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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 #ifdef BROKEN_NOCOMBRELOC
437 #include <assert.h>
438 #endif
439
440 #ifndef MAP_ANON
441 #ifdef MAP_ANONYMOUS
442 #define MAP_ANON MAP_ANONYMOUS
443 #else
444 #define MAP_ANON 0
445 #endif
446 #endif
447
448 #ifndef MAP_FAILED
449 #define MAP_FAILED ((void *) -1)
450 #endif
451
452 #if defined (__alpha__) && !defined (__NetBSD__) && !defined (__OpenBSD__)
453 /* Declare COFF debugging symbol table. This used to be in
454 /usr/include/sym.h, but this file is no longer included in Red Hat
455 5.0 and presumably in any other glibc 2.x based distribution. */
456 typedef struct {
457 short magic;
458 short vstamp;
459 int ilineMax;
460 int idnMax;
461 int ipdMax;
462 int isymMax;
463 int ioptMax;
464 int iauxMax;
465 int issMax;
466 int issExtMax;
467 int ifdMax;
468 int crfd;
469 int iextMax;
470 long cbLine;
471 long cbLineOffset;
472 long cbDnOffset;
473 long cbPdOffset;
474 long cbSymOffset;
475 long cbOptOffset;
476 long cbAuxOffset;
477 long cbSsOffset;
478 long cbSsExtOffset;
479 long cbFdOffset;
480 long cbRfdOffset;
481 long cbExtOffset;
482 } HDRR, *pHDRR;
483 #define cbHDRR sizeof(HDRR)
484 #define hdrNil ((pHDRR)0)
485 #endif
486
487 #ifdef __NetBSD__
488 /*
489 * NetBSD does not have normal-looking user-land ELF support.
490 */
491 # if defined __alpha__ || defined __sparc_v9__
492 # define ELFSIZE 64
493 # else
494 # define ELFSIZE 32
495 # endif
496 # include <sys/exec_elf.h>
497
498 # ifndef PT_LOAD
499 # define PT_LOAD Elf_pt_load
500 # if 0 /* was in pkgsrc patches for 20.7 */
501 # define SHT_PROGBITS Elf_sht_progbits
502 # endif
503 # define SHT_SYMTAB Elf_sht_symtab
504 # define SHT_DYNSYM Elf_sht_dynsym
505 # define SHT_NULL Elf_sht_null
506 # define SHT_NOBITS Elf_sht_nobits
507 # define SHT_REL Elf_sht_rel
508 # define SHT_RELA Elf_sht_rela
509
510 # define SHN_UNDEF Elf_eshn_undefined
511 # define SHN_ABS Elf_eshn_absolute
512 # define SHN_COMMON Elf_eshn_common
513 # endif /* !PT_LOAD */
514
515 # ifdef __alpha__
516 # include <sys/exec_ecoff.h>
517 # define HDRR struct ecoff_symhdr
518 # define pHDRR HDRR *
519 # endif /* __alpha__ */
520
521 #ifdef __mips__ /* was in pkgsrc patches for 20.7 */
522 # define SHT_MIPS_DEBUG DT_MIPS_FLAGS
523 # define HDRR struct Elf_Shdr
524 #endif /* __mips__ */
525 #endif /* __NetBSD__ */
526
527 #ifdef __OpenBSD__
528 # include <sys/exec_elf.h>
529 #endif
530
531 #if __GNU_LIBRARY__ - 0 >= 6
532 # include <link.h> /* get ElfW etc */
533 #endif
534
535 #ifndef ElfW
536 # ifdef __STDC__
537 # define ElfBitsW(bits, type) Elf##bits##_##type
538 # else
539 # define ElfBitsW(bits, type) Elf/**/bits/**/_/**/type
540 # endif
541 # ifdef _LP64
542 # define ELFSIZE 64
543 # else
544 # define ELFSIZE 32
545 # endif
546 /* This macro expands `bits' before invoking ElfBitsW. */
547 # define ElfExpandBitsW(bits, type) ElfBitsW (bits, type)
548 # define ElfW(type) ElfExpandBitsW (ELFSIZE, type)
549 #endif
550
551 #ifndef ELF_BSS_SECTION_NAME
552 #define ELF_BSS_SECTION_NAME ".bss"
553 #endif
554
555 /* Get the address of a particular section or program header entry,
556 * accounting for the size of the entries.
557 */
558 /*
559 On PPC Reference Platform running Solaris 2.5.1
560 the plt section is also of type NOBI like the bss section.
561 (not really stored) and therefore sections after the bss
562 section start at the plt offset. The plt section is always
563 the one just before the bss section.
564 Thus, we modify the test from
565 if (NEW_SECTION_H (nn).sh_offset >= new_data2_offset)
566 to
567 if (NEW_SECTION_H (nn).sh_offset >=
568 OLD_SECTION_H (old_bss_index-1).sh_offset)
569 This is just a hack. We should put the new data section
570 before the .plt section.
571 And we should not have this routine at all but use
572 the libelf library to read the old file and create the new
573 file.
