_DYNSYM)
|
|
804 PATCH_INDEX (NEW_SECTION_H (nn).sh_info);
|
|
805
|
|
806 /* Now, start to copy the content of sections. */
|
|
807 if (NEW_SECTION_H (nn).sh_type == SHT_NULL
|
|
808 || NEW_SECTION_H (nn).sh_type == SHT_NOBITS)
|
|
809 continue;
|
|
810
|
|
811 /* Write out the sections. .data and .data1 (and data2, called
|
|
812 ".data" in the strings table) get copied from the current process
|
|
813 instead of the old file. */
|
247
|
814 #ifdef __powerpc__
|
|
815 /* The PowerPC has additional 'data' segments which need to be saved */
|
|
816 if (!strcmp (old_section_names + NEW_SECTION_H (n).sh_name, ".data") ||
|
|
817 !strcmp (old_section_names + NEW_SECTION_H (n).sh_name, ".data1") ||
|
|
818 !strcmp (old_section_names + NEW_SECTION_H (n).sh_name, ".sdata") ||
|
|
819 !strcmp (old_section_names + NEW_SECTION_H (n).sh_name, ".sdata1"))
|
|
820 #else
|
0
|
821 if (!strcmp (old_section_names + NEW_SECTION_H (n).sh_name, ".data")
|
|
822 || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name),
|
|
823 ".data1"))
|
247
|
824 #endif
|
0
|
825 src = (caddr_t) OLD_SECTION_H (n).sh_addr;
|
|
826 else
|
|
827 src = old_base + OLD_SECTION_H (n).sh_offset;
|
|
828
|
|
829 memcpy (NEW_SECTION_H (nn).sh_offset + new_base, src,
|
|
830 NEW_SECTION_H (nn).sh_size);
|
|
831
|
|
832 /* If it is the symbol table, its st_shndx field needs to be patched. */
|
|
833 if (NEW_SECTION_H (nn).sh_type == SHT_SYMTAB
|
|
834 || NEW_SECTION_H (nn).sh_type == SHT_DYNSYM)
|
|
835 {
|
255
|
836 ElfW(Shdr) *spt = &NEW_SECTION_H (nn);
|
0
|
837 unsigned int num = spt->sh_size / spt->sh_entsize;
|
255
|
838 ElfW(Sym) * sym = (ElfW(Sym) *) (NEW_SECTION_H (nn).sh_offset +
|
0
|
839 new_base);
|
|
840 for (; num--; sym++)
|
|
841 {
|
|
842 if ((sym->st_shndx == SHN_UNDEF)
|
|
843 || (sym->st_shndx == SHN_ABS)
|
|
844 || (sym->st_shndx == SHN_COMMON))
|
|
845 continue;
|
|
846
|
|
847 PATCH_INDEX (sym->st_shndx);
|
|
848 }
|
|
849 }
|
|
850 }
|
|
851
|
|
852 /* Update the symbol values of _edata and _end. */
|
|
853 for (n = new_file_h->e_shnum - 1; n; n--)
|
|
854 {
|
|
855 byte *symnames;
|
255
|
856 ElfW(Sym) *symp, *symendp;
|
0
|
857
|
|
858 if (NEW_SECTION_H (n).sh_type != SHT_DYNSYM
|
|
859 && NEW_SECTION_H (n).sh_type != SHT_SYMTAB)
|
|
860 continue;
|
|
861
|
|
862 symnames = ((byte *) new_base
|
|
863 + NEW_SECTION_H (NEW_SECTION_H (n).sh_link).sh_offset);
|
255
|
864 symp = (ElfW(Sym) *) (NEW_SECTION_H (n).sh_offset + new_base);
|
|
865 symendp = (ElfW(Sym) *) ((byte *)symp + NEW_SECTION_H (n).sh_size);
|
0
|
866
|
|
867 for (; symp < symendp; symp ++)
|
|
868 if (strcmp ((char *) (symnames + symp->st_name), "_end") == 0
|
|
869 || strcmp ((char *) (symnames + symp->st_name), "_edata") == 0)
