xref: /netbsd-src/usr.sbin/crash/crash.c (revision 946379e7b37692fc43f68eb0d1c10daa0a7f3b6c) 
1 /*	$NetBSD: crash.c,v 1.10 2015/06/16 23:48:20 christos Exp $	*/
2 
3 /*-
4  * Copyright (c) 2009 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Andrew Doran.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #ifndef lint
34 __RCSID("$NetBSD: crash.c,v 1.10 2015/06/16 23:48:20 christos Exp $");
35 #endif /* not lint */
36 
37 #include <ddb/ddb.h>
38 
39 #include <sys/fcntl.h>
40 #include <sys/mman.h>
41 #include <sys/ioctl.h>
42 
43 #include <machine/frame.h>
44 
45 #include <stdarg.h>
46 #include <stdlib.h>
47 #include <unistd.h>
48 #include <getopt.h>
49 #include <errno.h>
50 #include <histedit.h>
51 #include <paths.h>
52 #include <kvm.h>
53 #include <err.h>
54 #include <ctype.h>
55 #include <util.h>
56 
57 #include "extern.h"
58 
59 #define	MAXSTAB	(16 * 1024 * 1024)
60 
61 db_regs_t	ddb_regs;
62 
63 static kvm_t		*kd;
64 static History		*hist;
65 static HistEvent	he;
66 static EditLine		*elptr;
67 static char		imgrelease[16];
68 static FILE		*ofp;
69 
70 static struct nlist nl[] = {
71 #define	X_OSRELEASE	0
72 	{ .n_name = "_osrelease" },
73 #define	X_PANICSTR	1
74 	{ .n_name = "_panicstr" },
75 	{ .n_name = NULL },
76 };
77 
78 static void
79 cleanup(void)
80 {
81 	if (ofp != stdout) {
82 		(void)fflush(ofp);
83 		(void)pclose(ofp);
84 		ofp = stdout;
85 	}
86 	el_end(elptr);
87 	history_end(hist);
88 }
89 
90 void
91 db_vprintf(const char *fmt, va_list ap)
92 {
93 	char buf[1024];
94 	int b, c;
95 
96 	c = vsnprintf(buf, sizeof(buf), fmt, ap);
97 	for (b = 0; b < c; b++) {
98 		db_putchar(buf[b]);
99 	}
100 }
101 
102 void
103 db_printf(const char *fmt, ...)
104 {
105 	va_list ap;
106 
107 	va_start(ap, fmt);
108 	db_vprintf(fmt, ap);
109 	va_end(ap);
110 }
111 
112 void
113 db_write_bytes(db_addr_t addr, size_t size, const char *str)
114 {
115 
116 	if ((size_t)kvm_write(kd, addr, str, size) != size) {
117 		warnx("kvm_write(%p, %zd): %s", (void *)addr, size,
118 		    kvm_geterr(kd));
119 		longjmp(db_recover);
120 	}
121 }
122 
123 void
124 db_read_bytes(db_addr_t addr, size_t size, char *str)
125 {
126 
127 	if ((size_t)kvm_read(kd, addr, str, size) != size) {
128 		warnx("kvm_read(%p, %zd): %s", (void *)addr, size,
129 		    kvm_geterr(kd));
130 		longjmp(db_recover);
131 	}
132 }
133 
134 void *
135 db_alloc(size_t sz)
136 {
137 
138 	return emalloc(sz);
139 }
140 
141 void *
142 db_zalloc(size_t sz)
143 {
144 
145 	return ecalloc(1, sz);
146 }
147 
148 void
149 db_free(void *p, size_t sz)
150 {
151 
152 	free(p);
153 }
154 
155 static void
156 punt(void)
157 {
158 
159 	db_printf("This command can only be used in-kernel.\n");
160 }
161 
162 void
163 db_breakpoint_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
164     const char *modif)
165 {
166 
167 	punt();
168 }
169 
170 void
171 db_continue_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
172     const char *modif)
173 {
174 
175 	db_cmd_loop_done = true;
176 }
177 
178 void
179 db_delete_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
180     const char *modif)
181 {
182 
183 	punt();
184 }
185 
186 void
187 db_deletewatch_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
188     const char *modif)
189 {
190 
191 	punt();
192 }
193 
194 
195 void
