1 /* Copyright (C) 1985, 1986, 1987, 1988, 1992, 1993, 1994
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 19.31. */
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 /* Modified to support SysVr3 shared libraries by James Van Artsdalen
72 * of Dell Computer Corporation. james@bigtex.cactus.org.
75 /* There are several compilation parameters affecting unexec:
79 Define this if your system uses COFF for executables.
83 Define this if you are using the GNU coff encapsulated a.out format.
84 This is closer to a.out than COFF. You should *not* define COFF if
85 you define COFF_ENCAPSULATE
87 Otherwise we assume you use Berkeley format.
91 Define this if you do not want to try to save Emacs's pure data areas
92 as part of the text segment.
94 Saving them as text is good because it allows users to share more.
96 However, on machines that locate the text area far from the data area,
97 the boundary cannot feasibly be moved. Such machines require
100 Also, remapping can cause trouble with the built-in startup routine
101 /lib/crt0.o, which defines `environ' as an initialized variable.
102 Dumping `environ' as pure does not work! So, to use remapping,
103 you must write a startup routine for your machine in Emacs's crt0.c.
104 If NO_REMAP is defined, Emacs uses the system's crt0.o.
108 Some machines that use COFF executables require that each section
109 start on a certain boundary *in the COFF file*. Such machines should
110 define SECTION_ALIGNMENT to a mask of the low-order bits that must be
111 zero on such a boundary. This mask is used to control padding between
112 segments in the COFF file.
114 If SECTION_ALIGNMENT is not defined, the segments are written
115 consecutively with no attempt at alignment. This is right for
120 Some machines require that the beginnings and ends of segments
121 *in core* be on certain boundaries. For most machines, a page
122 boundary is sufficient. That is the default. When a larger
123 boundary is needed, define SEGMENT_MASK to a mask of
124 the bits that must be zero on such a boundary.
128 Some machines count the a.out header as part of the size of the text
129 segment (a_text); they may actually load the header into core as the
130 first data in the text segment. Some have additional padding between
131 the header and the real text of the program that is counted in a_text.
133 For these machines, define A_TEXT_OFFSET(HDR) to examine the header
134 structure HDR and return the number of bytes to add to `a_text'
135 before writing it (above and beyond the number of bytes of actual
136 program text). HDR's standard fields are already correct, except that
137 this adjustment to the `a_text' field has not yet been made;
138 thus, the amount of offset can depend on the data in the file.
142 If defined, this macro specifies the number of bytes to seek into the
143 a.out file before starting to write the text segment.
147 For machines using COFF, this macro, if defined, is a value stored
148 into the magic number field of the output file.
152 This macro can be used to generate statements to adjust or
153 initialize nonstandard fields in the file header
157 Macro to correct an int which is the bit pattern of a pointer to a byte
158 into an int which is the number of a byte.
160 This macro has a default definition which is usually right.
161 This default definition is a no-op on most machines (where a
162 pointer looks like an int) but not on all machines.
167 #define PERROR(arg) perror (arg); return -1
170 #define DONT_ENCAPSULATE /* we include lisp.h so we want to make sure we
171 don't get filename conversion. The caller
172 of unexec() is assumed to have done this
173 already (it's easier to do it this way than
174 to modify all the unexec modules to ensure
175 that all weirdo functions, such as
176 elf_write_modified_data(), have proper
177 filename conversion applied). */
179 #define PERROR(file) report_error (file, new)
182 #if __STDC__ || defined(STDC_HEADERS)
184 /* I don't know how correct this attempt to get more prototypes is... */
185 # if defined(sun) && defined(_POSIX_SOURCE)
186 # undef _POSIX_SOURCE
189 # if defined(__lucid) && !defined(__STDC_EXTENDED__)
190 # define __STDC_EXTENDED__ 1
205 /* I don't understand this, but it's necessary to get some slots in struct exec
206 from /usr/include/sys/exec.h when running LCC in strict ANSI mode. We don't
207 need this in K&R mode...
