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, 2002, 2003, 2004,
  10                  2005 Free Software Foundation, Inc.
  11
  12 This file is part of GNU Emacs.
  13
  14 GNU Emacs is free software; you can redistribute it and/or modify
  15 it under the terms of the GNU General Public License as published by
  16 the Free Software Foundation; either version 2, or (at your option)
  17 any later version.
  18
  19 GNU Emacs is distributed in the hope that it will be useful,
  20 but WITHOUT ANY WARRANTY; without even the implied warranty of
  21 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22 GNU General Public License for more details.
  23
  24 You should have received a copy of the GNU General Public License
  25 along with GNU Emacs; see the file COPYING.  If not, write to
  26 the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  27 Boston, MA 02110-1301, USA.  */
  28
  29 \f
  30 #include <config.h>
  31 #include <sys/types.h>
  32 #include <sys/file.h>
  33 #include <sys/stat.h>
  34 #include <stdio.h>
  35 #include <varargs.h>
  36
  37 #ifdef MACH
  38
  39 #include <a.out.h>
  40
  41 /* I don't know why this isn't defined.  */
  42 #ifndef STYP_INIT
  43 #define STYP_INIT  0x80000000
  44 #endif
  45
  46 /* I don't know why this isn't defined.  */
  47 #ifndef _RDATA
  48 #define _RDATA  ".rdata"
  49 #define STYP_RDATA 0x00000100
  50 #endif
  51
  52 /* Small ("near") data section.  */
  53 #ifndef _SDATA
  54 #define _SDATA  ".sdata"
  55 #define STYP_SDATA 0x00000200
  56 #endif
  57
  58 /* Small ("near") bss section.  */
  59 #ifndef _SBSS
  60 #define _SBSS ".sbss"
  61 #define STYP_SBSS 0x00000400
  62 #endif
  63
  64 /* We don't seem to have a sym.h or syms.h anywhere, so we'll do it the
  65    hard way.  This stinks.  */
  66 typedef struct {
  67   short   magic;
  68   short   vstamp;
  69   long    ilineMax;
  70   struct { long foo, offset; } offsets[11];
  71 } HDRR, *pHDRR;
  72
  73 #else /* not MACH */
  74
  75 #include <filehdr.h>
  76 #include <aouthdr.h>
  77 #include <scnhdr.h>
  78 #include <sym.h>
  79
  80 #endif /* not MACH */
  81
  82 #if defined (IRIS_4D) || defined (sony)
  83 #include "getpagesize.h"
  84 #include <fcntl.h>
  85 #endif
  86
  87 static void fatal_unexec ();
  88 static void mark_x ();
  89
  90 #define READ(_fd, _buffer, _size, _error_message, _error_arg) \
  91         errno = EEOF; \
  92         if (read (_fd, _buffer, _size) != _size) \
  93           fatal_unexec (_error_message, _error_arg);
  94
  95 #define WRITE(_fd, _buffer, _size, _error_message, _error_arg) \
  96         if (write (_fd, _buffer, _size) != _size) \
  97           fatal_unexec (_error_message, _error_arg);
  98
  99 #define SEEK(_fd, _position, _error_message, _error_arg) \
 100         errno = EEOF; \
 101         if (lseek (_fd, _position, L_SET) != _position) \
 102           fatal_unexec (_error_message, _error_arg);
 103
 104 extern int errno;
 105 extern char *strerror ();
 106 #define EEOF -1
 107
 108 static struct scnhdr *text_section;
 109 static struct scnhdr *init_section;
 110 static struct scnhdr *finit_section;
 111 static struct scnhdr *rdata_section;
 112 static struct scnhdr *data_section;
 113 static struct scnhdr *lit8_section;
 114 static struct scnhdr *lit4_section;
 115 static struct scnhdr *sdata_section;
 116 static struct scnhdr *sbss_section;
 117 static struct scnhdr *bss_section;
 118
 119 struct headers {
 120     struct filehdr fhdr;
 121     struct aouthdr aout;
 122     struct scnhdr section[10];
 123 };
 124
 125 /* Define name of label for entry point for the dumped executable.  */
 126
 127 #ifndef DEFAULT_ENTRY_ADDRESS
 128 #define DEFAULT_ENTRY_ADDRESS __start
 129 #endif
 130 \f
 131 unexec (new_name, a_name, data_start, bss_start, entry_address)
 132      char *new_name, *a_name;
 133      unsigned data_start, bss_start, entry_address;
 134 {
 135   int new, old;
 136   int pagesize, brk;
 137   int newsyms, symrel;
