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 * $FreeBSD: src/gnu/usr.bin/gdb/kgdb/main.c,v 1.16 2008/04/29 20:32:45 jhb Exp $
27 */
28
29 #include <sys/cdefs.h>
30
31 #include <sys/param.h>
32 #include <sys/stat.h>
33 #include <sys/types.h>
34 #include <sys/ioctl.h>
35 #include <sys/resource.h>
36 #include <sys/select.h>
37 #include <sys/time.h>
38 #include <sys/wait.h>
39 #include <errno.h>
40 #include <err.h>
41 #include <inttypes.h>
42 #include <kvm.h>
43 #include <limits.h>
44 #include <paths.h>
45 #include <stdio.h>
46 #include <stdlib.h>
47 #include <string.h>
48 #include <unistd.h>
49
50 /* libgdb stuff. */
51 #include <defs.h>
52 #include <frame.h>
53 #include <frame-unwind.h>
54 #include <inferior.h>
55 #include <interps.h>
56 #include <cli-out.h>
57 #include <main.h>
58 #include <gdbcmd.h>
59 #include <objfiles.h>
60 #include <target.h>
61 #include <top.h>
62 #include <ui-file.h>
63 #include <bfd.h>
64 #include <gdbcore.h>
65 #include <exceptions.h>
66 #include <observer.h>
67 #include <arch-utils.h>
68
69 #include "kgdb.h"
70
71 static int dumpnr;
72 static int quiet;
73 static int verbose;
74
75 static char crashdir[PATH_MAX - 24]; /* allow for appending filenames */
76 static char *kernel;
77 static char *remote;
78 static char *vmcore;
79 static struct ui_file *parse_gdberr;
80
81 static void
usage(void)82 usage(void)
83 {
84
85 fprintf(stderr,
86 "usage: %s [-afqtvw] [-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 kern.<nr> or is in a
103 * subdirectory kern.<nr> and called kernel. The latter allows us
104 * to collect the modules in the same place.
105 */
106 snprintf(path, sizeof(path), "%s/kern.%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/kern.%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 if (once && objfile != NULL && objfile == symfile_objfile) {
162 char *buf;
163
164 /*
165 * The initial kernel has just been loaded. Start the
166 * remote target if we have one or attach to the core.
167 */
168 once = 0;
169
170 if (remote != NULL)
171 asprintf(&buf, "target remote %s", remote);
172 else if (vmcore != NULL)
173 asprintf(&buf, "target kernel %s", vmcore);
174
175 if (buf != NULL) {
176 execute_command(buf, 0);
177 free(buf);
178 }
179 }
180 }
181
182 int
gdb_parse_exp_1(const char ** stringptr,struct block * block,int comma,struct expression ** expression)183 gdb_parse_exp_1 (const char **stringptr, struct block *block, int comma,
184 struct expression **expression)
185 {
186 volatile struct gdb_exception except;
187 CORE_ADDR pc = 0;
188
189 TRY_CATCH (except, RETURN_MASK_ERROR)
190 {
191 *expression = parse_exp_1 (stringptr, pc ,block, comma);
192 }
193
194 if (except.reason < 0)
195 return 0;
196 return 1;
197 }
198
199 int
gdb_evaluate_expression(struct expression * exp,struct value ** value)200 gdb_evaluate_expression (struct expression *exp, struct value **value)
201 {
202 volatile struct gdb_exception except;
203
204 TRY_CATCH (except, RETURN_MASK_ERROR)
205 {
206 *value = evaluate_expression(exp);
207 }
208
209 if (except.reason < 0)
210 return 0;
211 return 1;
212 }
213
214 /*
215 * Parse an expression and return its value. If 'quiet' is true, then
216 * any error messages from the parser are masked.
217 */
218 CORE_ADDR
kgdb_parse_1(const char * exp,int quiet)219 kgdb_parse_1(const char *exp, int quiet)
220 {
221 struct ui_file *old_stderr;
222 struct cleanup *old_chain;
223 struct expression *expr;
224 struct value *val;
225 const char *s;
226 CORE_ADDR n;
227
228 old_stderr = gdb_stderr;
229 if (quiet)
230 gdb_stderr = parse_gdberr;
231 n = 0;
232 s = xstrdup(exp);
233 old_chain = make_cleanup(xfree, (char*)s);
234 if (gdb_parse_exp_1(&s, NULL, 0, &expr) && *s == '\0') {
235 make_cleanup(free_current_contents, &expr);
236 if (gdb_evaluate_expression(expr, &val))
237 n = value_as_address(val);
238 }
239 do_cleanups(old_chain);
240 gdb_stderr = old_stderr;
241 return (n);
242 }
243
244 #define MSGBUF_SEQ_TO_POS(size, seq) ((seq) % (size))
245
246 void
kgdb_dmesg(void)247 kgdb_dmesg(void)
248 {
249 CORE_ADDR bufp;
250 int size, rseq, wseq;
251 char c;
252
253 /*
254 * Display the unread portion of the message buffer. This gives the
255 * user a some initial data to work from.