209 #if defined(__lucid) && defined(__sparc) && !defined(sun)
213 #ifndef CANNOT_DUMP /* all rest of file! */
215 #ifdef COFF_ENCAPSULATE
216 int need_coff_header = 1;
217 #include <coff-encap/a.out.encap.h> /* The location might be a poor assumption */
221 #include <fcntl.h> /* for O_RDONLY, O_RDWR */
224 #define filehdr external_filehdr
225 #define scnhdr external_scnhdr
226 #define syment external_syment
227 #define auxent external_auxent
228 #define n_numaux e_numaux
229 #define n_type e_type
232 unsigned short magic; /* type of file */
233 unsigned short vstamp; /* version stamp */
234 unsigned long tsize; /* text size in bytes, padded to FW bdry*/
235 unsigned long dsize; /* initialized data " " */
236 unsigned long bsize; /* uninitialized data " " */
237 unsigned long entry; /* entry pt. */
238 unsigned long text_start;/* base of text used for this file */
239 unsigned long data_start;/* base of data used for this file */
243 #else /* not MSDOS */
245 #endif /* not MSDOS */
246 #endif /* not COFF_ENCAPSULATE */
248 /* Define getpagesize if the system does not.
249 Note that this may depend on symbols defined in a.out.h. */
250 #include "getpagesize.h"
252 #ifndef makedev /* Try to detect types.h already loaded */
253 #include <sys/types.h>
256 #include <sys/stat.h>
259 #include <sys/file.h> /* Must be after sys/types.h for USG and BSD4_1*/
273 extern char *start_of_text (); /* Start of text */
275 extern void *start_of_data (); /* Start of initialized data */
278 static long block_copy_start; /* Old executable start point */
279 static struct filehdr f_hdr; /* File header */
280 static struct aouthdr f_ohdr; /* Optional file header (a.out) */
281 long bias; /* Bias to add for growth */
282 long lnnoptr; /* Pointer to line-number info within file */
283 #define SYMS_START block_copy_start
285 static long text_scnptr;
286 static long data_scnptr;
291 #ifndef __sys_stdtypes_h
292 #if !defined(_PTRDIFF_T) && !defined(_BSD_PTRDIFF_T_)
293 typedef long ptrdiff_t;
297 /* not sure where this for NetBSD should really go
298 and it probably applies to other systems */
299 #if !defined(__NetBSD__) && !defined(__bsdi__) && !defined(__OpenBSD__)
300 extern void *sbrk (ptrdiff_t);
302 extern char *sbrk ();
303 #endif /* __NetBSD__ or __OpenBSD__ */
306 extern void *sbrk ();
309 #define SYMS_START ((long) N_SYMOFF (ohdr))
311 /* Some machines override the structure name for an a.out header. */
312 #ifndef EXEC_HDR_TYPE
313 #define EXEC_HDR_TYPE struct exec
318 #define MY_ID HP9000S200_ID
322 #endif /* no HP9000S200_ID */
323 static MAGIC OLDMAGIC = {MY_ID, SHARE_MAGIC};
324 static MAGIC NEWMAGIC = {MY_ID, DEMAND_MAGIC};
325 #define N_TXTOFF(x) TEXT_OFFSET(x)
326 #define N_SYMOFF(x) LESYM_OFFSET(x)
327 static EXEC_HDR_TYPE hdr, ohdr;
331 #if defined (USG) && !defined (IBMAIX) && !defined (IRIS) && !defined (COFF_ENCAPSULATE) && !defined (LINUX)
332 static struct bhdr hdr, ohdr;
333 #define a_magic fmagic
338 #define a_trsize rtsize
339 #define a_drsize rdsize
340 #define a_entry entry
341 #define N_BADMAG(x) \
342 (((x).fmagic)!=OMAGIC && ((x).fmagic)!=NMAGIC &&\
343 ((x).fmagic)!=FMAGIC && ((x).fmagic)!=IMAGIC)
344 #define NEWMAGIC FMAGIC
345 #else /* IRIS or IBMAIX or not USG */
346 static EXEC_HDR_TYPE hdr, ohdr;
347 #define NEWMAGIC ZMAGIC
348 #endif /* IRIS or IBMAIX not USG */
349 #endif /* not HPUX */
351 static int unexec_text_start;
352 static int unexec_data_start;
354 #ifdef COFF_ENCAPSULATE
355 /* coffheader is defined in the GNU a.out.encap.h file. */
356 struct coffheader coffheader;
359 #endif /* not COFF */
363 /* Correct an int which is the bit pattern of a pointer to a byte
364 into an int which is the number of a byte.
