bfd/cisco-core.c

   1 /* BFD back-end for CISCO crash dumps.
   2
   3 Copyright 1994 Free Software Foundation, Inc.
   4
   5 This file is part of BFD, the Binary File Descriptor library.
   6
   7 This program is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2 of the License, or
  10 (at your option) any later version.
  11
  12 This program is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with this program; if not, write to the Free Software
  19 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  20
  21 #include "bfd.h"
  22 #include "sysdep.h"
  23 #include "libbfd.h"
  24 /* core_file_failing_signal returns a host signal (this probably should
  25    be fixed).  */
  26 #include <signal.h>
  27
  28 /* for MSVC builds */
  29 #ifndef SIGTRAP
  30 # define SIGTRAP 5
  31 #endif
  32 #ifndef SIGEMT
  33 # define SIGEMT 6
  34 #endif
  35 #ifndef SIGBUS
  36 # define SIGBUS 10
  37 #endif
  38 \f
  39 int crash_info_locs[] = {
  40   0x0250,       /* mips, ppc, x86, i960 */
  41   0x0400,       /* m68k, mips, x86, i960 */
  42   0x0FFC,       /* m68k, mips, ppc, x86, i960 */
  43   0x3000,       /* ppc */
  44   0x4FFC,       /* m68k */
  45   -1
  46 };
  47
  48 #define CRASH_MAGIC     0xdead1234
  49 #define MASK_ADDR(x)    ((x) & 0x0fffffff)      /* Mask crash info address */
  50
  51 typedef enum {
  52     CRASH_REASON_NOTCRASHED = 0,
  53     CRASH_REASON_EXCEPTION = 1,
  54     CRASH_REASON_CORRUPT = 2,
  55 } crashreason;
  56
  57 typedef struct {
  58   char magic[4];                /* Magic number */
  59   char version[4];              /* Version number */
  60   char reason[4];               /* Crash reason */
  61   char cpu_vector[4];           /* CPU vector for exceptions */
  62   char registers[4];            /* Pointer to saved registers */
  63   char rambase[4];              /* Base of RAM (not in V1 crash info) */
  64   char textbase[4];             /* Base of .text section (not in V3 crash info) */
  65   char database[4];             /* Base of .data section (not in V3 crash info) */
  66   char bssbase[4];              /* Base of .bss section (not in V3 crash info) */
  67 } crashinfo_external;
  68 \f
  69 struct cisco_core_struct
  70 {
  71   int sig;
  72 };
  73 \f
  74 /* Examine the file for a crash info struct at the offset given by
  75    CRASH_INFO_LOC. */
  76
  77 static const bfd_target *
  78 cisco_core_file_validate (abfd, crash_info_loc)
  79      bfd *abfd;
  80      int crash_info_loc;
  81 {
  82   char buf[4];
  83   unsigned int crashinfo_offset;
  84   crashinfo_external crashinfo;
  85   int nread;
  86   unsigned int magic;
  87   unsigned int version;
  88   unsigned int rambase;
  89   sec_ptr asect;
  90   struct stat statbuf;
  91
  92   if (bfd_seek (abfd, crash_info_loc, SEEK_SET) != 0)
  93     return NULL;
  94
  95   nread = bfd_read (buf, 1, 4, abfd);
  96   if (nread != 4)
  97     {
  98       if (bfd_get_error () != bfd_error_system_call)
  99         bfd_set_error (bfd_error_wrong_format);
 100       return NULL;
 101     }
 102   crashinfo_offset = MASK_ADDR (bfd_get_32 (abfd, buf));
 103
 104   if (bfd_seek (abfd, crashinfo_offset, SEEK_SET) != 0)
 105     {
 106       /* Most likely we failed because of a bogus (huge) offset */
 107       bfd_set_error (bfd_error_wrong_format);
 108       return NULL;
 109     }
 110
 111   nread = bfd_read (&crashinfo, 1, sizeof (crashinfo), abfd);
 112   if (nread != sizeof (crashinfo))
 113     {
 114       if (bfd_get_error () != bfd_error_system_call)
 115         bfd_set_error (bfd_error_wrong_format);
 116       return NULL;
 117     }
 118
 119   if (bfd_stat (abfd, &statbuf) < 0)
 120     {
 121       bfd_set_error (bfd_error_system_call);
 122       return NULL;
 123     }
 124
 125   magic = bfd_get_32 (abfd, crashinfo.magic);
 126   if (magic != CRASH_MAGIC)
 127     {
 128       bfd_set_error (bfd_error_wrong_format);
 129       return NULL;
 130     }
 131
 132   version = bfd_get_32 (abfd, crashinfo.version);
 133   if (version == 0)
 134     {
 135       bfd_set_error (bfd_error_wrong_format);
 136       return NULL;
 137     }
 138   else if (version == 1)
 139     {
 140       /* V1 core dumps don't specify the dump base, assume 0 */
 141       rambase = 0;
 142     }
 143   else
 144     {
 145       rambase = bfd_get_32 (abfd, crashinfo.rambase);
 146     }
 147
 148   /* OK, we believe you.  You're a core file.  */
 149
 150   abfd->tdata.cisco_core_data =
 151     ((struct cisco_core_struct *)
 152      bfd_zmalloc (sizeof (struct cisco_core_struct)));
 153   if (abfd->tdata.cisco_core_data == NULL)
 154     return NULL;
 155
 156   switch ((crashreason) bfd_get_32 (abfd, crashinfo.reason))
 157     {
 158     case CRASH_REASON_NOTCRASHED:
 159       /* Crash file probably came from write core.  */
 160       abfd->tdata.cisco_core_data->sig = 0;
 161       break;
 162     case CRASH_REASON_CORRUPT:
 163       /* The crash context area was corrupt -- proceed with caution.