574 The changed code is minimal and depends on prep set in m/prep.h
575 Erik Deumens
576 Quantum Theory Project
577 University of Florida
578 deumens@qtp.ufl.edu
579 Apr 23, 1996
580 */
581
582 #define OLD_SECTION_H(n) \
583 (*(ElfW(Shdr) *) ((byte *) old_section_h + old_file_h->e_shentsize * (n)))
584 #define NEW_SECTION_H(n) \
585 (*(ElfW(Shdr) *) ((byte *) new_section_h + new_file_h->e_shentsize * (n)))
586 #define OLD_PROGRAM_H(n) \
587 (*(ElfW(Phdr) *) ((byte *) old_program_h + old_file_h->e_phentsize * (n)))
588 #define NEW_PROGRAM_H(n) \
589 (*(ElfW(Phdr) *) ((byte *) new_program_h + new_file_h->e_phentsize * (n)))
590
591 #define PATCH_INDEX(n) \
592 do { \
593 if ((int) (n) >= old_bss_index) \
594 (n)++; } while (0)
595 typedef unsigned char byte;
596
597 /* Round X up to a multiple of Y. */
598
599 static ElfW(Addr)
600 round_up (x, y)
601 ElfW(Addr) x, y;
602 {
603 int rem = x % y;
604 if (rem == 0)
605 return x;
606 return x - rem + y;
607 }
608
609 /* Return the index of the section named NAME.
610 SECTION_NAMES, FILE_NAME and FILE_H give information
611 about the file we are looking in.
612
613 If we don't find the section NAME, that is a fatal error
614 if NOERROR is 0; we return -1 if NOERROR is nonzero. */
615
616 static int
617 find_section (name, section_names, file_name, old_file_h, old_section_h, noerror)
618 char *name;
619 char *section_names;
620 char *file_name;
621 ElfW(Ehdr) *old_file_h;
622 ElfW(Shdr) *old_section_h;
623 int noerror;
624 {
625 int idx;
626
627 for (idx = 1; idx < old_file_h->e_shnum; idx++)
628 {
629 #ifdef DEBUG
630 fprintf (stderr, "Looking for %s - found %s\n", name,
631 section_names + OLD_SECTION_H (idx).sh_name);
632 #endif
633 if (!strcmp (section_names + OLD_SECTION_H (idx).sh_name,
634 name))
635 break;
636 }
637 if (idx == old_file_h->e_shnum)
638 {
639 if (noerror)
640 return -1;
641 else
642 fatal ("Can't find %s in %s.\n", name, file_name);
643 }
644
645 return idx;
646 }
647
648 /* ****************************************************************
649 * unexec
650 *
651 * driving logic.
652 *
653 * In ELF, this works by replacing the old .bss section with a new
654 * .data section, and inserting an empty .bss immediately afterwards.
655 *
656 */
657 void
658 unexec (new_name, old_name, data_start, bss_start, entry_address)
659 char *new_name, *old_name;
660 unsigned data_start, bss_start, entry_address;
661 {
662 int new_file, old_file, new_file_size;
663
664 /* Pointers to the base of the image of the two files. */
665 caddr_t old_base, new_base;
666
667 #if MAP_ANON == 0
668 int mmap_fd;
669 #else
670 # define mmap_fd -1
671 #endif
672
673 /* Pointers to the file, program and section headers for the old and
674 new files. */
675 ElfW(Ehdr) *old_file_h, *new_file_h;
676 ElfW(Phdr) *old_program_h, *new_program_h;
677 ElfW(Shdr) *old_section_h, *new_section_h;
678
679 /* Point to the section name table in the old file. */
680 char *old_section_names;
681
682 ElfW(Addr) old_bss_addr, new_bss_addr;
683 ElfW(Word) old_bss_size, new_data2_size;
684 ElfW(Off) new_data2_offset;
685 ElfW(Addr) new_data2_addr;
686
687 int n, nn;
688 int old_bss_index, old_sbss_index, old_plt_index;
689 int old_data_index, new_data2_index;
690 int old_mdebug_index;
691 struct stat stat_buf;
692 int old_file_size;
693 #ifdef BROKEN_NOCOMBRELOC
694 int unreloc_sections[10], n_unreloc_sections;
695 #endif
696
697 /* Open the old file, allocate a buffer of the right size, and read
698 in the file contents. */
699
700 old_file = open (old_name, O_RDONLY);
701
702 if (old_file < 0)
703 fatal ("Can't open %s for reading: errno %d\n", old_name, errno);
704
705 if (fstat (old_file, &stat_buf) == -1)
706 fatal ("Can't fstat (%s): errno %d\n", old_name, errno);
707
708 #if MAP_ANON == 0
709 mmap_fd = open ("/dev/zero", O_RDONLY);
710 if (mmap_fd < 0)
711 fatal ("Can't open /dev/zero for reading: errno %d\n", errno, 0);
712 #endif
713
714 /* We cannot use malloc here because that may use sbrk. If it does,
715 we'd dump our temporary buffers with Emacs, and we'd have to be
716 extra careful to use the correct value of sbrk(0) after
717 allocating all buffers in the code below, which we aren't. */
718 old_file_size = stat_buf.st_size;
719 old_base = mmap (NULL, old_file_size, PROT_READ | PROT_WRITE,
720 MAP_ANON | MAP_PRIVATE, mmap_fd, 0);
721 if (old_base == MAP_FAILED)
722 fatal ("Can't allocate buffer for %s\n", old_name, 0);
723
