1 /* Copyright (C) 1985, 1986, 1987, 1988, 1990, 1992, 1999, 2000, 2001,
2 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
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.
32 * Date: Tue Mar 2 1982
33 * Modified heavily since then.
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
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.
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
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
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
98 [2] 5 2 0x80480e8 0xe8 0x388 .hash
101 [3] 11 2 0x8048470 0x470 0x7f0 .dynsym
104 [4] 3 2 0x8048c60 0xc60 0x3ad .dynstr
107 [5] 9 2 0x8049010 0x1010 0x338 .rel.plt
110 [6] 1 6 0x8049348 0x1348 0x3 .init
113 [7] 1 6 0x804934c 0x134c 0x680 .plt
116 [8] 1 6 0x80499cc 0x19cc 0x3c56f .text
119 [9] 1 6 0x8085f3c 0x3df3c 0x3 .fini
122 [10] 1 2 0x8085f40 0x3df40 0x69c .rodata
125 [11] 1 2 0x80865dc 0x3e5dc 0xd51 .rodata1
128 [12] 1 3 0x8088330 0x3f330 0x20afc .data
131 [13] 1 3 0x80a8e2c 0x5fe2c 0x89d .data1
134 [14] 1 3 0x80a96cc 0x606cc 0x1a8 .got
137 [15] 6 3 0x80a9874 0x60874 0x80 .dynamic
140 [16] 8 3 0x80a98f4 0x608f4 0x449c .bss
143 [17] 2 0 0 0x608f4 0x9b90 .symtab
146 [18] 3 0 0 0x6a484 0x8526 .strtab
149 [19] 3 0 0 0x729aa 0x93 .shstrtab
152 [20] 1 0 0 0x72a3d 0x68b7 .comment
155 raid:/nfs/raid/src/dist-18.56/src> dump -h 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
166 [2] 5 2 0x80480e8 0xe8 0x388 .hash
169 [3] 11 2 0x8048470 0x470 0x7f0 .dynsym
172 [4] 3 2 0x8048c60 0xc60 0x3ad .dynstr
175 [5] 9 2 0x8049010 0x1010 0x338 .rel.plt
178 [6] 1 6 0x8049348 0x1348 0x3 .init
181 [7] 1 6 0x804934c 0x134c 0x680 .plt
184 [8] 1 6 0x80499cc 0x19cc 0x3c56f .text
187 [9] 1 6 0x8085f3c 0x3df3c 0x3 .fini
190 [10] 1 2 0x8085f40 0x3df40 0x69c .rodata
193 [11] 1 2 0x80865dc 0x3e5dc 0xd51 .rodata1
196 [12] 1 3 0x8088330 0x3f330 0x20afc .data
199 [13] 1 3 0x80a8e2c 0x5fe2c 0x89d .data1
202 [14] 1 3 0x80a96cc 0x606cc 0x1a8 .got
205 [15] 6 3 0x80a9874 0x60874 0x80 .dynamic
208 [16] 8 3 0x80c6800 0x7d800 0 .bss
211 [17] 2 0 0 0x7d800 0x9b90 .symtab
214 [18] 3 0 0 0x87390 0x8526 .strtab
217 [19] 3 0 0 0x8f8b6 0x93 .shstrtab
220 [20] 1 0 0 0x8f949 0x68b7 .comment
223 [21] 1 3 0x80a98f4 0x608f4 0x1cf0c .data
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
240 Class Data Type Machine Version
241 Entry Phoff Shoff Flags Ehsize
242 Phentsize Phnum Shentsz Shnum Shstrndx
