bfd/cisco-core.c

   1 /* BFD back-end for CISCO crash dumps.
   2    Copyright 1994, 1997, 1999, 2000, 2001, 2002, 2004, 2005, 2006, 2007,
   3    2010, 2011
   4    Free Software Foundation, Inc.
   5
   6    This file is part of BFD, the Binary File Descriptor library.
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program; if not, write to the Free Software
  20    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  21    MA 02110-1301, USA.  */
  22
  23 #include "sysdep.h"
  24 #include "bfd.h"
  25 #include "libbfd.h"
  26 /* core_file_failing_signal returns a host signal (this probably should
  27    be fixed).  */
  28 #include <signal.h>
  29
  30 /* for MSVC builds */
  31 #ifndef SIGTRAP
  32 # define SIGTRAP 5
  33 #endif
  34 #ifndef SIGEMT
  35 # define SIGEMT 6
  36 #endif
  37 #ifndef SIGBUS
  38 # define SIGBUS 10
  39 #endif
  40 \f
  41 int crash_info_locs[] = {
  42   0x0250,       /* mips, ppc, x86, i960 */
  43   0x0400,       /* m68k, mips, x86, i960 */
  44   0x0FFC,       /* m68k, mips, ppc, x86, i960 */
  45   0x3000,       /* ppc */
  46   0x4FFC,       /* m68k */
  47   -1
  48 };
  49
  50 #define CRASH_MAGIC     0xdead1234
  51 #define MASK_ADDR(x)    ((x) & 0x0fffffff)      /* Mask crash info address */
  52
  53 typedef enum {
  54     CRASH_REASON_NOTCRASHED = 0,
  55     CRASH_REASON_EXCEPTION = 1,
  56     CRASH_REASON_CORRUPT = 2,
  57 } crashreason;
  58
  59 typedef struct {
  60   char magic[4];                /* Magic number */
  61   char version[4];              /* Version number */
  62   char reason[4];               /* Crash reason */
  63   char cpu_vector[4];           /* CPU vector for exceptions */
  64   char registers[4];            /* Pointer to saved registers */
  65   char rambase[4];              /* Base of RAM (not in V1 crash info) */
  66   char textbase[4];             /* Base of .text section (not in V3 crash info) */
  67   char database[4];             /* Base of .data section (not in V3 crash info) */
  68   char bssbase[4];              /* Base of .bss section (not in V3 crash info) */
  69 } crashinfo_external;
  70
  71 struct cisco_core_struct
  72 {
  73   int sig;
  74 };
  75
  76 static const bfd_target *cisco_core_file_validate PARAMS ((bfd *, int));
  77 static const bfd_target *cisco_core_file_p PARAMS ((bfd *));
  78 char *cisco_core_file_failing_command PARAMS ((bfd *));
  79 int cisco_core_file_failing_signal PARAMS ((bfd *));
  80 #define cisco_core_file_matches_executable_p generic_core_file_matches_executable_p
  81 #define cisco_core_file_pid _bfd_nocore_core_file_pid
  82 \f
  83 /* Examine the file for a crash info struct at the offset given by
  84    CRASH_INFO_LOC.  */
  85
  86 static const bfd_target *
  87 cisco_core_file_validate (abfd, crash_info_loc)
  88      bfd *abfd;
  89      int crash_info_loc;
  90 {
  91   char buf[4];
  92   unsigned int crashinfo_offset;
  93   crashinfo_external crashinfo;
  94   bfd_size_type nread;
  95   unsigned int magic;
  96   unsigned int version;
  97   unsigned int rambase;
  98   sec_ptr asect;
  99   struct stat statbuf;
 100   bfd_size_type amt;
 101   flagword flags;
 102
 103   if (bfd_seek (abfd, (file_ptr) crash_info_loc, SEEK_SET) != 0)
 104     return NULL;
 105
 106   nread = bfd_bread (buf, (bfd_size_type) 4, abfd);
 107   if (nread != 4)
 108     {
 109       if (bfd_get_error () != bfd_error_system_call)
 110         bfd_set_error (bfd_error_wrong_format);
 111       return NULL;
 112     }
 113   crashinfo_offset = MASK_ADDR (bfd_get_32 (abfd, buf));
 114
 115   if (bfd_seek (abfd, (file_ptr) crashinfo_offset, SEEK_SET) != 0)
 116     {
 117       /* Most likely we failed because of a bogus (huge) offset */
 118       bfd_set_error (bfd_error_wrong_format);
 119       return NULL;
 120     }
 121
 122   nread = bfd_bread (&crashinfo, (bfd_size_type) sizeof (crashinfo), abfd);
 123   if (nread != sizeof (crashinfo))
 124     {