365 This is a no-op on ordinary machines, but not on all. */
367 #ifndef ADDR_CORRECT /* Let m-*.h files override this definition */
368 #define ADDR_CORRECT(x) ((char *)(x) - (char*)0)
376 report_error (file, fd)
382 report_file_error ("Cannot unexec",
383 Fcons (build_ext_string (file, FORMAT_FILENAME), Qnil));
387 #define ERROR0(msg) report_error_1 (new, msg, 0, 0); return -1
388 #define ERROR1(msg,x) report_error_1 (new, msg, x, 0); return -1
389 #define ERROR2(msg,x,y) report_error_1 (new, msg, x, y); return -1
392 report_error_1 (fd, msg, a1, a2)
401 fprintf (stderr, msg, a1, a2);
402 fprintf (stderr, "\n");
406 static int make_hdr (int new, int a_out, unsigned data_start,
407 unsigned bss_start, unsigned entry_address,
408 char *a_name, char *new_name);
409 static int copy_text_and_data (int new, int a_out);
410 static int copy_sym (int new, int a_out, char *a_name, char *new_name);
411 static void mark_x (char *name);
413 /* ****************************************************************
419 unexec (new_name, a_name, data_start, bss_start, entry_address)
420 char *new_name, *a_name;
421 unsigned data_start, bss_start, entry_address;
425 if (a_name && (a_out = open (a_name, O_RDONLY)) < 0)
429 if ((new = creat (new_name, 0666)) < 0)
434 if (make_hdr (new, a_out, data_start, bss_start, entry_address, a_name, new_name) < 0
435 || copy_text_and_data (new, a_out) < 0
436 || copy_sym (new, a_out, a_name, new_name) < 0
438 #ifndef COFF_BSD_SYMBOLS
439 || adjust_lnnoptrs (new, a_out, new_name) < 0
445 /* unlink (new_name); / * Failed, unlink new a.out */
456 /* ****************************************************************
459 * Make the header in the new a.out from the header in core.
460 * Modify the text and data sizes.
463 make_hdr (int new, int a_out, unsigned data_start, unsigned bss_start,
464 unsigned entry_address, char *a_name, char *new_name)
467 auto struct scnhdr f_thdr; /* Text section header */
468 auto struct scnhdr f_dhdr; /* Data section header */
469 auto struct scnhdr f_bhdr; /* Bss section header */
470 auto struct scnhdr scntemp; /* Temporary section header */
473 #ifdef USG_SHARED_LIBRARIES
474 extern unsigned int bss_end;
476 unsigned int bss_end;
479 pagemask = getpagesize () - 1;
481 /* Adjust text/data boundary. */
483 data_start = (int) start_of_data ();
484 #else /* not NO_REMAP */
486 data_start = (int) start_of_data ();
487 #endif /* not NO_REMAP */
488 data_start = ADDR_CORRECT (data_start);
491 data_start = data_start & ~SEGMENT_MASK; /* (Down) to segment boundary. */
493 data_start = data_start & ~pagemask; /* (Down) to page boundary. */
496 bss_end = ADDR_CORRECT (sbrk (0)) + pagemask;
497 bss_end &= ~ pagemask;
499 /* Adjust data/bss boundary. */
502 bss_start = (ADDR_CORRECT (bss_start) + pagemask);
503 /* (Up) to page bdry. */
504 bss_start &= ~ pagemask;
505 if (bss_start > bss_end)
507 ERROR1 ("unexec: Specified bss_start (%u) is past end of program",
514 if (data_start > bss_start) /* Can't have negative data size. */
516 ERROR2 ("unexec: data_start (%u) can't be greater than bss_start (%u)",
