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513dea0a RS |
1 | /* Copyright (C) 1985, 1986, 1987, 1988, 1990, 1992 |
2 | Free Software Foundation, Inc. | |
3 | ||
4 | This file is part of GNU Emacs. | |
5 | ||
6 | GNU Emacs is free software; you can redistribute it and/or modify | |
7 | it under the terms of the GNU General Public License as published by | |
8 | the Free Software Foundation; either version 2, or (at your option) | |
9 | any later version. | |
10 | ||
11 | GNU Emacs is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with GNU Emacs; see the file COPYING. If not, write to | |
18 | the Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
19 | Boston, MA 02111-1307, USA. | |
20 | ||
21 | In other words, you are welcome to use, share and improve this program. | |
22 | You are forbidden to forbid anyone else to use, share and improve | |
23 | what you give them. Help stamp out software-hoarding! */ | |
24 | ||
25 | ||
26 | /* | |
27 | * unexec.c - Convert a running program into an a.out file. | |
28 | * | |
29 | * Author: Spencer W. Thomas | |
30 | * Computer Science Dept. | |
31 | * University of Utah | |
32 | * Date: Tue Mar 2 1982 | |
33 | * Modified heavily since then. | |
34 | * | |
35 | * Synopsis: | |
36 | * unexec (new_name, 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 | ||
95 | raid:/nfs/raid/src/dist-18.56/src> dump -h temacs | |
96 | ||
97 | temacs: | |
98 | ||
99 | **** SECTION HEADER TABLE **** | |
100 | [No] Type Flags Addr Offset Size Name | |
101 | Link Info Adralgn Entsize | |
102 | ||
103 | [1] 1 2 0x80480d4 0xd4 0x13 .interp | |
104 | 0 0 0x1 0 | |
105 | ||
106 | [2] 5 2 0x80480e8 0xe8 0x388 .hash | |
107 | 3 0 0x4 0x4 | |
108 | ||
109 | [3] 11 2 0x8048470 0x470 0x7f0 .dynsym | |
110 | 4 1 0x4 0x10 | |
111 | ||
112 | [4] 3 2 0x8048c60 0xc60 0x3ad .dynstr | |
113 | 0 0 0x1 0 | |
114 | ||
115 | [5] 9 2 0x8049010 0x1010 0x338 .rel.plt | |
116 | 3 7 0x4 0x8 | |
117 | ||
118 | [6] 1 6 0x8049348 0x1348 0x3 .init | |
119 | 0 0 0x4 0 | |
120 | ||
121 | [7] 1 6 0x804934c 0x134c 0x680 .plt | |
122 | 0 0 0x4 0x4 | |
123 | ||
124 | [8] 1 6 0x80499cc 0x19cc 0x3c56f .text | |
125 | 0 0 0x4 0 | |
126 | ||
127 | [9] 1 6 0x8085f3c 0x3df3c 0x3 .fini | |
128 | 0 0 0x4 0 | |
129 | ||
130 | [10] 1 2 0x8085f40 0x3df40 0x69c .rodata | |
131 | 0 0 0x4 0 | |
132 | ||
133 | [11] 1 2 0x80865dc 0x3e5dc 0xd51 .rodata1 | |
134 | 0 0 0x4 0 | |
135 | ||
136 | [12] 1 3 0x8088330 0x3f330 0x20afc .data | |
137 | 0 0 0x4 0 | |
138 | ||
139 | [13] 1 3 0x80a8e2c 0x5fe2c 0x89d .data1 | |
140 | 0 0 0x4 0 | |
141 | ||
142 | [14] 1 3 0x80a96cc 0x606cc 0x1a8 .got | |
143 | 0 0 0x4 0x4 | |
144 | ||
145 | [15] 6 3 0x80a9874 0x60874 0x80 .dynamic | |
146 | 4 0 0x4 0x8 | |
147 | ||
148 | [16] 8 3 0x80a98f4 0x608f4 0x449c .bss | |
149 | 0 0 0x4 0 | |
150 | ||
151 | [17] 2 0 0 0x608f4 0x9b90 .symtab | |
152 | 18 371 0x4 0x10 | |
153 | ||
154 | [18] 3 0 0 0x6a484 0x8526 .strtab | |
155 | 0 0 0x1 0 | |
156 | ||
157 | [19] 3 0 0 0x729aa 0x93 .shstrtab | |
158 | 0 0 0x1 0 | |
159 | ||
160 | [20] 1 0 0 0x72a3d 0x68b7 .comment | |
161 | 0 0 0x1 0 | |
162 | ||
163 | raid:/nfs/raid/src/dist-18.56/src> dump -h xemacs | |
164 | ||
165 | xemacs: | |
166 | ||
167 | **** SECTION HEADER TABLE **** | |
168 | [No] Type Flags Addr Offset Size Name | |
