]>
code.delx.au - gnu-emacs/blob - src/unexec.c
1 /* Copyright (C) 1985, 1986, 1987, 1988 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 1, 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, 675 Mass Ave, Cambridge, MA 02139, USA. */
21 * unexec.c - Convert a running program into an a.out file.
23 * Author: Spencer W. Thomas
24 * Computer Science Dept.
26 * Date: Tue Mar 2 1982
27 * Modified heavily since then.
30 * unexec (new_name, a_name, data_start, bss_start, entry_address)
31 * char *new_name, *a_name;
32 * unsigned data_start, bss_start, entry_address;
34 * Takes a snapshot of the program and makes an a.out format file in the
35 * file named by the string argument new_name.
36 * If a_name is non-NULL, the symbol table will be taken from the given file.
37 * On some machines, an existing a_name file is required.
39 * The boundaries within the a.out file may be adjusted with the data_start
40 * and bss_start arguments. Either or both may be given as 0 for defaults.
42 * Data_start gives the boundary between the text segment and the data
43 * segment of the program. The text segment can contain shared, read-only
44 * program code and literal data, while the data segment is always unshared
45 * and unprotected. Data_start gives the lowest unprotected address.
46 * The value you specify may be rounded down to a suitable boundary
47 * as required by the machine you are using.
49 * Specifying zero for data_start means the boundary between text and data
50 * should not be the same as when the program was loaded.
51 * If NO_REMAP is defined, the argument data_start is ignored and the
52 * segment boundaries are never changed.
54 * Bss_start indicates how much of the data segment is to be saved in the
55 * a.out file and restored when the program is executed. It gives the lowest
56 * unsaved address, and is rounded up to a page boundary. The default when 0
57 * is given assumes that the entire data segment is to be stored, including
58 * the previous data and bss as well as any additional storage allocated with
61 * The new file is set up to start at entry_address.
63 * If you make improvements I'd like to get them too.
64 * harpo!utah-cs!thomas, thomas@Utah-20
68 /* Modified to support SysVr3 shared libraries by James Van Artsdalen
69 * of Dell Computer Corporation. james@bigtex.cactus.org.
72 /* There are several compilation parameters affecting unexec:
76 Define this if your system uses COFF for executables.
77 Otherwise we assume you use Berkeley format.
81 Define this if you do not want to try to save Emacs's pure data areas
82 as part of the text segment.
84 Saving them as text is good because it allows users to share more.
86 However, on machines that locate the text area far from the data area,
87 the boundary cannot feasibly be moved. Such machines require
90 Also, remapping can cause trouble with the built-in startup routine
91 /lib/crt0.o, which defines `environ' as an initialized variable.
92 Dumping `environ' as pure does not work! So, to use remapping,
93 you must write a startup routine for your machine in Emacs's crt0.c.
94 If NO_REMAP is defined, Emacs uses the system's crt0.o.
98 Some machines that use COFF executables require that each section
99 start on a certain boundary *in the COFF file*. Such machines should
100 define SECTION_ALIGNMENT to a mask of the low-order bits that must be
101 zero on such a boundary. This mask is used to control padding between
102 segments in the COFF file.
104 If SECTION_ALIGNMENT is not defined, the segments are written
105 consecutively with no attempt at alignment. This is right for
110 Some machines require that the beginnings and ends of segments
111 *in core* be on certain boundaries. For most machines, a page
112 boundary is sufficient. That is the default. When a larger
113 boundary is needed, define SEGMENT_MASK to a mask of
114 the bits that must be zero on such a boundary.
118 Some machines count the a.out header as part of the size of the text
119 segment (a_text); they may actually load the header into core as the
120 first data in the text segment. Some have additional padding between
121 the header and the real text of the program that is counted in a_text.
123 For these machines, define A_TEXT_OFFSET(HDR) to examine the header
124 structure HDR and return the number of bytes to add to `a_text'
125 before writing it (above and beyond the number of bytes of actual
126 program text). HDR's standard fields are already correct, except that
127 this adjustment to the `a_text' field has not yet been made;
128 thus, the amount of offset can depend on the data in the file.