256 */
257 if (quiet)
258 return;
259 bufp = kgdb_parse("msgbufp->msg_ptr");
260 size = (int)kgdb_parse("msgbufp->msg_size");
261 if (bufp == 0 || size == 0)
262 return;
263 rseq = (int)kgdb_parse("msgbufp->msg_bufr");
264 wseq = (int)kgdb_parse("msgbufp->msg_bufx");
265 rseq = MSGBUF_SEQ_TO_POS(size, rseq);
266 wseq = MSGBUF_SEQ_TO_POS(size, wseq);
267 if (rseq == wseq)
268 return;
269
270 printf("\nUnread portion of the kernel message buffer:\n");
271 while (rseq < wseq) {
272 read_memory(bufp + rseq, &c, 1);
273 putchar(c);
274 rseq++;
275 if (rseq == size)
276 rseq = 0;
277 }
278 if (c != '\n')
279 putchar('\n');
280 putchar('\n');
281 }
282
283 static void
kgdb_init(char * argv0 __unused)284 kgdb_init(char *argv0 __unused)
285 {
286
287 parse_gdberr = mem_fileopen();
288 set_prompt("(kgdb) ");
289 initialize_kgdb_target();
290 initialize_kld_target();
291 observer_attach_new_objfile(kgdb_new_objfile);
292 }
293
294 /*
295 * Remote targets can support any number of syntaxes and we want to
296 * support them all with one addition: we support specifying a device
297 * node for a serial device without the "/dev/" prefix.
298 *
299 * What we do is to stat(2) the existing remote target first. If that
300 * fails, we try it with "/dev/" prepended. If that succeeds we use
301 * the resulting path, otherwise we use the original target. If
302 * either stat(2) succeeds make sure the file is either a character
303 * device or a FIFO.
304 */
305 static void
verify_remote(void)306 verify_remote(void)
307 {
308 char path[PATH_MAX];
309 struct stat st;
310
311 if (stat(remote, &st) != 0) {
312 snprintf(path, sizeof(path), "/dev/%s", remote);
313 if (stat(path, &st) != 0)
314 return;
315 free(remote);
316 remote = strdup(path);
317 }
318 if (!S_ISCHR(st.st_mode) && !S_ISFIFO(st.st_mode))
319 errx(1, "%s: not a special file, FIFO or socket", remote);
320 }
321
322 static void
add_arg(struct captured_main_args * args,char * arg)323 add_arg(struct captured_main_args *args, char *arg)
324 {
325
326 args->argc++;
327 args->argv = reallocf(args->argv, (args->argc + 1) * sizeof(char *));
328 if (args->argv == NULL)
329 err(1, "Out of memory building argument list");
330 args->argv[args->argc] = arg;
331 }
332
333 int
main(int argc,char * argv[])334 main(int argc, char *argv[])
335 {
336 char path[PATH_MAX];
337 struct stat st;
338 struct captured_main_args args;
339 char *s;
340 int a, ch;
341
342 dumpnr = -1;
343
344 strlcpy(crashdir, "/var/crash", sizeof(crashdir));
345 s = getenv("KGDB_CRASH_DIR");
346 if (s != NULL)
347 strlcpy(crashdir, s, sizeof(crashdir));
348
349 /* Convert long options into short options. */
350 for (a = 1; a < argc; a++) {
351 s = argv[a];
352 if (s[0] == '-') {
353 s++;
354 /* Long options take either 1 or 2 dashes. */
355 if (s[0] == '-')
356 s++;
357 if (strcmp(s, "quiet") == 0)
358 argv[a] = "-q";
359 else if (strcmp(s, "fullname") == 0)
360 argv[a] = "-f";
361 else if (strcmp(s, "tui-mode") == 0)
362 argv[a] = "-t";
363 }
364 }
365
366 quiet = 0;
367 memset (&args, 0, sizeof args);
368 args.use_windows = 0;
369 args.interpreter_p = INTERP_CONSOLE;
370 args.argv = malloc(sizeof(char *));
371 args.argv[0] = argv[0];
372 add_arg(&args, "--kernel");
373
374 while ((ch = getopt(argc, argv, "ac:d:fn:qr:tvw")) != -1) {
375 switch (ch) {
376 case 'a':
377 annotation_level++;
378 break;
