1/* BFD back-end for CISCO crash dumps. 2 Copyright (C) 1994-2017 Free Software Foundation, Inc. 3 4 This file is part of BFD, the Binary File Descriptor library. 5 6 This program is free software; you can redistribute it and/or modify 7 it under the terms of the GNU General Public License as published by 8 the Free Software Foundation; either version 3 of the License, or 9 (at your option) any later version. 10 11 This program is distributed in the hope that it will be useful, 12 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 GNU General Public License for more details. 15 16 You should have received a copy of the GNU General Public License 17 along with this program; if not, write to the Free Software 18 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, 19 MA 02110-1301, USA. */ 20 21#include "sysdep.h" 22#include "bfd.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 39int crash_info_locs[] = 40{ 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 52typedef enum 53{ 54 CRASH_REASON_NOTCRASHED = 0, 55 CRASH_REASON_EXCEPTION = 1, 56 CRASH_REASON_CORRUPT = 2, 57} crashreason; 58 59typedef struct 60{ 61 char magic[4]; /* Magic number */ 62 char version[4]; /* Version number */ 63 char reason[4]; /* Crash reason */ 64 char cpu_vector[4]; /* CPU vector for exceptions */ 65 char registers[4]; /* Pointer to saved registers */ 66 char rambase[4]; /* Base of RAM (not in V1 crash info) */ 67 char textbase[4]; /* Base of .text section (not in V3 crash info) */ 68 char database[4]; /* Base of .data section (not in V3 crash info) */ 69 char bssbase[4]; /* Base of .bss section (not in V3 crash info) */ 70} crashinfo_external; 71 72struct cisco_core_struct 73{ 74 int sig; 75}; 76 77#define cisco_core_file_matches_executable_p generic_core_file_matches_executable_p 78#define cisco_core_file_pid _bfd_nocore_core_file_pid 79 80/* Examine the file for a crash info struct at the offset given by 81 CRASH_INFO_LOC. */ 82 83static const bfd_target * 84cisco_core_file_validate (bfd *abfd, int crash_info_loc) 85{ 86 char buf[4]; 87 unsigned int crashinfo_offset; 88 crashinfo_external crashinfo; 89 bfd_size_type nread; 90 unsigned int magic; 91 unsigned int version; 92 unsigned int rambase; 93 sec_ptr asect; 94 struct stat statbuf; 95 bfd_size_type amt; 96 flagword flags; 97 98 if (bfd_seek (abfd, (file_ptr) crash_info_loc, SEEK_SET) != 0) 99 return NULL; 100 101 nread = bfd_bread (buf, (bfd_size_type) 4, abfd); 102 if (nread != 4) 103 { 104 if (bfd_get_error () != bfd_error_system_call) 105 bfd_set_error (bfd_error_wrong_format); 106 return NULL; 107 } 108 crashinfo_offset = MASK_ADDR (bfd_get_32 (abfd, buf)); 109 110 if (bfd_seek (abfd, (file_ptr) crashinfo_offset, SEEK_SET) != 0) 111 { 112 /* Most likely we failed because of a bogus (huge) offset */ 113 bfd_set_error (bfd_error_wrong_format); 114 return NULL; 115 } 116 117 nread = bfd_bread (&crashinfo, (bfd_size_type) sizeof (crashinfo), abfd); 118 if (nread != sizeof (crashinfo)) 119 { 120 if (bfd_get_error () != bfd_error_system_call) 121 bfd_set_error (bfd_error_wrong_format); 122 return NULL; 123 } 124 125 if (bfd_stat (abfd, &statbuf) < 0) 126 { 127 bfd_set_error (bfd_error_system_call); 128 return NULL; 129 } 130 131 magic = bfd_get_32 (abfd, crashinfo.magic); 132 if (magic != CRASH_MAGIC) 133 { 134 bfd_set_error (bfd_error_wrong_format); 135 return NULL; 136 } 137 138 version = bfd_get_32 (abfd, crashinfo.version); 139 if (version == 0) 140 { 141 bfd_set_error (bfd_error_wrong_format); 142 return NULL; 143 } 144 else if (version == 1) 145 { 146 /* V1 core dumps don't specify the dump base, assume 0 */ 147 rambase = 0; 148 } 149 else 150 { 151 rambase = bfd_get_32 (abfd, crashinfo.rambase); 152 } 153 154 /* OK, we believe you. You're a core file. */ 155 156 amt = sizeof (struct cisco_core_struct); 157 abfd->tdata.cisco_core_data = (struct cisco_core_struct *) bfd_zmalloc (amt); 158 if (abfd->tdata.cisco_core_data == NULL) 159 return NULL; 160 161 switch ((crashreason) bfd_get_32 (abfd, crashinfo.reason)) 162 { 163 case CRASH_REASON_NOTCRASHED: 164 /* Crash file probably came from write core. */ 165 abfd->tdata.cisco_core_data->sig = 0; 166 break; 167 case CRASH_REASON_CORRUPT: 168 /* The crash context area was corrupt -- proceed with caution. 169 We have no way of passing this information back to the caller. */ 170 abfd->tdata.cisco_core_data->sig = 0; 171 break; 172 case CRASH_REASON_EXCEPTION: 173 /* Crash occured due to CPU exception. */ 174 175 /* This is 68k-specific; for MIPS we'll need to interpret 176 cpu_vector differently based on the target configuration 177 (since CISCO core files don't seem to have the processor 178 encoded in them). */ 179 180 switch (bfd_get_32 (abfd, crashinfo.cpu_vector)) 181 { 182 /* bus error */ 183 case 2 : abfd->tdata.cisco_core_data->sig = SIGBUS; break; 184 /* address error */ 185 case 3 : abfd->tdata.cisco_core_data->sig = SIGBUS; break; 186 /* illegal instruction */ 187 case 4 : abfd->tdata.cisco_core_data->sig = SIGILL; break; 188 /* zero divide */ 189 case 5 : abfd->tdata.cisco_core_data->sig = SIGFPE; break; 190 /* chk instruction */ 191 case 6 : abfd->tdata.cisco_core_data->sig = SIGFPE; break; 192 /* trapv instruction */ 193 case 7 : abfd->tdata.cisco_core_data->sig = SIGFPE; break; 194 /* privilege violation */ 195 case 8 : abfd->tdata.cisco_core_data->sig = SIGSEGV; break; 196 /* trace trap */ 197 case 9 : abfd->tdata.cisco_core_data->sig = SIGTRAP; break; 198 /* line 1010 emulator */ 199 case 10: abfd->tdata.cisco_core_data->sig = SIGILL; break; 200 /* line 1111 emulator */ 201 case 11: abfd->tdata.cisco_core_data->sig = SIGILL; break; 202 203 /* Coprocessor protocol violation. Using a standard MMU or FPU 204 this cannot be triggered by software. Call it a SIGBUS. */ 205 case 13: abfd->tdata.cisco_core_data->sig = SIGBUS; break; 206 207 /* interrupt */ 208 case 31: abfd->tdata.cisco_core_data->sig = SIGINT; break; 209 /* breakpoint */ 210 case 33: abfd->tdata.cisco_core_data->sig = SIGTRAP; break; 211 212 /* floating point err */ 213 case 48: abfd->tdata.cisco_core_data->sig = SIGFPE; break; 214 /* floating point err */ 215 case 49: abfd->tdata.cisco_core_data->sig = SIGFPE; break; 216 /* zero divide */ 217 case 