HCoop / bpt / emacs.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
Update years in copyright notice; nfc.
[bpt/emacs.git] / src / unexelf.c
1 /* Copyright (C) 1985, 1986, 1987, 1988, 1990, 1992, 1999, 2000, 2001,
2 2002, 2003, 2004, 2005, 2006 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., 51 Franklin Street, Fifth Floor,
19 Boston, MA 02110-1301, 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, old_name, data_start, bss_start, entry_address)
37 * char *new_name, *old_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 old_name is non-NULL, the symbol table will be taken from the given file.
43 * On some machines, an existing old_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 * Bss_start indicates how much of the data segment is to be saved in the
56 * a.out file and restored when the program is executed. It gives the lowest
57 * unsaved address, and is rounded up to a page boundary. The default when 0
58 * is given assumes that the entire data segment is to be stored, including
59 * the previous data and bss as well as any additional storage allocated with
60 * break (2).
61 *
62 * The new file is set up to start at entry_address.
63 *
64 */
65
66 /* Even more heavily modified by james@bigtex.cactus.org of Dell Computer Co.
67 * ELF support added.
68 *
69 * Basic theory: the data space of the running process needs to be
70 * dumped to the output file. Normally we would just enlarge the size
71 * of .data, scooting everything down. But we can't do that in ELF,
72 * because there is often something between the .data space and the
73 * .bss space.
74 *
75 * In the temacs dump below, notice that the Global Offset Table
76 * (.got) and the Dynamic link data (.dynamic) come between .data1 and
77 * .bss. It does not work to overlap .data with these fields.
78 *
79 * The solution is to create a new .data segment. This segment is
80 * filled with data from the current process. Since the contents of
81 * various sections refer to sections by index, the new .data segment
82 * is made the last in the table to avoid changing any existing index.
83
84 * This is an example of how the section headers are changed. "Addr"
85 * is a process virtual address. "Offset" is a file offset.
86
87 raid:/nfs/raid/src/dist-18.56/src> dump -h temacs
88
89 temacs:
90
91 **** SECTION HEADER TABLE ****
92 [No] Type Flags Addr Offset Size Name
93 Link Info Adralgn Entsize
94
95 [1] 1 2 0x80480d4 0xd4 0x13 .interp
96 0 0 0x1 0
97
98 [2] 5 2 0x80480e8 0xe8 0x388 .hash
99 3 0 0x4 0x4
100
101 [3] 11 2 0x8048470 0x470 0x7f0 .dynsym
102 4 1 0x4 0x10
103
104 [4] 3 2 0x8048c60 0xc60 0x3ad .dynstr
105 0 0 0x1 0
106
107 [5] 9 2 0x8049010 0x1010 0x338 .rel.plt
108 3 7 0x4 0x8
109
110 [6] 1 6 0x8049348 0x1348 0x3 .init
111 0 0 0x4 0
112
113 [7] 1 6 0x804934c 0x134c 0x680 .plt
114 0 0 0x4 0x4
115
116 [8] 1 6 0x80499cc 0x19cc 0x3c56f .text
117 0 0 0x4 0
118
119 [9] 1 6 0x8085f3c 0x3df3c 0x3 .fini
120 0 0 0x4 0
121
122 [10] 1 2 0x8085f40 0x3df40 0x69c .rodata
123 0 0 0x4 0
124
125 [11] 1 2 0x80865dc 0x3e5dc 0xd51 .rodata1
126 0 0 0x4 0
127
128 [12] 1 3 0x8088330 0x3f330 0x20afc .data
129 0 0 0x4 0
130
131 [13] 1 3 0x80a8e2c 0x5fe2c 0x89d .data1
132 0 0 0x4 0
133
134 [14] 1 3 0x80a96cc 0x606cc 0x1a8 .got
135 0 0 0x4 0x4
136
137 [15] 6 3 0x80a9874 0x60874 0x80 .dynamic
138 4 0 0x4 0x8
139
140 [16] 8 3 0x80a98f4 0x608f4 0x449c .bss
141 0 0 0x4 0
142
143 [17] 2 0 0 0x608f4 0x9b90 .symtab
144 18 371 0x4 0x10
145
146 [18] 3 0 0 0x6a484 0x8526 .strtab
147 0 0 0x1 0
148
149 [19] 3 0 0 0x729aa 0x93 .shstrtab
150 0 0 0x1 0
151
152 [20] 1 0 0 0x72a3d 0x68b7 .comment
153 0 0 0x1 0
154
155 raid:/nfs/raid/src/dist-18.56/src> dump -h xemacs
156
157 xemacs:
158
159 **** SECTION HEADER TABLE ****
160 [No] Type Flags Addr Offset Size Name
161 Link Info Adralgn Entsize
162
163 [1] 1 2 0x80480d4 0xd4 0x13 .interp
164 0 0 0x1 0
165
166 [2] 5 2 0x80480e8 0xe8 0x388 .hash
167 3 0 0x4 0x4
168
169 [3] 11 2 0x8048470 0x470 0x7f0 .dynsym
170 4 1 0x4 0x10
171
172 [4] 3 2 0x8048c60 0xc60 0x3ad .dynstr
173 0 0 0x1 0
174
175 [5] 9 2 0x8049010 0x1010 0x338 .rel.plt
176 3 7 0x4 0x8
177
178 [6] 1 6 0x8049348 0x1348 0x3 .init
179 0 0 0x4 0
180
181 [7] 1 6 0x804934c 0x134c 0x680 .plt
182 0 0 0x4 0x4
183
184 [8] 1 6 0x80499cc 0x19cc 0x3c56f .text
185 0 0 0x4 0
186
187 [9] 1 6 0x8085f3c 0x3df3c 0x3 .fini
188 0 0 0x4 0
189
190 [10] 1 2 0x8085f40 0x3df40 0x69c .rodata
191 0 0 0x4 0
192
193 [11] 1 2 0x80865dc 0x3e5dc 0xd51 .rodata1
194 0 0 0x4 0
195
196 [12] 1 3 0x8088330 0x3f330 0x20afc .data
197 0 0 0x4 0
198
199 [13] 1 3 0x80a8e2c 0x5fe2c 0x89d .data1
200 0 0 0x4 0
201
202 [14] 1 3 0x80a96cc 0x606cc 0x1a8 .got
203 0 0 0x4 0x4
204
205 [15] 6 3 0x80a9874 0x60874 0x80 .dynamic
206 4 0 0x4 0x8
207
208 [16] 8 3 0x80c6800 0x7d800 0 .bss
209 0 0 0x4 0
210
211 [17] 2 0 0 0x7d800 0x9b90 .symtab
212 18 371 0x4 0x10
213
214 [18] 3 0 0 0x87390 0x8526 .strtab
215 0 0 0x1 0
216
217 [19] 3 0 0 0x8f8b6 0x93 .shstrtab
218 0 0 0x1 0
219
220 [20] 1 0 0 0x8f949 0x68b7 .comment
221 0 0 0x1 0
222
223 [21] 1 3 0x80a98f4 0x608f4 0x1cf0c .data
224 0 0 0x4 0
225
226 * This is an example of how the file header is changed. "Shoff" is
227 * the section header offset within the file. Since that table is
228 * after the new .data section, it is moved. "Shnum" is the number of
229 * sections, which we increment.