132 If defined, this macro specifies the number of bytes to seek into the
133 a.out file before starting to write the text segment.a
137 For machines using COFF, this macro, if defined, is a value stored
138 into the magic number field of the output file.
142 This macro can be used to generate statements to adjust or
143 initialize nonstandard fields in the file header
147 Macro to correct an int which is the bit pattern of a pointer to a byte
148 into an int which is the number of a byte.
150 This macro has a default definition which is usually right.
151 This default definition is a no-op on most machines (where a
152 pointer looks like an int) but not on all machines.
157 #define PERROR(arg) perror (arg); return -1
161 #define PERROR(file) report_error (file, new)
164 #ifndef CANNOT_DUMP /* all rest of file! */
166 #ifndef CANNOT_UNEXEC /* most of rest of file */
169 /* Define getpagesize () if the system does not.
170 Note that this may depend on symbols defined in a.out.h
172 #include "getpagesize.h"
174 #ifndef makedev /* Try to detect types.h already loaded */
175 #include <sys/types.h>
178 #include <sys/stat.h>
181 extern char *start_of_text (); /* Start of text */
182 extern char *start_of_data (); /* Start of initialized data */
185 static long block_copy_start
; /* Old executable start point */
186 static struct filehdr f_hdr
; /* File header */
187 static struct aouthdr f_ohdr
; /* Optional file header (a.out) */
188 long bias
; /* Bias to add for growth */
189 long lnnoptr
; /* Pointer to line-number info within file */
190 #define SYMS_START block_copy_start
192 static long text_scnptr
;
193 static long data_scnptr
;
197 extern char *sbrk ();
199 #define SYMS_START ((long) N_SYMOFF (ohdr))
201 /* Some machines override the structure name for an a.out header. */
202 #ifndef EXEC_HDR_TYPE
203 #define EXEC_HDR_TYPE struct exec
208 #define MY_ID HP9000S200_ID
212 #endif /* no HP9000S200_ID */
213 static MAGIC OLDMAGIC
= {MY_ID
, SHARE_MAGIC
};
214 static MAGIC NEWMAGIC
= {MY_ID
, DEMAND_MAGIC
};
215 #define N_TXTOFF(x) TEXT_OFFSET(x)
216 #define N_SYMOFF(x) LESYM_OFFSET(x)
217 static EXEC_HDR_TYPE hdr
, ohdr
;
221 #if defined (USG) && !defined (IBMAIX) && !defined (IRIS)
222 static struct bhdr hdr
, ohdr
;
223 #define a_magic fmagic
228 #define a_trsize rtsize
229 #define a_drsize rdsize
230 #define a_entry entry
231 #define N_BADMAG(x) \
232 (((x).fmagic)!=OMAGIC && ((x).fmagic)!=NMAGIC &&\
233 ((x).fmagic)!=FMAGIC && ((x).fmagic)!=IMAGIC)
234 #define NEWMAGIC FMAGIC
235 #else /* IRIS or IBMAIX or not USG */
236 static EXEC_HDR_TYPE hdr
, ohdr
;
237 #define NEWMAGIC ZMAGIC
238 #endif /* IRIS or IBMAIX not USG */
239 #endif /* not HPUX */
241 static int unexec_text_start
;
242 static int unexec_data_start
;
244 #endif /* not COFF */
248 /* Correct an int which is the bit pattern of a pointer to a byte
249 into an int which is the number of a byte.
