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
203 /* I don't understand this, but it's necessary to get some slots in struct exec
204 from /usr/include/sys/exec.h when running LCC in strict ANSI mode. We don't
205 need this in K&R mode...
207 #if defined(__lucid) && defined(__sparc) && !defined(sun)
211 #ifndef CANNOT_DUMP /* all rest of file! */
213 #ifdef COFF_ENCAPSULATE
214 int need_coff_header = 1;
215 #include <coff-encap/a.out.encap.h> /* The location might be a poor assumption */
219 #include <fcntl.h> /* for O_RDONLY, O_RDWR */
222 #define filehdr external_filehdr
223 #define scnhdr external_scnhdr
224 #define syment external_syment
225 #define auxent external_auxent
226 #define n_numaux e_numaux
227 #define n_type e_type
230 unsigned short magic; /* type of file */
231 unsigned short vstamp; /* version stamp */
232 unsigned long tsize; /* text size in bytes, padded to FW bdry*/
233 unsigned long dsize; /* initialized data " " */
234 unsigned long bsize; /* uninitialized data " " */
235 unsigned long entry; /* entry pt. */
236 unsigned long text_start;/* base of text used for this file */
237 unsigned long data_start;/* base of data used for this file */
241 #else /* not MSDOS */
243 #endif /* not MSDOS */
244 #endif /* not COFF_ENCAPSULATE */
246 /* Define getpagesize if the system does not.
247 Note that this may depend on symbols defined in a.out.h. */
248 #include "getpagesize.h"
250 #ifndef makedev /* Try to detect types.h already loaded */
251 #include <sys/types.h>
254 #include <sys/stat.h>
257 #include <sys/file.h> /* Must be after sys/types.h for USG and BSD4_1*/
271 extern char *start_of_text (); /* Start of text */
273 extern void *start_of_data (); /* Start of initialized data */
276 static long block_copy_start; /* Old executable start point */
277 static struct filehdr f_hdr; /* File header */
278 static struct aouthdr f_ohdr; /* Optional file header (a.out) */
279 long bias; /* Bias to add for growth */
280 long lnnoptr; /* Pointer to line-number info within file */
281 #define SYMS_START block_copy_start
283 static long text_scnptr;
284 static long data_scnptr;
289 #ifndef __sys_stdtypes_h
291 typedef long ptrdiff_t;
295 /* not sure where this for NetBSD should really go
296 and it probably applies to other systems */
297 #if !defined(__NetBSD__) && !defined(__bsdi__) && !defined(__OpenBSD__)
298 extern void *sbrk (ptrdiff_t);
300 extern char *sbrk ();
301 #endif /* __NetBSD__ or __OpenBSD__ */
304 extern void *sbrk ();
307 #define SYMS_START ((long) N_SYMOFF (ohdr))
309 /* Some machines override the structure name for an a.out header. */
310 #ifndef EXEC_HDR_TYPE
311 #define EXEC_HDR_TYPE struct exec
316 #define MY_ID HP9000S200_ID
320 #endif /* no HP9000S200_ID */
321 static MAGIC OLDMAGIC = {MY_ID, SHARE_MAGIC};
322 static MAGIC NEWMAGIC = {MY_ID, DEMAND_MAGIC};
323 #define N_TXTOFF(x) TEXT_OFFSET(x)
324 #define N_SYMOFF(x) LESYM_OFFSET(x)
325 static EXEC_HDR_TYPE hdr, ohdr;
329 #if defined (USG) && !defined (IBMAIX) && !defined (IRIS) && !defined (COFF_ENCAPSULATE) && !defined (LINUX)
330 static struct bhdr hdr, ohdr;
331 #define a_magic fmagic
336 #define a_trsize rtsize
337 #define a_drsize rdsize
338 #define a_entry entry
339 #define N_BADMAG(x) \
340 (((x).fmagic)!=OMAGIC && ((x).fmagic)!=NMAGIC &&\
341 ((x).fmagic)!=FMAGIC && ((x).fmagic)!=IMAGIC)
342 #define NEWMAGIC FMAGIC
343 #else /* IRIS or IBMAIX or not USG */
344 static EXEC_HDR_TYPE hdr, ohdr;
345 #define NEWMAGIC ZMAGIC
346 #endif /* IRIS or IBMAIX not USG */
347 #endif /* not HPUX */
349 static int unexec_text_start;
350 static int unexec_data_start;
352 #ifdef COFF_ENCAPSULATE
353 /* coffheader is defined in the GNU a.out.encap.h file. */
354 struct coffheader coffheader;
357 #endif /* not COFF */
361 /* Correct an int which is the bit pattern of a pointer to a byte
362 into an int which is the number of a byte.
