1 /* Copyright (C) 1985,86,87,88,92,93,94 Free Software Foundation, Inc.
3 This file is part of GNU Emacs.
5 GNU Emacs is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2, or (at your option)
10 GNU Emacs is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with GNU Emacs; see the file COPYING. If not, write to
17 the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA. */
22 * unexec.c - Convert a running program into an a.out file.
24 * Author: Spencer W. Thomas
25 * Computer Science Dept.
27 * Date: Tue Mar 2 1982
28 * Modified heavily since then.
31 * unexec (new_name, a_name, data_start, bss_start, entry_address)
32 * char *new_name, *a_name;
33 * unsigned data_start, bss_start, entry_address;
35 * Takes a snapshot of the program and makes an a.out format file in the
36 * file named by the string argument new_name.
37 * If a_name is non-NULL, the symbol table will be taken from the given file.
38 * On some machines, an existing a_name file is required.
40 * The boundaries within the a.out file may be adjusted with the data_start
41 * and bss_start arguments. Either or both may be given as 0 for defaults.
43 * Data_start gives the boundary between the text segment and the data
44 * segment of the program. The text segment can contain shared, read-only
45 * program code and literal data, while the data segment is always unshared
46 * and unprotected. Data_start gives the lowest unprotected address.
47 * The value you specify may be rounded down to a suitable boundary
48 * as required by the machine you are using.
50 * Specifying zero for data_start means the boundary between text and data
51 * should not be the same as when the program was loaded.
52 * If NO_REMAP is defined, the argument data_start is ignored and the
53 * segment boundaries are never changed.
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.
64 * If you make improvements I'd like to get them too.
65 * harpo!utah-cs!thomas, thomas@Utah-20
69 /* Modified to support SysVr3 shared libraries by James Van Artsdalen
70 * of Dell Computer Corporation. james@bigtex.cactus.org.
73 /* There are several compilation parameters affecting unexec:
77 Define this if your system uses COFF for executables.
81 Define this if you are using the GNU coff encapsulated a.out format.
82 This is closer to a.out than COFF. You should *not* define COFF if
83 you define COFF_ENCAPSULATE
85 Otherwise we assume you use Berkeley format.
89 Define this if you do not want to try to save Emacs's pure data areas
90 as part of the text segment.
92 Saving them as text is good because it allows users to share more.
94 However, on machines that locate the text area far from the data area,
95 the boundary cannot feasibly be moved. Such machines require
98 Also, remapping can cause trouble with the built-in startup routine
99 /lib/crt0.o, which defines `environ' as an initialized variable.
100 Dumping `environ' as pure does not work! So, to use remapping,
101 you must write a startup routine for your machine in Emacs's crt0.c.
102 If NO_REMAP is defined, Emacs uses the system's crt0.o.
106 Some machines that use COFF executables require that each section
107 start on a certain boundary *in the COFF file*. Such machines should
108 define SECTION_ALIGNMENT to a mask of the low-order bits that must be
109 zero on such a boundary. This mask is used to control padding between
110 segments in the COFF file.
112 If SECTION_ALIGNMENT is not defined, the segments are written
113 consecutively with no attempt at alignment. This is right for
118 Some machines require that the beginnings and ends of segments
119 *in core* be on certain boundaries. For most machines, a page
120 boundary is sufficient. That is the default. When a larger
121 boundary is needed, define SEGMENT_MASK to a mask of
122 the bits that must be zero on such a boundary.
126 Some machines count the a.out header as part of the size of the text
127 segment (a_text); they may actually load the header into core as the
128 first data in the text segment. Some have additional padding between
129 the header and the real text of the program that is counted in a_text.
131 For these machines, define A_TEXT_OFFSET(HDR) to examine the header
132 structure HDR and return the number of bytes to add to `a_text'
133 before writing it (above and beyond the number of bytes of actual
134 program text). HDR's standard fields are already correct, except that
135 this adjustment to the `a_text' field has not yet been made;
136 thus, the amount of offset can depend on the data in the file.
140 If defined, this macro specifies the number of bytes to seek into the
141 a.out file before starting to write the text segment.
145 For machines using COFF, this macro, if defined, is a value stored
146 into the magic number field of the output file.
150 This macro can be used to generate statements to adjust or
151 initialize nonstandard fields in the file header
155 Macro to correct an int which is the bit pattern of a pointer to a byte
156 into an int which is the number of a byte.
158 This macro has a default definition which is usually right.
159 This default definition is a no-op on most machines (where a
160 pointer looks like an int) but not on all machines.
