package.el (package--get-deps): Fix for indirect dependencies.
[emacs.git] / src / unexelf.c
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1 /* Copyright (C) 1985-1988, 1990, 1992, 1999-2015 Free Software
2 Foundation, Inc.
4 This file is part of GNU Emacs.
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 3 of the License, or
9 (at your option) any later version.
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.
16 You should have received a copy of the GNU General Public License
17 along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */
20 In other words, you are welcome to use, share and improve this program.
21 You are forbidden to forbid anyone else to use, share and improve
22 what you give them. Help stamp out software-hoarding! */
26 * unexec.c - Convert a running program into an a.out file.
28 * Author: Spencer W. Thomas
29 * Computer Science Dept.
30 * University of Utah
31 * Date: Tue Mar 2 1982
32 * Modified heavily since then.
34 * Synopsis:
35 * unexec (const char *new_name, const char *old_name);
37 * Takes a snapshot of the program and makes an a.out format file in the
38 * file named by the string argument new_name.
39 * If old_name is non-NULL, the symbol table will be taken from the given file.
40 * On some machines, an existing old_name file is required.
44 /* Even more heavily modified by james@bigtex.cactus.org of Dell Computer Co.
45 * ELF support added.
47 * Basic theory: the data space of the running process needs to be
48 * dumped to the output file. Normally we would just enlarge the size
49 * of .data, scooting everything down. But we can't do that in ELF,
50 * because there is often something between the .data space and the
51 * .bss space.
53 * In the temacs dump below, notice that the Global Offset Table
54 * (.got) and the Dynamic link data (.dynamic) come between .data1 and
55 * .bss. It does not work to overlap .data with these fields.
57 * The solution is to create a new .data segment. This segment is
58 * filled with data from the current process. Since the contents of
59 * various sections refer to sections by index, the new .data segment
60 * is made the last in the table to avoid changing any existing index.
62 * This is an example of how the section headers are changed. "Addr"
63 * is a process virtual address. "Offset" is a file offset.
65 raid:/nfs/raid/src/dist-18.56/src> dump -h temacs
67 temacs:
69 **** SECTION HEADER TABLE ****
70 [No] Type Flags Addr Offset Size Name
71 Link Info Adralgn Entsize
73 [1] 1 2 0x80480d4 0xd4 0x13 .interp
74 0 0 0x1 0
76 [2] 5 2 0x80480e8 0xe8 0x388 .hash
77 3 0 0x4 0x4
79 [3] 11 2 0x8048470 0x470 0x7f0 .dynsym
80 4 1 0x4 0x10
82 [4] 3 2 0x8048c60 0xc60 0x3ad .dynstr
83 0 0 0x1 0
85 [5] 9 2 0x8049010 0x1010 0x338 .rel.plt
86 3 7 0x4 0x8
88 [6] 1 6 0x8049348 0x1348 0x3 .init
89 0 0 0x4 0
91 [7] 1 6 0x804934c 0x134c 0x680 .plt
92 0 0 0x4 0x4
94 [8] 1 6 0x80499cc 0x19cc 0x3c56f .text
95 0 0 0x4 0
97 [9] 1 6 0x8085f3c 0x3df3c 0x3 .fini
98 0 0 0x4 0
100 [10] 1 2 0x8085f40 0x3df40 0x69c .rodata
101 0 0 0x4 0
103 [11] 1 2 0x80865dc 0x3e5dc 0xd51 .rodata1
104 0 0 0x4 0
106 [12] 1 3 0x8088330 0x3f330 0x20afc .data
107 0 0 0x4 0
109 [13] 1 3 0x80a8e2c 0x5fe2c 0x89d .data1
110 0 0 0x4 0
112 [14] 1 3 0x80a96cc 0x606cc 0x1a8 .got
113 0 0 0x4 0x4
115 [15] 6 3 0x80a9874 0x60874 0x80 .dynamic
116 4 0 0x4 0x8
118 [16] 8 3 0x80a98f4 0x608f4 0x449c .bss
119 0 0 0x4 0
121 [17] 2 0 0 0x608f4 0x9b90 .symtab
122 18 371 0x4 0x10
124 [18] 3 0 0 0x6a484 0x8526 .strtab
125 0 0 0x1 0
127 [19] 3 0 0 0x729aa 0x93 .shstrtab
128 0 0 0x1 0
130 [20] 1 0 0 0x72a3d 0x68b7 .comment
131 0 0 0x1 0
133 raid:/nfs/raid/src/dist-18.56/src> dump -h xemacs
135 xemacs:
137 **** SECTION HEADER TABLE ****
138 [No] Type Flags Addr Offset Size Name
139 Link Info Adralgn Entsize
141 [1] 1 2 0x80480d4 0xd4 0x13 .interp
142 0 0 0x1 0
144 [2] 5 2 0x80480e8 0xe8 0x388 .hash
145 3 0 0x4 0x4
147 [3] 11 2 0x8048470 0x470 0x7f0 .dynsym
148 4 1 0x4 0x10
150 [4] 3 2 0x8048c60 0xc60 0x3ad .dynstr
151 0 0 0x1 0
153 [5] 9 2 0x8049010 0x1010 0x338 .rel.plt
154 3 7 0x4 0x8
156 [6] 1 6 0x8049348 0x1348 0x3 .init
157 0 0 0x4 0
159 [7] 1 6 0x804934c 0x134c 0x680 .plt
160 0 0 0x4 0x4
162 [8] 1 6 0x80499cc 0x19cc 0x3c56f .text
163 0 0 0x4 0
165 [9] 1 6 0x8085f3c 0x3df3c 0x3 .fini
166 0 0 0x4 0
168 [10] 1 2 0x8085f40 0x3df40 0x69c .rodata
169 0 0 0x4 0
171 [11] 1 2 0x80865dc 0x3e5dc 0xd51 .rodata1
172 0 0 0x4 0
174 [12] 1 3 0x8088330 0x3f330 0x20afc .data
175 0 0 0x4 0
177 [13] 1 3 0x80a8e2c 0x5fe2c 0x89d .data1
178 0 0 0x4 0
180 [14] 1 3 0x80a96cc 0x606cc 0x1a8 .got
181 0 0 0x4 0x4
183 [15] 6 3 0x80a9874 0x60874 0x80 .dynamic
184 4 0 0x4 0x8
186 [16] 8 3 0x80c6800 0x7d800 0 .bss
187 0 0 0x4 0
189 [17] 2 0 0 0x7d800 0x9b90 .symtab
190 18 371 0x4 0x10
192 [18] 3 0 0 0x87390 0x8526 .strtab
193 0 0 0x1 0
195 [19] 3 0 0 0x8f8b6 0x93 .shstrtab
196 0 0 0x1 0
198 [20] 1 0 0 0x8f949 0x68b7 .comment
199 0 0 0x1 0
201 [21] 1 3 0x80a98f4 0x608f4 0x1cf0c .data
202 0 0 0x4 0
204 * This is an example of how the file header is changed. "Shoff" is
205 * the section header offset within the file. Since that table is
206 * after the new .data section, it is moved. "Shnum" is the number of
207 * sections, which we increment.
