1 /* Copyright (C) 1985, 1986, 1987, 1988, 1990, 1992
2 Free Software 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 2, or (at your option)
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; see the file COPYING. If not, write to
18 the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA.
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 * Specifying zero for data_start means the boundary between text and data
56 * should not be the same as when the program was loaded.
57 * If NO_REMAP is defined, the argument data_start is ignored and the
58 * segment boundaries are never changed.
60 * Bss_start indicates how much of the data segment is to be saved in the
61 * a.out file and restored when the program is executed. It gives the lowest
62 * unsaved address, and is rounded up to a page boundary. The default when 0
63 * is given assumes that the entire data segment is to be stored, including
64 * the previous data and bss as well as any additional storage allocated with
67 * The new file is set up to start at entry_address.
69 * If you make improvements I'd like to get them too.
70 * harpo!utah-cs!thomas, thomas@Utah-20
74 /* Even more heavily modified by james@bigtex.cactus.org of Dell Computer Co.
77 * Basic theory: the data space of the running process needs to be
78 * dumped to the output file. Normally we would just enlarge the size
79 * of .data, scooting everything down. But we can't do that in ELF,
80 * because there is often something between the .data space and the
83 * In the temacs dump below, notice that the Global Offset Table
84 * (.got) and the Dynamic link data (.dynamic) come between .data1 and
85 * .bss. It does not work to overlap .data with these fields.
87 * The solution is to create a new .data segment. This segment is
88 * filled with data from the current process. Since the contents of
89 * various sections refer to sections by index, the new .data segment
90 * is made the last in the table to avoid changing any existing index.
92 * This is an example of how the section headers are changed. "Addr"
93 * is a process virtual address. "Offset" is a file offset.
95 raid:/nfs/raid/src/dist-18.56/src> dump -h temacs
99 **** SECTION HEADER TABLE ****
100 [No] Type Flags Addr Offset Size Name
101 Link Info Adralgn Entsize
103 [1] 1 2 0x80480d4 0xd4 0x13 .interp
106 [2] 5 2 0x80480e8 0xe8 0x388 .hash
109 [3] 11 2 0x8048470 0x470 0x7f0 .dynsym
112 [4] 3 2 0x8048c60 0xc60 0x3ad .dynstr
115 [5] 9 2 0x8049010 0x1010 0x338 .rel.plt
118 [6] 1 6 0x8049348 0x1348 0x3 .init
121 [7] 1 6 0x804934c 0x134c 0x680 .plt
124 [8] 1 6 0x80499cc 0x19cc 0x3c56f .text
127 [9] 1 6 0x8085f3c 0x3df3c 0x3 .fini
130 [10] 1 2 0x8085f40 0x3df40 0x69c .rodata
133 [11] 1 2 0x80865dc 0x3e5dc 0xd51 .rodata1
136 [12] 1 3 0x8088330 0x3f330 0x20afc .data
139 [13] 1 3 0x80a8e2c 0x5fe2c 0x89d .data1
142 [14] 1 3 0x80a96cc 0x606cc 0x1a8 .got
145 [15] 6 3 0x80a9874 0x60874 0x80 .dynamic
148 [16] 8 3 0x80a98f4 0x608f4 0x449c .bss
151 [17] 2 0 0 0x608f4 0x9b90 .symtab
154 [18] 3 0 0 0x6a484 0x8526 .strtab
157 [19] 3 0 0 0x729aa 0x93 .shstrtab
160 [20] 1 0 0 0x72a3d 0x68b7 .comment
163 raid:/nfs/raid/src/dist-18.56/src> dump -h xemacs
167 **** SECTION HEADER TABLE ****
168 [No] Type Flags Addr Offset Size Name
169 Link Info Adralgn Entsize
171 [1] 1 2 0x80480d4 0xd4 0x13 .interp
174 [2] 5 2 0x80480e8 0xe8 0x388 .hash
177 [3] 11 2 0x8048470 0x470 0x7f0 .dynsym
180 [4] 3 2 0x8048c60 0xc60 0x3ad .dynstr
183 [5] 9 2 0x8049010 0x1010 0x338 .rel.plt
186 [6] 1 6 0x8049348 0x1348 0x3 .init
189 [7] 1 6 0x804934c 0x134c 0x680 .plt
192 [8] 1 6 0x80499cc 0x19cc 0x3c56f .text
195 [9] 1 6 0x8085f3c 0x3df3c 0x3 .fini
198 [10] 1 2 0x8085f40 0x3df40 0x69c .rodata
201 [11] 1 2 0x80865dc 0x3e5dc 0xd51 .rodata1
204 [12] 1 3 0x8088330 0x3f330 0x20afc .data
207 [13] 1 3 0x80a8e2c 0x5fe2c 0x89d .data1
210 [14] 1 3 0x80a96cc 0x606cc 0x1a8 .got
213 [15] 6 3 0x80a9874 0x60874 0x80 .dynamic
216 [16] 8 3 0x80c6800 0x7d800 0 .bss
219 [17] 2 0 0 0x7d800 0x9b90 .symtab
222 [18] 3 0 0 0x87390 0x8526 .strtab
225 [19] 3 0 0 0x8f8b6 0x93 .shstrtab
228 [20] 1 0 0 0x8f949 0x68b7 .comment
231 [21] 1 3 0x80a98f4 0x608f4 0x1cf0c .data
234 * This is an example of how the file header is changed. "Shoff" is
235 * the section header offset within the file. Since that table is
236 * after the new .data section, it is moved. "Shnum" is the number of
237 * sections, which we increment.
