xref: /netbsd-src/usr.sbin/crash/crash.c (revision 4724848cf0da353df257f730694b7882798e5daf) 
1 /*	$NetBSD: crash.c,v 1.15 2023/04/12 17:53:32 riastradh 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 1.15 2023/04/12 17:53:32 riastradh Exp $");
35 #endif /* not lint */
36 
37 #include <sys/types.h>
38 
39 #include <sys/fcntl.h>
40 #include <sys/mman.h>
41 #include <sys/stat.h>
42 #include <sys/ioctl.h>
43 
44 #ifndef __mips__
45 #include <machine/frame.h>
46 #endif
47 
48 #include <ddb/ddb.h>
49 
50 #include <stdarg.h>
51 #include <stdlib.h>
52 #include <unistd.h>
53 #include <getopt.h>
54 #include <errno.h>
55 #include <histedit.h>
56 #include <paths.h>
57 #include <kvm.h>
58 #include <err.h>
59 #include <ctype.h>
60 #include <util.h>
61 
62 #include "extern.h"
63 
64 #define	MAXSTAB	(16 * 1024 * 1024)
65 
66 db_regs_t	ddb_regs;
67 
68 static kvm_t		*kd;
69 static History		*hist;
70 static HistEvent	he;
71 static EditLine		*elptr;
72 static char		imgrelease[16];
73 static FILE		*ofp;
74 
75 static struct nlist nl[] = {
76 #define	X_OSRELEASE	0
77 	{ .n_name = "_osrelease" },
78 #define	X_PANICSTR	1
79 	{ .n_name = "_panicstr" },
80 #ifdef LOCKDEBUG
81 #define	X_LOCKDEBUG	2
82 	{ .n_name = "ld_all" },
83 #endif
84 	{ .n_name = NULL },
85 };
86 
87 #ifdef LOCKDEBUG
88 struct lockdebug;
89 TAILQ_HEAD(, lockdebug) ld_all;
90 #else
91 void lockdebug_lock_print(void);
92 void lockdebug_lock_print(void) {
93 	warnx("No lockdebug support compiled in");
94 }
95 #endif
96 
97 
98 static void
99 cleanup(void)
100 {
101 	if (ofp != stdout) {
102 		(void)fflush(ofp);
103 		(void)pclose(ofp);
104 		ofp = stdout;
105 	}
106 	el_end(elptr);
107 	history_end(hist);
108 }
109 
110 void
111 db_vprintf(const char *fmt, va_list ap)
112 {
113 	char buf[1024];
114 	int b, c;
115 
116 	c = vsnprintf(buf, sizeof(buf), fmt, ap);
117 	for (b = 0; b < c; b++) {
118 		db_putchar(buf[b]);
119 	}
120 }
121 
122 void
123 db_printf(const char *fmt, ...)
124 {
125 	va_list ap;
126 
127 	va_start(ap, fmt);
128 	db_vprintf(fmt, ap);
129 	va_end(ap);
130 }
131 
132 void
133 db_write_bytes(db_addr_t addr, size_t size, const char *str)
134 {
135 
136 	if ((size_t)kvm_write(kd, addr, str, size) != size) {
137 		warnx("kvm_write(%p, %zd): %s", (void *)addr, size,
138 		    kvm_geterr(kd));
139 		longjmp(db_recover);
140 	}
141 }
142 
143 void
144 db_read_bytes(db_addr_t addr, size_t size, char *str)
145 {
146 
147 	if ((size_t)kvm_read(kd, addr, str, size) != size) {
148 		warnx("kvm_read(%p, %zd): %s", (void *)addr, size,
149 		    kvm_geterr(kd));
150 		longjmp(db_recover);
151 	}
152 }
153 
154 void *
155 db_alloc(size_t sz)
156 {
157 
158 	return emalloc(sz);
159 }
160 
161 void *
162 db_zalloc(size_t sz)
163 {
164 
165 	return ecalloc(1, sz);
166 }
167 
168 void
169 db_free(void *p, size_t sz)
170 {
171 
172 	free(p);
173 }
174 
175 static void
176 punt(void)
177 {
178 
179 	db_printf("This command can only be used in-kernel.\n");
180 }
181 
182 void
183 db_breakpoint_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
184     const char *modif)
185 {
186 
187 	punt();
188 }
189 
190 void
191 db_continue_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
192     const char *modif)
193 {
194 
195 	db_cmd_loop_done = true;
196 }
197 
198 void
199 db_delete_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
200     const char *modif)
201 {
202 
203 	punt();
204 }
205 
206 void
