Replace some inappropriate uses of toggle-read-only. (Bug#7292)
[emacs.git] / src / unexelf.c
bloba91af9458ebcc905973e17f3596b9f713e9513cf
1 /* Copyright (C) 1985, 1986, 1987, 1988, 1990, 1992, 1999, 2000, 2001,
2 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
3 Free Software Foundation, Inc.
5 This file is part of GNU Emacs.
7 GNU Emacs is free software: you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation, either version 3 of the License, or
10 (at your option) any later version.
12 GNU Emacs is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */
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! */
27 * unexec.c - Convert a running program into an a.out file.
29 * Author: Spencer W. Thomas
30 * Computer Science Dept.
31 * University of Utah
32 * Date: Tue Mar 2 1982
33 * Modified heavily since then.
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;
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.
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.
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.
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).
62 * The new file is set up to start at entry_address.
66 /* Even more heavily modified by james@bigtex.cactus.org of Dell Computer Co.
67 * ELF support added.
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.
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.
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.
84 * This is an example of how the section headers are changed. "Addr"
85 * is a process virtual address. "Offset" is a file offset.
87 raid:/nfs/raid/src/dist-18.56/src> dump -h temacs
89 temacs:
91 **** SECTION HEADER TABLE ****
92 [No] Type Flags Addr Offset Size Name
93 Link Info Adralgn Entsize
95 [1] 1 2 0x80480d4 0xd4 0x13 .interp
96 0 0 0x1 0
98 [2] 5 2 0x80480e8 0xe8 0x388 .hash
99 3 0 0x4 0x4
101 [3] 11 2 0x8048470 0x470 0x7f0 .dynsym
102 4 1 0x4 0x10
104 [4] 3 2 0x8048c60 0xc60 0x3ad .dynstr
105 0 0 0x1 0
107 [5] 9 2 0x8049010 0x1010 0x338 .rel.plt
108 3 7 0x4 0x8
110 [6] 1 6 0x8049348 0x1348 0x3 .init
111 0 0 0x4 0
113 [7] 1 6 0x804934c 0x134c 0x680 .plt
114 0 0 0x4 0x4
116 [8] 1 6 0x80499cc 0x19cc 0x3c56f .text
117 0 0 0x4 0
119 [9] 1 6 0x8085f3c 0x3df3c 0x3 .fini
120 0 0 0x4 0
122 [10] 1 2 0x8085f40 0x3df40 0x69c .rodata
123 0 0 0x4 0
125 [11] 1 2 0x80865dc 0x3e5dc 0xd51 .rodata1
126 0 0 0x4 0
128 [12] 1 3 0x8088330 0x3f330 0x20afc .data
129 0 0 0x4 0
131 [13] 1 3 0x80a8e2c 0x5fe2c 0x89d .data1
132 0 0 0x4 0
134 [14] 1 3 0x80a96cc 0x606cc 0x1a8 .got
135 0 0 0x4 0x4
137 [15] 6 3 0x80a9874 0x60874 0x80 .dynamic
138 4 0 0x4 0x8
140 [16] 8 3 0x80a98f4 0x608f4 0x449c .bss
141 0 0 0x4 0
143 [17] 2 0 0 0x608f4 0x9b90 .symtab
144 18 371 0x4 0x10
146 [18] 3 0 0 0x6a484 0x8526 .strtab
147 0 0 0x1 0
149 [19] 3 0 0 0x729aa 0x93 .shstrtab
150 0 0 0x1 0
152 [20] 1 0 0 0x72a3d 0x68b7 .comment
153 0 0 0x1 0
155 raid:/nfs/raid/src/dist-18.56/src> dump -h xemacs
157 xemacs:
159 **** SECTION HEADER TABLE ****
160 [No] Type Flags Addr Offset Size Name
161 Link Info Adralgn Entsize
163 [1] 1 2 0x80480d4 0xd4 0x13 .interp
164 0 0 0x1 0
166 [2] 5 2 0x80480e8 0xe8 0x388 .hash
167 3 0 0x4 0x4
169 [3] 11 2 0x8048470 0x470 0x7f0 .dynsym
170 4 1 0x4 0x10
172 [4] 3 2 0x8048c60 0xc60 0x3ad .dynstr
173 0 0 0x1 0
175 [5] 9 2 0x8049010 0x1010 0x338 .rel.plt
176 3 7 0x4 0x8
178 [6] 1 6 0x8049348 0x1348 0x3 .init
179 0 0 0x4 0
181 [7] 1 6 0x804934c 0x134c 0x680 .plt
182 0 0 0x4 0x4
184 [8] 1 6 0x80499cc 0x19cc 0x3c56f .text
185 0 0 0x4 0
187 [9] 1 6 0x8085f3c 0x3df3c 0x3 .fini
188 0 0 0x4 0
190 [10] 1 2 0x8085f40 0x3df40 0x69c .rodata
191 0 0 0x4 0
193 [11] 1 2 0x80865dc 0x3e5dc 0xd51 .rodata1
194 0 0 0x4 0
196 [12] 1 3 0x8088330 0x3f330 0x20afc .data
197 0 0 0x4 0
199 [13] 1 3 0x80a8e2c 0x5fe2c 0x89d .data1
200 0 0 0x4 0
202 [14] 1 3 0x80a96cc 0x606cc 0x1a8 .got
203 0 0 0x4 0x4
205 [15] 6 3 0x80a9874 0x60874 0x80 .dynamic
206 4 0 0x4 0x8
208 [16] 8 3 0x80c6800 0x7d800 0 .bss
209 0 0 0x4 0
211 [17] 2 0 0 0x7d800 0x9b90 .symtab
212 18 371 0x4 0x10
214 [18] 3 0 0 0x87390 0x8526 .strtab
215 0 0 0x1 0
217 [19] 3 0 0 0x8f8b6 0x93 .shstrtab
218 0 0 0x1 0
220 [20] 1 0 0 0x8f949 0x68b7 .comment
221 0 0 0x1 0
223 [21] 1 3 0x80a98f4 0x608f4 0x1cf0c .data
224 0 0 0x4 0
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.
