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comparison src/unexelfsgi.c @ 371:cc15677e0335 r21-2b1

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Import from CVS: tag r21-2b1
author cvs
date Mon, 13 Aug 2007 11:03:08 +0200
parents a4f53d9b3154
children 7d59cb494b73
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370:bd866891f083 371:cc15677e0335
1 /* Copyright (C) 1985, 1986, 1987, 1988, 1990, 1992, 1999, 2000 1 /* Copyright (C) 1985, 1986, 1987, 1988, 1990, 1992
2 Free Software Foundation, Inc. 2 Free Software Foundation, Inc.
3 3
4 This file is part of XEmacs. 4 This file is part of XEmacs.
5 5
6 XEmacs is free software; you can redistribute it and/or modify it 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 7 under the terms of the GNU General Public License as published by the
8 the Free Software Foundation; either version 2, or (at your option) 8 Free Software Foundation; either version 2, or (at your option) any
9 any later version. 9 later version.
10 10
11 GNU Emacs is distributed in the hope that it will be useful, but 11 XEmacs is distributed in the hope that it will be useful, but WITHOUT
12 WITHOUT ANY WARRANTY; without even the implied warranty of 12 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 General Public License for more details. 14 for more details.
15 15
16 You should have received a copy of the GNU General Public License 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 the 17 along with XEmacs; see the file COPYING. If not, write to
18 Free Software Foundation, Inc., 59 Temple Place - Suite 330, 18 the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. 19 Boston, MA 02111-1307, USA. */
20 20
21 In other words, you are welcome to use, share and improve this 21 /* Synched up with: FSF 19.31. */
22 program. You are forbidden to forbid anyone else to use, share and
23 improve what you give them. Help stamp out software-hoarding! */
24 22
25 23
26 /* 24 /*
27 * unexec.c - Convert a running program into an a.out file. 25 * unexec.c - Convert a running program into an a.out file.
28 * 26 *
31 * University of Utah 29 * University of Utah
32 * Date: Tue Mar 2 1982 30 * Date: Tue Mar 2 1982
33 * Modified heavily since then. 31 * Modified heavily since then.
34 * 32 *
35 * Synopsis: 33 * Synopsis:
36 * void 34 * unexec (new_name, a_name, data_start, bss_start, entry_address)
37 * unexec (char *new_name, 35 * char *new_name, *a_name;
38 * char *old_name, 36 * unsigned data_start, bss_start, entry_address;
39 * uintptr_t data_start, 37 *
40 * uintptr_t bss_start, 38 * Takes a snapshot of the program and makes an a.out format file in the
41 * uintptr_t entry_address) 39 * file named by the string argument new_name.
42 * 40 * If a_name is non-NULL, the symbol table will be taken from the given file.
43 * The basic idea is that we start with an ELF file which contains 41 * On some machines, an existing a_name file is required.
44 * .bss (uninitialized global data) section which is normally not in 42 *
45 * the file. As we load lisp the variables, which were first set to 0, 43 * The boundaries within the a.out file may be adjusted with the data_start
46 * will change their values. We want to save those changed values into 44 * and bss_start arguments. Either or both may be given as 0 for defaults.
47 * another ELF file, which will become a new xemacs image. To do this, 45 *
48 * we need to change several structures in the ELF file. 46 * Data_start gives the boundary between the text segment and the data
49 * 47 * segment of the program. The text segment can contain shared, read-only
50 * First of all, we need to change the programm header which tells 48 * program code and literal data, while the data segment is always unshared
51 * the linker how to load stuff into memory so that data will come 49 * and unprotected. Data_start gives the lowest unprotected address.
52 * from the file and not from the /dev/zero. To do this, we find the 50 * The value you specify may be rounded down to a suitable boundary
53 * segment, which is marked as loadable (type PT_LOAD) and which 51 * as required by the machine you are using.
54 * covers the old .bss section. We will next change the filesz and 52 *
55 * memsz for that segment to extend over the new data section. 53 * Specifying zero for data_start means the boundary between text and data
56 * 54 * should not be the same as when the program was loaded.
57 * Next we have to make sure that section header for the stuff which 55 * If NO_REMAP is defined, the argument data_start is ignored and the
58 * used to be uninitialized is changed to be initialized and to come 56 * segment boundaries are never changed.
59 * from the file. To do this, we change the size and the type of the old 57 *
60 * .bss section (and all other section of the type SHT_NOBITS) to cover the 58 * Bss_start indicates how much of the data segment is to be saved in the
61 * new section and to be of type SHT_PROCBITS. 59 * a.out file and restored when the program is executed. It gives the lowest
62 * 60 * unsaved address, and is rounded up to a page boundary. The default when 0
63 * We also insert a new SHT_NOBITS section to keep some tools, which expect 61 * is given assumes that the entire data segment is to be stored, including
64 * .bss happy. 62 * the previous data and bss as well as any additional storage allocated with
65 * 63 * break (2).
66 * Finally we need to patch up some references to the section 64 *
67 * indexes since we change the order and undo the relocation info to 65 * The new file is set up to start at entry_address.
68 * be the same as it was "before" because we actually used the data 66 *
69 * from the memory which were changed by the run-time linker. 67 * If you make improvements I'd like to get them too.
68 * harpo!utah-cs!thomas, thomas@Utah-20
69 *
70 */
71
72 /* Even more heavily modified by james@bigtex.cactus.org of Dell Computer Co.
73 * ELF support added.
74 *
75 * Basic theory: the data space of the running process needs to be
76 * dumped to the output file. Normally we would just enlarge the size
77 * of .data, scooting everything down. But we can't do that in ELF,
78 * because there is often something between the .data space and the
79 * .bss space.
80 *
81 * In the temacs dump below, notice that the Global Offset Table
82 * (.got) and the Dynamic link data (.dynamic) come between .data1 and
83 * .bss. It does not work to overlap .data with these fields.
84 *
85 * The solution is to create a new .data segment. This segment is
86 * filled with data from the current process. Since the contents of
87 * various sections refer to sections by index, the new .data segment
88 * is made the last in the table to avoid changing any existing index.
89
90 * This is an example of how the section headers are changed. "Addr"
91 * is a process virtual address. "Offset" is a file offset.