363 This is a no-op on ordinary machines, but not on all. */
365 #ifndef ADDR_CORRECT /* Let m-*.h files override this definition */
366 #define ADDR_CORRECT(x) ((char *)(x) - (char*)0)
374 report_error (file, fd)
380 report_file_error ("Cannot unexec",
381 Fcons (build_ext_string (file, FORMAT_FILENAME), Qnil));
385 #define ERROR0(msg) report_error_1 (new, msg, 0, 0); return -1
386 #define ERROR1(msg,x) report_error_1 (new, msg, x, 0); return -1
387 #define ERROR2(msg,x,y) report_error_1 (new, msg, x, y); return -1
390 report_error_1 (fd, msg, a1, a2)
399 fprintf (stderr, msg, a1, a2);
400 fprintf (stderr, "\n");
404 static int make_hdr (int new, int a_out, unsigned data_start,
405 unsigned bss_start, unsigned entry_address,
406 char *a_name, char *new_name);
407 static int copy_text_and_data (int new, int a_out);
408 static int copy_sym (int new, int a_out, char *a_name, char *new_name);
409 static void mark_x (char *name);
411 /* ****************************************************************
417 unexec (new_name, a_name, data_start, bss_start, entry_address)
418 char *new_name, *a_name;
419 unsigned data_start, bss_start, entry_address;
423 if (a_name && (a_out = open (a_name, O_RDONLY)) < 0)
427 if ((new = creat (new_name, 0666)) < 0)
432 if (make_hdr (new, a_out, data_start, bss_start, entry_address, a_name, new_name) < 0
433 || copy_text_and_data (new, a_out) < 0
434 || copy_sym (new, a_out, a_name, new_name) < 0
436 #ifndef COFF_BSD_SYMBOLS
437 || adjust_lnnoptrs (new, a_out, new_name) < 0
443 /* unlink (new_name); / * Failed, unlink new a.out */
454 /* ****************************************************************
457 * Make the header in the new a.out from the header in core.
458 * Modify the text and data sizes.
461 make_hdr (int new, int a_out, unsigned data_start, unsigned bss_start,
462 unsigned entry_address, char *a_name, char *new_name)
465 auto struct scnhdr f_thdr; /* Text section header */
466 auto struct scnhdr f_dhdr; /* Data section header */
467 auto struct scnhdr f_bhdr; /* Bss section header */
468 auto struct scnhdr scntemp; /* Temporary section header */
471 #ifdef USG_SHARED_LIBRARIES
472 extern unsigned int bss_end;
474 unsigned int bss_end;
477 pagemask = getpagesize () - 1;
479 /* Adjust text/data boundary. */
481 data_start = (int) start_of_data ();
482 #else /* not NO_REMAP */
484 data_start = (int) start_of_data ();
485 #endif /* not NO_REMAP */
486 data_start = ADDR_CORRECT (data_start);
489 data_start = data_start & ~SEGMENT_MASK; /* (Down) to segment boundary. */
491 data_start = data_start & ~pagemask; /* (Down) to page boundary. */
494 bss_end = ADDR_CORRECT (sbrk (0)) + pagemask;
495 bss_end &= ~ pagemask;
497 /* Adjust data/bss boundary. */
500 bss_start = (ADDR_CORRECT (bss_start) + pagemask);
501 /* (Up) to page bdry. */
502 bss_start &= ~ pagemask;
503 if (bss_start > bss_end)
505 ERROR1 ("unexec: Specified bss_start (%u) is past end of program",
512 if (data_start > bss_start) /* Can't have negative data size. */
514 ERROR2 ("unexec: data_start (%u) can't be greater than bss_start (%u)",