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.
235 raid:/nfs/raid/src/dist-18.56/src> dump -f temacs
237 temacs:
239 **** ELF HEADER ****
240 Class Data Type Machine Version
241 Entry Phoff Shoff Flags Ehsize
242 Phentsize Phnum Shentsz Shnum Shstrndx
244 1 1 2 3 1
245 0x80499cc 0x34 0x792f4 0 0x34
246 0x20 5 0x28 21 19
248 raid:/nfs/raid/src/dist-18.56/src> dump -f xemacs
250 xemacs:
252 **** ELF HEADER ****
253 Class Data Type Machine Version
254 Entry Phoff Shoff Flags Ehsize
255 Phentsize Phnum Shentsz Shnum Shstrndx
257 1 1 2 3 1
258 0x80499cc 0x34 0x96200 0 0x34
259 0x20 5 0x28 22 19
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
267 raid:/nfs/raid/src/dist-18.56/src> dump -o temacs
269 temacs:
270 ***** PROGRAM EXECUTION HEADER *****
271 Type Offset Vaddr Paddr
272 Filesz Memsz Flags Align
274 6 0x34 0x8048034 0
275 0xa0 0xa0 5 0
277 3 0xd4 0 0
278 0x13 0 4 0
280 1 0x34 0x8048034 0
281 0x3f2f9 0x3f2f9 5 0x1000
283 1 0x3f330 0x8088330 0
284 0x215c4 0x25a60 7 0x1000
286 2 0x60874 0x80a9874 0
287 0x80 0 7 0
289 raid:/nfs/raid/src/dist-18.56/src> dump -o xemacs
291 xemacs:
292 ***** PROGRAM EXECUTION HEADER *****
293 Type Offset Vaddr Paddr
294 Filesz Memsz Flags Align
296 6 0x34 0x8048034 0
297 0xa0 0xa0 5 0
299 3 0xd4 0 0
300 0x13 0 4 0
302 1 0x34 0x8048034 0
303 0x3f2f9 0x3f2f9 5 0x1000
305 1 0x3f330 0x8088330 0
306 0x3e4d0 0x3e4d0 7 0x1000
308 2 0x60874 0x80a9874 0
309 0x80 0 7 0
314 /* Modified by wtien@urbana.mcd.mot.com of Motorola Inc.
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.
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:
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.
336 * The above example now should look like:
338 **** SECTION HEADER TABLE ****
339 [No] Type Flags Addr Offset Size Name
340 Link Info Adralgn Entsize
342 [1] 1 2 0x80480d4 0xd4 0x13 .interp
343 0 0 0x1 0
345 [2] 5 2 0x80480e8 0xe8 0x388 .hash
346 3 0 0x4 0x4
348 [3] 11 2 0x8048470 0x470 0x7f0 .dynsym
349 4 1 0x4 0x10
351 [4] 3 2 0x8048c60 0xc60 0x3ad .dynstr
352 0 0 0x1 0
354 [5] 9 2 0x8049010 0x1010 0x338 .rel.plt
355 3 7 0x4 0x8
357 [6] 1 6 0x8049348 0x1348 0x3 .init
358 0 0 0x4 0
360 [7] 1 6 0x804934c 0x134c 0x680 .plt
361 0 0 0x4 0x4
363 [8] 1 6 0x80499cc 0x19cc 0x3c56f .text
364 0 0 0x4 0
366 [9] 1 6 0x8085f3c 0x3df3c 0x3 .fini
367 0 0 0x4 0
369 [10] 1 2 0x8085f40 0x3df40 0x69c .rodata
370 0 0 0x4 0
372 [11] 1 2 0x80865dc 0x3e5dc 0xd51 .rodata1
373 0 0 0x4 0
375 [12] 1 3 0x8088330 0x3f330 0x20afc .data
376 0 0 0x4 0
378 [13] 1 3 0x80a8e2c 0x5fe2c 0x89d .data1
379 0 0 0x4 0
381 [14] 1 3 0x80a96cc 0x606cc 0x1a8 .got
382 0 0 0x4 0x4
384 [15] 6 3 0x80a9874 0x60874 0x80 .dynamic
385 4 0 0x4 0x8
387 [16] 1 3 0x80a98f4 0x608f4 0x1cf0c .data
388 0 0 0x4 0
390 [17] 8 3 0x80c6800 0x7d800 0 .bss
391 0 0 0x4 0
393 [18] 2 0 0 0x7d800 0x9b90 .symtab
394 19 371 0x4 0x10
396 [19] 3 0 0 0x87390 0x8526 .strtab
397 0 0 0x1 0
399 [20] 3 0 0 0x8f8b6 0x93 .shstrtab
400 0 0 0x1 0
402 [21] 1 0 0 0x8f949 0x68b7 .comment
403 0 0 0x1 0
407 /* We do not use mmap because that fails with NFS.