92
93 raid:/nfs/raid/src/dist-18.56/src> dump -h temacs
94
95 temacs:
96
97 **** SECTION HEADER TABLE ****
98 [No] Type Flags Addr Offset Size Name
99 Link Info Adralgn Entsize
100
101 [1] 1 2 0x80480d4 0xd4 0x13 .interp
102 0 0 0x1 0
103
104 [2] 5 2 0x80480e8 0xe8 0x388 .hash
105 3 0 0x4 0x4
106
107 [3] 11 2 0x8048470 0x470 0x7f0 .dynsym
108 4 1 0x4 0x10
109
110 [4] 3 2 0x8048c60 0xc60 0x3ad .dynstr
111 0 0 0x1 0
112
113 [5] 9 2 0x8049010 0x1010 0x338 .rel.plt
114 3 7 0x4 0x8
115
116 [6] 1 6 0x8049348 0x1348 0x3 .init
117 0 0 0x4 0
118
119 [7] 1 6 0x804934c 0x134c 0x680 .plt
120 0 0 0x4 0x4
121
122 [8] 1 6 0x80499cc 0x19cc 0x3c56f .text
123 0 0 0x4 0
124
125 [9] 1 6 0x8085f3c 0x3df3c 0x3 .fini
126 0 0 0x4 0
127
128 [10] 1 2 0x8085f40 0x3df40 0x69c .rodata
129 0 0 0x4 0
130
131 [11] 1 2 0x80865dc 0x3e5dc 0xd51 .rodata1
132 0 0 0x4 0
133
134 [12] 1 3 0x8088330 0x3f330 0x20afc .data
135 0 0 0x4 0
136
137 [13] 1 3 0x80a8e2c 0x5fe2c 0x89d .data1
138 0 0 0x4 0
139
140 [14] 1 3 0x80a96cc 0x606cc 0x1a8 .got
141 0 0 0x4 0x4
142
143 [15] 6 3 0x80a9874 0x60874 0x80 .dynamic
144 4 0 0x4 0x8
145
146 [16] 8 3 0x80a98f4 0x608f4 0x449c .bss
147 0 0 0x4 0
148
149 [17] 2 0 0 0x608f4 0x9b90 .symtab
150 18 371 0x4 0x10
151
152 [18] 3 0 0 0x6a484 0x8526 .strtab
153 0 0 0x1 0
154
155 [19] 3 0 0 0x729aa 0x93 .shstrtab
156 0 0 0x1 0
157
158 [20] 1 0 0 0x72a3d 0x68b7 .comment
159 0 0 0x1 0
160
161 raid:/nfs/raid/src/dist-18.56/src> dump -h xemacs
162
163 xemacs:
164
165 **** SECTION HEADER TABLE ****
166 [No] Type Flags Addr Offset Size Name
167 Link Info Adralgn Entsize
168
169 [1] 1 2 0x80480d4 0xd4 0x13 .interp
170 0 0 0x1 0
171
172 [2] 5 2 0x80480e8 0xe8 0x388 .hash
173 3 0 0x4 0x4
174
175 [3] 11 2 0x8048470 0x470 0x7f0 .dynsym
176 4 1 0x4 0x10
177
178 [4] 3 2 0x8048c60 0xc60 0x3ad .dynstr
179 0 0 0x1 0
180
181 [5] 9 2 0x8049010 0x1010 0x338 .rel.plt
182 3 7 0x4 0x8
183
184 [6] 1 6 0x8049348 0x1348 0x3 .init
185 0 0 0x4 0
186
187 [7] 1 6 0x804934c 0x134c 0x680 .plt
188 0 0 0x4 0x4
189
190 [8] 1 6 0x80499cc 0x19cc 0x3c56f .text
191 0 0 0x4 0
192
193 [9] 1 6 0x8085f3c 0x3df3c 0x3 .fini
194 0 0 0x4 0
195
196 [10] 1 2 0x8085f40 0x3df40 0x69c .rodata
197 0 0 0x4 0
198
199 [11] 1 2 0x80865dc 0x3e5dc 0xd51 .rodata1
200 0 0 0x4 0
201
202 [12] 1 3 0x8088330 0x3f330 0x20afc .data
203 0 0 0x4 0
204
205 [13] 1 3 0x80a8e2c 0x5fe2c 0x89d .data1
206 0 0 0x4 0
207
208 [14] 1 3 0x80a96cc 0x606cc 0x1a8 .got
209 0 0 0x4 0x4
210
211 [15] 6 3 0x80a9874 0x60874 0x80 .dynamic
212 4 0 0x4 0x8
213
214 [16] 8 3 0x80c6800 0x7d800 0 .bss
215 0 0 0x4 0
216
217 [17] 2 0 0 0x7d800 0x9b90 .symtab
218 18 371 0x4 0x10
219
220 [18] 3 0 0 0x87390 0x8526 .strtab
221 0 0 0x1 0
222
223 [19] 3 0 0 0x8f8b6 0x93 .shstrtab
224 0 0 0x1 0
225
226 [20] 1 0 0 0x8f949 0x68b7 .comment
227 0 0 0x1 0
228
229 [21] 1 3 0x80a98f4 0x608f4 0x1cf0c .data
230 0 0 0x4 0
231
232 * This is an example of how the file header is changed. "Shoff" is
233 * the section header offset within the file. Since that table is
234 * after the new .data section, it is moved. "Shnum" is the number of
235 * sections, which we increment.
236 *
237 * "Phoff" is the file offset to the program header. "Phentsize" and
238 * "Shentsz" are the program and section header entries sizes respectively.
239 * These can be larger than the apparent struct sizes.
240
241 raid:/nfs/raid/src/dist-18.56/src> dump -f temacs
242
243 temacs:
244
245 **** ELF HEADER ****
246 Class Data Type Machine Version
247 Entry Phoff Shoff Flags Ehsize
248 Phentsize Phnum Shentsz Shnum Shstrndx
249
250 1 1 2 3 1
251 0x80499cc 0x34 0x792f4 0 0x34
252 0x20 5 0x28 21 19
253
254 raid:/nfs/raid/src/dist-18.56/src> dump -f xemacs
255
256 xemacs:
257
258 **** ELF HEADER ****
259 Class Data Type Machine Version
260 Entry Phoff Shoff Flags Ehsize
261 Phentsize Phnum Shentsz Shnum Shstrndx
262
263 1 1 2 3 1
264 0x80499cc 0x34 0x96200 0 0x34
265 0x20 5 0x28 22 19
266
267 * These are the program headers. "Offset" is the file offset to the
268 * segment. "Vaddr" is the memory load address. "Filesz" is the
269 * segment size as it appears in the file, and "Memsz" is the size in
270 * memory. Below, the third segment is the code and the fourth is the
271 * data: the difference between Filesz and Memsz is .bss
272
273 raid:/nfs/raid/src/dist-18.56/src> dump -o temacs
274
275 temacs:
276 ***** PROGRAM EXECUTION HEADER *****
277 Type Offset Vaddr Paddr
278 Filesz Memsz Flags Align
279
280 6 0x34 0x8048034 0
281 0xa0 0xa0 5 0
282
283 3 0xd4 0 0
284 0x13 0 4 0
285
286 1 0x34 0x8048034 0
287 0x3f2f9 0x3f2f9 5 0x1000
288
289 1 0x3f330 0x8088330 0
290 0x215c4 0x25a60 7 0x1000
291
292 2 0x60874 0x80a9874 0
293 0x80 0 7 0
294
295 raid:/nfs/raid/src/dist-18.56/src> dump -o xemacs
296
297 xemacs:
298 ***** PROGRAM EXECUTION HEADER *****
299 Type Offset Vaddr Paddr
300 Filesz Memsz Flags Align
301
302 6 0x34 0x8048034 0
303 0xa0 0xa0 5 0
304
305 3 0xd4 0 0
306 0x13 0 4 0
307
308 1 0x34 0x8048034 0
309 0x3f2f9 0x3f2f9 5 0x1000
310
311 1 0x3f330 0x8088330 0
312 0x3e4d0 0x3e4d0 7 0x1000
313
314 2 0x60874 0x80a9874 0
315 0x80 0 7 0
316
317
70 */ 318 */
71 319
72 #ifndef emacs 320 /* Modified by wtien@urbana.mcd.mot.com of Motorola Inc.
73 #define fatal(a, b, c) fprintf (stderr, a, b, c), exit (1) 321 *
74 #include <string.h> 322 * The above mechanism does not work if the unexeced ELF file is being
75 #else 323 * re-layout by other applications (such as `strip'). All the applications
76 #include <config.h> 324 * that re-layout the internal of ELF will layout all sections in ascending
77 extern void fatal (const char *, ...); 325 * order of their file offsets. After the re-layout, the data2 section will
78 #endif 326 * still be the LAST section in the section header vector, but its file offset
79 327 * is now being pushed far away down, and causes part of it not to be mapped
328 * in (ie. not covered by the load segment entry in PHDR vector), therefore
329 * causes the new binary to fail.
330 *
331 * The solution is to modify the unexec algorithm to insert the new data2
332 * section header right before the new bss section header, so their file
333 * offsets will be in the ascending order. Since some of the section's (all
334 * sections AFTER the bss section) indexes are now changed, we also need to
335 * modify some fields to make them point to the right sections. This is done
336 * by macro PATCH_INDEX. All the fields that need to be patched are:
337 *
338 * 1. ELF header e_shstrndx field.
339 * 2. section header sh_link and sh_info field.
340 * 3. symbol table entry st_shndx field.