239 * "Phoff" is the file offset to the program header. "Phentsize" and
240 * "Shentsz" are the program and section header entries sizes respectively.
241 * These can be larger than the apparent struct sizes.
243 raid:/nfs/raid/src/dist-18.56/src> dump -f temacs
248 Class Data Type Machine Version
249 Entry Phoff Shoff Flags Ehsize
250 Phentsize Phnum Shentsz Shnum Shstrndx
253 0x80499cc 0x34 0x792f4 0 0x34
256 raid:/nfs/raid/src/dist-18.56/src> dump -f xemacs
261 Class Data Type Machine Version
262 Entry Phoff Shoff Flags Ehsize
263 Phentsize Phnum Shentsz Shnum Shstrndx
266 0x80499cc 0x34 0x96200 0 0x34
269 * These are the program headers. "Offset" is the file offset to the
270 * segment. "Vaddr" is the memory load address. "Filesz" is the
271 * segment size as it appears in the file, and "Memsz" is the size in
272 * memory. Below, the third segment is the code and the fourth is the
273 * data: the difference between Filesz and Memsz is .bss
275 raid:/nfs/raid/src/dist-18.56/src> dump -o temacs
278 ***** PROGRAM EXECUTION HEADER *****
279 Type Offset Vaddr Paddr
280 Filesz Memsz Flags Align
289 0x3f2f9 0x3f2f9 5 0x1000
291 1 0x3f330 0x8088330 0
292 0x215c4 0x25a60 7 0x1000
294 2 0x60874 0x80a9874 0
297 raid:/nfs/raid/src/dist-18.56/src> dump -o xemacs
300 ***** PROGRAM EXECUTION HEADER *****
301 Type Offset Vaddr Paddr
302 Filesz Memsz Flags Align
311 0x3f2f9 0x3f2f9 5 0x1000
313 1 0x3f330 0x8088330 0
314 0x3e4d0 0x3e4d0 7 0x1000
316 2 0x60874 0x80a9874 0
322 /* Modified by wtien@urbana.mcd.mot.com of Motorola Inc.
324 * The above mechanism does not work if the unexeced ELF file is being
325 * re-layout by other applications (such as `strip'). All the applications
326 * that re-layout the internal of ELF will layout all sections in ascending
327 * order of their file offsets. After the re-layout, the data2 section will
328 * still be the LAST section in the section header vector, but its file offset
329 * is now being pushed far away down, and causes part of it not to be mapped
330 * in (ie. not covered by the load segment entry in PHDR vector), therefore
331 * causes the new binary to fail.
333 * The solution is to modify the unexec algorithm to insert the new data2
334 * section header right before the new bss section header, so their file
335 * offsets will be in the ascending order. Since some of the section's (all
336 * sections AFTER the bss section) indexes are now changed, we also need to
337 * modify some fields to make them point to the right sections. This is done
338 * by macro PATCH_INDEX. All the fields that need to be patched are:
340 * 1. ELF header e_shstrndx field.
341 * 2. section header sh_link and sh_info field.
342 * 3. symbol table entry st_shndx field.
344 * The above example now should look like:
346 **** SECTION HEADER TABLE ****
347 [No] Type Flags Addr Offset Size Name
348 Link Info Adralgn Entsize
350 [1] 1 2 0x80480d4 0xd4 0x13 .interp
353 [2] 5 2 0x80480e8 0xe8 0x388 .hash
356 [3] 11 2 0x8048470 0x470 0x7f0 .dynsym
359 [4] 3 2 0x8048c60 0xc60 0x3ad .dynstr
362 [5] 9 2 0x8049010 0x1010 0x338 .rel.plt
365 [6] 1 6 0x8049348 0x1348 0x3 .init
368 [7] 1 6 0x804934c 0x134c 0x680 .plt
371 [8] 1 6 0x80499cc 0x19cc 0x3c56f .text
374 [9] 1 6 0x8085f3c 0x3df3c 0x3 .fini
377 [10] 1 2 0x8085f40 0x3df40 0x69c .rodata
380 [11] 1 2 0x80865dc 0x3e5dc 0xd51 .rodata1
383 [12] 1 3 0x8088330 0x3f330 0x20afc .data
386 [13] 1 3 0x80a8e2c 0x5fe2c 0x89d .data1
389 [14] 1 3 0x80a96cc 0x606cc 0x1a8 .got
392 [15] 6 3 0x80a9874 0x60874 0x80 .dynamic
395 [16] 1 3 0x80a98f4 0x608f4 0x1cf0c .data
398 [17] 8 3 0x80c6800 0x7d800 0 .bss
401 [18] 2 0 0 0x7d800 0x9b90 .symtab
404 [19] 3 0 0 0x87390 0x8526 .strtab
407 [20] 3 0 0 0x8f8b6 0x93 .shstrtab
410 [21] 1 0 0 0x8f949 0x68b7 .comment
415 #include <sys/types.h>
417 #include <sys/stat.h>
423 #if !defined (__NetBSD__) && !defined (__OpenBSD__)
426 #include <sys/mman.h>
427 #if defined (__sony_news) && defined (_SYSTYPE_SYSV)
428 #include <sys/elf_mips.h>
430 #endif /* __sony_news && _SYSTYPE_SYSV */
432 #include <sym.h> /* for HDRR declaration */
435 #if defined (__alpha__) && !defined (__NetBSD__) && !defined (__OpenBSD__)
436 /* Declare COFF debugging symbol table. This used to be in
437 /usr/include/sym.h, but this file is no longer included in Red Hat
438 5.0 and presumably in any other glibc 2.x based distribution. */
466 #define cbHDRR sizeof(HDRR)
467 #define hdrNil ((pHDRR)0)
472 * NetBSD does not have normal-looking user-land ELF support.