724 if (read (old_file, old_base, stat_buf.st_size) != stat_buf.st_size)
725 fatal ("Didn't read all of %s: errno %d\n", old_name, errno);
726
727 /* Get pointers to headers & section names */
728
729 old_file_h = (ElfW(Ehdr) *) old_base;
730 old_program_h = (ElfW(Phdr) *) ((byte *) old_base + old_file_h->e_phoff);
731 old_section_h = (ElfW(Shdr) *) ((byte *) old_base + old_file_h->e_shoff);
732 old_section_names = (char *) old_base
733 + OLD_SECTION_H (old_file_h->e_shstrndx).sh_offset;
734
735 /* Find the mdebug section, if any. */
736
737 old_mdebug_index = find_section (".mdebug", old_section_names,
738 old_name, old_file_h, old_section_h, 1);
739
740 /* Find the old .bss section. Figure out parameters of the new
741 data2 and bss sections. */
742
743 old_bss_index = find_section (".bss", old_section_names,
744 old_name, old_file_h, old_section_h, 0);
745
746 old_sbss_index = find_section (".sbss", old_section_names,
747 old_name, old_file_h, old_section_h, 1);
748 if (old_sbss_index != -1)
749 if (OLD_SECTION_H (old_sbss_index).sh_type != SHT_NOBITS)
750 old_sbss_index = -1;
751
752 /* PowerPC64 has .plt in the BSS section. */
753 old_plt_index = find_section (".plt", old_section_names,
754 old_name, old_file_h, old_section_h, 1);
755 if (old_plt_index != -1)
756 if (OLD_SECTION_H (old_plt_index).sh_type != SHT_NOBITS)
757 old_plt_index = -1;
758
759 if (old_sbss_index == -1 && old_plt_index == -1)
760 {
761 old_bss_addr = OLD_SECTION_H (old_bss_index).sh_addr;
762 old_bss_size = OLD_SECTION_H (old_bss_index).sh_size;
763 new_data2_index = old_bss_index;
764 }
765 else if (old_plt_index != -1
766 && (old_sbss_index == -1
767 || (OLD_SECTION_H (old_sbss_index).sh_addr
768 > OLD_SECTION_H (old_plt_index).sh_addr)))
769 {
770 old_bss_addr = OLD_SECTION_H (old_plt_index).sh_addr;
771 old_bss_size = OLD_SECTION_H (old_bss_index).sh_size
772 + OLD_SECTION_H (old_plt_index).sh_size;
773 if (old_sbss_index != -1)
774 old_bss_size += OLD_SECTION_H (old_sbss_index).sh_size;
775 new_data2_index = old_plt_index;
776 }
777 else
778 {
779 old_bss_addr = OLD_SECTION_H (old_sbss_index).sh_addr;
780 old_bss_size = OLD_SECTION_H (old_bss_index).sh_size
781 + OLD_SECTION_H (old_sbss_index).sh_size;
782 new_data2_index = old_sbss_index;
783 }
784
785 /* Find the old .data section. Figure out parameters of
786 the new data2 and bss sections. */
787
788 old_data_index = find_section (".data", old_section_names,
789 old_name, old_file_h, old_section_h, 0);
790
791 #if defined (emacs) || !defined (DEBUG)
792 new_bss_addr = (ElfW(Addr)) sbrk (0);
793 #else
794 new_bss_addr = old_bss_addr + old_bss_size + 0x1234;
795 #endif
796 new_data2_addr = old_bss_addr;
797 new_data2_size = new_bss_addr - old_bss_addr;
798 new_data2_offset = OLD_SECTION_H (old_data_index).sh_offset +
799 (new_data2_addr - OLD_SECTION_H (old_data_index).sh_addr);
800
801 #ifdef DEBUG
802 fprintf (stderr, "old_bss_index %d\n", old_bss_index);
803 fprintf (stderr, "old_bss_addr %x\n", old_bss_addr);
804 fprintf (stderr, "old_bss_size %x\n", old_bss_size);
805 fprintf (stderr, "new_bss_addr %x\n", new_bss_addr);
806 fprintf (stderr, "new_data2_addr %x\n", new_data2_addr);
807 fprintf (stderr, "new_data2_size %x\n", new_data2_size);
808 fprintf (stderr, "new_data2_offset %x\n", new_data2_offset);
809 #endif
810
811 if ((unsigned) new_bss_addr < (unsigned) old_bss_addr + old_bss_size)
812 fatal (".bss shrank when undumping???\n", 0, 0);
813
814 /* Set the output file to the right size. Allocate a buffer to hold
815 the image of the new file. Set pointers to various interesting
816 objects. stat_buf still has old_file data. */
817
818 new_file = open (new_name, O_RDWR | O_CREAT, 0666);
819 if (new_file < 0)
820 fatal ("Can't creat (%s): errno %d\n", new_name, errno);
821
822 new_file_size = stat_buf.st_size + old_file_h->e_shentsize + new_data2_size;
823
824 if (ftruncate (new_file, new_file_size))
825 fatal ("Can't ftruncate (%s): errno %d\n", new_name, errno);
826
827 new_base = mmap (NULL, new_file_size, PROT_READ | PROT_WRITE,
828 MAP_ANON | MAP_PRIVATE, mmap_fd, 0);
829 if (new_base == MAP_FAILED)
830 fatal ("Can't allocate buffer for %s\n", old_name, 0);
831
832 new_file_h = (ElfW(Ehdr) *) new_base;
833 new_program_h = (ElfW(Phdr) *) ((byte *) new_base + old_file_h->e_phoff);
834 new_section_h = (ElfW(Shdr) *)
835 ((byte *) new_base + old_file_h->e_shoff + new_data2_size);
836