165 #define PERROR(arg) perror (arg); return -1
169 #define PERROR(file) report_error (file, new)
172 #ifndef CANNOT_DUMP /* all rest of file! */
174 #if defined(COFF) && defined(HAVE_COFF_H)
178 #include <fcntl.h> /* for O_RDONLY, O_RDWR */
179 #include <crt0.h> /* for _crt0_startup_flags and its bits */
180 static int save_djgpp_startup_flags
;
181 #endif /* __DJGPP__ > 1 */
182 #define filehdr external_filehdr
183 #define scnhdr external_scnhdr
184 #define syment external_syment
185 #define auxent external_auxent
186 #define n_numaux e_numaux
187 #define n_type e_type
190 unsigned short magic
; /* type of file */
191 unsigned short vstamp
; /* version stamp */
192 unsigned long tsize
; /* text size in bytes, padded to FW bdry*/
193 unsigned long dsize
; /* initialized data " " */
194 unsigned long bsize
; /* uninitialized data " " */
195 unsigned long entry
; /* entry pt. */
196 unsigned long text_start
;/* base of text used for this file */
197 unsigned long data_start
;/* base of data used for this file */
199 #endif /* not MSDOS */
201 #ifdef COFF_ENCAPSULATE
202 int need_coff_header
= 1;
203 #include <coff-encap/a.out.encap.h> /* The location might be a poor assumption */
204 #else /* not COFF_ENCAPSULATE */
206 #endif /* not COFF_ENCAPSULATE */
207 #endif /* not COFF */
209 /* Define getpagesize if the system does not.
210 Note that this may depend on symbols defined in a.out.h. */
211 #include "getpagesize.h"
213 #ifndef makedev /* Try to detect types.h already loaded */
214 #include <sys/types.h>
217 #include <sys/stat.h>
220 #include <sys/file.h> /* Must be after sys/types.h for USG and BSD4_1*/
234 extern char *start_of_text (); /* Start of text */
235 extern char *start_of_data (); /* Start of initialized data */
238 static long block_copy_start
; /* Old executable start point */
239 static struct filehdr f_hdr
; /* File header */
240 static struct aouthdr f_ohdr
; /* Optional file header (a.out) */
241 long bias
; /* Bias to add for growth */
242 long lnnoptr
; /* Pointer to line-number info within file */
243 #define SYMS_START block_copy_start
245 static long text_scnptr
;
246 static long data_scnptr
;
248 static long coff_offset
;
253 extern void *sbrk ();
256 /* Some systems with __STDC__ compilers still declare this `char *' in some
257 header file, and our declaration conflicts. The return value is always
258 cast, so it should be harmless to leave it undefined. Hopefully
259 machines with different size pointers and ints declare sbrk in a header
262 extern void *sbrk ();
264 extern char *sbrk ();
265 #endif /* __STDC__ */
269 #define SYMS_START ((long) N_SYMOFF (ohdr))
271 /* Some machines override the structure name for an a.out header. */
272 #ifndef EXEC_HDR_TYPE
273 #define EXEC_HDR_TYPE struct exec
278 #define MY_ID HP9000S200_ID
282 #endif /* no HP9000S200_ID */
283 static MAGIC OLDMAGIC
= {MY_ID
, SHARE_MAGIC
};
284 static MAGIC NEWMAGIC
= {MY_ID
, DEMAND_MAGIC
};
285 #define N_TXTOFF(x) TEXT_OFFSET(x)
286 #define N_SYMOFF(x) LESYM_OFFSET(x)
287 static EXEC_HDR_TYPE hdr
, ohdr
;
291 #if defined (USG) && !defined (IBMAIX) && !defined (IRIS) && !defined (COFF_ENCAPSULATE) && !defined (GNU_LINUX)
292 static struct bhdr hdr
, ohdr
;
293 #define a_magic fmagic
298 #define a_trsize rtsize
299 #define a_drsize rdsize
300 #define a_entry entry
301 #define N_BADMAG(x) \
302 (((x).fmagic)!=OMAGIC && ((x).fmagic)!=NMAGIC &&\
303 ((x).fmagic)!=FMAGIC && ((x).fmagic)!=IMAGIC)
304 #define NEWMAGIC FMAGIC
305 #else /* IRIS or IBMAIX or not USG */
306 static EXEC_HDR_TYPE hdr
, ohdr
;
307 #define NEWMAGIC ZMAGIC
308 #endif /* IRIS or IBMAIX not USG */
309 #endif /* not HPUX */
311 static int unexec_text_start
;
312 static int unexec_data_start
;
314 #ifdef COFF_ENCAPSULATE
315 /* coffheader is defined in the GNU a.out.encap.h file. */
316 struct coffheader coffheader
;
319 #endif /* not COFF */
323 /* Correct an int which is the bit pattern of a pointer to a byte
324 into an int which is the number of a byte.