169 | Link Info Adralgn Entsize | |
170 | ||
171 | [1] 1 2 0x80480d4 0xd4 0x13 .interp | |
172 | 0 0 0x1 0 | |
173 | ||
174 | [2] 5 2 0x80480e8 0xe8 0x388 .hash | |
175 | 3 0 0x4 0x4 | |
176 | ||
177 | [3] 11 2 0x8048470 0x470 0x7f0 .dynsym | |
178 | 4 1 0x4 0x10 | |
179 | ||
180 | [4] 3 2 0x8048c60 0xc60 0x3ad .dynstr | |
181 | 0 0 0x1 0 | |
182 | ||
183 | [5] 9 2 0x8049010 0x1010 0x338 .rel.plt | |
184 | 3 7 0x4 0x8 | |
185 | ||
186 | [6] 1 6 0x8049348 0x1348 0x3 .init | |
187 | 0 0 0x4 0 | |
188 | ||
189 | [7] 1 6 0x804934c 0x134c 0x680 .plt | |
190 | 0 0 0x4 0x4 | |
191 | ||
192 | [8] 1 6 0x80499cc 0x19cc 0x3c56f .text | |
193 | 0 0 0x4 0 | |
194 | ||
195 | [9] 1 6 0x8085f3c 0x3df3c 0x3 .fini | |
196 | 0 0 0x4 0 | |
197 | ||
198 | [10] 1 2 0x8085f40 0x3df40 0x69c .rodata | |
199 | 0 0 0x4 0 | |
200 | ||
201 | [11] 1 2 0x80865dc 0x3e5dc 0xd51 .rodata1 | |
202 | 0 0 0x4 0 | |
203 | ||
204 | [12] 1 3 0x8088330 0x3f330 0x20afc .data | |
205 | 0 0 0x4 0 | |
206 | ||
207 | [13] 1 3 0x80a8e2c 0x5fe2c 0x89d .data1 | |
208 | 0 0 0x4 0 | |
209 | ||
210 | [14] 1 3 0x80a96cc 0x606cc 0x1a8 .got | |
211 | 0 0 0x4 0x4 | |
212 | ||
213 | [15] 6 3 0x80a9874 0x60874 0x80 .dynamic | |
214 | 4 0 0x4 0x8 | |
215 | ||
216 | [16] 8 3 0x80c6800 0x7d800 0 .bss | |
217 | 0 0 0x4 0 | |
218 | ||
219 | [17] 2 0 0 0x7d800 0x9b90 .symtab | |
220 | 18 371 0x4 0x10 | |
221 | ||
222 | [18] 3 0 0 0x87390 0x8526 .strtab | |
223 | 0 0 0x1 0 | |
224 | ||
225 | [19] 3 0 0 0x8f8b6 0x93 .shstrtab | |
226 | 0 0 0x1 0 | |
227 | ||
228 | [20] 1 0 0 0x8f949 0x68b7 .comment | |
229 | 0 0 0x1 0 | |
230 | ||
231 | [21] 1 3 0x80a98f4 0x608f4 0x1cf0c .data | |
232 | 0 0 0x4 0 | |
233 | ||
234 | * This is an example of how the file header is changed. "Shoff" is | |
235 | * the section header offset within the file. Since that table is | |
236 | * after the new .data section, it is moved. "Shnum" is the number of | |
237 | * sections, which we increment. | |
238 | * | |
239 | * "Phoff" is the file offset to the program header. "Phentsize" and | |
240 | * "Shentsz" are the program and section header entries sizes respectively. | |
241 | * These can be larger than the apparent struct sizes. | |
242 | ||
243 | raid:/nfs/raid/src/dist-18.56/src> dump -f temacs | |
244 | ||
245 | temacs: | |
246 | ||
247 | **** ELF HEADER **** | |
248 | Class Data Type Machine Version | |
249 | Entry Phoff Shoff Flags Ehsize | |
250 | Phentsize Phnum Shentsz Shnum Shstrndx | |
251 | ||
252 | 1 1 2 3 1 | |
253 | 0x80499cc 0x34 0x792f4 0 0x34 | |
254 | 0x20 5 0x28 21 19 | |
255 | ||
256 | raid:/nfs/raid/src/dist-18.56/src> dump -f xemacs | |
257 | ||
258 | xemacs: | |
259 | ||
260 | **** ELF HEADER **** | |
261 | Class Data Type Machine Version | |
262 | Entry Phoff Shoff Flags Ehsize | |
263 | Phentsize Phnum Shentsz Shnum Shstrndx | |
264 | ||
265 | 1 1 2 3 1 | |
266 | 0x80499cc 0x34 0x96200 0 0x34 | |
267 | 0x20 5 0x28 22 19 | |
268 | ||
269 | * These are the program headers. "Offset" is the file offset to the | |
270 | * segment. "Vaddr" is the memory load address. "Filesz" is the | |
271 | * segment size as it appears in the file, and "Memsz" is the size in | |
272 | * memory. Below, the third segment is the code and the fourth is the | |
273 | * data: the difference between Filesz and Memsz is .bss | |
274 | ||