515 data_start, bss_start);
519 /* Salvage as much info from the existing file as possible */
522 if (read (a_out, &f_hdr, sizeof (f_hdr)) != sizeof (f_hdr))
526 block_copy_start += sizeof (f_hdr);
527 if (f_hdr.f_opthdr > 0)
529 if (read (a_out, &f_ohdr, sizeof (f_ohdr)) != sizeof (f_ohdr))
533 block_copy_start += sizeof (f_ohdr);
535 /* Loop through section headers, copying them in */
536 lseek (a_out, sizeof (f_hdr) + f_hdr.f_opthdr, 0);
537 for (scns = f_hdr.f_nscns; scns > 0; scns--) {
538 if (read (a_out, &scntemp, sizeof (scntemp)) != sizeof (scntemp))
542 if (scntemp.s_scnptr > 0L)
544 if (block_copy_start < scntemp.s_scnptr + scntemp.s_size)
545 block_copy_start = scntemp.s_scnptr + scntemp.s_size;
547 if (strcmp (scntemp.s_name, ".text") == 0)
551 else if (strcmp (scntemp.s_name, ".data") == 0)
555 else if (strcmp (scntemp.s_name, ".bss") == 0)
563 ERROR0 ("can't build a COFF file from scratch yet");
566 /* Now we alter the contents of all the f_*hdr variables
567 to correspond to what we want to dump. */
569 #ifdef USG_SHARED_LIBRARIES
571 /* The amount of data we're adding to the file is distance from the
572 * end of the original .data space to the current end of the .data
576 bias = bss_start - (f_ohdr.data_start + f_dhdr.s_size);
580 f_hdr.f_flags |= (F_RELFLG | F_EXEC);
585 f_ohdr.magic = EXEC_MAGIC;
588 f_ohdr.text_start = (long) start_of_text ();
589 f_ohdr.tsize = data_start - f_ohdr.text_start;
590 f_ohdr.data_start = data_start;
591 #endif /* NO_REMAP */
592 f_ohdr.dsize = bss_start - f_ohdr.data_start;
593 f_ohdr.bsize = bss_end - bss_start;
594 #ifndef KEEP_OLD_TEXT_SCNPTR
595 /* On some machines, the old values are right.
596 ??? Maybe on all machines with NO_REMAP. */
597 f_thdr.s_size = f_ohdr.tsize;
598 f_thdr.s_scnptr = sizeof (f_hdr) + sizeof (f_ohdr);
599 f_thdr.s_scnptr += (f_hdr.f_nscns) * (sizeof (f_thdr));
600 #endif /* KEEP_OLD_TEXT_SCNPTR */
601 #ifdef ADJUST_TEXT_SCNHDR_SIZE
602 /* On some machines, `text size' includes all headers. */
603 f_thdr.s_size -= f_thdr.s_scnptr;
604 #endif /* ADJUST_TEST_SCNHDR_SIZE */
605 lnnoptr = f_thdr.s_lnnoptr;
606 #ifdef SECTION_ALIGNMENT
607 /* Some systems require special alignment
608 of the sections in the file itself. */
610 = (f_thdr.s_scnptr + SECTION_ALIGNMENT) & ~SECTION_ALIGNMENT;
611 #endif /* SECTION_ALIGNMENT */
613 f_thdr.s_scnptr = 0xd0;
615 text_scnptr = f_thdr.s_scnptr;
616 #ifdef ADJUST_TEXTBASE
617 text_scnptr = sizeof (f_hdr) + sizeof (f_ohdr) + (f_hdr.f_nscns) * (sizeof (f_thdr));
619 #ifndef KEEP_OLD_PADDR
620 f_dhdr.s_paddr = f_ohdr.data_start;
621 #endif /* KEEP_OLD_PADDR */
622 f_dhdr.s_vaddr = f_ohdr.data_start;
623 f_dhdr.s_size = f_ohdr.dsize;
624 f_dhdr.s_scnptr = f_thdr.s_scnptr + f_thdr.s_size;
625 #ifdef SECTION_ALIGNMENT
626 /* Some systems require special alignment
627 of the sections in the file itself. */
629 = (f_dhdr.s_scnptr + SECTION_ALIGNMENT) & ~SECTION_ALIGNMENT;
630 #endif /* SECTION_ALIGNMENT */
631 #ifdef DATA_SECTION_ALIGNMENT
632 /* Some systems require special alignment