325 This is a no-op on ordinary machines, but not on all. */
327 #ifndef ADDR_CORRECT /* Let m-*.h files override this definition */
328 #define ADDR_CORRECT(x) ((char *)(x) - (char*)0)
336 report_error (file
, fd
)
342 report_file_error ("Cannot unexec", Fcons (build_string (file
), Qnil
));
346 #define ERROR0(msg) report_error_1 (new, msg, 0, 0); return -1
347 #define ERROR1(msg,x) report_error_1 (new, msg, x, 0); return -1
348 #define ERROR2(msg,x,y) report_error_1 (new, msg, x, y); return -1
351 report_error_1 (fd
, msg
, a1
, a2
)
360 fprintf (stderr
, msg
, a1
, a2
);
361 fprintf (stderr
, "\n");
365 static int make_hdr ();
366 static int copy_text_and_data ();
367 static int copy_sym ();
368 static void mark_x ();
370 /* ****************************************************************
373 * Make the header in the new a.out from the header in core.
374 * Modify the text and data sizes.
377 make_hdr (new, a_out
, data_start
, bss_start
, entry_address
, a_name
, new_name
)
379 unsigned data_start
, bss_start
, entry_address
;
385 auto struct scnhdr f_thdr
; /* Text section header */
386 auto struct scnhdr f_dhdr
; /* Data section header */
387 auto struct scnhdr f_bhdr
; /* Bss section header */
388 auto struct scnhdr scntemp
; /* Temporary section header */
391 #ifdef USG_SHARED_LIBRARIES
392 extern unsigned int bss_end
;
394 unsigned int bss_end
;
397 pagemask
= getpagesize () - 1;
399 /* Adjust text/data boundary. */
401 data_start
= (int) start_of_data ();
402 #else /* not NO_REMAP */
404 data_start
= (int) start_of_data ();
405 #endif /* not NO_REMAP */
406 data_start
= ADDR_CORRECT (data_start
);
409 data_start
= data_start
& ~SEGMENT_MASK
; /* (Down) to segment boundary. */
411 data_start
= data_start
& ~pagemask
; /* (Down) to page boundary. */
414 bss_end
= ADDR_CORRECT (sbrk (0)) + pagemask
;
415 bss_end
&= ~ pagemask
;
417 /* Adjust data/bss boundary. */
420 bss_start
= (ADDR_CORRECT (bss_start
) + pagemask
);
421 /* (Up) to page bdry. */
422 bss_start
&= ~ pagemask
;
423 if (bss_start
> bss_end
)
425 ERROR1 ("unexec: Specified bss_start (%u) is past end of program",
432 if (data_start
> bss_start
) /* Can't have negative data size. */
434 ERROR2 ("unexec: data_start (%u) can't be greater than bss_start (%u)",
435 data_start
, bss_start
);
439 coff_offset
= 0L; /* stays zero, except in DJGPP */
441 /* Salvage as much info from the existing file as possible */
446 /* Support the coff-go32-exe format with a prepended stub, since
447 this is what GCC 2.8.0 and later generates by default in DJGPP. */
448 unsigned short mz_header
[3];
450 if (read (a_out
, &mz_header
, sizeof (mz_header
)) != sizeof (mz_header
))
454 if (mz_header
[0] == 0x5a4d || mz_header
[0] == 0x4d5a) /* "MZ" or "ZM" */
456 coff_offset
= (long)mz_header
[2] * 512L;
458 coff_offset
+= (long)mz_header
[1] - 512L;
459 lseek (a_out
, coff_offset
, 0);
462 lseek (a_out
, 0L, 0);
463 #endif /* __DJGPP__ > 1 */
465 if (read (a_out
, &f_hdr
, sizeof (f_hdr
)) != sizeof (f_hdr
))
469 block_copy_start
+= sizeof (f_hdr
);
470 if (f_hdr
.f_opthdr
> 0)
472 if (read (a_out
, &f_ohdr
, sizeof (f_ohdr
)) != sizeof (f_ohdr
))
476 block_copy_start
+= sizeof (f_ohdr
);
478 /* Loop through section headers, copying them in */
479 lseek (a_out
, coff_offset
+ sizeof (f_hdr
) + f_hdr
.f_opthdr
, 0);
480 for (scns
= f_hdr
.f_nscns
; scns
> 0; scns
--) {
481 if (read (a_out
, &scntemp
, sizeof (scntemp
)) != sizeof (scntemp
))
485 if (scntemp
.s_scnptr
> 0L)
487 if (block_copy_start
< scntemp
.s_scnptr
+ scntemp
.s_size
)
488 block_copy_start
= scntemp
.s_scnptr
+ scntemp
.s_size
;
490 if (strcmp (scntemp
.s_name
, ".text") == 0)
494 else if (strcmp (scntemp
.s_name
, ".data") == 0)
498 else if (strcmp (scntemp
.s_name
, ".bss") == 0)
506 ERROR0 ("can't build a COFF file from scratch yet");
509 /* Now we alter the contents of all the f_*hdr variables
510 to correspond to what we want to dump. */
512 #ifdef USG_SHARED_LIBRARIES
514 /* The amount of data we're adding to the file is distance from the
515 * end of the original .data space to the current end of the .data
519 bias
= bss_start
- (f_ohdr
.data_start
+ f_dhdr
.s_size
);
523 f_hdr
.f_flags
|= (F_RELFLG
| F_EXEC
);
528 f_ohdr
.magic
= EXEC_MAGIC
;
531 f_ohdr
.text_start
= (long) start_of_text ();
532 f_ohdr
.tsize
= data_start
- f_ohdr
.text_start
;
533 f_ohdr
.data_start
= data_start
;
534 #endif /* NO_REMAP */
535 f_ohdr
.dsize
= bss_start
- f_ohdr
.data_start
;
536 f_ohdr
.bsize
= bss_end
- bss_start
;
537 #ifndef KEEP_OLD_TEXT_SCNPTR
538 /* On some machines, the old values are right.