209 * "Phoff" is the file offset to the program header. "Phentsize" and
210 * "Shentsz" are the program and section header entries sizes respectively.
211 * These can be larger than the apparent struct sizes.
213 raid:/nfs/raid/src/dist-18.56/src> dump -f temacs
215 temacs:
217 **** ELF HEADER ****
218 Class Data Type Machine Version
219 Entry Phoff Shoff Flags Ehsize
220 Phentsize Phnum Shentsz Shnum Shstrndx
222 1 1 2 3 1
223 0x80499cc 0x34 0x792f4 0 0x34
224 0x20 5 0x28 21 19
226 raid:/nfs/raid/src/dist-18.56/src> dump -f xemacs
228 xemacs:
230 **** ELF HEADER ****
231 Class Data Type Machine Version
232 Entry Phoff Shoff Flags Ehsize
233 Phentsize Phnum Shentsz Shnum Shstrndx
235 1 1 2 3 1
236 0x80499cc 0x34 0x96200 0 0x34
237 0x20 5 0x28 22 19
239 * These are the program headers. "Offset" is the file offset to the
240 * segment. "Vaddr" is the memory load address. "Filesz" is the
241 * segment size as it appears in the file, and "Memsz" is the size in
242 * memory. Below, the third segment is the code and the fourth is the
243 * data: the difference between Filesz and Memsz is .bss
245 raid:/nfs/raid/src/dist-18.56/src> dump -o temacs
247 temacs:
248 ***** PROGRAM EXECUTION HEADER *****
249 Type Offset Vaddr Paddr
250 Filesz Memsz Flags Align
252 6 0x34 0x8048034 0
253 0xa0 0xa0 5 0
255 3 0xd4 0 0
256 0x13 0 4 0
258 1 0x34 0x8048034 0
259 0x3f2f9 0x3f2f9 5 0x1000
261 1 0x3f330 0x8088330 0
262 0x215c4 0x25a60 7 0x1000
264 2 0x60874 0x80a9874 0
265 0x80 0 7 0
267 raid:/nfs/raid/src/dist-18.56/src> dump -o xemacs
269 xemacs:
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 0x3e4d0 0x3e4d0 7 0x1000
286 2 0x60874 0x80a9874 0
287 0x80 0 7 0
292 /* Modified by wtien@urbana.mcd.mot.com of Motorola Inc.
294 * The above mechanism does not work if the unexeced ELF file is being
295 * re-layout by other applications (such as `strip'). All the applications
296 * that re-layout the internal of ELF will layout all sections in ascending
297 * order of their file offsets. After the re-layout, the data2 section will
298 * still be the LAST section in the section header vector, but its file offset
299 * is now being pushed far away down, and causes part of it not to be mapped
300 * in (ie. not covered by the load segment entry in PHDR vector), therefore
301 * causes the new binary to fail.
303 * The solution is to modify the unexec algorithm to insert the new data2
304 * section header right before the new bss section header, so their file
305 * offsets will be in the ascending order. Since some of the section's (all
306 * sections AFTER the bss section) indexes are now changed, we also need to
307 * modify some fields to make them point to the right sections. This is done
308 * by macro PATCH_INDEX. All the fields that need to be patched are:
310 * 1. ELF header e_shstrndx field.
311 * 2. section header sh_link and sh_info field.
312 * 3. symbol table entry st_shndx field.
314 * The above example now should look like:
316 **** SECTION HEADER TABLE ****
317 [No] Type Flags Addr Offset Size Name
318 Link Info Adralgn Entsize
320 [1] 1 2 0x80480d4 0xd4 0x13 .interp
321 0 0 0x1 0
323 [2] 5 2 0x80480e8 0xe8 0x388 .hash
324 3 0 0x4 0x4
326 [3] 11 2 0x8048470 0x470 0x7f0 .dynsym
327 4 1 0x4 0x10
329 [4] 3 2 0x8048c60 0xc60 0x3ad .dynstr
330 0 0 0x1 0
332 [5] 9 2 0x8049010 0x1010 0x338 .rel.plt
333 3 7 0x4 0x8
335 [6] 1 6 0x8049348 0x1348 0x3 .init
336 0 0 0x4 0
338 [7] 1 6 0x804934c 0x134c 0x680 .plt
339 0 0 0x4 0x4
341 [8] 1 6 0x80499cc 0x19cc 0x3c56f .text
342 0 0 0x4 0
344 [9] 1 6 0x8085f3c 0x3df3c 0x3 .fini
345 0 0 0x4 0
347 [10] 1 2 0x8085f40 0x3df40 0x69c .rodata
348 0 0 0x4 0
350 [11] 1 2 0x80865dc 0x3e5dc 0xd51 .rodata1
351 0 0 0x4 0
353 [12] 1 3 0x8088330 0x3f330 0x20afc .data
354 0 0 0x4 0
356 [13] 1 3 0x80a8e2c 0x5fe2c 0x89d .data1
357 0 0 0x4 0
359 [14] 1 3 0x80a96cc 0x606cc 0x1a8 .got
360 0 0 0x4 0x4
362 [15] 6 3 0x80a9874 0x60874 0x80 .dynamic
363 4 0 0x4 0x8
365 [16] 1 3 0x80a98f4 0x608f4 0x1cf0c .data
366 0 0 0x4 0
368 [17] 8 3 0x80c6800 0x7d800 0 .bss
369 0 0 0x4 0
371 [18] 2 0 0 0x7d800 0x9b90 .symtab
372 19 371 0x4 0x10
374 [19] 3 0 0 0x87390 0x8526 .strtab
375 0 0 0x1 0
377 [20] 3 0 0 0x8f8b6 0x93 .shstrtab
378 0 0 0x1 0
380 [21] 1 0 0 0x8f949 0x68b7 .comment
381 0 0 0x1 0
385 /* We do not use mmap because that fails with NFS.