408 Instead we read the whole file, modify it, and write it out. */
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
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 (_SYSTYPE_SYSV)
430 #include <sys/elf_mips.h>
431 #include <sym.h>
432 #endif /* _SYSTYPE_SYSV */
433 #if __sgi
434 #include <syms.h> /* for HDRR declaration */
435 #endif /* __sgi */
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
445 #ifndef MAP_FAILED
446 #define MAP_FAILED ((void *) -1)
447 #endif
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
484 #ifdef __NetBSD__
486 * NetBSD does not have normal-looking user-land ELF support.
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>
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
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 */
512 # ifdef __alpha__
513 # include <sys/exec_ecoff.h>
514 # define HDRR struct ecoff_symhdr
515 # define pHDRR HDRR *
516 # endif /* __alpha__ */
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__ */
524 #ifdef __OpenBSD__
525 # include <sys/exec_elf.h>
526 #endif
528 #if __GNU_LIBRARY__ - 0 >= 6
529 # include <link.h> /* get ElfW etc */
530 #endif
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
548 #ifndef ELF_BSS_SECTION_NAME
549 #define ELF_BSS_SECTION_NAME ".bss"
550 #endif
552 /* Get the address of a particular section or program header entry,
553 * accounting for the size of the entries.
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)
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
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)))
588 #define PATCH_INDEX(n) \
589 do { \
590 if ((int) (n) >= old_bss_index) \
591 (n)++; } while (0)
592 typedef unsigned char byte;
594 /* Round X up to a multiple of Y. */
596 static ElfW(Addr)
597 round_up (x, y)
598 ElfW(Addr) x, y;
600 int rem = x % y;
601 if (rem == 0)
602 return x;
603 return x - rem + y;
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.
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. */
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;
622 int idx;
624 for (idx = 1; idx < old_file_h->e_shnum; idx++)
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;
634 if (idx == old_file_h->e_shnum)
636 if (noerror)
637 return -1;
638 else
639 fatal ("Can't find %s in %s.\n", name, file_name);
642 return idx;
645 /* ****************************************************************
646 * unexec
648 * driving logic.
650 * In ELF, this works by replacing the old .bss section with a new
651 * .data section, and inserting an empty .bss immediately afterwards.
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;
659 int new_file, old_file, new_file_size;
661 /* Pointers to the base of the image of the two files. */
662 caddr_t old_base, new_base;
664 #if MAP_ANON == 0
665 int mmap_fd;
666 #else
667 # define mmap_fd -1
668 #endif
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;
676 /* Point to the section name table in the old file. */
677 char *old_section_names;
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 ElfW(Off) old_bss_offset;
684 ElfW(Word) new_data2_incr;
686 int n, nn;
687 int old_bss_index, old_sbss_index, old_plt_index;
688 int old_data_index, new_data2_index;
689 int old_mdebug_index;
690 struct stat stat_buf;
691 int old_file_size;
693 /* Open the old file, allocate a buffer of the right size, and read
694 in the file contents. */
696 old_file = open (old_name, O_RDONLY);
698 if (old_file < 0)
699 fatal ("Can't open %s for reading: errno %d\n", old_name, errno);
701 if (fstat (old_file, &stat_buf) == -1)
702 fatal ("Can't fstat (%s): errno %d\n", old_name, errno);
704 #if MAP_ANON == 0
705 mmap_fd = open ("/dev/zero", O_RDONLY);
706 if (mmap_fd < 0)
707 fatal ("Can't open /dev/zero for reading: errno %d\n", errno, 0);
708 #endif
710 /* We cannot use malloc here because that may use sbrk. If it does,
711 we'd dump our temporary buffers with Emacs, and we'd have to be
712 extra careful to use the correct value of sbrk(0) after
713 allocating all buffers in the code below, which we aren't. */
714 old_file_size = stat_buf.st_size;
715 old_base = mmap (NULL, old_file_size, PROT_READ | PROT_WRITE,
716 MAP_ANON | MAP_PRIVATE, mmap_fd, 0);
717 if (old_base == MAP_FAILED)
718 fatal ("Can't allocate buffer for %s\n", old_name, 0);
720 if (read (old_file, old_base, stat_buf.st_size) != stat_buf.st_size)
721 fatal ("Didn't read all of %s: errno %d\n", old_name, errno);
723 /* Get pointers to headers & section names */
725 old_file_h = (ElfW(Ehdr) *) old_base;
726 old_program_h = (ElfW(Phdr) *) ((byte *) old_base + old_file_h->e_phoff);
727 old_section_h = (ElfW(Shdr) *) ((byte *) old_base + old_file_h->e_shoff);
728 old_section_names = (char *) old_base
729 + OLD_SECTION_H (old_file_h->e_shstrndx).sh_offset;
731 /* Find the mdebug section, if any. */
733 old_mdebug_index = find_section (".mdebug", old_section_names,
734 old_name, old_file_h, old_section_h, 1);