539 ??? Maybe on all machines with NO_REMAP. */
540 f_thdr
.s_size
= f_ohdr
.tsize
;
541 f_thdr
.s_scnptr
= sizeof (f_hdr
) + sizeof (f_ohdr
);
542 f_thdr
.s_scnptr
+= (f_hdr
.f_nscns
) * (sizeof (f_thdr
));
543 #endif /* KEEP_OLD_TEXT_SCNPTR */
544 #ifdef ADJUST_TEXT_SCNHDR_SIZE
545 /* On some machines, `text size' includes all headers. */
546 f_thdr
.s_size
-= f_thdr
.s_scnptr
;
547 #endif /* ADJUST_TEST_SCNHDR_SIZE */
548 lnnoptr
= f_thdr
.s_lnnoptr
;
549 #ifdef SECTION_ALIGNMENT
550 /* Some systems require special alignment
551 of the sections in the file itself. */
553 = (f_thdr
.s_scnptr
+ SECTION_ALIGNMENT
) & ~SECTION_ALIGNMENT
;
554 #endif /* SECTION_ALIGNMENT */
556 f_thdr
.s_scnptr
= 0xd0;
558 text_scnptr
= f_thdr
.s_scnptr
;
559 #ifdef ADJUST_TEXTBASE
560 text_scnptr
= sizeof (f_hdr
) + sizeof (f_ohdr
) + (f_hdr
.f_nscns
) * (sizeof (f_thdr
));
562 #ifndef KEEP_OLD_PADDR
563 f_dhdr
.s_paddr
= f_ohdr
.data_start
;
564 #endif /* KEEP_OLD_PADDR */
565 f_dhdr
.s_vaddr
= f_ohdr
.data_start
;
566 f_dhdr
.s_size
= f_ohdr
.dsize
;
567 f_dhdr
.s_scnptr
= f_thdr
.s_scnptr
+ f_thdr
.s_size
;
568 #ifdef SECTION_ALIGNMENT
569 /* Some systems require special alignment
570 of the sections in the file itself. */
572 = (f_dhdr
.s_scnptr
+ SECTION_ALIGNMENT
) & ~SECTION_ALIGNMENT
;
573 #endif /* SECTION_ALIGNMENT */
574 #ifdef DATA_SECTION_ALIGNMENT
575 /* Some systems require special alignment
576 of the data section only. */
578 = (f_dhdr
.s_scnptr
+ DATA_SECTION_ALIGNMENT
) & ~DATA_SECTION_ALIGNMENT
;
579 #endif /* DATA_SECTION_ALIGNMENT */
580 data_scnptr
= f_dhdr
.s_scnptr
;
581 #ifndef KEEP_OLD_PADDR
582 f_bhdr
.s_paddr
= f_ohdr
.data_start
+ f_ohdr
.dsize
;
583 #endif /* KEEP_OLD_PADDR */
584 f_bhdr
.s_vaddr
= f_ohdr
.data_start
+ f_ohdr
.dsize
;
585 f_bhdr
.s_size
= f_ohdr
.bsize
;
586 f_bhdr
.s_scnptr
= 0L;
587 #ifndef USG_SHARED_LIBRARIES
588 bias
= f_dhdr
.s_scnptr
+ f_dhdr
.s_size
- block_copy_start
;
591 if (f_hdr
.f_symptr
> 0L)
593 f_hdr
.f_symptr
+= bias
;
596 if (f_thdr
.s_lnnoptr
> 0L)
598 f_thdr
.s_lnnoptr
+= bias
;
601 #ifdef ADJUST_EXEC_HEADER
603 #endif /* ADJUST_EXEC_HEADER */
605 if (write (new, &f_hdr
, sizeof (f_hdr
)) != sizeof (f_hdr
))
610 if (write (new, &f_ohdr
, sizeof (f_ohdr
)) != sizeof (f_ohdr
))
615 #ifndef USG_SHARED_LIBRARIES
617 if (write (new, &f_thdr
, sizeof (f_thdr
)) != sizeof (f_thdr
))
622 if (write (new, &f_dhdr
, sizeof (f_dhdr
)) != sizeof (f_dhdr
))
627 if (write (new, &f_bhdr
, sizeof (f_bhdr
)) != sizeof (f_bhdr
))
632 #else /* USG_SHARED_LIBRARIES */
634 /* The purpose of this code is to write out the new file's section
637 * Scan through the original file's sections. If the encountered
638 * section is one we know (.text, .data or .bss), write out the
639 * correct header. If it is a section we do not know (such as
640 * .lib), adjust the address of where the section data is in the
641 * file, and write out the header.