386 Instead we read the whole file, modify it, and write it out. */
388 #include <config.h>
389 #include "unexec.h"
390 #include "lisp.h"
392 #include <errno.h>
393 #include <fcntl.h>
394 #include <limits.h>
395 #include <memory.h>
396 #include <stdint.h>
397 #include <stdio.h>
398 #include <sys/stat.h>
399 #include <sys/types.h>
400 #include <unistd.h>
402 #if !defined (__NetBSD__) && !defined (__OpenBSD__)
403 #include <elf.h>
404 #endif /* not __NetBSD__ and not __OpenBSD__ */
405 #include <sys/mman.h>
406 #if defined (_SYSTYPE_SYSV)
407 #include <sys/elf_mips.h>
408 #include <sym.h>
409 #endif /* _SYSTYPE_SYSV */
410 #if __sgi
411 #include <syms.h> /* for HDRR declaration */
412 #endif /* __sgi */
414 #ifndef MAP_ANON
415 #ifdef MAP_ANONYMOUS
416 #define MAP_ANON MAP_ANONYMOUS
417 #else
418 #define MAP_ANON 0
419 #endif
420 #endif
422 #ifndef MAP_FAILED
423 #define MAP_FAILED ((void *) -1)
424 #endif
426 #if defined (__alpha__) && !defined (__NetBSD__) && !defined (__OpenBSD__)
427 /* Declare COFF debugging symbol table. This used to be in
428 /usr/include/sym.h, but this file is no longer included in Red Hat
429 5.0 and presumably in any other glibc 2.x based distribution. */
430 typedef struct {
431 short magic;
432 short vstamp;
433 int ilineMax;
434 int idnMax;
435 int ipdMax;
436 int isymMax;
437 int ioptMax;
438 int iauxMax;
439 int issMax;
440 int issExtMax;
441 int ifdMax;
442 int crfd;
443 int iextMax;
444 long cbLine;
445 long cbLineOffset;
446 long cbDnOffset;
447 long cbPdOffset;
448 long cbSymOffset;
449 long cbOptOffset;
450 long cbAuxOffset;
451 long cbSsOffset;
452 long cbSsExtOffset;
453 long cbFdOffset;
454 long cbRfdOffset;
455 long cbExtOffset;
456 } HDRR, *pHDRR;
457 #define cbHDRR sizeof (HDRR)
458 #define hdrNil ((pHDRR)0)
459 #endif
461 #ifdef __NetBSD__
463 * NetBSD does not have normal-looking user-land ELF support.
465 # if defined __alpha__ || defined __sparc_v9__ || defined _LP64
466 # define ELFSIZE 64
467 # else
468 # define ELFSIZE 32
469 # endif
470 # include <sys/exec_elf.h>
472 # ifndef PT_LOAD
473 # define PT_LOAD Elf_pt_load
474 # if 0 /* was in pkgsrc patches for 20.7 */
475 # define SHT_PROGBITS Elf_sht_progbits
476 # endif
477 # define SHT_SYMTAB Elf_sht_symtab
478 # define SHT_DYNSYM Elf_sht_dynsym
479 # define SHT_NULL Elf_sht_null
480 # define SHT_NOBITS Elf_sht_nobits
481 # define SHT_REL Elf_sht_rel
482 # define SHT_RELA Elf_sht_rela
484 # define SHN_UNDEF Elf_eshn_undefined
485 # define SHN_ABS Elf_eshn_absolute
486 # define SHN_COMMON Elf_eshn_common
487 # endif /* !PT_LOAD */
489 # ifdef __alpha__
490 # include <sys/exec_ecoff.h>
491 # define HDRR struct ecoff_symhdr
492 # define pHDRR HDRR *
493 # endif /* __alpha__ */
495 #ifdef __mips__ /* was in pkgsrc patches for 20.7 */
496 # define SHT_MIPS_DEBUG DT_MIPS_FLAGS
497 # define HDRR struct Elf_Shdr
498 #endif /* __mips__ */
499 #endif /* __NetBSD__ */
501 #ifdef __OpenBSD__
502 # include <sys/exec_elf.h>
503 #endif
505 #if __GNU_LIBRARY__ - 0 >= 6
506 # include <link.h> /* get ElfW etc */
507 #endif
509 #ifndef ElfW
510 # define ElfBitsW(bits, type) Elf##bits##_##type
511 # ifndef ELFSIZE
512 # ifdef _LP64
513 # define ELFSIZE 64
514 # else
515 # define ELFSIZE 32
516 # endif
517 # endif
518 /* This macro expands `bits' before invoking ElfBitsW. */
519 # define ElfExpandBitsW(bits, type) ElfBitsW (bits, type)
520 # define ElfW(type) ElfExpandBitsW (ELFSIZE, type)
521 #endif
523 /* The code often converts ElfW (Half) values like e_shentsize to ptrdiff_t;
524 check that this doesn't lose information. */
525 #include <intprops.h>
526 #include <verify.h>
527 verify ((! TYPE_SIGNED (ElfW (Half))
528 || PTRDIFF_MIN <= TYPE_MINIMUM (ElfW (Half)))
529 && TYPE_MAXIMUM (ElfW (Half)) <= PTRDIFF_MAX);
531 #ifdef UNEXELF_DEBUG
532 # define DEBUG_LOG(expr) fprintf (stderr, #expr " 0x%jx\n", (uintmax_t) (expr))
533 #endif
535 /* Get the address of a particular section or program header entry,
536 * accounting for the size of the entries.
539 On PPC Reference Platform running Solaris 2.5.1
540 the plt section is also of type NOBI like the bss section.
541 (not really stored) and therefore sections after the bss
542 section start at the plt offset. The plt section is always
543 the one just before the bss section.
544 Thus, we modify the test from
545 if (NEW_SECTION_H (nn).sh_offset >= new_data2_offset)
547 if (NEW_SECTION_H (nn).sh_offset >=
548 OLD_SECTION_H (old_bss_index-1).sh_offset)
549 This is just a hack. We should put the new data section
550 before the .plt section.
551 And we should not have this routine at all but use
552 the libelf library to read the old file and create the new
553 file.