517 data_start, bss_start);
521 /* Salvage as much info from the existing file as possible */
524 if (read (a_out, &f_hdr, sizeof (f_hdr)) != sizeof (f_hdr))
528 block_copy_start += sizeof (f_hdr);
529 if (f_hdr.f_opthdr > 0)
531 if (read (a_out, &f_ohdr, sizeof (f_ohdr)) != sizeof (f_ohdr))
535 block_copy_start += sizeof (f_ohdr);
537 /* Loop through section headers, copying them in */
538 lseek (a_out, sizeof (f_hdr) + f_hdr.f_opthdr, 0);
539 for (scns = f_hdr.f_nscns; scns > 0; scns--) {
540 if (read (a_out, &scntemp, sizeof (scntemp)) != sizeof (scntemp))
544 if (scntemp.s_scnptr > 0L)
546 if (block_copy_start < scntemp.s_scnptr + scntemp.s_size)
547 block_copy_start = scntemp.s_scnptr + scntemp.s_size;
549 if (strcmp (scntemp.s_name, ".text") == 0)
553 else if (strcmp (scntemp.s_name, ".data") == 0)
557 else if (strcmp (scntemp.s_name, ".bss") == 0)
565 ERROR0 ("can't build a COFF file from scratch yet");
568 /* Now we alter the contents of all the f_*hdr variables
569 to correspond to what we want to dump. */
571 #ifdef USG_SHARED_LIBRARIES
573 /* The amount of data we're adding to the file is distance from the
574 * end of the original .data space to the current end of the .data
578 bias = bss_start - (f_ohdr.data_start + f_dhdr.s_size);
582 f_hdr.f_flags |= (F_RELFLG | F_EXEC);
587 f_ohdr.magic = EXEC_MAGIC;
590 f_ohdr.text_start = (long) start_of_text ();
591 f_ohdr.tsize = data_start - f_ohdr.text_start;
592 f_ohdr.data_start = data_start;
593 #endif /* NO_REMAP */
594 f_ohdr.dsize = bss_start - f_ohdr.data_start;
595 f_ohdr.bsize = bss_end - bss_start;
596 #ifndef KEEP_OLD_TEXT_SCNPTR
597 /* On some machines, the old values are right.
598 ??? Maybe on all machines with NO_REMAP. */
599 f_thdr.s_size = f_ohdr.tsize;
600 f_thdr.s_scnptr = sizeof (f_hdr) + sizeof (f_ohdr);
601 f_thdr.s_scnptr += (f_hdr.f_nscns) * (sizeof (f_thdr));
602 #endif /* KEEP_OLD_TEXT_SCNPTR */
603 #ifdef ADJUST_TEXT_SCNHDR_SIZE
604 /* On some machines, `text size' includes all headers. */
605 f_thdr.s_size -= f_thdr.s_scnptr;
606 #endif /* ADJUST_TEST_SCNHDR_SIZE */
607 lnnoptr = f_thdr.s_lnnoptr;
608 #ifdef SECTION_ALIGNMENT
609 /* Some systems require special alignment
610 of the sections in the file itself. */
612 = (f_thdr.s_scnptr + SECTION_ALIGNMENT) & ~SECTION_ALIGNMENT;
613 #endif /* SECTION_ALIGNMENT */
615 f_thdr.s_scnptr = 0xd0;
617 text_scnptr = f_thdr.s_scnptr;
618 #ifdef ADJUST_TEXTBASE
619 text_scnptr = sizeof (f_hdr) + sizeof (f_ohdr) + (f_hdr.f_nscns) * (sizeof (f_thdr));
621 #ifndef KEEP_OLD_PADDR
622 f_dhdr.s_paddr = f_ohdr.data_start;
623 #endif /* KEEP_OLD_PADDR */
624 f_dhdr.s_vaddr = f_ohdr.data_start;
625 f_dhdr.s_size = f_ohdr.dsize;
626 f_dhdr.s_scnptr = f_thdr.s_scnptr + f_thdr.s_size;
627 #ifdef SECTION_ALIGNMENT
628 /* Some systems require special alignment
629 of the sections in the file itself. */
631 = (f_dhdr.s_scnptr + SECTION_ALIGNMENT) & ~SECTION_ALIGNMENT;
632 #endif /* SECTION_ALIGNMENT */
633 #ifdef DATA_SECTION_ALIGNMENT
634 /* Some systems require special alignment