633 of the data section only. */
635 = (f_dhdr.s_scnptr + DATA_SECTION_ALIGNMENT) & ~DATA_SECTION_ALIGNMENT;
636 #endif /* DATA_SECTION_ALIGNMENT */
637 data_scnptr = f_dhdr.s_scnptr;
638 #ifndef KEEP_OLD_PADDR
639 f_bhdr.s_paddr = f_ohdr.data_start + f_ohdr.dsize;
640 #endif /* KEEP_OLD_PADDR */
641 f_bhdr.s_vaddr = f_ohdr.data_start + f_ohdr.dsize;
642 f_bhdr.s_size = f_ohdr.bsize;
643 f_bhdr.s_scnptr = 0L;
644 #ifndef USG_SHARED_LIBRARIES
645 bias = f_dhdr.s_scnptr + f_dhdr.s_size - block_copy_start;
648 if (f_hdr.f_symptr > 0L)
650 f_hdr.f_symptr += bias;
653 if (f_thdr.s_lnnoptr > 0L)
655 f_thdr.s_lnnoptr += bias;
658 #ifdef ADJUST_EXEC_HEADER
660 #endif /* ADJUST_EXEC_HEADER */
662 if (write (new, &f_hdr, sizeof (f_hdr)) != sizeof (f_hdr))
667 if (write (new, &f_ohdr, sizeof (f_ohdr)) != sizeof (f_ohdr))
672 #ifndef USG_SHARED_LIBRARIES
674 if (write (new, &f_thdr, sizeof (f_thdr)) != sizeof (f_thdr))
679 if (write (new, &f_dhdr, sizeof (f_dhdr)) != sizeof (f_dhdr))
684 if (write (new, &f_bhdr, sizeof (f_bhdr)) != sizeof (f_bhdr))
689 #else /* USG_SHARED_LIBRARIES */
691 /* The purpose of this code is to write out the new file's section
694 * Scan through the original file's sections. If the encountered
695 * section is one we know (.text, .data or .bss), write out the
696 * correct header. If it is a section we do not know (such as
697 * .lib), adjust the address of where the section data is in the
698 * file, and write out the header.
700 * If any section precedes .text or .data in the file, this code
701 * will not adjust the file pointer for that section correctly.
704 /* This used to use sizeof (f_ohdr) instead of .f_opthdr.
705 .f_opthdr is said to be right when there is no optional header. */
706 lseek (a_out, sizeof (f_hdr) + f_hdr.f_opthdr, 0);
708 for (scns = f_hdr.f_nscns; scns > 0; scns--)
710 if (read (a_out, &scntemp, sizeof (scntemp)) != sizeof (scntemp))
713 if (!strcmp (scntemp.s_name, f_thdr.s_name)) /* .text */
715 if (write (new, &f_thdr, sizeof (f_thdr)) != sizeof (f_thdr))
718 else if (!strcmp (scntemp.s_name, f_dhdr.s_name)) /* .data */
720 if (write (new, &f_dhdr, sizeof (f_dhdr)) != sizeof (f_dhdr))
723 else if (!strcmp (scntemp.s_name, f_bhdr.s_name)) /* .bss */
725 if (write (new, &f_bhdr, sizeof (f_bhdr)) != sizeof (f_bhdr))
730 if (scntemp.s_scnptr)
731 scntemp.s_scnptr += bias;
732 if (write (new, &scntemp, sizeof (scntemp)) != sizeof (scntemp))
736 #endif /* USG_SHARED_LIBRARIES */
740 #else /* if not COFF */
742 /* Get symbol table info from header of a.out file if given one. */
745 #ifdef COFF_ENCAPSULATE
746 if (read (a_out, &coffheader, sizeof coffheader) != sizeof coffheader)
750 if (coffheader.f_magic != COFF_MAGIC)
752 ERROR1("%s doesn't have legal coff magic number\n", a_name);
755 if (read (a_out, (char *) &ohdr, sizeof hdr) != sizeof hdr)
762 ERROR1 ("invalid magic number in %s", a_name);
768 #ifdef COFF_ENCAPSULATE
769 /* We probably could without too much trouble. The code is in gld
770 * but I don't have that much time or incentive.