 125       if (bfd_get_error () != bfd_error_system_call)
 126         bfd_set_error (bfd_error_wrong_format);
 127       return NULL;
 128     }
 129
 130   if (bfd_stat (abfd, &statbuf) < 0)
 131     {
 132       bfd_set_error (bfd_error_system_call);
 133       return NULL;
 134     }
 135
 136   magic = bfd_get_32 (abfd, crashinfo.magic);
 137   if (magic != CRASH_MAGIC)
 138     {
 139       bfd_set_error (bfd_error_wrong_format);
 140       return NULL;
 141     }
 142
 143   version = bfd_get_32 (abfd, crashinfo.version);
 144   if (version == 0)
 145     {
 146       bfd_set_error (bfd_error_wrong_format);
 147       return NULL;
 148     }
 149   else if (version == 1)
 150     {
 151       /* V1 core dumps don't specify the dump base, assume 0 */
 152       rambase = 0;
 153     }
 154   else
 155     {
 156       rambase = bfd_get_32 (abfd, crashinfo.rambase);
 157     }
 158
 159   /* OK, we believe you.  You're a core file.  */
 160
 161   amt = sizeof (struct cisco_core_struct);
 162   abfd->tdata.cisco_core_data = (struct cisco_core_struct *) bfd_zmalloc (amt);
 163   if (abfd->tdata.cisco_core_data == NULL)
 164     return NULL;
 165
 166   switch ((crashreason) bfd_get_32 (abfd, crashinfo.reason))
 167     {
 168     case CRASH_REASON_NOTCRASHED:
 169       /* Crash file probably came from write core.  */
 170       abfd->tdata.cisco_core_data->sig = 0;
 171       break;
 172     case CRASH_REASON_CORRUPT:
 173       /* The crash context area was corrupt -- proceed with caution.
 174          We have no way of passing this information back to the caller.  */
 175       abfd->tdata.cisco_core_data->sig = 0;
 176       break;
 177     case CRASH_REASON_EXCEPTION:
 178       /* Crash occured due to CPU exception.  */
 179
 180       /* This is 68k-specific; for MIPS we'll need to interpret
 181          cpu_vector differently based on the target configuration
 182          (since CISCO core files don't seem to have the processor
 183          encoded in them).  */
 184
 185       switch (bfd_get_32 (abfd, crashinfo.cpu_vector))
 186         {
 187            /* bus error           */
 188         case 2 : abfd->tdata.cisco_core_data->sig = SIGBUS; break;
 189            /* address error       */
 190         case 3 : abfd->tdata.cisco_core_data->sig = SIGBUS; break;
 191            /* illegal instruction */
 192         case 4 : abfd->tdata.cisco_core_data->sig = SIGILL;  break;
 193            /* zero divide         */
 194         case 5 : abfd->tdata.cisco_core_data->sig = SIGFPE;  break;
 195            /* chk instruction     */
 196         case 6 : abfd->tdata.cisco_core_data->sig = SIGFPE; break;
 197            /* trapv instruction   */
 198         case 7 : abfd->tdata.cisco_core_data->sig = SIGFPE; break;
 199            /* privilege violation */
 200         case 8 : abfd->tdata.cisco_core_data->sig = SIGSEGV; break;
 201            /* trace trap          */
 202         case 9 : abfd->tdata.cisco_core_data->sig = SIGTRAP;  break;
 203            /* line 1010 emulator  */
 204         case 10: abfd->tdata.cisco_core_data->sig = SIGILL;  break;
 205            /* line 1111 emulator  */
 206         case 11: abfd->tdata.cisco_core_data->sig = SIGILL;  break;
 207
 208           /* Coprocessor protocol violation.  Using a standard MMU or FPU
 209              this cannot be triggered by software.  Call it a SIGBUS.  */
 210         case 13: abfd->tdata.cisco_core_data->sig = SIGBUS;  break;
 211
 212           /* interrupt           */
 213         case 31: abfd->tdata.cisco_core_data->sig = SIGINT;  break;
 214           /* breakpoint          */
 215         case 33: abfd->tdata.cisco_core_data->sig = SIGTRAP;  break;
 216
 217           /* floating point err  */
 218         case 48: abfd->tdata.cisco_core_data->sig = SIGFPE;  break;
 219           /* floating point err  */
 220         case 49: abfd->tdata.cisco_core_data->sig = SIGFPE;  break;
 221           /* zero divide         */