736 /* Find the old .bss section. Figure out parameters of the new
737 data2 and bss sections. */
739 old_bss_index = find_section (".bss", old_section_names,
740 old_name, old_file_h, old_section_h, 0);
742 old_sbss_index = find_section (".sbss", old_section_names,
743 old_name, old_file_h, old_section_h, 1);
744 if (old_sbss_index != -1)
745 if (OLD_SECTION_H (old_sbss_index).sh_type != SHT_NOBITS)
746 old_sbss_index = -1;
748 /* PowerPC64 has .plt in the BSS section. */
749 old_plt_index = find_section (".plt", old_section_names,
750 old_name, old_file_h, old_section_h, 1);
751 if (old_plt_index != -1)
752 if (OLD_SECTION_H (old_plt_index).sh_type != SHT_NOBITS)
753 old_plt_index = -1;
755 if (old_sbss_index == -1 && old_plt_index == -1)
757 old_bss_addr = OLD_SECTION_H (old_bss_index).sh_addr;
758 old_bss_size = OLD_SECTION_H (old_bss_index).sh_size;
759 old_bss_offset = OLD_SECTION_H (old_bss_index).sh_offset;
760 new_data2_index = old_bss_index;
762 else if (old_plt_index != -1
763 && (old_sbss_index == -1
764 || (OLD_SECTION_H (old_sbss_index).sh_addr
765 > OLD_SECTION_H (old_plt_index).sh_addr)))
767 old_bss_addr = OLD_SECTION_H (old_plt_index).sh_addr;
768 old_bss_size = OLD_SECTION_H (old_bss_index).sh_size
769 + OLD_SECTION_H (old_plt_index).sh_size;
770 if (old_sbss_index != -1)
771 old_bss_size += OLD_SECTION_H (old_sbss_index).sh_size;
772 old_bss_offset = OLD_SECTION_H (old_plt_index).sh_offset;
773 new_data2_index = old_plt_index;
775 else
777 old_bss_addr = OLD_SECTION_H (old_sbss_index).sh_addr;
778 old_bss_size = OLD_SECTION_H (old_bss_index).sh_size
779 + OLD_SECTION_H (old_sbss_index).sh_size;
780 old_bss_offset = OLD_SECTION_H (old_sbss_index).sh_offset;
781 new_data2_index = old_sbss_index;
784 /* Find the old .data section. Figure out parameters of
785 the new data2 and bss sections. */
787 old_data_index = find_section (".data", old_section_names,
788 old_name, old_file_h, old_section_h, 0);
790 #if defined (emacs) || !defined (DEBUG)
791 new_bss_addr = (ElfW(Addr)) sbrk (0);
792 #else
793 new_bss_addr = old_bss_addr + old_bss_size + 0x1234;
794 #endif
795 new_data2_addr = old_bss_addr;
796 new_data2_size = new_bss_addr - old_bss_addr;
797 new_data2_offset = OLD_SECTION_H (old_data_index).sh_offset
798 + (new_data2_addr - OLD_SECTION_H (old_data_index).sh_addr);
799 /* This is the amount by which the sections following the bss sections
800 must be shifted in the image. It can differ from new_data2_size if
801 the end of the old .data section (and thus the offset of the .bss
802 section) was unaligned. */
803 new_data2_incr = new_data2_size + (new_data2_offset - old_bss_offset);
805 #ifdef DEBUG
806 fprintf (stderr, "old_bss_index %d\n", old_bss_index);
807 fprintf (stderr, "old_bss_addr %x\n", old_bss_addr);
808 fprintf (stderr, "old_bss_size %x\n", old_bss_size);
809 fprintf (stderr, "old_bss_offset %x\n", old_bss_offset);
810 fprintf (stderr, "new_bss_addr %x\n", new_bss_addr);
811 fprintf (stderr, "new_data2_addr %x\n", new_data2_addr);
812 fprintf (stderr, "new_data2_size %x\n", new_data2_size);
813 fprintf (stderr, "new_data2_offset %x\n", new_data2_offset);
814 fprintf (stderr, "new_data2_incr %x\n", new_data2_incr);
815 #endif
817 if ((unsigned) new_bss_addr < (unsigned) old_bss_addr + old_bss_size)
818 fatal (".bss shrank when undumping???\n", 0, 0);
820 /* Set the output file to the right size. Allocate a buffer to hold
821 the image of the new file. Set pointers to various interesting
822 objects. stat_buf still has old_file data. */
824 new_file = open (new_name, O_RDWR | O_CREAT, 0666);
825 if (new_file < 0)
826 fatal ("Can't creat (%s): errno %d\n", new_name, errno);
828 new_file_size = stat_buf.st_size + old_file_h->e_shentsize + new_data2_incr;
830 if (ftruncate (new_file, new_file_size))
831 fatal ("Can't ftruncate (%s): errno %d\n", new_name, errno);
833 new_base = mmap (NULL, new_file_size, PROT_READ | PROT_WRITE,
834 MAP_ANON | MAP_PRIVATE, mmap_fd, 0);
835 if (new_base == MAP_FAILED)
836 fatal ("Can't allocate buffer for %s\n", old_name, 0);
838 new_file_h = (ElfW(Ehdr) *) new_base;
839 new_program_h = (ElfW(Phdr) *) ((byte *) new_base + old_file_h->e_phoff);
840 new_section_h = (ElfW(Shdr) *)
841 ((byte *) new_base + old_file_h->e_shoff + new_data2_incr);
843 /* Make our new file, program and section headers as copies of the
844 originals. */
846 memcpy (new_file_h, old_file_h, old_file_h->e_ehsize);
847 memcpy (new_program_h, old_program_h,
848 old_file_h->e_phnum * old_file_h->e_phentsize);
850 /* Modify the e_shstrndx if necessary. */
851 PATCH_INDEX (new_file_h->e_shstrndx);
853 /* Fix up file header. We'll add one section. Section header is
854 further away now. */
856 new_file_h->e_shoff += new_data2_incr;
857 new_file_h->e_shnum += 1;
859 #ifdef DEBUG
860 fprintf (stderr, "Old section offset %x\n", old_file_h->e_shoff);
861 fprintf (stderr, "Old section count %d\n", old_file_h->e_shnum);
