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, 2008  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   if (hdr.fhdr.f_magic != MIPSELMAGIC
 153       && hdr.fhdr.f_magic != MIPSEBMAGIC)
 154     {
 155       fprintf (stderr, "unexec: input file magic number is %x, not %x or %x.\n",
 156                hdr.fhdr.f_magic, MIPSELMAGIC, MIPSEBMAGIC);
 157       exit (1);
 158     }
 159   if (hdr.fhdr.f_opthdr != sizeof (hdr.aout))
 160     {
 161       fprintf (stderr, "unexec: input a.out header is %d bytes, not %d.\n",
 162                hdr.fhdr.f_opthdr, sizeof (hdr.aout));
 163       exit (1);
 164     }
 165   if (hdr.aout.magic != ZMAGIC)
 166     {
 167       fprintf (stderr, "unexec: input file a.out magic number is %o, not %o.\n",
 168                hdr.aout.magic, ZMAGIC);
 169       exit (1);
 170     }
 171
 172 #define CHECK_SCNHDR(ptr, name, flags)                                  \
 173   ptr = NULL;                                                           \
 174   for (i = 0; i < hdr.fhdr.f_nscns && !ptr; i++)                        \
 175     if (strcmp (hdr.section[i].s_name, name) == 0)                      \
 176       {                                                                 \
 177         if (hdr.section[i].s_flags != flags)                            \
 178           fprintf (stderr, "unexec: %x flags (%x expected) in %s section.\n", \
 179                    hdr.section[i].s_flags, flags, name);                \
 180         ptr = hdr.section + i;                                          \
 181       }                                                                 \
 182
 183   CHECK_SCNHDR (text_section,  _TEXT,  STYP_TEXT);
 184   CHECK_SCNHDR (init_section,  _INIT,  STYP_INIT);
 185   CHECK_SCNHDR (rdata_section, _RDATA, STYP_RDATA);
 186   CHECK_SCNHDR (data_section,  _DATA,  STYP_DATA);
 187 #ifdef _LIT8
 188   CHECK_SCNHDR (lit8_section,  _LIT8,  STYP_LIT8);
 189   CHECK_SCNHDR (lit4_section,  _LIT4,  STYP_LIT4);
 190 #endif /* _LIT8 */
 191   CHECK_SCNHDR (sdata_section, _SDATA, STYP_SDATA);
 192   CHECK_SCNHDR (sbss_section,  _SBSS,  STYP_SBSS);
 193   CHECK_SCNHDR (bss_section,   _BSS,   STYP_BSS);
 194 #if 0 /* Apparently this error check goes off on irix 3.3,
 195          but it doesn't indicate a real problem.  */
 196   if (i != hdr.fhdr.f_nscns)
 197     fprintf (stderr, "unexec: %d sections found instead of %d.\n",
 198              i, hdr.fhdr.f_nscns);
 199 #endif
 200
 201   text_section->s_scnptr = 0;
 202
 203   pagesize = getpagesize ();
 204   /* Casting to int avoids compiler error on NEWS-OS 5.0.2.  */
 205   brk = (((int) (sbrk (0))) + pagesize - 1) & (-pagesize);
 206   hdr.aout.dsize = brk - DATA_START;
 207   hdr.aout.bsize = 0;
 208   if (entry_address == 0)
 209     {
 210       extern DEFAULT_ENTRY_ADDRESS ();
 211       hdr.aout.entry = (unsigned)DEFAULT_ENTRY_ADDRESS;
 212     }
 213   else
 214     hdr.aout.entry = entry_address;
 215
 216   hdr.aout.bss_start = hdr.aout.data_start + hdr.aout.dsize;
 217   rdata_section->s_size = data_start - DATA_START;
 218
 219   /* Adjust start and virtual addresses of rdata_section, too.  */
 220   rdata_section->s_vaddr = DATA_START;
 221   rdata_section->s_paddr = DATA_START;
 222   rdata_section->s_scnptr = text_section->s_scnptr + hdr.aout.tsize;
 223
 224   data_section->s_vaddr = data_start;
 225   data_section->s_paddr = data_start;
 226   data_section->s_size = brk - data_start;
 227   data_section->s_scnptr = rdata_section->s_scnptr + rdata_section->s_size;
 228   vaddr = data_section->s_vaddr + data_section->s_size;
 229   scnptr = data_section->s_scnptr + data_section->s_size;
 230   if (lit8_section != NULL)
 231     {