|
|
870 memcpy (&symp->st_value, &new_bss_addr, sizeof (new_bss_addr));
|
|
871 }
|
|
872
|
|
873 /* This loop seeks out relocation sections for the data section, so
|
|
874 that it can undo relocations performed by the runtime linker. */
|
|
875 for (n = new_file_h->e_shnum - 1; n; n--)
|
|
876 {
|
255
|
877 ElfW(Shdr) section = NEW_SECTION_H (n);
|
0
|
878 switch (section.sh_type) {
|
|
879 default:
|
|
880 break;
|
|
881 case SHT_REL:
|
|
882 case SHT_RELA:
|
|
883 /* This code handles two different size structs, but there should
|
|
884 be no harm in that provided that r_offset is always the first
|
|
885 member. */
|
|
886 nn = section.sh_info;
|
247
|
887 #ifdef __powerpc__
|
|
888 /* The PowerPC has additional 'data' segments which need to be saved */
|
|
889 if (!strcmp (old_section_names + NEW_SECTION_H (n).sh_name, ".data") ||
|
|
890 !strcmp (old_section_names + NEW_SECTION_H (n).sh_name, ".data1") ||
|
|
891 !strcmp (old_section_names + NEW_SECTION_H (n).sh_name, ".sdata") ||
|
|
892 !strcmp (old_section_names + NEW_SECTION_H (n).sh_name, ".sdata1"))
|
|
893 #else
|
0
|
894 if (!strcmp (old_section_names + NEW_SECTION_H (nn).sh_name, ".data")
|
|
895 || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name),
|
|
896 ".data1"))
|
247
|
897 #endif
|
0
|
898 {
|
255
|
899 ElfW(Addr) offset = NEW_SECTION_H (nn).sh_addr -
|
0
|
900 NEW_SECTION_H (nn).sh_offset;
|
|
901 caddr_t reloc = old_base + section.sh_offset, end;
|
|
902 for (end = reloc + section.sh_size; reloc < end;
|
|
903 reloc += section.sh_entsize)
|
|
904 {
|
255
|
905 ElfW(Addr) addr = ((ElfW(Rel) *) reloc)->r_offset - offset;
|
|
906 memcpy (new_base + addr, old_base + addr, sizeof(ElfW(Addr)));
|
0
|
907 }
|
|
908 }
|
|
909 break;
|
|
910 }
|
|
911 }
|
|
912
|
|
913 #ifdef UNEXEC_USE_MAP_PRIVATE
|
|
914 if (lseek (new_file, 0, SEEK_SET) == -1)
|
|
915 fatal ("Can't rewind (%s): errno %d\n", new_name, errno);
|
|
916
|
|
917 if (write (new_file, new_base, new_file_size) != new_file_size)
|
|
918 fatal ("Can't write (%s): errno %d\n", new_name, errno);
|
|
919 #endif
|
|
920
|
|
921 /* Close the files and make the new file executable. */
|
|
922
|
|
923 if (close (old_file))
|
|
924 fatal ("Can't close (%s): errno %d\n", old_name, errno);
|
|
925
|
|
926 if (close (new_file))
|
|
927 fatal ("Can't close (%s): errno %d\n", new_name, errno);
|
|
928
|
|
929 if (stat (new_name, &stat_buf) == -1)
|
|
930 fatal ("Can't stat (%s): errno %d\n", new_name, errno);
|
|
931
|
|
932 n = umask (777);
|
|
933 umask (n);
|
|
934 stat_buf.st_mode |= 0111 & ~n;
|
|
935 if (chmod (new_name, stat_buf.st_mode) == -1)
|
|
936 fatal ("Can't chmod (%s): errno %d\n", new_name, errno);
|
|
937 }
|