554 The changed code is minimal and depends on prep set in m/prep.h
555 Erik Deumens
556 Quantum Theory Project
557 University of Florida
558 deumens@qtp.ufl.edu
559 Apr 23, 1996
562 static void *
563 entry_address (void *section_h, ptrdiff_t idx, ptrdiff_t entsize)
565 char *h = section_h;
566 return h + idx * entsize;
569 #define OLD_SECTION_H(n) \
570 (*(ElfW (Shdr) *) entry_address (old_section_h, n, old_file_h->e_shentsize))
571 #define NEW_SECTION_H(n) \
572 (*(ElfW (Shdr) *) entry_address (new_section_h, n, new_file_h->e_shentsize))
573 #define NEW_PROGRAM_H(n) \
574 (*(ElfW (Phdr) *) entry_address (new_program_h, n, new_file_h->e_phentsize))
576 #define PATCH_INDEX(n) ((n) += old_bss_index <= (n))
577 typedef unsigned char byte;
579 /* Round X up to a multiple of Y. */
581 static ElfW (Addr)
582 round_up (ElfW (Addr) x, ElfW (Addr) y)
584 ElfW (Addr) rem = x % y;
585 if (rem == 0)
586 return x;
587 return x - rem + y;
590 /* Return the index of the section named NAME.
591 SECTION_NAMES, FILE_NAME and FILE_H give information
592 about the file we are looking in.
594 If we don't find the section NAME, that is a fatal error
595 if NOERROR is false; return -1 if NOERROR is true. */
597 static ptrdiff_t
598 find_section (const char *name, const char *section_names, const char *file_name,
599 ElfW (Ehdr) *old_file_h, ElfW (Shdr) *old_section_h,
600 bool noerror)
602 ptrdiff_t idx;
604 for (idx = 1; idx < old_file_h->e_shnum; idx++)
606 char const *found_name = section_names + OLD_SECTION_H (idx).sh_name;
607 #ifdef UNEXELF_DEBUG
608 fprintf (stderr, "Looking for %s - found %s\n", name, found_name);
609 #endif
610 if (strcmp (name, found_name) == 0)
611 return idx;
614 if (! noerror)
615 fatal ("Can't find %s in %s", name, file_name);
616 return -1;
619 /* ****************************************************************
620 * unexec
622 * driving logic.
624 * In ELF, this works by replacing the old .bss section with a new
625 * .data section, and inserting an empty .bss immediately afterwards.
628 void
629 unexec (const char *new_name, const char *old_name)
631 int new_file, old_file;
632 off_t new_file_size;
633 void *new_break;
635 /* Pointers to the base of the image of the two files. */
636 caddr_t old_base, new_base;
638 #if MAP_ANON == 0
639 int mmap_fd;
640 #else
641 # define mmap_fd -1
642 #endif
644 /* Pointers to the file, program and section headers for the old and
645 new files. */
646 ElfW (Ehdr) *old_file_h, *new_file_h;
647 ElfW (Phdr) *old_program_h, *new_program_h;
648 ElfW (Shdr) *old_section_h, *new_section_h;
650 /* Point to the section name table in the old file. */
651 char *old_section_names;
653 ElfW (Addr) old_bss_addr, new_bss_addr;
654 ElfW (Word) old_bss_size, new_data2_size;
655 ElfW (Off) new_data2_offset;
656 ElfW (Addr) new_data2_addr;
657 ElfW (Off) old_bss_offset;
658 ElfW (Word) new_data2_incr;
660 ptrdiff_t n, nn;
661 ptrdiff_t old_bss_index, old_sbss_index, old_plt_index;
662 ptrdiff_t old_data_index, new_data2_index;
663 #if defined _SYSTYPE_SYSV || defined __sgi
664 ptrdiff_t old_mdebug_index;
665 #endif
666 struct stat stat_buf;
667 off_t old_file_size;
669 /* Open the old file, allocate a buffer of the right size, and read
670 in the file contents. */
672 old_file = emacs_open (old_name, O_RDONLY, 0);
674 if (old_file < 0)
675 fatal ("Can't open %s for reading: %s", old_name, strerror (errno));
677 if (fstat (old_file, &stat_buf) != 0)
678 fatal ("Can't fstat (%s): %s", old_name, strerror (errno));
680 #if MAP_ANON == 0
681 mmap_fd = emacs_open ("/dev/zero", O_RDONLY, 0);
682 if (mmap_fd < 0)
683 fatal ("Can't open /dev/zero for reading: %s", strerror (errno));
684 #endif
686 /* We cannot use malloc here because that may use sbrk. If it does,
687 we'd dump our temporary buffers with Emacs, and we'd have to be
688 extra careful to use the correct value of sbrk(0) after
689 allocating all buffers in the code below, which we aren't. */
690 old_file_size = stat_buf.st_size;
691 if (! (0 <= old_file_size && old_file_size <= SIZE_MAX))
692 fatal ("File size out of range");
693 old_base = mmap (NULL, old_file_size, PROT_READ | PROT_WRITE,
694 MAP_ANON | MAP_PRIVATE, mmap_fd, 0);
695 if (old_base == MAP_FAILED)
696 fatal ("Can't allocate buffer for %s: %s", old_name, strerror (errno));
698 if (read (old_file, old_base, old_file_size) != old_file_size)
699 fatal ("Didn't read all of %s: %s", old_name, strerror (errno));
701 /* Get pointers to headers & section names */
703 old_file_h = (ElfW (Ehdr) *) old_base;
704 old_program_h = (ElfW (Phdr) *) ((byte *) old_base + old_file_h->e_phoff);
705 old_section_h = (ElfW (Shdr) *) ((byte *) old_base + old_file_h->e_shoff);
706 old_section_names = (char *) old_base
707 + OLD_SECTION_H (old_file_h->e_shstrndx).sh_offset;
709 /* Find the mdebug section, if any. */
711 #if defined _SYSTYPE_SYSV || defined __sgi
712 old_mdebug_index = find_section (".mdebug", old_section_names,
713 old_name, old_file_h, old_section_h, 1);
714 #endif
716 /* Find the old .bss section. Figure out parameters of the new
717 data2 and bss sections. */
719 old_bss_index = find_section (".bss", old_section_names,
720 old_name, old_file_h, old_section_h, 0);
722 old_sbss_index = find_section (".sbss", old_section_names,
723 old_name, old_file_h, old_section_h, 1);
724 if (old_sbss_index != -1)
