1 /* Copyright (C) 1985, 1986, 1987, 1988, 1990, 1992, 1993
2 Free Software Foundation, Inc.
4 This file is part of XEmacs.
6 XEmacs is free software; you can redistribute it and/or modify it
7 under the terms of the GNU General Public License as published by the
8 Free Software Foundation; either version 2, or (at your option) any
11 XEmacs is distributed in the hope that it will be useful, but WITHOUT
12 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 You should have received a copy of the GNU General Public License
17 along with XEmacs; 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 /* Synched up with: FSF 20.4. */
24 * unexec.c - Convert a running program into an a.out file.
26 * Author: Spencer W. Thomas
27 * Computer Science Dept.
29 * Date: Tue Mar 2 1982
30 * Modified heavily since then.
33 * unexec (new_name, a_name, data_start, bss_start, entry_address)
34 * char *new_name, *a_name;
35 * unsigned data_start, bss_start, entry_address;
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 a_name is non-NULL, the symbol table will be taken from the given file.
40 * On some machines, an existing a_name file is required.
42 * The boundaries within the a.out file may be adjusted with the data_start
43 * and bss_start arguments. Either or both may be given as 0 for defaults.
45 * Data_start gives the boundary between the text segment and the data
46 * segment of the program. The text segment can contain shared, read-only
47 * program code and literal data, while the data segment is always unshared
48 * and unprotected. Data_start gives the lowest unprotected address.
49 * The value you specify may be rounded down to a suitable boundary
50 * as required by the machine you are using.
52 * Specifying zero for data_start means the boundary between text and data
53 * should not be the same as when the program was loaded.
54 * If NO_REMAP is defined, the argument data_start is ignored and the
55 * segment boundaries are never changed.
57 * Bss_start indicates how much of the data segment is to be saved in the
58 * a.out file and restored when the program is executed. It gives the lowest
59 * unsaved address, and is rounded up to a page boundary. The default when 0
60 * is given assumes that the entire data segment is to be stored, including
61 * the previous data and bss as well as any additional storage allocated with
64 * The new file is set up to start at entry_address.
66 * If you make improvements I'd like to get them too.
67 * harpo!utah-cs!thomas, thomas@Utah-20
71 /* Even more heavily modified by james@bigtex.cactus.org of Dell Computer Co.
74 * Basic theory: the data space of the running process needs to be
75 * dumped to the output file. Normally we would just enlarge the size
76 * of .data, scooting everything down. But we can't do that in ELF,
77 * because there is often something between the .data space and the
80 * In the temacs dump below, notice that the Global Offset Table
81 * (.got) and the Dynamic link data (.dynamic) come between .data1 and
82 * .bss. It does not work to overlap .data with these fields.
84 * The solution is to create a new .data segment. This segment is
85 * filled with data from the current process. Since the contents of
86 * various sections refer to sections by index, the new .data segment
87 * is made the last in the table to avoid changing any existing index.
89 * This is an example of how the section headers are changed. "Addr"
90 * is a process virtual address. "Offset" is a file offset.
92 raid:/nfs/raid/src/dist-18.56/src> dump -h temacs
96 **** SECTION HEADER TABLE ****
97 [No] Type Flags Addr Offset Size Name
98 Link Info Adralgn Entsize
100 [1] 1 2 0x80480d4 0xd4 0x13 .interp
103 [2] 5 2 0x80480e8 0xe8 0x388 .hash
106 [3] 11 2 0x8048470 0x470 0x7f0 .dynsym
109 [4] 3 2 0x8048c60 0xc60 0x3ad .dynstr
112 [5] 9 2 0x8049010 0x1010 0x338 .rel.plt
115 [6] 1 6 0x8049348 0x1348 0x3 .init
118 [7] 1 6 0x804934c 0x134c 0x680 .plt
121 [8] 1 6 0x80499cc 0x19cc 0x3c56f .text
124 [9] 1 6 0x8085f3c 0x3df3c 0x3 .fini
127 [10] 1 2 0x8085f40 0x3df40 0x69c .rodata
130 [11] 1 2 0x80865dc 0x3e5dc 0xd51 .rodata1
133 [12] 1 3 0x8088330 0x3f330 0x20afc .data
136 [13] 1 3 0x80a8e2c 0x5fe2c 0x89d .data1
139 [14] 1 3 0x80a96cc 0x606cc 0x1a8 .got
