xref: /netbsd-src/usr.sbin/crash/crash.c (revision e6c7e151de239c49d2e38720a061ed9d1fa99309) 
1 /*	$NetBSD: crash.c,v 1.13 2020/03/27 00:17:08 ad 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 1.13 2020/03/27 00:17:08 ad 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/stat.h>
42 #include <sys/ioctl.h>
43 
44 #include <machine/frame.h>
45 
46 #include <stdarg.h>
47 #include <stdlib.h>
48 #include <unistd.h>
49 #include <getopt.h>
50 #include <errno.h>
51 #include <histedit.h>
52 #include <paths.h>
53 #include <kvm.h>
54 #include <err.h>
55 #include <ctype.h>
56 #include <util.h>
57 
58 #include "extern.h"
59 
60 #define	MAXSTAB	(16 * 1024 * 1024)
61 
62 db_regs_t	ddb_regs;
63 
64 static kvm_t		*kd;
65 static History		*hist;
66 static HistEvent	he;
67 static EditLine		*elptr;
68 static char		imgrelease[16];
69 static FILE		*ofp;
70 
71 static struct nlist nl[] = {
72 #define	X_OSRELEASE	0
73 	{ .n_name = "_osrelease" },
74 #define	X_PANICSTR	1
75 	{ .n_name = "_panicstr" },
76 #ifdef LOCKDEBUG
77 #define	X_LOCKDEBUG	2
78 	{ .n_name = "ld_all" },
79 #endif
80 	{ .n_name = NULL },
81 };
82 
83 #ifdef LOCKDEBUG
84 struct lockdebug;
85 TAILQ_HEAD(, lockdebug) ld_all;
86 #else
87 void lockdebug_lock_print(void);
88 void lockdebug_lock_print(void) {
89 	warnx("No lockdebug support compiled in");
90 }
91 #endif
92 
93 
94 static void
95 cleanup(void)
96 {
97 	if (ofp != stdout) {
98 		(void)fflush(ofp);
99 		(void)pclose(ofp);
100 		ofp = stdout;
101 	}
102 	el_end(elptr);
103 	history_end(hist);
104 }
105 
106 void
107 db_vprintf(const char *fmt, va_list ap)
108 {
109 	char buf[1024];
110 	int b, c;
111 
112 	c = vsnprintf(buf, sizeof(buf), fmt, ap);
113 	for (b = 0; b < c; b++) {
114 		db_putchar(buf[b]);
115 	}
116 }
117 
118 void
119 db_printf(const char *fmt, ...)
120 {
121 	va_list ap;
122 
123 	va_start(ap, fmt);
124 	db_vprintf(fmt, ap);
125 	va_end(ap);
126 }
127 
128 void
129 db_write_bytes(db_addr_t addr, size_t size, const char *str)
130 {
131 
132 	if ((size_t)kvm_write(kd, addr, str, size) != size) {
133 		warnx("kvm_write(%p, %zd): %s", (void *)addr, size,
134 		    kvm_geterr(kd));
135 		longjmp(db_recover);
136 	}
137 }
138 
139 void
140 db_read_bytes(db_addr_t addr, size_t size, char *str)
141 {
142 
143 	if ((size_t)kvm_read(kd, addr, str, size) != size) {
144 		warnx("kvm_read(%p, %zd): %s", (void *)addr, size,
145 		    kvm_geterr(kd));
146 		longjmp(db_recover);
147 	}
148 }
149 
150 void *
151 db_alloc(size_t sz)
152 {
153 
154 	return emalloc(sz);
155 }
156 
157 void *
158 db_zalloc(size_t sz)
159 {
160 
161 	return ecalloc(1, sz);
162 }
163 
164 void
165 db_free(void *p, size_t sz)
166 {
167 
168 	free(p);
169 }
170 
171 static void
172 punt(void)
173 {
174 
175 	db_printf("This command can only be used in-kernel.\n");
176 }
177 
178 void
179 db_breakpoint_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_continue_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
188     const char *modif)
189 {
190 
191 	db_cmd_loop_done = true;
192 }
193 
194 void
195 db_delete_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
196     const char *modif)
197 {
198 
199 	punt();
200 }
201 
202 void
203 db_deletewatch_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
204     const char *modif)
205 {
206 
207 	punt();
208 }
209 
210 
211 void
