bfd/cisco-core.c

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