142 [15] 6 3 0x80a9874 0x60874 0x80 .dynamic
145 [16] 8 3 0x80a98f4 0x608f4 0x449c .bss
148 [17] 2 0 0 0x608f4 0x9b90 .symtab
151 [18] 3 0 0 0x6a484 0x8526 .strtab
154 [19] 3 0 0 0x729aa 0x93 .shstrtab
157 [20] 1 0 0 0x72a3d 0x68b7 .comment
160 raid:/nfs/raid/src/dist-18.56/src> dump -h xemacs
164 **** SECTION HEADER TABLE ****
165 [No] Type Flags Addr Offset Size Name
166 Link Info Adralgn Entsize
168 [1] 1 2 0x80480d4 0xd4 0x13 .interp
171 [2] 5 2 0x80480e8 0xe8 0x388 .hash
174 [3] 11 2 0x8048470 0x470 0x7f0 .dynsym
177 [4] 3 2 0x8048c60 0xc60 0x3ad .dynstr
180 [5] 9 2 0x8049010 0x1010 0x338 .rel.plt
183 [6] 1 6 0x8049348 0x1348 0x3 .init
186 [7] 1 6 0x804934c 0x134c 0x680 .plt
189 [8] 1 6 0x80499cc 0x19cc 0x3c56f .text
192 [9] 1 6 0x8085f3c 0x3df3c 0x3 .fini
195 [10] 1 2 0x8085f40 0x3df40 0x69c .rodata
198 [11] 1 2 0x80865dc 0x3e5dc 0xd51 .rodata1
201 [12] 1 3 0x8088330 0x3f330 0x20afc .data
204 [13] 1 3 0x80a8e2c 0x5fe2c 0x89d .data1
207 [14] 1 3 0x80a96cc 0x606cc 0x1a8 .got
210 [15] 6 3 0x80a9874 0x60874 0x80 .dynamic
213 [16] 8 3 0x80c6800 0x7d800 0 .bss
216 [17] 2 0 0 0x7d800 0x9b90 .symtab
219 [18] 3 0 0 0x87390 0x8526 .strtab
222 [19] 3 0 0 0x8f8b6 0x93 .shstrtab
225 [20] 1 0 0 0x8f949 0x68b7 .comment
228 [21] 1 3 0x80a98f4 0x608f4 0x1cf0c .data
231 * This is an example of how the file header is changed. "Shoff" is
232 * the section header offset within the file. Since that table is
233 * after the new .data section, it is moved. "Shnum" is the number of
234 * sections, which we increment.
236 * "Phoff" is the file offset to the program header. "Phentsize" and
237 * "Shentsz" are the program and section header entries sizes respectively.
238 * These can be larger than the apparent struct sizes.
240 raid:/nfs/raid/src/dist-18.56/src> dump -f temacs
245 Class Data Type Machine Version
246 Entry Phoff Shoff Flags Ehsize
247 Phentsize Phnum Shentsz Shnum Shstrndx
250 0x80499cc 0x34 0x792f4 0 0x34
253 raid:/nfs/raid/src/dist-18.56/src> dump -f xemacs
258 Class Data Type Machine Version
259 Entry Phoff Shoff Flags Ehsize
260 Phentsize Phnum Shentsz Shnum Shstrndx
263 0x80499cc 0x34 0x96200 0 0x34
266 * These are the program headers. "Offset" is the file offset to the
267 * segment. "Vaddr" is the memory load address. "Filesz" is the
268 * segment size as it appears in the file, and "Memsz" is the size in
269 * memory. Below, the third segment is the code and the fourth is the
270 * data: the difference between Filesz and Memsz is .bss
272 raid:/nfs/raid/src/dist-18.56/src> dump -o temacs
275 ***** PROGRAM EXECUTION HEADER *****
276 Type Offset Vaddr Paddr
277 Filesz Memsz Flags Align
286 0x3f2f9 0x3f2f9 5 0x1000
288 1 0x3f330 0x8088330 0
289 0x215c4 0x25a60 7 0x1000
291 2 0x60874 0x80a9874 0
294 raid:/nfs/raid/src/dist-18.56/src> dump -o xemacs
297 ***** PROGRAM EXECUTION HEADER *****
298 Type Offset Vaddr Paddr
299 Filesz Memsz Flags Align
308 0x3f2f9 0x3f2f9 5 0x1000
310 1 0x3f330 0x8088330 0
311 0x3e4d0 0x3e4d0 7 0x1000
313 2 0x60874 0x80a9874 0
319 /* Modified by wtien@urbana.mcd.mot.com of Motorola Inc.
321 * The above mechanism does not work if the unexeced ELF file is being
322 * re-layout by other applications (such as `strip'). All the applications
323 * that re-layout the internal of ELF will layout all sections in ascending
324 * order of their file offsets. After the re-layout, the data2 section will
325 * still be the LAST section in the section header vector, but its file offset
326 * is now being pushed far away down, and causes part of it not to be mapped
327 * in (ie. not covered by the load segment entry in PHDR vector), therefore
328 * causes the new binary to fail.
330 * The solution is to modify the unexec algorithm to insert the new data2
331 * section header right before the new bss section header, so their file
332 * offsets will be in the ascending order. Since some of the section's (all
333 * sections AFTER the bss section) indexes are now changed, we also need to
334 * modify some fields to make them point to the right sections. This is done
335 * by macro PATCH_INDEX. All the fields that need to be patched are:
337 * 1. ELF header e_shstrndx field.
338 * 2. section header sh_link and sh_info field.
339 * 3. symbol table entry st_shndx field.