479 # include <sys/exec_elf.h>
481 # define PT_LOAD Elf_pt_load
482 # define SHT_SYMTAB Elf_sht_symtab
483 # define SHT_DYNSYM Elf_sht_dynsym
484 # define SHT_NULL Elf_sht_null
485 # define SHT_NOBITS Elf_sht_nobits
486 # define SHT_REL Elf_sht_rel
487 # define SHT_RELA Elf_sht_rela
489 # define SHN_UNDEF Elf_eshn_undefined
490 # define SHN_ABS Elf_eshn_absolute
491 # define SHN_COMMON Elf_eshn_common
494 * The magic of picking the right size types is handled by the ELFSIZE
498 # define ElfW(type) Elf_##type
500 # define ElfW(type) Elf_/**/type
504 # include <sys/exec_ecoff.h>
505 # define HDRR struct ecoff_symhdr
506 # define pHDRR HDRR *
508 #endif /* __NetBSD__ */
511 # include <sys/exec_elf.h>
514 #if __GNU_LIBRARY__ - 0 >= 6
515 # include <link.h> /* get ElfW etc */
520 # define ElfW(type) Elf32_##type
522 # define ElfW(type) Elf32_/**/type
527 #define fatal(a, b, c) fprintf (stderr, a, b, c), exit (1)
530 extern void fatal (char *, ...);
533 #ifndef ELF_BSS_SECTION_NAME
534 #define ELF_BSS_SECTION_NAME ".bss"
537 /* Get the address of a particular section or program header entry,
538 * accounting for the size of the entries.
541 On PPC Reference Platform running Solaris 2.5.1
542 the plt section is also of type NOBI like the bss section.
543 (not really stored) and therefore sections after the bss
544 section start at the plt offset. The plt section is always
545 the one just before the bss section.
546 Thus, we modify the test from
547 if (NEW_SECTION_H (nn).sh_offset >= new_data2_offset)
549 if (NEW_SECTION_H (nn).sh_offset >=
550 OLD_SECTION_H (old_bss_index-1).sh_offset)
551 This is just a hack. We should put the new data section
552 before the .plt section.
553 And we should not have this routine at all but use
554 the libelf library to read the old file and create the new
556 The changed code is minimal and depends on prep set in m/prep.h
558 Quantum Theory Project
559 University of Florida
564 #define OLD_SECTION_H(n) \
565 (*(ElfW(Shdr) *) ((byte *) old_section_h + old_file_h->e_shentsize * (n)))
566 #define NEW_SECTION_H(n) \
567 (*(ElfW(Shdr) *) ((byte *) new_section_h + new_file_h->e_shentsize * (n)))
568 #define OLD_PROGRAM_H(n) \
569 (*(ElfW(Phdr) *) ((byte *) old_program_h + old_file_h->e_phentsize * (n)))
570 #define NEW_PROGRAM_H(n) \
571 (*(ElfW(Phdr) *) ((byte *) new_program_h + new_file_h->e_phentsize * (n)))
573 #define PATCH_INDEX(n) \
575 if ((int) (n) >= old_bss_index) \
577 typedef unsigned char byte
;
579 /* Round X up to a multiple of Y. */
591 /* ****************************************************************
596 * In ELF, this works by replacing the old .bss section with a new
597 * .data section, and inserting an empty .bss immediately afterwards.
601 unexec (new_name
, old_name
, data_start
, bss_start
, entry_address
)
602 char *new_name
, *old_name
;
603 unsigned data_start
, bss_start
, entry_address
;
605 int new_file
, old_file
, new_file_size
;
607 /* Pointers to the base of the image of the two files. */
608 caddr_t old_base
, new_base
;
610 /* Pointers to the file, program and section headers for the old and new
613 ElfW(Ehdr
) *old_file_h
, *new_file_h
;
614 ElfW(Phdr
) *old_program_h
, *new_program_h
;
615 ElfW(Shdr
) *old_section_h
, *new_section_h
;
617 /* Point to the section name table in the old file */
618 char *old_section_names
;
620 ElfW(Addr
) old_bss_addr
, new_bss_addr
;
621 ElfW(Word
) old_bss_size
, new_data2_size
;
622 ElfW(Off
) new_data2_offset
;
623 ElfW(Addr
) new_data2_addr
;
625 int n
, nn
, old_bss_index
, old_data_index
, new_data2_index
;
626 int old_sbss_index
, old_mdebug_index
;
627 struct stat stat_buf
;
629 /* Open the old file & map it into the address space. */
631 old_file
= open (old_name
, O_RDONLY
);
634 fatal ("Can't open %s for reading: errno %d\n", old_name
, errno
);
636 if (fstat (old_file
, &stat_buf
) == -1)
637 fatal ("Can't fstat (%s): errno %d\n", old_name
, errno
);
639 old_base
= mmap ((caddr_t
) 0, stat_buf
.st_size
, PROT_READ
, MAP_SHARED
,
642 if (old_base
== (caddr_t
) -1)
643 fatal ("Can't mmap (%s): errno %d\n", old_name
, errno
);
646 fprintf (stderr
, "mmap (%s, %x) -> %x\n", old_name
, stat_buf
.st_size
,
650 /* Get pointers to headers & section names */
652 old_file_h
= (ElfW(Ehdr
) *) old_base
;
653 old_program_h
= (ElfW(Phdr
) *) ((byte
*) old_base
+ old_file_h
->e_phoff
);
654 old_section_h
= (ElfW(Shdr
) *) ((byte
*) old_base
+ old_file_h
->e_shoff
);
655 old_section_names
= (char *) old_base
656 + OLD_SECTION_H (old_file_h
->e_shstrndx
).sh_offset
;
658 /* Find the old .bss section. Figure out parameters of the new
659 * data2 and bss sections.
