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, Inc., 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
22 /* Synched up with: FSF 19.31. */
29 #include <sys/types.h>
41 static void fatal_unexec (char *, char *);
42 static void mark_x (char *);
44 #define READ(_fd, _buffer, _size, _error_message, _error_arg) \
46 if (read (_fd, _buffer, _size) != _size) \
47 fatal_unexec (_error_message, _error_arg);
49 #define WRITE(_fd, _buffer, _size, _error_message, _error_arg) \
50 if (write (_fd, _buffer, _size) != _size) \
51 fatal_unexec (_error_message, _error_arg);
53 #define SEEK(_fd, _position, _error_message, _error_arg) \
55 if (lseek (_fd, _position, L_SET) != _position) \
56 fatal_unexec (_error_message, _error_arg);
62 static struct scnhdr *text_section;
63 static struct scnhdr *init_section;
64 static struct scnhdr *finit_section;
65 static struct scnhdr *rdata_section;
66 static struct scnhdr *rconst_section;
67 static struct scnhdr *data_section;
68 static struct scnhdr *pdata_section;
69 static struct scnhdr *xdata_section;
70 static struct scnhdr *got_section;
71 static struct scnhdr *lit8_section;
72 static struct scnhdr *lit4_section;
73 static struct scnhdr *sdata_section;
74 static struct scnhdr *sbss_section;
75 static struct scnhdr *bss_section;
77 static unsigned long Brk;
82 struct scnhdr section[_MIPS_NSCNS_MAX];
87 /* Define name of label for entry point for the dumped executable. */
89 #ifndef DEFAULT_ENTRY_ADDRESS
90 #define DEFAULT_ENTRY_ADDRESS __start
94 unexec (char *new_name, char *a_name,
95 unsigned long data_start,
96 unsigned long bss_start,
97 unsigned long entry_address)
101 struct headers ohdr, nhdr;
104 long newsyms, symrel;
108 char buffer[BUFSIZE];
110 if ((old = open (a_name, O_RDONLY)) < 0)
111 fatal_unexec ("opening %s", a_name);
113 new = creat (new_name, 0666);
114 if (new < 0) fatal_unexec ("creating %s", new_name);
116 if ((fstat (old, &stat) == -1))
117 fatal_unexec ("fstat %s", a_name);
119 oldptr = (char *)mmap (0, stat.st_size, PROT_READ, MAP_FILE|MAP_SHARED, old, 0);
121 if (oldptr == (char *)-1)
122 fatal_unexec ("mmap %s", a_name);
126 /* This is a copy of the a.out header of the original executable */
128 ohdr = (*(struct headers *)oldptr);
130 /* This is where we build the new header from the in-memory copy */
132 nhdr = *((struct headers *)TEXT_START);
134 /* First do some consistency checks */
136 if (nhdr.fhdr.f_magic != ALPHAMAGIC
137 && nhdr.fhdr.f_magic != ALPHAUMAGIC)
139 fprintf (stderr, "unexec: input file magic number is %x, not %x or %x.\n",
140 nhdr.fhdr.f_magic, ALPHAMAGIC, ALPHAUMAGIC);
144 if (nhdr.fhdr.f_opthdr != sizeof (nhdr.aout))
146 fprintf (stderr, "unexec: input a.out header is %d bytes, not %ld.\n",
147 nhdr.fhdr.f_opthdr, (long) (sizeof (nhdr.aout)));
150 if (nhdr.aout.magic != ZMAGIC)
152 fprintf (stderr, "unexec: input file a.out magic number is %o, not %o.\n",
153 nhdr.aout.magic, ZMAGIC);
158 /* Now check the existence of certain header section and grab
161 #define CHECK_SCNHDR(ptr, name, flags) \
163 for (i = 0; i < nhdr.fhdr.f_nscns && !ptr; i++) \
164 if (strcmp (nhdr.section[i].s_name, name) == 0) \
166 if (nhdr.section[i].s_flags != flags) \
167 fprintf (stderr, "unexec: %x flags (%x expected) in %s section.\n", \
