code.delx.au - gnu-emacs/blob - src/unexmips.c

   1 /* Unexec for MIPS (including IRIS4D).
   2    Note that the GNU project considers support for MIPS operation
   3    a peripheral activity which should not be allowed to divert effort
   4    from development of the GNU system.  Changes in this code will be
   5    installed when users send them in, but aside from that
   6    we don't plan to think about it, or about whether other Emacs
   7    maintenance might break it.
   8
   9    Copyright (C) 1988, 1994 Free Software Foundation, Inc.
  10
  11 This file is part of GNU Emacs.
  12
  13 GNU Emacs is free software; you can redistribute it and/or modify
  14 it under the terms of the GNU General Public License as published by
  15 the Free Software Foundation; either version 2, or (at your option)
  16 any later version.
  17
  18 GNU Emacs is distributed in the hope that it will be useful,
  19 but WITHOUT ANY WARRANTY; without even the implied warranty of
  20 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21 GNU General Public License for more details.
  22
  23 You should have received a copy of the GNU General Public License
  24 along with GNU Emacs; see the file COPYING.  If not, write to
  25 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
  26
  27 \f
  28 #include <config.h>
  29 #include <sys/types.h>
  30 #include <sys/file.h>
  31 #include <sys/stat.h>
  32 #include <stdio.h>
  33 #include <varargs.h>
  34
  35 #ifdef MACH
  36
  37 #include <a.out.h>
  38
  39 /* I don't know why this isn't defined.  */
  40 #ifndef STYP_INIT
  41 #define STYP_INIT  0x80000000
  42 #endif
  43
  44 /* I don't know why this isn't defined.  */
  45 #ifndef _RDATA
  46 #define _RDATA  ".rdata"
  47 #define STYP_RDATA 0x00000100
  48 #endif
  49
  50 /* Small ("near") data section.  */
  51 #ifndef _SDATA
  52 #define _SDATA  ".sdata"
  53 #define STYP_SDATA 0x00000200
  54 #endif
  55
  56 /* Small ("near") bss section.  */
  57 #ifndef _SBSS
  58 #define _SBSS ".sbss"
  59 #define STYP_SBSS 0x00000400
  60 #endif
  61
  62 /* We don't seem to have a sym.h or syms.h anywhere, so we'll do it the
  63    hard way.  This stinks.  */
  64 typedef struct {
  65   short   magic;
  66   short   vstamp;
  67   long    ilineMax;
  68   struct { long foo, offset; } offsets[11];
  69 } HDRR, *pHDRR;
  70
  71 #else /* not MACH */
  72
  73 #include <filehdr.h>
  74 #include <aouthdr.h>
  75 #include <scnhdr.h>
  76 #include <sym.h>
  77
  78 #endif /* not MACH */
  79
  80 #if defined (IRIS_4D) || defined (sony)
  81 #include "getpagesize.h"
  82 #include <fcntl.h>
  83 #endif
  84
  85 static void fatal_unexec ();
  86 static void mark_x ();
  87
  88 #define READ(_fd, _buffer, _size, _error_message, _error_arg) \
  89         errno = EEOF; \
  90         if (read (_fd, _buffer, _size) != _size) \
  91           fatal_unexec (_error_message, _error_arg);
  92
  93 #define WRITE(_fd, _buffer, _size, _error_message, _error_arg) \
  94         if (write (_fd, _buffer, _size) != _size) \
  95           fatal_unexec (_error_message, _error_arg);
  96
  97 #define SEEK(_fd, _position, _error_message, _error_arg) \
  98         errno = EEOF; \
  99         if (lseek (_fd, _position, L_SET) != _position) \
 100           fatal_unexec (_error_message, _error_arg);
 101
 102 extern int errno;
 103 extern char *strerror ();
 104 #define EEOF -1
 105
 106 static struct scnhdr *text_section;
 107 static struct scnhdr *init_section;
 108 static struct scnhdr *finit_section;
 109 static struct scnhdr *rdata_section;
 110 static struct scnhdr *data_section;
 111 static struct scnhdr *lit8_section;
 112 static struct scnhdr *lit4_section;
 113 static struct scnhdr *sdata_section;
 114 static struct scnhdr *sbss_section;
 115 static struct scnhdr *bss_section;
 116
 117 struct headers {
 118     struct filehdr fhdr;
 119     struct aouthdr aout;
 120     struct scnhdr section[10];
 121 };
 122
 123 /* Define name of label for entry point for the dumped executable.  */
 124
 125 #ifndef DEFAULT_ENTRY_ADDRESS
 126 #define DEFAULT_ENTRY_ADDRESS __start
 127 #endif
 128 \f
 129 unexec (new_name, a_name, data_start, bss_start, entry_address)