341 *
342 * The above example now should look like:
343
344 **** SECTION HEADER TABLE ****
345 [No] Type Flags Addr Offset Size Name
346 Link Info Adralgn Entsize
347
348 [1] 1 2 0x80480d4 0xd4 0x13 .interp
349 0 0 0x1 0
350
351 [2] 5 2 0x80480e8 0xe8 0x388 .hash
352 3 0 0x4 0x4
353
354 [3] 11 2 0x8048470 0x470 0x7f0 .dynsym
355 4 1 0x4 0x10
356
357 [4] 3 2 0x8048c60 0xc60 0x3ad .dynstr
358 0 0 0x1 0
359
360 [5] 9 2 0x8049010 0x1010 0x338 .rel.plt
361 3 7 0x4 0x8
362
363 [6] 1 6 0x8049348 0x1348 0x3 .init
364 0 0 0x4 0
365
366 [7] 1 6 0x804934c 0x134c 0x680 .plt
367 0 0 0x4 0x4
368
369 [8] 1 6 0x80499cc 0x19cc 0x3c56f .text
370 0 0 0x4 0
371
372 [9] 1 6 0x8085f3c 0x3df3c 0x3 .fini
373 0 0 0x4 0
374
375 [10] 1 2 0x8085f40 0x3df40 0x69c .rodata
376 0 0 0x4 0
377
378 [11] 1 2 0x80865dc 0x3e5dc 0xd51 .rodata1
379 0 0 0x4 0
380
381 [12] 1 3 0x8088330 0x3f330 0x20afc .data
382 0 0 0x4 0
383
384 [13] 1 3 0x80a8e2c 0x5fe2c 0x89d .data1
385 0 0 0x4 0
386
387 [14] 1 3 0x80a96cc 0x606cc 0x1a8 .got
388 0 0 0x4 0x4
389
390 [15] 6 3 0x80a9874 0x60874 0x80 .dynamic
391 4 0 0x4 0x8
392
393 [16] 1 3 0x80a98f4 0x608f4 0x1cf0c .data
394 0 0 0x4 0
395
396 [17] 8 3 0x80c6800 0x7d800 0 .bss
397 0 0 0x4 0
398
399 [18] 2 0 0 0x7d800 0x9b90 .symtab
400 19 371 0x4 0x10
401
402 [19] 3 0 0 0x87390 0x8526 .strtab
403 0 0 0x1 0
404
405 [20] 3 0 0 0x8f8b6 0x93 .shstrtab
406 0 0 0x1 0
407
408 [21] 1 0 0 0x8f949 0x68b7 .comment
409 0 0 0x1 0
410
411 */
412
413 /* More mods, by Jack Repenning <jackr@sgi.com>, Fri Aug 11 15:45:52 1995
414
415 Same algorithm as immediately above. However, the detailed
416 calculations of the various locations needed significant
417 overhaul.
418
419 At the point of the old .bss, the file offsets and the memory
420 addresses do distinct, slightly snaky things:
421
422 offset of .bss is meaningless and unpredictable
423 addr of .bss is meaningful
424 alignment of .bss is important to addr, so there may be a small
425 gap in address range before start of bss
426 offset of next section is rounded up modulo 0x1000
427 the hole so-introduced is zero-filled, so it can be mapped in as
428 the first partial-page of bss (the rest of the bss is mapped from
429 /dev/zero)
430 I suppose you could view this not as a hole, but as the beginning
431 of the bss, actually present in the file. But you should not
432 push that worldview too far, as the linker still knows that the
433 "offset" claimed for the bss is unused, and seems not always
434 careful about setting it.
435
436 We are doing all our tricks at this same rather complicated
437 location (isn't life fun?):
438
439 insert a new data section to contain now-initialized old bss and
440 heap
441 define a zero-length bss just so there is one
442
443 The offset of the new data section is dictated by its current
444 address (which, of course, we want also to be its addr): the
445 loader maps in the whole file region containing old data, rodata,
446 got, and new data as a single mapped segment, starting at the
447 address of the first chunk; the rest have to be laid out in the
448 file such that the map into the right spots. That is:
449
450 offset(newdata) ==
451 addrInRunningMemory(newdata)-aIRM(olddata)
452 + offset(oldData)
453
454 This would not necessarily match the oldbss offset, even if it
455 were carefully calculated! We must compute this.
456
457 The linker that built temacs has also already arranged that
458 olddata is properly page-aligned (not necessarily beginning on a
459 page, but rather that a page's worth of the low bits of addr and
460 offset match). We preserve this.
461
462 addr(bss) is alignment-constrained from the end of the new data.
463 Since we base endof(newdata) on sbrk(), we have a page boundary
464 (in both offset and addr) and meet any alignment constraint,
465 needing no alignment adjustment of this location and no
466 mini-hole. Or, if you like, we've allowed sbrk() to "compute"
467 the mini-hole size for us.
468
469 That puts newbss beginning on a page boundary, both in offset and
470 addr. (offset(bss) is still meaningless, but what the heck,
471 we'll fix it up.)
472
473 Since newbss has zero length, and its offset (however
474 meaningless) is page aligned, we place the next section exactly
475 there, with no hole needed to restore page alignment.
476
477 So, the shift for all sections beyond the playing field is:
478
479 new_bss_addr - roundup(old_bss_addr,0x1000)
480
481 */
482 /* Still more mods... Olivier Galibert 19971705
483 - support for .sbss section (automagically changed to data without
484 name change)
485 - support for 64bits ABI (will need a bunch of fixes in the rest
486 of the code before it works
487 */
488
80 #include <sys/types.h> 489 #include <sys/types.h>
81 #include <stdio.h> 490 #include <stdio.h>
82 #include <sys/stat.h> 491 #include <sys/stat.h>
83 #include <memory.h> 492 #include <memory.h>
493 #include <string.h>
84 #include <errno.h> 494 #include <errno.h>
85 #include <unistd.h> 495 #include <unistd.h>
86 #include <fcntl.h> 496 #include <fcntl.h>
87 #include <elf.h> 497 #include <elf.h>
498 #include <sym.h> /* for HDRR declaration */
88 #include <sys/mman.h> 499 #include <sys/mman.h>
89 #if defined (__sony_news) && defined (_SYSTYPE_SYSV) 500 #include <config.h>
90 #include <sys/elf_mips.h> 501 #include "lisp.h"
91 #include <sym.h> 502
92 #endif /* __sony_news && _SYSTYPE_SYSV */ 503 /* in 64bits mode, use 64bits elf */
93 #if __sgi 504 #ifdef _ABI64
94 #include <syms.h> /* for HDRR declaration */ 505 typedef Elf64_Shdr l_Elf_Shdr;
95 #endif /* __sgi */ 506 typedef Elf64_Phdr l_Elf_Phdr;
96 507 typedef Elf64_Ehdr l_Elf_Ehdr;
97 #if __GNU_LIBRARY__ - 0 >= 6 508 typedef Elf64_Addr l_Elf_Addr;
98 # include <link.h> /* get ElfW etc */ 509 typedef Elf64_Word l_Elf_Word;
510 typedef Elf64_Off l_Elf_Off;
511 typedef Elf64_Sym l_Elf_Sym;
512 #else
513 typedef Elf32_Shdr l_Elf_Shdr;
514 typedef Elf32_Phdr l_Elf_Phdr;
515 typedef Elf32_Ehdr l_Elf_Ehdr;
516 typedef Elf32_Addr l_Elf_Addr;
517 typedef Elf32_Word l_Elf_Word;
518 typedef Elf32_Off l_Elf_Off;
519 typedef Elf32_Sym l_Elf_Sym;
99 #endif 520 #endif
100 521
101 #ifndef ElfW
102 # ifdef __STDC__
103 # define ElfBitsW(bits, type) Elf##bits##_##type
104 # else
105 # define ElfBitsW(bits, type) Elf/**/bits/**/_/**/type
106 # endif
107 # ifdef _LP64
108 # define ELFSIZE 64
109 # else
110 # define ELFSIZE 32
111 # endif
112 /* This macro expands `bits' before invoking ElfBitsW. */
113 # define ElfExpandBitsW(bits, type) ElfBitsW (bits, type)
114 # define ElfW(type) ElfExpandBitsW (ELFSIZE, type)
115 #endif
116
117 #ifndef ELF_BSS_SECTION_NAME
118 #define ELF_BSS_SECTION_NAME ".bss"
119 #endif
120 522
121 /* Get the address of a particular section or program header entry, 523 /* Get the address of a particular section or program header entry,
122 * accounting for the size of the entries. */ 524 * accounting for the size of the entries.