212 db_trace_until_matching_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
213     const char *modif)
214 {
215 
216 	punt();
217 }
218 
219 
220 void
221 db_single_step_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
222     const char *modif)
223 {
224 
225 	punt();
226 }
227 
228 
229 void
230 db_trace_until_call_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
231     const char *modif)
232 {
233 
234 	punt();
235 }
236 
237 
238 void
239 db_watchpoint_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
240     const char *modif)
241 {
242 
243 	punt();
244 }
245 
246 int
247 db_readline(char *lstart, int lsize)
248 {
249 	const char *el;
250 	char *pcmd;
251 	int cnt;
252 
253 	db_force_whitespace();
254 
255 	/* Close any open pipe. */
256 	if (ofp != stdout) {
257 		(void)fflush(ofp);
258 		(void)pclose(ofp);
259 		ofp = stdout;
260 	}
261 
262 	/* Read next command. */
263 	el = el_gets(elptr, &cnt);
264 	if (el == NULL) {	/* EOF */
265 		exit(EXIT_SUCCESS);
266 	}
267 
268 	/* Save to history, and copy to caller's buffer. */
269 	history(hist, &he, H_ENTER, el);
270 	strlcpy(lstart, el, lsize);
271 	if (cnt >= lsize) {
272 		cnt = lsize - 1;
273 	}
274 	lstart[cnt] = '\0';
275 	if (cnt > 0 && lstart[cnt - 1] == '\n') {
276 		lstart[cnt - 1] = '\0';
277 	}
278 
279 	/* Need to open a pipe? If not, return now. */
280 	pcmd = strchr(lstart, '|');
281 	if (pcmd == NULL) {
282 		return strlen(lstart);
283 	}
284 
285 	/* Open a pipe to specified command, redirect output. */
286 	assert(ofp == stdout);
287 	for (*pcmd++ = '\0'; isspace((unsigned char)*pcmd); pcmd++) {
288 		/* nothing */
289 	}
290 	errno = 0;
291 	ofp = popen(pcmd, "w");
292 	if (ofp == NULL) {
293 		warn("opening pipe for command `%s'", pcmd);
294 		*lstart = '\0';
295 	}
296 	return strlen(lstart);
297 }
298 
299 void
300 db_check_interrupt(void)
301 {
302 
303 }
304 
305 int
306 cngetc(void)
307 {
308 
309 	fprintf(stderr, "cngetc\n");
310 	abort();
311 }
312 
313 void
314 cnputc(int c)
315 {
316 
317 	putc(c, ofp);
318 }
319 
320 __dead static void
321 usage(void)
322 {
323 
324 	fprintf(stderr,
325 	    "usage: %s [-w] [-M core] [-N kernel]\n\n"
326 	    "-M core\tspecify memory file (default /dev/mem)\n"
327 	    "-N kernel\tspecify name list file (default /dev/ksyms)\n",
328 	    getprogname());
329 	exit(EXIT_FAILURE);
330 }
331 
332 static const char *
333 prompt(void)
334 {
335 
336 	return "crash> ";
337 }
338 
339 int
340 main(int argc, char **argv)
341 {
342 	const char *nlistf, *memf;
343 	uintptr_t panicstr;
344 	struct winsize ws;
345 	struct stat sb;
346 	size_t sz;
347 	void *elf;
348 	int fd, ch, flags;
349 	char c;
350 
351 	nlistf = _PATH_KSYMS;
352 	memf = _PATH_MEM;
353 	ofp = stdout;
354 	flags = O_RDONLY;
355 
356 	setprogname(argv[0]);
357 
358 	/*
359 	 * Parse options.
360 	 */
361 	while ((ch = getopt(argc, argv, "M:N:w")) != -1) {
362 		switch (ch) {
363 		case 'M':
364 			memf = optarg;
365 			break;
366 		case 'N':
367 			nlistf = optarg;
368 			break;
369 		case 'w':
370 			flags = O_RDWR;
371 			break;
372 		default:
373 			usage();
374 		}
375 	}
376 	argc -= optind;
377 	argv += optind;
378 
379 	/*
380 	 * Print a list of images, and allow user to select.
381 	 */
382 	/* XXX */
383 
384 	/*
385 	 * Open the images (crash dump and symbol table).