245 0x80499cc 0x34 0x792f4 0 0x34
248 raid:/nfs/raid/src/dist-18.56/src> dump -f xemacs
253 Class Data Type Machine Version
254 Entry Phoff Shoff Flags Ehsize
255 Phentsize Phnum Shentsz Shnum Shstrndx
258 0x80499cc 0x34 0x96200 0 0x34
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
270 ***** PROGRAM EXECUTION HEADER *****
271 Type Offset Vaddr Paddr
272 Filesz Memsz Flags Align
281 0x3f2f9 0x3f2f9 5 0x1000
283 1 0x3f330 0x8088330 0
284 0x215c4 0x25a60 7 0x1000
286 2 0x60874 0x80a9874 0
289 raid:/nfs/raid/src/dist-18.56/src> dump -o xemacs
292 ***** PROGRAM EXECUTION HEADER *****
293 Type Offset Vaddr Paddr
294 Filesz Memsz Flags Align
303 0x3f2f9 0x3f2f9 5 0x1000
305 1 0x3f330 0x8088330 0
306 0x3e4d0 0x3e4d0 7 0x1000
308 2 0x60874 0x80a9874 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
345 [2] 5 2 0x80480e8 0xe8 0x388 .hash
348 [3] 11 2 0x8048470 0x470 0x7f0 .dynsym
351 [4] 3 2 0x8048c60 0xc60 0x3ad .dynstr
354 [5] 9 2 0x8049010 0x1010 0x338 .rel.plt
357 [6] 1 6 0x8049348 0x1348 0x3 .init
360 [7] 1 6 0x804934c 0x134c 0x680 .plt
363 [8] 1 6 0x80499cc 0x19cc 0x3c56f .text
366 [9] 1 6 0x8085f3c 0x3df3c 0x3 .fini
369 [10] 1 2 0x8085f40 0x3df40 0x69c .rodata
372 [11] 1 2 0x80865dc 0x3e5dc 0xd51 .rodata1
375 [12] 1 3 0x8088330 0x3f330 0x20afc .data
378 [13] 1 3 0x80a8e2c 0x5fe2c 0x89d .data1
381 [14] 1 3 0x80a96cc 0x606cc 0x1a8 .got
384 [15] 6 3 0x80a9874 0x60874 0x80 .dynamic
387 [16] 1 3 0x80a98f4 0x608f4 0x1cf0c .data
390 [17] 8 3 0x80c6800 0x7d800 0 .bss
393 [18] 2 0 0 0x7d800 0x9b90 .symtab
396 [19] 3 0 0 0x87390 0x8526 .strtab
399 [20] 3 0 0 0x8f8b6 0x93 .shstrtab
402 [21] 1 0 0 0x8f949 0x68b7 .comment
407 /* We do not use mmap because that fails with NFS.
408 Instead we read the whole file, modify it, and write it out. */
411 #define fatal(a, b, c) fprintf (stderr, a, b, c), exit (1)
415 extern void fatal (const char *msgid
, ...);
418 #include <sys/types.h>
420 #include <sys/stat.h>
425 #if !defined (__NetBSD__) && !defined (__OpenBSD__)
428 #include <sys/mman.h>
429 #if defined (_SYSTYPE_SYSV)
430 #include <sys/elf_mips.h>
432 #endif /* _SYSTYPE_SYSV */
434 #include <syms.h> /* for HDRR declaration */
439 #define MAP_ANON MAP_ANONYMOUS
446 #define MAP_FAILED ((void *) -1)
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. */
480 #define cbHDRR sizeof(HDRR)
481 #define hdrNil ((pHDRR)0)
486 * NetBSD does not have normal-looking user-land ELF support.