525 */
123 526
124 #define OLD_SECTION_H(n) \ 527 #define OLD_SECTION_H(n) \
125 (*(ElfW(Shdr) *) ((byte *) old_section_h + old_file_h->e_shentsize * (n))) 528 (*(l_Elf_Shdr *) ((byte *) old_section_h + old_file_h->e_shentsize * (n)))
126 #define NEW_SECTION_H(n) \ 529 #define NEW_SECTION_H(n) \
127 (*(ElfW(Shdr) *) ((byte *) new_section_h + new_file_h->e_shentsize * (n))) 530 (*(l_Elf_Shdr *) ((byte *) new_section_h + new_file_h->e_shentsize * (n)))
128 #define OLD_PROGRAM_H(n) \ 531 #define OLD_PROGRAM_H(n) \
129 (*(ElfW(Phdr) *) ((byte *) old_program_h + old_file_h->e_phentsize * (n))) 532 (*(l_Elf_Phdr *) ((byte *) old_program_h + old_file_h->e_phentsize * (n)))
130 #define NEW_PROGRAM_H(n) \ 533 #define NEW_PROGRAM_H(n) \
131 (*(ElfW(Phdr) *) ((byte *) new_program_h + new_file_h->e_phentsize * (n))) 534 (*(l_Elf_Phdr *) ((byte *) new_program_h + new_file_h->e_phentsize * (n)))
132 535
133 #define PATCH_INDEX(n) \ 536 #define PATCH_INDEX(n) \
134 do { \ 537 do { \
135 if ((int) (n) >= growme_index) \ 538 if ((n) >= old_bss_index) \
136 (n)++; } while (0) 539 (n)++; } while (0)
137
138 typedef unsigned char byte; 540 typedef unsigned char byte;
139 541
140 /* Round X up to a multiple of Y. */ 542 /* Round X up to a multiple of Y. */
141 543
142 static ElfW(Addr) 544 int
143 round_up (ElfW(Addr) x, ElfW(Addr) y) 545 round_up (x, y)
546 int x, y;
144 { 547 {
145 int rem = x % y; 548 int rem = x % y;
146 if (rem == 0) 549 if (rem == 0)
147 return x; 550 return x;
148 return x - rem + y; 551 return x - rem + y;
154 557
155 If we don't find the section NAME, that is a fatal error 558 If we don't find the section NAME, that is a fatal error
156 if NOERROR is 0; we return -1 if NOERROR is nonzero. */ 559 if NOERROR is 0; we return -1 if NOERROR is nonzero. */
157 560
158 static int 561 static int
159 find_section (char *name, 562 find_section (name, section_names, file_name, old_file_h, old_section_h, noerror)
160 const char *section_names, 563 char *name;
161 char *file_name, 564 char *section_names;
162 ElfW(Ehdr) *old_file_h, 565 char *file_name;
163 ElfW(Shdr) *old_section_h, 566 l_Elf_Ehdr *old_file_h;
164 int noerror) 567 l_Elf_Shdr *old_section_h;
568 int noerror;
165 { 569 {
166 int idx; 570 int idx;
167 571
168 for (idx = 1; idx < old_file_h->e_shnum; idx++) 572 for (idx = 1; idx < old_file_h->e_shnum; idx++)
169 { 573 {
171 fprintf (stderr, "Looking for %s - found %s\n", name, 575 fprintf (stderr, "Looking for %s - found %s\n", name,
172 section_names + OLD_SECTION_H (idx).sh_name); 576 section_names + OLD_SECTION_H (idx).sh_name);
173 #endif 577 #endif
174 if (!strcmp (section_names + OLD_SECTION_H (idx).sh_name, 578 if (!strcmp (section_names + OLD_SECTION_H (idx).sh_name,
175 name)) 579 name))
176 return idx; 580 break;
177 } 581 }
178 582 if (idx == old_file_h->e_shnum)
179 /* If we're here, we found nothing or return did not work */ 583 {
180 if ( ! noerror) 584 if (noerror)
181 fatal ("Can't find %s in %s.\n", name, file_name); 585 return -1;
182 586 else
183 return -1; 587 fatal ("Can't find .bss in %s.\n", file_name);
588 }
589
590 return idx;
184 } 591 }
185 592
186 /* **************************************************************** 593 /* ****************************************************************
187 * unexec 594 * unexec
188 * 595 *
190 * 597 *
191 * In ELF, this works by replacing the old .bss section with a new 598 * In ELF, this works by replacing the old .bss section with a new
192 * .data section, and inserting an empty .bss immediately afterwards. 599 * .data section, and inserting an empty .bss immediately afterwards.
193 * 600 *
194 */ 601 */
195 void 602 int
196 unexec (char *new_name, 603 unexec (new_name, old_name, data_start, bss_start, entry_address)
197 char *old_name, 604 char *new_name, *old_name;
198 uintptr_t data_start, 605 uintptr_t data_start, bss_start, entry_address;
199 uintptr_t bss_start,
200 uintptr_t entry_address)
201 { 606 {
202 int old_file; 607 extern uintptr_t bss_end;
203 608 int new_file, old_file, new_file_size;
609
610 /* Pointers to the base of the image of the two files. */
611 caddr_t old_base, new_base;
612
613 /* Pointers to the file, program and section headers for the old and new
614 files. */
615 l_Elf_Ehdr *old_file_h, *new_file_h;
616 l_Elf_Phdr *old_program_h, *new_program_h;
617 l_Elf_Shdr *old_section_h, *new_section_h;
618
619 /* Point to the section name table in the old file. */
620 char *old_section_names;
621
622 l_Elf_Addr old_bss_addr, new_bss_addr;
623 l_Elf_Addr old_base_addr;
624 l_Elf_Word old_bss_size, new_data2_size;
625 l_Elf_Off new_data2_offset, new_base_offset;
626 l_Elf_Addr new_data2_addr;
627 l_Elf_Addr new_offsets_shift;
628
629 int n, nn, old_bss_index, old_data_index;
630 int old_mdebug_index, old_sbss_index;
204 struct stat stat_buf; 631 struct stat stat_buf;
205 caddr_t old_base, new_base; 632
206 633 /* Open the old file & map it into the address space. */
207 ElfW(Ehdr) *old_file_h, * new_file_h; 634
208 ElfW(Phdr) *old_program_h, * new_program_h; 635 old_file = open (old_name, O_RDONLY);
209 ElfW(Shdr) *old_section_h, * new_section_h; 636
210 ElfW(Shdr) * growme = NULL, * grown = NULL; 637 if (old_file < 0)
211 ElfW(Addr) old_bss_addr = 0, new_data2_addr = 0; 638 fatal ("Can't open %s for reading: errno %d\n", old_name, errno);
212
213 int growme_index = -1;
214 int n, nn;
215 const char *old_section_names;
216 int old_mdebug_index, old_data_index;
217 int new_bss_addr, new_data2_size, new_data2_offset, new_file, new_file_size;
218
219 /* Open the old file */
220 if ( (old_file = open (old_name, O_RDONLY)) < 0 )
221 fatal ("Can't open %s for reading: errno %d\n", old_name, errno);
222 639
223 if (fstat (old_file, &stat_buf) == -1) 640 if (fstat (old_file, &stat_buf) == -1)
224 fatal ("Can't fstat (%s): errno %d\n", old_name, errno); 641 fatal ("Can't fstat(%s): errno %d\n", old_name, errno);
225 642
226 /* map old file into the address space. */ 643 old_base = mmap (0, stat_buf.st_size, PROT_READ, MAP_SHARED, old_file, 0);
227 old_base = (caddr_t) mmap ((caddr_t) 0, stat_buf.st_size, 644
228 PROT_READ, MAP_SHARED, old_file, 0); 645 if (old_base == (caddr_t) -1)
229 if (old_base == (caddr_t) MAP_FAILED) 646 fatal ("Can't mmap(%s): errno %d\n", old_name, errno);
230 fatal ("Can't mmap (%s): errno %d\n", old_name, errno); 647
231 648 #ifdef DEBUG
232 old_file_h = (ElfW(Ehdr) *) old_base; 649 fprintf (stderr, "mmap(%s, %x) -> %x\n", old_name, stat_buf.st_size,
233 old_program_h = (ElfW(Phdr) *) ((byte *) old_base + old_file_h->e_phoff); 650 old_base);