275 | raid:/nfs/raid/src/dist-18.56/src> dump -o temacs | |
276 | ||
277 | temacs: | |
278 | ***** PROGRAM EXECUTION HEADER ***** | |
279 | Type Offset Vaddr Paddr | |
280 | Filesz Memsz Flags Align | |
281 | ||
282 | 6 0x34 0x8048034 0 | |
283 | 0xa0 0xa0 5 0 | |
284 | ||
285 | 3 0xd4 0 0 | |
286 | 0x13 0 4 0 | |
287 | ||
288 | 1 0x34 0x8048034 0 | |
289 | 0x3f2f9 0x3f2f9 5 0x1000 | |
290 | ||
291 | 1 0x3f330 0x8088330 0 | |
292 | 0x215c4 0x25a60 7 0x1000 | |
293 | ||
294 | 2 0x60874 0x80a9874 0 | |
295 | 0x80 0 7 0 | |
296 | ||
297 | raid:/nfs/raid/src/dist-18.56/src> dump -o xemacs | |
298 | ||
299 | xemacs: | |
300 | ***** PROGRAM EXECUTION HEADER ***** | |
301 | Type Offset Vaddr Paddr | |
302 | Filesz Memsz Flags Align | |
303 | ||
304 | 6 0x34 0x8048034 0 | |
305 | 0xa0 0xa0 5 0 | |
306 | ||
307 | 3 0xd4 0 0 | |
308 | 0x13 0 4 0 | |
309 | ||
310 | 1 0x34 0x8048034 0 | |
311 | 0x3f2f9 0x3f2f9 5 0x1000 | |
312 | ||
313 | 1 0x3f330 0x8088330 0 | |
314 | 0x3e4d0 0x3e4d0 7 0x1000 | |
315 | ||
316 | 2 0x60874 0x80a9874 0 | |
317 | 0x80 0 7 0 | |
318 | ||
319 | ||
320 | */ | |
321 | \f | |
322 | /* Modified by wtien@urbana.mcd.mot.com of Motorola Inc. | |
323 | * | |
324 | * The above mechanism does not work if the unexeced ELF file is being | |
325 | * re-layout by other applications (such as `strip'). All the applications | |
326 | * that re-layout the internal of ELF will layout all sections in ascending | |
327 | * order of their file offsets. After the re-layout, the data2 section will | |
328 | * still be the LAST section in the section header vector, but its file offset | |
329 | * is now being pushed far away down, and causes part of it not to be mapped | |
330 | * in (ie. not covered by the load segment entry in PHDR vector), therefore | |
331 | * causes the new binary to fail. | |
332 | * | |
333 | * The solution is to modify the unexec algorithm to insert the new data2 | |
334 | * section header right before the new bss section header, so their file | |
335 | * offsets will be in the ascending order. Since some of the section's (all | |
336 | * sections AFTER the bss section) indexes are now changed, we also need to | |
337 | * modify some fields to make them point to the right sections. This is done | |
338 | * by macro PATCH_INDEX. All the fields that need to be patched are: | |
339 | * | |
340 | * 1. ELF header e_shstrndx field. | |
341 | * 2. section header sh_link and sh_info field. | |
342 | * 3. symbol table entry st_shndx field. | |
343 | * | |
344 | * The above example now should look like: | |
345 | ||
346 | **** SECTION HEADER TABLE **** | |
347 | [No] Type Flags Addr Offset Size Name | |
348 | Link Info Adralgn Entsize | |
349 | ||
350 | [1] 1 2 0x80480d4 0xd4 0x13 .interp | |
351 | 0 0 0x1 0 | |
352 | ||
353 | [2] 5 2 0x80480e8 0xe8 0x388 .hash | |
354 | 3 0 0x4 0x4 | |
355 | ||
356 | [3] 11 2 0x8048470 0x470 0x7f0 .dynsym | |
357 | 4 1 0x4 0x10 | |
358 | ||
359 | [4] 3 2 0x8048c60 0xc60 0x3ad .dynstr | |
360 | 0 0 0x1 0 | |
361 | ||
362 | [5] 9 2 0x8049010 0x1010 0x338 .rel.plt | |
363 | 3 7 0x4 0x8 | |
364 | ||
365 | [6] 1 6 0x8049348 0x1348 0x3 .init | |
366 | 0 0 0x4 0 | |
367 | ||
368 | [7] 1 6 0x804934c 0x134c 0x680 .plt | |
369 | 0 0 0x4 0x4 | |
370 | ||
371 | [8] 1 6 0x80499cc 0x19cc 0x3c56f .text | |
372 | 0 0 0x4 0 | |
373 | ||