772 ERROR0 ("can't build a COFF file from scratch yet");
774 memset ((void *)&hdr, 0, sizeof hdr);
778 unexec_text_start = (long) start_of_text ();
779 unexec_data_start = data_start;
781 /* Machine-dependent fixup for header, or maybe for unexec_text_start */
782 #ifdef ADJUST_EXEC_HEADER
784 #endif /* ADJUST_EXEC_HEADER */
788 if (entry_address != 0)
789 hdr.a_entry = entry_address;
791 hdr.a_bss = bss_end - bss_start;
792 hdr.a_data = bss_start - data_start;
794 hdr.a_text = ohdr.a_text;
795 #else /* not NO_REMAP */
796 hdr.a_text = data_start - unexec_text_start;
799 hdr.a_text += A_TEXT_OFFSET (ohdr);
802 #endif /* not NO_REMAP */
804 #ifdef COFF_ENCAPSULATE
805 /* We are encapsulating BSD format within COFF format. */
807 struct coffscn *tp, *dp, *bp;
808 tp = &coffheader.scns[0];
809 dp = &coffheader.scns[1];
810 bp = &coffheader.scns[2];
811 tp->s_size = hdr.a_text + sizeof(struct exec);
812 dp->s_paddr = data_start;
813 dp->s_vaddr = data_start;
814 dp->s_size = hdr.a_data;
815 bp->s_paddr = dp->s_vaddr + dp->s_size;
816 bp->s_vaddr = bp->s_paddr;
817 bp->s_size = hdr.a_bss;
818 coffheader.tsize = tp->s_size;
819 coffheader.dsize = dp->s_size;
820 coffheader.bsize = bp->s_size;
821 coffheader.text_start = tp->s_vaddr;
822 coffheader.data_start = dp->s_vaddr;
824 if (write (new, &coffheader, sizeof coffheader) != sizeof coffheader)
828 #endif /* COFF_ENCAPSULATE */
830 if (write (new, (char *) &hdr, sizeof hdr) != sizeof hdr)
835 #if 0 /* This #ifndef caused a bug on Linux when using QMAGIC. */
836 /* This adjustment was done above only #ifndef NO_REMAP,
837 so only undo it now #ifndef NO_REMAP. */
838 /* #ifndef NO_REMAP */
841 hdr.a_text -= A_TEXT_OFFSET (ohdr);
846 #endif /* not COFF */
849 static void write_segment (int, char *, char *);
851 /* ****************************************************************
854 * Copy the text and data segments from memory to the new a.out
857 copy_text_and_data (int new, int a_out)
864 #ifdef USG_SHARED_LIBRARIES
867 struct scnhdr scntemp; /* Temporary section header */
869 /* The purpose of this code is to write out the new file's section
872 * Step through the section table. If we know the section (.text,
873 * .data) do the appropriate thing. Otherwise, if the section has
874 * no allocated space in the file (.bss), do nothing. Otherwise,
875 * the section has space allocated in the file, and is not a section
876 * we know. So just copy it.
879 lseek (a_out, sizeof (struct filehdr) + sizeof (struct aouthdr), 0);
881 for (scns = f_hdr.f_nscns; scns > 0; scns--)
883 if (read (a_out, &scntemp, sizeof (scntemp)) != sizeof (scntemp))
886 if (!strcmp (scntemp.s_name, ".text"))
888 lseek (new, (long) text_scnptr, 0);
889 ptr = (char *) f_ohdr.text_start;
890 end = ptr + f_ohdr.tsize;
891 write_segment (new, ptr, end);
893 else if (!strcmp (scntemp.s_name, ".data"))
895 lseek (new, (long) data_scnptr, 0);
896 ptr = (char *) f_ohdr.data_start;
897 end = ptr + f_ohdr.dsize;
898 write_segment (new, ptr, end);
900 else if (!scntemp.s_scnptr)
901 ; /* do nothing - no data for this section */
906 long old_a_out_ptr = lseek (a_out, 0, 1);
908 lseek (a_out, scntemp.s_scnptr, 0);
909 for (size = scntemp.s_size; size > 0; size -= sizeof (page))
911 n = size > sizeof (page) ? sizeof (page) : size;
912 if (read (a_out, page, n) != n || write (new, page, n) != n)
915 lseek (a_out, old_a_out_ptr, 0);
919 #else /* COFF, but not USG_SHARED_LIBRARIES */
923 /* Dump the original table of exception handlers, not the one
924 where our exception hooks are registered. */
925 __djgpp_exception_toggle ();
929 lseek (new, (long) text_scnptr, 0);
930 ptr = (char *) f_ohdr.text_start;
931 #ifdef HEADER_INCL_IN_TEXT
932 /* For Gould UTX/32, text starts after headers */
933 ptr = (char *) (ptr + text_scnptr);
934 #endif /* HEADER_INCL_IN_TEXT */
935 end = ptr + f_ohdr.tsize;
936 write_segment (new, ptr, end);
938 lseek (new, (long) data_scnptr, 0);
939 ptr = (char *) f_ohdr.data_start;
940 end = ptr + f_ohdr.dsize;
941 write_segment (new, ptr, end);
945 /* Restore our exception hooks. */
946 __djgpp_exception_toggle ();
950 #endif /* USG_SHARED_LIBRARIES */
952 #else /* if not COFF */
954 /* Some machines count the header as part of the text segment.