207 db_deletewatch_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
208     const char *modif)
209 {
210 
211 	punt();
212 }
213 
214 
215 void
216 db_trace_until_matching_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
217     const char *modif)
218 {
219 
220 	punt();
221 }
222 
223 
224 void
225 db_single_step_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
226     const char *modif)
227 {
228 
229 	punt();
230 }
231 
232 
233 void
234 db_trace_until_call_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
235     const char *modif)
236 {
237 
238 	punt();
239 }
240 
241 
242 void
243 db_watchpoint_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
244     const char *modif)
245 {
246 
247 	punt();
248 }
249 
250 int
251 db_readline(char *lstart, int lsize)
252 {
253 	const char *el;
254 	char *pcmd;
255 	int cnt;
256 
257 	db_force_whitespace();
258 
259 	/* Close any open pipe. */
260 	if (ofp != stdout) {
261 		(void)fflush(ofp);
262 		(void)pclose(ofp);
263 		ofp = stdout;
264 	}
265 
266 	/* Read next command. */
267 	el = el_gets(elptr, &cnt);
268 	if (el == NULL) {	/* EOF */
269 		exit(EXIT_SUCCESS);
270 	}
271 
272 	/* Save to history, and copy to caller's buffer. */
273 	history(hist, &he, H_ENTER, el);
274 	strlcpy(lstart, el, lsize);
275 	if (cnt >= lsize) {
276 		cnt = lsize - 1;
277 	}
278 	lstart[cnt] = '\0';
279 	if (cnt > 0 && lstart[cnt - 1] == '\n') {
280 		lstart[cnt - 1] = '\0';
281 	}
282 
283 	/* Need to open a pipe? If not, return now. */
284 	pcmd = strchr(lstart, '|');
285 	if (pcmd == NULL) {
286 		return strlen(lstart);
287 	}
288 
289 	/* Open a pipe to specified command, redirect output. */
290 	assert(ofp == stdout);
291 	for (*pcmd++ = '\0'; isspace((unsigned char)*pcmd); pcmd++) {
292 		/* nothing */
293 	}
294 	errno = 0;
295 	ofp = popen(pcmd, "w");
296 	if (ofp == NULL) {
297 		warn("opening pipe for command `%s'", pcmd);
298 		*lstart = '\0';
299 	}
300 	return strlen(lstart);
301 }
302 
303 void
304 db_check_interrupt(void)
305 {
306 
307 }
308 
309 int
310 cngetc(void)
311 {
312 
313 	fprintf(stderr, "cngetc\n");
314 	abort();
315 }
316 
317 void
318 cnputc(int c)
319 {
320 
321 	putc(c, ofp);
322 }
323 
324 __dead static void
325 usage(void)
326 {
327 
328 	fprintf(stderr,
329 	    "usage: %s [-w] [-M core] [-N kernel]\n\n"
330 	    "-M core\tspecify memory file (default /dev/mem)\n"
331 	    "-N kernel\tspecify name list file (default /dev/ksyms)\n",
332 	    getprogname());
333 	exit(EXIT_FAILURE);
334 }
335 
336 static const char *
337 prompt(void)
338 {
339 
340 	return "crash> ";
341 }
342 
343 int
344 main(int argc, char **argv)
345 {
346 	const char *nlistf, *memf;
347 	uintptr_t panicstr;
348 	struct winsize ws;
349 	struct stat sb;
350 	size_t sz;
351 	void *elf;
352 	int fd, ch, flags;
353 	char c;
354 
355 	nlistf = _PATH_KSYMS;
356 	memf = _PATH_MEM;
357 	ofp = stdout;
358 	flags = O_RDONLY;
359 
360 	setprogname(argv[0]);
361 
362 	/*
363 	 * Parse options.
364 	 */
365 	while ((ch = getopt(argc, argv, "M:N:w")) != -1) {
366 		switch (ch) {
367 		case 'M':
368 			memf = optarg;
369 			break;
370 		case 'N':
371 			nlistf = optarg;
372 			break;
373 		case 'w':
374 			flags = O_RDWR;
375 			break;
376 		default:
377 			usage();
378 		}
379 	}
380 	argc -= optind;
381 	argv += optind;
382 
383 	/*
384 	 * Print a list of images, and allow user to select.
385 	 */
386 	/* XXX */
387 
388 	/*
389 	 * Open the images (crash dump and symbol table).