250 This is a no-op on ordinary machines, but not on all. */
252 #ifndef ADDR_CORRECT /* Let m-*.h files override this definition */
253 #define ADDR_CORRECT(x) ((char *)(x) - (char*)0)
259 report_error (file
, fd
)
265 error ("Failure operating on %s\n", file
);
269 #define ERROR0(msg) report_error_1 (new, msg, 0, 0); return -1
270 #define ERROR1(msg,x) report_error_1 (new, msg, x, 0); return -1
271 #define ERROR2(msg,x,y) report_error_1 (new, msg, x, y); return -1
274 report_error_1 (fd
, msg
, a1
, a2
)
283 fprintf (stderr
, msg
, a1
, a2
);
284 fprintf (stderr
, "\n");
288 static int make_hdr ();
289 static int copy_text_and_data ();
290 static int copy_sym ();
291 static void mark_x ();
293 /* ****************************************************************
298 unexec (new_name
, a_name
, data_start
, bss_start
, entry_address
)
299 char *new_name
, *a_name
;
300 unsigned data_start
, bss_start
, entry_address
;
304 if (a_name
&& (a_out
= open (a_name
, 0)) < 0)
308 if ((new = creat (new_name
, 0666)) < 0)
313 if (make_hdr (new, a_out
, data_start
, bss_start
, entry_address
, a_name
, new_name
) < 0
314 || copy_text_and_data (new, a_out
) < 0
315 || copy_sym (new, a_out
, a_name
, new_name
) < 0
317 #ifndef COFF_BSD_SYMBOLS
318 || adjust_lnnoptrs (new, a_out
, new_name
) < 0
324 /* unlink (new_name); /* Failed, unlink new a.out */
335 /* ****************************************************************
338 * Make the header in the new a.out from the header in core.
339 * Modify the text and data sizes.
342 make_hdr (new, a_out
, data_start
, bss_start
, entry_address
, a_name
, new_name
)
344 unsigned data_start
, bss_start
, entry_address
;
350 auto struct scnhdr f_thdr
; /* Text section header */
351 auto struct scnhdr f_dhdr
; /* Data section header */
352 auto struct scnhdr f_bhdr
; /* Bss section header */
353 auto struct scnhdr scntemp
; /* Temporary section header */
356 #ifdef USG_SHARED_LIBRARIES
357 extern unsigned int bss_end
;
359 unsigned int bss_end
;
362 pagemask
= getpagesize () - 1;
364 /* Adjust text/data boundary. */
366 data_start
= (int) start_of_data ();
367 #else /* not NO_REMAP */
369 data_start
= (int) start_of_data ();
370 #endif /* not NO_REMAP */
371 data_start
= ADDR_CORRECT (data_start
);
374 data_start
= data_start
& ~SEGMENT_MASK
; /* (Down) to segment boundary. */
376 data_start
= data_start
& ~pagemask
; /* (Down) to page boundary. */
379 bss_end
= ADDR_CORRECT (sbrk (0)) + pagemask
;
380 bss_end
&= ~ pagemask
;
382 /* Adjust data/bss boundary. */
385 bss_start
= (ADDR_CORRECT (bss_start
) + pagemask
);
386 /* (Up) to page bdry. */
387 bss_start
&= ~ pagemask
;
388 if (bss_start
> bss_end
)
390 ERROR1 ("unexec: Specified bss_start (%u) is past end of program",
397 if (data_start
> bss_start
) /* Can't have negative data size. */
399 ERROR2 ("unexec: data_start (%u) can't be greater than bss_start (%u)",
400 data_start
, bss_start
);
404 /* Salvage as much info from the existing file as possible */
407 if (read (a_out
, &f_hdr
, sizeof (f_hdr
)) != sizeof (f_hdr
))
411 block_copy_start
+= sizeof (f_hdr
);
412 if (f_hdr
.f_opthdr
> 0)
414 if (read (a_out
, &f_ohdr
, sizeof (f_ohdr
)) != sizeof (f_ohdr
))
418 block_copy_start
+= sizeof (f_ohdr
);
420 /* Loop through section headers, copying them in */
421 for (scns
= f_hdr
.f_nscns
; scns
> 0; scns
--) {
422 if (read (a_out
, &scntemp
, sizeof (scntemp
)) != sizeof (scntemp
))
426 if (scntemp
.s_scnptr
> 0L)
428 if (block_copy_start
< scntemp
.s_scnptr
+ scntemp
.s_size
)
429 block_copy_start
= scntemp
.s_scnptr
+ scntemp
.s_size
;
431 if (strcmp (scntemp
.s_name
, ".text") == 0)
435 else if (strcmp (scntemp
.s_name
, ".data") == 0)
439 else if (strcmp (scntemp
.s_name
, ".bss") == 0)
447 ERROR0 ("can't build a COFF file from scratch yet");
450 /* Now we alter the contents of all the f_*hdr variables
451 to correspond to what we want to dump. */
453 #ifdef USG_SHARED_LIBRARIES
455 /* The amount of data we're adding to the file is distance from the
456 * end of the original .data space to the current end of the .data
460 bias
= bss_end
- (f_ohdr
.data_start
+ f_dhdr
.s_size
);
464 f_hdr
.f_flags
|= (F_RELFLG
| F_EXEC
);
469 f_ohdr
.magic
= EXEC_MAGIC
;
472 f_ohdr
.text_start
= (long) start_of_text ();
473 f_ohdr
.tsize
= data_start
- f_ohdr
.text_start
;
474 f_ohdr
.data_start
= data_start
;
475 #endif /* NO_REMAP */
476 f_ohdr
.dsize
= bss_start
- f_ohdr
.data_start
;
477 f_ohdr
.bsize
= bss_end
- bss_start
;
478 #ifndef KEEP_OLD_TEXT_SCNPTR
479 /* On some machines, the old values are right.