 222         case 50: abfd->tdata.cisco_core_data->sig = SIGFPE;  break;
 223           /* underflow           */
 224         case 51: abfd->tdata.cisco_core_data->sig = SIGFPE;  break;
 225           /* operand error       */
 226         case 52: abfd->tdata.cisco_core_data->sig = SIGFPE;  break;
 227            /* overflow            */
 228         case 53: abfd->tdata.cisco_core_data->sig = SIGFPE;  break;
 229           /* NAN                 */
 230         case 54: abfd->tdata.cisco_core_data->sig = SIGFPE;  break;
 231         default:
 232 #ifndef SIGEMT
 233 #define SIGEMT SIGTRAP
 234 #endif
 235           /* "software generated"*/
 236           abfd->tdata.cisco_core_data->sig = SIGEMT;
 237         }
 238       break;
 239     default:
 240       /* Unknown crash reason.  */
 241       abfd->tdata.cisco_core_data->sig = 0;
 242       break;
 243     }
 244
 245   /* Create a ".data" section that maps the entire file, which is
 246      essentially a dump of the target system's RAM.  */
 247
 248   flags = SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS;
 249   asect = bfd_make_section_anyway_with_flags (abfd, ".data", flags);
 250   if (asect == NULL)
 251     goto error_return;
 252   /* The size of memory is the size of the core file itself.  */
 253   asect->size = statbuf.st_size;
 254   asect->vma = rambase;
 255   asect->filepos = 0;
 256
 257   /* Create a ".crash" section to allow access to the saved
 258      crash information.  */
 259
 260   flags = SEC_HAS_CONTENTS;
 261   asect = bfd_make_section_anyway_with_flags (abfd, ".crash", flags);
 262   if (asect == NULL)
 263     goto error_return;
 264   asect->vma = 0;
 265   asect->filepos = crashinfo_offset;
 266   asect->size = sizeof (crashinfo);
 267
 268   /* Create a ".reg" section to allow access to the saved
 269      registers.  */
 270
 271   asect = bfd_make_section_anyway_with_flags (abfd, ".reg", flags);
 272   if (asect == NULL)
 273     goto error_return;
 274   asect->vma = 0;
 275   asect->filepos = bfd_get_32 (abfd, crashinfo.registers) - rambase;
 276   /* Since we don't know the exact size of the saved register info,
 277      choose a register section size that is either the remaining part
 278      of the file, or 1024, whichever is smaller.  */
 279   nread = statbuf.st_size - asect->filepos;
 280   asect->size = (nread < 1024) ? nread : 1024;
 281
 282   return abfd->xvec;
 283
 284   /* Get here if we have already started filling out the BFD
 285      and there is an error of some kind.  */
 286
 287  error_return:
 288   bfd_release (abfd, abfd->tdata.any);
 289   abfd->tdata.any = NULL;
 290   bfd_section_list_clear (abfd);
 291   return NULL;
 292 }
 293
 294 static const bfd_target *
 295 cisco_core_file_p (abfd)
 296      bfd *abfd;
 297 {
 298   int *crash_info_locp;
 299   const bfd_target *target = NULL;
 300
 301   for (crash_info_locp = crash_info_locs;
 302        *crash_info_locp != -1  &&  target == NULL;
 303        crash_info_locp++)
 304     {
 305       target = cisco_core_file_validate (abfd, *crash_info_locp);
 306     }
 307   return (target);
 308 }
 309
 310 char *
 311 cisco_core_file_failing_command (abfd)
 312      bfd *abfd ATTRIBUTE_UNUSED;
 313 {
 314   return NULL;
 315 }
 316
 317 int
 318 cisco_core_file_failing_signal (abfd)
 319      bfd *abfd ATTRIBUTE_UNUSED;
 320 {
 321   return abfd->tdata.cisco_core_data->sig;
 322 }
 323 \f
 324 extern const bfd_target cisco_core_little_vec;
 325
 326 const bfd_target cisco_core_big_vec =
 327   {
 328     "cisco-ios-core-big",
 329     bfd_target_unknown_flavour,
 330     BFD_ENDIAN_BIG,             /* target byte order */
 331     BFD_ENDIAN_BIG,             /* target headers byte order */
 332     (HAS_RELOC | EXEC_P |       /* object flags */
 333      HAS_LINENO | HAS_DEBUG |
 334      HAS_SYMS | HAS_LOCALS | WP_TEXT | D_PAGED),
 335     (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_RELOC), /* section flags */