 138   int nread;
 139   struct headers hdr;
 140   int i;
 141   int vaddr, scnptr;
 142 #define BUFSIZE 8192
 143   char buffer[BUFSIZE];
 144
 145   old = open (a_name, O_RDONLY, 0);
 146   if (old < 0) fatal_unexec ("opening %s", a_name);
 147
 148   new = creat (new_name, 0666);
 149   if (new < 0) fatal_unexec ("creating %s", new_name);
 150
 151   hdr = *((struct headers *)TEXT_START);
 152 #ifdef MIPS2
 153   if (hdr.fhdr.f_magic != MIPSELMAGIC
 154       && hdr.fhdr.f_magic != MIPSEBMAGIC
 155       && hdr.fhdr.f_magic != (MIPSELMAGIC | 1)
 156       && hdr.fhdr.f_magic != (MIPSEBMAGIC | 1))
 157     {
 158       fprintf (stderr,
 159                "unexec: input file magic number is %x, not %x, %x, %x or %x.\n",
 160                hdr.fhdr.f_magic,
 161                MIPSELMAGIC, MIPSEBMAGIC,
 162                MIPSELMAGIC | 1, MIPSEBMAGIC | 1);
 163       exit(1);
 164     }
 165 #else /* not MIPS2 */
 166   if (hdr.fhdr.f_magic != MIPSELMAGIC
 167       && hdr.fhdr.f_magic != MIPSEBMAGIC)
 168     {
 169       fprintf (stderr, "unexec: input file magic number is %x, not %x or %x.\n",
 170                hdr.fhdr.f_magic, MIPSELMAGIC, MIPSEBMAGIC);
 171       exit (1);
 172     }
 173 #endif /* not MIPS2 */
 174   if (hdr.fhdr.f_opthdr != sizeof (hdr.aout))
 175     {
 176       fprintf (stderr, "unexec: input a.out header is %d bytes, not %d.\n",
 177                hdr.fhdr.f_opthdr, sizeof (hdr.aout));
 178       exit (1);
 179     }
 180   if (hdr.aout.magic != ZMAGIC)
 181     {
 182       fprintf (stderr, "unexec: input file a.out magic number is %o, not %o.\n",
 183                hdr.aout.magic, ZMAGIC);
 184       exit (1);
 185     }
 186
 187 #define CHECK_SCNHDR(ptr, name, flags)                                  \
 188   ptr = NULL;                                                           \
 189   for (i = 0; i < hdr.fhdr.f_nscns && !ptr; i++)                        \
 190     if (strcmp (hdr.section[i].s_name, name) == 0)                      \
 191       {                                                                 \
 192         if (hdr.section[i].s_flags != flags)                            \
 193           fprintf (stderr, "unexec: %x flags (%x expected) in %s section.\n", \
 194                    hdr.section[i].s_flags, flags, name);                \
 195         ptr = hdr.section + i;                                          \
 196       }                                                                 \
 197
 198   CHECK_SCNHDR (text_section,  _TEXT,  STYP_TEXT);
 199   CHECK_SCNHDR (init_section,  _INIT,  STYP_INIT);
 200   CHECK_SCNHDR (rdata_section, _RDATA, STYP_RDATA);
 201   CHECK_SCNHDR (data_section,  _DATA,  STYP_DATA);
 202 #ifdef _LIT8
 203   CHECK_SCNHDR (lit8_section,  _LIT8,  STYP_LIT8);
 204   CHECK_SCNHDR (lit4_section,  _LIT4,  STYP_LIT4);
 205 #endif /* _LIT8 */
 206   CHECK_SCNHDR (sdata_section, _SDATA, STYP_SDATA);
 207   CHECK_SCNHDR (sbss_section,  _SBSS,  STYP_SBSS);
 208   CHECK_SCNHDR (bss_section,   _BSS,   STYP_BSS);
 209 #if 0 /* Apparently this error check goes off on irix 3.3,
 210          but it doesn't indicate a real problem.  */
 211   if (i != hdr.fhdr.f_nscns)
 212     fprintf (stderr, "unexec: %d sections found instead of %d.\n",
 213              i, hdr.fhdr.f_nscns);
 214 #endif
 215
 216   text_section->s_scnptr = 0;
 217
 218   pagesize = getpagesize ();
 219   /* Casting to int avoids compiler error on NEWS-OS 5.0.2.  */
 220   brk = (((int) (sbrk (0))) + pagesize - 1) & (-pagesize);
 221   hdr.aout.dsize = brk - DATA_START;
 222   hdr.aout.bsize = 0;
 223   if (entry_address == 0)
 224     {
 225       extern DEFAULT_ENTRY_ADDRESS ();
 226       hdr.aout.entry = (unsigned)DEFAULT_ENTRY_ADDRESS;
 227     }
 228   else
 229     hdr.aout.entry = entry_address;
 230
 231   hdr.aout.bss_start = hdr.aout.data_start + hdr.aout.dsize;
 232   rdata_section->s_size = data_start - DATA_START;
 233
