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, Inc., 51 Franklin Street, Fifth Floor,
  26 Boston, MA 02110-1301, USA.  */
  27
  28 \f
  29 #include <config.h>
  30 #include <sys/types.h>
  31 #include <sys/file.h>
  32 #include <sys/stat.h>
  33 #include <stdio.h>
  34 #include <varargs.h>
  35
  36 #ifdef MACH
  37
  38 #include <a.out.h>
  39
  40 /* I don't know why this isn't defined.  */
  41 #ifndef STYP_INIT
  42 #define STYP_INIT  0x80000000
  43 #endif
  44
  45 /* I don't know why this isn't defined.  */
  46 #ifndef _RDATA
  47 #define _RDATA  ".rdata"
  48 #define STYP_RDATA 0x00000100
  49 #endif
  50
  51 /* Small ("near") data section.  */
  52 #ifndef _SDATA
  53 #define _SDATA  ".sdata"
  54 #define STYP_SDATA 0x00000200
  55 #endif
  56
  57 /* Small ("near") bss section.  */
  58 #ifndef _SBSS
  59 #define _SBSS ".sbss"
  60 #define STYP_SBSS 0x00000400
  61 #endif
  62
  63 /* We don't seem to have a sym.h or syms.h anywhere, so we'll do it the
  64    hard way.  This stinks.  */
  65 typedef struct {
  66   short   magic;
  67   short   vstamp;
  68   long    ilineMax;
  69   struct { long foo, offset; } offsets[11];
  70 } HDRR, *pHDRR;
  71
  72 #else /* not MACH */
  73
  74 #include <filehdr.h>
  75 #include <aouthdr.h>
  76 #include <scnhdr.h>
  77 #include <sym.h>
  78
  79 #endif /* not MACH */
  80
  81 #if defined (IRIS_4D) || defined (sony)
  82 #include "getpagesize.h"
  83 #include <fcntl.h>
  84 #endif
  85
  86 static void fatal_unexec ();
  87 static void mark_x ();
  88
  89 #define READ(_fd, _buffer, _size, _error_message, _error_arg) \
  90         errno = EEOF; \
  91         if (read (_fd, _buffer, _size) != _size) \
  92           fatal_unexec (_error_message, _error_arg);
  93
  94 #define WRITE(_fd, _buffer, _size, _error_message, _error_arg) \
  95         if (write (_fd, _buffer, _size) != _size) \
  96           fatal_unexec (_error_message, _error_arg);
  97
  98 #define SEEK(_fd, _position, _error_message, _error_arg) \
  99         errno = EEOF; \
 100         if (lseek (_fd, _position, L_SET) != _position) \
 101           fatal_unexec (_error_message, _error_arg);
 102
 103 extern int errno;
 104 extern char *strerror ();
 105 #define EEOF -1
 106
 107 static struct scnhdr *text_section;
 108 static struct scnhdr *init_section;
 109 static struct scnhdr *finit_section;
 110 static struct scnhdr *rdata_section;
 111 static struct scnhdr *data_section;
 112 static struct scnhdr *lit8_section;
 113 static struct scnhdr *lit4_section;
 114 static struct scnhdr *sdata_section;
 115 static struct scnhdr *sbss_section;
 116 static struct scnhdr *bss_section;
 117
 118 struct headers {
 119     struct filehdr fhdr;
 120     struct aouthdr aout;
 121     struct scnhdr section[10];
 122 };
 123
 124 /* Define name of label for entry point for the dumped executable.  */
 125
 126 #ifndef DEFAULT_ENTRY_ADDRESS
 127 #define DEFAULT_ENTRY_ADDRESS __start
 128 #endif
 129 \f
 130 unexec (new_name, a_name, data_start, bss_start, entry_address)
 131      char *new_name, *a_name;
 132      unsigned data_start, bss_start, entry_address;
 133 {
 134   int new, old;
 135   int pagesize, brk;
 136   int newsyms, symrel;
 137   int nread;
 138   struct headers hdr;
 139   int i;
 140   int vaddr, scnptr;
 141 #define BUFSIZE 8192
 142   char buffer[BUFSIZE];
 143
 144   old = open (a_name, O_RDONLY, 0);
 145   if (old < 0) fatal_unexec ("opening %s", a_name);
 146
 147   new = creat (new_name, 0666);
 148   if (new < 0) fatal_unexec ("creating %s", new_name);
 149
 150   hdr = *((struct headers *)TEXT_START);
 151 #ifdef MIPS2
 152   if (hdr.fhdr.f_magic != MIPSELMAGIC
 153       && hdr.fhdr.f_magic != MIPSEBMAGIC
 154       && hdr.fhdr.f_magic != (MIPSELMAGIC | 1)
 155       && hdr.fhdr.f_magic != (MIPSEBMAGIC | 1))
 156     {
