xref: /netbsd-src/sys/ddb/db_command.c (revision 001c68bd94f75ce9270b69227c4199fbf34ee396)
1 /*	$NetBSD: db_command.c,v 1.71 2003/05/16 16:28:30 itojun Exp $	*/
2 
3 /*
4  * Mach Operating System
5  * Copyright (c) 1991,1990 Carnegie Mellon University
6  * All Rights Reserved.
7  *
8  * Permission to use, copy, modify and distribute this software and its
9  * documentation is hereby granted, provided that both the copyright
10  * notice and this permission notice appear in all copies of the
11  * software, derivative works or modified versions, and any portions
12  * thereof, and that both notices appear in supporting documentation.
13  *
14  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
15  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
16  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
17  *
18  * Carnegie Mellon requests users of this software to return to
19  *
20  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
21  *  School of Computer Science
22  *  Carnegie Mellon University
23  *  Pittsburgh PA 15213-3890
24  *
25  * any improvements or extensions that they make and grant Carnegie the
26  * rights to redistribute these changes.
27  */
28 
29 /*
30  * Command dispatcher.
31  */
32 
33 #include <sys/cdefs.h>
34 __KERNEL_RCSID(0, "$NetBSD: db_command.c,v 1.71 2003/05/16 16:28:30 itojun Exp $");
35 
36 #include "opt_ddb.h"
37 #include "opt_kgdb.h"
38 #include "opt_inet.h"
39 
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/reboot.h>
43 #include <sys/device.h>
44 #include <sys/malloc.h>
45 #include <sys/namei.h>
46 #include <sys/pool.h>
47 #include <sys/proc.h>
48 #include <sys/vnode.h>
49 
50 #include <machine/db_machdep.h>		/* type definitions */
51 
52 #if defined(_KERNEL_OPT)
53 #include "opt_multiprocessor.h"
54 #endif
55 #ifdef MULTIPROCESSOR
56 #include <machine/cpu.h>
57 #endif
58 
59 #include <ddb/db_lex.h>
60 #include <ddb/db_output.h>
61 #include <ddb/db_command.h>
62 #include <ddb/db_break.h>
63 #include <ddb/db_watch.h>
64 #include <ddb/db_run.h>
65 #include <ddb/db_variables.h>
66 #include <ddb/db_interface.h>
67 #include <ddb/db_sym.h>
68 #include <ddb/db_extern.h>
69 
70 #include <uvm/uvm_extern.h>
71 #include <uvm/uvm_ddb.h>
72 
73 #include "arp.h"
74 
75 /*
76  * Results of command search.
77  */
78 #define	CMD_UNIQUE	0
79 #define	CMD_FOUND	1
80 #define	CMD_NONE	2
81 #define	CMD_AMBIGUOUS	3
82 #define	CMD_HELP	4
83 
84 /*
85  * Exported global variables
86  */
87 boolean_t	db_cmd_loop_done;
88 label_t		*db_recover;
89 db_addr_t	db_dot;
90 db_addr_t	db_last_addr;
91 db_addr_t	db_prev;
92 db_addr_t	db_next;
93 
94 /*
95  * if 'ed' style: 'dot' is set at start of last item printed,
96  * and '+' points to next line.
97  * Otherwise: 'dot' points to next item, '..' points to last.
