1 /* Unexec for DEC alpha. schoepf@sc.ZIB-Berlin.DE (Rainer Schoepf).
3 Copyright (C) 1994 Free Software Foundation, Inc.
5 This file is part of GNU Emacs.
7 GNU Emacs is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
12 GNU Emacs is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GNU Emacs; see the file COPYING. If not, write to
19 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
23 #include <sys/types.h>
34 static void fatal_unexec ();
35 static void mark_x ();
37 #define READ(_fd, _buffer, _size, _error_message, _error_arg) \
39 if (read (_fd, _buffer, _size) != _size) \
40 fatal_unexec (_error_message, _error_arg);
42 #define WRITE(_fd, _buffer, _size, _error_message, _error_arg) \
43 if (write (_fd, _buffer, _size) != _size) \
44 fatal_unexec (_error_message, _error_arg);
46 #define SEEK(_fd, _position, _error_message, _error_arg) \
48 if (lseek (_fd, _position, L_SET) != _position) \
49 fatal_unexec (_error_message, _error_arg);
52 extern char *strerror ();
58 static struct scnhdr
*text_section
;
59 static struct scnhdr
*init_section
;
60 static struct scnhdr
*finit_section
;
61 static struct scnhdr
*rdata_section
;
62 static struct scnhdr
*data_section
;
63 static struct scnhdr
*pdata_section
;
64 static struct scnhdr
*xdata_section
;
65 static struct scnhdr
*got_section
;
66 static struct scnhdr
*lit8_section
;
67 static struct scnhdr
*lit4_section
;
68 static struct scnhdr
*sdata_section
;
69 static struct scnhdr
*sbss_section
;
70 static struct scnhdr
*bss_section
;
72 static unsigned int Brk
;
77 struct scnhdr section
[_MIPS_NSCNS_MAX
];
82 /* Define name of label for entry point for the dumped executable. */
84 #ifndef DEFAULT_ENTRY_ADDRESS
85 #define DEFAULT_ENTRY_ADDRESS __start
88 unexec (new_name
, a_name
, data_start
, bss_start
, entry_address
)
89 char *new_name
, *a_name
;
90 unsigned long data_start
, bss_start
, entry_address
;
94 struct headers ohdr
, nhdr
;
102 char buffer
[BUFSIZE
];
104 if ((old
= open (a_name
, O_RDONLY
)) < 0)
105 fatal_unexec ("opening %s", a_name
);
107 new = creat (new_name
, 0666);
108 if (new < 0) fatal_unexec ("creating %s", new_name
);
110 if ((fstat (old
, &stat
) == -1))
111 fatal_unexec ("fstat %s", a_name
);
113 oldptr
= (char *)mmap (0, stat
.st_size
, PROT_READ
, MAP_FILE
|MAP_SHARED
, old
, 0);
115 if (oldptr
== (char *)-1)
116 fatal_unexec ("mmap %s", a_name
);
120 /* This is a copy of the a.out header of the original executable */
122 ohdr
= (*(struct headers
*)oldptr
);
124 /* This is where we build the new header from the in-memory copy */
126 nhdr
= *((struct headers
*)TEXT_START
);
128 /* First do some consistency checks */
130 if (nhdr
.fhdr
.f_magic
!= ALPHAMAGIC
131 && nhdr
.fhdr
.f_magic
!= ALPHAUMAGIC
)
133 fprintf (stderr
, "unexec: input file magic number is %x, not %x or %x.\n",
134 nhdr
.fhdr
.f_magic
, ALPHAMAGIC
, ALPHAUMAGIC
);
138 if (nhdr
.fhdr
.f_opthdr
!= sizeof (nhdr
.aout
))
140 fprintf (stderr
, "unexec: input a.out header is %d bytes, not %d.\n",
141 nhdr
.fhdr
.f_opthdr
, sizeof (nhdr
.aout
));
144 if (nhdr
.aout
.magic
!= ZMAGIC
)
146 fprintf (stderr
, "unexec: input file a.out magic number is %o, not %o.\n",
147 nhdr
.aout
.magic
, ZMAGIC
);
152 /* Now check the existence of certain header section and grab
155 #define CHECK_SCNHDR(ptr, name, flags) \
157 for (i = 0; i < nhdr.fhdr.f_nscns && !ptr; i++) \
158 if (strcmp (nhdr.section[i].s_name, name) == 0) \
160 if (nhdr.section[i].s_flags != flags) \