341 * The above example now should look like:
343 **** SECTION HEADER TABLE ****
344 [No] Type Flags Addr Offset Size Name
345 Link Info Adralgn Entsize
347 [1] 1 2 0x80480d4 0xd4 0x13 .interp
350 [2] 5 2 0x80480e8 0xe8 0x388 .hash
353 [3] 11 2 0x8048470 0x470 0x7f0 .dynsym
356 [4] 3 2 0x8048c60 0xc60 0x3ad .dynstr
359 [5] 9 2 0x8049010 0x1010 0x338 .rel.plt
362 [6] 1 6 0x8049348 0x1348 0x3 .init
365 [7] 1 6 0x804934c 0x134c 0x680 .plt
368 [8] 1 6 0x80499cc 0x19cc 0x3c56f .text
371 [9] 1 6 0x8085f3c 0x3df3c 0x3 .fini
374 [10] 1 2 0x8085f40 0x3df40 0x69c .rodata
377 [11] 1 2 0x80865dc 0x3e5dc 0xd51 .rodata1
380 [12] 1 3 0x8088330 0x3f330 0x20afc .data
383 [13] 1 3 0x80a8e2c 0x5fe2c 0x89d .data1
386 [14] 1 3 0x80a96cc 0x606cc 0x1a8 .got
389 [15] 6 3 0x80a9874 0x60874 0x80 .dynamic
392 [16] 1 3 0x80a98f4 0x608f4 0x1cf0c .data
395 [17] 8 3 0x80c6800 0x7d800 0 .bss
398 [18] 2 0 0 0x7d800 0x9b90 .symtab
401 [19] 3 0 0 0x87390 0x8526 .strtab
404 [20] 3 0 0 0x8f8b6 0x93 .shstrtab
407 [21] 1 0 0 0x8f949 0x68b7 .comment
413 #define fatal(a, b, c) fprintf (stderr, a, b, c), exit (1)
416 extern void fatal (CONST char *, ...);
419 #include <sys/types.h>
421 #include <sys/stat.h>
427 #if !defined (__NetBSD__) && !defined (__OpenBSD__)
430 #include <sys/mman.h>
431 #if defined (__sony_news) && defined (_SYSTYPE_SYSV)
432 #include <sys/elf_mips.h>
434 #endif /* __sony_news && _SYSTYPE_SYSV */
436 #include <sym.h> /* for HDRR declaration */
439 #if defined (__alpha__) && !defined (__NetBSD__) && !defined (__OpenBSD__)
440 /* Declare COFF debugging symbol table. This used to be in
441 /usr/include/sym.h, but this file is no longer included in Red Hat
442 5.0 and presumably in any other glibc 2.x based distribution. */
470 #define cbHDRR sizeof(HDRR)
471 #define hdrNil ((pHDRR)0)
476 * NetBSD does not have normal-looking user-land ELF support.
483 # include <sys/exec_elf.h>
485 # define PT_LOAD Elf_pt_load
486 # define SHT_SYMTAB Elf_sht_symtab
487 # define SHT_DYNSYM Elf_sht_dynsym
488 # define SHT_NULL Elf_sht_null
489 # define SHT_NOBITS Elf_sht_nobits
490 # define SHT_REL Elf_sht_rel
491 # define SHT_RELA Elf_sht_rela
493 # define SHN_UNDEF Elf_eshn_undefined
494 # define SHN_ABS Elf_eshn_absolute
495 # define SHN_COMMON Elf_eshn_common
498 * The magic of picking the right size types is handled by the ELFSIZE
502 # define ElfW(type) Elf_##type
504 # define ElfW(type) Elf_/**/type
508 # include <sys/exec_ecoff.h>
509 # define HDRR struct ecoff_symhdr
510 # define pHDRR HDRR *
512 #endif /* __NetBSD__ */
515 # include <sys/exec_elf.h>
518 #if __GNU_LIBRARY__ - 0 >= 6
519 # include <link.h> /* get ElfW etc */
524 # define ElfW(type) Elf32_##type
526 # define ElfW(type) Elf32_/**/type
530 #ifndef ELF_BSS_SECTION_NAME
531 #define ELF_BSS_SECTION_NAME ".bss"
534 /* Get the address of a particular section or program header entry,
535 * accounting for the size of the entries.
538 On PPC Reference Platform running Solaris 2.5.1
539 the plt section is also of type NOBI like the bss section.
540 (not really stored) and therefore sections after the bss
541 section start at the plt offset. The plt section is always
542 the one just before the bss section.
543 Thus, we modify the test from
544 if (NEW_SECTION_H (nn).sh_offset >= new_data2_offset)
546 if (NEW_SECTION_H (nn).sh_offset >=
547 OLD_SECTION_H (old_bss_index-1).sh_offset)
548 This is just a hack. We should put the new data section
549 before the .plt section.