635 of the data section only. */
637 = (f_dhdr.s_scnptr + DATA_SECTION_ALIGNMENT) & ~DATA_SECTION_ALIGNMENT;
638 #endif /* DATA_SECTION_ALIGNMENT */
639 data_scnptr = f_dhdr.s_scnptr;
640 #ifndef KEEP_OLD_PADDR
641 f_bhdr.s_paddr = f_ohdr.data_start + f_ohdr.dsize;
642 #endif /* KEEP_OLD_PADDR */
643 f_bhdr.s_vaddr = f_ohdr.data_start + f_ohdr.dsize;
644 f_bhdr.s_size = f_ohdr.bsize;
645 f_bhdr.s_scnptr = 0L;
646 #ifndef USG_SHARED_LIBRARIES
647 bias = f_dhdr.s_scnptr + f_dhdr.s_size - block_copy_start;
650 if (f_hdr.f_symptr > 0L)
652 f_hdr.f_symptr += bias;
655 if (f_thdr.s_lnnoptr > 0L)
657 f_thdr.s_lnnoptr += bias;
660 #ifdef ADJUST_EXEC_HEADER
662 #endif /* ADJUST_EXEC_HEADER */
664 if (write (new, &f_hdr, sizeof (f_hdr)) != sizeof (f_hdr))
669 if (write (new, &f_ohdr, sizeof (f_ohdr)) != sizeof (f_ohdr))
674 #ifndef USG_SHARED_LIBRARIES
676 if (write (new, &f_thdr, sizeof (f_thdr)) != sizeof (f_thdr))
681 if (write (new, &f_dhdr, sizeof (f_dhdr)) != sizeof (f_dhdr))
686 if (write (new, &f_bhdr, sizeof (f_bhdr)) != sizeof (f_bhdr))
691 #else /* USG_SHARED_LIBRARIES */
693 /* The purpose of this code is to write out the new file's section
696 * Scan through the original file's sections. If the encountered
697 * section is one we know (.text, .data or .bss), write out the
698 * correct header. If it is a section we do not know (such as
699 * .lib), adjust the address of where the section data is in the
700 * file, and write out the header.
702 * If any section precedes .text or .data in the file, this code
703 * will not adjust the file pointer for that section correctly.
706 /* This used to use sizeof (f_ohdr) instead of .f_opthdr.
707 .f_opthdr is said to be right when there is no optional header. */
708 lseek (a_out, sizeof (f_hdr) + f_hdr.f_opthdr, 0);
710 for (scns = f_hdr.f_nscns; scns > 0; scns--)
712 if (read (a_out, &scntemp, sizeof (scntemp)) != sizeof (scntemp))
715 if (!strcmp (scntemp.s_name, f_thdr.s_name)) /* .text */
717 if (write (new, &f_thdr, sizeof (f_thdr)) != sizeof (f_thdr))
720 else if (!strcmp (scntemp.s_name, f_dhdr.s_name)) /* .data */
722 if (write (new, &f_dhdr, sizeof (f_dhdr)) != sizeof (f_dhdr))
725 else if (!strcmp (scntemp.s_name, f_bhdr.s_name)) /* .bss */
727 if (write (new, &f_bhdr, sizeof (f_bhdr)) != sizeof (f_bhdr))
732 if (scntemp.s_scnptr)
733 scntemp.s_scnptr += bias;
734 if (write (new, &scntemp, sizeof (scntemp)) != sizeof (scntemp))
738 #endif /* USG_SHARED_LIBRARIES */
742 #else /* if not COFF */
744 /* Get symbol table info from header of a.out file if given one. */
747 #ifdef COFF_ENCAPSULATE
748 if (read (a_out, &coffheader, sizeof coffheader) != sizeof coffheader)
752 if (coffheader.f_magic != COFF_MAGIC)
754 ERROR1("%s doesn't have legal coff magic number\n", a_name);
757 if (read (a_out, (char *) &ohdr, sizeof hdr) != sizeof hdr)
764 ERROR1 ("invalid magic number in %s", a_name);
770 #ifdef COFF_ENCAPSULATE
771 /* We probably could without too much trouble. The code is in gld
772 * but I don't have that much time or incentive.