379 case 'c': /* use given core file. */
380 if (vmcore != NULL) {
381 warnx("option %c: can only be specified once",
382 optopt);
383 usage();
384 /* NOTREACHED */
385 }
386 vmcore = strdup(optarg);
387 break;
388 case 'd': /* lookup dumps in given directory. */
389 strlcpy(crashdir, optarg, sizeof(crashdir));
390 break;
391 case 'f':
392 annotation_level = 1;
393 break;
394 case 'n': /* use dump with given number. */
395 dumpnr = strtol(optarg, &s, 0);
396 if (dumpnr < 0 || *s != '\0') {
397 warnx("option %c: invalid kernel dump number",
398 optopt);
399 usage();
400 /* NOTREACHED */
401 }
402 break;
403 case 'q':
404 quiet = 1;
405 add_arg(&args, "-q");
406 break;
407 case 'r': /* use given device for remote session. */
408 if (remote != NULL) {
409 warnx("option %c: can only be specified once",
410 optopt);
411 usage();
412 /* NOTREACHED */
413 }
414 remote = strdup(optarg);
415 break;
416 case 't':
417 args.interpreter_p = INTERP_TUI;
418 add_arg(&args, "-tui");
419 quiet = 1;
420 add_arg(&args, "-q");
421 break;
422 case 'v': /* increase verbosity. */
423 verbose++;
424 break;
425 case 'w': /* core file is writeable. */
426 add_arg(&args, "--write");
427 break;
428 case '?':
429 default:
430 usage();
431 }
432 }
433
434 if (((vmcore != NULL) ? 1 : 0) + ((dumpnr >= 0) ? 1 : 0) +
435 ((remote != NULL) ? 1 : 0) > 1) {
436 warnx("options -c, -n and -r are mutually exclusive");
437 usage();
438 /* NOTREACHED */
439 }
440
441 if (verbose > 1)
442 warnx("using %s as the crash directory", crashdir);
443
444 if (argc > optind)
445 kernel = strdup(argv[optind++]);
446
447 if (argc > optind && (dumpnr >= 0 || remote != NULL)) {
448 warnx("options -n and -r do not take a core file. Ignored");
449 optind = argc;
450 }
451
452 if (dumpnr >= 0) {
453 snprintf(path, sizeof(path), "%s/vmcore.%d", crashdir, dumpnr);
454 if (stat(path, &st) == -1)
455 err(1, "%s", path);
456 if (!S_ISREG(st.st_mode))
457 errx(1, "%s: not a regular file", path);
458 vmcore = strdup(path);
459 } else if (remote != NULL) {
460 verify_remote();
461 } else if (argc > optind) {
462 if (vmcore == NULL)
463 vmcore = strdup(argv[optind++]);
464 if (argc > optind)
465 warnx("multiple core files specified. Ignored");
466 } else if (vmcore == NULL && kernel == NULL) {
467 vmcore = strdup(_PATH_MEM);
468 kernel = strdup(getbootfile());
469 }
470
471 if (verbose) {
472 if (vmcore != NULL)
473 warnx("core file: %s", vmcore);
474 if (remote != NULL)
475 warnx("device file: %s", remote);
476 if (kernel != NULL)
477 warnx("kernel image: %s", kernel);
478 }
479
480 /* A remote target requires an explicit kernel argument. */
481 if (remote != NULL && kernel == NULL) {
482 warnx("remote debugging requires a kernel");
483 usage();
484 /* NOTREACHED */
485 }
486
487 /* If we don't have a kernel image yet, try to find one. */
488 if (kernel == NULL) {
489 if (dumpnr >= 0)
490 kernel_from_dumpnr(dumpnr);
491
492 if (kernel == NULL)
493 errx(1, "couldn't find a suitable kernel image");
494 if (verbose)
495 warnx("kernel image: %s", kernel);
496 }
497 add_arg(&args, kernel);
498
499 /*
500 if (vmcore != NULL)
501 add_arg(&args, vmcore);
502 */
503
504 /* The libgdb code uses optind too. Reset it... */
505 optind = 0;
506
507 /* Terminate argv list. */
508 add_arg(&args, NULL);
509
510 deprecated_init_ui_hook = kgdb_init;
511
512 return (gdb_main(&args));
513 }
514