550 And we should not have this routine at all but use
551 the libelf library to read the old file and create the new
553 The changed code is minimal and depends on prep set in m/prep.h
555 Quantum Theory Project
556 University of Florida
561 #define OLD_SECTION_H(n) \
562 (*(ElfW(Shdr) *) ((byte *) old_section_h + old_file_h->e_shentsize * (n)))
563 #define NEW_SECTION_H(n) \
564 (*(ElfW(Shdr) *) ((byte *) new_section_h + new_file_h->e_shentsize * (n)))
565 #define OLD_PROGRAM_H(n) \
566 (*(ElfW(Phdr) *) ((byte *) old_program_h + old_file_h->e_phentsize * (n)))
567 #define NEW_PROGRAM_H(n) \
568 (*(ElfW(Phdr) *) ((byte *) new_program_h + new_file_h->e_phentsize * (n)))
570 #define PATCH_INDEX(n) \
572 if ((int) (n) >= old_bss_index) \
574 typedef unsigned char byte;
576 /* Round X up to a multiple of Y. */
579 round_up (ElfW(Addr) x, ElfW(Addr) y)
587 /* ****************************************************************
592 * In ELF, this works by replacing the old .bss section with a new
593 * .data section, and inserting an empty .bss immediately afterwards.
596 void unexec (char *new_name, char *old_name, unsigned int data_start,
597 unsigned int bss_start, unsigned int entry_address);
599 unexec (char *new_name, char *old_name, unsigned int data_start,
600 unsigned int bss_start, unsigned int entry_address)
602 int new_file, old_file, new_file_size;
604 /* Pointers to the base of the image of the two files. */
605 caddr_t old_base, new_base;
607 /* Pointers to the file, program and section headers for the old and new
610 ElfW(Ehdr) *old_file_h, *new_file_h;
611 ElfW(Phdr) *old_program_h, *new_program_h;
612 ElfW(Shdr) *old_section_h, *new_section_h;
614 /* Point to the section name table in the old file */
615 char *old_section_names;
617 ElfW(Addr) old_bss_addr, new_bss_addr;
618 ElfW(Word) old_bss_size, new_data2_size;
619 ElfW(Off) new_data2_offset;
620 ElfW(Addr) new_data2_addr;
622 int n, nn, old_bss_index, old_data_index, new_data2_index;
623 int old_sbss_index, old_mdebug_index;
624 struct stat stat_buf;
626 /* Open the old file & map it into the address space. */
628 old_file = open (old_name, O_RDONLY);
631 fatal ("Can't open %s for reading: errno %d\n", old_name, errno);
633 if (fstat (old_file, &stat_buf) == -1)
634 fatal ("Can't fstat (%s): errno %d\n", old_name, errno);
636 old_base = (caddr_t) mmap (0, stat_buf.st_size, PROT_READ, MAP_SHARED, old_file, 0);
638 if (old_base == (caddr_t) -1)
639 fatal ("Can't mmap (%s): errno %d\n", old_name, errno);
642 fprintf (stderr, "mmap (%s, %x) -> %x\n", old_name, stat_buf.st_size,
646 /* Get pointers to headers & section names */
648 old_file_h = (ElfW(Ehdr) *) old_base;
649 old_program_h = (ElfW(Phdr) *) ((byte *) old_base + old_file_h->e_phoff);
650 old_section_h = (ElfW(Shdr) *) ((byte *) old_base + old_file_h->e_shoff);
651 old_section_names = (char *) old_base
652 + OLD_SECTION_H (old_file_h->e_shstrndx).sh_offset;
654 /* Find the old .bss section. Figure out parameters of the new
655 * data2 and bss sections.
658 for (old_bss_index = 1; old_bss_index < (int) old_file_h->e_shnum;
662 fprintf (stderr, "Looking for .bss - found %s\n",
663 old_section_names + OLD_SECTION_H (old_bss_index).sh_name);
665 if (!strcmp (old_section_names + OLD_SECTION_H (old_bss_index).sh_name,
666 ELF_BSS_SECTION_NAME))
669 if (old_bss_index == old_file_h->e_shnum)
670 fatal ("Can't find .bss in %s.\n", old_name, 0);
672 for (old_sbss_index = 1; old_sbss_index < (int) old_file_h->e_shnum;
676 fprintf (stderr, "Looking for .sbss - found %s\n",
677 old_section_names + OLD_SECTION_H (old_sbss_index).sh_name);
679 if (!strcmp (old_section_names + OLD_SECTION_H (old_sbss_index).sh_name,
683 if (old_sbss_index == old_file_h->e_shnum)
686 old_bss_addr = OLD_SECTION_H(old_bss_index).sh_addr;
687 old_bss_size = OLD_SECTION_H(old_bss_index).sh_size;
688 new_data2_offset = OLD_SECTION_H(old_bss_index).sh_offset;
689 new_data2_index = old_bss_index;
693 old_bss_addr = OLD_SECTION_H(old_sbss_index).sh_addr;
694 old_bss_size = OLD_SECTION_H(old_bss_index).sh_size
695 + OLD_SECTION_H(old_sbss_index).sh_size;
696 new_data2_offset = OLD_SECTION_H(old_sbss_index).sh_offset;
697 new_data2_index = old_sbss_index;
700 for (old_mdebug_index = 1; old_mdebug_index < (int) old_file_h->e_shnum;
704 fprintf (stderr, "Looking for .mdebug - found %s\n",
705 old_section_names + OLD_SECTION_H (old_mdebug_index).sh_name);
707 if (!strcmp (old_section_names + OLD_SECTION_H (old_mdebug_index).sh_name,
711 if (old_mdebug_index == old_file_h->e_shnum)
712 old_mdebug_index = 0;
714 #if defined (emacs) || !defined (DEBUG)