 164          We have no way of passing this information back to the caller.  */
 165       abfd->tdata.cisco_core_data->sig = 0;
 166       break;
 167     case CRASH_REASON_EXCEPTION:
 168       /* Crash occured due to CPU exception.  */
 169
 170       /* This is 68k-specific; for MIPS we'll need to interpret
 171          cpu_vector differently based on the target configuration
 172          (since CISCO core files don't seem to have the processor
 173          encoded in them).  */
 174
 175       switch (bfd_get_32 (abfd, crashinfo.cpu_vector))
 176         {
 177            /* bus error           */
 178         case 2 : abfd->tdata.cisco_core_data->sig = SIGBUS; break;
 179            /* address error       */
 180         case 3 : abfd->tdata.cisco_core_data->sig = SIGBUS; break;
 181            /* illegal instruction */
 182         case 4 : abfd->tdata.cisco_core_data->sig = SIGILL;  break;
 183            /* zero divide         */
 184         case 5 : abfd->tdata.cisco_core_data->sig = SIGFPE;  break;
 185            /* chk instruction     */
 186         case 6 : abfd->tdata.cisco_core_data->sig = SIGFPE; break;
 187            /* trapv instruction   */
 188         case 7 : abfd->tdata.cisco_core_data->sig = SIGFPE; break;
 189            /* privilege violation */
 190         case 8 : abfd->tdata.cisco_core_data->sig = SIGSEGV; break;
 191            /* trace trap          */
 192         case 9 : abfd->tdata.cisco_core_data->sig = SIGTRAP;  break;
 193            /* line 1010 emulator  */
 194         case 10: abfd->tdata.cisco_core_data->sig = SIGILL;  break;
 195            /* line 1111 emulator  */
 196         case 11: abfd->tdata.cisco_core_data->sig = SIGILL;  break;
 197
 198           /* Coprocessor protocol violation.  Using a standard MMU or FPU
 199              this cannot be triggered by software.  Call it a SIGBUS.  */
 200         case 13: abfd->tdata.cisco_core_data->sig = SIGBUS;  break;
 201
 202           /* interrupt           */
 203         case 31: abfd->tdata.cisco_core_data->sig = SIGINT;  break;
 204           /* breakpoint          */
 205         case 33: abfd->tdata.cisco_core_data->sig = SIGTRAP;  break;
 206
 207           /* floating point err  */
 208         case 48: abfd->tdata.cisco_core_data->sig = SIGFPE;  break;
 209           /* floating point err  */
 210         case 49: abfd->tdata.cisco_core_data->sig = SIGFPE;  break;
 211           /* zero divide         */
 212         case 50: abfd->tdata.cisco_core_data->sig = SIGFPE;  break;
 213           /* underflow           */
 214         case 51: abfd->tdata.cisco_core_data->sig = SIGFPE;  break;
 215           /* operand error       */
 216         case 52: abfd->tdata.cisco_core_data->sig = SIGFPE;  break;
 217            /* overflow            */
 218         case 53: abfd->tdata.cisco_core_data->sig = SIGFPE;  break;
 219           /* NAN                 */
 220         case 54: abfd->tdata.cisco_core_data->sig = SIGFPE;  break;
 221         default:
 222 #ifndef SIGEMT
 223 #define SIGEMT SIGTRAP
 224 #endif
 225           /* "software generated"*/
 226           abfd->tdata.cisco_core_data->sig = SIGEMT;
 227         }
 228       break;
 229     default:
 230       /* Unknown crash reason.  */
 231       abfd->tdata.cisco_core_data->sig = 0;
 232       break;
 233     }
 234
 235   abfd->sections = NULL;
 236   abfd->section_count = 0;
 237
 238   /* Create a ".reg" section to allow access to the saved
 239      registers. */
 240
 241   asect = (asection *) bfd_zmalloc (sizeof (asection));
 242   if (asect == NULL)
 243     goto error_return;
 244   asect->name = ".reg";
 245   asect->flags = SEC_HAS_CONTENTS;
 246   asect->vma = 0;