488 # if defined __alpha__ || defined __sparc_v9__
493 # include <sys/exec_elf.h>
496 # define PT_LOAD Elf_pt_load
497 # if 0 /* was in pkgsrc patches for 20.7 */
498 # define SHT_PROGBITS Elf_sht_progbits
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 */
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__ */
525 # include <sys/exec_elf.h>
528 #if __GNU_LIBRARY__ - 0 >= 6
529 # include <link.h> /* get ElfW etc */
534 # define ElfBitsW(bits, type) Elf##bits##_##type
536 # define ElfBitsW(bits, type) Elf/**/bits/**/_/**/type
543 /* This macro expands `bits' before invoking ElfBitsW. */
544 # define ElfExpandBitsW(bits, type) ElfBitsW (bits, type)
545 # define ElfW(type) ElfExpandBitsW (ELFSIZE, type)
548 #ifndef ELF_BSS_SECTION_NAME
549 #define ELF_BSS_SECTION_NAME ".bss"
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
571 The changed code is minimal and depends on prep set in m/prep.h
573 Quantum Theory Project
574 University of Florida
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) \
590 if ((int) (n) >= old_bss_index) \
592 typedef unsigned char byte
;
594 /* Round X up to a multiple of 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. */
614 find_section (name
, section_names
, file_name
, old_file_h
, old_section_h
, noerror
)
618 ElfW(Ehdr
) *old_file_h
;
619 ElfW(Shdr
) *old_section_h
;
624 for (idx
= 1; idx
< old_file_h
->e_shnum
; idx
++)
627 fprintf (stderr
, "Looking for %s - found %s\n", name
,
628 section_names
+ OLD_SECTION_H (idx
).sh_name
);
630 if (!strcmp (section_names
+ OLD_SECTION_H (idx
).sh_name
,
634 if (idx
== old_file_h
->e_shnum
)
639 fatal ("Can't find %s in %s.\n", name
, file_name
);
645 /* ****************************************************************
650 * In ELF, this works by replacing the old .bss section with a new
651 * .data section, and inserting an empty .bss immediately afterwards.
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
;
670 /* Pointers to the file, program and section headers for the old and
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
;
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
;
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
);
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
);
705 mmap_fd
= open ("/dev/zero", O_RDONLY
);
707 fatal ("Can't open /dev/zero for reading: errno %d\n", errno
, 0);
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
)
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
)
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
;
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);
793 new_bss_addr
= old_bss_addr
+ old_bss_size
+ 0x1234;
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
);
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
);
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);
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
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
856 new_file_h
->e_shoff
+= new_data2_incr
;
857 new_file_h
->e_shnum
+= 1;
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
);
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
;
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)
887 if (NEW_PROGRAM_H (n
).p_vaddr
+ NEW_PROGRAM_H (n
).p_filesz
888 > (old_sbss_index
== -1
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
,
897 == round_up (old_bss_addr
, alignment
)))
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
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
;
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. */
925 for (old_data_index
= 1; old_data_index
< (int) old_file_h
->e_shnum
;
927 if (!strcmp (old_section_names
+ OLD_SECTION_H (old_data_index
).sh_name
,
930 if (old_data_index
== old_file_h
->e_shnum
)