862 fprintf (stderr, "New section offset %x\n", new_file_h->e_shoff);
863 fprintf (stderr, "New section count %d\n", new_file_h->e_shnum);
864 #endif
866 /* Fix up a new program header. Extend the writable data segment so
867 that the bss area is covered too. Find that segment by looking
868 for a segment that ends just before the .bss area. Make sure
869 that no segments are above the new .data2. Put a loop at the end
870 to adjust the offset and address of any segment that is above
871 data2, just in case we decide to allow this later. */
873 for (n = new_file_h->e_phnum - 1; n >= 0; n--)
875 /* Compute maximum of all requirements for alignment of section. */
876 ElfW(Word) alignment = (NEW_PROGRAM_H (n)).p_align;
877 if ((OLD_SECTION_H (old_bss_index)).sh_addralign > alignment)
878 alignment = OLD_SECTION_H (old_bss_index).sh_addralign;
880 #ifdef __sgi
881 /* According to r02kar@x4u2.desy.de (Karsten Kuenne)
882 and oliva@gnu.org (Alexandre Oliva), on IRIX 5.2, we
883 always get "Program segment above .bss" when dumping
884 when the executable doesn't have an sbss section. */
885 if (old_sbss_index != -1)
886 #endif /* __sgi */
887 if (NEW_PROGRAM_H (n).p_vaddr + NEW_PROGRAM_H (n).p_filesz
888 > (old_sbss_index == -1
889 ? old_bss_addr
890 : round_up (old_bss_addr, alignment)))
891 fatal ("Program segment above .bss in %s\n", old_name, 0);
893 if (NEW_PROGRAM_H (n).p_type == PT_LOAD
894 && (round_up ((NEW_PROGRAM_H (n)).p_vaddr
895 + (NEW_PROGRAM_H (n)).p_filesz,
896 alignment)
897 == round_up (old_bss_addr, alignment)))
898 break;
900 if (n < 0)
901 fatal ("Couldn't find segment next to .bss in %s\n", old_name, 0);
903 /* Make sure that the size includes any padding before the old .bss
904 section. */
905 NEW_PROGRAM_H (n).p_filesz = new_bss_addr - NEW_PROGRAM_H (n).p_vaddr;
906 NEW_PROGRAM_H (n).p_memsz = NEW_PROGRAM_H (n).p_filesz;
908 #if 0 /* Maybe allow section after data2 - does this ever happen? */
909 for (n = new_file_h->e_phnum - 1; n >= 0; n--)
911 if (NEW_PROGRAM_H (n).p_vaddr
912 && NEW_PROGRAM_H (n).p_vaddr >= new_data2_addr)
913 NEW_PROGRAM_H (n).p_vaddr += new_data2_size - old_bss_size;
915 if (NEW_PROGRAM_H (n).p_offset >= new_data2_offset)
916 NEW_PROGRAM_H (n).p_offset += new_data2_incr;
918 #endif
920 /* Fix up section headers based on new .data2 section. Any section
921 whose offset or virtual address is after the new .data2 section
922 gets its value adjusted. .bss size becomes zero and new address
923 is set. data2 section header gets added by copying the existing
924 .data header and modifying the offset, address and size. */
926 /* Walk through all section headers, insert the new data2 section right
927 before the new bss section. */
928 for (n = 1, nn = 1; n < (int) old_file_h->e_shnum; n++, nn++)
930 caddr_t src;
931 /* If it is (s)bss section, insert the new data2 section before it. */
932 /* new_data2_index is the index of either old_sbss or old_bss, that was
933 chosen as a section for new_data2. */
934 if (n == new_data2_index)
936 /* Steal the data section header for this data2 section. */
937 memcpy (&NEW_SECTION_H (nn), &OLD_SECTION_H (old_data_index),
938 new_file_h->e_shentsize);
940 NEW_SECTION_H (nn).sh_addr = new_data2_addr;
941 NEW_SECTION_H (nn).sh_offset = new_data2_offset;
942 NEW_SECTION_H (nn).sh_size = new_data2_size;
943 /* Use the bss section's alignment. This will assure that the
944 new data2 section always be placed in the same spot as the old
945 bss section by any other application. */
946 NEW_SECTION_H (nn).sh_addralign = OLD_SECTION_H (n).sh_addralign;
948 /* Now copy over what we have in the memory now. */
949 memcpy (NEW_SECTION_H (nn).sh_offset + new_base,
950 (caddr_t) OLD_SECTION_H (n).sh_addr,
951 new_data2_size);
952 nn++;
955 memcpy (&NEW_SECTION_H (nn), &OLD_SECTION_H (n),
956 old_file_h->e_shentsize);
958 if (n == old_bss_index
959 /* The new bss and sbss section's size is zero, and its file offset
960 and virtual address should be off by NEW_DATA2_SIZE. */
961 || n == old_sbss_index || n == old_plt_index
964 /* NN should be `old_s?bss_index + 1' at this point. */
965 NEW_SECTION_H (nn).sh_offset = new_data2_offset + new_data2_size;
966 NEW_SECTION_H (nn).sh_addr = new_data2_addr + new_data2_size;
967 /* Let the new bss section address alignment be the same as the
968 section address alignment followed the old bss section, so
969 this section will be placed in exactly the same place. */
970 NEW_SECTION_H (nn).sh_addralign = OLD_SECTION_H (nn).sh_addralign;
971 NEW_SECTION_H (nn).sh_size = 0;
973 else
975 /* Any section that was originally placed after the .bss
976 section should now be off by NEW_DATA2_INCR. If a
977 section overlaps the .bss section, consider it to be
978 placed after the .bss section. Overlap can occur if the
979 section just before .bss has less-strict alignment; this
980 was observed between .symtab and .bss on Solaris 2.5.1
981 (sparc) with GCC snapshot 960602.