643 * If any section precedes .text or .data in the file, this code
644 * will not adjust the file pointer for that section correctly.
647 /* This used to use sizeof (f_ohdr) instead of .f_opthdr.
648 .f_opthdr is said to be right when there is no optional header. */
649 lseek (a_out
, sizeof (f_hdr
) + f_hdr
.f_opthdr
, 0);
651 for (scns
= f_hdr
.f_nscns
; scns
> 0; scns
--)
653 if (read (a_out
, &scntemp
, sizeof (scntemp
)) != sizeof (scntemp
))
656 if (!strcmp (scntemp
.s_name
, f_thdr
.s_name
)) /* .text */
658 if (write (new, &f_thdr
, sizeof (f_thdr
)) != sizeof (f_thdr
))
661 else if (!strcmp (scntemp
.s_name
, f_dhdr
.s_name
)) /* .data */
663 if (write (new, &f_dhdr
, sizeof (f_dhdr
)) != sizeof (f_dhdr
))
666 else if (!strcmp (scntemp
.s_name
, f_bhdr
.s_name
)) /* .bss */
668 if (write (new, &f_bhdr
, sizeof (f_bhdr
)) != sizeof (f_bhdr
))
673 if (scntemp
.s_scnptr
)
674 scntemp
.s_scnptr
+= bias
;
675 if (write (new, &scntemp
, sizeof (scntemp
)) != sizeof (scntemp
))
679 #endif /* USG_SHARED_LIBRARIES */
683 #else /* if not COFF */
685 /* Get symbol table info from header of a.out file if given one. */
688 #ifdef COFF_ENCAPSULATE
689 if (read (a_out
, &coffheader
, sizeof coffheader
) != sizeof coffheader
)
693 if (coffheader
.f_magic
!= COFF_MAGIC
)
695 ERROR1("%s doesn't have legal coff magic number\n", a_name
);
698 if (read (a_out
, &ohdr
, sizeof hdr
) != sizeof hdr
)
705 ERROR1 ("invalid magic number in %s", a_name
);
711 #ifdef COFF_ENCAPSULATE
712 /* We probably could without too much trouble. The code is in gld
713 * but I don't have that much time or incentive.
715 ERROR0 ("can't build a COFF file from scratch yet");
717 #ifdef MSDOS /* Demacs 1.1.1 91/10/16 HIRANO Satoshi */
718 bzero ((void *)&hdr
, sizeof hdr
);
720 bzero (&hdr
, sizeof hdr
);
725 unexec_text_start
= (long) start_of_text ();
726 unexec_data_start
= data_start
;
728 /* Machine-dependent fixup for header, or maybe for unexec_text_start */
729 #ifdef ADJUST_EXEC_HEADER
731 #endif /* ADJUST_EXEC_HEADER */
735 if (entry_address
!= 0)
736 hdr
.a_entry
= entry_address
;
738 hdr
.a_bss
= bss_end
- bss_start
;
739 hdr
.a_data
= bss_start
- data_start
;
741 hdr
.a_text
= ohdr
.a_text
;
742 #else /* not NO_REMAP */
743 hdr
.a_text
= data_start
- unexec_text_start
;
746 hdr
.a_text
+= A_TEXT_OFFSET (ohdr
);
749 #endif /* not NO_REMAP */
751 #ifdef COFF_ENCAPSULATE
752 /* We are encapsulating BSD format within COFF format. */
754 struct coffscn
*tp
, *dp
, *bp
;
755 tp
= &coffheader
.scns
[0];
756 dp
= &coffheader
.scns
[1];
757 bp
= &coffheader
.scns
[2];
758 tp
->s_size
= hdr
.a_text
+ sizeof(struct exec
);
759 dp
->s_paddr
= data_start
;
760 dp
->s_vaddr
= data_start
;
761 dp
->s_size
= hdr
.a_data
;
762 bp
->s_paddr
= dp
->s_vaddr
+ dp
->s_size
;
763 bp
->s_vaddr
= bp
->s_paddr
;
764 bp
->s_size
= hdr
.a_bss
;
765 coffheader
.tsize
= tp
->s_size
;
766 coffheader
.dsize
= dp
->s_size
;
767 coffheader
.bsize
= bp
->s_size
;
768 coffheader
.text_start
= tp
->s_vaddr
;
769 coffheader
.data_start
= dp
->s_vaddr
;
771 if (write (new, &coffheader
, sizeof coffheader
) != sizeof coffheader
)
775 #endif /* COFF_ENCAPSULATE */
777 if (write (new, &hdr
, sizeof hdr
) != sizeof hdr
)
782 #if 0 /* This #ifndef caused a bug on GNU/Linux when using QMAGIC. */
783 /* This adjustment was done above only #ifndef NO_REMAP,
784 so only undo it now #ifndef NO_REMAP. */
785 /* #ifndef NO_REMAP */
788 hdr
.a_text
-= A_TEXT_OFFSET (ohdr
);
793 #endif /* not COFF */
796 write_segment (new, ptr
, end
)
798 register char *ptr
, *end
;
800 register int i
, nwrite
, ret
;
805 /* This is the normal amount to write at once.