662 for (old_bss_index
= 1; old_bss_index
< (int) old_file_h
->e_shnum
;
666 fprintf (stderr
, "Looking for .bss - found %s\n",
667 old_section_names
+ OLD_SECTION_H (old_bss_index
).sh_name
);
669 if (!strcmp (old_section_names
+ OLD_SECTION_H (old_bss_index
).sh_name
,
670 ELF_BSS_SECTION_NAME
))
673 if (old_bss_index
== old_file_h
->e_shnum
)
674 fatal ("Can't find .bss in %s.\n", old_name
, 0);
676 for (old_sbss_index
= 1; old_sbss_index
< (int) old_file_h
->e_shnum
;
680 fprintf (stderr
, "Looking for .sbss - found %s\n",
681 old_section_names
+ OLD_SECTION_H (old_sbss_index
).sh_name
);
683 if (!strcmp (old_section_names
+ OLD_SECTION_H (old_sbss_index
).sh_name
,
687 if (old_sbss_index
== old_file_h
->e_shnum
)
690 old_bss_addr
= OLD_SECTION_H(old_bss_index
).sh_addr
;
691 old_bss_size
= OLD_SECTION_H(old_bss_index
).sh_size
;
692 new_data2_offset
= OLD_SECTION_H(old_bss_index
).sh_offset
;
693 new_data2_index
= old_bss_index
;
697 old_bss_addr
= OLD_SECTION_H(old_sbss_index
).sh_addr
;
698 old_bss_size
= OLD_SECTION_H(old_bss_index
).sh_size
699 + OLD_SECTION_H(old_sbss_index
).sh_size
;
700 new_data2_offset
= OLD_SECTION_H(old_sbss_index
).sh_offset
;
701 new_data2_index
= old_sbss_index
;
704 for (old_mdebug_index
= 1; old_mdebug_index
< (int) old_file_h
->e_shnum
;
708 fprintf (stderr
, "Looking for .mdebug - found %s\n",
709 old_section_names
+ OLD_SECTION_H (old_mdebug_index
).sh_name
);
711 if (!strcmp (old_section_names
+ OLD_SECTION_H (old_mdebug_index
).sh_name
,
715 if (old_mdebug_index
== old_file_h
->e_shnum
)
716 old_mdebug_index
= 0;
718 #if defined (emacs) || !defined (DEBUG)
719 new_bss_addr
= (ElfW(Addr
)) sbrk (0);
721 new_bss_addr
= old_bss_addr
+ old_bss_size
+ 0x1234;
723 new_data2_addr
= old_bss_addr
;
724 new_data2_size
= new_bss_addr
- old_bss_addr
;
727 fprintf (stderr
, "old_bss_index %d\n", old_bss_index
);
728 fprintf (stderr
, "old_bss_addr %x\n", old_bss_addr
);
729 fprintf (stderr
, "old_bss_size %x\n", old_bss_size
);
730 fprintf (stderr
, "new_bss_addr %x\n", new_bss_addr
);
731 fprintf (stderr
, "new_data2_addr %x\n", new_data2_addr
);
732 fprintf (stderr
, "new_data2_size %x\n", new_data2_size
);
733 fprintf (stderr
, "new_data2_offset %x\n", new_data2_offset
);
736 if ((unsigned) new_bss_addr
< (unsigned) old_bss_addr
+ old_bss_size
)
737 fatal (".bss shrank when undumping???\n", 0, 0);
739 /* Set the output file to the right size and mmap it. Set
740 * pointers to various interesting objects. stat_buf still has
744 new_file
= open (new_name
, O_RDWR
| O_CREAT
, 0666);
746 fatal ("Can't creat (%s): errno %d\n", new_name
, errno
);
748 new_file_size
= stat_buf
.st_size
+ old_file_h
->e_shentsize
+ new_data2_size
;
750 if (ftruncate (new_file
, new_file_size
))
751 fatal ("Can't ftruncate (%s): errno %d\n", new_name
, errno
);
753 #ifdef UNEXEC_USE_MAP_PRIVATE
754 new_base
= mmap ((caddr_t
) 0, new_file_size
, PROT_READ
| PROT_WRITE
,
755 MAP_PRIVATE
, new_file
, 0);
757 new_base
= mmap ((caddr_t
) 0, new_file_size
, PROT_READ
| PROT_WRITE
,
758 MAP_SHARED
, new_file
, 0);
761 if (new_base
== (caddr_t
) -1)
762 fatal ("Can't mmap (%s): errno %d\n", new_name
, errno
);
764 new_file_h
= (ElfW(Ehdr
) *) new_base
;
765 new_program_h
= (ElfW(Phdr
) *) ((byte
*) new_base