955 That is to say, the header appears in core
956 just before the address that start_of_text returns.
957 For them, N_TXTOFF is the place where the header goes.
958 We must adjust the seek to the place after the header.
959 Note that at this point hdr.a_text does *not* count
960 the extra A_TEXT_OFFSET bytes, only the actual bytes of code. */
963 lseek (new, (long) A_TEXT_SEEK (hdr), 0);
965 lseek (new, (long) N_TXTOFF (hdr), 0);
966 #endif /* no A_TEXT_SEEK */
970 /* Acorn's RISC-iX has a wacky way of initialising the position of the heap.
971 * There is a little table in crt0.o that is filled at link time with
972 * the min and current brk positions, among other things. When start
973 * runs, it copies the table to where these parameters live during
974 * execution. This data is in text space, so it cannot be modified here
975 * before saving the executable, so the data is written manually. In
976 * addition, the table does not have a label, and the nearest accessible
977 * label (mcount) is not prefixed with a '_', thus making it inaccessible
978 * from within C programs. To overcome this, emacs's executable is passed
979 * through the command 'nm %s | fgrep mcount' into a pipe, and the
980 * resultant output is then used to find the address of 'mcount'. As far as
981 * is possible to determine, in RISC-iX releases prior to 1.2, the negative
982 * offset of the table from mcount is 0x2c, whereas from 1.2 onwards it is
983 * 0x30. bss_end has been rounded up to page boundary. This solution is
984 * based on suggestions made by Kevin Welton and Steve Hunt of Acorn, and
985 * avoids the need for a custom version of crt0.o for emacs which has its
986 * table in data space.
992 char address_text[32];
997 int mcount_address, mcount_offset, count;
998 extern char *_execname;
1001 /* The use of _execname is incompatible with RISCiX 1.1 */
1002 sprintf (command, "nm %s | fgrep mcount", _execname);
1004 if ( (pfile = popen(command, "r")) == NULL)
1006 sprintf (errbuf, "Could not open pipe");
1011 while ( ((c=getc(pfile)) != EOF) && (c != ' ') && (count < 31))
1012 address_text[count++]=c;
1013 address_text[count]=0;
1015 if ((count == 0) || pclose(pfile) != NULL)
1017 sprintf (errbuf, "Failed to execute the command '%s'\n", command);
1021 sscanf(address_text, "%x", &mcount_address);
1022 ptr = (char *) unexec_text_start;
1023 mcount_offset = (char *)mcount_address - ptr;
1026 #define EDATA_OFFSET 0x2c
1028 #define EDATA_OFFSET 0x30
1031 end = ptr + mcount_offset - EDATA_OFFSET;
1033 write_segment (new, ptr, end);
1035 proforma[0] = bss_end; /* becomes _edata */
1036 proforma[1] = bss_end; /* becomes _end */
1037 proforma[2] = bss_end; /* becomes _minbrk */
1038 proforma[3] = bss_end; /* becomes _curbrk */
1040 write (new, proforma, 16);
1044 end = temp_ptr + hdr.a_text;
1046 write_segment (new, ptr, end);
1050 ptr = (char *) unexec_text_start;
1051 end = ptr + hdr.a_text;
1052 write_segment (new, ptr, end);
1055 ptr = (char *) unexec_data_start;
1056 end = ptr + hdr.a_data;
1057 /* This lseek is certainly incorrect when A_TEXT_OFFSET
1058 and I believe it is a no-op otherwise.
1059 Let's see if its absence ever fails. */
1060 /* lseek (new, (long) N_TXTOFF (hdr) + hdr.a_text, 0); */
1061 write_segment (new, ptr, end);
1063 #endif /* not COFF */
1069 write_segment (new, ptr, end)
1078 /* This is the normal amount to write at once.