98  */
99 static boolean_t db_ed_style = TRUE;
100 
101 static void	db_buf_print_cmd(db_expr_t, int, db_expr_t, char *);
102 static void	db_cmd_list(const struct db_command *);
103 static int	db_cmd_search(const char *, const struct db_command *,
104 		    const struct db_command **);
105 static void	db_command(const struct db_command **,
106 		    const struct db_command *);
107 static void	db_event_print_cmd(db_expr_t, int, db_expr_t, char *);
108 static void	db_fncall(db_expr_t, int, db_expr_t, char *);
109 static void	db_malloc_print_cmd(db_expr_t, int, db_expr_t, char *);
110 static void	db_map_print_cmd(db_expr_t, int, db_expr_t, char *);
111 static void	db_namecache_print_cmd(db_expr_t, int, db_expr_t, char *);
112 static void	db_object_print_cmd(db_expr_t, int, db_expr_t, char *);
113 static void	db_page_print_cmd(db_expr_t, int, db_expr_t, char *);
114 static void	db_pool_print_cmd(db_expr_t, int, db_expr_t, char *);
115 static void	db_reboot_cmd(db_expr_t, int, db_expr_t, char *);
116 static void	db_sifting_cmd(db_expr_t, int, db_expr_t, char *);
117 static void	db_stack_trace_cmd(db_expr_t, int, db_expr_t, char *);
118 static void	db_sync_cmd(db_expr_t, int, db_expr_t, char *);
119 static void	db_uvmexp_print_cmd(db_expr_t, int, db_expr_t, char *);
120 static void	db_vnode_print_cmd(db_expr_t, int, db_expr_t, char *);
121 
122 /*
123  * 'show' commands
124  */
125 
126 static const struct db_command db_show_all_cmds[] = {
127 	{ "callout",	db_show_callout,	0, NULL },
128 	{ "procs",	db_show_all_procs,	0, NULL },
129 	{ NULL, 	NULL, 			0, NULL }
130 };
131 
132 static const struct db_command db_show_cmds[] = {
133 	{ "all",	NULL,			0,	db_show_all_cmds },
134 #if defined(INET) && (NARP > 0)
135 	{ "arptab",	db_show_arptab,		0,	NULL },
136 #endif
137 	{ "breaks",	db_listbreak_cmd, 	0,	NULL },
138 	{ "buf",	db_buf_print_cmd,	0,	NULL },
139 	{ "event",	db_event_print_cmd,	0,	NULL },
140 	{ "malloc",	db_malloc_print_cmd,	0,	NULL },
141 	{ "map",	db_map_print_cmd,	0,	NULL },
142 	{ "ncache",	db_namecache_print_cmd,	0,	NULL },
143 	{ "object",	db_object_print_cmd,	0,	NULL },
144 	{ "page",	db_page_print_cmd,	0,	NULL },
145 	{ "pool",	db_pool_print_cmd,	0,	NULL },
146 	{ "registers",	db_show_regs,		0,	NULL },
147 	{ "uvmexp",	db_uvmexp_print_cmd,	0,	NULL },
148 	{ "vnode",	db_vnode_print_cmd,	0,	NULL },
149 	{ "watches",	db_listwatch_cmd, 	0,	NULL },
150 	{ NULL,		NULL,			0,	NULL }
151 };
152 
153 static const struct db_command db_command_table[] = {
154 	{ "break",	db_breakpoint_cmd,	0,		NULL },
155 	{ "bt",		db_stack_trace_cmd,	0,		NULL },
156 	{ "c",		db_continue_cmd,	0,		NULL },
157 	{ "call",	db_fncall,		CS_OWN,		NULL },
158 	{ "callout",	db_show_callout,	0,		NULL },
159 	{ "continue",	db_continue_cmd,	0,		NULL },
160 	{ "d",		db_delete_cmd,		0,		NULL },
161 	{ "delete",	db_delete_cmd,		0,		NULL },
162 	{ "dmesg",	db_dmesg,		0,		NULL },
163 	{ "dwatch",	db_deletewatch_cmd,	0,		NULL },
164 	{ "examine",	db_examine_cmd,		CS_SET_DOT, 	NULL },
165 	{ "kill",	db_kill_proc,		CS_OWN,		NULL },
166 #ifdef KGDB
167 	{ "kgdb",	db_kgdb_cmd,		0,		NULL },
168 #endif
169 #ifdef DB_MACHINE_COMMANDS
170 	{ "machine",	NULL,			0, db_machine_command_table },
171 #endif
172 	{ "match",	db_trace_until_matching_cmd,0,		NULL },
173 	{ "next",	db_trace_until_matching_cmd,0,		NULL },
174 	{ "p",		db_print_cmd,		0,		NULL },
175 	{ "print",	db_print_cmd,		0,		NULL },
176 	{ "ps",		db_show_all_procs,	0,		NULL },
177 	{ "reboot",	db_reboot_cmd,		CS_OWN,		NULL },
178 	{ "s",		db_single_step_cmd,	0,		NULL },
179 	{ "search",	db_search_cmd,		CS_OWN|CS_SET_DOT, NULL },
180 	{ "set",	db_set_cmd,		CS_OWN,		NULL },
181 	{ "show",	NULL,			0,		db_show_cmds },
182 	{ "sifting",	db_sifting_cmd,		CS_OWN,		NULL },
183 	{ "step",	db_single_step_cmd,	0,		NULL },
184 	{ "sync",	db_sync_cmd,		CS_OWN,		NULL },
185 	{ "trace",	db_stack_trace_cmd,	0,		NULL },
186 	{ "until",	db_trace_until_call_cmd,0,		NULL },
187 	{ "w",		db_write_cmd,		CS_MORE|CS_SET_DOT, NULL },
188 	{ "watch",	db_watchpoint_cmd,	CS_MORE,	NULL },
189 	{ "write",	db_write_cmd,		CS_MORE|CS_SET_DOT, NULL },
190 	{ "x",		db_examine_cmd,		CS_SET_DOT, 	NULL },
191 	{ NULL, 	NULL,			0,		NULL }
192 };
193 
194 static const struct db_command	*db_last_command = NULL;
195 
196 /*
197  * Utility routine - discard tokens through end-of-line.