234 old_section_h = (ElfW(Shdr) *) ((byte *) old_base + old_file_h->e_shoff); 651 #endif
235 old_section_names = (const char *) old_base 652
236 + OLD_SECTION_H (old_file_h->e_shstrndx).sh_offset; 653 /* Get pointers to headers & section names. */
237 654
238 /* Find a section which we will grow by looking for the SHT_NOBITS 655 old_file_h = (l_Elf_Ehdr *) old_base;
239 * section with ALLOCATE flag and with the biggest address. */ 656 old_program_h = (l_Elf_Phdr *) ((byte *) old_base + old_file_h->e_phoff);
240 for (n = 1; n < old_file_h->e_shnum; n++) { 657 old_section_h = (l_Elf_Shdr *) ((byte *) old_base + old_file_h->e_shoff);
241 ElfW(Shdr) * sh = & OLD_SECTION_H(n); 658 old_section_names
242 659 = (char *) old_base + OLD_SECTION_H (old_file_h->e_shstrndx).sh_offset;
243 if ((sh->sh_type == SHT_NOBITS) && (sh->sh_flags & SHF_ALLOC)) { 660
244 if ( old_bss_addr < sh->sh_addr ) { 661 /* Find the mdebug section, if any. */
245 growme = sh; 662
246 growme_index = n; 663 old_mdebug_index = find_section (".mdebug", old_section_names,
247 new_data2_addr = old_bss_addr = sh->sh_addr; 664 old_name, old_file_h, old_section_h, 1);
248 } 665
249 } 666 /* Find the .sbss section, if any. */
250 } 667
251 668 old_sbss_index = find_section (".sbss", old_section_names,
252 if (growme == NULL ) 669 old_name, old_file_h, old_section_h, 1);
253 fatal ("Can't find a section to grow\n", 0, 0); 670
671 if (old_sbss_index != -1 && (OLD_SECTION_H (old_sbss_index).sh_type == SHT_PROGBITS))
672 old_sbss_index = -1;
673
674 /* Find the old .bss section. */
675
676 old_bss_index = find_section (".bss", old_section_names,
677 old_name, old_file_h, old_section_h, 0);
678
679 /* Find the old .data section. Figure out parameters of
680 the new data2 and bss sections. */
254 681
255 old_data_index = find_section (".data", old_section_names, 682 old_data_index = find_section (".data", old_section_names,
256 old_name, old_file_h, old_section_h, 0); 683 old_name, old_file_h, old_section_h, 0);
257 684
258 new_bss_addr = (ElfW(Addr)) sbrk (0); 685 old_bss_addr = OLD_SECTION_H (old_bss_index).sh_addr;
259 new_data2_size = new_bss_addr - old_bss_addr; 686 old_bss_size = OLD_SECTION_H (old_bss_index).sh_size;
687 old_base_addr = old_sbss_index == -1 ? old_bss_addr : OLD_SECTION_H (old_sbss_index).sh_addr;
688 #if defined(emacs) || !defined(DEBUG)
689 bss_end = (uintptr_t) sbrk (0);
690 new_bss_addr = (l_Elf_Addr) bss_end;
691 #else
692 new_bss_addr = old_bss_addr + old_bss_size + 0x1234;
693 #endif
694 new_data2_addr = old_bss_addr;
695 new_data2_size = new_bss_addr - old_bss_addr;
260 new_data2_offset = OLD_SECTION_H (old_data_index).sh_offset + 696 new_data2_offset = OLD_SECTION_H (old_data_index).sh_offset +
261 (new_data2_addr - OLD_SECTION_H (old_data_index).sh_addr); 697 (new_data2_addr - OLD_SECTION_H (old_data_index).sh_addr);
262 698 new_base_offset = OLD_SECTION_H (old_data_index).sh_offset +
263 if ( new_bss_addr < old_bss_addr + growme->sh_size ) 699 (old_base_addr - OLD_SECTION_H (old_data_index).sh_addr);
264 fatal (".bss shrank when undumping???\n", 0, 0); 700 new_offsets_shift = new_bss_addr -
265 701 ((old_base_addr & ~0xfff) + ((old_base_addr & 0xfff) ? 0x1000 : 0));
266 /* Set the output file to the right size and mmap it. */ 702
267 if ( (new_file = open (new_name, O_RDWR | O_CREAT, 0666)) < 0 ) 703 #ifdef DEBUG
268 fatal ("Can't create (%s): errno %d\n", new_name, errno); 704 fprintf (stderr, "old_bss_index %d\n", old_bss_index);
269 705 fprintf (stderr, "old_bss_addr %x\n", old_bss_addr);
270 new_file_size = stat_buf.st_size + old_file_h->e_shentsize + new_data2_size; 706 fprintf (stderr, "old_bss_size %x\n", old_bss_size);
707 fprintf (stderr, "old_base_addr %x\n", old_base_addr);
708 fprintf (stderr, "new_bss_addr %x\n", new_bss_addr);
709 fprintf (stderr, "new_data2_addr %x\n", new_data2_addr);
710 fprintf (stderr, "new_data2_size %x\n", new_data2_size);
711 fprintf (stderr, "new_data2_offset %x\n", new_data2_offset);
712 fprintf (stderr, "new_offsets_shift %x\n", new_offsets_shift);
713 #endif
714
715 if ((unsigned) new_bss_addr < (unsigned) old_bss_addr + old_bss_size)
716 fatal (".bss shrank when undumping???\n");
717
718 /* Set the output file to the right size and mmap it. Set
719 pointers to various interesting objects. stat_buf still has
720 old_file data. */
721
722 new_file = open (new_name, O_RDWR | O_CREAT, 0666);
723 if (new_file < 0)
724 fatal ("Can't creat (%s): errno %d\n", new_name, errno);
725
726 new_file_size = stat_buf.st_size /* old file size */
727 + old_file_h->e_shentsize /* one new section header */
728 + new_offsets_shift; /* trailing section shift */
271 729
272 if (ftruncate (new_file, new_file_size)) 730 if (ftruncate (new_file, new_file_size))
273 fatal ("Can't ftruncate (%s): errno %d\n", new_name, errno); 731 fatal ("Can't ftruncate (%s): errno %d\n", new_name, errno);
274 732
275 new_base = (caddr_t) mmap ((caddr_t) 0, new_file_size, 733 new_base = mmap (0, new_file_size, PROT_READ | PROT_WRITE, MAP_SHARED,
276 PROT_READ | PROT_WRITE, 734 new_file, 0);
277 #ifdef UNEXEC_USE_MAP_PRIVATE
278 MAP_PRIVATE,
279 #else
280 MAP_SHARED,
281 #endif
282 new_file, 0);
283 735
284 if (new_base == (caddr_t) -1) 736 if (new_base == (caddr_t) -1)
285 fatal ("Can't mmap (%s): errno %d\n", new_name, errno); 737 fatal ("Can't mmap (%s): errno %d\n", new_name, errno);
286 738
287 new_file_h = (ElfW(Ehdr) *) new_base; 739 new_file_h = (l_Elf_Ehdr *) new_base;
288 new_program_h = (ElfW(Phdr) *) ((byte *) new_base + old_file_h->e_phoff); 740 new_program_h = (l_Elf_Phdr *) ((byte *) new_base + old_file_h->e_phoff);
289 new_section_h = (ElfW(Shdr) *) ((byte *) new_base + old_file_h->e_shoff + 741 new_section_h
290 new_data2_size); 742 = (l_Elf_Shdr *) ((byte *) new_base + old_file_h->e_shoff
743 + new_offsets_shift);
291 744
292 /* Make our new file, program and section headers as copies of the 745 /* Make our new file, program and section headers as copies of the
293 * originals. */ 746 originals. */
747
294 memcpy (new_file_h, old_file_h, old_file_h->e_ehsize); 748 memcpy (new_file_h, old_file_h, old_file_h->e_ehsize);
295 memcpy (new_program_h, old_program_h, 749 memcpy (new_program_h, old_program_h,
296 old_file_h->e_phnum * old_file_h->e_phentsize); 750 old_file_h->e_phnum * old_file_h->e_phentsize);
297 751
298 /* Modify the e_shstrndx if necessary. */ 752 /* Modify the e_shstrndx if necessary. */
299 PATCH_INDEX (new_file_h->e_shstrndx); 753 PATCH_INDEX (new_file_h->e_shstrndx);
300 754
301 /* Fix up file header. We'll add one section. Section header is 755 /* Fix up file header. We'll add one section. Section header is