230 *
231 * "Phoff" is the file offset to the program header. "Phentsize" and
232 * "Shentsz" are the program and section header entries sizes respectively.
233 * These can be larger than the apparent struct sizes.
234
235 raid:/nfs/raid/src/dist-18.56/src> dump -f temacs
236
237 temacs:
238
239 **** ELF HEADER ****
240 Class Data Type Machine Version
241 Entry Phoff Shoff Flags Ehsize
242 Phentsize Phnum Shentsz Shnum Shstrndx
243
244 1 1 2 3 1
245 0x80499cc 0x34 0x792f4 0 0x34
246 0x20 5 0x28 21 19
247
248 raid:/nfs/raid/src/dist-18.56/src> dump -f xemacs
249
250 xemacs:
251
252 **** ELF HEADER ****
253 Class Data Type Machine Version
254 Entry Phoff Shoff Flags Ehsize
255 Phentsize Phnum Shentsz Shnum Shstrndx
256
257 1 1 2 3 1
258 0x80499cc 0x34 0x96200 0 0x34
259 0x20 5 0x28 22 19
260
261 * These are the program headers. "Offset" is the file offset to the
262 * segment. "Vaddr" is the memory load address. "Filesz" is the
263 * segment size as it appears in the file, and "Memsz" is the size in
264 * memory. Below, the third segment is the code and the fourth is the
265 * data: the difference between Filesz and Memsz is .bss
266
267 raid:/nfs/raid/src/dist-18.56/src> dump -o temacs
268
269 temacs:
270 ***** PROGRAM EXECUTION HEADER *****
271 Type Offset Vaddr Paddr
272 Filesz Memsz Flags Align
273
274 6 0x34 0x8048034 0
275 0xa0 0xa0 5 0
276
277 3 0xd4 0 0
278 0x13 0 4 0
279
280 1 0x34 0x8048034 0
281 0x3f2f9 0x3f2f9 5 0x1000
282
283 1 0x3f330 0x8088330 0
284 0x215c4 0x25a60 7 0x1000
285
286 2 0x60874 0x80a9874 0
287 0x80 0 7 0
288
289 raid:/nfs/raid/src/dist-18.56/src> dump -o xemacs
290
291 xemacs:
292 ***** PROGRAM EXECUTION HEADER *****
293 Type Offset Vaddr Paddr
294 Filesz Memsz Flags Align
295
296 6 0x34 0x8048034 0
297 0xa0 0xa0 5 0
298
299 3 0xd4 0 0
300 0x13 0 4 0
301
302 1 0x34 0x8048034 0
303 0x3f2f9 0x3f2f9 5 0x1000
304
305 1 0x3f330 0x8088330 0
306 0x3e4d0 0x3e4d0 7 0x1000
307
308 2 0x60874 0x80a9874 0
309 0x80 0 7 0
310
311
312 */
313 \f
314 /* Modified by wtien@urbana.mcd.mot.com of Motorola Inc.
315 *
316 * The above mechanism does not work if the unexeced ELF file is being
317 * re-layout by other applications (such as `strip'). All the applications
318 * that re-layout the internal of ELF will layout all sections in ascending
319 * order of their file offsets. After the re-layout, the data2 section will
320 * still be the LAST section in the section header vector, but its file offset
321 * is now being pushed far away down, and causes part of it not to be mapped
322 * in (ie. not covered by the load segment entry in PHDR vector), therefore
323 * causes the new binary to fail.
324 *
325 * The solution is to modify the unexec algorithm to insert the new data2
326 * section header right before the new bss section header, so their file
327 * offsets will be in the ascending order. Since some of the section's (all
328 * sections AFTER the bss section) indexes are now changed, we also need to
329 * modify some fields to make them point to the right sections. This is done
330 * by macro PATCH_INDEX. All the fields that need to be patched are:
331 *
332 * 1. ELF header e_shstrndx field.
333 * 2. section header sh_link and sh_info field.
334 * 3. symbol table entry st_shndx field.
335 *
336 * The above example now should look like:
337
338 **** SECTION HEADER TABLE ****
339 [No] Type Flags Addr Offset Size Name
340 Link Info Adralgn Entsize
341
342 [1] 1 2 0x80480d4 0xd4 0x13 .interp
343 0 0 0x1 0
344
345 [2] 5 2 0x80480e8 0xe8 0x388 .hash
346 3 0 0x4 0x4
347
348 [3] 11 2 0x8048470 0x470 0x7f0 .dynsym
349 4 1 0x4 0x10
350
351 [4] 3 2 0x8048c60 0xc60 0x3ad .dynstr
352 0 0 0x1 0
353
354 [5] 9 2 0x8049010 0x1010 0x338 .rel.plt
355 3 7 0x4 0x8
356
357 [6] 1 6 0x8049348 0x1348 0x3 .init
358 0 0 0x4 0
359
360 [7] 1 6 0x804934c 0x134c 0x680 .plt
361 0 0 0x4 0x4
362
363 [8] 1 6 0x80499cc 0x19cc 0x3c56f .text
364 0 0 0x4 0
365
366 [9] 1 6 0x8085f3c 0x3df3c 0x3 .fini
367 0 0 0x4 0
368
369 [10] 1 2 0x8085f40 0x3df40 0x69c .rodata
370 0 0 0x4 0
371
372 [11] 1 2 0x80865dc 0x3e5dc 0xd51 .rodata1
373 0 0 0x4 0
374
375 [12] 1 3 0x8088330 0x3f330 0x20afc .data
376 0 0 0x4 0
377
378 [13] 1 3 0x80a8e2c 0x5fe2c 0x89d .data1
379 0 0 0x4 0
380
381 [14] 1 3 0x80a96cc 0x606cc 0x1a8 .got
382 0 0 0x4 0x4
383
384 [15] 6 3 0x80a9874 0x60874 0x80 .dynamic
385 4 0 0x4 0x8
386
387 [16] 1 3 0x80a98f4 0x608f4 0x1cf0c .data
388 0 0 0x4 0
389
390 [17] 8 3 0x80c6800 0x7d800 0 .bss
391 0 0 0x4 0
392
393 [18] 2 0 0 0x7d800 0x9b90 .symtab
394 19 371 0x4 0x10
395
396 [19] 3 0 0 0x87390 0x8526 .strtab
397 0 0 0x1 0
398
399 [20] 3 0 0 0x8f8b6 0x93 .shstrtab
400 0 0 0x1 0
401
402 [21] 1 0 0 0x8f949 0x68b7 .comment
403 0 0 0x1 0
404
405 */
406 \f
407 /* We do not use mmap because that fails with NFS.