374 | [9] 1 6 0x8085f3c 0x3df3c 0x3 .fini | |
375 | 0 0 0x4 0 | |
376 | ||
377 | [10] 1 2 0x8085f40 0x3df40 0x69c .rodata | |
378 | 0 0 0x4 0 | |
379 | ||
380 | [11] 1 2 0x80865dc 0x3e5dc 0xd51 .rodata1 | |
381 | 0 0 0x4 0 | |
382 | ||
383 | [12] 1 3 0x8088330 0x3f330 0x20afc .data | |
384 | 0 0 0x4 0 | |
385 | ||
386 | [13] 1 3 0x80a8e2c 0x5fe2c 0x89d .data1 | |
387 | 0 0 0x4 0 | |
388 | ||
389 | [14] 1 3 0x80a96cc 0x606cc 0x1a8 .got | |
390 | 0 0 0x4 0x4 | |
391 | ||
392 | [15] 6 3 0x80a9874 0x60874 0x80 .dynamic | |
393 | 4 0 0x4 0x8 | |
394 | ||
395 | [16] 1 3 0x80a98f4 0x608f4 0x1cf0c .data | |
396 | 0 0 0x4 0 | |
397 | ||
398 | [17] 8 3 0x80c6800 0x7d800 0 .bss | |
399 | 0 0 0x4 0 | |
400 | ||
401 | [18] 2 0 0 0x7d800 0x9b90 .symtab | |
402 | 19 371 0x4 0x10 | |
403 | ||
404 | [19] 3 0 0 0x87390 0x8526 .strtab | |
405 | 0 0 0x1 0 | |
406 | ||
407 | [20] 3 0 0 0x8f8b6 0x93 .shstrtab | |
408 | 0 0 0x1 0 | |
409 | ||
410 | [21] 1 0 0 0x8f949 0x68b7 .comment | |
411 | 0 0 0x1 0 | |
412 | ||
413 | */ | |
414 | \f | |
415 | #include <sys/types.h> | |
416 | #include <stdio.h> | |
417 | #include <sys/stat.h> | |
418 | #include <memory.h> | |
419 | #include <string.h> | |
420 | #include <errno.h> | |
421 | #include <unistd.h> | |
422 | #include <fcntl.h> | |
423 | #include <elf.h> | |
424 | #include <sys/mman.h> | |
425 | ||
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 | ||
442 | #ifndef emacs | |
443 | #define fatal(a, b, c) fprintf (stderr, a, b, c), exit (1) | |
444 | #else | |
445 | #include <config.h> | |
446 | extern void fatal (char *, ...); | |
447 | #endif | |
448 | ||
449 | #ifndef ELF_BSS_SECTION_NAME | |
450 | #define ELF_BSS_SECTION_NAME ".bss" | |
451 | #endif | |
452 | ||
453 | /* Get the address of a particular section or program header entry, | |
454 | * accounting for the size of the entries. | |
455 | */ | |
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 | */ | |
479 | ||
480 | #define OLD_SECTION_H(n) \ | |
481 | (*(ElfW(Shdr) *) ((byte *) old_section_h + old_file_h->e_shentsize * (n))) | |
482 | #define NEW_SECTION_H(n) \ | |
483 | (*(ElfW(Shdr) *) ((byte *) new_section_h + new_file_h->e_shentsize * (n))) | |
484 | #define OLD_PROGRAM_H(n) \ | |
485 | (*(ElfW(Phdr) *) ((byte *) old_program_h + old_file_h->e_phentsize * (n))) | |
486 | #define NEW_PROGRAM_H(n) \ | |
487 | (*(ElfW(Phdr) *) ((byte *) new_program_h + new_file_h->e_phentsize * (n))) | |
488 | ||
489 | #define PATCH_INDEX(n) \ | |
490 | do { \ | |
491 | if ((int) (n) >= old_bss_index) \ | |
492 | (n)++; } while (0) | |
493 | typedef unsigned char byte; | |
494 | ||
495 | /* Round X up to a multiple of Y. */ | |
496 | ||
497 | int | |
498 | round_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 | ||
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 | */ | |
516 | void | |
517 | unexec (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 | { | |
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 | */ | |
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; | |
532 | ||
533 | /* Point to the section name table in the old file */ | |
534 | char *old_section_names; | |
535 | ||
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; | |
540 | ||
541 | int n, nn, old_bss_index, old_data_index, new_data2_index; | |
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) | |