302 * further away now. */ 756 further away now. */
303 new_file_h->e_shoff += new_data2_size; 757
758 new_file_h->e_shoff += new_offsets_shift;
304 new_file_h->e_shnum += 1; 759 new_file_h->e_shnum += 1;
305 760
306 /* Fix up a new program header by extending the writable data 761
307 * segment so that the bss area is covered too. Find that segment by
308 * looking for one that starts before and ends after the .bss and is
309 * PT_LOADable. */
310 for (n = new_file_h->e_phnum - 1; n >= 0; n--) {
311 ElfW(Phdr) * ph = & NEW_PROGRAM_H(n);
312 #ifdef DEBUG 762 #ifdef DEBUG
313 printf ("%d @ %0x + %0x against %0x + %0x", 763 fprintf (stderr, "Old section offset %x\n", old_file_h->e_shoff);
314 n, ph->p_vaddr, ph->p_memsz,growme->sh_addr, growme->sh_size); 764 fprintf (stderr, "Old section count %d\n", old_file_h->e_shnum);
765 fprintf (stderr, "New section offset %x\n", new_file_h->e_shoff);
766 fprintf (stderr, "New section count %d\n", new_file_h->e_shnum);
315 #endif 767 #endif
316 if ((ph->p_type == PT_LOAD) && 768
317 (ph->p_vaddr <= growme->sh_addr) && 769 /* Fix up a new program header. Extend the writable data segment so
318 ((ph->p_vaddr+ph->p_memsz) >= (growme->sh_addr + growme->sh_size))) { 770 that the bss area is covered too. Find that segment by looking
319 /* Make sure that the size includes any padding before the 771 for a segment that ends just before the .bss area. Make sure
320 * old .bss section. */ 772 that no segments are above the new .data2. Put a loop at the end
321 ph->p_memsz = ph->p_filesz = new_bss_addr - ph->p_vaddr; 773 to adjust the offset and address of any segment that is above
322 #ifdef DEBUG 774 data2, just in case we decide to allow this later. */
323 puts (" That's the one!"); 775
776 for (n = new_file_h->e_phnum - 1; n >= 0; n--)
777 {
778 /* Compute maximum of all requirements for alignment of section. */
779 int alignment = (NEW_PROGRAM_H (n)).p_align;
780 if ((OLD_SECTION_H (old_bss_index)).sh_addralign > alignment)
781 alignment = OLD_SECTION_H (old_bss_index).sh_addralign;
782
783 /* Supposedly this condition is okay for the SGI. */
784 #if 0
785 if (NEW_PROGRAM_H (n).p_vaddr + NEW_PROGRAM_H (n).p_filesz > old_base_addr)
786 fatal ("Program segment above .bss in %s\n", old_name);
324 #endif 787 #endif
325 break; 788
326 } 789 if (NEW_PROGRAM_H (n).p_type == PT_LOAD
327 #ifdef DEBUG 790 && (round_up ((NEW_PROGRAM_H (n)).p_vaddr
328 putchar ('\n'); 791 + (NEW_PROGRAM_H (n)).p_filesz,
792 alignment)
793 == round_up (old_base_addr, alignment)))
794 break;
795 }
796 if (n < 0)
797 fatal ("Couldn't find segment next to %s in %s\n",
798 old_sbss_index == -1 ? ".sbss" : ".bss", old_name);
799
800 NEW_PROGRAM_H (n).p_filesz += new_offsets_shift;
801 NEW_PROGRAM_H (n).p_memsz = NEW_PROGRAM_H (n).p_filesz;
802
803 #if 1 /* Maybe allow section after data2 - does this ever happen? */
804 for (n = new_file_h->e_phnum - 1; n >= 0; n--)
805 {
806 if (NEW_PROGRAM_H (n).p_vaddr
807 && NEW_PROGRAM_H (n).p_vaddr >= new_data2_addr)
808 NEW_PROGRAM_H (n).p_vaddr += new_offsets_shift - old_bss_size;
809
810 if (NEW_PROGRAM_H (n).p_offset >= new_data2_offset)
811 NEW_PROGRAM_H (n).p_offset += new_offsets_shift;
812 }
329 #endif 813 #endif
330 } 814
331 815 /* Fix up section headers based on new .data2 section. Any section
332 if (n < 0) 816 whose offset or virtual address is after the new .data2 section
333 fatal ("Couldn't find segment which covers %s", 817 gets its value adjusted. .bss size becomes zero and new address
334 old_section_names + growme->sh_name); 818 is set. data2 section header gets added by copying the existing
335 819 .data header and modifying the offset, address and size. */
336 /* Walk through all section headers, insert the new data2 section 820 for (old_data_index = 1; old_data_index < old_file_h->e_shnum;
337 * right before the new bss section. */ 821 old_data_index++)
338 for (n = 1, nn = 1; n < (int) old_file_h->e_shnum; n++, nn++) { 822 if (!strcmp (old_section_names + OLD_SECTION_H (old_data_index).sh_name,
339 ElfW(Shdr) * nsec = & NEW_SECTION_H(nn); 823 ".data"))
340 ElfW(Shdr) * osec = & OLD_SECTION_H(n); 824 break;
341 825 if (old_data_index == old_file_h->e_shnum)
342 /* If this is the section we want to grow, insert the new data 826 fatal ("Can't find .data in %s.\n", old_name);
343 * section before it. */ 827
344 if ( osec == growme ) { 828 /* Walk through all section headers, insert the new data2 section right
345 /* Steal the data section header for this data2 section but 829 before the new bss section. */
346 * use the * 'grow' section's alignment. This * will assure 830 for (n = 1, nn = 1; n < old_file_h->e_shnum; n++, nn++)
347 * that the new section * always be placed in the same spot 831 {
348 * * as the old section by any other * application. */ 832 caddr_t src;
349 ElfW(Shdr) * od = &OLD_SECTION_H(old_data_index); 833
350 834 /* XEmacs change: */
351 memcpy (nsec, od, new_file_h->e_shentsize); 835 if (n < old_bss_index)
352 836 {
353 nsec->sh_addr = new_data2_addr; 837 memcpy (&NEW_SECTION_H (nn), &OLD_SECTION_H (n),
354 nsec->sh_offset = new_data2_offset; 838 old_file_h->e_shentsize);
355 nsec->sh_size = new_data2_size; 839
356 nsec->sh_addralign = osec->sh_addralign; 840 }
357 841 else if (n == old_bss_index)
358 /* Copy over what we have in memory now. */ 842 {
359 memcpy (nsec->sh_offset + new_base, (caddr_t) osec->sh_addr, 843
844 /* If it is bss section, insert the new data2 section before it. */
845 /* Steal the data section header for this data2 section. */
846 memcpy (&NEW_SECTION_H (nn), &OLD_SECTION_H (old_data_index),
847 new_file_h->e_shentsize);
848
849 NEW_SECTION_H (nn).sh_addr = new_data2_addr;
850 NEW_SECTION_H (nn).sh_offset = new_data2_offset;
851 NEW_SECTION_H (nn).sh_size = new_data2_size;
852 /* Use the bss section's alignment. This will assure that the
853 new data2 section always be placed in the same spot as the old
854 bss section by any other application. */
855 NEW_SECTION_H (nn).sh_addralign = OLD_SECTION_H (n).sh_addralign;
856
857 /* Now copy over what we have in the memory now. */
858 memcpy (NEW_SECTION_H (nn).sh_offset + new_base,
859 (caddr_t) OLD_SECTION_H (n).sh_addr,
360 new_data2_size); 860 new_data2_size);
361 nn++; 861 nn++;
362 grown = nsec++; 862 memcpy (&NEW_SECTION_H (nn), &OLD_SECTION_H (n),
363 } 863 old_file_h->e_shentsize);
364 864
365 memcpy (nsec, osec, old_file_h->e_shentsize); 865 /* The new bss section's size is zero, and its file offset and virtual
366 866 address should be off by NEW_OFFSETS_SHIFT. */