837 /* Make our new file, program and section headers as copies of the
838 originals. */
839
840 memcpy (new_file_h, old_file_h, old_file_h->e_ehsize);
841 memcpy (new_program_h, old_program_h,
842 old_file_h->e_phnum * old_file_h->e_phentsize);
843
844 /* Modify the e_shstrndx if necessary. */
845 PATCH_INDEX (new_file_h->e_shstrndx);
846
847 /* Fix up file header. We'll add one section. Section header is
848 further away now. */
849
850 new_file_h->e_shoff += new_data2_size;
851 new_file_h->e_shnum += 1;
852
853 #ifdef DEBUG
854 fprintf (stderr, "Old section offset %x\n", old_file_h->e_shoff);
855 fprintf (stderr, "Old section count %d\n", old_file_h->e_shnum);
856 fprintf (stderr, "New section offset %x\n", new_file_h->e_shoff);
857 fprintf (stderr, "New section count %d\n", new_file_h->e_shnum);
858 #endif
859
860 /* Fix up a new program header. Extend the writable data segment so
861 that the bss area is covered too. Find that segment by looking
862 for a segment that ends just before the .bss area. Make sure
863 that no segments are above the new .data2. Put a loop at the end
864 to adjust the offset and address of any segment that is above
865 data2, just in case we decide to allow this later. */
866
867 for (n = new_file_h->e_phnum - 1; n >= 0; n--)
868 {
869 /* Compute maximum of all requirements for alignment of section. */
870 ElfW(Word) alignment = (NEW_PROGRAM_H (n)).p_align;
871 if ((OLD_SECTION_H (old_bss_index)).sh_addralign > alignment)
872 alignment = OLD_SECTION_H (old_bss_index).sh_addralign;
873
874 #ifdef __sgi
875 /* According to r02kar@x4u2.desy.de (Karsten Kuenne)
876 and oliva@gnu.org (Alexandre Oliva), on IRIX 5.2, we
877 always get "Program segment above .bss" when dumping
878 when the executable doesn't have an sbss section. */
879 if (old_sbss_index != -1)
880 #endif /* __sgi */
881 if (NEW_PROGRAM_H (n).p_vaddr + NEW_PROGRAM_H (n).p_filesz
882 > (old_sbss_index == -1
883 ? old_bss_addr
884 : round_up (old_bss_addr, alignment)))
885 fatal ("Program segment above .bss in %s\n", old_name, 0);
886
887 if (NEW_PROGRAM_H (n).p_type == PT_LOAD
888 && (round_up ((NEW_PROGRAM_H (n)).p_vaddr
889 + (NEW_PROGRAM_H (n)).p_filesz,
890 alignment)
891 == round_up (old_bss_addr, alignment)))
892 break;
893 }
894 if (n < 0)
895 fatal ("Couldn't find segment next to .bss in %s\n", old_name, 0);
896
897 /* Make sure that the size includes any padding before the old .bss
898 section. */
899 NEW_PROGRAM_H (n).p_filesz = new_bss_addr - NEW_PROGRAM_H (n).p_vaddr;
900 NEW_PROGRAM_H (n).p_memsz = NEW_PROGRAM_H (n).p_filesz;
901
902 #if 0 /* Maybe allow section after data2 - does this ever happen? */
903 for (n = new_file_h->e_phnum - 1; n >= 0; n--)
904 {
905 if (NEW_PROGRAM_H (n).p_vaddr
906 && NEW_PROGRAM_H (n).p_vaddr >= new_data2_addr)
907 NEW_PROGRAM_H (n).p_vaddr += new_data2_size - old_bss_size;
908
909 if (NEW_PROGRAM_H (n).p_offset >= new_data2_offset)
910 NEW_PROGRAM_H (n).p_offset += new_data2_size;
911 }
912 #endif
913
914 /* Fix up section headers based on new .data2 section. Any section
915 whose offset or virtual address is after the new .data2 section
916 gets its value adjusted. .bss size becomes zero and new address
917 is set. data2 section header gets added by copying the existing
918 .data header and modifying the offset, address and size. */
919 for (old_data_index = 1; old_data_index < (int) old_file_h->e_shnum;
920 old_data_index++)
921 if (!strcmp (old_section_names + OLD_SECTION_H (old_data_index).sh_name,
922 ".data"))
923 break;
924 if (old_data_index == old_file_h->e_shnum)
925 fatal ("Can't find .data in %s.\n", old_name, 0);
926
927 /* Walk through all section headers, insert the new data2 section right
928 before the new bss section. */
929 for (n = 1, nn = 1; n < (int) old_file_h->e_shnum; n++, nn++)
930 {
931 caddr_t src;
932 /* If it is (s)bss section, insert the new data2 section before it. */
933 /* new_data2_index is the index of either old_sbss or old_bss, that was
934 chosen as a section for new_data2. */
935 if (n == new_data2_index)
936 {
937 /* Steal the data section header for this data2 section. */
938 memcpy (&NEW_SECTION_H (nn), &OLD_SECTION_H (old_data_index),
939 new_file_h->e_shentsize);
940
941 NEW_SECTION_H (nn).sh_addr = new_data2_addr;
942 NEW_SECTION_H (nn).sh_offset = new_data2_offset;
943 NEW_SECTION_H (nn).sh_size = new_data2_size;
944 /* Use the bss section's alignment. This will assure that the