408 Instead we read the whole file, modify it, and write it out. */
409
410 #ifndef emacs
411 #define fatal(a, b, c) fprintf (stderr, a, b, c), exit (1)
412 #include <string.h>
413 #else
414 #include <config.h>
415 extern void fatal (const char *msgid, ...);
416 #endif
417
418 #include <sys/types.h>
419 #include <stdio.h>
420 #include <sys/stat.h>
421 #include <memory.h>
422 #include <errno.h>
423 #include <unistd.h>
424 #include <fcntl.h>
425 #if !defined (__NetBSD__) && !defined (__OpenBSD__)
426 #include <elf.h>
427 #endif
428 #include <sys/mman.h>
429 #if defined (__sony_news) && defined (_SYSTYPE_SYSV)
430 #include <sys/elf_mips.h>
431 #include <sym.h>
432 #endif /* __sony_news && _SYSTYPE_SYSV */
433 #if __sgi
434 #include <syms.h> /* for HDRR declaration */
435 #endif /* __sgi */
436
437 #ifndef MAP_ANON
438 #ifdef MAP_ANONYMOUS
439 #define MAP_ANON MAP_ANONYMOUS
440 #else
441 #define MAP_ANON 0
442 #endif
443 #endif
444
445 #ifndef MAP_FAILED
446 #define MAP_FAILED ((void *) -1)
447 #endif
448
449 #if defined (__alpha__) && !defined (__NetBSD__) && !defined (__OpenBSD__)
450 /* Declare COFF debugging symbol table. This used to be in
451 /usr/include/sym.h, but this file is no longer included in Red Hat
452 5.0 and presumably in any other glibc 2.x based distribution. */
453 typedef struct {
454 short magic;
455 short vstamp;
456 int ilineMax;
457 int idnMax;
458 int ipdMax;
459 int isymMax;
460 int ioptMax;
461 int iauxMax;
462 int issMax;
463 int issExtMax;
464 int ifdMax;
465 int crfd;
466 int iextMax;
467 long cbLine;
468 long cbLineOffset;
469 long cbDnOffset;
470 long cbPdOffset;
471 long cbSymOffset;
472 long cbOptOffset;
473 long cbAuxOffset;
474 long cbSsOffset;
475 long cbSsExtOffset;
476 long cbFdOffset;
477 long cbRfdOffset;
478 long cbExtOffset;
479 } HDRR, *pHDRR;
480 #define cbHDRR sizeof(HDRR)
481 #define hdrNil ((pHDRR)0)
482 #endif
483
484 #ifdef __NetBSD__
485 /*
486 * NetBSD does not have normal-looking user-land ELF support.
487 */
488 # if defined __alpha__ || defined __sparc_v9__
489 # define ELFSIZE 64
490 # else
491 # define ELFSIZE 32
492 # endif
493 # include <sys/exec_elf.h>
494
495 # ifndef PT_LOAD
496 # define PT_LOAD Elf_pt_load
497 # if 0 /* was in pkgsrc patches for 20.7 */
498 # define SHT_PROGBITS Elf_sht_progbits
499 # endif
500 # define SHT_SYMTAB Elf_sht_symtab
501 # define SHT_DYNSYM Elf_sht_dynsym
502 # define SHT_NULL Elf_sht_null
503 # define SHT_NOBITS Elf_sht_nobits
504 # define SHT_REL Elf_sht_rel
505 # define SHT_RELA Elf_sht_rela
506
507 # define SHN_UNDEF Elf_eshn_undefined
508 # define SHN_ABS Elf_eshn_absolute
509 # define SHN_COMMON Elf_eshn_common
510 # endif /* !PT_LOAD */
511
512 # ifdef __alpha__
513 # include <sys/exec_ecoff.h>
514 # define HDRR struct ecoff_symhdr
515 # define pHDRR HDRR *
516 # endif /* __alpha__ */
517
518 #ifdef __mips__ /* was in pkgsrc patches for 20.7 */
519 # define SHT_MIPS_DEBUG DT_MIPS_FLAGS
520 # define HDRR struct Elf_Shdr
521 #endif /* __mips__ */
522 #endif /* __NetBSD__ */
523
524 #ifdef __OpenBSD__
525 # include <sys/exec_elf.h>
526 #endif
527
528 #if __GNU_LIBRARY__ - 0 >= 6
529 # include <link.h> /* get ElfW etc */
530 #endif
531
532 #ifndef ElfW
533 # ifdef __STDC__
534 # define ElfBitsW(bits, type) Elf##bits##_##type
535 # else
536 # define ElfBitsW(bits, type) Elf/**/bits/**/_/**/type
537 # endif
538 # ifdef _LP64
539 # define ELFSIZE 64
540 # else
541 # define ELFSIZE 32
542 # endif
543 /* This macro expands `bits' before invoking ElfBitsW. */
544 # define ElfExpandBitsW(bits, type) ElfBitsW (bits, type)
545 # define ElfW(type) ElfExpandBitsW (ELFSIZE, type)
546 #endif
547
548 #ifndef ELF_BSS_SECTION_NAME
549 #define ELF_BSS_SECTION_NAME ".bss"
550 #endif
551
552 /* Get the address of a particular section or program header entry,
553 * accounting for the size of the entries.
554 */
555 /*
556 On PPC Reference Platform running Solaris 2.5.1
557 the plt section is also of type NOBI like the bss section.
558 (not really stored) and therefore sections after the bss
559 section start at the plt offset. The plt section is always
560 the one just before the bss section.
561 Thus, we modify the test from
562 if (NEW_SECTION_H (nn).sh_offset >= new_data2_offset)
563 to
564 if (NEW_SECTION_H (nn).sh_offset >=
565 OLD_SECTION_H (old_bss_index-1).sh_offset)
566 This is just a hack. We should put the new data section
567 before the .plt section.
568 And we should not have this routine at all but use
569 the libelf library to read the old file and create the new
570 file.