 234   /* Adjust start and virtual addresses of rdata_section, too.  */
 235   rdata_section->s_vaddr = DATA_START;
 236   rdata_section->s_paddr = DATA_START;
 237   rdata_section->s_scnptr = text_section->s_scnptr + hdr.aout.tsize;
 238
 239   data_section->s_vaddr = data_start;
 240   data_section->s_paddr = data_start;
 241   data_section->s_size = brk - data_start;
 242   data_section->s_scnptr = rdata_section->s_scnptr + rdata_section->s_size;
 243   vaddr = data_section->s_vaddr + data_section->s_size;
 244   scnptr = data_section->s_scnptr + data_section->s_size;
 245   if (lit8_section != NULL)
 246     {
 247       lit8_section->s_vaddr = vaddr;
 248       lit8_section->s_paddr = vaddr;
 249       lit8_section->s_size = 0;
 250       lit8_section->s_scnptr = scnptr;
 251     }
 252   if (lit4_section != NULL)
 253     {
 254       lit4_section->s_vaddr = vaddr;
 255       lit4_section->s_paddr = vaddr;
 256       lit4_section->s_size = 0;
 257       lit4_section->s_scnptr = scnptr;
 258     }
 259   if (sdata_section != NULL)
 260     {
 261       sdata_section->s_vaddr = vaddr;
 262       sdata_section->s_paddr = vaddr;
 263       sdata_section->s_size = 0;
 264       sdata_section->s_scnptr = scnptr;
 265     }
 266   if (sbss_section != NULL)
 267     {
 268       sbss_section->s_vaddr = vaddr;
 269       sbss_section->s_paddr = vaddr;
 270       sbss_section->s_size = 0;
 271       sbss_section->s_scnptr = scnptr;
 272     }
 273   if (bss_section != NULL)
 274     {
 275       bss_section->s_vaddr = vaddr;
 276       bss_section->s_paddr = vaddr;
 277       bss_section->s_size = 0;
 278       bss_section->s_scnptr = scnptr;
 279     }
 280
 281   WRITE (new, (char *)TEXT_START, hdr.aout.tsize,
 282          "writing text section to %s", new_name);
 283   WRITE (new, (char *)DATA_START, hdr.aout.dsize,
 284          "writing data section to %s", new_name);
 285
 286   SEEK (old, hdr.fhdr.f_symptr, "seeking to start of symbols in %s", a_name);
 287   errno = EEOF;
 288   nread = read (old, buffer, BUFSIZE);
 289   if (nread < sizeof (HDRR)) fatal_unexec ("reading symbols from %s", a_name);
 290   newsyms = hdr.aout.tsize + hdr.aout.dsize;
 291   symrel = newsyms - hdr.fhdr.f_symptr;
 292   hdr.fhdr.f_symptr = newsyms;
 293 #define symhdr ((pHDRR)buffer)
 294 #ifdef MACH
 295   for (i = 0; i < 11; i++)
 296     symhdr->offsets[i].offset += symrel;
 297 #else
 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;
 309 #endif
 310 #undef symhdr
 311   do
 312     {
 313       if (write (new, buffer, nread) != nread)
 314         fatal_unexec ("writing symbols to %s", new_name);
 315       nread = read (old, buffer, BUFSIZE);
 316       if (nread < 0) fatal_unexec ("reading symbols from %s", a_name);
 317 #undef BUFSIZE
 318     } while (nread != 0);
 319
 320   SEEK (new, 0, "seeking to start of header in %s", new_name);
 321   WRITE (new, &hdr, sizeof (hdr),
 322          "writing header of %s", new_name);
 323
 324   close (old);
 325   close (new);
 326   mark_x (new_name);
 327 }
 328 \f
 329 /*
 330  * mark_x
 331  *
 332  * After successfully building the new a.out, mark it executable
 333  */
 334
 335 static void
 336 mark_x (name)
 337      char *name;
 338 {
 339   struct stat sbuf;
 340   int um = umask (777);
 341   umask (um);
 342   if (stat (name, &sbuf) < 0)
 343     fatal_unexec ("getting protection on %s", name);
 344   sbuf.st_mode |= 0111 & ~um;
 345   if (chmod (name, sbuf.st_mode) < 0)
 346     fatal_unexec ("setting protection on %s", name);
 347 }
 348
 349 static void
 350 fatal_unexec (s, va_alist)
 351     va_dcl
 352 {
 353   va_list ap;
 354   if (errno == EEOF)
 355     fputs ("unexec: unexpected end of file, ", stderr);
 356   else
 357     fprintf (stderr, "unexec: %s, ", strerror (errno));
 358   va_start (ap);
 359   _doprnt (s, ap, stderr);
 360   fputs (".\n", stderr);
 361   exit (1);
 362 }
 363
 364 /* arch-tag: ebdd2058-3bbc-4de4-b5c7-5760379ab153
 365    (do not change this comment) */