161 fprintf (stderr, "unexec: %x flags (%x expected) in %s section.\n", \
162 nhdr.section[i].s_flags, flags, name); \
163 ptr = nhdr.section + i; \
166 CHECK_SCNHDR (text_section, _TEXT, STYP_TEXT);
167 CHECK_SCNHDR (init_section
, _INIT
, STYP_INIT
);
169 CHECK_SCNHDR (finit_section
, _FINI
, STYP_FINI
);
171 CHECK_SCNHDR (rdata_section
, _RDATA
, STYP_RDATA
);
173 CHECK_SCNHDR (pdata_section
, _PDATA
, STYP_PDATA
);
176 CHECK_SCNHDR (got_section
, _GOT
, STYP_GOT
);
178 CHECK_SCNHDR (data_section
, _DATA
, STYP_DATA
);
180 CHECK_SCNHDR (xdata_section
, _XDATA
, STYP_XDATA
);
183 CHECK_SCNHDR (lit8_section
, _LIT8
, STYP_LIT8
);
184 CHECK_SCNHDR (lit4_section
, _LIT4
, STYP_LIT4
);
186 CHECK_SCNHDR (sdata_section
, _SDATA
, STYP_SDATA
);
187 CHECK_SCNHDR (sbss_section
, _SBSS
, STYP_SBSS
);
188 CHECK_SCNHDR (bss_section
, _BSS
, STYP_BSS
);
189 #if 0 /* Apparently this error check goes off on irix 3.3,
190 but it doesn't indicate a real problem. */
191 if (i
!= nhdr
.fhdr
.f_nscns
)
192 fprintf (stderr
, "unexec: %d sections found instead of %d.\n",
193 i
, nhdr
.fhdr
.f_nscns
);
197 pagesize
= getpagesize ();
198 brk
= (((long) (sbrk (0))) + pagesize
- 1) & (-pagesize
);
200 /* Remember the current break */
204 nhdr
.aout
.dsize
= brk
- DATA_START
;
206 if (entry_address
== 0)
208 extern DEFAULT_ENTRY_ADDRESS ();
209 nhdr
.aout
.entry
= (unsigned long)DEFAULT_ENTRY_ADDRESS
;
212 nhdr
.aout
.entry
= entry_address
;
214 nhdr
.aout
.bss_start
= nhdr
.aout
.data_start
+ nhdr
.aout
.dsize
;
215 rdata_section
->s_size
= data_start
- DATA_START
;
217 /* Adjust start and virtual addresses of rdata_section, too. */
218 rdata_section
->s_vaddr
= DATA_START
;
219 rdata_section
->s_paddr
= DATA_START
;
220 rdata_section
->s_scnptr
= text_section
->s_scnptr
+ nhdr
.aout
.tsize
;
222 data_section
->s_vaddr
= data_start
;
223 data_section
->s_paddr
= data_start
;
224 data_section
->s_size
= brk
- data_start
;
225 data_section
->s_scnptr
= rdata_section
->s_scnptr
+ rdata_section
->s_size
;
226 vaddr
= data_section
->s_vaddr
+ data_section
->s_size
;
227 scnptr
= data_section
->s_scnptr
+ data_section
->s_size
;
228 if (lit8_section
!= NULL
)
230 lit8_section
->s_vaddr
= vaddr
;
231 lit8_section
->s_paddr
= vaddr
;
232 lit8_section
->s_size
= 0;
233 lit8_section
->s_scnptr
= scnptr
;
235 if (lit4_section
!= NULL
)
237 lit4_section
->s_vaddr
= vaddr
;
238 lit4_section
->s_paddr
= vaddr
;
239 lit4_section
->s_size
= 0;
240 lit4_section
->s_scnptr
= scnptr
;
242 if (sdata_section
!= NULL
)
244 sdata_section
->s_vaddr
= vaddr
;
245 sdata_section
->s_paddr
= vaddr
;
246 sdata_section
->s_size
= 0;
247 sdata_section
->s_scnptr
= scnptr
;
250 if (xdata_section
!= NULL
)
252 xdata_section
->s_vaddr
= vaddr
;
253 xdata_section
->s_paddr
= vaddr
;
254 xdata_section
->s_size
= 0;
255 xdata_section
->s_scnptr
= scnptr
;
259 if (got_section
!= NULL
)
261 got_section
->s_vaddr
= vaddr
;
262 got_section
->s_paddr
= vaddr
;
263 got_section
->s_size
= 0;
264 got_section
->s_scnptr
= scnptr
;
267 if (sbss_section
!= NULL
)
269 sbss_section
->s_vaddr
= vaddr
;
270 sbss_section
->s_paddr
= vaddr
;
271 sbss_section
->s_size
= 0;
272 sbss_section
->s_scnptr
= scnptr
;
274 if (bss_section
!= NULL
)
276 bss_section
->s_vaddr
= vaddr
;
277 bss_section
->s_paddr
= vaddr
;
278 bss_section
->s_size
= 0;
279 bss_section
->s_scnptr
= scnptr
;
282 WRITE (new, (char *)TEXT_START
, nhdr
.aout
.tsize
,
283 "writing text section to %s", new_name