 336     0,                          /* symbol prefix */
 337     ' ',                        /* ar_pad_char */
 338     16,                         /* ar_max_namelen */
 339     0,                          /* match priority.  */
 340     bfd_getb64, bfd_getb_signed_64, bfd_putb64,
 341     bfd_getb32, bfd_getb_signed_32, bfd_putb32,
 342     bfd_getb16, bfd_getb_signed_16, bfd_putb16, /* data */
 343     bfd_getb64, bfd_getb_signed_64, bfd_putb64,
 344     bfd_getb32, bfd_getb_signed_32, bfd_putb32,
 345     bfd_getb16, bfd_getb_signed_16, bfd_putb16, /* hdrs */
 346
 347     {                           /* bfd_check_format */
 348      _bfd_dummy_target,         /* unknown format */
 349      _bfd_dummy_target,         /* object file */
 350      _bfd_dummy_target,         /* archive */
 351      cisco_core_file_p  /* a core file */
 352     },
 353     {                           /* bfd_set_format */
 354      bfd_false, bfd_false,
 355      bfd_false, bfd_false
 356     },
 357     {                           /* bfd_write_contents */
 358      bfd_false, bfd_false,
 359      bfd_false, bfd_false
 360     },
 361
 362        BFD_JUMP_TABLE_GENERIC (_bfd_generic),
 363        BFD_JUMP_TABLE_COPY (_bfd_generic),
 364        BFD_JUMP_TABLE_CORE (cisco),
 365        BFD_JUMP_TABLE_ARCHIVE (_bfd_noarchive),
 366        BFD_JUMP_TABLE_SYMBOLS (_bfd_nosymbols),
 367        BFD_JUMP_TABLE_RELOCS (_bfd_norelocs),
 368        BFD_JUMP_TABLE_WRITE (_bfd_generic),
 369        BFD_JUMP_TABLE_LINK (_bfd_nolink),
 370        BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic),
 371
 372     & cisco_core_little_vec,
 373
 374     (PTR) 0                     /* backend_data */
 375 };
 376
 377 const bfd_target cisco_core_little_vec =
 378   {
 379     "cisco-ios-core-little",
 380     bfd_target_unknown_flavour,
 381     BFD_ENDIAN_LITTLE,          /* target byte order */
 382     BFD_ENDIAN_LITTLE,          /* target headers byte order */
 383     (HAS_RELOC | EXEC_P |       /* object flags */
 384      HAS_LINENO | HAS_DEBUG |
 385      HAS_SYMS | HAS_LOCALS | WP_TEXT | D_PAGED),
 386     (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_RELOC), /* section flags */
 387     0,                                                     /* symbol prefix */
 388     ' ',                                                   /* ar_pad_char */
 389     16,                                                    /* ar_max_namelen */
 390     0,                          /* match_priority */
 391     bfd_getl64, bfd_getl_signed_64, bfd_putl64,
 392     bfd_getl32, bfd_getl_signed_32, bfd_putl32,
 393     bfd_getl16, bfd_getl_signed_16, bfd_putl16, /* data */
 394     bfd_getl64, bfd_getl_signed_64, bfd_putl64,
 395     bfd_getl32, bfd_getl_signed_32, bfd_putl32,
 396     bfd_getl16, bfd_getl_signed_16, bfd_putl16, /* hdrs */
 397
 398     {                           /* bfd_check_format */
 399      _bfd_dummy_target,         /* unknown format */
 400      _bfd_dummy_target,         /* object file */
 401      _bfd_dummy_target,         /* archive */
 402      cisco_core_file_p  /* a core file */
 403     },
 404     {                           /* bfd_set_format */
 405      bfd_false, bfd_false,
 406      bfd_false, bfd_false
 407     },
 408     {                           /* bfd_write_contents */
 409      bfd_false, bfd_false,
 410      bfd_false, bfd_false
 411     },
 412
 413        BFD_JUMP_TABLE_GENERIC (_bfd_generic),
 414        BFD_JUMP_TABLE_COPY (_bfd_generic),
 415        BFD_JUMP_TABLE_CORE (cisco),
 416        BFD_JUMP_TABLE_ARCHIVE (_bfd_noarchive),
 417        BFD_JUMP_TABLE_SYMBOLS (_bfd_nosymbols),
 418        BFD_JUMP_TABLE_RELOCS (_bfd_norelocs),
 419        BFD_JUMP_TABLE_WRITE (_bfd_generic),
 420        BFD_JUMP_TABLE_LINK (_bfd_nolink),
 421        BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic),
 422
 423     &cisco_core_big_vec,
 424
 425     (PTR) 0                     /* backend_data */
 426 };