806 It is the size of block that NFS uses. */
807 int writesize
= 1 << 13;
808 int pagesize
= getpagesize ();
811 bzero (zeros
, sizeof (zeros
));
813 for (i
= 0; ptr
< end
;)
815 /* Distance to next multiple of writesize. */
816 nwrite
= (((int) ptr
+ writesize
) & -writesize
) - (int) ptr
;
817 /* But not beyond specified end. */
818 if (nwrite
> end
- ptr
) nwrite
= end
- ptr
;
819 ret
= write (new, ptr
, nwrite
);
820 /* If write gets a page fault, it means we reached
821 a gap between the old text segment and the old data segment.
822 This gap has probably been remapped into part of the text segment.
823 So write zeros for it. */
830 /* Write only a page of zeros at once,
831 so that we we don't overshoot the start
832 of the valid memory in the old data segment. */
833 if (nwrite
> pagesize
)
835 write (new, zeros
, nwrite
);
837 #if 0 /* Now that we have can ask `write' to write more than a page,
838 it is legit for write do less than the whole amount specified. */
839 else if (nwrite
!= ret
)
842 "unexec write failure: addr 0x%x, fileno %d, size 0x%x, wrote 0x%x, errno %d",
843 ptr
, new, nwrite
, ret
, errno
);
851 /* ****************************************************************
854 * Copy the text and data segments from memory to the new a.out
857 copy_text_and_data (new, a_out
)
865 #ifdef USG_SHARED_LIBRARIES
868 struct scnhdr scntemp
; /* Temporary section header */
870 /* The purpose of this code is to write out the new file's section
873 * Step through the section table. If we know the section (.text,
874 * .data) do the appropriate thing. Otherwise, if the section has
875 * no allocated space in the file (.bss), do nothing. Otherwise,
876 * the section has space allocated in the file, and is not a section
877 * we know. So just copy it.
880 lseek (a_out
, sizeof (struct filehdr
) + sizeof (struct aouthdr
), 0);
882 for (scns
= f_hdr
.f_nscns
; scns
> 0; scns
--)
884 if (read (a_out
, &scntemp
, sizeof (scntemp
)) != sizeof (scntemp
))
887 if (!strcmp (scntemp
.s_name
, ".text"))
889 lseek (new, (long) text_scnptr
, 0);
890 ptr
= (char *) f_ohdr
.text_start
;
891 end
= ptr
+ f_ohdr
.tsize
;
892 write_segment (new, ptr
, end
);
894 else if (!strcmp (scntemp
.s_name
, ".data"))
896 lseek (new, (long) data_scnptr
, 0);
897 ptr
= (char *) f_ohdr
.data_start
;
898 end
= ptr
+ f_ohdr
.dsize
;
899 write_segment (new, ptr
, end
);
901 else if (!scntemp
.s_scnptr
)
902 ; /* do nothing - no data for this section */
907 long old_a_out_ptr
= lseek (a_out
, 0, 1);
909 lseek (a_out
, scntemp
.s_scnptr
, 0);
910 for (size
= scntemp
.s_size
; size
> 0; size
-= sizeof (page
))
912 n
= size
> sizeof (page
) ? sizeof (page
) : size
;
913 if (read (a_out
, page
, n
) != n
|| write (new, page
, n
) != n
)
916 lseek (a_out
, old_a_out_ptr
, 0);
920 #else /* COFF, but not USG_SHARED_LIBRARIES */
924 /* Dump the original table of exception handlers, not the one
925 where our exception hooks are registered. */
926 __djgpp_exception_toggle ();
928 /* Switch off startup flags that might have been set at runtime
929 and which might change the way that dumped Emacs works. */
930 save_djgpp_startup_flags
= _crt0_startup_flags
;
931 _crt0_startup_flags
&= ~(_CRT0_FLAG_NO_LFN
| _CRT0_FLAG_NEARPTR
);
935 lseek (new, (long) text_scnptr
, 0);
936 ptr
= (char *) f_ohdr
.text_start
;
937 #ifdef HEADER_INCL_IN_TEXT
938 /* For Gould UTX/32, text starts after headers */
939 ptr
= (char *) (ptr
+ text_scnptr
);
940 #endif /* HEADER_INCL_IN_TEXT */
941 end
= ptr
+ f_ohdr
.tsize
;
942 write_segment (new, ptr
, end
);
944 lseek (new, (long) data_scnptr
, 0);
945 ptr
= (char *) f_ohdr
.data_start
;
946 end
= ptr
+ f_ohdr
.dsize
;
947 write_segment (new, ptr
, end
);
951 /* Restore our exception hooks. */
952 __djgpp_exception_toggle ();
954 /* Restore the startup flags. */
955 _crt0_startup_flags
= save_djgpp_startup_flags
;
959 #endif /* USG_SHARED_LIBRARIES */
961 #else /* if not COFF */
963 /* Some machines count the header as part of the text segment.