725 if (OLD_SECTION_H (old_sbss_index).sh_type != SHT_NOBITS)
726 old_sbss_index = -1;
728 /* PowerPC64 has .plt in the BSS section. */
729 old_plt_index = find_section (".plt", old_section_names,
730 old_name, old_file_h, old_section_h, 1);
731 if (old_plt_index != -1)
732 if (OLD_SECTION_H (old_plt_index).sh_type != SHT_NOBITS)
733 old_plt_index = -1;
735 if (old_sbss_index == -1 && old_plt_index == -1)
737 old_bss_addr = OLD_SECTION_H (old_bss_index).sh_addr;
738 old_bss_size = OLD_SECTION_H (old_bss_index).sh_size;
739 old_bss_offset = OLD_SECTION_H (old_bss_index).sh_offset;
740 new_data2_index = old_bss_index;
742 else if (old_plt_index != -1
743 && (old_sbss_index == -1
744 || (OLD_SECTION_H (old_sbss_index).sh_addr
745 > OLD_SECTION_H (old_plt_index).sh_addr)))
747 old_bss_addr = OLD_SECTION_H (old_plt_index).sh_addr;
748 old_bss_size = OLD_SECTION_H (old_bss_index).sh_size
749 + OLD_SECTION_H (old_plt_index).sh_size;
750 if (old_sbss_index != -1)
751 old_bss_size += OLD_SECTION_H (old_sbss_index).sh_size;
752 old_bss_offset = OLD_SECTION_H (old_plt_index).sh_offset;
753 new_data2_index = old_plt_index;
755 else
757 old_bss_addr = OLD_SECTION_H (old_sbss_index).sh_addr;
758 old_bss_size = OLD_SECTION_H (old_bss_index).sh_size
759 + OLD_SECTION_H (old_sbss_index).sh_size;
760 old_bss_offset = OLD_SECTION_H (old_sbss_index).sh_offset;
761 new_data2_index = old_sbss_index;
764 /* Find the old .data section. Figure out parameters of
765 the new data2 and bss sections. */
767 old_data_index = find_section (".data", old_section_names,
768 old_name, old_file_h, old_section_h, 0);
770 new_break = sbrk (0);
771 new_bss_addr = (ElfW (Addr)) new_break;
772 new_data2_addr = old_bss_addr;
773 new_data2_size = new_bss_addr - old_bss_addr;
774 new_data2_offset = OLD_SECTION_H (old_data_index).sh_offset
775 + (new_data2_addr - OLD_SECTION_H (old_data_index).sh_addr);
776 /* This is the amount by which the sections following the bss sections
777 must be shifted in the image. It can differ from new_data2_size if
778 the end of the old .data section (and thus the offset of the .bss
779 section) was unaligned. */
780 new_data2_incr = new_data2_size + (new_data2_offset - old_bss_offset);
782 #ifdef UNEXELF_DEBUG
783 fprintf (stderr, "old_bss_index %td\n", old_bss_index);
784 DEBUG_LOG (old_bss_addr);
785 DEBUG_LOG (old_bss_size);
786 DEBUG_LOG (old_bss_offset);
787 DEBUG_LOG (new_bss_addr);
788 DEBUG_LOG (new_data2_addr);
789 DEBUG_LOG (new_data2_size);
790 DEBUG_LOG (new_data2_offset);
791 DEBUG_LOG (new_data2_incr);
792 #endif
794 if (new_bss_addr < old_bss_addr + old_bss_size)
795 fatal (".bss shrank when undumping");
797 /* Set the output file to the right size. Allocate a buffer to hold
798 the image of the new file. Set pointers to various interesting
799 objects. */
801 new_file = emacs_open (new_name, O_RDWR | O_CREAT, 0777);
802 if (new_file < 0)
803 fatal ("Can't creat (%s): %s", new_name, strerror (errno));
805 new_file_size = old_file_size + old_file_h->e_shentsize + new_data2_incr;
807 if (ftruncate (new_file, new_file_size))
808 fatal ("Can't ftruncate (%s): %s", new_name, strerror (errno));
810 new_base = mmap (NULL, new_file_size, PROT_READ | PROT_WRITE,
811 MAP_ANON | MAP_PRIVATE, mmap_fd, 0);
812 if (new_base == MAP_FAILED)
813 fatal ("Can't allocate buffer for %s: %s", old_name, strerror (errno));
815 new_file_h = (ElfW (Ehdr) *) new_base;
816 new_program_h = (ElfW (Phdr) *) ((byte *) new_base + old_file_h->e_phoff);
817 new_section_h = (ElfW (Shdr) *)
818 ((byte *) new_base + old_file_h->e_shoff + new_data2_incr);
820 /* Make our new file, program and section headers as copies of the
821 originals. */
823 memcpy (new_file_h, old_file_h, old_file_h->e_ehsize);
824 memcpy (new_program_h, old_program_h,
825 old_file_h->e_phnum * old_file_h->e_phentsize);
827 /* Modify the e_shstrndx if necessary. */
828 PATCH_INDEX (new_file_h->e_shstrndx);
830 /* Fix up file header. We'll add one section. Section header is
831 further away now. */
833 new_file_h->e_shoff += new_data2_incr;
834 new_file_h->e_shnum += 1;
836 #ifdef UNEXELF_DEBUG
837 DEBUG_LOG (old_file_h->e_shoff);
838 fprintf (stderr, "Old section count %td\n", (ptrdiff_t) old_file_h->e_shnum);
839 DEBUG_LOG (new_file_h->e_shoff);
840 fprintf (stderr, "New section count %td\n", (ptrdiff_t) new_file_h->e_shnum);
841 #endif
843 /* Fix up a new program header. Extend the writable data segment so
844 that the bss area is covered too. Find that segment by looking
845 for a segment that ends just before the .bss area. Make sure
846 that no segments are above the new .data2. Put a loop at the end
847 to adjust the offset and address of any segment that is above
848 data2, just in case we decide to allow this later. */
850 for (n = new_file_h->e_phnum; --n >= 0; )
852 /* Compute maximum of all requirements for alignment of section. */
853 ElfW (Word) alignment = (NEW_PROGRAM_H (n)).p_align;
854 if ((OLD_SECTION_H (old_bss_index)).sh_addralign > alignment)
855 alignment = OLD_SECTION_H (old_bss_index).sh_addralign;
857 #ifdef __sgi
858 /* According to r02kar@x4u2.desy.de (Karsten Kuenne)
859 and oliva@gnu.org (Alexandre Oliva), on IRIX 5.2, we
860 always get "Program segment above .bss" when dumping
861 when the executable doesn't have an sbss section. */
862 if (old_sbss_index != -1)
863 #endif /* __sgi */
