1 /*
2 * Copyright (c) 2004 Marcel Moolenaar
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29
30 #include <sys/param.h>
31 #include <sys/stat.h>
32 #include <sys/types.h>
33 #include <sys/ioctl.h>
34 #include <sys/resource.h>
35 #include <sys/select.h>
36 #include <sys/time.h>
37 #include <sys/wait.h>
38 #include <errno.h>
39 #include <err.h>
40 #include <inttypes.h>
41 #include <kvm.h>
42 #include <limits.h>
43 #include <paths.h>
44 #include <stdio.h>
45 #include <stdlib.h>
46 #include <string.h>
47 #include <unistd.h>
48
49 /* libgdb stuff. */
50 #include <defs.h>
51 #include <frame.h>
52 #include <frame-unwind.h>
53 #include <inferior.h>
54 #include <interps.h>
55 #include <cli-out.h>
56 #include <main.h>
57 #include <objfiles.h>
58 #include <target.h>
59 #include <top.h>
60 #include <ui-file.h>
61 #include <bfd.h>
62 #include <gdbcore.h>
63 #include <wrapper.h>
64
65 extern frame_unwind_sniffer_ftype *kgdb_sniffer_kluge;
66
67 #include "kgdb.h"
68
69 static int dumpnr;
70 static int quiet;
71 static int verbose;
72
73 static char crashdir[PATH_MAX];
74 static char *kernel;
75 static char *remote;
76 static char *vmcore;
77 static struct ui_file *parse_gdberr;
78
79 static void (*kgdb_new_objfile_chain)(struct objfile * objfile);
80
81 static void
usage(void)82 usage(void)
83 {
84
85 fprintf(stderr,
86 "usage: %s [-afqvw] [-b rate] [-d crashdir] [-c core | -n dumpnr | -r device]\n"
87 "\t[kernel [core]]\n", getprogname());
88 exit(1);
89 }
90
91 static void
kernel_from_dumpnr(int nr)92 kernel_from_dumpnr(int nr)
93 {
94 char path[PATH_MAX];
95 FILE *info;
96 char *s;
97 struct stat st;
98 int l;
99
100 /*
101 * If there's a kernel image right here in the crash directory, then
102 * use it. The kernel image is either called kernel.<nr> or is in a
103 * subdirectory kernel.<nr> and called kernel. The latter allows us
104 * to collect the modules in the same place.
105 */
106 snprintf(path, sizeof(path), "%s/kernel.%d", crashdir, nr);
107 if (stat(path, &st) == 0) {
108 if (S_ISREG(st.st_mode)) {
109 kernel = strdup(path);
110 return;
111 }
112 if (S_ISDIR(st.st_mode)) {
113 snprintf(path, sizeof(path), "%s/kernel.%d/kernel",
114 crashdir, nr);
115 if (stat(path, &st) == 0 && S_ISREG(st.st_mode)) {
116 kernel = strdup(path);
117 return;
118 }
119 }
120 }
121
122 /*
123 * No kernel image here. Parse the dump header. The kernel object
124 * directory can be found there and we probably have the kernel
125 * image still in it. The object directory may also have a kernel
126 * with debugging info (called kernel.debug). If we have a debug
127 * kernel, use it.
128 */
129 snprintf(path, sizeof(path), "%s/info.%d", crashdir, nr);
130 info = fopen(path, "r");
131 if (info == NULL) {
132 warn("%s", path);
133 return;
134 }
135 while (fgets(path, sizeof(path), info) != NULL) {
136 l = strlen(path);
137 if (l > 0 && path[l - 1] == '\n')
138 path[--l] = '\0';
139 if (strncmp(path, " ", 4) == 0) {
140 s = strchr(path, ':');
141 s = (s == NULL) ? path + 4 : s + 1;
142 l = snprintf(path, sizeof(path), "%s/kernel.debug", s);
143 if (stat(path, &st) == -1 || !S_ISREG(st.st_mode)) {
144 path[l - 6] = '\0';
145 if (stat(path, &st) == -1 ||
146 !S_ISREG(st.st_mode))
147 break;
148 }
149 kernel = strdup(path);
150 break;
151 }
152 }
153 fclose(info);
154 }
155
156 static void
kgdb_new_objfile(struct objfile * objfile)157 kgdb_new_objfile(struct objfile *objfile)
158 {
159 static int once = 1;
160
161 kld_new_objfile(objfile);
162 kgdb_trgt_new_objfile(objfile);
163
164 if (kgdb_new_objfile_chain != NULL)
165 kgdb_new_objfile_chain(objfile);
166
167 if (once && objfile != NULL && objfile == symfile_objfile) {
168 /*
169 * The initial kernel has just been loaded. Start the
170 * remote target if we have one.
171 */
172 once = 0;
173 if (remote != NULL)
174 push_remote_target (remote, 0);
175 }
176 }
177
178 /*
179 * Parse an expression and return its value. If 'quiet' is true, then
180 * any error messages from the parser are masked.
