1 /* BFD back-end for CISCO crash dumps.
2 Copyright (C) 1994-2023 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
39 int 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
52 typedef enum
53 {
54 CRASH_REASON_NOTCRASHED = 0,
55 CRASH_REASON_EXCEPTION = 1,
56 CRASH_REASON_CORRUPT = 2,
57 } crashreason;
58
59 typedef 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
72 struct 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
83 static bfd_cleanup
84 cisco_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 size_t 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 _bfd_no_cleanup;
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
289 static bfd_cleanup
290 cisco_core_file_p (bfd *abfd)
291 {
292 int *crash_info_locp;
293 bfd_cleanup cleanup = NULL;
294
295 for (crash_info_locp = crash_info_locs;
296 *crash_info_locp != -1 && cleanup == NULL;
297 crash_info_locp++)
298 {
299 cleanup = cisco_core_file_validate (abfd, *crash_info_locp);
300 }
301 return cleanup;
302 }
303
304 static char *
305 cisco_core_file_failing_command (bfd *abfd ATTRIBUTE_UNUSED)
306 {
307 return NULL;
308 }
309
310 static int
311 cisco_core_file_failing_signal (bfd *abfd ATTRIBUTE_UNUSED)
312 {
313 return abfd->tdata.cisco_core_data->sig;
314 }
315
316 extern const bfd_target core_cisco_le_vec;
317
318 const 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 TARGET_KEEP_UNUSED_SECTION_SYMBOLS, /* keep unused section symbols. */
333 bfd_getb64, bfd_getb_signed_64, bfd_putb64,
334 bfd_getb32, bfd_getb_signed_32, bfd_putb32,
335 bfd_getb16, bfd_getb_signed_16, bfd_putb16, /* data */
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, /* hdrs */
339
340 { /* bfd_check_format */
341 _bfd_dummy_target, /* unknown format */
342 _bfd_dummy_target, /* object file */
343 _bfd_dummy_target, /* archive */
344 cisco_core_file_p /* a core file */
345 },
346 { /* bfd_set_format */
347 _bfd_bool_bfd_false_error,
348 _bfd_bool_bfd_false_error,
349 _bfd_bool_bfd_false_error,
350 _bfd_bool_bfd_false_error
351 },
352 { /* bfd_write_contents */
353 _bfd_bool_bfd_false_error,
354 _bfd_bool_bfd_false_error,
355 _bfd_bool_bfd_false_error,
356 _bfd_bool_bfd_false_error
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 &core_cisco_le_vec,
370
371 NULL /* backend_data */
372 };
373
374 const bfd_target core_cisco_le_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 0, /* match_priority */
388 TARGET_KEEP_UNUSED_SECTION_SYMBOLS, /* keep unused section symbols. */
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, /* data */
392 bfd_getl64, bfd_getl_signed_64, bfd_putl64,
393 bfd_getl32, bfd_getl_signed_32, bfd_putl32,
394 bfd_getl16, bfd_getl_signed_16, bfd_putl16, /* hdrs */
395
396 { /* bfd_check_format */
397 _bfd_dummy_target, /* unknown format */
398 _bfd_dummy_target, /* object file */
399 _bfd_dummy_target, /* archive */
400 cisco_core_file_p /* a core file */
401 },
402 { /* bfd_set_format */
403 _bfd_bool_bfd_false_error,
404 _bfd_bool_bfd_false_error,
405 _bfd_bool_bfd_false_error,
406 _bfd_bool_bfd_false_error
407 },
408 { /* bfd_write_contents */
409 _bfd_bool_bfd_false_error,
410 _bfd_bool_bfd_false_error,
411 _bfd_bool_bfd_false_error,
412 _bfd_bool_bfd_false_error
413 },
414
415 BFD_JUMP_TABLE_GENERIC (_bfd_generic),
416 BFD_JUMP_TABLE_COPY (_bfd_generic),
417 BFD_JUMP_TABLE_CORE (cisco),
418 BFD_JUMP_TABLE_ARCHIVE (_bfd_noarchive),
419 BFD_JUMP_TABLE_SYMBOLS (_bfd_nosymbols),
420 BFD_JUMP_TABLE_RELOCS (_bfd_norelocs),
421 BFD_JUMP_TABLE_WRITE (_bfd_generic),
422 BFD_JUMP_TABLE_LINK (_bfd_nolink),
423 BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic),
424
425 &core_cisco_be_vec,
426
427 NULL /* backend_data */
428 };