552 | fatal ("Can't fstat (%s): errno %d\n", old_name, errno); | |
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) | |
557 | fatal ("Can't mmap (%s): errno %d\n", old_name, errno); | |
558 | ||
559 | #ifdef DEBUG | |
560 | fprintf (stderr, "mmap (%s, %x) -> %x\n", old_name, stat_buf.st_size, | |
561 | old_base); | |
562 | #endif | |
563 | ||
564 | /* Get pointers to headers & section names */ | |
565 | ||
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); | |
569 | old_section_names = (char *) old_base | |
570 | + OLD_SECTION_H (old_file_h->e_shstrndx).sh_offset; | |
571 | ||
572 | /* Find the old .bss section. Figure out parameters of the new | |
573 | * data2 and bss sections. | |
574 | */ | |
575 | ||
576 | for (old_bss_index = 1; old_bss_index < (int) old_file_h->e_shnum; | |
577 | old_bss_index++) | |
578 | { | |
579 | #ifdef DEBUG | |
580 | fprintf (stderr, "Looking for .bss - found %s\n", | |
581 | old_section_names + OLD_SECTION_H (old_bss_index).sh_name); | |
582 | #endif | |
583 | if (!strcmp (old_section_names + OLD_SECTION_H (old_bss_index).sh_name, | |
584 | ELF_BSS_SECTION_NAME)) | |
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 | ||
590 | old_bss_addr = OLD_SECTION_H (old_bss_index).sh_addr; | |
591 | old_bss_size = OLD_SECTION_H (old_bss_index).sh_size; | |
592 | #if defined(emacs) || !defined(DEBUG) | |
593 | new_bss_addr = (ElfW(Addr)) sbrk (0); | |
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; | |
599 | new_data2_offset = OLD_SECTION_H (old_bss_index).sh_offset; | |
600 | ||
601 | #ifdef DEBUG | |
602 | fprintf (stderr, "old_bss_index %d\n", old_bss_index); | |
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); | |
609 | #endif | |
610 | ||
611 | if ((unsigned) new_bss_addr < (unsigned) old_bss_addr + old_bss_size) | |
612 | fatal (".bss shrank when undumping???\n", 0, 0); | |
613 | ||
614 | /* Set the output file to the right size and mmap it. Set | |
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) | |
621 | fatal ("Can't creat (%s): errno %d\n", new_name, errno); | |
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)) | |
626 | fatal ("Can't ftruncate (%s): errno %d\n", new_name, errno); | |
627 | ||
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 | |
632 | new_base = mmap (0, new_file_size, PROT_READ | PROT_WRITE, MAP_SHARED, | |
633 | new_file, 0); | |
634 | #endif | |
635 | ||
636 | if (new_base == (caddr_t) -1) | |
637 | fatal ("Can't mmap (%s): errno %d\n", new_name, errno); | |
638 | ||
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) *) | |
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); | |
651 | ||
652 | /* Modify the e_shstrndx if necessary. */ | |
653 | PATCH_INDEX (new_file_h->e_shstrndx); | |
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 | |
663 | fprintf (stderr, "Old section offset %x\n", old_file_h->e_shoff); | |
664 | fprintf (stderr, "Old section count %d\n", old_file_h->e_shnum); | |
665 | fprintf (stderr, "New section offset %x\n", new_file_h->e_shoff); | |
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 | { | |
679 | /* Compute maximum of all requirements for alignment of section. */ | |
680 | int alignment = (NEW_PROGRAM_H (n)).p_align; | |
681 | if ((OLD_SECTION_H (old_bss_index)).sh_addralign > alignment) | |