168 nhdr.section[i].s_flags, flags, name); \
169 ptr = nhdr.section + i; \
172 CHECK_SCNHDR (text_section, _TEXT, STYP_TEXT);
173 CHECK_SCNHDR (init_section, _INIT, STYP_INIT);
175 CHECK_SCNHDR (finit_section, _FINI, STYP_FINI);
177 CHECK_SCNHDR (rdata_section, _RDATA, STYP_RDATA);
179 CHECK_SCNHDR (rconst_section, _RCONST, STYP_RCONST);
182 CHECK_SCNHDR (pdata_section, _PDATA, STYP_PDATA);
185 CHECK_SCNHDR (got_section, _GOT, STYP_GOT);
187 CHECK_SCNHDR (data_section, _DATA, STYP_DATA);
189 CHECK_SCNHDR (xdata_section, _XDATA, STYP_XDATA);
192 CHECK_SCNHDR (lit8_section, _LIT8, STYP_LIT8);
193 CHECK_SCNHDR (lit4_section, _LIT4, STYP_LIT4);
195 CHECK_SCNHDR (sdata_section, _SDATA, STYP_SDATA);
196 CHECK_SCNHDR (sbss_section, _SBSS, STYP_SBSS);
197 CHECK_SCNHDR (bss_section, _BSS, STYP_BSS);
200 pagesize = getpagesize ();
201 brk = (((long) (sbrk (0))) + pagesize - 1) & (-pagesize);
203 /* Remember the current break */
207 nhdr.aout.dsize = brk - DATA_START;
209 if (entry_address == 0)
211 extern int DEFAULT_ENTRY_ADDRESS (void);
212 nhdr.aout.entry = (unsigned long)DEFAULT_ENTRY_ADDRESS;
215 nhdr.aout.entry = entry_address;
217 nhdr.aout.bss_start = nhdr.aout.data_start + nhdr.aout.dsize;
219 if (rdata_section != NULL)
221 rdata_section->s_size = data_start - DATA_START;
223 /* Adjust start and virtual addresses of rdata_section, too. */
224 rdata_section->s_vaddr = DATA_START;
225 rdata_section->s_paddr = DATA_START;
226 rdata_section->s_scnptr = text_section->s_scnptr + nhdr.aout.tsize;
229 data_section->s_vaddr = data_start;
230 data_section->s_paddr = data_start;
231 data_section->s_size = brk - data_start;
233 if (rdata_section != NULL)
235 data_section->s_scnptr = rdata_section->s_scnptr + rdata_section->s_size;
238 vaddr = data_section->s_vaddr + data_section->s_size;
239 scnptr = data_section->s_scnptr + data_section->s_size;
240 if (lit8_section != NULL)
242 lit8_section->s_vaddr = vaddr;
243 lit8_section->s_paddr = vaddr;
244 lit8_section->s_size = 0;
245 lit8_section->s_scnptr = scnptr;
247 if (lit4_section != NULL)
249 lit4_section->s_vaddr = vaddr;
250 lit4_section->s_paddr = vaddr;
251 lit4_section->s_size = 0;
252 lit4_section->s_scnptr = scnptr;
254 if (sdata_section != NULL)
256 sdata_section->s_vaddr = vaddr;
257 sdata_section->s_paddr = vaddr;
258 sdata_section->s_size = 0;
259 sdata_section->s_scnptr = scnptr;
262 if (xdata_section != NULL)
264 xdata_section->s_vaddr = vaddr;
265 xdata_section->s_paddr = vaddr;
266 xdata_section->s_size = 0;
267 xdata_section->s_scnptr = scnptr;
271 if (got_section != NULL)
273 got_section->s_vaddr = vaddr;
274 got_section->s_paddr = vaddr;
275 got_section->s_size = 0;
276 got_section->s_scnptr = scnptr;
279 if (sbss_section != NULL)
281 sbss_section->s_vaddr = vaddr;
282 sbss_section->s_paddr = vaddr;
283 sbss_section->s_size = 0;
284 sbss_section->s_scnptr = scnptr;
286 if (bss_section != NULL)
288 bss_section->s_vaddr = vaddr;
289 bss_section->s_paddr = vaddr;
290 bss_section->s_size = 0;
291 bss_section->s_scnptr = scnptr;
294 WRITE (new, (char *)TEXT_START, nhdr.aout.tsize,
295 "writing text section to %s", new_name);
296 WRITE (new, (char *)DATA_START, nhdr.aout.dsize,
297 "writing data section to %s", new_name);