 232       lit8_section->s_vaddr = vaddr;
 233       lit8_section->s_paddr = vaddr;
 234       lit8_section->s_size = 0;
 235       lit8_section->s_scnptr = scnptr;
 236     }
 237   if (lit4_section != NULL)
 238     {
 239       lit4_section->s_vaddr = vaddr;
 240       lit4_section->s_paddr = vaddr;
 241       lit4_section->s_size = 0;
 242       lit4_section->s_scnptr = scnptr;
 243     }
 244   if (sdata_section != NULL)
 245     {
 246       sdata_section->s_vaddr = vaddr;
 247       sdata_section->s_paddr = vaddr;
 248       sdata_section->s_size = 0;
 249       sdata_section->s_scnptr = scnptr;
 250     }
 251   if (sbss_section != NULL)
 252     {
 253       sbss_section->s_vaddr = vaddr;
 254       sbss_section->s_paddr = vaddr;
 255       sbss_section->s_size = 0;
 256       sbss_section->s_scnptr = scnptr;
 257     }
 258   if (bss_section != NULL)
 259     {
 260       bss_section->s_vaddr = vaddr;
 261       bss_section->s_paddr = vaddr;
 262       bss_section->s_size = 0;
 263       bss_section->s_scnptr = scnptr;
 264     }
 265
 266   WRITE (new, (char *)TEXT_START, hdr.aout.tsize,
 267          "writing text section to %s", new_name);
 268   WRITE (new, (char *)DATA_START, hdr.aout.dsize,
 269          "writing data section to %s", new_name);
 270
 271   SEEK (old, hdr.fhdr.f_symptr, "seeking to start of symbols in %s", a_name);
 272   errno = EEOF;
 273   nread = read (old, buffer, BUFSIZE);
 274   if (nread < sizeof (HDRR)) fatal_unexec ("reading symbols from %s", a_name);
 275   newsyms = hdr.aout.tsize + hdr.aout.dsize;
 276   symrel = newsyms - hdr.fhdr.f_symptr;
 277   hdr.fhdr.f_symptr = newsyms;
 278 #define symhdr ((pHDRR)buffer)
 279 #ifdef MACH
 280   for (i = 0; i < 11; i++)
 281     symhdr->offsets[i].offset += symrel;
 282 #else
 283   symhdr->cbLineOffset += symrel;
 284   symhdr->cbDnOffset += symrel;
 285   symhdr->cbPdOffset += symrel;
 286   symhdr->cbSymOffset += symrel;
 287   symhdr->cbOptOffset += symrel;
 288   symhdr->cbAuxOffset += symrel;
 289   symhdr->cbSsOffset += symrel;
 290   symhdr->cbSsExtOffset += symrel;
 291   symhdr->cbFdOffset += symrel;
 292   symhdr->cbRfdOffset += symrel;
 293   symhdr->cbExtOffset += symrel;
 294 #endif
 295 #undef symhdr
 296   do
 297     {
 298       if (write (new, buffer, nread) != nread)
 299         fatal_unexec ("writing symbols to %s", new_name);
 300       nread = read (old, buffer, BUFSIZE);
 301       if (nread < 0) fatal_unexec ("reading symbols from %s", a_name);
 302 #undef BUFSIZE
 303     } while (nread != 0);
 304
 305   SEEK (new, 0, "seeking to start of header in %s", new_name);
 306   WRITE (new, &hdr, sizeof (hdr),
 307          "writing header of %s", new_name);
 308
 309   close (old);
 310   close (new);
 311   mark_x (new_name);
 312 }
 313 \f
 314 /*
 315  * mark_x
 316  *
 317  * After successfully building the new a.out, mark it executable
 318  */
 319
 320 static void
 321 mark_x (name)
 322      char *name;
 323 {
 324   struct stat sbuf;
 325   int um = umask (777);
 326   umask (um);
 327   if (stat (name, &sbuf) < 0)
 328     fatal_unexec ("getting protection on %s", name);
 329   sbuf.st_mode |= 0111 & ~um;
 330   if (chmod (name, sbuf.st_mode) < 0)
 331     fatal_unexec ("setting protection on %s", name);
 332 }
 333
 334 static void
 335 fatal_unexec (s, va_alist)
 336     va_dcl
 337 {
 338   va_list ap;
 339   if (errno == EEOF)
 340     fputs ("unexec: unexpected end of file, ", stderr);
 341   else
 342     fprintf (stderr, "unexec: %s, ", strerror (errno));
 343   va_start (ap);
 344   _doprnt (s, ap, stderr);
 345   fputs (".\n", stderr);
 346   exit (1);
 347 }
 348
 349 /* arch-tag: ebdd2058-3bbc-4de4-b5c7-5760379ab153
 350    (do not change this comment) */