 247   asect->filepos = bfd_get_32 (abfd, crashinfo.registers) - rambase;
 248   /* Since we don't know the exact size of the saved register info,
 249      choose a register section size that is either the remaining part
 250      of the file, or 1024, whichever is smaller. */
 251   nread = statbuf.st_size - asect->filepos;
 252   asect->_raw_size = (nread < 1024) ? nread : 1024;
 253   asect->next = abfd->sections;
 254   abfd->sections = asect;
 255   ++abfd->section_count;
 256
 257   /* Create a ".crash" section to allow access to the saved
 258      crash information. */
 259
 260   asect = (asection *) bfd_zmalloc (sizeof (asection));
 261   if (asect == NULL)
 262     goto error_return;
 263   asect->name = ".crash";
 264   asect->flags = SEC_HAS_CONTENTS;
 265   asect->vma = 0;
 266   asect->filepos = crashinfo_offset;
 267   asect->_raw_size = sizeof (crashinfo);
 268   asect->next = abfd->sections;
 269   abfd->sections = asect;
 270   ++abfd->section_count;
 271
 272   /* Create a ".data" section that maps the entire file, which is
 273      essentially a dump of the target system's RAM. */
 274
 275   asect = (asection *) bfd_zmalloc (sizeof (asection));
 276   if (asect == NULL)
 277     goto error_return;
 278   asect->name = ".data";
 279   asect->flags = SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS;
 280   /* The size of memory is the size of the core file itself.  */
 281   asect->_raw_size = statbuf.st_size;
 282   asect->vma = rambase;
 283   asect->filepos = 0;
 284   asect->next = abfd->sections;
 285   abfd->sections = asect;
 286   ++abfd->section_count;
 287
 288   return abfd->xvec;
 289
 290   /* Get here if we have already started filling out the BFD
 291      and there is an error of some kind. */
 292
 293  error_return:
 294   {
 295     sec_ptr nextsect;
 296     for (asect = abfd->sections; asect != NULL;)
 297       {
 298         nextsect = asect->next;
 299         free (asect);
 300         asect = nextsect;
 301       }
 302     free (abfd->tdata.cisco_core_data);
 303     return NULL;
 304   }
 305 }
 306
 307 static const bfd_target *
 308 cisco_core_file_p (abfd)
 309      bfd *abfd;
 310 {
 311   int *crash_info_locp;
 312   const bfd_target *target = NULL;
 313
 314   for (crash_info_locp = crash_info_locs;
 315        *crash_info_locp != -1  &&  target == NULL;
 316        crash_info_locp++)
 317     {
 318       target = cisco_core_file_validate (abfd, *crash_info_locp);
 319     }
 320   return (target);
 321 }
 322
 323 char *
 324 cisco_core_file_failing_command (abfd)
 325      bfd *abfd;
 326 {
 327   return NULL;
 328 }
 329
 330 int
 331 cisco_core_file_failing_signal (abfd)
 332      bfd *abfd;
 333 {
 334   return abfd->tdata.cisco_core_data->sig;
 335 }
 336
 337 boolean
 338 cisco_core_file_matches_executable_p (core_bfd, exec_bfd)
 339      bfd *core_bfd;
 340      bfd *exec_bfd;
 341 {
 342   return true;
 343 }
 344 \f
 345 extern const bfd_target cisco_core_little_vec;
 346
 347 const bfd_target cisco_core_big_vec =
 348   {
 349     "cisco-ios-core-big",
 350     bfd_target_unknown_flavour,
 351     BFD_ENDIAN_BIG,             /* target byte order */
 352     BFD_ENDIAN_BIG,             /* target headers byte order */
 353     (HAS_RELOC | EXEC_P |       /* object flags */
 354      HAS_LINENO | HAS_DEBUG |
 355      HAS_SYMS | HAS_LOCALS | WP_TEXT | D_PAGED),
 356     (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_RELOC), /* section flags */
 357     0,                                                     /* symbol prefix */
 358     ' ',                                                   /* ar_pad_char */
 359     16,                                                    /* ar_max_namelen */