682 | alignment = OLD_SECTION_H (old_bss_index).sh_addralign; | |
683 | ||
684 | if (NEW_PROGRAM_H (n).p_vaddr + NEW_PROGRAM_H (n).p_filesz > old_bss_addr) | |
685 | fatal ("Program segment above .bss in %s\n", old_name, 0); | |
686 | ||
687 | if (NEW_PROGRAM_H (n).p_type == PT_LOAD | |
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))) | |
692 | break; | |
693 | } | |
694 | if (n < 0) | |
695 | fatal ("Couldn't find segment next to .bss in %s\n", old_name, 0); | |
696 | ||
697 | NEW_PROGRAM_H (n).p_filesz += new_data2_size; | |
698 | NEW_PROGRAM_H (n).p_memsz = NEW_PROGRAM_H (n).p_filesz; | |
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 | { | |
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; | |
706 | ||
707 | if (NEW_PROGRAM_H (n).p_offset >= new_data2_offset) | |
708 | NEW_PROGRAM_H (n).p_offset += new_data2_size; | |
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 | */ | |
718 | for (old_data_index = 1; old_data_index < (int) old_file_h->e_shnum; | |
719 | old_data_index++) | |
720 | if (!strcmp (old_section_names + OLD_SECTION_H (old_data_index).sh_name, | |
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 | ||
726 | /* Walk through all section headers, insert the new data2 section right | |
727 | before the new bss section. */ | |
728 | for (n = 1, nn = 1; n < (int) old_file_h->e_shnum; n++, nn++) | |
729 | { | |
730 | caddr_t src; | |
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. */ | |
735 | memcpy (&NEW_SECTION_H (nn), &OLD_SECTION_H (old_data_index), | |
736 | new_file_h->e_shentsize); | |
737 | ||
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; | |
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. */ | |
744 | NEW_SECTION_H (nn).sh_addralign = OLD_SECTION_H (n).sh_addralign; | |
745 | ||
746 | /* Now copy over what we have in the memory now. */ | |
747 | memcpy (NEW_SECTION_H (nn).sh_offset + new_base, | |
748 | (caddr_t) OLD_SECTION_H (n).sh_addr, | |
749 | new_data2_size); | |
750 | nn++; | |
751 | } | |
752 | ||
753 | memcpy (&NEW_SECTION_H (nn), &OLD_SECTION_H (n), | |
754 | old_file_h->e_shentsize); | |
755 | ||
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. */ | |
761 | NEW_SECTION_H (nn).sh_offset += new_data2_size; | |
762 | NEW_SECTION_H (nn).sh_addr += new_data2_size; | |
763 | /* Let the new bss section address alignment be the same as the | |
764 | section address alignment followed the old bss section, so | |
765 | this section will be placed in exactly the same place. */ | |
766 | NEW_SECTION_H (nn).sh_addralign = OLD_SECTION_H (nn).sh_addralign; | |
767 | NEW_SECTION_H (nn).sh_size = 0; | |
768 | } | |
769 | else | |
770 | { | |
771 | /* Any section that was original placed AFTER the bss | |
772 | section should now be off by NEW_DATA2_SIZE. */ | |
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 | |
786 | if (round_up (NEW_SECTION_H (nn).sh_offset, | |
787 | OLD_SECTION_H (old_bss_index).sh_addralign) | |
788 | >= new_data2_offset) | |
789 | NEW_SECTION_H (nn).sh_offset += new_data2_size; | |
790 | #endif | |
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 | ||
798 | /* If any section hdr refers to the section after the new .data | |
799 | section, make it refer to next one because we have inserted | |
800 | a new section in between. */ | |
801 | ||