571 The changed code is minimal and depends on prep set in m/prep.h
572 Erik Deumens
573 Quantum Theory Project
574 University of Florida
575 deumens@qtp.ufl.edu
576 Apr 23, 1996
577 */
578
579 #define OLD_SECTION_H(n) \
580 (*(ElfW(Shdr) *) ((byte *) old_section_h + old_file_h->e_shentsize * (n)))
581 #define NEW_SECTION_H(n) \
582 (*(ElfW(Shdr) *) ((byte *) new_section_h + new_file_h->e_shentsize * (n)))
583 #define OLD_PROGRAM_H(n) \
584 (*(ElfW(Phdr) *) ((byte *) old_program_h + old_file_h->e_phentsize * (n)))
585 #define NEW_PROGRAM_H(n) \
586 (*(ElfW(Phdr) *) ((byte *) new_program_h + new_file_h->e_phentsize * (n)))
587
588 #define PATCH_INDEX(n) \
589 do { \
590 if ((int) (n) >= old_bss_index) \
591 (n)++; } while (0)
592 typedef unsigned char byte;
593
594 /* Round X up to a multiple of Y. */
595
596 static ElfW(Addr)
597 round_up (x, y)
598 ElfW(Addr) x, y;
599 {
600 int rem = x % y;
601 if (rem == 0)
602 return x;
603 return x - rem + y;
604 }
605
606 /* Return the index of the section named NAME.
607 SECTION_NAMES, FILE_NAME and FILE_H give information
608 about the file we are looking in.
609
610 If we don't find the section NAME, that is a fatal error
611 if NOERROR is 0; we return -1 if NOERROR is nonzero. */
612
613 static int
614 find_section (name, section_names, file_name, old_file_h, old_section_h, noerror)
615 char *name;
616 char *section_names;
617 char *file_name;
618 ElfW(Ehdr) *old_file_h;
619 ElfW(Shdr) *old_section_h;
620 int noerror;
621 {
622 int idx;
623
624 for (idx = 1; idx < old_file_h->e_shnum; idx++)
625 {
626 #ifdef DEBUG
627 fprintf (stderr, "Looking for %s - found %s\n", name,
628 section_names + OLD_SECTION_H (idx).sh_name);
629 #endif
630 if (!strcmp (section_names + OLD_SECTION_H (idx).sh_name,
631 name))
632 break;
633 }
634 if (idx == old_file_h->e_shnum)
635 {
636 if (noerror)
637 return -1;
638 else
639 fatal ("Can't find %s in %s.\n", name, file_name);
640 }
641
642 return idx;
643 }
644
645 /* ****************************************************************
646 * unexec
647 *
648 * driving logic.
649 *
650 * In ELF, this works by replacing the old .bss section with a new
651 * .data section, and inserting an empty .bss immediately afterwards.
652 *
653 */
654 void
655 unexec (new_name, old_name, data_start, bss_start, entry_address)
656 char *new_name, *old_name;
657 unsigned data_start, bss_start, entry_address;
658 {
659 int new_file, old_file, new_file_size;
660
661 /* Pointers to the base of the image of the two files. */
662 caddr_t old_base, new_base;
663
664 #if MAP_ANON == 0
665 int mmap_fd;
666 #else
667 # define mmap_fd -1
668 #endif
669
670 /* Pointers to the file, program and section headers for the old and
671 new files. */
672 ElfW(Ehdr) *old_file_h, *new_file_h;
673 ElfW(Phdr) *old_program_h, *new_program_h;
674 ElfW(Shdr) *old_section_h, *new_section_h;
675
676 /* Point to the section name table in the old file. */
677 char *old_section_names;
678
679 ElfW(Addr) old_bss_addr, new_bss_addr;
680 ElfW(Word) old_bss_size, new_data2_size;
681 ElfW(Off) new_data2_offset;
682 ElfW(Addr) new_data2_addr;
683
684 int n, nn;
685 int old_bss_index, old_sbss_index, old_plt_index;
686 int old_data_index, new_data2_index;
687 int old_mdebug_index;
688 struct stat stat_buf;
689 int old_file_size;
690
691 /* Open the old file, allocate a buffer of the right size, and read
692 in the file contents. */
693
694 old_file = open (old_name, O_RDONLY);
695
696 if (old_file < 0)
697 fatal ("Can't open %s for reading: errno %d\n", old_name, errno);
698
699 if (fstat (old_file, &stat_buf) == -1)
700 fatal ("Can't fstat (%s): errno %d\n", old_name, errno);
701
702 #if MAP_ANON == 0
703 mmap_fd = open ("/dev/zero", O_RDONLY);
704 if (mmap_fd < 0)
705 fatal ("Can't open /dev/zero for reading: errno %d\n", errno, 0);
706 #endif
707
708 /* We cannot use malloc here because that may use sbrk. If it does,
709 we'd dump our temporary buffers with Emacs, and we'd have to be
710 extra careful to use the correct value of sbrk(0) after
711 allocating all buffers in the code below, which we aren't. */
712 old_file_size = stat_buf.st_size;
713 old_base = mmap (NULL, old_file_size, PROT_READ | PROT_WRITE,
714 MAP_ANON | MAP_PRIVATE, mmap_fd, 0);
715 if (old_base == MAP_FAILED)
716 fatal ("Can't allocate buffer for %s\n", old_name, 0);
717
718 if (read (old_file, old_base, stat_buf.st_size) != stat_buf.st_size)
719 fatal ("Didn't read all of %s: errno %d\n", old_name, errno);
720
721 /* Get pointers to headers & section names */
722
723 old_file_h = (ElfW(Ehdr) *) old_base;
724 old_program_h = (ElfW(Phdr) *) ((byte *) old_base + old_file_h->e_phoff);
725 old_section_h = (ElfW(Shdr) *) ((byte *) old_base + old_file_h->e_shoff);
726 old_section_names = (char *) old_base
727 + OLD_SECTION_H (old_file_h->e_shstrndx).sh_offset;
728
729 /* Find the mdebug section, if any. */
730
731 old_mdebug_index = find_section (".mdebug", old_section_names,
732 old_name, old_file_h, old_section_h, 1);
733
734 /* Find the old .bss section. Figure out parameters of the new
735 data2 and bss sections. */