181 */
182 CORE_ADDR
kgdb_parse_1(const char * exp,int quiet)183 kgdb_parse_1(const char *exp, int quiet)
184 {
185 struct ui_file *old_stderr;
186 struct cleanup *old_chain;
187 struct expression *expr;
188 struct value *val;
189 char *s;
190 CORE_ADDR n;
191
192 old_stderr = gdb_stderr;
193 if (quiet)
194 gdb_stderr = parse_gdberr;
195 n = 0;
196 s = xstrdup(exp);
197 old_chain = make_cleanup(xfree, s);
198 if (gdb_parse_exp_1(&s, NULL, 0, &expr) && *s == '\0') {
199 make_cleanup(free_current_contents, &expr);
200 if (gdb_evaluate_expression(expr, &val))
201 n = value_as_address(val);
202 }
203 do_cleanups(old_chain);
204 gdb_stderr = old_stderr;
205 return (n);
206 }
207
208 #define MSGBUF_SEQ_TO_POS(size, seq) ((seq) % (size))
209
210 void
kgdb_dmesg(void)211 kgdb_dmesg(void)
212 {
213 CORE_ADDR bufp;
214 int size, rseq, wseq;
215 char c;
216
217 /*
218 * Display the unread portion of the message buffer. This gives the
219 * user a some initial data to work from.
220 */
221 if (quiet)
222 return;
223 bufp = kgdb_parse("msgbufp->msg_ptr");
224 size = (int)kgdb_parse("msgbufp->msg_size");
225 if (bufp == 0 || size == 0)
226 return;
227 rseq = (int)kgdb_parse("msgbufp->msg_rseq");
228 wseq = (int)kgdb_parse("msgbufp->msg_wseq");
229 rseq = MSGBUF_SEQ_TO_POS(size, rseq);
230 wseq = MSGBUF_SEQ_TO_POS(size, wseq);
231 if (rseq == wseq)
232 return;
233
234 printf("\nUnread portion of the kernel message buffer:\n");
235 while (rseq < wseq) {
236 read_memory(bufp + rseq, &c, 1);
237 putchar(c);
238 rseq++;
239 if (rseq == size)
240 rseq = 0;
241 }
242 if (c != '\n')
243 putchar('\n');
244 putchar('\n');
245 }
246
247 static void
kgdb_init(char * argv0 __unused)248 kgdb_init(char *argv0 __unused)
249 {
250
251 parse_gdberr = mem_fileopen();
252 set_prompt("(kgdb) ");
253 initialize_kgdb_target();
254 initialize_kld_target();
255 kgdb_new_objfile_chain = target_new_objfile_hook;
256 target_new_objfile_hook = kgdb_new_objfile;
257 }
258
259 /*
260 * Remote targets can support any number of syntaxes and we want to
261 * support them all with one addition: we support specifying a device
262 * node for a serial device without the "/dev/" prefix.
263 *
264 * What we do is to stat(2) the existing remote target first. If that
265 * fails, we try it with "/dev/" prepended. If that succeeds we use
266 * the resulting path, otherwise we use the original target. If
267 * either stat(2) succeeds make sure the file is either a character
268 * device or a FIFO.
269 */
270 static void
verify_remote(void)271 verify_remote(void)
272 {
273 char path[PATH_MAX];
274 struct stat st;
275
276 if (stat(remote, &st) != 0) {
277 snprintf(path, sizeof(path), "/dev/%s", remote);
278 if (stat(path, &st) != 0)
279 return;
280 free(remote);
281 remote = strdup(path);
282 }
283 if (!S_ISCHR(st.st_mode) && !S_ISFIFO(st.st_mode))
284 errx(1, "%s: not a special file, FIFO or socket", remote);
285 }
286
287 static void
add_arg(struct captured_main_args * args,char * arg)288 add_arg(struct captured_main_args *args, char *arg)
289 {
290
291 args->argc++;
292 args->argv = reallocf(args->argv, (args->argc + 1) * sizeof(char *));
293 if (args->argv == NULL)
294 err(1, "Out of memory building argument list");
295 args->argv[args->argc] = arg;
296 }
297
298 int
main(int argc,char * argv[])299 main(int argc, char *argv[])
300 {
301 char path[PATH_MAX];
302 struct stat st;
303 struct captured_main_args args;
304 char *s;
305 int a, ch;
306
307 dumpnr = -1;
308
309 strlcpy(crashdir, "/var/crash", sizeof(crashdir));
310 s = getenv("KGDB_CRASH_DIR");
311 if (s != NULL)
312 strlcpy(crashdir, s, sizeof(crashdir));
313
314 /* Convert long options into short options. */
315 for (a = 1; a < argc; a++) {
316 s = argv[a];
317 if (s[0] == '-') {
318 s++;
319 /* Long options take either 1 or 2 dashes. */
320 if (s[0] == '-')
321 s++;
322 if (strcmp(s, "quiet") == 0)
323 argv[a] = "-q";