983 > dump -h temacs
985 temacs:
987 **** SECTION HEADER TABLE ****
988 [No] Type Flags Addr Offset Size Name
989 Link Info Adralgn Entsize
991 [22] 1 3 0x335150 0x315150 0x4 .data.rel.local
992 0 0 0x4 0
994 [23] 8 3 0x335158 0x315158 0x42720 .bss
995 0 0 0x8 0
997 [24] 2 0 0 0x315154 0x1c9d0 .symtab
998 25 1709 0x4 0x10
1001 if (NEW_SECTION_H (nn).sh_offset >= old_bss_offset
1002 || (NEW_SECTION_H (nn).sh_offset + NEW_SECTION_H (nn).sh_size
1003 > new_data2_offset))
1004 NEW_SECTION_H (nn).sh_offset += new_data2_incr;
1006 /* Any section that was originally placed after the section
1007 header table should now be off by the size of one section
1008 header table entry. */
1009 if (NEW_SECTION_H (nn).sh_offset > new_file_h->e_shoff)
1010 NEW_SECTION_H (nn).sh_offset += new_file_h->e_shentsize;
1013 /* If any section hdr refers to the section after the new .data
1014 section, make it refer to next one because we have inserted
1015 a new section in between. */
1017 PATCH_INDEX (NEW_SECTION_H (nn).sh_link);
1018 /* For symbol tables, info is a symbol table index,
1019 so don't change it. */
1020 if (NEW_SECTION_H (nn).sh_type != SHT_SYMTAB
1021 && NEW_SECTION_H (nn).sh_type != SHT_DYNSYM)
1022 PATCH_INDEX (NEW_SECTION_H (nn).sh_info);
1024 if (old_sbss_index != -1)
1025 if (!strcmp (old_section_names + NEW_SECTION_H (nn).sh_name, ".sbss"))
1027 NEW_SECTION_H (nn).sh_offset =
1028 round_up (NEW_SECTION_H (nn).sh_offset,
1029 NEW_SECTION_H (nn).sh_addralign);
1030 NEW_SECTION_H (nn).sh_type = SHT_PROGBITS;
1033 /* Now, start to copy the content of sections. */
1034 if (NEW_SECTION_H (nn).sh_type == SHT_NULL
1035 || NEW_SECTION_H (nn).sh_type == SHT_NOBITS)
1036 continue;
1038 /* Write out the sections. .data and .data1 (and data2, called
1039 ".data" in the strings table) get copied from the current process
1040 instead of the old file. */
1041 if (!strcmp (old_section_names + NEW_SECTION_H (n).sh_name, ".data")
1042 || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name),
1043 ".sdata")
1044 || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name),
1045 ".lit4")
1046 || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name),
1047 ".lit8")
1048 /* The conditional bit below was in Oliva's original code
1049 (1999-08-25) and seems to have been dropped by mistake
1050 subsequently. It prevents a crash at startup under X in
1051 `IRIX64 6.5 6.5.17m', whether compiled on that relase or
1052 an earlier one. It causes no trouble on the other ELF
1053 platforms I could test (Irix 6.5.15m, Solaris 8, Debian
1054 Potato x86, Debian Woody SPARC); however, it's reported
1055 to cause crashes under some version of GNU/Linux. It's
1056 not yet clear what's changed in that Irix version to
1057 cause the problem, or why the fix sometimes fails under
1058 GNU/Linux. There's probably no good reason to have
1059 something Irix-specific here, but this will have to do
1060 for now. IRIX6_5 is the most specific macro we have to
1061 test. -- fx 2002-10-01
1063 The issue _looks_ as though it's gone away on 6.5.18m,
1064 but maybe it's still lurking, to be triggered by some
1065 change in the binary. It appears to concern the dynamic
1066 loader, but I never got anywhere with an SGI support call
1067 seeking clues. -- fx 2002-11-29. */
1068 #ifdef IRIX6_5
1069 || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name),
1070 ".got")
1071 #endif
1072 || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name),
1073 ".sdata1")
1074 || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name),
1075 ".data1")
1076 || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name),
1077 ".sbss"))
1078 src = (caddr_t) OLD_SECTION_H (n).sh_addr;
1079 else
1080 src = old_base + OLD_SECTION_H (n).sh_offset;
1082 memcpy (NEW_SECTION_H (nn).sh_offset + new_base, src,
1083 NEW_SECTION_H (nn).sh_size);
1085 #ifdef __alpha__
1086 /* Update Alpha COFF symbol table: */
1087 if (strcmp (old_section_names + OLD_SECTION_H (n).sh_name, ".mdebug")
1088 == 0)
1090 pHDRR symhdr = (pHDRR) (NEW_SECTION_H (nn).sh_offset + new_base);
1092 symhdr->cbLineOffset += new_data2_size;
1093 symhdr->cbDnOffset += new_data2_size;
1094 symhdr->cbPdOffset += new_data2_size;