480 ??? Maybe on all machines with NO_REMAP. */
481 f_thdr
.s_size
= f_ohdr
.tsize
;
482 f_thdr
.s_scnptr
= sizeof (f_hdr
) + sizeof (f_ohdr
);
483 f_thdr
.s_scnptr
+= (f_hdr
.f_nscns
) * (sizeof (f_thdr
));
484 #endif /* KEEP_OLD_TEXT_SCNPTR */
485 #ifdef ADJUST_TEXT_SCNHDR_SIZE
486 /* On some machines, `text size' includes all headers. */
487 f_thdr
.s_size
-= f_thdr
.s_scnptr
;
488 #endif /* ADJUST_TEST_SCNHDR_SIZE */
489 lnnoptr
= f_thdr
.s_lnnoptr
;
490 #ifdef SECTION_ALIGNMENT
491 /* Some systems require special alignment
492 of the sections in the file itself. */
494 = (f_thdr
.s_scnptr
+ SECTION_ALIGNMENT
) & ~SECTION_ALIGNMENT
;
495 #endif /* SECTION_ALIGNMENT */
497 f_thdr
.s_scnptr
= 0xd0;
499 text_scnptr
= f_thdr
.s_scnptr
;
500 #ifdef ADJUST_TEXTBASE
501 text_scnptr
= sizeof (f_hdr
) + sizeof (f_ohdr
) + (f_hdr
.f_nscns
) * (sizeof (f_thdr
));
503 #ifndef KEEP_OLD_PADDR
504 f_dhdr
.s_paddr
= f_ohdr
.data_start
;
505 #endif /* KEEP_OLD_PADDR */
506 f_dhdr
.s_vaddr
= f_ohdr
.data_start
;
507 f_dhdr
.s_size
= f_ohdr
.dsize
;
508 f_dhdr
.s_scnptr
= f_thdr
.s_scnptr
+ f_thdr
.s_size
;
509 #ifdef SECTION_ALIGNMENT
510 /* Some systems require special alignment
511 of the sections in the file itself. */
513 = (f_dhdr
.s_scnptr
+ SECTION_ALIGNMENT
) & ~SECTION_ALIGNMENT
;
514 #endif /* SECTION_ALIGNMENT */
515 #ifdef DATA_SECTION_ALIGNMENT
516 /* Some systems require special alignment
517 of the data section only. */
519 = (f_dhdr
.s_scnptr
+ DATA_SECTION_ALIGNMENT
) & ~DATA_SECTION_ALIGNMENT
;
520 #endif /* DATA_SECTION_ALIGNMENT */
521 data_scnptr
= f_dhdr
.s_scnptr
;
522 #ifndef KEEP_OLD_PADDR
523 f_bhdr
.s_paddr
= f_ohdr
.data_start
+ f_ohdr
.dsize
;
524 #endif /* KEEP_OLD_PADDR */
525 f_bhdr
.s_vaddr
= f_ohdr
.data_start
+ f_ohdr
.dsize
;
526 f_bhdr
.s_size
= f_ohdr
.bsize
;
527 f_bhdr
.s_scnptr
= 0L;
528 #ifndef USG_SHARED_LIBRARIES
529 bias
= f_dhdr
.s_scnptr
+ f_dhdr
.s_size
- block_copy_start
;
532 if (f_hdr
.f_symptr
> 0L)
534 f_hdr
.f_symptr
+= bias
;
537 if (f_thdr
.s_lnnoptr
> 0L)
539 f_thdr
.s_lnnoptr
+= bias
;
542 #ifdef ADJUST_EXEC_HEADER
544 #endif /* ADJUST_EXEC_HEADER */
546 if (write (new, &f_hdr
, sizeof (f_hdr
)) != sizeof (f_hdr
))
551 if (write (new, &f_ohdr
, sizeof (f_ohdr
)) != sizeof (f_ohdr
))
556 #ifndef USG_SHARED_LIBRARIES
558 if (write (new, &f_thdr
, sizeof (f_thdr
)) != sizeof (f_thdr
))
563 if (write (new, &f_dhdr
, sizeof (f_dhdr
)) != sizeof (f_dhdr
))
568 if (write (new, &f_bhdr
, sizeof (f_bhdr
)) != sizeof (f_bhdr
))
573 #else /* USG_SHARED_LIBRARIES */
575 /* The purpose of this code is to write out the new file's section
578 * Scan through the original file's sections. If the encountered