+ old_file_h
->e_phoff
);
766 new_section_h
= (ElfW(Shdr
) *)
767 ((byte
*) new_base
+ old_file_h
->e_shoff
+ new_data2_size
);
769 /* Make our new file, program and section headers as copies of the
773 memcpy (new_file_h
, old_file_h
, old_file_h
->e_ehsize
);
774 memcpy (new_program_h
, old_program_h
,
775 old_file_h
->e_phnum
* old_file_h
->e_phentsize
);
777 /* Modify the e_shstrndx if necessary. */
778 PATCH_INDEX (new_file_h
->e_shstrndx
);
780 /* Fix up file header. We'll add one section. Section header is
784 new_file_h
->e_shoff
+= new_data2_size
;
785 new_file_h
->e_shnum
+= 1;
788 fprintf (stderr
, "Old section offset %x\n", old_file_h
->e_shoff
);
789 fprintf (stderr
, "Old section count %d\n", old_file_h
->e_shnum
);
790 fprintf (stderr
, "New section offset %x\n", new_file_h
->e_shoff
);
791 fprintf (stderr
, "New section count %d\n", new_file_h
->e_shnum
);
794 /* Fix up a new program header. Extend the writable data segment so
795 * that the bss area is covered too. Find that segment by looking
796 * for a segment that ends just before the .bss area. Make sure
797 * that no segments are above the new .data2. Put a loop at the end
798 * to adjust the offset and address of any segment that is above
799 * data2, just in case we decide to allow this later.
802 for (n
= new_file_h
->e_phnum
- 1; n
>= 0; n
--)
804 /* Compute maximum of all requirements for alignment of section. */
805 ElfW(Word
) alignment
= (NEW_PROGRAM_H (n
)).p_align
;
806 if ((OLD_SECTION_H (old_bss_index
)).sh_addralign
> alignment
)
807 alignment
= OLD_SECTION_H (old_bss_index
).sh_addralign
;
810 /* According to r02kar@x4u2.desy.de (Karsten Kuenne)
811 and oliva@gnu.org (Alexandre Oliva), on IRIX 5.2, we
812 always get "Program segment above .bss" when dumping
813 when the executable doesn't have an sbss section. */
814 if (old_sbss_index
!= -1)
816 if (NEW_PROGRAM_H (n
).p_vaddr
+ NEW_PROGRAM_H (n
).p_filesz
817 > (old_sbss_index
== -1
819 : round_up (old_bss_addr
, alignment
)))
820 fatal ("Program segment above .bss in %s\n", old_name
, 0);
822 if (NEW_PROGRAM_H (n
).p_type
== PT_LOAD
823 && (round_up ((NEW_PROGRAM_H (n
)).p_vaddr
824 + (NEW_PROGRAM_H (n
)).p_filesz
,
826 == round_up (old_bss_addr
, alignment
)))
830 fatal ("Couldn't find segment next to .bss in %s\n", old_name
, 0);
832 /* Make sure that the size includes any padding before the old .bss
834 NEW_PROGRAM_H (n
).p_filesz
= new_bss_addr
- NEW_PROGRAM_H (n
).p_vaddr
;
835 NEW_PROGRAM_H (n
).p_memsz
= NEW_PROGRAM_H (n
).p_filesz
;
837 #if 0 /* Maybe allow section after data2 - does this ever happen? */
838 for (n
= new_file_h
->e_phnum
- 1; n
>= 0; n
--)
840 if (NEW_PROGRAM_H (n
).p_vaddr
841 && NEW_PROGRAM_H (n
).p_vaddr
>= new_data2_addr
)
842 NEW_PROGRAM_H (n
).p_vaddr
+= new_data2_size
- old_bss_size
;
844 if (NEW_PROGRAM_H (n
).p_offset
>= new_data2_offset
)
845 NEW_PROGRAM_H (n
).p_offset
+= new_data2_size
;
849 /* Fix up section headers based on new .data2 section. Any section
850 * whose offset or virtual address is after the new .data2 section
851 * gets its value adjusted. .bss size becomes zero and new address
852 * is set. data2 section header gets added by copying the existing
853 * .data header and modifying the offset, address and size.