198  */
199 void
200 db_skip_to_eol(void)
201 {
202 	int t;
203 
204 	do {
205 		t = db_read_token();
206 	} while (t != tEOL);
207 }
208 
209 void
210 db_error(s)
211 	char *s;
212 {
213 
214 	if (s)
215 		db_printf("%s", s);
216 	db_flush_lex();
217 	longjmp(db_recover);
218 }
219 
220 void
221 db_command_loop(void)
222 {
223 	label_t	db_jmpbuf;
224 	label_t	*savejmp;
225 
226 	/*
227 	 * Initialize 'prev' and 'next' to dot.
228 	 */
229 	db_prev = db_dot;
230 	db_next = db_dot;
231 
232 	db_cmd_loop_done = 0;
233 
234 	savejmp = db_recover;
235 	db_recover = &db_jmpbuf;
236 	(void) setjmp(&db_jmpbuf);
237 
238 	while (!db_cmd_loop_done) {
239 		if (db_print_position() != 0)
240 			db_printf("\n");
241 		db_output_line = 0;
242 
243 
244 #ifdef MULTIPROCESSOR
245 		db_printf("db{%ld}> ", (long)cpu_number());
246 #else
247 		db_printf("db> ");
248 #endif
249 		(void) db_read_line();
250 
251 		db_command(&db_last_command, db_command_table);
252 	}
253 
254 	db_recover = savejmp;
255 }
256 
257 /*
258  * Search for command prefix.
259  */
260 static int
261 db_cmd_search(const char *name, const struct db_command *table,
262     const struct db_command **cmdp)
263 {
264 	const struct db_command	*cmd;
265 	int			result = CMD_NONE;
266 
267 	for (cmd = table; cmd->name != 0; cmd++) {
268 		const char *lp;
269 		const char *rp;
270 		int  c;
271 
272 		lp = name;
273 		rp = cmd->name;
274 		while ((c = *lp) == *rp) {
275 			if (c == 0) {
276 				/* complete match */
277 				*cmdp = cmd;
278 				return (CMD_UNIQUE);
279 			}
280 			lp++;
281 			rp++;
282 		}
283 		if (c == 0) {
284 			/* end of name, not end of command -
285 			   partial match */
286 			if (result == CMD_FOUND) {
287 				result = CMD_AMBIGUOUS;
288 				/* but keep looking for a full match -
289 				   this lets us match single letters */
290 			} else {
291 				*cmdp = cmd;
292 				result = CMD_FOUND;
293 			}
294 		}
295 	}
296 	if (result == CMD_NONE) {
297 		/* check for 'help' */
298 		if (name[0] == 'h' && name[1] == 'e'
299 		    && name[2] == 'l' && name[3] == 'p')
300 			result = CMD_HELP;
301 	}
302 	return (result);
303 }
304 
305 static void
306 db_cmd_list(const struct db_command *table)
307 {
308 	int	 i, j, w, columns, lines, width=0, numcmds;
309 	const char	*p;
310 
311 	for (numcmds = 0; table[numcmds].name != NULL; numcmds++) {
312 		w = strlen(table[numcmds].name);
313 		if (w > width)
314 			width = w;
315 	}
316 	width = DB_NEXT_TAB(width);
317 
318 	columns = db_max_width / width;
319 	if (columns == 0)
320 		columns = 1;
321 	lines = (numcmds + columns - 1) / columns;
322 	for (i = 0; i < lines; i++) {
323 		for (j = 0; j < columns; j++) {
324 			p = table[j * lines + i].name;
325 			if (p)
326 				db_printf("%s", p);
327 			if (j * lines + i + lines >= numcmds) {
328 				db_putchar('\n');