324 else if (strcmp(s, "fullname") == 0)
325 argv[a] = "-f";
326 }
327 }
328
329 quiet = 0;
330 memset (&args, 0, sizeof args);
331 args.use_windows = 0;
332 args.interpreter_p = INTERP_CONSOLE;
333 args.argv = malloc(sizeof(char *));
334 args.argv[0] = argv[0];
335
336 while ((ch = getopt(argc, argv, "ab:c:d:fn:qr:vw")) != -1) {
337 switch (ch) {
338 case 'a':
339 annotation_level++;
340 break;
341 case 'b': {
342 int i;
343 char *p;
344
345 i = strtol(optarg, &p, 0);
346 if (*p != '\0' || p == optarg)
347 warnx("warning: could not set baud rate to `%s'.\n",
348 optarg);
349 else
350 baud_rate = i;
351 break;
352 }
353 case 'c': /* use given core file. */
354 if (vmcore != NULL) {
355 warnx("option %c: can only be specified once",
356 optopt);
357 usage();
358 /* NOTREACHED */
359 }
360 vmcore = strdup(optarg);
361 break;
362 case 'd': /* lookup dumps in given directory. */
363 strlcpy(crashdir, optarg, sizeof(crashdir));
364 break;
365 case 'f':
366 annotation_level = 1;
367 break;
368 case 'n': /* use dump with given number. */
369 dumpnr = strtol(optarg, &s, 0);
370 if (dumpnr < 0 || *s != '\0') {
371 warnx("option %c: invalid kernel dump number",
372 optopt);
373 usage();
374 /* NOTREACHED */
375 }
376 break;
377 case 'q':
378 quiet = 1;
379 add_arg(&args, "-q");
380 break;
381 case 'r': /* use given device for remote session. */
382 if (remote != NULL) {
383 warnx("option %c: can only be specified once",
384 optopt);
385 usage();
386 /* NOTREACHED */
387 }
388 remote = strdup(optarg);
389 break;
390 case 'v': /* increase verbosity. */
391 verbose++;
392 break;
393 case 'w': /* core file is writeable. */
394 add_arg(&args, "--write");
395 break;
396 case '?':
397 default:
398 usage();
399 }
400 }
401
402 if (((vmcore != NULL) ? 1 : 0) + ((dumpnr >= 0) ? 1 : 0) +
403 ((remote != NULL) ? 1 : 0) > 1) {
404 warnx("options -c, -n and -r are mutually exclusive");
405 usage();
406 /* NOTREACHED */
407 }
408
409 if (verbose > 1)
410 warnx("using %s as the crash directory", crashdir);
411
412 if (argc > optind)
413 kernel = strdup(argv[optind++]);
414
415 if (argc > optind && (dumpnr >= 0 || remote != NULL)) {
416 warnx("options -n and -r do not take a core file. Ignored");
417 optind = argc;
418 }
419
420 if (dumpnr >= 0) {
421 snprintf(path, sizeof(path), "%s/vmcore.%d", crashdir, dumpnr);
422 if (stat(path, &st) == -1)
423 err(1, "%s", path);
424 if (!S_ISREG(st.st_mode))
425 errx(1, "%s: not a regular file", path);
426 vmcore = strdup(path);
427 } else if (remote != NULL) {
428 verify_remote();
429 } else if (argc > optind) {
430 if (vmcore == NULL)
431 vmcore = strdup(argv[optind++]);
432 if (argc > optind)
433 warnx("multiple core files specified. Ignored");
434 } else if (vmcore == NULL && kernel == NULL) {
435 vmcore = strdup(_PATH_MEM);
436 kernel = strdup(getbootfile());
437 }
438
439 if (verbose) {
440 if (vmcore != NULL)
441 warnx("core file: %s", vmcore);
442 if (remote != NULL)
443 warnx("device file: %s", remote);
444 if (kernel != NULL)
445 warnx("kernel image: %s", kernel);
446 }
447
448 /* A remote target requires an explicit kernel argument. */
449 if (remote != NULL && kernel == NULL) {
450 warnx("remote debugging requires a kernel");
451 usage();
452 /* NOTREACHED */
453 }
454
455 /* If we don't have a kernel image yet, try to find one. */
456 if (kernel == NULL) {
457 if (dumpnr >= 0)
458 kernel_from_dumpnr(dumpnr);
459
460 if (kernel == NULL)
461 errx(1, "couldn't find a suitable kernel image");
462 if (verbose)
463 warnx("kernel image: %s", kernel);
464 }
465 add_arg(&args, kernel);
466
467 if (vmcore != NULL)
468 add_arg(&args, vmcore);
469
470 /* The libgdb code uses optind too. Reset it... */
471 optind = 0;
472
473 /* Terminate argv list. */
474 add_arg(&args, NULL);
475
476 init_ui_hook = kgdb_init;
477
478 kgdb_sniffer_kluge = kgdb_trgt_trapframe_sniffer;
479
480 return (gdb_main(&args));
481 }
482