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, 2001, 2002, 2003, 2004,
  10                  2005, 2006, 2007  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 3, 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) */