390 	 */
391 	kd = kvm_open(nlistf, memf, NULL, flags, getprogname());
392 	if (kd == NULL) {
393 		return EXIT_FAILURE;
394 	}
395 	fd = open(nlistf, O_RDONLY);
396 	if (fd == -1)  {
397 		err(EXIT_FAILURE, "open `%s'", nlistf);
398 	}
399 	if (fstat(fd, &sb) == -1) {
400 		err(EXIT_FAILURE, "stat `%s'", nlistf);
401 	}
402 	if ((sb.st_mode & S_IFMT) != S_IFREG) {	/* XXX ksyms */
403 		sz = MAXSTAB;
404 		elf = malloc(sz);
405 		if (elf == NULL) {
406 			err(EXIT_FAILURE, "malloc(%zu)", sz);
407 		}
408 		sz = read(fd, elf, sz);
409 		if ((ssize_t)sz == -1) {
410 			err(EXIT_FAILURE, "read `%s'", nlistf);
411 		}
412 		if (sz == MAXSTAB) {
413 			errx(EXIT_FAILURE, "symbol table > %d bytes", MAXSTAB);
414 		}
415 	} else {
416 		sz = sb.st_size;
417 		elf = mmap(NULL, sz, PROT_READ, MAP_PRIVATE|MAP_FILE, fd, 0);
418 		if (elf == MAP_FAILED) {
419 			err(EXIT_FAILURE, "mmap `%s'", nlistf);
420 		}
421 	}
422 
423 	/*
424 	 * Print kernel & crash versions.
425 	 */
426 	if (kvm_nlist(kd, nl) == -1) {
427 		errx(EXIT_FAILURE, "kvm_nlist: %s", kvm_geterr(kd));
428 	}
429 	if ((size_t)kvm_read(kd, nl[X_OSRELEASE].n_value, imgrelease,
430 	    sizeof(imgrelease)) != sizeof(imgrelease)) {
431 		errx(EXIT_FAILURE, "cannot read osrelease: %s",
432 		    kvm_geterr(kd));
433 	}
434 	printf("Crash version %s, image version %s.\n", osrelease, imgrelease);
435 	if (strcmp(osrelease, imgrelease) != 0) {
436 		printf("WARNING: versions differ, you may not be able to "
437 		    "examine this image.\n");
438 	}
439 #ifdef LOCKDEBUG
440 	if ((size_t)kvm_read(kd, nl[X_LOCKDEBUG].n_value, &ld_all,
441 	    sizeof(ld_all)) != sizeof(ld_all))
442 		printf("Kernel compiled without options LOCKDEBUG.\n");
443 #endif
444 
445 	/*
446 	 * Print the panic string, if any.
447 	 */
448 	if ((size_t)kvm_read(kd, nl[X_PANICSTR].n_value, &panicstr,
449 	    sizeof(panicstr)) != sizeof(panicstr)) {
450 		errx(EXIT_FAILURE, "cannot read panicstr: %s",
451 		    kvm_geterr(kd));
452 	}
453 	if (strcmp(memf, _PATH_MEM) == 0) {
454 		printf("Output from a running system is unreliable.\n");
455 	} else if (panicstr == 0) {
456 		printf("System does not appear to have panicked.\n");
457 	} else {
458 		printf("System panicked: ");
459 		for (;;) {
460 			if ((size_t)kvm_read(kd, panicstr, &c, sizeof(c)) !=
461 			    sizeof(c)) {
462 				errx(EXIT_FAILURE, "cannot read *panicstr: %s",
463 				    kvm_geterr(kd));
464 			}
465 			if (c == '\0') {
466 				break;
467 			}
468 			putchar(c);
469 			panicstr++;
470 		}
471 		putchar('\n');
472 	}
473 
474 	/*
475 	 * Initialize line editing.
476 	 */
477 	hist = history_init();
478 	history(hist, &he, H_SETSIZE, 100);
479 	elptr = el_init(getprogname(), stdin, stdout, stderr);
480 	el_set(elptr, EL_EDITOR, "emacs");
481 	el_set(elptr, EL_SIGNAL, 1);
482 	el_set(elptr, EL_HIST, history, hist);
483 	el_set(elptr, EL_PROMPT, prompt);
484 	el_source(elptr, NULL);
485 
486 	atexit(cleanup);
487 
488 	/*
489 	 * Initialize ddb.
490 	 */
491 	if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) != -1) {
492 		db_max_width = ws.ws_col;
493 	}
494 	db_mach_init(kd);
495 	ddb_init(sz, elf, (char *)elf + sz);
496 
497 	/*
498 	 * Debug it!
499 	 */
500 	db_command_loop();
501 
502 	/*
503 	 * Finish.
504 	 */
505 	return EXIT_SUCCESS;
506 }
507