931 fatal ("Can't find .data in %s.\n", old_name
, 0);
933 /* Walk through all section headers, insert the new data2 section right
934 before the new bss section. */
935 for (n
= 1, nn
= 1; n
< (int) old_file_h
->e_shnum
; n
++, nn
++)
938 /* If it is (s)bss section, insert the new data2 section before it. */
939 /* new_data2_index is the index of either old_sbss or old_bss, that was
940 chosen as a section for new_data2. */
941 if (n
== new_data2_index
)
943 /* Steal the data section header for this data2 section. */
944 memcpy (&NEW_SECTION_H (nn
), &OLD_SECTION_H (old_data_index
),
945 new_file_h
->e_shentsize
);
947 NEW_SECTION_H (nn
).sh_addr
= new_data2_addr
;
948 NEW_SECTION_H (nn
).sh_offset
= new_data2_offset
;
949 NEW_SECTION_H (nn
).sh_size
= new_data2_size
;
950 /* Use the bss section's alignment. This will assure that the
951 new data2 section always be placed in the same spot as the old
952 bss section by any other application. */
953 NEW_SECTION_H (nn
).sh_addralign
= OLD_SECTION_H (n
).sh_addralign
;
955 /* Now copy over what we have in the memory now. */
956 memcpy (NEW_SECTION_H (nn
).sh_offset
+ new_base
,
957 (caddr_t
) OLD_SECTION_H (n
).sh_addr
,
962 memcpy (&NEW_SECTION_H (nn
), &OLD_SECTION_H (n
),
963 old_file_h
->e_shentsize
);
965 if (n
== old_bss_index
966 /* The new bss and sbss section's size is zero, and its file offset
967 and virtual address should be off by NEW_DATA2_SIZE. */
968 || n
== old_sbss_index
|| n
== old_plt_index
971 /* NN should be `old_s?bss_index + 1' at this point. */
972 NEW_SECTION_H (nn
).sh_offset
= new_data2_offset
+ new_data2_size
;
973 NEW_SECTION_H (nn
).sh_addr
= new_data2_addr
+ new_data2_size
;
974 /* Let the new bss section address alignment be the same as the
975 section address alignment followed the old bss section, so
976 this section will be placed in exactly the same place. */
977 NEW_SECTION_H (nn
).sh_addralign
= OLD_SECTION_H (nn
).sh_addralign
;
978 NEW_SECTION_H (nn
).sh_size
= 0;
982 /* Any section that was originally placed after the .bss
983 section should now be off by NEW_DATA2_INCR. If a
984 section overlaps the .bss section, consider it to be
985 placed after the .bss section. Overlap can occur if the
986 section just before .bss has less-strict alignment; this
987 was observed between .symtab and .bss on Solaris 2.5.1
988 (sparc) with GCC snapshot 960602. */
990 if (NEW_SECTION_H (nn
).sh_offset
>= old_bss_offset
)
991 NEW_SECTION_H (nn
).sh_offset
+= new_data2_incr
;
993 /* Any section that was originally placed after the section
994 header table should now be off by the size of one section
995 header table entry. */
996 if (NEW_SECTION_H (nn
).sh_offset
> new_file_h
->e_shoff
)
997 NEW_SECTION_H (nn
).sh_offset
+= new_file_h
->e_shentsize
;
1000 /* If any section hdr refers to the section after the new .data
1001 section, make it refer to next one because we have inserted
1002 a new section in between. */
1004 PATCH_INDEX (NEW_SECTION_H (nn
).sh_link
);
1005 /* For symbol tables, info is a symbol table index,
1006 so don't change it. */
1007 if (NEW_SECTION_H (nn
).sh_type
!= SHT_SYMTAB
1008 && NEW_SECTION_H (nn
).sh_type
!= SHT_DYNSYM
)
1009 PATCH_INDEX (NEW_SECTION_H (nn
).sh_info
);
1011 if (old_sbss_index
!= -1)
1012 if (!strcmp (old_section_names
+ NEW_SECTION_H (nn
).sh_name
, ".sbss"))
1014 NEW_SECTION_H (nn
).sh_offset
=
1015 round_up (NEW_SECTION_H (nn
).sh_offset
,
1016 NEW_SECTION_H (nn
).sh_addralign
);
1017 NEW_SECTION_H (nn
).sh_type
= SHT_PROGBITS
;
1020 /* Now, start to copy the content of sections. */
1021 if (NEW_SECTION_H (nn
).sh_type
== SHT_NULL
1022 || NEW_SECTION_H (nn
).sh_type
== SHT_NOBITS
)
1025 /* Write out the sections. .data and .data1 (and data2, called