802 | PATCH_INDEX (NEW_SECTION_H (nn).sh_link); | |
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. */ | |
810 | if (NEW_SECTION_H (nn).sh_type == SHT_NULL | |
811 | || NEW_SECTION_H (nn).sh_type == SHT_NOBITS) | |
812 | continue; | |
813 | ||
814 | /* Write out the sections. .data and .data1 (and data2, called | |
815 | ".data" in the strings table) get copied from the current process | |
816 | instead of the old file. */ | |
817 | if (!strcmp (old_section_names + NEW_SECTION_H (n).sh_name, ".data") | |
818 | || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name), | |
819 | ".data1")) | |
820 | src = (caddr_t) OLD_SECTION_H (n).sh_addr; | |
821 | else | |
822 | src = old_base + OLD_SECTION_H (n).sh_offset; | |
823 | ||
824 | memcpy (NEW_SECTION_H (nn).sh_offset + new_base, src, | |
825 | NEW_SECTION_H (nn).sh_size); | |
826 | ||
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 | ||
848 | /* If it is the symbol table, its st_shndx field needs to be patched. */ | |
849 | if (NEW_SECTION_H (nn).sh_type == SHT_SYMTAB | |
850 | || NEW_SECTION_H (nn).sh_type == SHT_DYNSYM) | |
851 | { | |
852 | ElfW(Shdr) *spt = &NEW_SECTION_H (nn); | |
853 | unsigned int num = spt->sh_size / spt->sh_entsize; | |
854 | ElfW(Sym) * sym = (ElfW(Sym) *) (NEW_SECTION_H (nn).sh_offset + | |
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; | |
862 | ||
863 | PATCH_INDEX (sym->st_shndx); | |
864 | } | |
865 | } | |
866 | } | |
867 | ||
868 | /* Update the symbol values of _edata and _end. */ | |
869 | for (n = new_file_h->e_shnum - 1; n; n--) | |
870 | { | |
871 | byte *symnames; | |
872 | ElfW(Sym) *symp, *symendp; | |
873 | ||
874 | if (NEW_SECTION_H (n).sh_type != SHT_DYNSYM | |
875 | && NEW_SECTION_H (n).sh_type != SHT_SYMTAB) | |
876 | continue; | |
877 | ||
878 | symnames = ((byte *) new_base | |
879 | + NEW_SECTION_H (NEW_SECTION_H (n).sh_link).sh_offset); | |
880 | symp = (ElfW(Sym) *) (NEW_SECTION_H (n).sh_offset + new_base); | |
881 | symendp = (ElfW(Sym) *) ((byte *)symp + NEW_SECTION_H (n).sh_size); | |
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 | ||
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 | { | |
893 | ElfW(Shdr) section = NEW_SECTION_H (n); | |
894 | switch (section.sh_type) { | |
895 | default: | |
896 | break; | |
897 | case SHT_REL: | |
898 | case SHT_RELA: | |
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. */ | |
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 | { | |
907 | ElfW(Addr) offset = NEW_SECTION_H (nn).sh_addr - | |
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 | { | |
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))); | |
922 | } | |
923 | } | |
924 | break; | |
925 | } | |
926 | } | |
927 | ||
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 | ||
936 | /* Close the files and make the new file executable. */ | |
937 | ||
938 | if (close (old_file)) | |
939 | fatal ("Can't close (%s): errno %d\n", old_name, errno); | |
940 | ||
941 | if (close (new_file)) | |
942 | fatal ("Can't close (%s): errno %d\n", new_name, errno); | |
943 | ||
944 | if (stat (new_name, &stat_buf) == -1) | |
945 | fatal ("Can't stat (%s): errno %d\n", new_name, errno); | |
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) | |
951 | fatal ("Can't chmod (%s): errno %d\n", new_name, errno); | |
952 | } |