386 	 */
387 	kd = kvm_open(nlistf, memf, NULL, flags, getprogname());
388 	if (kd == NULL) {
389 		return EXIT_FAILURE;
390 	}
391 	fd = open(nlistf, O_RDONLY);
392 	if (fd == -1)  {
393 		err(EXIT_FAILURE, "open `%s'", nlistf);
394 	}
395 	if (fstat(fd, &sb) == -1) {
396 		err(EXIT_FAILURE, "stat `%s'", nlistf);
397 	}
398 	if ((sb.st_mode & S_IFMT) != S_IFREG) {	/* XXX ksyms */
399 		sz = MAXSTAB;
400 		elf = malloc(sz);
401 		if (elf == NULL) {
402 			err(EXIT_FAILURE, "malloc(%zu)", sz);
403 		}
404 		sz = read(fd, elf, sz);
405 		if ((ssize_t)sz == -1) {
406 			err(EXIT_FAILURE, "read `%s'", nlistf);
407 		}
408 		if (sz == MAXSTAB) {
409 			errx(EXIT_FAILURE, "symbol table > %d bytes", MAXSTAB);
410 		}
411 	} else {
412 		sz = sb.st_size;
413 		elf = mmap(NULL, sz, PROT_READ, MAP_PRIVATE|MAP_FILE, fd, 0);
414 		if (elf == MAP_FAILED) {
415 			err(EXIT_FAILURE, "mmap `%s'", nlistf);
416 		}
417 	}
418 
419 	/*
420 	 * Print kernel & crash versions.
421 	 */
422 	if (kvm_nlist(kd, nl) == -1) {
423 		errx(EXIT_FAILURE, "kvm_nlist: %s", kvm_geterr(kd));
424 	}
425 	if ((size_t)kvm_read(kd, nl[X_OSRELEASE].n_value, imgrelease,
426 	    sizeof(imgrelease)) != sizeof(imgrelease)) {
427 		errx(EXIT_FAILURE, "cannot read osrelease: %s",
428 		    kvm_geterr(kd));
429 	}
430 	printf("Crash version %s, image version %s.\n", osrelease, imgrelease);
431 	if (strcmp(osrelease, imgrelease) != 0) {
432 		printf("WARNING: versions differ, you may not be able to "
433 		    "examine this image.\n");
434 	}
435 #ifdef LOCKDEBUG
436 	if ((size_t)kvm_read(kd, nl[X_LOCKDEBUG].n_value, &ld_all,
437 	    sizeof(ld_all)) != sizeof(ld_all))
438 		printf("Kernel compiled without options LOCKDEBUG.\n");
439 #endif
440 
441 	/*
442 	 * Print the panic string, if any.
443 	 */
444 	if ((size_t)kvm_read(kd, nl[X_PANICSTR].n_value, &panicstr,
445 	    sizeof(panicstr)) != sizeof(panicstr)) {
446 		errx(EXIT_FAILURE, "cannot read panicstr: %s",
447 		    kvm_geterr(kd));
448 	}
449 	if (strcmp(memf, _PATH_MEM) == 0) {
450 		printf("Output from a running system is unreliable.\n");
451 	} else if (panicstr == 0) {
452 		printf("System does not appear to have panicked.\n");
453 	} else {
454 		printf("System panicked: ");
455 		for (;;) {
456 			if ((size_t)kvm_read(kd, panicstr, &c, sizeof(c)) !=
457 			    sizeof(c)) {
458 				errx(EXIT_FAILURE, "cannot read *panicstr: %s",
459 				    kvm_geterr(kd));
460 			}
461 			if (c == '\0') {
462 				break;
463 			}
464 			putchar(c);
465 			panicstr++;
466 		}
467 		putchar('\n');
468 	}
469 
470 	/*
471 	 * Initialize line editing.
472 	 */
473 	hist = history_init();
474 	history(hist, &he, H_SETSIZE, 100);
475 	elptr = el_init(getprogname(), stdin, stdout, stderr);
476 	el_set(elptr, EL_EDITOR, "emacs");
477 	el_set(elptr, EL_SIGNAL, 1);
478 	el_set(elptr, EL_HIST, history, hist);
479 	el_set(elptr, EL_PROMPT, prompt);
480 	el_source(elptr, NULL);
481 
482 	atexit(cleanup);
483 
484 	/*
485 	 * Initialize ddb.
486 	 */
487 	if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) != -1) {
488 		db_max_width = ws.ws_col;
489 	}
490 	db_mach_init(kd);
491 	ddb_init(sz, elf, (char *)elf + sz);
492 
493 	/*
494 	 * Debug it!
495 	 */
496 	db_command_loop();
497 
498 	/*
499 	 * Finish.
500 	 */
501 	return EXIT_SUCCESS;
502 }
503