1026 ".data" in the strings table) get copied from the current process
1027 instead of the old file. */
1028 if (!strcmp (old_section_names
+ NEW_SECTION_H (n
).sh_name
, ".data")
1029 || !strcmp ((old_section_names
+ NEW_SECTION_H (n
).sh_name
),
1031 || !strcmp ((old_section_names
+ NEW_SECTION_H (n
).sh_name
),
1033 || !strcmp ((old_section_names
+ NEW_SECTION_H (n
).sh_name
),
1035 /* The conditional bit below was in Oliva's original code
1036 (1999-08-25) and seems to have been dropped by mistake
1037 subsequently. It prevents a crash at startup under X in
1038 `IRIX64 6.5 6.5.17m', whether compiled on that relase or
1039 an earlier one. It causes no trouble on the other ELF
1040 platforms I could test (Irix 6.5.15m, Solaris 8, Debian
1041 Potato x86, Debian Woody SPARC); however, it's reported
1042 to cause crashes under some version of GNU/Linux. It's
1043 not yet clear what's changed in that Irix version to
1044 cause the problem, or why the fix sometimes fails under
1045 GNU/Linux. There's probably no good reason to have
1046 something Irix-specific here, but this will have to do
1047 for now. IRIX6_5 is the most specific macro we have to
1048 test. -- fx 2002-10-01
1050 The issue _looks_ as though it's gone away on 6.5.18m,
1051 but maybe it's still lurking, to be triggered by some
1052 change in the binary. It appears to concern the dynamic
1053 loader, but I never got anywhere with an SGI support call
1054 seeking clues. -- fx 2002-11-29. */
1056 || !strcmp ((old_section_names
+ NEW_SECTION_H (n
).sh_name
),
1059 || !strcmp ((old_section_names
+ NEW_SECTION_H (n
).sh_name
),
1061 || !strcmp ((old_section_names
+ NEW_SECTION_H (n
).sh_name
),
1063 || !strcmp ((old_section_names
+ NEW_SECTION_H (n
).sh_name
),
1065 src
= (caddr_t
) OLD_SECTION_H (n
).sh_addr
;
1067 src
= old_base
+ OLD_SECTION_H (n
).sh_offset
;
1069 memcpy (NEW_SECTION_H (nn
).sh_offset
+ new_base
, src
,
1070 NEW_SECTION_H (nn
).sh_size
);
1073 /* Update Alpha COFF symbol table: */
1074 if (strcmp (old_section_names
+ OLD_SECTION_H (n
).sh_name
, ".mdebug")
1077 pHDRR symhdr
= (pHDRR
) (NEW_SECTION_H (nn
).sh_offset
+ new_base
);
1079 symhdr
->cbLineOffset
+= new_data2_size
;
1080 symhdr
->cbDnOffset
+= new_data2_size
;
1081 symhdr
->cbPdOffset
+= new_data2_size
;
1082 symhdr
->cbSymOffset
+= new_data2_size
;
1083 symhdr
->cbOptOffset
+= new_data2_size
;
1084 symhdr
->cbAuxOffset
+= new_data2_size
;
1085 symhdr
->cbSsOffset
+= new_data2_size
;
1086 symhdr
->cbSsExtOffset
+= new_data2_size
;
1087 symhdr
->cbFdOffset
+= new_data2_size
;
1088 symhdr
->cbRfdOffset
+= new_data2_size
;
1089 symhdr
->cbExtOffset
+= new_data2_size
;
1091 #endif /* __alpha__ */
1093 #if defined (_SYSTYPE_SYSV)
1094 if (NEW_SECTION_H (nn
).sh_type
== SHT_MIPS_DEBUG
1095 && old_mdebug_index
!= -1)
1097 int diff
= NEW_SECTION_H(nn
).sh_offset
1098 - OLD_SECTION_H(old_mdebug_index
).sh_offset
;
1099 HDRR
*phdr
= (HDRR
*)(NEW_SECTION_H (nn
).sh_offset
+ new_base
);
1103 phdr
->cbLineOffset
+= diff
;
1104 phdr
->cbDnOffset
+= diff
;
1105 phdr
->cbPdOffset
+= diff
;
1106 phdr
->cbSymOffset
+= diff
;
1107 phdr
->cbOptOffset
+= diff
;
1108 phdr
->cbAuxOffset
+= diff
;
1109 phdr
->cbSsOffset
+= diff
;
1110 phdr
->cbSsExtOffset
+= diff
;
1111 phdr
->cbFdOffset
+= diff
;
1112 phdr
->cbRfdOffset
+= diff
;
1113 phdr
->cbExtOffset
+= diff
;
1116 #endif /* _SYSTYPE_SYSV */
1119 /* Adjust the HDRR offsets in .mdebug and copy the
1120 line data if it's in its usual 'hole' in the object.
1121 Makes the new file debuggable with dbx.
1122 patches up two problems: the absolute file offsets
1123 in the HDRR record of .mdebug (see /usr/include/syms.h), and
1124 the ld bug that gets the line table in a hole in the
1125 elf file rather than in the .mdebug section proper.