945 new data2 section always be placed in the same spot as the old
946 bss section by any other application. */
947 NEW_SECTION_H (nn).sh_addralign = OLD_SECTION_H (n).sh_addralign;
948
949 /* Now copy over what we have in the memory now. */
950 memcpy (NEW_SECTION_H (nn).sh_offset + new_base,
951 (caddr_t) OLD_SECTION_H (n).sh_addr,
952 new_data2_size);
953 nn++;
954 }
955
956 memcpy (&NEW_SECTION_H (nn), &OLD_SECTION_H (n),
957 old_file_h->e_shentsize);
958
959 if (n == old_bss_index
960 /* The new bss and sbss section's size is zero, and its file offset
961 and virtual address should be off by NEW_DATA2_SIZE. */
962 || n == old_sbss_index || n == old_plt_index
963 )
964 {
965 /* NN should be `old_s?bss_index + 1' at this point. */
966 NEW_SECTION_H (nn).sh_offset =
967 NEW_SECTION_H (new_data2_index).sh_offset + new_data2_size;
968 NEW_SECTION_H (nn).sh_addr =
969 NEW_SECTION_H (new_data2_index).sh_addr + new_data2_size;
970 /* Let the new bss section address alignment be the same as the
971 section address alignment followed the old bss section, so
972 this section will be placed in exactly the same place. */
973 NEW_SECTION_H (nn).sh_addralign = OLD_SECTION_H (nn).sh_addralign;
974 NEW_SECTION_H (nn).sh_size = 0;
975 }
976 else
977 {
978 /* Any section that was originally placed after the .bss
979 section should now be off by NEW_DATA2_SIZE. If a
980 section overlaps the .bss section, consider it to be
981 placed after the .bss section. Overlap can occur if the
982 section just before .bss has less-strict alignment; this
983 was observed between .symtab and .bss on Solaris 2.5.1
984 (sparc) with GCC snapshot 960602. */
985 #ifdef SOLARIS_POWERPC
986 /* On PPC Reference Platform running Solaris 2.5.1
987 the plt section is also of type NOBI like the bss section.
988 (not really stored) and therefore sections after the bss
989 section start at the plt offset. The plt section is always
990 the one just before the bss section.
991 It would be better to put the new data section before
992 the .plt section, or use libelf instead.
993 Erik Deumens, deumens@qtp.ufl.edu. */
994 if (NEW_SECTION_H (nn).sh_offset
995 >= OLD_SECTION_H (old_bss_index-1).sh_offset)
996 NEW_SECTION_H (nn).sh_offset += new_data2_size;
997 #else
998 if (NEW_SECTION_H (nn).sh_offset + NEW_SECTION_H (nn).sh_size
999 > new_data2_offset)
1000 NEW_SECTION_H (nn).sh_offset += new_data2_size;
1001 #endif
1002 /* Any section that was originally placed after the section
1003 header table should now be off by the size of one section
1004 header table entry. */
1005 if (NEW_SECTION_H (nn).sh_offset > new_file_h->e_shoff)
1006 NEW_SECTION_H (nn).sh_offset += new_file_h->e_shentsize;
1007 }
1008
1009 /* If any section hdr refers to the section after the new .data
1010 section, make it refer to next one because we have inserted
1011 a new section in between. */
1012
1013 PATCH_INDEX (NEW_SECTION_H (nn).sh_link);
1014 /* For symbol tables, info is a symbol table index,
1015 so don't change it. */
1016 if (NEW_SECTION_H (nn).sh_type != SHT_SYMTAB
1017 && NEW_SECTION_H (nn).sh_type != SHT_DYNSYM)
1018 PATCH_INDEX (NEW_SECTION_H (nn).sh_info);
1019
1020 if (old_sbss_index != -1)
1021 if (!strcmp (old_section_names + NEW_SECTION_H (nn).sh_name, ".sbss"))
1022 {
1023 NEW_SECTION_H (nn).sh_offset =
1024 round_up (NEW_SECTION_H (nn).sh_offset,
1025 NEW_SECTION_H (nn).sh_addralign);
1026 NEW_SECTION_H (nn).sh_type = SHT_PROGBITS;
1027 }
1028
1029 /* Now, start to copy the content of sections. */
1030 if (NEW_SECTION_H (nn).sh_type == SHT_NULL
1031 || NEW_SECTION_H (nn).sh_type == SHT_NOBITS)
1032 continue;
1033
1034 /* Write out the sections. .data and .data1 (and data2, called
1035 ".data" in the strings table) get copied from the current process
1036 instead of the old file. */
1037 if (!strcmp (old_section_names + NEW_SECTION_H (n).sh_name, ".data")
1038 || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name),
1039 ".sdata")
1040 || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name),
1041 ".lit4")
1042 || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name),
1043 ".lit8")
1044 /* The conditional bit below was in Oliva's original code
1045 (1999-08-25) and seems to have been dropped by mistake
1046 subsequently. It prevents a crash at startup under X in
1047 `IRIX64 6.5 6.5.17m', whether compiled on that relase or
1048 an earlier one. It causes no trouble on the other ELF
1049 platforms I could test (Irix 6.5.15m, Solaris 8, Debian