 360     bfd_getb64, bfd_getb_signed_64, bfd_putb64,
 361     bfd_getb32, bfd_getb_signed_32, bfd_putb32,
 362     bfd_getb16, bfd_getb_signed_16, bfd_putb16, /* data */
 363     bfd_getb64, bfd_getb_signed_64, bfd_putb64,
 364     bfd_getb32, bfd_getb_signed_32, bfd_putb32,
 365     bfd_getb16, bfd_getb_signed_16, bfd_putb16, /* hdrs */
 366
 367     {                           /* bfd_check_format */
 368      _bfd_dummy_target,         /* unknown format */
 369      _bfd_dummy_target,         /* object file */
 370      _bfd_dummy_target,         /* archive */
 371      cisco_core_file_p  /* a core file */
 372     },
 373     {                           /* bfd_set_format */
 374      bfd_false, bfd_false,
 375      bfd_false, bfd_false
 376     },
 377     {                           /* bfd_write_contents */
 378      bfd_false, bfd_false,
 379      bfd_false, bfd_false
 380     },
 381
 382        BFD_JUMP_TABLE_GENERIC (_bfd_generic),
 383        BFD_JUMP_TABLE_COPY (_bfd_generic),
 384        BFD_JUMP_TABLE_CORE (cisco),
 385        BFD_JUMP_TABLE_ARCHIVE (_bfd_noarchive),
 386        BFD_JUMP_TABLE_SYMBOLS (_bfd_nosymbols),
 387        BFD_JUMP_TABLE_RELOCS (_bfd_norelocs),
 388        BFD_JUMP_TABLE_WRITE (_bfd_generic),
 389        BFD_JUMP_TABLE_LINK (_bfd_nolink),
 390        BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic),
 391
 392     & cisco_core_little_vec,
 393
 394     (PTR) 0                     /* backend_data */
 395 };
 396
 397 const bfd_target cisco_core_little_vec =
 398   {
 399     "cisco-ios-core-little",
 400     bfd_target_unknown_flavour,
 401     BFD_ENDIAN_LITTLE,          /* target byte order */
 402     BFD_ENDIAN_LITTLE,          /* target headers byte order */
 403     (HAS_RELOC | EXEC_P |       /* object flags */
 404      HAS_LINENO | HAS_DEBUG |
 405      HAS_SYMS | HAS_LOCALS | WP_TEXT | D_PAGED),
 406     (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_RELOC), /* section flags */
 407     0,                                                     /* symbol prefix */
 408     ' ',                                                   /* ar_pad_char */
 409     16,                                                    /* ar_max_namelen */
 410     bfd_getl64, bfd_getl_signed_64, bfd_putl64,
 411     bfd_getl32, bfd_getl_signed_32, bfd_putl32,
 412     bfd_getl16, bfd_getl_signed_16, bfd_putl16, /* data */
 413     bfd_getl64, bfd_getl_signed_64, bfd_putl64,
 414     bfd_getl32, bfd_getl_signed_32, bfd_putl32,
 415     bfd_getl16, bfd_getl_signed_16, bfd_putl16, /* hdrs */
 416
 417     {                           /* bfd_check_format */
 418      _bfd_dummy_target,         /* unknown format */
 419      _bfd_dummy_target,         /* object file */
 420      _bfd_dummy_target,         /* archive */
 421      cisco_core_file_p  /* a core file */
 422     },
 423     {                           /* bfd_set_format */
 424      bfd_false, bfd_false,
 425      bfd_false, bfd_false
 426     },
 427     {                           /* bfd_write_contents */
 428      bfd_false, bfd_false,
 429      bfd_false, bfd_false
 430     },
 431
 432        BFD_JUMP_TABLE_GENERIC (_bfd_generic),
 433        BFD_JUMP_TABLE_COPY (_bfd_generic),
 434        BFD_JUMP_TABLE_CORE (cisco),
 435        BFD_JUMP_TABLE_ARCHIVE (_bfd_noarchive),
 436        BFD_JUMP_TABLE_SYMBOLS (_bfd_nosymbols),
 437        BFD_JUMP_TABLE_RELOCS (_bfd_norelocs),
 438        BFD_JUMP_TABLE_WRITE (_bfd_generic),
 439        BFD_JUMP_TABLE_LINK (_bfd_nolink),
 440        BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic),
 441
 442     &cisco_core_big_vec,
 443
 444     (PTR) 0                     /* backend_data */
 445 };