1126 David Anderson. davea@sgi.com Jan 16,1994. */
1127 if (n
== old_mdebug_index
)
1129 #define MDEBUGADJUST(__ct,__fileaddr) \
1130 if (n_phdrr->__ct > 0) \
1132 n_phdrr->__fileaddr += movement; \
1135 HDRR
* o_phdrr
= (HDRR
*)((byte
*)old_base
+ OLD_SECTION_H (n
).sh_offset
);
1136 HDRR
* n_phdrr
= (HDRR
*)((byte
*)new_base
+ NEW_SECTION_H (nn
).sh_offset
);
1137 unsigned movement
= new_data2_size
;
1139 MDEBUGADJUST (idnMax
, cbDnOffset
);
1140 MDEBUGADJUST (ipdMax
, cbPdOffset
);
1141 MDEBUGADJUST (isymMax
, cbSymOffset
);
1142 MDEBUGADJUST (ioptMax
, cbOptOffset
);
1143 MDEBUGADJUST (iauxMax
, cbAuxOffset
);
1144 MDEBUGADJUST (issMax
, cbSsOffset
);
1145 MDEBUGADJUST (issExtMax
, cbSsExtOffset
);
1146 MDEBUGADJUST (ifdMax
, cbFdOffset
);
1147 MDEBUGADJUST (crfd
, cbRfdOffset
);
1148 MDEBUGADJUST (iextMax
, cbExtOffset
);
1149 /* The Line Section, being possible off in a hole of the object,
1150 requires special handling. */
1151 if (n_phdrr
->cbLine
> 0)
1153 if (o_phdrr
->cbLineOffset
> (OLD_SECTION_H (n
).sh_offset
1154 + OLD_SECTION_H (n
).sh_size
))
1156 /* line data is in a hole in elf. do special copy and adjust
1157 for this ld mistake.
1159 n_phdrr
->cbLineOffset
+= movement
;
1161 memcpy (n_phdrr
->cbLineOffset
+ new_base
,
1162 o_phdrr
->cbLineOffset
+ old_base
, n_phdrr
->cbLine
);
1166 /* somehow line data is in .mdebug as it is supposed to be. */
1167 MDEBUGADJUST (cbLine
, cbLineOffset
);
1173 /* If it is the symbol table, its st_shndx field needs to be patched. */
1174 if (NEW_SECTION_H (nn
).sh_type
== SHT_SYMTAB
1175 || NEW_SECTION_H (nn
).sh_type
== SHT_DYNSYM
)
1177 ElfW(Shdr
) *spt
= &NEW_SECTION_H (nn
);
1178 unsigned int num
= spt
->sh_size
/ spt
->sh_entsize
;
1179 ElfW(Sym
) * sym
= (ElfW(Sym
) *) (NEW_SECTION_H (nn
).sh_offset
+
1181 for (; num
--; sym
++)
1183 if ((sym
->st_shndx
== SHN_UNDEF
)
1184 || (sym
->st_shndx
== SHN_ABS
)
1185 || (sym
->st_shndx
== SHN_COMMON
))
1188 PATCH_INDEX (sym
->st_shndx
);
1193 /* Update the symbol values of _edata and _end. */
1194 for (n
= new_file_h
->e_shnum
- 1; n
; n
--)
1197 ElfW(Sym
) *symp
, *symendp
;
1199 if (NEW_SECTION_H (n
).sh_type
!= SHT_DYNSYM
1200 && NEW_SECTION_H (n
).sh_type
!= SHT_SYMTAB
)
1203 symnames
= ((byte
*) new_base
1204 + NEW_SECTION_H (NEW_SECTION_H (n
).sh_link
).sh_offset
);
1205 symp
= (ElfW(Sym
) *) (NEW_SECTION_H (n
).sh_offset
+ new_base
);
1206 symendp
= (ElfW(Sym
) *) ((byte
*)symp
+ NEW_SECTION_H (n
).sh_size
);
1208 for (; symp
< symendp
; symp
++)
1209 if (strcmp ((char *) (symnames
+ symp
->st_name
), "_end") == 0
1210 || strcmp ((char *) (symnames
+ symp
->st_name
), "end") == 0
1211 || strcmp ((char *) (symnames
+ symp
->st_name
), "_edata") == 0
1212 || strcmp ((char *) (symnames
+ symp
->st_name