1050 Potato x86, Debian Woody SPARC); however, it's reported
1051 to cause crashes under some version of GNU/Linux. It's
1052 not yet clear what's changed in that Irix version to
1053 cause the problem, or why the fix sometimes fails under
1054 GNU/Linux. There's probably no good reason to have
1055 something Irix-specific here, but this will have to do
1056 for now. IRIX6_5 is the most specific macro we have to
1057 test. -- fx 2002-10-01
1058
1059 The issue _looks_ as though it's gone away on 6.5.18m,
1060 but maybe it's still lurking, to be triggered by some
1061 change in the binary. It appears to concern the dynamic
1062 loader, but I never got anywhere with an SGI support call
1063 seeking clues. -- fx 2002-11-29. */
1064 #ifdef IRIX6_5
1065 || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name),
1066 ".got")
1067 #endif
1068 || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name),
1069 ".sdata1")
1070 || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name),
1071 ".data1")
1072 || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name),
1073 ".sbss"))
1074 src = (caddr_t) OLD_SECTION_H (n).sh_addr;
1075 else
1076 src = old_base + OLD_SECTION_H (n).sh_offset;
1077
1078 memcpy (NEW_SECTION_H (nn).sh_offset + new_base, src,
1079 NEW_SECTION_H (nn).sh_size);
1080
1081 #ifdef __alpha__
1082 /* Update Alpha COFF symbol table: */
1083 if (strcmp (old_section_names + OLD_SECTION_H (n).sh_name, ".mdebug")
1084 == 0)
1085 {
1086 pHDRR symhdr = (pHDRR) (NEW_SECTION_H (nn).sh_offset + new_base);
1087
1088 symhdr->cbLineOffset += new_data2_size;
1089 symhdr->cbDnOffset += new_data2_size;
1090 symhdr->cbPdOffset += new_data2_size;
1091 symhdr->cbSymOffset += new_data2_size;
1092 symhdr->cbOptOffset += new_data2_size;
1093 symhdr->cbAuxOffset += new_data2_size;
1094 symhdr->cbSsOffset += new_data2_size;
1095 symhdr->cbSsExtOffset += new_data2_size;
1096 symhdr->cbFdOffset += new_data2_size;
1097 symhdr->cbRfdOffset += new_data2_size;
1098 symhdr->cbExtOffset += new_data2_size;
1099 }
1100 #endif /* __alpha__ */
1101
1102 #if defined (__sony_news) && defined (_SYSTYPE_SYSV)
1103 if (NEW_SECTION_H (nn).sh_type == SHT_MIPS_DEBUG
1104 && old_mdebug_index != -1)
1105 {
1106 int diff = NEW_SECTION_H(nn).sh_offset
1107 - OLD_SECTION_H(old_mdebug_index).sh_offset;
1108 HDRR *phdr = (HDRR *)(NEW_SECTION_H (nn).sh_offset + new_base);
1109
1110 if (diff)
1111 {
1112 phdr->cbLineOffset += diff;
1113 phdr->cbDnOffset += diff;
1114 phdr->cbPdOffset += diff;
1115 phdr->cbSymOffset += diff;
1116 phdr->cbOptOffset += diff;
1117 phdr->cbAuxOffset += diff;
1118 phdr->cbSsOffset += diff;
1119 phdr->cbSsExtOffset += diff;
1120 phdr->cbFdOffset += diff;
1121 phdr->cbRfdOffset += diff;
1122 phdr->cbExtOffset += diff;
1123 }
1124 }
1125 #endif /* __sony_news && _SYSTYPE_SYSV */
1126
1127 #if __sgi
1128 /* Adjust the HDRR offsets in .mdebug and copy the
1129 line data if it's in its usual 'hole' in the object.
1130 Makes the new file debuggable with dbx.
1131 patches up two problems: the absolute file offsets
1132 in the HDRR record of .mdebug (see /usr/include/syms.h), and
1133 the ld bug that gets the line table in a hole in the
1134 elf file rather than in the .mdebug section proper.
1135 David Anderson. davea@sgi.com Jan 16,1994. */
1136 if (n == old_mdebug_index)
1137 {
1138 #define MDEBUGADJUST(__ct,__fileaddr) \
1139 if (n_phdrr->__ct > 0) \
1140 { \
1141 n_phdrr->__fileaddr += movement; \
1142 }
1143
1144 HDRR * o_phdrr = (HDRR *)((byte *)old_base + OLD_SECTION_H (n).sh_offset);
1145 HDRR * n_phdrr = (HDRR *)((byte *)new_base + NEW_SECTION_H (nn).sh_offset);
1146 unsigned movement = new_data2_size;
1147
1148 MDEBUGADJUST (idnMax, cbDnOffset);
1149 MDEBUGADJUST (ipdMax, cbPdOffset);
1150 MDEBUGADJUST (isymMax, cbSymOffset);
1151 MDEBUGADJUST (ioptMax, cbOptOffset);
1152 MDEBUGADJUST (iauxMax, cbAuxOffset);
1153 MDEBUGADJUST (issMax, cbSsOffset);
1154 MDEBUGADJUST (issExtMax, cbSsExtOffset);
1155 MDEBUGADJUST (ifdMax, cbFdOffset);
1156 MDEBUGADJUST (crfd, cbRfdOffset);
1157 MDEBUGADJUST (iextMax, cbExtOffset);
1158 /* The Line Section, being possible off in a hole of the object,
1159 requires special handling. */
1160 if (n_phdrr->cbLine > 0)
1161 {
1162 if (o_phdrr->cbLineOffset > (OLD_SECTION_H (n).sh_offset
1163 + OLD_SECTION_H (n).sh_size))
1164 {
1165 /* line data is in a hole in elf. do special copy and adjust
1166 for this ld mistake.
