bfd/cisco-core.c

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