bfd/cisco-core.c

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