579 * section is one we know (.text, .data or .bss), write out the
580 * correct header. If it is a section we do not know (such as
581 * .lib), adjust the address of where the section data is in the
582 * file, and write out the header.
584 * If any section preceeds .text or .data in the file, this code
585 * will not adjust the file pointer for that section correctly.
588 lseek (a_out
, sizeof (f_hdr
) + sizeof (f_ohdr
), 0);
590 for (scns
= f_hdr
.f_nscns
; scns
> 0; scns
--)
592 if (read (a_out
, &scntemp
, sizeof (scntemp
)) != sizeof (scntemp
))
595 if (!strcmp (scntemp
.s_name
, f_thdr
.s_name
)) /* .text */
597 if (write (new, &f_thdr
, sizeof (f_thdr
)) != sizeof (f_thdr
))
600 else if (!strcmp (scntemp
.s_name
, f_dhdr
.s_name
)) /* .data */
602 if (write (new, &f_dhdr
, sizeof (f_dhdr
)) != sizeof (f_dhdr
))
605 else if (!strcmp (scntemp
.s_name
, f_bhdr
.s_name
)) /* .bss */
607 if (write (new, &f_bhdr
, sizeof (f_bhdr
)) != sizeof (f_bhdr
))
612 if (scntemp
.s_scnptr
)
613 scntemp
.s_scnptr
+= bias
;
614 if (write (new, &scntemp
, sizeof (scntemp
)) != sizeof (scntemp
))
618 #endif /* USG_SHARED_LIBRARIES */
622 #else /* if not COFF */
624 /* Get symbol table info from header of a.out file if given one. */
627 if (read (a_out
, &ohdr
, sizeof hdr
) != sizeof hdr
)
634 ERROR1 ("invalid magic number in %s", a_name
);
640 bzero (hdr
, sizeof hdr
);
643 unexec_text_start
= (long) start_of_text ();
644 unexec_data_start
= data_start
;
646 /* Machine-dependent fixup for header, or maybe for unexec_text_start */
647 #ifdef ADJUST_EXEC_HEADER
649 #endif /* ADJUST_EXEC_HEADER */
653 if (entry_address
!= 0)
654 hdr
.a_entry
= entry_address
;
656 hdr
.a_bss
= bss_end
- bss_start
;
657 hdr
.a_data
= bss_start
- data_start
;
659 hdr
.a_text
= ohdr
.a_text
;
660 #else /* not NO_REMAP */
661 hdr
.a_text
= data_start
- unexec_text_start
;
664 hdr
.a_text
+= A_TEXT_OFFSET (ohdr
);
667 #endif /* not NO_REMAP */
669 if (write (new, &hdr
, sizeof hdr
) != sizeof hdr
)
675 hdr
.a_text
-= A_TEXT_OFFSET (ohdr
);
680 #endif /* not COFF */
683 /* ****************************************************************
686 * Copy the text and data segments from memory to the new a.out
689 copy_text_and_data (new, a_out
)
697 #ifdef USG_SHARED_LIBRARIES
700 struct scnhdr scntemp
; /* Temporary section header */
702 /* The purpose of this code is to write out the new file's section
705 * Step through the section table. If we know the section (.text,
706 * .data) do the appropriate thing. Otherwise, if the section has
707 * no allocated space in the file (.bss), do nothing. Otherwise,
708 * the section has space allocated in the file, and is not a section
709 * we know. So just copy it.