1079 It is the size of block that NFS uses. */
1080 int writesize = 1 << 13;
1081 int pagesize = getpagesize ();
1082 char zeros[1 << 13];
1084 memset (zeros, 0, sizeof (zeros));
1086 for (i = 0; ptr < end;)
1088 /* Distance to next multiple of writesize. */
1089 nwrite = (((int) ptr + writesize) & -writesize) - (int) ptr;
1090 /* But not beyond specified end. */
1091 if (nwrite > end - ptr) nwrite = end - ptr;
1092 ret = write (new, ptr, nwrite);
1093 /* If write gets a page fault, it means we reached
1094 a gap between the old text segment and the old data segment.
1095 This gap has probably been remapped into part of the text segment.
1096 So write zeros for it. */
1103 /* Write only a page of zeros at once,
1104 so that we don't overshoot the start
1105 of the valid memory in the old data segment. */
1106 if (nwrite > pagesize)
1108 write (new, zeros, nwrite);
1110 #if 0 /* Now that we have can ask `write' to write more than a page,
1111 it is legit for write do less than the whole amount specified. */
1112 else if (nwrite != ret)
1115 "unexec write failure: addr 0x%lx, fileno %d, size 0x%x, wrote 0x%x, errno %d",
1116 (unsigned long) ptr, new, nwrite, ret, errno);
1125 /* ****************************************************************
1128 * Copy the relocation information and symbol table from the a.out to the new
1131 copy_sym (int new, int a_out, char *a_name, char *new_name)
1140 if (SYMS_START == 0L)
1145 if (lnnoptr) /* if there is line number info */
1146 lseek (a_out, lnnoptr, 0); /* start copying from there */
1149 lseek (a_out, SYMS_START, 0); /* Position a.out to symtab. */
1151 while ((n = read (a_out, page, sizeof page)) > 0)
1153 if (write (new, page, n) != n)
1165 /* ****************************************************************
1168 * After successfully building the new a.out, mark it executable
1175 int new = 0; /* for PERROR */
1179 if (stat (name, &sbuf) == -1)
1183 sbuf.st_mode |= 0111 & ~um;
1184 if (chmod (name, sbuf.st_mode) == -1)
1189 #ifndef COFF_BSD_SYMBOLS
1192 * If the COFF file contains a symbol table and a line number section,
1193 * then any auxiliary entries that have values for x_lnnoptr must
1194 * be adjusted by the amount that the line number section has moved
1195 * in the file (bias computed in make_hdr). The #@$%&* designers of
1196 * the auxiliary entry structures used the absolute file offsets for
1197 * the line number entry rather than an offset from the start of the
1198 * line number section!
1200 * When I figure out how to scan through the symbol table and pick out
1201 * the auxiliary entries that need adjustment, this routine will
1202 * be fixed. As it is now, all such entries are wrong and sdb
1203 * will complain. Fred Fish, UniSoft Systems Inc.
1206 /* This function is probably very slow. Instead of reopening the new
1207 file for input and output it should copy from the old to the new
1208 using the two descriptors already open (WRITEDESC and READDESC).
1209 Instead of reading one small structure at a time it should use
1210 a reasonable size buffer. But I don't have time to work on such
1211 things, so I am installing it as submitted to me. -- RMS. */
1214 adjust_lnnoptrs (writedesc, readdesc, new_name)
1221 #if defined (amdahl_uts) || defined (pfa)
1225 struct syment symentry;
1226 union auxent auxentry;
1229 if (!lnnoptr || !f_hdr.f_symptr)
1233 if ((new = writedesc) < 0)
1235 if ((new = open (new_name, O_RDWR)) < 0)
1242 lseek (new, f_hdr.f_symptr, 0);
1243 for (nsyms = 0; nsyms < f_hdr.f_nsyms; nsyms++)
1245 read (new, &symentry, SYMESZ);
1246 if (symentry.n_numaux)
1248 read (new, &auxentry, AUXESZ);
1250 if (ISFCN (symentry.n_type) || symentry.n_type == 0x2400)
1252 auxentry.x_sym.x_fcnary.x_fcn.x_lnnoptr += bias;
1253 lseek (new, -AUXESZ, 1);
1254 write (new, &auxentry, AUXESZ);
1264 #endif /* COFF_BSD_SYMBOLS */
1268 #endif /* not CANNOT_DUMP */