 157       fprintf (stderr,
 158                "unexec: input file magic number is %x, not %x, %x, %x or %x.\n",
 159                hdr.fhdr.f_magic,
 160                MIPSELMAGIC, MIPSEBMAGIC,
 161                MIPSELMAGIC | 1, MIPSEBMAGIC | 1);
 162       exit(1);
 163     }
 164 #else /* not MIPS2 */
 165   if (hdr.fhdr.f_magic != MIPSELMAGIC
 166       && hdr.fhdr.f_magic != MIPSEBMAGIC)
 167     {
 168       fprintf (stderr, "unexec: input file magic number is %x, not %x or %x.\n",
 169                hdr.fhdr.f_magic, MIPSELMAGIC, MIPSEBMAGIC);
 170       exit (1);
 171     }
 172 #endif /* not MIPS2 */
 173   if (hdr.fhdr.f_opthdr != sizeof (hdr.aout))
 174     {
 175       fprintf (stderr, "unexec: input a.out header is %d bytes, not %d.\n",
 176                hdr.fhdr.f_opthdr, sizeof (hdr.aout));
 177       exit (1);
 178     }
 179   if (hdr.aout.magic != ZMAGIC)
 180     {
 181       fprintf (stderr, "unexec: input file a.out magic number is %o, not %o.\n",
 182                hdr.aout.magic, ZMAGIC);
 183       exit (1);
 184     }
 185
 186 #define CHECK_SCNHDR(ptr, name, flags)                                  \
 187   ptr = NULL;                                                           \
 188   for (i = 0; i < hdr.fhdr.f_nscns && !ptr; i++)                        \
 189     if (strcmp (hdr.section[i].s_name, name) == 0)                      \
 190       {                                                                 \
 191         if (hdr.section[i].s_flags != flags)                            \
 192           fprintf (stderr, "unexec: %x flags (%x expected) in %s section.\n", \
 193                    hdr.section[i].s_flags, flags, name);                \
 194         ptr = hdr.section + i;                                          \
 195       }                                                                 \
 196
 197   CHECK_SCNHDR (text_section,  _TEXT,  STYP_TEXT);
 198   CHECK_SCNHDR (init_section,  _INIT,  STYP_INIT);
 199   CHECK_SCNHDR (rdata_section, _RDATA, STYP_RDATA);
 200   CHECK_SCNHDR (data_section,  _DATA,  STYP_DATA);
 201 #ifdef _LIT8
 202   CHECK_SCNHDR (lit8_section,  _LIT8,  STYP_LIT8);
 203   CHECK_SCNHDR (lit4_section,  _LIT4,  STYP_LIT4);
 204 #endif /* _LIT8 */
 205   CHECK_SCNHDR (sdata_section, _SDATA, STYP_SDATA);
 206   CHECK_SCNHDR (sbss_section,  _SBSS,  STYP_SBSS);
 207   CHECK_SCNHDR (bss_section,   _BSS,   STYP_BSS);
 208 #if 0 /* Apparently this error check goes off on irix 3.3,
 209          but it doesn't indicate a real problem.  */
 210   if (i != hdr.fhdr.f_nscns)
 211     fprintf (stderr, "unexec: %d sections found instead of %d.\n",
 212              i, hdr.fhdr.f_nscns);
 213 #endif
 214
 215   text_section->s_scnptr = 0;
 216
 217   pagesize = getpagesize ();
 218   /* Casting to int avoids compiler error on NEWS-OS 5.0.2.  */
 219   brk = (((int) (sbrk (0))) + pagesize - 1) & (-pagesize);
 220   hdr.aout.dsize = brk - DATA_START;
 221   hdr.aout.bsize = 0;
 222   if (entry_address == 0)
 223     {
 224       extern DEFAULT_ENTRY_ADDRESS ();
 225       hdr.aout.entry = (unsigned)DEFAULT_ENTRY_ADDRESS;
 226     }
 227   else
 228     hdr.aout.entry = entry_address;
 229
 230   hdr.aout.bss_start = hdr.aout.data_start + hdr.aout.dsize;
 231   rdata_section->s_size = data_start - DATA_START;
 232
 233   /* Adjust start and virtual addresses of rdata_section, too.  */
 234   rdata_section->s_vaddr = DATA_START;
 235   rdata_section->s_paddr = DATA_START;
 236   rdata_section->s_scnptr = text_section->s_scnptr + hdr.aout.tsize;
 237
 238   data_section->s_vaddr = data_start;
 239   data_section->s_paddr = data_start;
 240   data_section->s_size = brk - data_start;
 241   data_section->s_scnptr = rdata_section->s_scnptr + rdata_section->s_size;
 242   vaddr = data_section->s_vaddr + data_section->s_size;