 130      char *new_name, *a_name;
 131      unsigned data_start, bss_start, entry_address;
 132 {
 133   int new, old;
 134   int pagesize, brk;
 135   int newsyms, symrel;
 136   int nread;
 137   struct headers hdr;
 138   int i;
 139   int vaddr, scnptr;
 140 #define BUFSIZE 8192
 141   char buffer[BUFSIZE];
 142
 143   old = open (a_name, O_RDONLY, 0);
 144   if (old < 0) fatal_unexec ("opening %s", a_name);
 145
 146   new = creat (new_name, 0666);
 147   if (new < 0) fatal_unexec ("creating %s", new_name);
 148
 149   hdr = *((struct headers *)TEXT_START);
 150 #ifdef MIPS2
 151   if (hdr.fhdr.f_magic != MIPSELMAGIC
 152       && hdr.fhdr.f_magic != MIPSEBMAGIC
 153       && hdr.fhdr.f_magic != (MIPSELMAGIC | 1)
 154       && hdr.fhdr.f_magic != (MIPSEBMAGIC | 1))
 155     {
 156       fprintf (stderr,
 157                "unexec: input file magic number is %x, not %x, %x, %x or %x.\n",
 158                hdr.fhdr.f_magic,
 159                MIPSELMAGIC, MIPSEBMAGIC,
 160                MIPSELMAGIC | 1, MIPSEBMAGIC | 1);
 161       exit(1);
 162     }
 163 #else /* not MIPS2 */
 164   if (hdr.fhdr.f_magic != MIPSELMAGIC
 165       && hdr.fhdr.f_magic != MIPSEBMAGIC)
 166     {
 167       fprintf (stderr, "unexec: input file magic number is %x, not %x or %x.\n",
 168                hdr.fhdr.f_magic, MIPSELMAGIC, MIPSEBMAGIC);
 169       exit (1);
 170     }
 171 #endif /* not MIPS2 */
 172   if (hdr.fhdr.f_opthdr != sizeof (hdr.aout))
 173     {
 174       fprintf (stderr, "unexec: input a.out header is %d bytes, not %d.\n",
 175                hdr.fhdr.f_opthdr, sizeof (hdr.aout));
 176       exit (1);
 177     }
 178   if (hdr.aout.magic != ZMAGIC)
 179     {
 180       fprintf (stderr, "unexec: input file a.out magic number is %o, not %o.\n",
 181                hdr.aout.magic, ZMAGIC);
 182       exit (1);
 183     }
 184
 185 #define CHECK_SCNHDR(ptr, name, flags)                                  \
 186   ptr = NULL;                                                           \
 187   for (i = 0; i < hdr.fhdr.f_nscns && !ptr; i++)                        \
 188     if (strcmp (hdr.section[i].s_name, name) == 0)                      \
 189       {                                                                 \
 190         if (hdr.section[i].s_flags != flags)                            \
 191           fprintf (stderr, "unexec: %x flags (%x expected) in %s section.\n", \
 192                    hdr.section[i].s_flags, flags, name);                \
 193         ptr = hdr.section + i;                                          \
 194       }                                                                 \
 195
 196   CHECK_SCNHDR (text_section,  _TEXT,  STYP_TEXT);
 197   CHECK_SCNHDR (init_section,  _INIT,  STYP_INIT);
 198   CHECK_SCNHDR (rdata_section, _RDATA, STYP_RDATA);
 199   CHECK_SCNHDR (data_section,  _DATA,  STYP_DATA);
 200 #ifdef _LIT8
 201   CHECK_SCNHDR (lit8_section,  _LIT8,  STYP_LIT8);
 202   CHECK_SCNHDR (lit4_section,  _LIT4,  STYP_LIT4);
 203 #endif /* _LIT8 */
 204   CHECK_SCNHDR (sdata_section, _SDATA, STYP_SDATA);
 205   CHECK_SCNHDR (sbss_section,  _SBSS,  STYP_SBSS);
 206   CHECK_SCNHDR (bss_section,   _BSS,   STYP_BSS);
 207 #if 0 /* Apparently this error check goes off on irix 3.3,
 208          but it doesn't indicate a real problem.  */
 209   if (i != hdr.fhdr.f_nscns)
 210     fprintf (stderr, "unexec: %d sections found instead of %d.\n",
 211              i, hdr.fhdr.f_nscns);
 212 #endif
 213
 214   text_section->s_scnptr = 0;
 215
 216   pagesize = getpagesize ();
 217   /* Casting to int avoids compiler error on NEWS-OS 5.0.2.  */
 218   brk = (((int) (sbrk (0))) + pagesize - 1) & (-pagesize);
 219   hdr.aout.dsize = brk - DATA_START;
 220   hdr.aout.bsize = 0;
 221   if (entry_address == 0)
 222     {
 223       extern DEFAULT_ENTRY_ADDRESS ();
 224       hdr.aout.entry = (unsigned)DEFAULT_ENTRY_ADDRESS;
 225     }
 226   else
 227     hdr.aout.entry = entry_address;
 228
 229   hdr.aout.bss_start = hdr.aout.data_start + hdr.aout.dsize;
 230   rdata_section->s_size = data_start - DATA_START;
 231
 232   /* Adjust start and virtual addresses of rdata_section, too.  */