1095 symhdr->cbSymOffset += new_data2_size;
1096 symhdr->cbOptOffset += new_data2_size;
1097 symhdr->cbAuxOffset += new_data2_size;
1098 symhdr->cbSsOffset += new_data2_size;
1099 symhdr->cbSsExtOffset += new_data2_size;
1100 symhdr->cbFdOffset += new_data2_size;
1101 symhdr->cbRfdOffset += new_data2_size;
1102 symhdr->cbExtOffset += new_data2_size;
1104 #endif /* __alpha__ */
1106 #if defined (_SYSTYPE_SYSV)
1107 if (NEW_SECTION_H (nn).sh_type == SHT_MIPS_DEBUG
1108 && old_mdebug_index != -1)
1110 int diff = NEW_SECTION_H(nn).sh_offset
1111 - OLD_SECTION_H(old_mdebug_index).sh_offset;
1112 HDRR *phdr = (HDRR *)(NEW_SECTION_H (nn).sh_offset + new_base);
1114 if (diff)
1116 phdr->cbLineOffset += diff;
1117 phdr->cbDnOffset += diff;
1118 phdr->cbPdOffset += diff;
1119 phdr->cbSymOffset += diff;
1120 phdr->cbOptOffset += diff;
1121 phdr->cbAuxOffset += diff;
1122 phdr->cbSsOffset += diff;
1123 phdr->cbSsExtOffset += diff;
1124 phdr->cbFdOffset += diff;
1125 phdr->cbRfdOffset += diff;
1126 phdr->cbExtOffset += diff;
1129 #endif /* _SYSTYPE_SYSV */
1131 #if __sgi
1132 /* Adjust the HDRR offsets in .mdebug and copy the
1133 line data if it's in its usual 'hole' in the object.
1134 Makes the new file debuggable with dbx.
1135 patches up two problems: the absolute file offsets
1136 in the HDRR record of .mdebug (see /usr/include/syms.h), and
1137 the ld bug that gets the line table in a hole in the
1138 elf file rather than in the .mdebug section proper.
1139 David Anderson. davea@sgi.com Jan 16,1994. */
1140 if (n == old_mdebug_index)
1142 #define MDEBUGADJUST(__ct,__fileaddr) \
1143 if (n_phdrr->__ct > 0) \
1145 n_phdrr->__fileaddr += movement; \
1148 HDRR * o_phdrr = (HDRR *)((byte *)old_base + OLD_SECTION_H (n).sh_offset);
1149 HDRR * n_phdrr = (HDRR *)((byte *)new_base + NEW_SECTION_H (nn).sh_offset);
1150 unsigned movement = new_data2_size;
1152 MDEBUGADJUST (idnMax, cbDnOffset);
1153 MDEBUGADJUST (ipdMax, cbPdOffset);
1154 MDEBUGADJUST (isymMax, cbSymOffset);
1155 MDEBUGADJUST (ioptMax, cbOptOffset);
1156 MDEBUGADJUST (iauxMax, cbAuxOffset);
1157 MDEBUGADJUST (issMax, cbSsOffset);
1158 MDEBUGADJUST (issExtMax, cbSsExtOffset);
1159 MDEBUGADJUST (ifdMax, cbFdOffset);
1160 MDEBUGADJUST (crfd, cbRfdOffset);
1161 MDEBUGADJUST (iextMax, cbExtOffset);
1162 /* The Line Section, being possible off in a hole of the object,
1163 requires special handling. */
1164 if (n_phdrr->cbLine > 0)
1166 if (o_phdrr->cbLineOffset > (OLD_SECTION_H (n).sh_offset
1167 + OLD_SECTION_H (n).sh_size))
1169 /* line data is in a hole in elf. do special copy and adjust
1170 for this ld mistake.
1172 n_phdrr->cbLineOffset += movement;
1174 memcpy (n_phdrr->cbLineOffset + new_base,
1175 o_phdrr->cbLineOffset + old_base, n_phdrr->cbLine);
1177 else
1179 /* somehow line data is in .mdebug as it is supposed to be. */
1180 MDEBUGADJUST (cbLine, cbLineOffset);
1184 #endif /* __sgi */
1186 /* If it is the symbol table, its st_shndx field needs to be patched. */
1187 if (NEW_SECTION_H (nn).sh_type == SHT_SYMTAB
1188 || NEW_SECTION_H (nn).sh_type == SHT_DYNSYM)
1190 ElfW(Shdr) *spt = &NEW_SECTION_H (nn);
1191 unsigned int num = spt->sh_size / spt->sh_entsize;
1192 ElfW(Sym) * sym = (ElfW(Sym) *) (NEW_SECTION_H (nn).sh_offset +
1193 new_base);
1194 for (; num--; sym++)
1196 if ((sym->st_shndx == SHN_UNDEF)
1197 || (sym->st_shndx == SHN_ABS)
1198 || (sym->st_shndx == SHN_COMMON))
1199 continue;
1201 PATCH_INDEX (sym->st_shndx);
1206 /* Update the symbol values of _edata and _end. */
1207 for (n = new_file_h->e_shnum - 1; n; n--)
1209 byte *symnames;
1210 ElfW(Sym) *symp, *symendp;
1212 if (NEW_SECTION_H (n).sh_type != SHT_DYNSYM
1213 && NEW_SECTION_H (n).sh_type != SHT_SYMTAB)
1214 continue;
1216 symnames = ((byte *) new_base
1217 + NEW_SECTION_H (NEW_SECTION_H (n).sh_link).sh_offset);
1218 symp = (ElfW(Sym) *) (NEW_SECTION_H (n).sh_offset + new_base);
1219 symendp = (ElfW(Sym) *) ((byte *)symp + NEW_SECTION_H (n).sh_size);
1221 for (; symp < symendp; symp ++)
1223 if (strcmp ((char *) (symnames + symp->st_name), "_end") == 0
1224 || strcmp ((char *) (symnames + symp->st_name), "end") == 0
1225 || strcmp ((char *) (symnames + symp->st_name), "_edata") == 0
1226 || strcmp ((char *) (symnames + symp->st_name), "edata") == 0)