774 ERROR0 ("can't build a COFF file from scratch yet");
776 memset ((void *)&hdr, 0, sizeof hdr);
780 unexec_text_start = (long) start_of_text ();
781 unexec_data_start = data_start;
783 /* Machine-dependent fixup for header, or maybe for unexec_text_start */
784 #ifdef ADJUST_EXEC_HEADER
786 #endif /* ADJUST_EXEC_HEADER */
790 if (entry_address != 0)
791 hdr.a_entry = entry_address;
793 hdr.a_bss = bss_end - bss_start;
794 hdr.a_data = bss_start - data_start;
796 hdr.a_text = ohdr.a_text;
797 #else /* not NO_REMAP */
798 hdr.a_text = data_start - unexec_text_start;
801 hdr.a_text += A_TEXT_OFFSET (ohdr);
804 #endif /* not NO_REMAP */
806 #ifdef COFF_ENCAPSULATE
807 /* We are encapsulating BSD format within COFF format. */
809 struct coffscn *tp, *dp, *bp;
810 tp = &coffheader.scns[0];
811 dp = &coffheader.scns[1];
812 bp = &coffheader.scns[2];
813 tp->s_size = hdr.a_text + sizeof(struct exec);
814 dp->s_paddr = data_start;
815 dp->s_vaddr = data_start;
816 dp->s_size = hdr.a_data;
817 bp->s_paddr = dp->s_vaddr + dp->s_size;
818 bp->s_vaddr = bp->s_paddr;
819 bp->s_size = hdr.a_bss;
820 coffheader.tsize = tp->s_size;
821 coffheader.dsize = dp->s_size;
822 coffheader.bsize = bp->s_size;
823 coffheader.text_start = tp->s_vaddr;
824 coffheader.data_start = dp->s_vaddr;
826 if (write (new, &coffheader, sizeof coffheader) != sizeof coffheader)
830 #endif /* COFF_ENCAPSULATE */
832 if (write (new, (char *) &hdr, sizeof hdr) != sizeof hdr)
837 #if 0 /* This #ifndef caused a bug on Linux when using QMAGIC. */
838 /* This adjustment was done above only #ifndef NO_REMAP,
839 so only undo it now #ifndef NO_REMAP. */
840 /* #ifndef NO_REMAP */
843 hdr.a_text -= A_TEXT_OFFSET (ohdr);
848 #endif /* not COFF */
851 static void write_segment (int, char *, char *);
853 /* ****************************************************************
856 * Copy the text and data segments from memory to the new a.out
859 copy_text_and_data (int new, int a_out)
866 #ifdef USG_SHARED_LIBRARIES
869 struct scnhdr scntemp; /* Temporary section header */
871 /* The purpose of this code is to write out the new file's section
874 * Step through the section table. If we know the section (.text,
875 * .data) do the appropriate thing. Otherwise, if the section has
876 * no allocated space in the file (.bss), do nothing. Otherwise,
877 * the section has space allocated in the file, and is not a section
878 * we know. So just copy it.
881 lseek (a_out, sizeof (struct filehdr) + sizeof (struct aouthdr), 0);
883 for (scns = f_hdr.f_nscns; scns > 0; scns--)
885 if (read (a_out, &scntemp, sizeof (scntemp)) != sizeof (scntemp))
888 if (!strcmp (scntemp.s_name, ".text"))
890 lseek (new, (long) text_scnptr, 0);
891 ptr = (char *) f_ohdr.text_start;
892 end = ptr + f_ohdr.tsize;
893 write_segment (new, ptr, end);
895 else if (!strcmp (scntemp.s_name, ".data"))
897 lseek (new, (long) data_scnptr, 0);
898 ptr = (char *) f_ohdr.data_start;
899 end = ptr + f_ohdr.dsize;
900 write_segment (new, ptr, end);
902 else if (!scntemp.s_scnptr)
903 ; /* do nothing - no data for this section */
908 long old_a_out_ptr = lseek (a_out, 0, 1);
910 lseek (a_out, scntemp.s_scnptr, 0);
911 for (size = scntemp.s_size; size > 0; size -= sizeof (page))
913 n = size > sizeof (page) ? sizeof (page) : size;
914 if (read (a_out, page, n) != n || write (new, page, n) != n)
917 lseek (a_out, old_a_out_ptr, 0);
921 #else /* COFF, but not USG_SHARED_LIBRARIES */
925 /* Dump the original table of exception handlers, not the one
926 where our exception hooks are registered. */
927 __djgpp_exception_toggle ();
931 lseek (new, (long) text_scnptr, 0);
932 ptr = (char *) f_ohdr.text_start;
933 #ifdef HEADER_INCL_IN_TEXT
934 /* For Gould UTX/32, text starts after headers */
935 ptr = (char *) (ptr + text_scnptr);
936 #endif /* HEADER_INCL_IN_TEXT */
937 end = ptr + f_ohdr.tsize;
938 write_segment (new, ptr, end);
940 lseek (new, (long) data_scnptr, 0);
941 ptr = (char *) f_ohdr.data_start;
942 end = ptr + f_ohdr.dsize;
943 write_segment (new, ptr, end);
947 /* Restore our exception hooks. */
948 __djgpp_exception_toggle ();
952 #endif /* USG_SHARED_LIBRARIES */
954 #else /* if not COFF */
956 /* Some machines count the header as part of the text segment.