736
737 old_bss_index = find_section (".bss", old_section_names,
738 old_name, old_file_h, old_section_h, 0);
739
740 old_sbss_index = find_section (".sbss", old_section_names,
741 old_name, old_file_h, old_section_h, 1);
742 if (old_sbss_index != -1)
743 if (OLD_SECTION_H (old_sbss_index).sh_type != SHT_NOBITS)
744 old_sbss_index = -1;
745
746 /* PowerPC64 has .plt in the BSS section. */
747 old_plt_index = find_section (".plt", old_section_names,
748 old_name, old_file_h, old_section_h, 1);
749 if (old_plt_index != -1)
750 if (OLD_SECTION_H (old_plt_index).sh_type != SHT_NOBITS)
751 old_plt_index = -1;
752
753 if (old_sbss_index == -1 && old_plt_index == -1)
754 {
755 old_bss_addr = OLD_SECTION_H (old_bss_index).sh_addr;
756 old_bss_size = OLD_SECTION_H (old_bss_index).sh_size;
757 new_data2_index = old_bss_index;
758 }
759 else if (old_plt_index != -1
760 && (old_sbss_index == -1
761 || (OLD_SECTION_H (old_sbss_index).sh_addr
762 > OLD_SECTION_H (old_plt_index).sh_addr)))
763 {
764 old_bss_addr = OLD_SECTION_H (old_plt_index).sh_addr;
765 old_bss_size = OLD_SECTION_H (old_bss_index).sh_size
766 + OLD_SECTION_H (old_plt_index).sh_size;
767 if (old_sbss_index != -1)
768 old_bss_size += OLD_SECTION_H (old_sbss_index).sh_size;
769 new_data2_index = old_plt_index;
770 }
771 else
772 {
773 old_bss_addr = OLD_SECTION_H (old_sbss_index).sh_addr;
774 old_bss_size = OLD_SECTION_H (old_bss_index).sh_size
775 + OLD_SECTION_H (old_sbss_index).sh_size;
776 new_data2_index = old_sbss_index;
777 }
778
779 /* Find the old .data section. Figure out parameters of
780 the new data2 and bss sections. */
781
782 old_data_index = find_section (".data", old_section_names,
783 old_name, old_file_h, old_section_h, 0);
784
785 #if defined (emacs) || !defined (DEBUG)
786 new_bss_addr = (ElfW(Addr)) sbrk (0);
787 #else
788 new_bss_addr = old_bss_addr + old_bss_size + 0x1234;
789 #endif
790 new_data2_addr = old_bss_addr;
791 new_data2_size = new_bss_addr - old_bss_addr;
792 new_data2_offset = OLD_SECTION_H (old_data_index).sh_offset +
793 (new_data2_addr - OLD_SECTION_H (old_data_index).sh_addr);
794
795 #ifdef DEBUG
796 fprintf (stderr, "old_bss_index %d\n", old_bss_index);
797 fprintf (stderr, "old_bss_addr %x\n", old_bss_addr);
798 fprintf (stderr, "old_bss_size %x\n", old_bss_size);
799 fprintf (stderr, "new_bss_addr %x\n", new_bss_addr);
800 fprintf (stderr, "new_data2_addr %x\n", new_data2_addr);
801 fprintf (stderr, "new_data2_size %x\n", new_data2_size);
802 fprintf (stderr, "new_data2_offset %x\n", new_data2_offset);
803 #endif
804
805 if ((unsigned) new_bss_addr < (unsigned) old_bss_addr + old_bss_size)
806 fatal (".bss shrank when undumping???\n", 0, 0);
807
808 /* Set the output file to the right size. Allocate a buffer to hold
809 the image of the new file. Set pointers to various interesting
810 objects. stat_buf still has old_file data. */
811
812 new_file = open (new_name, O_RDWR | O_CREAT, 0666);
813 if (new_file < 0)
814 fatal ("Can't creat (%s): errno %d\n", new_name, errno);
815
816 new_file_size = stat_buf.st_size + old_file_h->e_shentsize + new_data2_size;
817
818 if (ftruncate (new_file, new_file_size))
819 fatal ("Can't ftruncate (%s): errno %d\n", new_name, errno);
820
821 new_base = mmap (NULL, new_file_size, PROT_READ | PROT_WRITE,
822 MAP_ANON | MAP_PRIVATE, mmap_fd, 0);
823 if (new_base == MAP_FAILED)
824 fatal ("Can't allocate buffer for %s\n", old_name, 0);
825
826 new_file_h = (ElfW(Ehdr) *) new_base;
827 new_program_h = (ElfW(Phdr) *) ((byte *) new_base + old_file_h->e_phoff);
828 new_section_h = (ElfW(Shdr) *)
829 ((byte *) new_base + old_file_h->e_shoff + new_data2_size);
830
831 /* Make our new file, program and section headers as copies of the
832 originals. */
833
834 memcpy (new_file_h, old_file_h, old_file_h->e_ehsize);
835 memcpy (new_program_h, old_program_h,
836 old_file_h->e_phnum * old_file_h->e_phentsize);
837
838 /* Modify the e_shstrndx if necessary. */
839 PATCH_INDEX (new_file_h->e_shstrndx);
840
841 /* Fix up file header. We'll add one section. Section header is
842 further away now. */
843
844 new_file_h->e_shoff += new_data2_size;
845 new_file_h->e_shnum += 1;
846
847 #ifdef DEBUG
848 fprintf (stderr, "Old section offset %x\n", old_file_h->e_shoff);
849 fprintf (stderr, "Old section count %d\n", old_file_h->e_shnum);
850 fprintf (stderr, "New section offset %x\n", new_file_h->e_shoff);
851 fprintf (stderr, "New section count %d\n", new_file_h->e_shnum);
852 #endif
853
854 /* Fix up a new program header. Extend the writable data segment so
855 that the bss area is covered too. Find that segment by looking
856 for a segment that ends just before the .bss area. Make sure
857 that no segments are above the new .data2. Put a loop at the end
858 to adjust the offset and address of any segment that is above
859 data2, just in case we decide to allow this later. */
860
861 for (n = new_file_h->e_phnum - 1; n >= 0; n--)
862 {
863 /* Compute maximum of all requirements for alignment of section. */
864 ElfW(Word) alignment = (NEW_PROGRAM_H (n)).p_align;