864 if (NEW_PROGRAM_H (n).p_vaddr + NEW_PROGRAM_H (n).p_filesz
865 > (old_sbss_index == -1
866 ? old_bss_addr
867 : round_up (old_bss_addr, alignment)))
868 fatal ("Program segment above .bss in %s", old_name);
870 if (NEW_PROGRAM_H (n).p_type == PT_LOAD
871 && (round_up ((NEW_PROGRAM_H (n)).p_vaddr
872 + (NEW_PROGRAM_H (n)).p_filesz,
873 alignment)
874 == round_up (old_bss_addr, alignment)))
875 break;
877 if (n < 0)
878 fatal ("Couldn't find segment next to .bss in %s", old_name);
880 /* Make sure that the size includes any padding before the old .bss
881 section. */
882 NEW_PROGRAM_H (n).p_filesz = new_bss_addr - NEW_PROGRAM_H (n).p_vaddr;
883 NEW_PROGRAM_H (n).p_memsz = NEW_PROGRAM_H (n).p_filesz;
885 #if 0 /* Maybe allow section after data2 - does this ever happen? */
886 for (n = new_file_h->e_phnum; --n >= 0; )
888 if (NEW_PROGRAM_H (n).p_vaddr
889 && NEW_PROGRAM_H (n).p_vaddr >= new_data2_addr)
890 NEW_PROGRAM_H (n).p_vaddr += new_data2_size - old_bss_size;
892 if (NEW_PROGRAM_H (n).p_offset >= new_data2_offset)
893 NEW_PROGRAM_H (n).p_offset += new_data2_incr;
895 #endif
897 /* Fix up section headers based on new .data2 section. Any section
898 whose offset or virtual address is after the new .data2 section
899 gets its value adjusted. .bss size becomes zero and new address
900 is set. data2 section header gets added by copying the existing
901 .data header and modifying the offset, address and size. */
903 /* Walk through all section headers, insert the new data2 section right
904 before the new bss section. */
905 for (n = 1, nn = 1; n < old_file_h->e_shnum; n++, nn++)
907 caddr_t src;
908 /* If it is (s)bss section, insert the new data2 section before it. */
909 /* new_data2_index is the index of either old_sbss or old_bss, that was
910 chosen as a section for new_data2. */
911 if (n == new_data2_index)
913 /* Steal the data section header for this data2 section. */
914 memcpy (&NEW_SECTION_H (nn), &OLD_SECTION_H (old_data_index),
915 new_file_h->e_shentsize);
917 NEW_SECTION_H (nn).sh_addr = new_data2_addr;
918 NEW_SECTION_H (nn).sh_offset = new_data2_offset;
919 NEW_SECTION_H (nn).sh_size = new_data2_size;
920 /* Use the bss section's alignment. This will assure that the
921 new data2 section always be placed in the same spot as the old
922 bss section by any other application. */
923 NEW_SECTION_H (nn).sh_addralign = OLD_SECTION_H (n).sh_addralign;
925 /* Now copy over what we have in the memory now. */
926 memcpy (NEW_SECTION_H (nn).sh_offset + new_base,
927 (caddr_t) OLD_SECTION_H (n).sh_addr,
928 new_data2_size);
929 nn++;
932 memcpy (&NEW_SECTION_H (nn), &OLD_SECTION_H (n),
933 old_file_h->e_shentsize);
935 if (n == old_bss_index
936 /* The new bss and sbss section's size is zero, and its file offset
937 and virtual address should be off by NEW_DATA2_SIZE. */
938 || n == old_sbss_index || n == old_plt_index
941 /* NN should be `old_s?bss_index + 1' at this point. */
942 NEW_SECTION_H (nn).sh_offset = new_data2_offset + new_data2_size;
943 NEW_SECTION_H (nn).sh_addr = new_data2_addr + new_data2_size;
944 /* Let the new bss section address alignment be the same as the
945 section address alignment followed the old bss section, so
946 this section will be placed in exactly the same place. */
947 NEW_SECTION_H (nn).sh_addralign = OLD_SECTION_H (nn).sh_addralign;
948 NEW_SECTION_H (nn).sh_size = 0;
950 else
952 /* Any section that was originally placed after the .bss
953 section should now be off by NEW_DATA2_INCR. If a
954 section overlaps the .bss section, consider it to be
955 placed after the .bss section. Overlap can occur if the
956 section just before .bss has less-strict alignment; this
957 was observed between .symtab and .bss on Solaris 2.5.1
958 (sparc) with GCC snapshot 960602.
960 > dump -h temacs
962 temacs:
964 **** SECTION HEADER TABLE ****
965 [No] Type Flags Addr Offset Size Name
966 Link Info Adralgn Entsize
968 [22] 1 3 0x335150 0x315150 0x4 .data.rel.local
969 0 0 0x4 0
971 [23] 8 3 0x335158 0x315158 0x42720 .bss
972 0 0 0x8 0
974 [24] 2 0 0 0x315154 0x1c9d0 .symtab
975 25 1709 0x4 0x10
978 if (NEW_SECTION_H (nn).sh_offset >= old_bss_offset
979 || (NEW_SECTION_H (nn).sh_offset + NEW_SECTION_H (nn).sh_size
980 > new_data2_offset))
981 NEW_SECTION_H (nn).sh_offset += new_data2_incr;
983 /* Any section that was originally placed after the section
984 header table should now be off by the size of one section
985 header table entry. */
986 if (NEW_SECTION_H (nn).sh_offset > new_file_h->e_shoff)
987 NEW_SECTION_H (nn).sh_offset += new_file_h->e_shentsize;
990 /* If any section hdr refers to the section after the new .data
991 section, make it refer to next one because we have inserted
992 a new section in between. */
994 PATCH_INDEX (NEW_SECTION_H (nn).sh_link);
995 /* For symbol tables, info is a symbol table index,
996 so don't change it. */
997 if (NEW_SECTION_H (nn).sh_type != SHT_SYMTAB
998 && NEW_SECTION_H (nn).sh_type != SHT_DYNSYM)
999 PATCH_INDEX (NEW_SECTION_H (nn).sh_info);
1001 if (old_sbss_index != -1)
1002 if (!strcmp (old_section_names + NEW_SECTION_H (nn).sh_name, ".sbss"))
1004 NEW_SECTION_H (nn).sh_offset =
1005 round_up (NEW_SECTION_H (nn).sh_offset,
1006 NEW_SECTION_H (nn).sh_addralign);
1007 NEW_SECTION_H (nn).sh_type = SHT_PROGBITS;
1010 /* Now, start to copy the content of sections. */