957 That is to say, the header appears in core
958 just before the address that start_of_text returns.
959 For them, N_TXTOFF is the place where the header goes.
960 We must adjust the seek to the place after the header.
961 Note that at this point hdr.a_text does *not* count
962 the extra A_TEXT_OFFSET bytes, only the actual bytes of code. */
965 lseek (new, (long) A_TEXT_SEEK (hdr), 0);
967 lseek (new, (long) N_TXTOFF (hdr), 0);
968 #endif /* no A_TEXT_SEEK */
972 /* Acorn's RISC-iX has a wacky way of initializing the position of the heap.
973 * There is a little table in crt0.o that is filled at link time with
974 * the min and current brk positions, among other things. When start
975 * runs, it copies the table to where these parameters live during
976 * execution. This data is in text space, so it cannot be modified here
977 * before saving the executable, so the data is written manually. In
978 * addition, the table does not have a label, and the nearest accessible
979 * label (mcount) is not prefixed with a '_', thus making it inaccessible
980 * from within C programs. To overcome this, emacs's executable is passed
981 * through the command 'nm %s | fgrep mcount' into a pipe, and the
982 * resultant output is then used to find the address of 'mcount'. As far as
983 * is possible to determine, in RISC-iX releases prior to 1.2, the negative
984 * offset of the table from mcount is 0x2c, whereas from 1.2 onwards it is
985 * 0x30. bss_end has been rounded up to page boundary. This solution is
986 * based on suggestions made by Kevin Welton and Steve Hunt of Acorn, and
987 * avoids the need for a custom version of crt0.o for emacs which has its
988 * table in data space.
994 char address_text[32];
999 int mcount_address, mcount_offset, count;
1000 extern char *_execname;
1003 /* The use of _execname is incompatible with RISCiX 1.1 */
1004 sprintf (command, "nm %s | fgrep mcount", _execname);
1006 if ( (pfile = popen(command, "r")) == NULL)
1008 sprintf (errbuf, "Could not open pipe");
1013 while ( ((c=getc(pfile)) != EOF) && (c != ' ') && (count < 31))
1014 address_text[count++]=c;
1015 address_text[count]=0;
1017 if ((count == 0) || pclose(pfile) != NULL)
1019 sprintf (errbuf, "Failed to execute the command '%s'\n", command);
1023 sscanf(address_text, "%x", &mcount_address);
1024 ptr = (char *) unexec_text_start;
1025 mcount_offset = (char *)mcount_address - ptr;
1028 #define EDATA_OFFSET 0x2c
1030 #define EDATA_OFFSET 0x30
1033 end = ptr + mcount_offset - EDATA_OFFSET;
1035 write_segment (new, ptr, end);
1037 proforma[0] = bss_end; /* becomes _edata */
1038 proforma[1] = bss_end; /* becomes _end */
1039 proforma[2] = bss_end; /* becomes _minbrk */
1040 proforma[3] = bss_end; /* becomes _curbrk */
1042 write (new, proforma, 16);
1046 end = temp_ptr + hdr.a_text;
1048 write_segment (new, ptr, end);
1052 ptr = (char *) unexec_text_start;
1053 end = ptr + hdr.a_text;
1054 write_segment (new, ptr, end);
1057 ptr = (char *) unexec_data_start;
1058 end = ptr + hdr.a_data;
1059 /* This lseek is certainly incorrect when A_TEXT_OFFSET
1060 and I believe it is a no-op otherwise.
1061 Let's see if its absence ever fails. */
1062 /* lseek (new, (long) N_TXTOFF (hdr) + hdr.a_text, 0); */
1063 write_segment (new, ptr, end);
1065 #endif /* not COFF */
1071 write_segment (new, ptr, end)
1080 /* This is the normal amount to write at once.