);
284 WRITE (new, (char *)DATA_START
, nhdr
.aout
.dsize
,
285 "writing data section to %s", new_name
);
289 * Construct new symbol table header
292 bcopy (oldptr
+ nhdr
.fhdr
.f_symptr
, buffer
, cbHDRR
);
294 #define symhdr ((pHDRR)buffer)
295 newsyms
= nhdr
.aout
.tsize
+ nhdr
.aout
.dsize
;
296 symrel
= newsyms
- nhdr
.fhdr
.f_symptr
;
297 nhdr
.fhdr
.f_symptr
= newsyms
;
298 symhdr
->cbLineOffset
+= symrel
;
299 symhdr
->cbDnOffset
+= symrel
;
300 symhdr
->cbPdOffset
+= symrel
;
301 symhdr
->cbSymOffset
+= symrel
;
302 symhdr
->cbOptOffset
+= symrel
;
303 symhdr
->cbAuxOffset
+= symrel
;
304 symhdr
->cbSsOffset
+= symrel
;
305 symhdr
->cbSsExtOffset
+= symrel
;
306 symhdr
->cbFdOffset
+= symrel
;
307 symhdr
->cbRfdOffset
+= symrel
;
308 symhdr
->cbExtOffset
+= symrel
;
310 WRITE (new, buffer
, cbHDRR
, "writing symbol table header of %s", new_name
);
313 * Copy the symbol table and line numbers
315 WRITE (new, oldptr
+ ohdr
.fhdr
.f_symptr
+ cbHDRR
,
316 stat
.st_size
- ohdr
.fhdr
.f_symptr
- cbHDRR
,
317 "writing symbol table of %s", new_name
);
321 /* Not needed for now */
323 update_dynamic_symbols (oldptr
, new, newsyms
,
324 ((pHDRR
) (oldptr
+ ohdr
.fhdr
.f_symptr
))->issExtMax
,
325 ((pHDRR
) (oldptr
+ ohdr
.fhdr
.f_symptr
))->cbExtOffset
,
326 ((pHDRR
) (oldptr
+ ohdr
.fhdr
.f_symptr
))->cbSsExtOffset
);
332 SEEK (new, 0, "seeking to start of header in %s", new_name
);
333 WRITE (new, &nhdr
, sizeof (nhdr
),
334 "writing header of %s", new_name
);
344 /* Not needed for now */
346 /* The following function updates the values of some symbols
347 that are used by the dynamic loader:
355 update_dynamic_symbols (old
, new, newsyms
, nsyms
, symoff
, stroff
)
356 char *old
; /* Pointer to old executable */
357 int new; /* File descriptor for new executable */
358 long newsyms
; /* Offset of Symbol table in new executable */
359 int nsyms
; /* Number of symbol table entries */
360 long symoff
; /* Offset of External Symbols in old file */
361 long stroff
; /* Offset of string table in old file */
367 /* We go through the symbol table entries until we have found the two
370 /* cbEXTR is the size of an external symbol table entry */
372 for (i
= 0; i
< nsyms
&& found
< 2; i
+= cbEXTR
)
374 register pEXTR x
= (pEXTR
) (old
+ symoff
+ i
);
377 s
= old
+ stroff
+ x
->asym
.iss
; /* name of the symbol */
379 if (!strcmp(s
,"_edata"))
382 bcopy (x
, &n_edata
, cbEXTR
);
383 n_edata
.asym
.value
= Brk
;
384 SEEK (new, newsyms
+ cbHDRR
+ i
,
385 "seeking to symbol _edata in %s", new_name
);
386 WRITE (new, n_edata
, cbEXTR
,
387 "writing symbol table entry for _edata into %s", new_name
);
389 else if (!strcmp(s
,"_end"))
392 bcopy (x
, &n_end
, cbEXTR
);
393 n_end
.asym
.value
= Brk
;
394 SEEK (new, newsyms
+ cbHDRR
+ i
,
395 "seeking to symbol _end in %s", new_name
);
396 WRITE (new, n_end
, cbEXTR
,
397 "writing symbol table entry for _end into %s", new_name
);
409 * After successfully building the new a.out, mark it executable
417 int um
= umask (777);
419 if (stat (name
, &sbuf
) < 0)
420 fatal_unexec ("getting protection on %s", name
);
421 sbuf
.st_mode
|= 0111 & ~um
;
422 if (chmod (name
, sbuf
.st_mode
) < 0)
423 fatal_unexec ("setting protection on %s", name
);
427 fatal_unexec (s
, va_alist
)
432 fputs ("unexec: unexpected end of file, ", stderr
);
434 fprintf (stderr
, "unexec: %s, ", strerror (errno
));
436 _doprnt (s
, ap
, stderr
);
437 fputs (".\n", stderr
);