964 That is to say, the header appears in core
965 just before the address that start_of_text returns.
966 For them, N_TXTOFF is the place where the header goes.
967 We must adjust the seek to the place after the header.
968 Note that at this point hdr.a_text does *not* count
969 the extra A_TEXT_OFFSET bytes, only the actual bytes of code. */
972 lseek (new, (long) A_TEXT_SEEK (hdr
), 0);
974 lseek (new, (long) N_TXTOFF (hdr
), 0);
975 #endif /* no A_TEXT_SEEK */
979 /* Acorn's RISC-iX has a wacky way of initialising the position of the heap.
980 * There is a little table in crt0.o that is filled at link time with
981 * the min and current brk positions, among other things. When start
982 * runs, it copies the table to where these parameters live during
983 * execution. This data is in text space, so it cannot be modified here
984 * before saving the executable, so the data is written manually. In
985 * addition, the table does not have a label, and the nearest accessible
986 * label (mcount) is not prefixed with a '_', thus making it inaccessible
987 * from within C programs. To overcome this, emacs's executable is passed
988 * through the command 'nm %s | fgrep mcount' into a pipe, and the
989 * resultant output is then used to find the address of 'mcount'. As far as
990 * is possible to determine, in RISC-iX releases prior to 1.2, the negative
991 * offset of the table from mcount is 0x2c, whereas from 1.2 onwards it is
992 * 0x30. bss_end has been rounded up to page boundary. This solution is
993 * based on suggestions made by Kevin Welton and Steve Hunt of Acorn, and
994 * avoids the need for a custom version of crt0.o for emacs which has its
995 * table in data space.
1001 char address_text
[32];
1006 int mcount_address
, mcount_offset
, count
;
1007 extern char *_execname
;
1010 /* The use of _execname is incompatible with RISCiX 1.1 */
1011 sprintf (command
, "nm %s | fgrep mcount", _execname
);
1013 if ( (pfile
= popen(command
, "r")) == NULL
)
1015 sprintf (errbuf
, "Could not open pipe");
1020 while ( ((c
=getc(pfile
)) != EOF
) && (c
!= ' ') && (count
< 31))
1021 address_text
[count
++]=c
;
1022 address_text
[count
]=0;
1024 if ((count
== 0) || pclose(pfile
) != NULL
)
1026 sprintf (errbuf
, "Failed to execute the command '%s'\n", command
);
1030 sscanf(address_text
, "%x", &mcount_address
);
1031 ptr
= (char *) unexec_text_start
;
1032 mcount_offset
= (char *)mcount_address
- ptr
;
1035 #define EDATA_OFFSET 0x2c
1037 #define EDATA_OFFSET 0x30
1040 end
= ptr
+ mcount_offset
- EDATA_OFFSET
;
1042 write_segment (new, ptr
, end
);
1044 proforma
[0] = bss_end
; /* becomes _edata */
1045 proforma
[1] = bss_end
; /* becomes _end */
1046 proforma
[2] = bss_end
; /* becomes _minbrk */
1047 proforma
[3] = bss_end
; /* becomes _curbrk */
1049 write (new, proforma
, 16);
1053 end
= temp_ptr
+ hdr
.a_text
;
1055 write_segment (new, ptr
, end
);
1059 ptr
= (char *) unexec_text_start
;
1060 end
= ptr
+ hdr
.a_text
;
1061 write_segment (new, ptr
, end
);
1064 ptr
= (char *) unexec_data_start
;
1065 end
= ptr
+ hdr
.a_data
;
1066 /* This lseek is certainly incorrect when A_TEXT_OFFSET
1067 and I believe it is a no-op otherwise.