367 if ( osec == growme ) { 867 NEW_SECTION_H (nn).sh_offset += new_offsets_shift;
368 /* The new bss section's size is zero, and its file offset 868 NEW_SECTION_H (nn).sh_addr = new_bss_addr;
369 * and virtual address should be off by NEW_DATA2_SIZE. */ 869 /* Let the new bss section address alignment be the same as the
370 nsec->sh_offset = grown->sh_offset + new_data2_size; 870 section address alignment followed the old bss section, so
371 nsec->sh_addr = grown->sh_addr + new_data2_size; 871 this section will be placed in exactly the same place. */
372 872 NEW_SECTION_H (nn).sh_addralign = OLD_SECTION_H (n).sh_addralign;
373 /* Let the new bss section address alignment be the same as 873 NEW_SECTION_H (nn).sh_size = 0;
374 * the section address alignment followed the old bss 874 }
375 * section, so this section will be placed in exactly the 875 else /* n > old_bss_index */
376 * same place. */ 876 memcpy (&NEW_SECTION_H (nn), &OLD_SECTION_H (n),
377 nsec->sh_addralign = osec->sh_addralign; 877 old_file_h->e_shentsize);
378 nsec->sh_size = 0; 878
379 } else { 879 /* Any section that was original placed AFTER the bss
380 /* Any section that was originally placed AFTER the bss 880 section must now be adjusted by NEW_OFFSETS_SHIFT. */
381 * section should now be off by NEW_DATA2_SIZE. */ 881
382 if ( round_up (nsec->sh_offset, growme->sh_addralign) >= 882 if (NEW_SECTION_H (nn).sh_offset >= new_base_offset)
383 new_data2_offset) 883 NEW_SECTION_H (nn).sh_offset += new_offsets_shift;
384 nsec->sh_offset += new_data2_size; 884
385 }
386
387 /* Any section that was originally placed after the section *
388 * header table should now be off by the size of one section
389 * header table entry. */
390 if (nsec->sh_offset > new_file_h->e_shoff)
391 nsec->sh_offset += new_file_h->e_shentsize;
392
393
394 /* If any section hdr refers to the section after the new .data 885 /* If any section hdr refers to the section after the new .data
395 * section, make it refer to next one because we have inserted a 886 section, make it refer to next one because we have inserted
396 * new section in between. */ 887 a new section in between. */
397 PATCH_INDEX (nsec->sh_link); 888
398 889 PATCH_INDEX (NEW_SECTION_H (nn).sh_link);
399 /* For symbol tables, info is a symbol table index, so don't 890 /* For symbol tables, info is a symbol table index,
400 * change it. */ 891 so don't change it. */
401 if (nsec->sh_type != SHT_SYMTAB && nsec->sh_type != SHT_DYNSYM) 892 if (NEW_SECTION_H (nn).sh_type != SHT_SYMTAB
402 PATCH_INDEX (nsec->sh_info); 893 && NEW_SECTION_H (nn).sh_type != SHT_DYNSYM)
403 894 PATCH_INDEX (NEW_SECTION_H (nn).sh_info);
404 /* Any section which used to be NOBITS will now becomes PROGBITS 895
405 * if it's ALLOC-atable, unless, of cause, it's not the one we 896 /* Fix the type and alignment for the .sbss section */
406 * decided to grow */ 897 if ((old_sbss_index != -1) && !strcmp (old_section_names + NEW_SECTION_H (nn).sh_name, ".sbss"))
407 if ( (osec->sh_type == SHT_NOBITS) && (osec->sh_flags & SHF_ALLOC) && 898 {
408 (osec != growme ) ) { 899 NEW_SECTION_H (nn).sh_type = SHT_PROGBITS;
409 nsec->sh_type = SHT_PROGBITS; 900 NEW_SECTION_H (nn).sh_offset = round_up (NEW_SECTION_H (nn).sh_offset,
410 } 901 NEW_SECTION_H (nn).sh_addralign);
411 902 }
412 /* Now, start to copy the content of sections */ 903
413 if ( nsec->sh_type != SHT_NULL || nsec->sh_type != SHT_NOBITS ) { 904 /* Now, start to copy the content of sections. */
414 905 if (NEW_SECTION_H (nn).sh_type == SHT_NULL
415 /* Write out the sections. .data and .data1 (and data2, 906 || NEW_SECTION_H (nn).sh_type == SHT_NOBITS)
416 * called ".data" in the strings table) get copied from the 907 continue;
417 * current process instead of the old file. */ 908
418 caddr_t src = old_base + osec->sh_offset; 909 /* Write out the sections. .data, .data1 and .sbss (and data2, called
419 const char * secname = old_section_names + nsec->sh_name; 910 ".data" in the strings table) get copied from the current process
420 const char * names[] = { 911 instead of the old file. */
421 ".data",".sdata", ".lit4", ".lit8", ".sdata1", ".data1", 912 if (!strcmp (old_section_names + NEW_SECTION_H (nn).sh_name, ".data")
422 ".sbss", NULL}; 913 || !strcmp (old_section_names + NEW_SECTION_H (nn).sh_name, ".data1")
423 int i; 914 || !strcmp (old_section_names + NEW_SECTION_H (nn).sh_name, ".got")
424 915 || !strcmp (old_section_names + NEW_SECTION_H (nn).sh_name, ".sbss"))
425 for ( i=0; names[i] != NULL; i++ ) { 916 src = (caddr_t) OLD_SECTION_H (n).sh_addr;
426 if ( ! strcmp (secname, names[i]) ) { 917 else
427 src = (caddr_t) osec->sh_addr; 918 src = old_base + OLD_SECTION_H (n).sh_offset;
428 break; 919
429 } 920 memcpy (NEW_SECTION_H (nn).sh_offset + new_base, src,
430 } 921 NEW_SECTION_H (nn).sh_size);
431 922
432 memcpy (nsec->sh_offset + new_base, src, nsec->sh_size); 923 /* Adjust the HDRR offsets in .mdebug and copy the
433 } 924 line data if it's in its usual 'hole' in the object.
434 925 Makes the new file debuggable with dbx.
435 old_mdebug_index = find_section (".mdebug", old_section_names, 926 patches up two problems: the absolute file offsets
436 old_name, old_file_h, old_section_h, 1); 927 in the HDRR record of .mdebug (see /usr/include/syms.h), and
437 928 the ld bug that gets the line table in a hole in the
438 #if defined (__sony_news) && defined (_SYSTYPE_SYSV) 929 elf file rather than in the .mdebug section proper.
439 if (nsec->sh_type == SHT_MIPS_DEBUG && old_mdebug_index != -1) { 930 David Anderson. davea@sgi.com Jan 16,1994. */
440 int diff = nsec->sh_offset-OLD_SECTION_H(old_mdebug_index).sh_offset; 931 if (n == old_mdebug_index)
441 HDRR *phdr = (HDRR *)(nsec->sh_offset + new_base); 932 {
442
443 if (diff) {
444 phdr->cbLineOffset += diff;
445 phdr->cbDnOffset += diff;
446 phdr->cbPdOffset += diff;
447 phdr->cbSymOffset += diff;
448 phdr->cbOptOffset += diff;
449 phdr->cbAuxOffset += diff;
450 phdr->cbSsOffset += diff;
451 phdr->cbSsExtOffset += diff;
452 phdr->cbFdOffset += diff;
453 phdr->cbRfdOffset += diff;
454 phdr->cbExtOffset += diff;
455 }
456 }
457 #endif /* __sony_news && _SYSTYPE_SYSV */
458
459 #if __sgi
460 /* Adjust the HDRR offsets in .mdebug and copy the line data if
461 * it's in its usual 'hole' in the object. Makes the new file
462 * debuggable with dbx. patches up two problems: the absolute
463 * file offsets in the HDRR record of .mdebug (see
464 * /usr/include/syms.h), and the ld bug that gets the line table
465 * in a hole in the elf file rather than in the .mdebug section
466 * proper.