196 db_trace_until_matching_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
197     const char *modif)
198 {
199 
200 	punt();
201 }
202 
203 
204 void
205 db_single_step_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
206     const char *modif)
207 {
208 
209 	punt();
210 }
211 
212 
213 void
214 db_trace_until_call_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
215     const char *modif)
216 {
217 
218 	punt();
219 }
220 
221 
222 void
223 db_watchpoint_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
224     const char *modif)
225 {
226 
227 	punt();
228 }
229 
230 int
231 db_readline(char *lstart, int lsize)
232 {
233 	const char *el;
234 	char *pcmd;
235 	int cnt;
236 
237 	db_force_whitespace();
238 
239 	/* Close any open pipe. */
240 	if (ofp != stdout) {
241 		(void)fflush(ofp);
242 		(void)pclose(ofp);
243 		ofp = stdout;
244 	}
245 
246 	/* Read next command. */
247 	el = el_gets(elptr, &cnt);
248 	if (el == NULL) {	/* EOF */
249 		exit(EXIT_SUCCESS);
250 	}
251 
252 	/* Save to history, and copy to caller's buffer. */
253 	history(hist, &he, H_ENTER, el);
254 	strlcpy(lstart, el, lsize);
255 	if (cnt >= lsize) {
256 		cnt = lsize - 1;
257 	}
258 	lstart[cnt] = '\0';
259 	if (cnt > 0 && lstart[cnt - 1] == '\n') {
260 		lstart[cnt - 1] = '\0';
261 	}
262 
263 	/* Need to open a pipe? If not, return now. */
264 	pcmd = strchr(lstart, '|');
265 	if (pcmd == NULL) {
266 		return strlen(lstart);
267 	}
268 
269 	/* Open a pipe to specified command, redirect output. */
270 	assert(ofp == stdout);
271 	for (*pcmd++ = '\0'; isspace((unsigned char)*pcmd); pcmd++) {
272 		/* nothing */
273 	}
274 	errno = 0;
275 	ofp = popen(pcmd, "w");
276 	if (ofp == NULL) {
277 		warn("opening pipe for command `%s'", pcmd);
278 		*lstart = '\0';
279 	}
280 	return strlen(lstart);
281 }
282 
283 void
284 db_check_interrupt(void)
285 {
286 
287 }
288 
289 int
290 cngetc(void)
291 {
292 
293 	fprintf(stderr, "cngetc\n");
294 	abort();
295 }
296 
297 void
298 cnputc(int c)
299 {
300 
301 	putc(c, ofp);
302 }
303 
304 __dead static void
305 usage(void)
306 {
307 
308 	fprintf(stderr,
309 	    "usage: %s [-w] [-M core] [-N kernel]\n\n"
310 	    "-M core\tspecify memory file (default /dev/mem)\n"
311 	    "-N kernel\tspecify name list file (default /dev/ksyms)\n",
312 	    getprogname());
313 	exit(EXIT_FAILURE);
314 }
315 
316 static const char *
317 prompt(void)
318 {
319 
320 	return "crash> ";
321 }
322 
323 int
324 main(int argc, char **argv)
325 {
326 	const char *nlistf, *memf;
327 	uintptr_t panicstr;
328 	struct winsize ws;
329 	struct stat sb;
330 	size_t sz;
331 	void *elf;
332 	int fd, ch, flags;
333 	char c;
334 
335 	nlistf = _PATH_KSYMS;
336 	memf = _PATH_MEM;
337 	ofp = stdout;
338 	flags = O_RDONLY;
339 
340 	setprogname(argv[0]);
341 
342 	/*
343 	 * Parse options.
344 	 */
345 	while ((ch = getopt(argc, argv, "M:N:w")) != -1) {
346 		switch (ch) {
347 		case 'M':
348 			memf = optarg;
349 			break;
350 		case 'N':
351 			nlistf = optarg;
352 			break;
353 		case 'w':
354 			flags = O_RDWR;
355 			break;
356 		default:
357 			usage();
358 		}
359 	}
360 	argc -= optind;
361 	argv += optind;
362 
363 	/*
364 	 * Print a list of images, and allow user to select.
365 	 */
366 	/* XXX */
367 
368 	/*
369 	 * Open the images (crash dump and symbol table).