855 for (old_data_index
= 1; old_data_index
< (int) old_file_h
->e_shnum
;
857 if (!strcmp (old_section_names
+ OLD_SECTION_H (old_data_index
).sh_name
,
860 if (old_data_index
== old_file_h
->e_shnum
)
861 fatal ("Can't find .data in %s.\n", old_name
, 0);
863 /* Walk through all section headers, insert the new data2 section right
864 before the new bss section. */
865 for (n
= 1, nn
= 1; n
< (int) old_file_h
->e_shnum
; n
++, nn
++)
868 /* If it is (s)bss section, insert the new data2 section before it. */
869 /* new_data2_index is the index of either old_sbss or old_bss, that was
870 chosen as a section for new_data2. */
871 if (n
== new_data2_index
)
873 /* Steal the data section header for this data2 section. */
874 memcpy (&NEW_SECTION_H (nn
), &OLD_SECTION_H (old_data_index
),
875 new_file_h
->e_shentsize
);
877 NEW_SECTION_H (nn
).sh_addr
= new_data2_addr
;
878 NEW_SECTION_H (nn
).sh_offset
= new_data2_offset
;
879 NEW_SECTION_H (nn
).sh_size
= new_data2_size
;
880 /* Use the bss section's alignment. This will assure that the
881 new data2 section always be placed in the same spot as the old
882 bss section by any other application. */
883 NEW_SECTION_H (nn
).sh_addralign
= OLD_SECTION_H (n
).sh_addralign
;
885 /* Now copy over what we have in the memory now. */
886 memcpy (NEW_SECTION_H (nn
).sh_offset
+ new_base
,
887 (caddr_t
) OLD_SECTION_H (n
).sh_addr
,
892 memcpy (&NEW_SECTION_H (nn
), &OLD_SECTION_H (n
),
893 old_file_h
->e_shentsize
);
895 if (n
== old_bss_index
896 /* The new bss and sbss section's size is zero, and its file offset
897 and virtual address should be off by NEW_DATA2_SIZE. */
898 || n
== old_sbss_index
901 /* NN should be `old_s?bss_index + 1' at this point. */
902 NEW_SECTION_H (nn
).sh_offset
=
903 NEW_SECTION_H (new_data2_index
).sh_offset
+ new_data2_size
;
904 NEW_SECTION_H (nn
).sh_addr
=
905 NEW_SECTION_H (new_data2_index
).sh_addr
+ new_data2_size
;
906 /* Let the new bss section address alignment be the same as the
907 section address alignment followed the old bss section, so
908 this section will be placed in exactly the same place. */
909 NEW_SECTION_H (nn
).sh_addralign
= OLD_SECTION_H (nn
).sh_addralign
;
910 NEW_SECTION_H (nn
).sh_size
= 0;
914 /* Any section that was original placed AFTER the bss
915 section should now be off by NEW_DATA2_SIZE. */
916 #ifdef SOLARIS_POWERPC
917 /* On PPC Reference Platform running Solaris 2.5.1
918 the plt section is also of type NOBI like the bss section.
919 (not really stored) and therefore sections after the bss
920 section start at the plt offset. The plt section is always
921 the one just before the bss section.
922 It would be better to put the new data section before
923 the .plt section, or use libelf instead.
924 Erik Deumens, deumens@qtp.ufl.edu. */
925 if (NEW_SECTION_H (nn
).sh_offset
926 >= OLD_SECTION_H (old_bss_index
-1).sh_offset
)
927 NEW_SECTION_H (nn
).sh_offset
+= new_data2_size
;
929 /* The idea of this is that the bss section's sh_offset
930 may need rounding up to compare with new_data2_offset.
931 So we cannot simply compare the sh_offset.
932 However, another small section could exist just before
933 the bss section, and we need to know that is before. */
934 if (round_up (NEW_SECTION_H (nn
).sh_offset
935 + NEW_SECTION_H (nn
).sh_size
,
936 OLD_SECTION_H (old_bss_index
).sh_addralign
)
938 NEW_SECTION_H (nn
).sh_offset
+= new_data2_size
;
940 /* Any section that was originally placed after the section
941 header table should now be off by the size of one section
942 header table entry. */
943 if (NEW_SECTION_H (nn
).sh_offset
> new_file_h
->e_shoff
)
944 NEW_SECTION_H (nn
).sh_offset
+= new_file_h
->e_shentsize
;
947 /* If any section hdr refers to the section after the new .data
948 section, make it refer to next one because we have inserted
949 a new section in between. */
951 PATCH_INDEX (NEW_SECTION_H (nn
).sh_link
);
952 /* For symbol tables, info is a symbol table index,
953 so don't change it. */
954 if (NEW_SECTION_H (nn
).sh_type
!= SHT_SYMTAB
955 && NEW_SECTION_H (nn
).sh_type