865 if ((OLD_SECTION_H (old_bss_index)).sh_addralign > alignment)
866 alignment = OLD_SECTION_H (old_bss_index).sh_addralign;
867
868 #ifdef __sgi
869 /* According to r02kar@x4u2.desy.de (Karsten Kuenne)
870 and oliva@gnu.org (Alexandre Oliva), on IRIX 5.2, we
871 always get "Program segment above .bss" when dumping
872 when the executable doesn't have an sbss section. */
873 if (old_sbss_index != -1)
874 #endif /* __sgi */
875 if (NEW_PROGRAM_H (n).p_vaddr + NEW_PROGRAM_H (n).p_filesz
876 > (old_sbss_index == -1
877 ? old_bss_addr
878 : round_up (old_bss_addr, alignment)))
879 fatal ("Program segment above .bss in %s\n", old_name, 0);
880
881 if (NEW_PROGRAM_H (n).p_type == PT_LOAD
882 && (round_up ((NEW_PROGRAM_H (n)).p_vaddr
883 + (NEW_PROGRAM_H (n)).p_filesz,
884 alignment)
885 == round_up (old_bss_addr, alignment)))
886 break;
887 }
888 if (n < 0)
889 fatal ("Couldn't find segment next to .bss in %s\n", old_name, 0);
890
891 /* Make sure that the size includes any padding before the old .bss
892 section. */
893 NEW_PROGRAM_H (n).p_filesz = new_bss_addr - NEW_PROGRAM_H (n).p_vaddr;
894 NEW_PROGRAM_H (n).p_memsz = NEW_PROGRAM_H (n).p_filesz;
895
896 #if 0 /* Maybe allow section after data2 - does this ever happen? */
897 for (n = new_file_h->e_phnum - 1; n >= 0; n--)
898 {
899 if (NEW_PROGRAM_H (n).p_vaddr
900 && NEW_PROGRAM_H (n).p_vaddr >= new_data2_addr)
901 NEW_PROGRAM_H (n).p_vaddr += new_data2_size - old_bss_size;
902
903 if (NEW_PROGRAM_H (n).p_offset >= new_data2_offset)
904 NEW_PROGRAM_H (n).p_offset += new_data2_size;
905 }
906 #endif
907
908 /* Fix up section headers based on new .data2 section. Any section
909 whose offset or virtual address is after the new .data2 section
910 gets its value adjusted. .bss size becomes zero and new address
911 is set. data2 section header gets added by copying the existing
912 .data header and modifying the offset, address and size. */
913 for (old_data_index = 1; old_data_index < (int) old_file_h->e_shnum;
914 old_data_index++)
915 if (!strcmp (old_section_names + OLD_SECTION_H (old_data_index).sh_name,
916 ".data"))
917 break;
918 if (old_data_index == old_file_h->e_shnum)
919 fatal ("Can't find .data in %s.\n", old_name, 0);
920
921 /* Walk through all section headers, insert the new data2 section right
922 before the new bss section. */
923 for (n = 1, nn = 1; n < (int) old_file_h->e_shnum; n++, nn++)
924 {
925 caddr_t src;
926 /* If it is (s)bss section, insert the new data2 section before it. */
927 /* new_data2_index is the index of either old_sbss or old_bss, that was
928 chosen as a section for new_data2. */
929 if (n == new_data2_index)
930 {
931 /* Steal the data section header for this data2 section. */
932 memcpy (&NEW_SECTION_H (nn), &OLD_SECTION_H (old_data_index),
933 new_file_h->e_shentsize);
934
935 NEW_SECTION_H (nn).sh_addr = new_data2_addr;
936 NEW_SECTION_H (nn).sh_offset = new_data2_offset;
937 NEW_SECTION_H (nn).sh_size = new_data2_size;
938 /* Use the bss section's alignment. This will assure that the
939 new data2 section always be placed in the same spot as the old
940 bss section by any other application. */
941 NEW_SECTION_H (nn).sh_addralign = OLD_SECTION_H (n).sh_addralign;
942
943 /* Now copy over what we have in the memory now. */
944 memcpy (NEW_SECTION_H (nn).sh_offset + new_base,
945 (caddr_t) OLD_SECTION_H (n).sh_addr,
946 new_data2_size);
947 nn++;
948 }
949
950 memcpy (&NEW_SECTION_H (nn), &OLD_SECTION_H (n),
951 old_file_h->e_shentsize);
952
953 if (n == old_bss_index
954 /* The new bss and sbss section's size is zero, and its file offset
955 and virtual address should be off by NEW_DATA2_SIZE. */
956 || n == old_sbss_index || n == old_plt_index
957 )
958 {
959 /* NN should be `old_s?bss_index + 1' at this point. */
960 NEW_SECTION_H (nn).sh_offset =
961 NEW_SECTION_H (new_data2_index).sh_offset + new_data2_size;
962 NEW_SECTION_H (nn).sh_addr =
963 NEW_SECTION_H (new_data2_index).sh_addr + new_data2_size;
964 /* Let the new bss section address alignment be the same as the
965 section address alignment followed the old bss section, so
966 this section will be placed in exactly the same place. */
967 NEW_SECTION_H (nn).sh_addralign = OLD_SECTION_H (nn).sh_addralign;
968 NEW_SECTION_H (nn).sh_size = 0;
969 }
970 else
971 {
972 /* Any section that was originally placed after the .bss
973 section should now be off by NEW_DATA2_SIZE. If a
974 section overlaps the .bss section, consider it to be
975 placed after the .bss section. Overlap can occur if the
976 section just before .bss has less-strict alignment; this
977 was observed between .symtab and .bss on Solaris 2.5.1
978 (sparc) with GCC snapshot 960602. */
979 #ifdef SOLARIS_POWERPC
980 /* On PPC Reference Platform running Solaris 2.5.1
981 the plt section is also of type NOBI like the bss section.
982 (not really stored) and therefore sections after the bss
983 section start at the plt offset. The plt section is always
984 the one just before the bss section.
985 It would be better to put the new data section before
986 the .plt section, or use libelf instead.