370 	 */
371 	kd = kvm_open(nlistf, memf, NULL, flags, getprogname());
372 	if (kd == NULL) {
373 		return EXIT_FAILURE;
374 	}
375 	fd = open(nlistf, O_RDONLY);
376 	if (fd == -1)  {
377 		err(EXIT_FAILURE, "open `%s'", nlistf);
378 	}
379 	if (fstat(fd, &sb) == -1) {
380 		err(EXIT_FAILURE, "stat `%s'", nlistf);
381 	}
382 	if ((sb.st_mode & S_IFMT) != S_IFREG) {	/* XXX ksyms */
383 		sz = MAXSTAB;
384 		elf = malloc(sz);
385 		if (elf == NULL) {
386 			err(EXIT_FAILURE, "malloc(%zu)", sz);
387 		}
388 		sz = read(fd, elf, sz);
389 		if ((ssize_t)sz == -1) {
390 			err(EXIT_FAILURE, "read `%s'", nlistf);
391 		}
392 		if (sz == MAXSTAB) {
393 			errx(EXIT_FAILURE, "symbol table > %d bytes", MAXSTAB);
394 		}
395 	} else {
396 		sz = sb.st_size;
397 		elf = mmap(NULL, sz, PROT_READ, MAP_PRIVATE|MAP_FILE, fd, 0);
398 		if (elf == MAP_FAILED) {
399 			err(EXIT_FAILURE, "mmap `%s'", nlistf);
400 		}
401 	}
402 
403 	/*
404 	 * Print kernel & crash versions.
405 	 */
406 	if (kvm_nlist(kd, nl) == -1) {
407 		errx(EXIT_FAILURE, "kvm_nlist: %s", kvm_geterr(kd));
408 	}
409 	if ((size_t)kvm_read(kd, nl[X_OSRELEASE].n_value, imgrelease,
410 	    sizeof(imgrelease)) != sizeof(imgrelease)) {
411 		errx(EXIT_FAILURE, "cannot read osrelease: %s",
412 		    kvm_geterr(kd));
413 	}
414 	printf("Crash version %s, image version %s.\n", osrelease, imgrelease);
415 	if (strcmp(osrelease, imgrelease) != 0) {
416 		printf("WARNING: versions differ, you may not be able to "
417 		    "examine this image.\n");
418 	}
419 
420 	/*
421 	 * Print the panic string, if any.
422 	 */
423 	if ((size_t)kvm_read(kd, nl[X_PANICSTR].n_value, &panicstr,
424 	    sizeof(panicstr)) != sizeof(panicstr)) {
425 		errx(EXIT_FAILURE, "cannot read panicstr: %s",
426 		    kvm_geterr(kd));
427 	}
428 	if (strcmp(memf, _PATH_MEM) == 0) {
429 		printf("Output from a running system is unreliable.\n");
430 	} else if (panicstr == 0) {
431 		printf("System does not appear to have panicked.\n");
432 	} else {
433 		printf("System panicked: ");
434 		for (;;) {
435 			if ((size_t)kvm_read(kd, panicstr, &c, sizeof(c)) !=
436 			    sizeof(c)) {
437 				errx(EXIT_FAILURE, "cannot read *panicstr: %s",
438 				    kvm_geterr(kd));
439 			}
440 			if (c == '\0') {
441 				break;
442 			}
443 			putchar(c);
444 			panicstr++;
445 		}
446 		putchar('\n');
447 	}
448 
449 	/*
450 	 * Initialize line editing.
451 	 */
452 	hist = history_init();
453 	history(hist, &he, H_SETSIZE, 100);
454 	elptr = el_init(getprogname(), stdin, stdout, stderr);
455 	el_set(elptr, EL_EDITOR, "emacs");
456 	el_set(elptr, EL_SIGNAL, 1);
457 	el_set(elptr, EL_HIST, history, hist);
458 	el_set(elptr, EL_PROMPT, prompt);
459 	el_source(elptr, NULL);
460 
461 	atexit(cleanup);
462 
463 	/*
464 	 * Initialize ddb.
465 	 */
466 	if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) != -1) {
467 		db_max_width = ws.ws_col;
468 	}
469 	db_mach_init(kd);
470 	ddb_init(sz, elf, (char *)elf + sz);
471 
472 	/*
473 	 * Debug it!
474 	 */
475 	db_command_loop();
476 
477 	/*
478 	 * Finish.
479 	 */
480 	return EXIT_SUCCESS;
481 }
482