467 *
468 * David Anderson. davea@sgi.com Jan 16,1994 */
469 #define MDEBUGADJUST(__ct,__fileaddr) \ 933 #define MDEBUGADJUST(__ct,__fileaddr) \
470 if (n_phdrr->__ct > 0) \ 934 if (n_phdrr->__ct > 0) \
471 { \ 935 { \
472 n_phdrr->__fileaddr += movement; \ 936 n_phdrr->__fileaddr += movement; \
473 } 937 }
474 938
475 if (n == old_mdebug_index) { 939 HDRR * o_phdrr = (HDRR *)((byte *)old_base + OLD_SECTION_H (n).sh_offset);
476 HDRR * o_phdrr = (HDRR *)((byte *)old_base + osec->sh_offset); 940 HDRR * n_phdrr = (HDRR *)((byte *)new_base + NEW_SECTION_H (nn).sh_offset);
477 HDRR * n_phdrr = (HDRR *)((byte *)new_base + nsec->sh_offset); 941 unsigned movement = new_offsets_shift;
478 unsigned movement = new_data2_size;
479 942
480 MDEBUGADJUST (idnMax, cbDnOffset); 943 MDEBUGADJUST (idnMax, cbDnOffset);
481 MDEBUGADJUST (ipdMax, cbPdOffset); 944 MDEBUGADJUST (ipdMax, cbPdOffset);
482 MDEBUGADJUST (isymMax, cbSymOffset); 945 MDEBUGADJUST (isymMax, cbSymOffset);
483 MDEBUGADJUST (ioptMax, cbOptOffset); 946 MDEBUGADJUST (ioptMax, cbOptOffset);
485 MDEBUGADJUST (issMax, cbSsOffset); 948 MDEBUGADJUST (issMax, cbSsOffset);
486 MDEBUGADJUST (issExtMax, cbSsExtOffset); 949 MDEBUGADJUST (issExtMax, cbSsExtOffset);
487 MDEBUGADJUST (ifdMax, cbFdOffset); 950 MDEBUGADJUST (ifdMax, cbFdOffset);
488 MDEBUGADJUST (crfd, cbRfdOffset); 951 MDEBUGADJUST (crfd, cbRfdOffset);
489 MDEBUGADJUST (iextMax, cbExtOffset); 952 MDEBUGADJUST (iextMax, cbExtOffset);
490 953 /* The Line Section, being possible off in a hole of the object,
491 /* The Line Section, being possible off in a hole of the 954 requires special handling. */
492 * object, requires special handling. */ 955 if (n_phdrr->cbLine > 0)
493 if (n_phdrr->cbLine > 0) { 956 {
494 if (o_phdrr->cbLineOffset > 957 if (o_phdrr->cbLineOffset > (OLD_SECTION_H (n).sh_offset
495 osec->sh_offset+ osec->sh_size){ 958 + OLD_SECTION_H (n).sh_size))
496 /* line data is in a hole in elf. do special copy 959 {
497 * and adjust for this ld mistake. */ 960 /* line data is in a hole in elf. do special copy and adjust
961 for this ld mistake.
962 */
498 n_phdrr->cbLineOffset += movement; 963 n_phdrr->cbLineOffset += movement;
499 964
500 memcpy (n_phdrr->cbLineOffset + new_base, 965 memcpy (n_phdrr->cbLineOffset + new_base,
501 o_phdrr->cbLineOffset + old_base, n_phdrr->cbLine); 966 o_phdrr->cbLineOffset + old_base, n_phdrr->cbLine);
502 } else { 967 }
503 /* somehow line data is in .mdebug as it is supposed 968 else
504 * to be. */ 969 {
970 /* somehow line data is in .mdebug as it is supposed to be. */
505 MDEBUGADJUST (cbLine, cbLineOffset); 971 MDEBUGADJUST (cbLine, cbLineOffset);
506 } 972 }
507 } 973 }
508 } 974 }
509 #endif /* __sgi */ 975
510 /* If it is the symbol table, its st_shndx field needs to be 976 /* If it is the symbol table, its st_shndx field needs to be patched. */
511 * patched. */ 977 if (NEW_SECTION_H (nn).sh_type == SHT_SYMTAB
512 if (nsec->sh_type == SHT_SYMTAB || nsec->sh_type == SHT_DYNSYM) { 978 || NEW_SECTION_H (nn).sh_type == SHT_DYNSYM)
513 unsigned int num = nsec->sh_size / nsec->sh_entsize; 979 {
514 ElfW(Sym) * sym = (ElfW(Sym) *)(nsec->sh_offset + new_base); 980 l_Elf_Shdr *spt = &NEW_SECTION_H (nn);
515 byte *symnames = ((byte *) new_base + 981 unsigned int num = spt->sh_size / spt->sh_entsize;
516 NEW_SECTION_H (nsec->sh_link).sh_offset); 982 l_Elf_Sym * sym = (l_Elf_Sym *) (NEW_SECTION_H (nn).sh_offset
517 983 + new_base);
518 for (; num--; sym++) { 984 for (; num--; sym++)
519 const char * symnam = (char *) (symnames + sym->st_name); 985 {
520 986 if (sym->st_shndx == SHN_UNDEF
521 /* Update the symbol values of _edata and _end. */ 987 || sym->st_shndx == SHN_ABS
522 if (strcmp (symnam, "_end") == 0 988 || sym->st_shndx == SHN_COMMON)
523 || strcmp (symnam, "end") == 0 989 continue;
524 || strcmp (symnam, "_edata") == 0 990
525 || strcmp (symnam, "edata") == 0)
526 memcpy (&sym->st_value, &new_bss_addr,sizeof (new_bss_addr));
527
528
529 if ((sym->st_shndx == SHN_UNDEF) || (sym->st_shndx == SHN_ABS)
530 || (sym->st_shndx == SHN_COMMON)
531 || (sym->st_shndx >= SHN_LOPROC &&
532 sym->st_shndx <= SHN_HIPROC))
533 continue;
534
535 PATCH_INDEX (sym->st_shndx); 991 PATCH_INDEX (sym->st_shndx);
536 } 992 }
537 } 993 }
538 } 994 }
539
540 /* This loop seeks out relocation sections for the data section, so
541 * that it can undo relocations performed by the runtime linker. */
542 for (n = new_file_h->e_shnum - 1; n; n--) {
543 ElfW(Shdr) section = NEW_SECTION_H (n);
544
545 if ( section.sh_type == SHT_REL || section.sh_type == SHT_RELA ) {
546 /* This code handles two different size structs, but there
547 * should be no harm in that provided that r_offset is
548 * always the first member. */
549 ElfW(Shdr) * info = & NEW_SECTION_H(section.sh_info);
550 const char * nm = old_section_names + info->sh_name;
551
552 if (!strcmp (nm, ".data") || !strcmp (nm, ".sdata")
553 || !strcmp (nm, ".lit4") || !strcmp (nm, ".lit8")
554 || !strcmp (nm, ".sdata1") || !strcmp (nm, ".data1")) {
555 ElfW(Addr) offset = info->sh_addr - info->sh_offset;
556 caddr_t end, reloc = old_base + section.sh_offset;
557
558 for (end = reloc + section.sh_size; reloc < end;
559 reloc += section.sh_entsize) {
560 ElfW(Addr) addr = ((ElfW(Rel) *) reloc)->r_offset - offset;
561 #ifdef __alpha__
562 /* The Alpha ELF binutils currently have a bug that
563 * sometimes results in relocs that contain all
564 * zeroes. Work around this for now... */
565 if (((ElfW(Rel) *) reloc)->r_offset == 0)
566 continue;
567 #endif
568 memcpy (new_base + addr, old_base + addr,
569 sizeof(ElfW(Addr)));
570 }
571 }
572 }
573 }
574
575 #ifdef UNEXEC_USE_MAP_PRIVATE
576 if (lseek (new_file, 0, SEEK_SET) == -1)
577 fatal ("Can't rewind (%s): errno %d\n", new_name, errno);
578
579 if (write (new_file, new_base, new_file_size) != new_file_size)
580 fatal ("Can't write (%s): errno %d\n", new_name, errno);
581 #endif
582 995
583 /* Close the files and make the new file executable. */ 996 /* Close the files and make the new file executable. */
997
584 if (close (old_file)) 998 if (close (old_file))
585 fatal ("Can't close (%s): errno %d\n", old_name, errno); 999 fatal ("Can't close (%s): errno %d\n", old_name, errno);
586 1000
587 if (close (new_file)) 1001 if (close (new_file))
588 fatal ("Can't close (%s): errno %d\n", new_name, errno); 1002 fatal ("Can't close (%s): errno %d\n", new_name, errno);
589 1003
590 if (stat (new_name, &stat_buf) == -1) 1004 if (stat (new_name, &stat_buf) == -1)
591 fatal ("Can't stat (%s): errno %d\n", new_name, errno); 1005 fatal ("Can't stat (%s): errno %d\n", new_name, errno);
592 1006
593 n = umask (777); 1007 n = umask (777);
594 umask (n); 1008 umask (n);
595 stat_buf.st_mode |= 0111 & ~n; 1009 stat_buf.st_mode |= 0111 & ~n;
596 if (chmod (new_name, stat_buf.st_mode) == -1) 1010 if (chmod (new_name, stat_buf.st_mode) == -1)
597 fatal ("Can't chmod (%s): errno %d\n", new_name, errno); 1011 fatal ("Can't chmod (%s): errno %d\n", new_name, errno);
1012
1013 return 0;
598 } 1014 }