712 lseek (a_out
, sizeof (struct filehdr
) + sizeof (struct aouthdr
), 0);
714 for (scns
= f_hdr
.f_nscns
; scns
> 0; scns
--)
716 if (read (a_out
, &scntemp
, sizeof (scntemp
)) != sizeof (scntemp
))
719 if (!strcmp (scntemp
.s_name
, ".text"))
721 lseek (new, (long) text_scnptr
, 0);
722 ptr
= (char *) f_ohdr
.text_start
;
723 end
= ptr
+ f_ohdr
.tsize
;
724 write_segment (new, ptr
, end
);
726 else if (!strcmp (scntemp
.s_name
, ".data"))
728 lseek (new, (long) data_scnptr
, 0);
729 ptr
= (char *) f_ohdr
.data_start
;
730 end
= ptr
+ f_ohdr
.dsize
;
731 write_segment (new, ptr
, end
);
733 else if (!scntemp
.s_scnptr
)
734 ; /* do nothing - no data for this section */
739 long old_a_out_ptr
= lseek (a_out
, 0, 1);
741 lseek (a_out
, scntemp
.s_scnptr
, 0);
742 for (size
= scntemp
.s_size
; size
> 0; size
-= sizeof (page
))
744 n
= size
> sizeof (page
) ? sizeof (page
) : size
;
745 if (read (a_out
, page
, n
) != n
|| write (new, page
, n
) != n
)
748 lseek (a_out
, old_a_out_ptr
, 0);
752 #else /* COFF, but not USG_SHARED_LIBRARIES */
754 lseek (new, (long) text_scnptr
, 0);
755 ptr
= (char *) f_ohdr
.text_start
;
756 #ifdef HEADER_INCL_IN_TEXT
757 /* For Gould UTX/32, text starts after headers */
758 ptr
= (char *) (ptr
+ text_scnptr
);
759 #endif /* HEADER_INCL_IN_TEXT */
760 end
= ptr
+ f_ohdr
.tsize
;
761 write_segment (new, ptr
, end
);
763 lseek (new, (long) data_scnptr
, 0);
764 ptr
= (char *) f_ohdr
.data_start
;
765 end
= ptr
+ f_ohdr
.dsize
;
766 write_segment (new, ptr
, end
);
768 #endif /* USG_SHARED_LIBRARIES */
770 #else /* if not COFF */
772 /* Some machines count the header as part of the text segment.
773 That is to say, the header appears in core
774 just before the address that start_of_text () returns.
775 For them, N_TXTOFF is the place where the header goes.
776 We must adjust the seek to the place after the header.
777 Note that at this point hdr.a_text does *not* count
778 the extra A_TEXT_OFFSET bytes, only the actual bytes of code. */
781 lseek (new, (long) A_TEXT_SEEK (hdr
), 0);
783 lseek (new, (long) N_TXTOFF (hdr
), 0);
784 #endif /* no A_TEXT_SEEK */
786 ptr
= (char *) unexec_text_start
;
787 end
= ptr
+ hdr
.a_text
;
788 write_segment (new, ptr
, end
);
790 ptr
= (char *) unexec_data_start
;
791 end
= ptr
+ hdr
.a_data
;
792 /* This lseek is certainly incorrect when A_TEXT_OFFSET
793 and I believe it is a no-op otherwise.