715 new_bss_addr = (ElfW(Addr)) sbrk (0);
717 new_bss_addr = old_bss_addr + old_bss_size + 0x1234;
719 new_data2_addr = old_bss_addr;
720 new_data2_size = new_bss_addr - old_bss_addr;
723 fprintf (stderr, "old_bss_index %d\n", old_bss_index);
724 fprintf (stderr, "old_bss_addr %x\n", old_bss_addr);
725 fprintf (stderr, "old_bss_size %x\n", old_bss_size);
726 fprintf (stderr, "new_bss_addr %x\n", new_bss_addr);
727 fprintf (stderr, "new_data2_addr %x\n", new_data2_addr);
728 fprintf (stderr, "new_data2_size %x\n", new_data2_size);
729 fprintf (stderr, "new_data2_offset %x\n", new_data2_offset);
732 if ((unsigned) new_bss_addr < (unsigned) old_bss_addr + old_bss_size)
733 fatal (".bss shrank when undumping???\n", 0, 0);
735 /* Set the output file to the right size and mmap it. Set
736 * pointers to various interesting objects. stat_buf still has
740 new_file = open (new_name, O_RDWR | O_CREAT, 0666);
742 fatal ("Can't creat (%s): errno %d\n", new_name, errno);
744 new_file_size = stat_buf.st_size + old_file_h->e_shentsize + new_data2_size;
746 if (ftruncate (new_file, new_file_size))
747 fatal ("Can't ftruncate (%s): errno %d\n", new_name, errno);
749 new_base = (caddr_t) mmap (0, new_file_size, PROT_READ | PROT_WRITE,
750 #ifdef UNEXEC_USE_MAP_PRIVATE
757 if (new_base == (caddr_t) -1)
758 fatal ("Can't mmap (%s): errno %d\n", new_name, errno);
760 new_file_h = (ElfW(Ehdr) *) new_base;
761 new_program_h = (ElfW(Phdr) *) ((byte *) new_base + old_file_h->e_phoff);
762 new_section_h = (ElfW(Shdr) *)
763 ((byte *) new_base + old_file_h->e_shoff + new_data2_size);
765 /* Make our new file, program and section headers as copies of the
769 memcpy (new_file_h, old_file_h, old_file_h->e_ehsize);
770 memcpy (new_program_h, old_program_h,
771 old_file_h->e_phnum * old_file_h->e_phentsize);
773 /* Modify the e_shstrndx if necessary. */
774 PATCH_INDEX (new_file_h->e_shstrndx);
776 /* Fix up file header. We'll add one section. Section header is
780 new_file_h->e_shoff += new_data2_size;
781 new_file_h->e_shnum += 1;
784 fprintf (stderr, "Old section offset %x\n", old_file_h->e_shoff);
785 fprintf (stderr, "Old section count %d\n", old_file_h->e_shnum);
786 fprintf (stderr, "New section offset %x\n", new_file_h->e_shoff);
787 fprintf (stderr, "New section count %d\n", new_file_h->e_shnum);
790 /* Fix up a new program header. Extend the writable data segment so
791 * that the bss area is covered too. Find that segment by looking
792 * for a segment that ends just before the .bss area. Make sure
793 * that no segments are above the new .data2. Put a loop at the end
794 * to adjust the offset and address of any segment that is above
795 * data2, just in case we decide to allow this later.
798 for (n = new_file_h->e_phnum - 1; n >= 0; n--)
800 /* Compute maximum of all requirements for alignment of section. */
801 ElfW(Word) alignment = (NEW_PROGRAM_H (n)).p_align;
802 if ((OLD_SECTION_H (old_bss_index)).sh_addralign > alignment)
803 alignment = OLD_SECTION_H (old_bss_index).sh_addralign;
806 /* According to r02kar@x4u2.desy.de (Karsten Kuenne)
807 and oliva@gnu.org (Alexandre Oliva), on IRIX 5.2, we
808 always get "Program segment above .bss" when dumping
809 when the executable doesn't have an sbss section. */
810 if (old_sbss_index != -1)
812 if (NEW_PROGRAM_H (n).p_vaddr + NEW_PROGRAM_H (n).p_filesz
813 > (old_sbss_index == -1
815 : round_up (old_bss_addr, alignment)))
816 fatal ("Program segment above .bss in %s\n", old_name, 0);
818 if (NEW_PROGRAM_H (n).p_type == PT_LOAD
819 && (round_up ((NEW_PROGRAM_H (n)).p_vaddr
820 + (NEW_PROGRAM_H (n)).p_filesz,
822 == round_up (old_bss_addr, alignment)))
826 fatal ("Couldn't find segment next to .bss in %s\n", old_name, 0);
828 /* Make sure that the size includes any padding before the old .bss
830 NEW_PROGRAM_H (n).p_filesz = new_bss_addr - NEW_PROGRAM_H (n).p_vaddr;
831 NEW_PROGRAM_H (n).p_memsz = NEW_PROGRAM_H (n).p_filesz;
833 #if 0 /* Maybe allow section after data2 - does this ever happen? */
834 for (n = new_file_h->e_phnum - 1; n >= 0; n--)
836 if (NEW_PROGRAM_H (n).p_vaddr
837 && NEW_PROGRAM_H (n).p_vaddr >= new_data2_addr)
838 NEW_PROGRAM_H (n).p_vaddr += new_data2_size - old_bss_size;
840 if (NEW_PROGRAM_H (n).p_offset >= new_data2_offset)
841 NEW_PROGRAM_H (n).p_offset += new_data2_size;
845 /* Fix up section headers based on new .data2 section. Any section
846 * whose offset or virtual address is after the new .data2 section
847 * gets its value adjusted. .bss size becomes zero and new address
848 * is set. data2 section header gets added by copying the existing
849 * .data header and modifying the offset, address and size.