50: abfd->tdata.cisco_core_data->sig = SIGFPE; break; 218 /* underflow */ 219 case 51: abfd->tdata.cisco_core_data->sig = SIGFPE; break; 220 /* operand error */ 221 case 52: abfd->tdata.cisco_core_data->sig = SIGFPE; break; 222 /* overflow */ 223 case 53: abfd->tdata.cisco_core_data->sig = SIGFPE; break; 224 /* NAN */ 225 case 54: abfd->tdata.cisco_core_data->sig = SIGFPE; break; 226 default: 227#ifndef SIGEMT 228#define SIGEMT SIGTRAP 229#endif 230 /* "software generated"*/ 231 abfd->tdata.cisco_core_data->sig = SIGEMT; 232 } 233 break; 234 default: 235 /* Unknown crash reason. */ 236 abfd->tdata.cisco_core_data->sig = 0; 237 break; 238 } 239 240 /* Create a ".data" section that maps the entire file, which is 241 essentially a dump of the target system's RAM. */ 242 243 flags = SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS; 244 asect = bfd_make_section_anyway_with_flags (abfd, ".data", flags); 245 if (asect == NULL) 246 goto error_return; 247 /* The size of memory is the size of the core file itself. */ 248 asect->size = statbuf.st_size; 249 asect->vma = rambase; 250 asect->filepos = 0; 251 252 /* Create a ".crash" section to allow access to the saved 253 crash information. */ 254 255 flags = SEC_HAS_CONTENTS; 256 asect = bfd_make_section_anyway_with_flags (abfd, ".crash", flags); 257 if (asect == NULL) 258 goto error_return; 259 asect->vma = 0; 260 asect->filepos = crashinfo_offset; 261 asect->size = sizeof (crashinfo); 262 263 /* Create a ".reg" section to allow access to the saved 264 registers. */ 265 266 asect = bfd_make_section_anyway_with_flags (abfd, ".reg", flags); 267 if (asect == NULL) 268 goto error_return; 269 asect->vma = 0; 270 asect->filepos = bfd_get_32 (abfd, crashinfo.registers) - rambase; 271 /* Since we don't know the exact size of the saved register info, 272 choose a register section size that is either the remaining part 273 of the file, or 1024, whichever is smaller. */ 274 nread = statbuf.st_size - asect->filepos; 275 asect->size = (nread < 1024) ? nread : 1024; 276 277 return abfd->xvec; 278 279 /* Get here if we have already started filling out the BFD 280 and there is an error of some kind. */ 281 282 error_return: 283 bfd_release (abfd, abfd->tdata.any); 284 abfd->tdata.any = NULL; 285 bfd_section_list_clear (abfd); 286 return NULL; 287} 288 289static const bfd_target * 290cisco_core_file_p (bfd *abfd) 291{ 292 int *crash_info_locp; 293 const bfd_target *target = NULL; 294 295 for (crash_info_locp = crash_info_locs; 296 *crash_info_locp != -1 && target == NULL; 297 crash_info_locp++) 298 { 299 target = cisco_core_file_validate (abfd, *crash_info_locp); 300 } 301 return (target); 302} 303 304static char * 305cisco_core_file_failing_command (bfd *abfd ATTRIBUTE_UNUSED) 306{ 307 return NULL; 308} 309 310static int 311cisco_core_file_failing_signal (bfd *abfd ATTRIBUTE_UNUSED) 312{ 313 return abfd->tdata.cisco_core_data->sig; 314} 315 316extern const bfd_target core_cisco_le_vec; 317 318const bfd_target core_cisco_be_vec = 319{ 320 "cisco-ios-core-big", 321 bfd_target_unknown_flavour, 322 BFD_ENDIAN_BIG, /* target byte order */ 323 BFD_ENDIAN_BIG, /* target headers byte order */ 324 (HAS_RELOC | EXEC_P | /* object flags */ 325 HAS_LINENO | HAS_DEBUG | 326 HAS_SYMS | HAS_LOCALS | WP_TEXT | D_PAGED), 327 (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_RELOC), /* section flags */ 328 0, /* symbol prefix */ 329 ' ', /* ar_pad_char */ 330 16, /* ar_max_namelen */ 331 0, /* match priority. */ 332 bfd_getb64, bfd_getb_signed_64, bfd_putb64, 333 bfd_getb32, bfd_getb_signed_32, bfd_putb32, 334 bfd_getb16, bfd_getb_signed_16, bfd_putb16, /* data */ 335 bfd_getb64, bfd_getb_signed_64, bfd_putb64, 336 bfd_getb32, bfd_getb_signed_32, bfd_putb32, 337 bfd_getb16, bfd_getb_signed_16, bfd_putb16, /* hdrs */ 338 339 { /* bfd_check_format */ 340 _bfd_dummy_target, /* unknown format */ 341 _bfd_dummy_target, /* object file */ 342 _bfd_dummy_target, /* archive */ 343 cisco_core_file_p /* a core file */ 344 }, 345 { /* bfd_set_format */ 346 bfd_false, bfd_false, 347 bfd_false, bfd_false 348 }, 349 { /* bfd_write_contents */ 350 bfd_false, bfd_false, 351 bfd_false, bfd_false 352 }, 353 354 BFD_JUMP_TABLE_GENERIC (_bfd_generic), 355 BFD_JUMP_TABLE_COPY (_bfd_generic), 356 BFD_JUMP_TABLE_CORE (cisco), 357 BFD_JUMP_TABLE_ARCHIVE (_bfd_noarchive), 358 BFD_JUMP_TABLE_SYMBOLS (_bfd_nosymbols), 359 BFD_JUMP_TABLE_RELOCS (_bfd_norelocs), 360 BFD_JUMP_TABLE_WRITE (_bfd_generic), 361 BFD_JUMP_TABLE_LINK (_bfd_nolink), 362 BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic), 363 364 & core_cisco_le_vec, 365 366 NULL /* backend_data */ 367}; 368 369const bfd_target core_cisco_le_vec = 370{ 371 "cisco-ios-core-little", 372 bfd_target_unknown_flavour, 373 BFD_ENDIAN_LITTLE, /* target byte order */ 374 BFD_ENDIAN_LITTLE, /* target headers byte order */ 375 (HAS_RELOC | EXEC_P | /* object flags */ 376 HAS_LINENO | HAS_DEBUG | 377 HAS_SYMS | HAS_LOCALS | WP_TEXT | D_PAGED), 378 (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_RELOC), /* section flags */ 379 0, /* symbol prefix */ 380 ' ', /* ar_pad_char */ 381 16, /* ar_max_namelen */ 382 0, /* match_priority */ 383 bfd_getl64, bfd_getl_signed_64, bfd_putl64, 384 bfd_getl32, bfd_getl_signed_32, bfd_putl32, 385 bfd_getl16, bfd_getl_signed_16, bfd_putl16, /* data */ 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, /* hdrs */ 389 390 { /* bfd_check_format */ 391 _bfd_dummy_target, /* unknown format */ 392 _bfd_dummy_target, /* object file */ 393 _bfd_dummy_target, /* archive */ 394 cisco_core_file_p /* a core file */ 395 }, 396 { /* bfd_set_format */ 397 bfd_false, bfd_false, 398 bfd_false, bfd_false 399 }, 400 { /* bfd_write_contents */ 401 bfd_false, bfd_false, 402 bfd_false, bfd_false 403 }, 404 405 BFD_JUMP_TABLE_GENERIC (_bfd_generic), 406 BFD_JUMP_TABLE_COPY (_bfd_generic), 407 BFD_JUMP_TABLE_CORE (cisco), 408 BFD_JUMP_TABLE_ARCHIVE (_bfd_noarchive), 409 BFD_JUMP_TABLE_SYMBOLS (_bfd_nosymbols), 410 BFD_JUMP_TABLE_RELOCS (_bfd_norelocs), 411 BFD_JUMP_TABLE_WRITE (_bfd_generic), 412 BFD_JUMP_TABLE_LINK (_bfd_nolink), 413 BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic), 414 415 &core_cisco_be_vec, 416 417 NULL /* backend_data */ 418}; 419