1011 if (NEW_SECTION_H (nn).sh_type == SHT_NULL
1012 || NEW_SECTION_H (nn).sh_type == SHT_NOBITS)
1013 continue;
1015 /* Write out the sections. .data and .data1 (and data2, called
1016 ".data" in the strings table) get copied from the current process
1017 instead of the old file. */
1018 if (!strcmp (old_section_names + NEW_SECTION_H (n).sh_name, ".data")
1019 || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name),
1020 ".sdata")
1021 || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name),
1022 ".lit4")
1023 || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name),
1024 ".lit8")
1025 /* The conditional bit below was in Oliva's original code
1026 (1999-08-25) and seems to have been dropped by mistake
1027 subsequently. It prevents a crash at startup under X in
1028 `IRIX64 6.5 6.5.17m', whether compiled on that release or
1029 an earlier one. It causes no trouble on the other ELF
1030 platforms I could test (Irix 6.5.15m, Solaris 8, Debian
1031 Potato x86, Debian Woody SPARC); however, it's reported
1032 to cause crashes under some version of GNU/Linux. It's
1033 not yet clear what's changed in that Irix version to
1034 cause the problem, or why the fix sometimes fails under
1035 GNU/Linux. There's probably no good reason to have
1036 something Irix-specific here, but this will have to do
1037 for now. IRIX6_5 is the most specific macro we have to
1038 test. -- fx 2002-10-01
1040 The issue _looks_ as though it's gone away on 6.5.18m,
1041 but maybe it's still lurking, to be triggered by some
1042 change in the binary. It appears to concern the dynamic
1043 loader, but I never got anywhere with an SGI support call
1044 seeking clues. -- fx 2002-11-29. */
1045 #ifdef IRIX6_5
1046 || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name),
1047 ".got")
1048 #endif
1049 || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name),
1050 ".sdata1")
1051 || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name),
1052 ".data1")
1053 || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name),
1054 ".sbss"))
1055 src = (caddr_t) OLD_SECTION_H (n).sh_addr;
1056 else
1057 src = old_base + OLD_SECTION_H (n).sh_offset;
1059 memcpy (NEW_SECTION_H (nn).sh_offset + new_base, src,
1060 NEW_SECTION_H (nn).sh_size);
1062 #if defined __alpha__ && !defined __OpenBSD__
1063 /* Update Alpha COFF symbol table: */
1064 if (strcmp (old_section_names + OLD_SECTION_H (n).sh_name, ".mdebug")
1065 == 0)
1067 pHDRR symhdr = (pHDRR) (NEW_SECTION_H (nn).sh_offset + new_base);
1069 symhdr->cbLineOffset += new_data2_size;
1070 symhdr->cbDnOffset += new_data2_size;
1071 symhdr->cbPdOffset += new_data2_size;
1072 symhdr->cbSymOffset += new_data2_size;
1073 symhdr->cbOptOffset += new_data2_size;
1074 symhdr->cbAuxOffset += new_data2_size;
1075 symhdr->cbSsOffset += new_data2_size;
1076 symhdr->cbSsExtOffset += new_data2_size;
1077 symhdr->cbFdOffset += new_data2_size;
1078 symhdr->cbRfdOffset += new_data2_size;
1079 symhdr->cbExtOffset += new_data2_size;
1081 #endif /* __alpha__ && !__OpenBSD__ */
1083 #if defined (_SYSTYPE_SYSV)
1084 if (NEW_SECTION_H (nn).sh_type == SHT_MIPS_DEBUG
1085 && old_mdebug_index != -1)
1087 ptrdiff_t new_offset = NEW_SECTION_H (nn).sh_offset;
1088 ptrdiff_t old_offset = OLD_SECTION_H (old_mdebug_index).sh_offset;
1089 ptrdiff_t diff = new_offset - old_offset;
1090 HDRR *phdr = (HDRR *)(NEW_SECTION_H (nn).sh_offset + new_base);
1092 if (diff)
1094 phdr->cbLineOffset += diff;
1095 phdr->cbDnOffset += diff;
1096 phdr->cbPdOffset += diff;
1097 phdr->cbSymOffset += diff;
1098 phdr->cbOptOffset += diff;
1099 phdr->cbAuxOffset += diff;
1100 phdr->cbSsOffset += diff;
1101 phdr->cbSsExtOffset += diff;
1102 phdr->cbFdOffset += diff;
1103 phdr->cbRfdOffset += diff;
1104 phdr->cbExtOffset += diff;
1107 #endif /* _SYSTYPE_SYSV */
1109 #if __sgi
1110 /* Adjust the HDRR offsets in .mdebug and copy the
1111 line data if it's in its usual 'hole' in the object.
1112 Makes the new file debuggable with dbx.
1113 patches up two problems: the absolute file offsets
1114 in the HDRR record of .mdebug (see /usr/include/syms.h), and
1115 the ld bug that gets the line table in a hole in the
1116 elf file rather than in the .mdebug section proper.
1117 David Anderson. davea@sgi.com Jan 16,1994. */
1118 if (n == old_mdebug_index)
1120 #define MDEBUGADJUST(__ct,__fileaddr) \
1121 if (n_phdrr->__ct > 0) \
1123 n_phdrr->__fileaddr += movement; \
1126 HDRR * o_phdrr = (HDRR *)((byte *)old_base + OLD_SECTION_H (n).sh_offset);
1127 HDRR * n_phdrr = (HDRR *)((byte *)new_base + NEW_SECTION_H (nn).sh_offset);
1128 unsigned movement = new_data2_size;
1130 MDEBUGADJUST (idnMax, cbDnOffset);
1131 MDEBUGADJUST (ipdMax, cbPdOffset);
1132 MDEBUGADJUST (isymMax, cbSymOffset);
1133 MDEBUGADJUST (ioptMax, cbOptOffset);
1134 MDEBUGADJUST (iauxMax, cbAuxOffset);
1135 MDEBUGADJUST (issMax, cbSsOffset);
1136 MDEBUGADJUST (issExtMax, cbSsExtOffset);
1137 MDEBUGADJUST (ifdMax, cbFdOffset);
1138 MDEBUGADJUST (crfd, cbRfdOffset);
1139 MDEBUGADJUST (iextMax, cbExtOffset);
1140 /* The Line Section, being possible off in a hole of the object,
1141 requires special handling. */
1142 if (n_phdrr->cbLine > 0)
1144 if (o_phdrr->cbLineOffset > (OLD_SECTION_H (n).sh_offset
1145 + OLD_SECTION_H (n).sh_size))
1147 /* line data is in a hole in elf. do special copy and adjust
1148 for this ld mistake.