!= SHT_DYNSYM
)
956 PATCH_INDEX (NEW_SECTION_H (nn
).sh_info
);
958 /* Now, start to copy the content of sections. */
959 if (NEW_SECTION_H (nn
).sh_type
== SHT_NULL
960 || NEW_SECTION_H (nn
).sh_type
== SHT_NOBITS
)
963 /* Write out the sections. .data and .data1 (and data2, called
964 ".data" in the strings table) get copied from the current process
965 instead of the old file. */
966 if (!strcmp (old_section_names
+ NEW_SECTION_H (n
).sh_name
, ".data")
967 || !strcmp ((old_section_names
+ NEW_SECTION_H (n
).sh_name
),
969 || !strcmp ((old_section_names
+ NEW_SECTION_H (n
).sh_name
),
971 || !strcmp ((old_section_names
+ NEW_SECTION_H (n
).sh_name
),
973 || !strcmp ((old_section_names
+ NEW_SECTION_H (n
).sh_name
),
975 || !strcmp ((old_section_names
+ NEW_SECTION_H (n
).sh_name
),
977 || !strcmp ((old_section_names
+ NEW_SECTION_H (n
).sh_name
),
979 src
= (caddr_t
) OLD_SECTION_H (n
).sh_addr
;
981 src
= old_base
+ OLD_SECTION_H (n
).sh_offset
;
983 memcpy (NEW_SECTION_H (nn
).sh_offset
+ new_base
, src
,
984 NEW_SECTION_H (nn
).sh_size
);
987 /* Update Alpha COFF symbol table: */
988 if (strcmp (old_section_names
+ OLD_SECTION_H (n
).sh_name
, ".mdebug")
991 pHDRR symhdr
= (pHDRR
) (NEW_SECTION_H (nn
).sh_offset
+ new_base
);
993 symhdr
->cbLineOffset
+= new_data2_size
;
994 symhdr
->cbDnOffset
+= new_data2_size
;
995 symhdr
->cbPdOffset
+= new_data2_size
;
996 symhdr
->cbSymOffset
+= new_data2_size
;
997 symhdr
->cbOptOffset
+= new_data2_size
;
998 symhdr
->cbAuxOffset
+= new_data2_size
;
999 symhdr
->cbSsOffset
+= new_data2_size
;
1000 symhdr
->cbSsExtOffset
+= new_data2_size
;
1001 symhdr
->cbFdOffset
+= new_data2_size
;
1002 symhdr
->cbRfdOffset
+= new_data2_size
;
1003 symhdr
->cbExtOffset
+= new_data2_size
;
1005 #endif /* __alpha__ */
1007 #if defined (__sony_news) && defined (_SYSTYPE_SYSV)
1008 if (NEW_SECTION_H (nn
).sh_type
== SHT_MIPS_DEBUG
&& old_mdebug_index
)
1010 int diff
= NEW_SECTION_H(nn
).sh_offset
1011 - OLD_SECTION_H(old_mdebug_index
).sh_offset
;
1012 HDRR
*phdr
= (HDRR
*)(NEW_SECTION_H (nn
).sh_offset
+ new_base
);
1016 phdr
->cbLineOffset
+= diff
;
1017 phdr
->cbDnOffset
+= diff
;
1018 phdr
->cbPdOffset
+= diff
;
1019 phdr
->cbSymOffset
+= diff
;
1020 phdr
->cbOptOffset
+= diff
;
1021 phdr
->cbAuxOffset
+= diff
;
1022 phdr
->cbSsOffset
+= diff
;
1023 phdr
->cbSsExtOffset
+= diff
;
1024 phdr
->cbFdOffset
+= diff
;
1025 phdr
->cbRfdOffset
+= diff
;
1026 phdr
->cbExtOffset
+= diff
;
1029 #endif /* __sony_news && _SYSTYPE_SYSV */
1032 /* Adjust the HDRR offsets in .mdebug and copy the
1033 line data if it's in its usual 'hole' in the object.
1034 Makes the new file debuggable with dbx.
1035 patches up two problems: the absolute file offsets
1036 in the HDRR record of .mdebug (see /usr/include/syms.h), and
1037 the ld bug that gets the line table in a hole in the
1038 elf file rather than in the .mdebug section proper.
1039 David Anderson. davea@sgi.com Jan 16,1994. */
1040 if (n
== old_mdebug_index
)
1042 #define MDEBUGADJUST(__ct,__fileaddr) \
1043 if (n_phdrr->__ct > 0) \
1045 n_phdrr->__fileaddr += movement; \
1048 HDRR
* o_phdrr
= (HDRR
*)((byte
*)old_base
+ OLD_SECTION_H (n
).sh_offset
);
1049 HDRR
* n_phdrr
= (HDRR
*)((byte
*)new_base
+ NEW_SECTION_H (nn
).sh_offset
);
1050 unsigned movement
= new_data2_size
;
1052 MDEBUGADJUST (idnMax
, cbDnOffset
);
1053 MDEBUGADJUST (ipdMax
, cbPdOffset
);
1054 MDEBUGADJUST (isymMax
, cbSymOffset
);
1055 MDEBUGADJUST (ioptMax
, cbOptOffset
);
1056 MDEBUGADJUST (iauxMax
, cbAuxOffset
);
1057 MDEBUGADJUST (issMax
, cbSsOffset
);
1058 MDEBUGADJUST (issExtMax
, cbSsExtOffset
);
1059 MDEBUGADJUST (ifdMax
, cbFdOffset
);
1060 MDEBUGADJUST (crfd
, cbRfdOffset
);
1061 MDEBUGADJUST (iextMax
, cbExtOffset
);
1062 /* The Line Section, being possible off in a hole of the object,
1063 requires special handling. */
1064 if (n_phdrr
->cbLine
> 0)
1066 if (o_phdrr
->cbLineOffset
> (OLD_SECTION_H (n
).sh_offset
1067 + OLD_SECTION_H (n
).sh_size
))
1069 /* line data is in a hole in elf. do special copy and adjust
1070 for this ld mistake.