851 for (old_data_index = 1; old_data_index < (int) old_file_h->e_shnum;
853 if (!strcmp (old_section_names + OLD_SECTION_H (old_data_index).sh_name,
856 if (old_data_index == old_file_h->e_shnum)
857 fatal ("Can't find .data in %s.\n", old_name, 0);
859 /* Walk through all section headers, insert the new data2 section right
860 before the new bss section. */
861 for (n = 1, nn = 1; n < (int) old_file_h->e_shnum; n++, nn++)
864 /* If it is (s)bss section, insert the new data2 section before it. */
865 /* new_data2_index is the index of either old_sbss or old_bss, that was
866 chosen as a section for new_data2. */
867 if (n == new_data2_index)
869 /* Steal the data section header for this data2 section. */
870 memcpy (&NEW_SECTION_H (nn), &OLD_SECTION_H (old_data_index),
871 new_file_h->e_shentsize);
873 NEW_SECTION_H (nn).sh_addr = new_data2_addr;
874 NEW_SECTION_H (nn).sh_offset = new_data2_offset;
875 NEW_SECTION_H (nn).sh_size = new_data2_size;
876 /* Use the bss section's alignment. This will assure that the
877 new data2 section always be placed in the same spot as the old
878 bss section by any other application. */
879 NEW_SECTION_H (nn).sh_addralign = OLD_SECTION_H (n).sh_addralign;
881 /* Now copy over what we have in the memory now. */
882 memcpy (NEW_SECTION_H (nn).sh_offset + new_base,
883 (caddr_t) OLD_SECTION_H (n).sh_addr,
888 memcpy (&NEW_SECTION_H (nn), &OLD_SECTION_H (n),
889 old_file_h->e_shentsize);
891 if (n == old_bss_index
892 /* The new bss and sbss section's size is zero, and its file offset
893 and virtual address should be off by NEW_DATA2_SIZE. */
894 || n == old_sbss_index
897 /* NN should be `old_s?bss_index + 1' at this point. */
898 NEW_SECTION_H (nn).sh_offset =
899 NEW_SECTION_H (new_data2_index).sh_offset + new_data2_size;
900 NEW_SECTION_H (nn).sh_addr =
901 NEW_SECTION_H (new_data2_index).sh_addr + new_data2_size;
902 /* Let the new bss section address alignment be the same as the
903 section address alignment followed the old bss section, so
904 this section will be placed in exactly the same place. */
905 NEW_SECTION_H (nn).sh_addralign = OLD_SECTION_H (nn).sh_addralign;
906 NEW_SECTION_H (nn).sh_size = 0;
910 /* Any section that was original placed AFTER the bss
911 section should now be off by NEW_DATA2_SIZE. */
912 #ifdef SOLARIS_POWERPC
913 /* On PPC Reference Platform running Solaris 2.5.1
914 the plt section is also of type NOBI like the bss section.
915 (not really stored) and therefore sections after the bss
916 section start at the plt offset. The plt section is always
917 the one just before the bss section.
918 It would be better to put the new data section before
919 the .plt section, or use libelf instead.