1068 Let's see if its absence ever fails. */
1069 /* lseek (new, (long) N_TXTOFF (hdr) + hdr.a_text, 0); */
1070 write_segment (new, ptr
, end
);
1072 #endif /* not COFF */
1077 /* ****************************************************************
1080 * Copy the relocation information and symbol table from the a.out to the new
1083 copy_sym (new, a_out
, a_name
, new_name
)
1085 char *a_name
, *new_name
;
1094 if (SYMS_START
== 0L)
1099 if (lnnoptr
) /* if there is line number info */
1100 lseek (a_out
, coff_offset
+ lnnoptr
, 0); /* start copying from there */
1102 lseek (a_out
, coff_offset
+ SYMS_START
, 0); /* Position a.out to symtab. */
1103 #else /* not COFF */
1104 lseek (a_out
, SYMS_START
, 0); /* Position a.out to symtab. */
1105 #endif /* not COFF */
1107 while ((n
= read (a_out
, page
, sizeof page
)) > 0)
1109 if (write (new, page
, n
) != n
)
1121 /* ****************************************************************
1124 * After successfully building the new a.out, mark it executable
1132 int new = 0; /* for PERROR */
1136 if (stat (name
, &sbuf
) == -1)
1140 sbuf
.st_mode
|= 0111 & ~um
;
1141 if (chmod (name
, sbuf
.st_mode
) == -1)
1146 #ifndef COFF_BSD_SYMBOLS
1149 * If the COFF file contains a symbol table and a line number section,
1150 * then any auxiliary entries that have values for x_lnnoptr must
1151 * be adjusted by the amount that the line number section has moved
1152 * in the file (bias computed in make_hdr). The #@$%&* designers of
1153 * the auxiliary entry structures used the absolute file offsets for
1154 * the line number entry rather than an offset from the start of the
1155 * line number section!
1157 * When I figure out how to scan through the symbol table and pick out
1158 * the auxiliary entries that need adjustment, this routine will
1159 * be fixed. As it is now, all such entries are wrong and sdb
1160 * will complain. Fred Fish, UniSoft Systems Inc.
1163 /* This function is probably very slow. Instead of reopening the new
1164 file for input and output it should copy from the old to the new
1165 using the two descriptors already open (WRITEDESC and READDESC).
1166 Instead of reading one small structure at a time it should use
1167 a reasonable size buffer. But I don't have time to work on such
1168 things, so I am installing it as submitted to me. -- RMS. */
1170 adjust_lnnoptrs (writedesc
, readdesc
, new_name
)
1177 #if defined (amdahl_uts) || defined (pfa)
1181 struct syment symentry
;
1182 union auxent auxentry
;
1185 if (!lnnoptr
|| !f_hdr
.f_symptr
)
1189 if ((new = writedesc
) < 0)
1191 if ((new = open (new_name
, O_RDWR
)) < 0)
1198 lseek (new, f_hdr
.f_symptr
, 0);
1199 for (nsyms
= 0; nsyms
< f_hdr
.f_nsyms
; nsyms
++)
1201 read (new, &symentry
, SYMESZ
);
1202 if (symentry
.n_numaux
)
1204 read (new, &auxentry
, AUXESZ
);
1206 if (ISFCN (symentry
.n_type
) || symentry
.n_type
== 0x2400)
1208 auxentry
.x_sym
.x_fcnary
.x_fcn
.x_lnnoptr
+= bias
;
1209 lseek (new, -AUXESZ
, 1);
1210 write (new, &auxentry
, AUXESZ
);
1220 #endif /* COFF_BSD_SYMBOLS */
1224 /* ****************************************************************
1229 unexec (new_name
, a_name
, data_start
, bss_start
, entry_address
)
1230 char *new_name
, *a_name
;
1231 unsigned data_start
, bss_start
, entry_address
;
1233 int new, a_out
= -1;
1235 if (a_name
&& (a_out
= open (a_name
, O_RDONLY
)) < 0)
1239 if ((new = creat (new_name
, 0666)) < 0)
1244 if (make_hdr (new, a_out
, data_start
, bss_start
, entry_address
, a_name
, new_name
) < 0
1245 || copy_text_and_data (new, a_out
) < 0
1246 || copy_sym (new, a_out
, a_name
, new_name
) < 0
1248 #ifndef COFF_BSD_SYMBOLS
1249 || adjust_lnnoptrs (new, a_out
, new_name
) < 0
1255 /* unlink (new_name); /* Failed, unlink new a.out */
1266 #endif /* not CANNOT_DUMP */
1268 /* arch-tag: 62409b69-e27a-4a7c-9413-0210d6b54e7f
1269 (do not change this comment) */