1072 n_phdrr
->cbLineOffset
+= movement
;
1074 memcpy (n_phdrr
->cbLineOffset
+ new_base
,
1075 o_phdrr
->cbLineOffset
+ old_base
, n_phdrr
->cbLine
);
1079 /* somehow line data is in .mdebug as it is supposed to be. */
1080 MDEBUGADJUST (cbLine
, cbLineOffset
);
1086 /* If it is the symbol table, its st_shndx field needs to be patched. */
1087 if (NEW_SECTION_H (nn
).sh_type
== SHT_SYMTAB
1088 || NEW_SECTION_H (nn
).sh_type
== SHT_DYNSYM
)
1090 ElfW(Shdr
) *spt
= &NEW_SECTION_H (nn
);
1091 unsigned int num
= spt
->sh_size
/ spt
->sh_entsize
;
1092 ElfW(Sym
) * sym
= (ElfW(Sym
) *) (NEW_SECTION_H (nn
).sh_offset
+
1094 for (; num
--; sym
++)
1096 if ((sym
->st_shndx
== SHN_UNDEF
)
1097 || (sym
->st_shndx
== SHN_ABS
)
1098 || (sym
->st_shndx
== SHN_COMMON
))
1101 PATCH_INDEX (sym
->st_shndx
);
1106 /* Update the symbol values of _edata and _end. */
1107 for (n
= new_file_h
->e_shnum
- 1; n
; n
--)
1110 ElfW(Sym
) *symp
, *symendp
;
1112 if (NEW_SECTION_H (n
).sh_type
!= SHT_DYNSYM
1113 && NEW_SECTION_H (n
).sh_type
!= SHT_SYMTAB
)
1116 symnames
= ((byte
*) new_base
1117 + NEW_SECTION_H (NEW_SECTION_H (n
).sh_link
).sh_offset
);
1118 symp
= (ElfW(Sym
) *) (NEW_SECTION_H (n
).sh_offset
+ new_base
);
1119 symendp
= (ElfW(Sym
) *) ((byte
*)symp
+ NEW_SECTION_H (n
).sh_size
);
1121 for (; symp
< symendp
; symp
++)
1122 if (strcmp ((char *) (symnames
+ symp
->st_name
), "_end") == 0
1123 || strcmp ((char *) (symnames
+ symp
->st_name
), "end") == 0
1124 || strcmp ((char *) (symnames
+ symp
->st_name
), "_edata") == 0
1125 || strcmp ((char *) (symnames
+ symp
->st_name
), "edata") == 0)
1126 memcpy (&symp
->st_value
, &new_bss_addr
, sizeof (new_bss_addr
));
1129 /* This loop seeks out relocation sections for the data section, so
1130 that it can undo relocations performed by the runtime linker. */
1131 for (n
= new_file_h
->e_shnum
- 1; n
; n
--)
1133 ElfW(Shdr
) section
= NEW_SECTION_H (n
);
1134 switch (section
.sh_type
) {
1139 /* This code handles two different size structs, but there should
1140 be no harm in that provided that r_offset is always the first
1142 nn
= section
.sh_info
;
1143 if (!strcmp (old_section_names
+ NEW_SECTION_H (nn
).sh_name
, ".data")
1144 || !strcmp ((old_section_names
+ NEW_SECTION_H (nn
).sh_name
),
1146 || !strcmp ((old_section_names
+ NEW_SECTION_H (nn
).sh_name
),
1148 || !strcmp ((old_section_names
+ NEW_SECTION_H (nn
).sh_name
),
1150 || !strcmp ((old_section_names
+ NEW_SECTION_H (nn
).sh_name
),
1152 || !strcmp ((old_section_names
+ NEW_SECTION_H (nn
).sh_name
),
1154 || !strcmp ((old_section_names
+ NEW_SECTION_H (nn
).sh_name
),
1157 ElfW(Addr
) offset
= NEW_SECTION_H (nn
).sh_addr
-
1158 NEW_SECTION_H (nn
).sh_offset
;
1159 caddr_t reloc
= old_base
+ section
.sh_offset
, end
;
1160 for (end
= reloc
+ section
.sh_size
; reloc
< end
;
1161 reloc
+= section
.sh_entsize
)
1163 ElfW(Addr
) addr
= ((ElfW(Rel
) *) reloc
)->r_offset
- offset
;
1165 /* The Alpha ELF binutils currently have a bug that
1166 sometimes results in relocs that contain all
1167 zeroes. Work around this for now... */
1168 if (((ElfW(Rel
) *) reloc
)->r_offset
== 0)
1171 memcpy (new_base
+ addr
, old_base
+ addr
, sizeof(ElfW(Addr
)));
1178 #ifdef UNEXEC_USE_MAP_PRIVATE
1179 if (lseek (new_file
, 0, SEEK_SET
) == -1)
1180 fatal ("Can't rewind (%s): errno %d\n", new_name
, errno
);
1182 if (write (new_file
, new_base
, new_file_size
) != new_file_size
)
1183 fatal ("Can't write (%s): errno %d\n", new_name
, errno
);
1186 /* Close the files and make the new file executable. */
1188 if (close (old_file
))
1189 fatal ("Can't close (%s): errno %d\n", old_name
, errno
);
1191 if (close (new_file
))
1192 fatal ("Can't close (%s): errno %d\n", new_name
, errno
);
1194 if (stat (new_name
, &stat_buf
) == -1)
1195 fatal ("Can't stat (%s): errno %d\n", new_name
, errno
);
1199 stat_buf
.st_mode
|= 0111 & ~n
;
1200 if (chmod (new_name
, stat_buf
.st_mode
) == -1)
1201 fatal ("Can't chmod (%s): errno %d\n", new_name
, errno
);