920 Erik Deumens, deumens@qtp.ufl.edu. */
921 if (NEW_SECTION_H (nn).sh_offset
922 >= OLD_SECTION_H (old_bss_index-1).sh_offset)
923 NEW_SECTION_H (nn).sh_offset += new_data2_size;
925 if (round_up (NEW_SECTION_H (nn).sh_offset,
926 OLD_SECTION_H (old_bss_index).sh_addralign)
928 NEW_SECTION_H (nn).sh_offset += new_data2_size;
930 /* Any section that was originally placed after the section
931 header table should now be off by the size of one section
932 header table entry. */
933 if (NEW_SECTION_H (nn).sh_offset > new_file_h->e_shoff)
934 NEW_SECTION_H (nn).sh_offset += new_file_h->e_shentsize;
937 /* If any section hdr refers to the section after the new .data
938 section, make it refer to next one because we have inserted
939 a new section in between. */
941 PATCH_INDEX (NEW_SECTION_H (nn).sh_link);
942 /* For symbol tables, info is a symbol table index,
943 so don't change it. */
944 if (NEW_SECTION_H (nn).sh_type != SHT_SYMTAB
945 && NEW_SECTION_H (nn).sh_type != SHT_DYNSYM)
946 PATCH_INDEX (NEW_SECTION_H (nn).sh_info);
948 /* Now, start to copy the content of sections. */
949 if (NEW_SECTION_H (nn).sh_type == SHT_NULL
950 || NEW_SECTION_H (nn).sh_type == SHT_NOBITS)
953 /* Write out the sections. .data and .data1 (and data2, called
954 ".data" in the strings table) get copied from the current process
955 instead of the old file. */
956 if (!strcmp (old_section_names + NEW_SECTION_H (n).sh_name, ".data")
957 || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name),
959 /* Taking these sections from the current process, breaks
960 Linux in a subtle way. Binaries only run on the
961 architecture (e.g. i586 vs i686) of the dumping machine */
963 || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name),
965 || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name),
967 || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name),
970 || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name),
972 || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name),
974 src = (caddr_t) OLD_SECTION_H (n).sh_addr;
976 src = old_base + OLD_SECTION_H (n).sh_offset;
978 memcpy (NEW_SECTION_H (nn).sh_offset + new_base, src,
979 NEW_SECTION_H (nn).sh_size);
982 /* Update Alpha COFF symbol table: */
983 if (strcmp (old_section_names + OLD_SECTION_H (n).sh_name, ".mdebug")
986 pHDRR symhdr = (pHDRR) (NEW_SECTION_H (nn).sh_offset + new_base);
988 symhdr->cbLineOffset += new_data2_size;
989 symhdr->cbDnOffset += new_data2_size;
990 symhdr->cbPdOffset += new_data2_size;
991 symhdr->cbSymOffset += new_data2_size;
992 symhdr->cbOptOffset += new_data2_size;
993 symhdr->cbAuxOffset += new_data2_size;
994 symhdr->cbSsOffset += new_data2_size;
995 symhdr->cbSsExtOffset += new_data2_size;
996 symhdr->cbFdOffset += new_data2_size;
997 symhdr->cbRfdOffset += new_data2_size;
998 symhdr->cbExtOffset += new_data2_size;
1000 #endif /* __alpha__ */
1002 #if defined (__sony_news) && defined (_SYSTYPE_SYSV)
1003 if (NEW_SECTION_H (nn).sh_type == SHT_MIPS_DEBUG && old_mdebug_index)
1005 int diff = NEW_SECTION_H(nn).sh_offset
1006 - OLD_SECTION_H(old_mdebug_index).sh_offset;
1007 HDRR *phdr = (HDRR *)(NEW_SECTION_H (nn).sh_offset + new_base);
1011 phdr->cbLineOffset += diff;
1012 phdr->cbDnOffset += diff;
1013 phdr->cbPdOffset += diff;
1014 phdr->cbSymOffset += diff;
1015 phdr->cbOptOffset += diff;
1016 phdr->cbAuxOffset += diff;
1017 phdr->cbSsOffset += diff;
1018 phdr->cbSsExtOffset += diff;
1019 phdr->cbFdOffset += diff;
1020 phdr->cbRfdOffset += diff;
1021 phdr->cbExtOffset += diff;
1024 #endif /* __sony_news && _SYSTYPE_SYSV */
1027 /* Adjust the HDRR offsets in .mdebug and copy the
1028 line data if it's in its usual 'hole' in the object.
1029 Makes the new file debuggable with dbx.
1030 patches up two problems: the absolute file offsets
1031 in the HDRR record of .mdebug (see /usr/include/syms.h), and
1032 the ld bug that gets the line table in a hole in the
1033 elf file rather than in the .mdebug section proper.
1034 David Anderson. davea@sgi.com Jan 16,1994. */
1035 if (n == old_mdebug_index)
1037 #define MDEBUGADJUST(__ct,__fileaddr) \
1038 if (n_phdrr->__ct > 0) \
1040 n_phdrr->__fileaddr += movement; \
1043 HDRR * o_phdrr = (HDRR *)((byte *)old_base + OLD_SECTION_H (n).sh_offset);
1044 HDRR * n_phdrr = (HDRR *)((byte *)new_base + NEW_SECTION_H (nn).sh_offset);
1045 unsigned movement = new_data2_size;
1047 MDEBUGADJUST (idnMax, cbDnOffset);
1048 MDEBUGADJUST (ipdMax, cbPdOffset);
1049 MDEBUGADJUST (isymMax, cbSymOffset);
1050 MDEBUGADJUST (ioptMax, cbOptOffset);
1051 MDEBUGADJUST (iauxMax, cbAuxOffset);
1052 MDEBUGADJUST (issMax, cbSsOffset);
1053 MDEBUGADJUST (issExtMax, cbSsExtOffset);
1054 MDEBUGADJUST (ifdMax, cbFdOffset);
1055 MDEBUGADJUST (crfd, cbRfdOffset);
1056 MDEBUGADJUST (iextMax, cbExtOffset);
1057 /* The Line Section, being possible off in a hole of the object,
1058 requires special handling. */
1059 if (n_phdrr->cbLine > 0)
1061 if (o_phdrr->cbLineOffset > (OLD_SECTION_H (n).sh_offset
1062 + OLD_SECTION_H (n).sh_size))
1064 /* line data is in a hole in elf. do special copy and adjust
1065 for this ld mistake.