1081 It is the size of block that NFS uses. */
1082 int writesize = 1 << 13;
1083 int pagesize = getpagesize ();
1084 char zeros[1 << 13];
1086 memset (zeros, 0, sizeof (zeros));
1088 for (i = 0; ptr < end;)
1090 /* Distance to next multiple of writesize. */
1091 nwrite = (((int) ptr + writesize) & -writesize) - (int) ptr;
1092 /* But not beyond specified end. */
1093 if (nwrite > end - ptr) nwrite = end - ptr;
1094 ret = write (new, ptr, nwrite);
1095 /* If write gets a page fault, it means we reached
1096 a gap between the old text segment and the old data segment.
1097 This gap has probably been remapped into part of the text segment.
1098 So write zeros for it. */
1105 /* Write only a page of zeros at once,
1106 so that we don't overshoot the start
1107 of the valid memory in the old data segment. */
1108 if (nwrite > pagesize)
1110 write (new, zeros, nwrite);
1112 #if 0 /* Now that we have can ask `write' to write more than a page,
1113 it is legit for write do less than the whole amount specified. */
1114 else if (nwrite != ret)
1117 "unexec write failure: addr 0x%lx, fileno %d, size 0x%x, wrote 0x%x, errno %d",
1118 (unsigned long) ptr, new, nwrite, ret, errno);
1127 /* ****************************************************************
1130 * Copy the relocation information and symbol table from the a.out to the new
1133 copy_sym (int new, int a_out, char *a_name, char *new_name)
1142 if (SYMS_START == 0L)
1147 if (lnnoptr) /* if there is line number info */
1148 lseek (a_out, lnnoptr, 0); /* start copying from there */
1151 lseek (a_out, SYMS_START, 0); /* Position a.out to symtab. */
1153 while ((n = read (a_out, page, sizeof page)) > 0)
1155 if (write (new, page, n) != n)
1167 /* ****************************************************************
1170 * After successfully building the new a.out, mark it executable
1177 int new = 0; /* for PERROR */
1181 if (stat (name, &sbuf) == -1)
1185 sbuf.st_mode |= 0111 & ~um;
1186 if (chmod (name, sbuf.st_mode) == -1)
1191 #ifndef COFF_BSD_SYMBOLS
1194 * If the COFF file contains a symbol table and a line number section,
1195 * then any auxiliary entries that have values for x_lnnoptr must
1196 * be adjusted by the amount that the line number section has moved
1197 * in the file (bias computed in make_hdr). The #@$%&* designers of
1198 * the auxiliary entry structures used the absolute file offsets for
1199 * the line number entry rather than an offset from the start of the
1200 * line number section!
1202 * When I figure out how to scan through the symbol table and pick out
1203 * the auxiliary entries that need adjustment, this routine will
1204 * be fixed. As it is now, all such entries are wrong and sdb
1205 * will complain. Fred Fish, UniSoft Systems Inc.
1208 /* This function is probably very slow. Instead of reopening the new
1209 file for input and output it should copy from the old to the new
1210 using the two descriptors already open (WRITEDESC and READDESC).
1211 Instead of reading one small structure at a time it should use
1212 a reasonable size buffer. But I don't have time to work on such
1213 things, so I am installing it as submitted to me. -- RMS. */
1216 adjust_lnnoptrs (writedesc, readdesc, new_name)
1223 #if defined (amdahl_uts) || defined (pfa)
1227 struct syment symentry;
1228 union auxent auxentry;
1231 if (!lnnoptr || !f_hdr.f_symptr)
1235 if ((new = writedesc) < 0)
1237 if ((new = open (new_name, O_RDWR)) < 0)
1244 lseek (new, f_hdr.f_symptr, 0);
1245 for (nsyms = 0; nsyms < f_hdr.f_nsyms; nsyms++)
1247 read (new, &symentry, SYMESZ);
1248 if (symentry.n_numaux)
1250 read (new, &auxentry, AUXESZ);
1252 if (ISFCN (symentry.n_type) || symentry.n_type == 0x2400)
1254 auxentry.x_sym.x_fcnary.x_fcn.x_lnnoptr += bias;
1255 lseek (new, -AUXESZ, 1);
1256 write (new, &auxentry, AUXESZ);
1266 #endif /* COFF_BSD_SYMBOLS */
1270 #endif /* not CANNOT_DUMP */