1150 n_phdrr->cbLineOffset += movement;
1152 memcpy (n_phdrr->cbLineOffset + new_base,
1153 o_phdrr->cbLineOffset + old_base, n_phdrr->cbLine);
1155 else
1157 /* somehow line data is in .mdebug as it is supposed to be. */
1158 MDEBUGADJUST (cbLine, cbLineOffset);
1162 #endif /* __sgi */
1164 /* If it is the symbol table, its st_shndx field needs to be patched. */
1165 if (NEW_SECTION_H (nn).sh_type == SHT_SYMTAB
1166 || NEW_SECTION_H (nn).sh_type == SHT_DYNSYM)
1168 ElfW (Shdr) *spt = &NEW_SECTION_H (nn);
1169 ptrdiff_t num = spt->sh_size / spt->sh_entsize;
1170 ElfW (Sym) * sym = (ElfW (Sym) *) (NEW_SECTION_H (nn).sh_offset +
1171 new_base);
1172 for (; num--; sym++)
1174 if ((sym->st_shndx == SHN_UNDEF)
1175 || (sym->st_shndx == SHN_ABS)
1176 || (sym->st_shndx == SHN_COMMON))
1177 continue;
1179 PATCH_INDEX (sym->st_shndx);
1184 /* Update the symbol values of _edata and _end. */
1185 for (n = new_file_h->e_shnum; 0 < --n; )
1187 byte *symnames;
1188 ElfW (Sym) *symp, *symendp;
1190 if (NEW_SECTION_H (n).sh_type != SHT_DYNSYM
1191 && NEW_SECTION_H (n).sh_type != SHT_SYMTAB)
1192 continue;
1194 symnames = ((byte *) new_base
1195 + NEW_SECTION_H (NEW_SECTION_H (n).sh_link).sh_offset);
1196 symp = (ElfW (Sym) *) (NEW_SECTION_H (n).sh_offset + new_base);
1197 symendp = (ElfW (Sym) *) ((byte *)symp + NEW_SECTION_H (n).sh_size);
1199 for (; symp < symendp; symp ++)
1201 if (strcmp ((char *) (symnames + symp->st_name), "_end") == 0
1202 || strcmp ((char *) (symnames + symp->st_name), "end") == 0
1203 || strcmp ((char *) (symnames + symp->st_name), "_edata") == 0
1204 || strcmp ((char *) (symnames + symp->st_name), "edata") == 0)
1205 memcpy (&symp->st_value, &new_bss_addr, sizeof (new_bss_addr));
1207 /* Strictly speaking, #ifdef below is not necessary. But we
1208 keep it to indicate that this kind of change may also be
1209 necessary for other unexecs to support GNUstep. */
1210 #ifdef NS_IMPL_GNUSTEP
1211 /* ObjC runtime modifies the values of some data structures
1212 such as classes and selectors in the .data section after
1213 loading. As the dump process copies the .data section
1214 from the current process, that causes problems when the
1215 modified classes are reinitialized in the dumped
1216 executable. We copy such data from the old file, not
1217 from the current process. */
1218 if (strncmp ((char *) (symnames + symp->st_name),
1219 "_OBJC_", sizeof ("_OBJC_") - 1) == 0)
1221 caddr_t old, new;
1223 new = ((symp->st_value - NEW_SECTION_H (symp->st_shndx).sh_addr)
1224 + NEW_SECTION_H (symp->st_shndx).sh_offset + new_base);
1225 /* "Unpatch" index. */
1226 nn = symp->st_shndx;
1227 if (nn > old_bss_index)
1228 nn--;
1229 if (nn == old_bss_index)
1230 memset (new, 0, symp->st_size);
1231 else
1233 old = ((symp->st_value
1234 - NEW_SECTION_H (symp->st_shndx).sh_addr)
1235 + OLD_SECTION_H (nn).sh_offset + old_base);
1236 memcpy (new, old, symp->st_size);
1239 #endif
1243 /* This loop seeks out relocation sections for the data section, so
1244 that it can undo relocations performed by the runtime linker. */
1245 for (n = new_file_h->e_shnum; 0 < --n; )
1247 ElfW (Shdr) section = NEW_SECTION_H (n);
1249 /* Cause a compilation error if anyone uses n instead of nn below. */
1250 #define n ((void) 0);
1251 n /* Prevent 'macro "n" is not used' warnings. */
1253 switch (section.sh_type)
1255 default:
1256 break;
1257 case SHT_REL:
1258 case SHT_RELA:
1259 /* This code handles two different size structs, but there should
1260 be no harm in that provided that r_offset is always the first
1261 member. */
1262 nn = section.sh_info;
1263 if (!strcmp (old_section_names + NEW_SECTION_H (nn).sh_name, ".data")
1264 || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name),
1265 ".sdata")
1266 || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name),
1267 ".lit4")
1268 || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name),
1269 ".lit8")
1270 #ifdef IRIX6_5 /* see above */
1271 || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name),
1272 ".got")
1273 #endif
1274 || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name),
1275 ".sdata1")
1276 || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name),
1277 ".data1"))
1279 ElfW (Addr) offset = (NEW_SECTION_H (nn).sh_addr
1280 - NEW_SECTION_H (nn).sh_offset);
1281 caddr_t reloc = old_base + section.sh_offset, end;
1282 for (end = reloc + section.sh_size; reloc < end;
1283 reloc += section.sh_entsize)
1285 ElfW (Addr) addr = ((ElfW (Rel) *) reloc)->r_offset - offset;
1286 #ifdef __alpha__
1287 /* The Alpha ELF binutils currently have a bug that
1288 sometimes results in relocs that contain all
1289 zeroes. Work around this for now... */
1290 if (((ElfW (Rel) *) reloc)->r_offset == 0)
1291 continue;
1292 #endif
1293 memcpy (new_base + addr, old_base + addr, sizeof (ElfW (Addr)));
1296 break;
1299 #undef n
1302 /* Write out new_file, and free the buffers. */
1304 if (write (new_file, new_base, new_file_size) != new_file_size)
1305 fatal ("Didn't write %lu bytes to %s: %s",
1306 (unsigned long) new_file_size, new_name, strerror (errno));
1307 munmap (old_base, old_file_size);
1308 munmap (new_base, new_file_size);
1310 /* Close the files and make the new file executable. */
1312 #if MAP_ANON == 0
1313 emacs_close (mmap_fd);
1314 #endif
1316 if (emacs_close (old_file) != 0)
1317 fatal ("Can't close (%s): %s", old_name, strerror (errno));
1319 if (emacs_close (new_file) != 0)
1320 fatal ("Can't close (%s): %s", new_name, strerror (errno));