1067 n_phdrr->cbLineOffset += movement;
1069 memcpy (n_phdrr->cbLineOffset + new_base,
1070 o_phdrr->cbLineOffset + old_base, n_phdrr->cbLine);
1074 /* somehow line data is in .mdebug as it is supposed to be. */
1075 MDEBUGADJUST (cbLine, cbLineOffset);
1081 /* If it is the symbol table, its st_shndx field needs to be patched. */
1082 if (NEW_SECTION_H (nn).sh_type == SHT_SYMTAB
1083 || NEW_SECTION_H (nn).sh_type == SHT_DYNSYM)
1085 ElfW(Shdr) *spt = &NEW_SECTION_H (nn);
1086 unsigned int num = spt->sh_size / spt->sh_entsize;
1087 ElfW(Sym) * sym = (ElfW(Sym) *) (NEW_SECTION_H (nn).sh_offset +
1089 for (; num--; sym++)
1091 if ((sym->st_shndx == SHN_UNDEF)
1092 || (sym->st_shndx == SHN_ABS)
1093 || (sym->st_shndx == SHN_COMMON))
1096 PATCH_INDEX (sym->st_shndx);
1101 /* Update the symbol values of _edata and _end. */
1102 for (n = new_file_h->e_shnum - 1; n; n--)
1105 ElfW(Sym) *symp, *symendp;
1107 if (NEW_SECTION_H (n).sh_type != SHT_DYNSYM
1108 && NEW_SECTION_H (n).sh_type != SHT_SYMTAB)
1111 symnames = ((byte *) new_base
1112 + NEW_SECTION_H (NEW_SECTION_H (n).sh_link).sh_offset);
1113 symp = (ElfW(Sym) *) (NEW_SECTION_H (n).sh_offset + new_base);
1114 symendp = (ElfW(Sym) *) ((byte *)symp + NEW_SECTION_H (n).sh_size);
1116 for (; symp < symendp; symp ++)
1117 if (strcmp ((char *) (symnames + symp->st_name), "_end") == 0
1118 || strcmp ((char *) (symnames + symp->st_name), "end") == 0
1119 || strcmp ((char *) (symnames + symp->st_name), "_edata") == 0
1120 || strcmp ((char *) (symnames + symp->st_name), "edata") == 0)
1121 memcpy (&symp->st_value, &new_bss_addr, sizeof (new_bss_addr));
1124 /* This loop seeks out relocation sections for the data section, so
1125 that it can undo relocations performed by the runtime linker. */
1126 for (n = new_file_h->e_shnum - 1; n; n--)
1128 ElfW(Shdr) section = NEW_SECTION_H (n);
1129 switch (section.sh_type) {
1134 /* This code handles two different size structs, but there should
1135 be no harm in that provided that r_offset is always the first
1137 nn = section.sh_info;
1138 if (!strcmp (old_section_names + NEW_SECTION_H (nn).sh_name, ".data")
1139 || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name),
1142 || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name),
1144 || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name),
1146 || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name),
1149 || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name),
1151 || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name),
1154 ElfW(Addr) offset = NEW_SECTION_H (nn).sh_addr -
1155 NEW_SECTION_H (nn).sh_offset;
1156 caddr_t reloc = old_base + section.sh_offset, end;
1157 for (end = reloc + section.sh_size; reloc < end;
1158 reloc += section.sh_entsize)
1160 ElfW(Addr) addr = ((ElfW(Rel) *) reloc)->r_offset - offset;
1162 /* The Alpha ELF binutils currently have a bug that
1163 sometimes results in relocs that contain all
1164 zeroes. Work around this for now... */
1165 if (((ElfW(Rel) *) reloc)->r_offset == 0)
1168 memcpy (new_base + addr, old_base + addr, sizeof(ElfW(Addr)));
1175 #ifdef UNEXEC_USE_MAP_PRIVATE
1176 if (lseek (new_file, 0, SEEK_SET) == -1)
1177 fatal ("Can't rewind (%s): errno %d\n", new_name, errno);
1179 if (write (new_file, new_base, new_file_size) != new_file_size)
1180 fatal ("Can't write (%s): errno %d\n", new_name, errno);
1183 /* Close the files and make the new file executable. */
1185 if (close (old_file))
1186 fatal ("Can't close (%s): errno %d\n", old_name, errno);
1188 if (close (new_file))
1189 fatal ("Can't close (%s): errno %d\n", new_name, errno);
1191 if (stat (new_name, &stat_buf) == -1)
1192 fatal ("Can't stat (%s): errno %d\n", new_name, errno);
1196 stat_buf.st_mode |= 0111 & ~n;
1197 if (chmod (new_name, stat_buf.st_mode) == -1)
1198 fatal ("Can't chmod (%s): errno %d\n", new_name, errno);