1227 memcpy (&symp->st_value, &new_bss_addr, sizeof (new_bss_addr));
1229 /* Strictly speaking, #ifdef below is not necessary. But we
1230 keep it to indicate that this kind of change may also be
1231 necessary for other unexecs to support GNUstep. */
1232 #ifdef NS_IMPL_GNUSTEP
1233 /* ObjC runtime modifies the values of some data structures
1234 such as classes and selectors in the .data section after
1235 loading. As the dump process copies the .data section
1236 from the current process, that causes problems when the
1237 modified classes are reinitialized in the dumped
1238 executable. We copy such data from the old file, not
1239 from the current process. */
1240 if (strncmp ((char *) (symnames + symp->st_name),
1241 "_OBJC_", sizeof ("_OBJC_") - 1) == 0)
1243 caddr_t old, new;
1245 new = ((symp->st_value - NEW_SECTION_H (symp->st_shndx).sh_addr)
1246 + NEW_SECTION_H (symp->st_shndx).sh_offset + new_base);
1247 /* "Unpatch" index. */
1248 nn = symp->st_shndx;
1249 if (nn > old_bss_index)
1250 nn--;
1251 old = ((symp->st_value - NEW_SECTION_H (symp->st_shndx).sh_addr)
1252 + OLD_SECTION_H (nn).sh_offset + old_base);
1253 memcpy (new, old, symp->st_size);
1255 #endif
1259 /* This loop seeks out relocation sections for the data section, so
1260 that it can undo relocations performed by the runtime linker. */
1261 for (n = new_file_h->e_shnum - 1; n; n--)
1263 ElfW(Shdr) section = NEW_SECTION_H (n);
1265 /* Cause a compilation error if anyone uses n instead of nn below. */
1266 struct {int a;} n;
1267 (void)n.a; /* Prevent `unused variable' warnings. */
1269 switch (section.sh_type)
1271 default:
1272 break;
1273 case SHT_REL:
1274 case SHT_RELA:
1275 /* This code handles two different size structs, but there should
1276 be no harm in that provided that r_offset is always the first
1277 member. */
1278 nn = section.sh_info;
1279 if (!strcmp (old_section_names + NEW_SECTION_H (nn).sh_name, ".data")
1280 || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name),
1281 ".sdata")
1282 || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name),
1283 ".lit4")
1284 || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name),
1285 ".lit8")
1286 #ifdef IRIX6_5 /* see above */
1287 || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name),
1288 ".got")
1289 #endif
1290 || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name),
1291 ".sdata1")
1292 || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name),
1293 ".data1"))
1295 ElfW(Addr) offset = (NEW_SECTION_H (nn).sh_addr
1296 - NEW_SECTION_H (nn).sh_offset);
1297 caddr_t reloc = old_base + section.sh_offset, end;
1298 for (end = reloc + section.sh_size; reloc < end;
1299 reloc += section.sh_entsize)
1301 ElfW(Addr) addr = ((ElfW(Rel) *) reloc)->r_offset - offset;
1302 #ifdef __alpha__
1303 /* The Alpha ELF binutils currently have a bug that
1304 sometimes results in relocs that contain all
1305 zeroes. Work around this for now... */
1306 if (((ElfW(Rel) *) reloc)->r_offset == 0)
1307 continue;
1308 #endif
1309 memcpy (new_base + addr, old_base + addr, sizeof(ElfW(Addr)));
1312 break;
1316 /* Write out new_file, and free the buffers. */
1318 if (write (new_file, new_base, new_file_size) != new_file_size)
1319 #ifndef emacs
1320 fatal ("Didn't write %d bytes: errno %d\n",
1321 new_file_size, errno);
1322 #else
1323 fatal ("Didn't write %d bytes to %s: errno %d\n",
1324 new_file_size, new_name, errno);
1325 #endif
1326 munmap (old_base, old_file_size);
1327 munmap (new_base, new_file_size);
1329 /* Close the files and make the new file executable. */
1331 #if MAP_ANON == 0
1332 close (mmap_fd);
1333 #endif
1335 if (close (old_file))
1336 fatal ("Can't close (%s): errno %d\n", old_name, errno);
1338 if (close (new_file))
1339 fatal ("Can't close (%s): errno %d\n", new_name, errno);
1341 if (stat (new_name, &stat_buf) == -1)
1342 fatal ("Can't stat (%s): errno %d\n", new_name, errno);
1344 n = umask (777);
1345 umask (n);
1346 stat_buf.st_mode |= 0111 & ~n;
1347 if (chmod (new_name, stat_buf.st_mode) == -1)
1348 fatal ("Can't chmod (%s): errno %d\n", new_name, errno);
1351 /* arch-tag: e02e1512-95e2-4ef0-bba7-b6bce658f1e3
1352 (do not change this comment) */