 243   scnptr = data_section->s_scnptr + data_section->s_size;
 244   if (lit8_section != NULL)
 245     {
 246       lit8_section->s_vaddr = vaddr;
 247       lit8_section->s_paddr = vaddr;
 248       lit8_section->s_size = 0;
 249       lit8_section->s_scnptr = scnptr;
 250     }
 251   if (lit4_section != NULL)
 252     {
 253       lit4_section->s_vaddr = vaddr;
 254       lit4_section->s_paddr = vaddr;
 255       lit4_section->s_size = 0;
 256       lit4_section->s_scnptr = scnptr;
 257     }
 258   if (sdata_section != NULL)
 259     {
 260       sdata_section->s_vaddr = vaddr;
 261       sdata_section->s_paddr = vaddr;
 262       sdata_section->s_size = 0;
 263       sdata_section->s_scnptr = scnptr;
 264     }
 265   if (sbss_section != NULL)
 266     {
 267       sbss_section->s_vaddr = vaddr;
 268       sbss_section->s_paddr = vaddr;
 269       sbss_section->s_size = 0;
 270       sbss_section->s_scnptr = scnptr;
 271     }
 272   if (bss_section != NULL)
 273     {
 274       bss_section->s_vaddr = vaddr;
 275       bss_section->s_paddr = vaddr;
 276       bss_section->s_size = 0;
 277       bss_section->s_scnptr = scnptr;
 278     }
 279
 280   WRITE (new, (char *)TEXT_START, hdr.aout.tsize,
 281          "writing text section to %s", new_name);
 282   WRITE (new, (char *)DATA_START, hdr.aout.dsize,
 283          "writing data section to %s", new_name);
 284
 285   SEEK (old, hdr.fhdr.f_symptr, "seeking to start of symbols in %s", a_name);
 286   errno = EEOF;
 287   nread = read (old, buffer, BUFSIZE);
 288   if (nread < sizeof (HDRR)) fatal_unexec ("reading symbols from %s", a_name);
 289   newsyms = hdr.aout.tsize + hdr.aout.dsize;
 290   symrel = newsyms - hdr.fhdr.f_symptr;
 291   hdr.fhdr.f_symptr = newsyms;
 292 #define symhdr ((pHDRR)buffer)
 293 #ifdef MACH
 294   for (i = 0; i < 11; i++)
 295     symhdr->offsets[i].offset += symrel;
 296 #else
 297   symhdr->cbLineOffset += symrel;
 298   symhdr->cbDnOffset += symrel;
 299   symhdr->cbPdOffset += symrel;
 300   symhdr->cbSymOffset += symrel;
 301   symhdr->cbOptOffset += symrel;
 302   symhdr->cbAuxOffset += symrel;
 303   symhdr->cbSsOffset += symrel;
 304   symhdr->cbSsExtOffset += symrel;
 305   symhdr->cbFdOffset += symrel;
 306   symhdr->cbRfdOffset += symrel;
 307   symhdr->cbExtOffset += symrel;
 308 #endif
 309 #undef symhdr
 310   do
 311     {
 312       if (write (new, buffer, nread) != nread)
 313         fatal_unexec ("writing symbols to %s", new_name);
 314       nread = read (old, buffer, BUFSIZE);
 315       if (nread < 0) fatal_unexec ("reading symbols from %s", a_name);
 316 #undef BUFSIZE
 317     } while (nread != 0);
 318
 319   SEEK (new, 0, "seeking to start of header in %s", new_name);
 320   WRITE (new, &hdr, sizeof (hdr),
 321          "writing header of %s", new_name);
 322
 323   close (old);
 324   close (new);
 325   mark_x (new_name);
 326 }
 327 \f
 328 /*
 329  * mark_x
 330  *
 331  * After successfully building the new a.out, mark it executable
 332  */
 333
 334 static void
 335 mark_x (name)
 336      char *name;
 337 {
 338   struct stat sbuf;
 339   int um = umask (777);
 340   umask (um);
 341   if (stat (name, &sbuf) < 0)
 342     fatal_unexec ("getting protection on %s", name);
 343   sbuf.st_mode |= 0111 & ~um;
 344   if (chmod (name, sbuf.st_mode) < 0)
 345     fatal_unexec ("setting protection on %s", name);
 346 }
 347
 348 static void
 349 fatal_unexec (s, va_alist)
 350     va_dcl
 351 {
 352   va_list ap;
 353   if (errno == EEOF)
 354     fputs ("unexec: unexpected end of file, ", stderr);
 355   else
 356     fprintf (stderr, "unexec: %s, ", strerror (errno));
 357   va_start (ap);
 358   _doprnt (s, ap, stderr);
 359   fputs (".\n", stderr);
 360   exit (1);
 361 }
 362
 363 /* arch-tag: ebdd2058-3bbc-4de4-b5c7-5760379ab153
 364    (do not change this comment) */