 233   rdata_section->s_vaddr = DATA_START;
 234   rdata_section->s_paddr = DATA_START;
 235   rdata_section->s_scnptr = text_section->s_scnptr + hdr.aout.tsize;
 236
 237   data_section->s_vaddr = data_start;
 238   data_section->s_paddr = data_start;
 239   data_section->s_size = brk - data_start;
 240   data_section->s_scnptr = rdata_section->s_scnptr + rdata_section->s_size;
 241   vaddr = data_section->s_vaddr + data_section->s_size;
 242   scnptr = data_section->s_scnptr + data_section->s_size;
 243   if (lit8_section != NULL)
 244     {
 245       lit8_section->s_vaddr = vaddr;
 246       lit8_section->s_paddr = vaddr;
 247       lit8_section->s_size = 0;
 248       lit8_section->s_scnptr = scnptr;
 249     }
 250   if (lit4_section != NULL)
 251     {
 252       lit4_section->s_vaddr = vaddr;
 253       lit4_section->s_paddr = vaddr;
 254       lit4_section->s_size = 0;
 255       lit4_section->s_scnptr = scnptr;
 256     }
 257   if (sdata_section != NULL)
 258     {
 259       sdata_section->s_vaddr = vaddr;
 260       sdata_section->s_paddr = vaddr;
 261       sdata_section->s_size = 0;
 262       sdata_section->s_scnptr = scnptr;
 263     }
 264   if (sbss_section != NULL)
 265     {
 266       sbss_section->s_vaddr = vaddr;
 267       sbss_section->s_paddr = vaddr;
 268       sbss_section->s_size = 0;
 269       sbss_section->s_scnptr = scnptr;
 270     }
 271   if (bss_section != NULL)
 272     {
 273       bss_section->s_vaddr = vaddr;
 274       bss_section->s_paddr = vaddr;
 275       bss_section->s_size = 0;
 276       bss_section->s_scnptr = scnptr;
 277     }
 278
 279   WRITE (new, (char *)TEXT_START, hdr.aout.tsize,
 280          "writing text section to %s", new_name);
 281   WRITE (new, (char *)DATA_START, hdr.aout.dsize,
 282          "writing data section to %s", new_name);
 283
 284   SEEK (old, hdr.fhdr.f_symptr, "seeking to start of symbols in %s", a_name);
 285   errno = EEOF;
 286   nread = read (old, buffer, BUFSIZE);
 287   if (nread < sizeof (HDRR)) fatal_unexec ("reading symbols from %s", a_name);
 288   newsyms = hdr.aout.tsize + hdr.aout.dsize;
 289   symrel = newsyms - hdr.fhdr.f_symptr;
 290   hdr.fhdr.f_symptr = newsyms;
 291 #define symhdr ((pHDRR)buffer)
 292 #ifdef MACH
 293   for (i = 0; i < 11; i++)
 294     symhdr->offsets[i].offset += symrel;
 295 #else
 296   symhdr->cbLineOffset += symrel;
 297   symhdr->cbDnOffset += symrel;
 298   symhdr->cbPdOffset += symrel;
 299   symhdr->cbSymOffset += symrel;
 300   symhdr->cbOptOffset += symrel;
 301   symhdr->cbAuxOffset += symrel;
 302   symhdr->cbSsOffset += symrel;
 303   symhdr->cbSsExtOffset += symrel;
 304   symhdr->cbFdOffset += symrel;
 305   symhdr->cbRfdOffset += symrel;
 306   symhdr->cbExtOffset += symrel;
 307 #endif
 308 #undef symhdr
 309   do
 310     {
 311       if (write (new, buffer, nread) != nread)
 312         fatal_unexec ("writing symbols to %s", new_name);
 313       nread = read (old, buffer, BUFSIZE);
 314       if (nread < 0) fatal_unexec ("reading symbols from %s", a_name);
 315 #undef BUFSIZE
 316     } while (nread != 0);
 317
 318   SEEK (new, 0, "seeking to start of header in %s", new_name);
 319   WRITE (new, &hdr, sizeof (hdr),
 320          "writing header of %s", new_name);
 321
 322   close (old);
 323   close (new);
 324   mark_x (new_name);
 325 }
 326 \f
 327 /*
 328  * mark_x
 329  *
 330  * After successfully building the new a.out, mark it executable
 331  */
 332
 333 static void
 334 mark_x (name)
 335      char *name;
 336 {
 337   struct stat sbuf;
 338   int um = umask (777);
 339   umask (um);
 340   if (stat (name, &sbuf) < 0)
 341     fatal_unexec ("getting protection on %s", name);
 342   sbuf.st_mode |= 0111 & ~um;
 343   if (chmod (name, sbuf.st_mode) < 0)
 344     fatal_unexec ("setting protection on %s", name);
 345 }
 346
 347 static void
 348 fatal_unexec (s, va_alist)
 349     va_dcl
 350 {
 351   va_list ap;
 352   if (errno == EEOF)
 353     fputs ("unexec: unexpected end of file, ", stderr);
 354   else
 355     fprintf (stderr, "unexec: %s, ", strerror (errno));
 356   va_start (ap);
 357   _doprnt (s, ap, stderr);
 358   fputs (".\n", stderr);
 359   exit (1);
 360 }