1167 */
1168 n_phdrr->cbLineOffset += movement;
1169
1170 memcpy (n_phdrr->cbLineOffset + new_base,
1171 o_phdrr->cbLineOffset + old_base, n_phdrr->cbLine);
1172 }
1173 else
1174 {
1175 /* somehow line data is in .mdebug as it is supposed to be. */
1176 MDEBUGADJUST (cbLine, cbLineOffset);
1177 }
1178 }
1179 }
1180 #endif /* __sgi */
1181
1182 /* If it is the symbol table, its st_shndx field needs to be patched. */
1183 if (NEW_SECTION_H (nn).sh_type == SHT_SYMTAB
1184 || NEW_SECTION_H (nn).sh_type == SHT_DYNSYM)
1185 {
1186 ElfW(Shdr) *spt = &NEW_SECTION_H (nn);
1187 unsigned int num = spt->sh_size / spt->sh_entsize;
1188 ElfW(Sym) * sym = (ElfW(Sym) *) (NEW_SECTION_H (nn).sh_offset +
1189 new_base);
1190 for (; num--; sym++)
1191 {
1192 if ((sym->st_shndx == SHN_UNDEF)
1193 || (sym->st_shndx == SHN_ABS)
1194 || (sym->st_shndx == SHN_COMMON))
1195 continue;
1196
1197 PATCH_INDEX (sym->st_shndx);
1198 }
1199 }
1200 }
1201
1202 /* Update the symbol values of _edata and _end. */
1203 for (n = new_file_h->e_shnum - 1; n; n--)
1204 {
1205 byte *symnames;
1206 ElfW(Sym) *symp, *symendp;
1207
1208 if (NEW_SECTION_H (n).sh_type != SHT_DYNSYM
1209 && NEW_SECTION_H (n).sh_type != SHT_SYMTAB)
1210 continue;
1211
1212 symnames = ((byte *) new_base
1213 + NEW_SECTION_H (NEW_SECTION_H (n).sh_link).sh_offset);
1214 symp = (ElfW(Sym) *) (NEW_SECTION_H (n).sh_offset + new_base);
1215 symendp = (ElfW(Sym) *) ((byte *)symp + NEW_SECTION_H (n).sh_size);
1216
1217 for (; symp < symendp; symp ++)
1218 if (strcmp ((char *) (symnames + symp->st_name), "_end") == 0
1219 || strcmp ((char *) (symnames + symp->st_name), "end") == 0
1220 || strcmp ((char *) (symnames + symp->st_name), "_edata") == 0
1221 || strcmp ((char *) (symnames + symp->st_name), "edata") == 0)
1222 memcpy (&symp->st_value, &new_bss_addr, sizeof (new_bss_addr));
1223 }
1224
1225 /* This loop seeks out relocation sections for the data section, so
1226 that it can undo relocations performed by the runtime linker. */
1227 #ifndef BROKEN_NOCOMBRELOC
1228 for (n = new_file_h->e_shnum - 1; n; n--)
1229 {
1230 ElfW(Shdr) section = NEW_SECTION_H (n);
1231
1232 /* Cause a compilation error if anyone uses n instead of nn below. */
1233 struct {int a;} n;
1234 (void)n.a; /* Prevent `unused variable' warnings. */
1235
1236 switch (section.sh_type)
1237 {
1238 default:
1239 break;
1240 case SHT_REL:
1241 case SHT_RELA:
1242 /* This code handles two different size structs, but there should
1243 be no harm in that provided that r_offset is always the first
1244 member. */
1245 nn = section.sh_info;
1246 if (!strcmp (old_section_names + NEW_SECTION_H (nn).sh_name, ".data")
1247 || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name),
1248 ".sdata")
1249 || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name),
1250 ".lit4")
1251 || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name),
1252 ".lit8")
1253 #ifdef IRIX6_5 /* see above */
1254 || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name),
1255 ".got")
1256 #endif
1257 || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name),
1258 ".sdata1")
1259 || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name),
1260 ".data1"))
1261 {
1262 ElfW(Addr) offset = (NEW_SECTION_H (nn).sh_addr
1263 - NEW_SECTION_H (nn).sh_offset);
1264 caddr_t reloc = old_base + section.sh_offset, end;
1265 for (end = reloc + section.sh_size; reloc < end;
1266 reloc += section.sh_entsize)
1267 {
1268 ElfW(Addr) addr = ((ElfW(Rel) *) reloc)->r_offset - offset;
1269 #ifdef __alpha__
1270 /* The Alpha ELF binutils currently have a bug that
1271 sometimes results in relocs that contain all
1272 zeroes. Work around this for now... */
1273 if (((ElfW(Rel) *) reloc)->r_offset == 0)
1274 continue;