987 Erik Deumens, deumens@qtp.ufl.edu. */
988 if (NEW_SECTION_H (nn).sh_offset
989 >= OLD_SECTION_H (old_bss_index-1).sh_offset)
990 NEW_SECTION_H (nn).sh_offset += new_data2_size;
991 #else
992 if (NEW_SECTION_H (nn).sh_offset + NEW_SECTION_H (nn).sh_size
993 > new_data2_offset)
994 NEW_SECTION_H (nn).sh_offset += new_data2_size;
995 #endif
996 /* Any section that was originally placed after the section
997 header table should now be off by the size of one section
998 header table entry. */
999 if (NEW_SECTION_H (nn).sh_offset > new_file_h->e_shoff)
1000 NEW_SECTION_H (nn).sh_offset += new_file_h->e_shentsize;
1001 }
1002
1003 /* If any section hdr refers to the section after the new .data
1004 section, make it refer to next one because we have inserted
1005 a new section in between. */
1006
1007 PATCH_INDEX (NEW_SECTION_H (nn).sh_link);
1008 /* For symbol tables, info is a symbol table index,
1009 so don't change it. */
1010 if (NEW_SECTION_H (nn).sh_type != SHT_SYMTAB
1011 && NEW_SECTION_H (nn).sh_type != SHT_DYNSYM)
1012 PATCH_INDEX (NEW_SECTION_H (nn).sh_info);
1013
1014 if (old_sbss_index != -1)
1015 if (!strcmp (old_section_names + NEW_SECTION_H (nn).sh_name, ".sbss"))
1016 {
1017 NEW_SECTION_H (nn).sh_offset =
1018 round_up (NEW_SECTION_H (nn).sh_offset,
1019 NEW_SECTION_H (nn).sh_addralign);
1020 NEW_SECTION_H (nn).sh_type = SHT_PROGBITS;
1021 }
1022
1023 /* Now, start to copy the content of sections. */
1024 if (NEW_SECTION_H (nn).sh_type == SHT_NULL
1025 || NEW_SECTION_H (nn).sh_type == SHT_NOBITS)
1026 continue;
1027
1028 /* Write out the sections. .data and .data1 (and data2, called
1029 ".data" in the strings table) get copied from the current process
1030 instead of the old file. */
1031 if (!strcmp (old_section_names + NEW_SECTION_H (n).sh_name, ".data")
1032 || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name),
1033 ".sdata")
1034 || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name),
1035 ".lit4")
1036 || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name),
1037 ".lit8")
1038 /* The conditional bit below was in Oliva's original code
1039 (1999-08-25) and seems to have been dropped by mistake
1040 subsequently. It prevents a crash at startup under X in
1041 `IRIX64 6.5 6.5.17m', whether compiled on that relase or
1042 an earlier one. It causes no trouble on the other ELF
1043 platforms I could test (Irix 6.5.15m, Solaris 8, Debian
1044 Potato x86, Debian Woody SPARC); however, it's reported
1045 to cause crashes under some version of GNU/Linux. It's
1046 not yet clear what's changed in that Irix version to
1047 cause the problem, or why the fix sometimes fails under
1048 GNU/Linux. There's probably no good reason to have
1049 something Irix-specific here, but this will have to do
1050 for now. IRIX6_5 is the most specific macro we have to
1051 test. -- fx 2002-10-01
1052
1053 The issue _looks_ as though it's gone away on 6.5.18m,
1054 but maybe it's still lurking, to be triggered by some
1055 change in the binary. It appears to concern the dynamic
1056 loader, but I never got anywhere with an SGI support call
1057 seeking clues. -- fx 2002-11-29. */
1058 #ifdef IRIX6_5
1059 || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name),
1060 ".got")
1061 #endif
1062 || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name),
1063 ".sdata1")
1064 || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name),
1065 ".data1")
1066 || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name),
1067 ".sbss"))
1068 src = (caddr_t) OLD_SECTION_H (n).sh_addr;
1069 else
1070 src = old_base + OLD_SECTION_H (n).sh_offset;
1071
1072 memcpy (NEW_SECTION_H (nn).sh_offset + new_base, src,
1073 NEW_SECTION_H (nn).sh_size);
1074
1075 #ifdef __alpha__
1076 /* Update Alpha COFF symbol table: */
1077 if (strcmp (old_section_names + OLD_SECTION_H (n).sh_name, ".mdebug")
1078 == 0)
1079 {
1080 pHDRR symhdr = (pHDRR) (NEW_SECTION_H (nn).sh_offset + new_base);
1081
1082 symhdr->cbLineOffset += new_data2_size;
1083 symhdr->cbDnOffset += new_data2_size;
1084 symhdr->cbPdOffset += new_data2_size;
1085 symhdr->cbSymOffset += new_data2_size;
1086 symhdr->cbOptOffset += new_data2_size;
1087 symhdr->cbAuxOffset += new_data2_size;
1088 symhdr->cbSsOffset += new_data2_size;
1089 symhdr->cbSsExtOffset += new_data2_size;
1090 symhdr->cbFdOffset += new_data2_size;
1091 symhdr->cbRfdOffset += new_data2_size;
1092 symhdr->cbExtOffset += new_data2_size;
1093 }
1094 #endif /* __alpha__ */
1095
1096 #if defined (__sony_news) && defined (_SYSTYPE_SYSV)
1097 if (NEW_SECTION_H (nn).sh_type == SHT_MIPS_DEBUG
1098 && old_mdebug_index != -1)
1099 {
1100 int diff = NEW_SECTION_H(nn).sh_offset
1101 - OLD_SECTION_H(old_mdebug_index).sh_offset;
1102 HDRR *phdr = (HDRR *)(NEW_SECTION_H (nn).sh_offset + new_base);
1103
1104 if (diff)
1105 {
1106 phdr->cbLineOffset += diff;
1107 phdr->cbDnOffset += diff;
1108 phdr->cbPdOffset += diff;
1109 phdr->cbSymOffset += diff;
1110 phdr->cbOptOffset += diff;
1111 phdr->cbAuxOffset += diff;
1112 phdr->cbSsOffset += diff;
1113 phdr->cbSsExtOffset += diff;
1114 phdr->cbFdOffset += diff;
1115 phdr->cbRfdOffset += diff;
1116 phdr->cbExtOffset += diff;
1117 }
1118 }
1119 #endif /* __sony_news && _SYSTYPE_SYSV */
1120
1121 #if __sgi
1122 /* Adjust the HDRR offsets in .mdebug and copy the
1123 line data if it's in its usual 'hole' in the object.
1124 Makes the new file debuggable with dbx.
1125 patches up two problems: the absolute file offsets
1126 in the HDRR record of .mdebug (see /usr/include/syms.h), and
1127 the ld bug that gets the line table in a hole in the
1128 elf file rather than in the .mdebug section proper.
1129 David Anderson. davea@sgi.com Jan 16,1994. */
1130 if (n == old_mdebug_index)
1131 {
1132 #define MDEBUGADJUST(__ct,__fileaddr) \
1133 if (n_phdrr->__ct > 0) \
1134 { \
1135 n_phdrr->__fileaddr += movement; \
1136 }
1137
1138 HDRR * o_phdrr = (HDRR *)((byte *)old_base + OLD_SECTION_H (n).sh_offset);
1139 HDRR * n_phdrr = (HDRR *)((byte *)new_base + NEW_SECTION_H (nn).sh_offset);
1140 unsigned movement = new_data2_size;
1141
1142 MDEBUGADJUST (idnMax, cbDnOffset);
1143 MDEBUGADJUST (ipdMax, cbPdOffset);
1144 MDEBUGADJUST (isymMax, cbSymOffset);
1145 MDEBUGADJUST (ioptMax, cbOptOffset);
1146 MDEBUGADJUST (iauxMax, cbAuxOffset);
1147 MDEBUGADJUST (issMax, cbSsOffset);
1148 MDEBUGADJUST (issExtMax, cbSsExtOffset);
1149 MDEBUGADJUST (ifdMax, cbFdOffset);
1150 MDEBUGADJUST (crfd, cbRfdOffset);
1151 MDEBUGADJUST (iextMax, cbExtOffset);
1152 /* The Line Section, being possible off in a hole of the object,
1153 requires special handling. */
1154 if (n_phdrr->cbLine > 0)
1155 {
1156 if (o_phdrr->cbLineOffset > (OLD_SECTION_H (n).sh_offset
1157 + OLD_SECTION_H (n).sh_size))
1158 {
1159 /* line data is in a hole in elf. do special copy and adjust
1160 for this ld mistake.