), "edata") == 0)
1213 memcpy (&symp
->st_value
, &new_bss_addr
, sizeof (new_bss_addr
));
1216 /* This loop seeks out relocation sections for the data section, so
1217 that it can undo relocations performed by the runtime linker. */
1218 for (n
= new_file_h
->e_shnum
- 1; n
; n
--)
1220 ElfW(Shdr
) section
= NEW_SECTION_H (n
);
1222 /* Cause a compilation error if anyone uses n instead of nn below. */
1224 (void)n
.a
; /* Prevent `unused variable' warnings. */
1226 switch (section
.sh_type
)
1232 /* This code handles two different size structs, but there should
1233 be no harm in that provided that r_offset is always the first
1235 nn
= section
.sh_info
;
1236 if (!strcmp (old_section_names
+ NEW_SECTION_H (nn
).sh_name
, ".data")
1237 || !strcmp ((old_section_names
+ NEW_SECTION_H (nn
).sh_name
),
1239 || !strcmp ((old_section_names
+ NEW_SECTION_H (nn
).sh_name
),
1241 || !strcmp ((old_section_names
+ NEW_SECTION_H (nn
).sh_name
),
1243 #ifdef IRIX6_5 /* see above */
1244 || !strcmp ((old_section_names
+ NEW_SECTION_H (nn
).sh_name
),
1247 || !strcmp ((old_section_names
+ NEW_SECTION_H (nn
).sh_name
),
1249 || !strcmp ((old_section_names
+ NEW_SECTION_H (nn
).sh_name
),
1252 ElfW(Addr
) offset
= (NEW_SECTION_H (nn
).sh_addr
1253 - NEW_SECTION_H (nn
).sh_offset
);
1254 caddr_t reloc
= old_base
+ section
.sh_offset
, end
;
1255 for (end
= reloc
+ section
.sh_size
; reloc
< end
;
1256 reloc
+= section
.sh_entsize
)
1258 ElfW(Addr
) addr
= ((ElfW(Rel
) *) reloc
)->r_offset
- offset
;
1260 /* The Alpha ELF binutils currently have a bug that
1261 sometimes results in relocs that contain all
1262 zeroes. Work around this for now... */
1263 if (((ElfW(Rel
) *) reloc
)->r_offset
== 0)
1266 memcpy (new_base
+ addr
, old_base
+ addr
, sizeof(ElfW(Addr
)));
1273 /* Write out new_file, and free the buffers. */
1275 if (write (new_file
, new_base
, new_file_size
) != new_file_size
)
1277 fatal ("Didn't write %d bytes: errno %d\n",
1278 new_file_size
, errno
);
1280 fatal ("Didn't write %d bytes to %s: errno %d\n",
1281 new_file_size
, new_base
, errno
);
1283 munmap (old_base
, old_file_size
);
1284 munmap (new_base
, new_file_size
);
1286 /* Close the files and make the new file executable. */
1292 if (close (old_file
))
1293 fatal ("Can't close (%s): errno %d\n", old_name
, errno
);
1295 if (close (new_file
))
1296 fatal ("Can't close (%s): errno %d\n", new_name
, errno
);
1298 if (stat (new_name
, &stat_buf
) == -1)
1299 fatal ("Can't stat (%s): errno %d\n", new_name
, errno
);
1303 stat_buf
.st_mode
|= 0111 & ~n
;
1304 if (chmod (new_name
, stat_buf
.st_mode
) == -1)
1305 fatal ("Can't chmod (%s): errno %d\n", new_name
, errno
);
1308 /* arch-tag: e02e1512-95e2-4ef0-bba7-b6bce658f1e3
1309 (do not change this comment) */