794 Let's see if its absence ever fails. */
795 /* lseek (new, (long) N_TXTOFF (hdr) + hdr.a_text, 0); */
796 write_segment (new, ptr
, end
);
798 #endif /* not COFF */
803 write_segment (new, ptr
, end
)
805 register char *ptr
, *end
;
807 register int i
, nwrite
, ret
;
812 bzero (zeros
, sizeof zeros
);
814 for (i
= 0; ptr
< end
;)
816 /* distance to next multiple of 128. */
817 nwrite
= (((int) ptr
+ 128) & -128) - (int) ptr
;
818 /* But not beyond specified end. */
819 if (nwrite
> end
- ptr
) nwrite
= end
- ptr
;
820 ret
= write (new, ptr
, nwrite
);
821 /* If write gets a page fault, it means we reached
822 a gap between the old text segment and the old data segment.
823 This gap has probably been remapped into part of the text segment.
824 So write zeros for it. */
825 if (ret
== -1 && errno
== EFAULT
)
826 write (new, zeros
, nwrite
);
827 else if (nwrite
!= ret
)
830 "unexec write failure: addr 0x%x, fileno %d, size 0x%x, wrote 0x%x, errno %d",
831 ptr
, new, nwrite
, ret
, errno
);
839 /* ****************************************************************
842 * Copy the relocation information and symbol table from the a.out to the new
845 copy_sym (new, a_out
, a_name
, new_name
)
847 char *a_name
, *new_name
;
856 if (SYMS_START
== 0L)
861 if (lnnoptr
) /* if there is line number info */
862 lseek (a_out
, lnnoptr
, 0); /* start copying from there */
865 lseek (a_out
, SYMS_START
, 0); /* Position a.out to symtab. */
867 while ((n
= read (a_out
, page
, sizeof page
)) > 0)
869 if (write (new, page
, n
) != n
)
881 /* ****************************************************************
884 * After succesfully building the new a.out, mark it executable
892 int new = 0; /* for PERROR */
896 if (stat (name
, &sbuf
) == -1)
900 sbuf
.st_mode
|= 0111 & ~um
;
901 if (chmod (name
, sbuf
.st_mode
) == -1)
906 #ifndef COFF_BSD_SYMBOLS
909 * If the COFF file contains a symbol table and a line number section,
910 * then any auxiliary entries that have values for x_lnnoptr must
911 * be adjusted by the amount that the line number section has moved
912 * in the file (bias computed in make_hdr). The #@$%&* designers of
913 * the auxiliary entry structures used the absolute file offsets for
914 * the line number entry rather than an offset from the start of the
915 * line number section!
917 * When I figure out how to scan through the symbol table and pick out
918 * the auxiliary entries that need adjustment, this routine will
919 * be fixed. As it is now, all such entries are wrong and sdb
920 * will complain. Fred Fish, UniSoft Systems Inc.
923 /* This function is probably very slow. Instead of reopening the new
924 file for input and output it should copy from the old to the new
925 using the two descriptors already open (WRITEDESC and READDESC).
926 Instead of reading one small structure at a time it should use
927 a reasonable size buffer. But I don't have time to work on such
928 things, so I am installing it as submitted to me. -- RMS. */
930 adjust_lnnoptrs (writedesc
, readdesc
, new_name
)
941 struct syment symentry
;
942 union auxent auxentry
;
945 if (!lnnoptr
|| !f_hdr
.f_symptr
)
948 if ((new = open (new_name
, 2)) < 0)
954 lseek (new, f_hdr
.f_symptr
, 0);
955 for (nsyms
= 0; nsyms
< f_hdr
.f_nsyms
; nsyms
++)
957 read (new, &symentry
, SYMESZ
);
958 if (symentry
.n_numaux
)
960 read (new, &auxentry
, AUXESZ
);
962 if (ISFCN (symentry
.n_type
)) {
963 auxentry
.x_sym
.x_fcnary
.x_fcn
.x_lnnoptr
+= bias
;
964 lseek (new, -AUXESZ
, 1);
965 write (new, &auxentry
, AUXESZ
);
972 #endif /* COFF_BSD_SYMBOLS */
976 #endif /* not CANNOT_UNEXEC */
978 #endif /* not CANNOT_DUMP */