1275 #endif
1276 memcpy (new_base + addr, old_base + addr, sizeof(ElfW(Addr)));
1277 }
1278 }
1279 break;
1280 }
1281 }
1282 #else /* BROKEN_NOCOMBRELOC */
1283 for (n = 1, n_unreloc_sections = 0; n < new_file_h->e_shnum; n++)
1284 if (!strcmp (old_section_names + NEW_SECTION_H (n).sh_name, ".data")
1285 || !strcmp (old_section_names + NEW_SECTION_H (n).sh_name, ".sdata")
1286 || !strcmp (old_section_names + NEW_SECTION_H (n).sh_name, ".lit4")
1287 || !strcmp (old_section_names + NEW_SECTION_H (n).sh_name, ".lit8")
1288 #ifdef IRIX6_5 /* see above */
1289 || !strcmp (old_section_names + NEW_SECTION_H (n).sh_name, ".got")
1290 #endif
1291 || !strcmp (old_section_names + NEW_SECTION_H (n).sh_name, ".sdata1")
1292 || !strcmp (old_section_names + NEW_SECTION_H (n).sh_name, ".data1"))
1293 {
1294 assert (n_unreloc_sections
1295 < (sizeof (unreloc_sections) / sizeof (unreloc_sections[0])));
1296 unreloc_sections[n_unreloc_sections++] = n;
1297 #ifdef DEBUG
1298 fprintf (stderr, "section %d: %s\n", n,
1299 old_section_names + NEW_SECTION_H (n).sh_name);
1300 #endif
1301 }
1302
1303 for (n = new_file_h->e_shnum - 1; n; n--)
1304 {
1305 ElfW(Shdr) section = NEW_SECTION_H (n);
1306 caddr_t reloc, end;
1307 ElfW(Addr) addr, offset;
1308 int target;
1309
1310 switch (section.sh_type)
1311 {
1312 default:
1313 break;
1314 case SHT_REL:
1315 case SHT_RELA:
1316 /* This code handles two different size structs, but there should
1317 be no harm in that provided that r_offset is always the first
1318 member. */
1319 for (reloc = old_base + section.sh_offset,
1320 end = reloc + section.sh_size;
1321 reloc < end;
1322 reloc += section.sh_entsize)
1323 {
1324 addr = ((ElfW(Rel) *) reloc)->r_offset;
1325 #ifdef __alpha__
1326 /* The Alpha ELF binutils currently have a bug that
1327 sometimes results in relocs that contain all
1328 zeroes. Work around this for now... */
1329 if (addr == 0)
1330 continue;
1331 #endif
1332 for (nn = 0; nn < n_unreloc_sections; nn++)
1333 {
1334 target = unreloc_sections[nn];
1335 if (NEW_SECTION_H (target).sh_addr <= addr
1336 && addr < (NEW_SECTION_H (target).sh_addr +
1337 NEW_SECTION_H (target).sh_size))
1338 {
1339 offset = (NEW_SECTION_H (target).sh_addr -
1340 NEW_SECTION_H (target).sh_offset);
1341 memcpy (new_base + addr - offset,
1342 old_base + addr - offset,
1343 sizeof (ElfW(Addr)));
1344 #ifdef DEBUG
1345 fprintf (stderr, "unrelocate: [%08lx] <= %08lx\n",
1346 (long) addr,
1347 (long) *((long *) (new_base + addr - offset)));
1348 #endif
1349 break;
1350 }
1351 }
1352 }
1353 break;
1354 }
1355 }
1356 #endif /* BROKEN_NOCOMBRELOC */
1357
1358 /* Write out new_file, and free the buffers. */
1359
1360 if (write (new_file, new_base, new_file_size) != new_file_size)
1361 #ifndef emacs
1362 fatal ("Didn't write %d bytes: errno %d\n",
1363 new_file_size, errno);
1364 #else
1365 fatal ("Didn't write %d bytes to %s: errno %d\n",
1366 new_file_size, new_base, errno);
1367 #endif
1368 munmap (old_base, old_file_size);
1369 munmap (new_base, new_file_size);
1370
1371 /* Close the files and make the new file executable. */
1372
1373 #if MAP_ANON == 0
1374 close (mmap_fd);
1375 #endif
1376
1377 if (close (old_file))
1378 fatal ("Can't close (%s): errno %d\n", old_name, errno);
1379
1380 if (close (new_file))
1381 fatal ("Can't close (%s): errno %d\n", new_name, errno);
1382
1383 if (stat (new_name, &stat_buf) == -1)
1384 fatal ("Can't stat (%s): errno %d\n", new_name, errno);
1385
1386 n = umask (777);
1387 umask (n);
1388 stat_buf.st_mode |= 0111 & ~n;
1389 if (chmod (new_name, stat_buf.st_mode) == -1)
1390 fatal ("Can't chmod (%s): errno %d\n", new_name, errno);
1391 }
1392
1393 /* arch-tag: e02e1512-95e2-4ef0-bba7-b6bce658f1e3
1394 (do not change this comment) */