301 * Construct new symbol table header
304 memcpy (buffer, oldptr + nhdr.fhdr.f_symptr, cbHDRR);
306 #define symhdr ((pHDRR)buffer)
307 newsyms = nhdr.aout.tsize + nhdr.aout.dsize;
308 symrel = newsyms - nhdr.fhdr.f_symptr;
309 nhdr.fhdr.f_symptr = newsyms;
310 symhdr->cbLineOffset += symrel;
311 symhdr->cbDnOffset += symrel;
312 symhdr->cbPdOffset += symrel;
313 symhdr->cbSymOffset += symrel;
314 symhdr->cbOptOffset += symrel;
315 symhdr->cbAuxOffset += symrel;
316 symhdr->cbSsOffset += symrel;
317 symhdr->cbSsExtOffset += symrel;
318 symhdr->cbFdOffset += symrel;
319 symhdr->cbRfdOffset += symrel;
320 symhdr->cbExtOffset += symrel;
322 WRITE (new, buffer, cbHDRR, "writing symbol table header of %s", new_name);
325 * Copy the symbol table and line numbers
327 WRITE (new, oldptr + ohdr.fhdr.f_symptr + cbHDRR,
328 stat.st_size - ohdr.fhdr.f_symptr - cbHDRR,
329 "writing symbol table of %s", new_name);
333 /* Not needed for now */
335 update_dynamic_symbols (oldptr, new_name, new, newsyms,
336 ((pHDRR) (oldptr + ohdr.fhdr.f_symptr))->issExtMax,
337 ((pHDRR) (oldptr + ohdr.fhdr.f_symptr))->cbExtOffset,
338 ((pHDRR) (oldptr + ohdr.fhdr.f_symptr))->cbSsExtOffset);
344 SEEK (new, 0, "seeking to start of header in %s", new_name);
345 WRITE (new, &nhdr, sizeof (nhdr),
346 "writing header of %s", new_name);
357 /* Not needed for now */
359 /* The following function updates the values of some symbols
360 that are used by the dynamic loader:
368 update_dynamic_symbols (
369 char *old, /* Pointer to old executable */
370 char *new_name, /* Name of new executable */
371 int new, /* File descriptor for new executable */
372 long newsyms, /* Offset of Symbol table in new executable */
373 int nsyms, /* Number of symbol table entries */
374 long symoff, /* Offset of External Symbols in old file */
375 long stroff) /* Offset of string table in old file */
381 /* We go through the symbol table entries until we have found the two
384 /* cbEXTR is the size of an external symbol table entry */
386 for (i = 0; i < nsyms && found < 2; i += cbEXTR)
388 REGISTER pEXTR x = (pEXTR) (old + symoff + i);
391 s = old + stroff + x->asym.iss; /* name of the symbol */
393 if (!strcmp(s,"_edata"))
396 memcpy (&n_edata, x, cbEXTR);
397 n_edata.asym.value = Brk;
398 SEEK (new, newsyms + cbHDRR + i,
399 "seeking to symbol _edata in %s", new_name);
400 WRITE (new, &n_edata, cbEXTR,
401 "writing symbol table entry for _edata into %s", new_name);
403 else if (!strcmp(s,"_end"))
406 memcpy (&n_end, x, cbEXTR);
407 n_end.asym.value = Brk;
408 SEEK (new, newsyms + cbHDRR + i,
409 "seeking to symbol _end in %s", new_name);
410 WRITE (new, &n_end, cbEXTR,
411 "writing symbol table entry for _end into %s", new_name);
423 * After successfully building the new a.out, mark it executable
430 int um = umask (777);
432 if (stat (name, &sbuf) < 0)
433 fatal_unexec ("getting protection on %s", name);
434 sbuf.st_mode |= 0111 & ~um;
435 if (chmod (name, sbuf.st_mode) < 0)
436 fatal_unexec ("setting protection on %s", name);
440 fatal_unexec (char *s, char *arg)
443 fputs ("unexec: unexpected end of file, ", stderr);
445 fprintf (stderr, "unexec: %s, ", strerror (errno));
446 fprintf (stderr, s, arg);
447 fputs (".\n", stderr);