1161 */
1162 n_phdrr->cbLineOffset += movement;
1163
1164 memcpy (n_phdrr->cbLineOffset + new_base,
1165 o_phdrr->cbLineOffset + old_base, n_phdrr->cbLine);
1166 }
1167 else
1168 {
1169 /* somehow line data is in .mdebug as it is supposed to be. */
1170 MDEBUGADJUST (cbLine, cbLineOffset);
1171 }
1172 }
1173 }
1174 #endif /* __sgi */
1175
1176 /* If it is the symbol table, its st_shndx field needs to be patched. */
1177 if (NEW_SECTION_H (nn).sh_type == SHT_SYMTAB
1178 || NEW_SECTION_H (nn).sh_type == SHT_DYNSYM)
1179 {
1180 ElfW(Shdr) *spt = &NEW_SECTION_H (nn);
1181 unsigned int num = spt->sh_size / spt->sh_entsize;
1182 ElfW(Sym) * sym = (ElfW(Sym) *) (NEW_SECTION_H (nn).sh_offset +
1183 new_base);
1184 for (; num--; sym++)
1185 {
1186 if ((sym->st_shndx == SHN_UNDEF)
1187 || (sym->st_shndx == SHN_ABS)
1188 || (sym->st_shndx == SHN_COMMON))
1189 continue;
1190
1191 PATCH_INDEX (sym->st_shndx);
1192 }
1193 }
1194 }
1195
1196 /* Update the symbol values of _edata and _end. */
1197 for (n = new_file_h->e_shnum - 1; n; n--)
1198 {
1199 byte *symnames;
1200 ElfW(Sym) *symp, *symendp;
1201
1202 if (NEW_SECTION_H (n).sh_type != SHT_DYNSYM
1203 && NEW_SECTION_H (n).sh_type != SHT_SYMTAB)
1204 continue;
1205
1206 symnames = ((byte *) new_base
1207 + NEW_SECTION_H (NEW_SECTION_H (n).sh_link).sh_offset);
1208 symp = (ElfW(Sym) *) (NEW_SECTION_H (n).sh_offset + new_base);
1209 symendp = (ElfW(Sym) *) ((byte *)symp + NEW_SECTION_H (n).sh_size);
1210
1211 for (; symp < symendp; symp ++)
1212 if (strcmp ((char *) (symnames + symp->st_name), "_end") == 0
1213 || strcmp ((char *) (symnames + symp->st_name), "end") == 0
1214 || strcmp ((char *) (symnames + symp->st_name), "_edata") == 0
1215 || strcmp ((char *) (symnames + symp->st_name), "edata") == 0)
1216 memcpy (&symp->st_value, &new_bss_addr, sizeof (new_bss_addr));
1217 }
1218
1219 /* This loop seeks out relocation sections for the data section, so
1220 that it can undo relocations performed by the runtime linker. */
1221 for (n = new_file_h->e_shnum - 1; n; n--)
1222 {
1223 ElfW(Shdr) section = NEW_SECTION_H (n);
1224
1225 /* Cause a compilation error if anyone uses n instead of nn below. */
1226 struct {int a;} n;
1227 (void)n.a; /* Prevent `unused variable' warnings. */
1228
1229 switch (section.sh_type)
1230 {
1231 default:
1232 break;
1233 case SHT_REL:
1234 case SHT_RELA:
1235 /* This code handles two different size structs, but there should
1236 be no harm in that provided that r_offset is always the first
1237 member. */
1238 nn = section.sh_info;
1239 if (!strcmp (old_section_names + NEW_SECTION_H (nn).sh_name, ".data")
1240 || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name),
1241 ".sdata")
1242 || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name),
1243 ".lit4")
1244 || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name),
1245 ".lit8")
1246 #ifdef IRIX6_5 /* see above */
1247 || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name),
1248 ".got")
1249 #endif
1250 || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name),
1251 ".sdata1")
1252 || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name),
1253 ".data1"))
1254 {
1255 ElfW(Addr) offset = (NEW_SECTION_H (nn).sh_addr
1256 - NEW_SECTION_H (nn).sh_offset);
1257 caddr_t reloc = old_base + section.sh_offset, end;
1258 for (end = reloc + section.sh_size; reloc < end;
1259 reloc += section.sh_entsize)
1260 {
1261 ElfW(Addr) addr = ((ElfW(Rel) *) reloc)->r_offset - offset;
1262 #ifdef __alpha__
1263 /* The Alpha ELF binutils currently have a bug that
1264 sometimes results in relocs that contain all
1265 zeroes. Work around this for now... */
1266 if (((ElfW(Rel) *) reloc)->r_offset == 0)
1267 continue;
1268 #endif
1269 memcpy (new_base + addr, old_base + addr, sizeof(ElfW(Addr)));
1270 }
1271 }
1272 break;
1273 }
1274 }
1275
1276 /* Write out new_file, and free the buffers. */
1277
1278 if (write (new_file, new_base, new_file_size) != new_file_size)
1279 #ifndef emacs
1280 fatal ("Didn't write %d bytes: errno %d\n",
1281 new_file_size, errno);
1282 #else
1283 fatal ("Didn't write %d bytes to %s: errno %d\n",
1284 new_file_size, new_base, errno);
1285 #endif
1286 munmap (old_base, old_file_size);
1287 munmap (new_base, new_file_size);
1288
1289 /* Close the files and make the new file executable. */
1290
1291 #if MAP_ANON == 0
1292 close (mmap_fd);
1293 #endif
1294
1295 if (close (old_file))
1296 fatal ("Can't close (%s): errno %d\n", old_name, errno);
1297
1298 if (close (new_file))
1299 fatal ("Can't close (%s): errno %d\n", new_name, errno);
1300
1301 if (stat (new_name, &stat_buf) == -1)
1302 fatal ("Can't stat (%s): errno %d\n", new_name, errno);
1303
1304 n = umask (777);
1305 umask (n);
1306 stat_buf.st_mode |= 0111 & ~n;
1307 if (chmod (new_name, stat_buf.st_mode) == -1)
1308 fatal ("Can't chmod (%s): errno %d\n", new_name, errno);
1309 }
1310
1311 /* arch-tag: e02e1512-95e2-4ef0-bba7-b6bce658f1e3
1312 (do not change this comment) */
Unnamed repository; edit this file 'description' to name the repository.