329 				break;
330 			}
331 			w = strlen(p);
332 			while (w < width) {
333 				w = DB_NEXT_TAB(w);
334 				db_putchar('\t');
335 			}
336 		}
337 	}
338 }
339 
340 static void
341 db_command(const struct db_command **last_cmdp,
342     const struct db_command *cmd_table)
343 {
344 	const struct db_command	*cmd;
345 	int		t;
346 	char		modif[TOK_STRING_SIZE];
347 	db_expr_t	addr, count;
348 	boolean_t	have_addr = FALSE;
349 	int		result;
350 
351 	static db_expr_t last_count = 0;
352 
353 	t = db_read_token();
354 	if ((t == tEOL) || (t == tCOMMA)) {
355 		/*
356 		 * An empty line repeats last command, at 'next'.
357 		 * Only a count repeats the last command with the new count.
358 		 */
359 		cmd = *last_cmdp;
360 		addr = (db_expr_t)db_next;
361 		if (t == tCOMMA) {
362 			if (!db_expression(&count)) {
363 				db_printf("Count missing\n");
364 				db_flush_lex();
365 				return;
366 			}
367 		} else
368 			count = last_count;
369 		have_addr = FALSE;
370 		modif[0] = '\0';
371 		db_skip_to_eol();
372 	} else if (t == tEXCL) {
373 		db_fncall(0, 0, 0, NULL);
374 		return;
375 	} else if (t != tIDENT) {
376 		db_printf("?\n");
377 		db_flush_lex();
378 		return;
379 	} else {
380 		/*
381 		 * Search for command
382 		 */
383 		while (cmd_table) {
384 			result = db_cmd_search(db_tok_string, cmd_table, &cmd);
385 			switch (result) {
386 			case CMD_NONE:
387 				db_printf("No such command\n");
388 				db_flush_lex();
389 				return;
390 			case CMD_AMBIGUOUS:
391 				db_printf("Ambiguous\n");
392 				db_flush_lex();
393 				return;
394 			case CMD_HELP:
395 				db_cmd_list(cmd_table);
396 				db_flush_lex();
397 				return;
398 			default:
399 				break;
400 			}
401 			if ((cmd_table = cmd->more) != 0) {
402 				t = db_read_token();
403 				if (t != tIDENT) {
404 					db_cmd_list(cmd_table);
405 					db_flush_lex();
406 					return;
407 				}
408 			}
409 		}
410 
411 		if ((cmd->flag & CS_OWN) == 0) {
412 			/*
413 			 * Standard syntax:
414 			 * command [/modifier] [addr] [,count]
415 			 */
416 			t = db_read_token();
417 			if (t == tSLASH) {
418 				t = db_read_token();
419 				if (t != tIDENT) {
420 					db_printf("Bad modifier\n");
421 					db_flush_lex();
422 					return;
423 				}
424 				strlcpy(modif, db_tok_string, sizeof(modif));
425 			} else {
426 				db_unread_token(t);
427 				modif[0] = '\0';
428 			}
429 
430 			if (db_expression(&addr)) {
431 				db_dot = (db_addr_t) addr;
432 				db_last_addr = db_dot;
433 				have_addr = TRUE;
434 			} else {
435 				addr = (db_expr_t) db_dot;
436 				have_addr = FALSE;
437 			}
438 			t = db_read_token();
439 			if (t == tCOMMA) {
440 				if (!db_expression(&count)) {
441 					db_printf("Count missing\n");
442 					db_flush_lex();
443 					return;
444 				}
445 			} else {
446 				db_unread_token(t);
447 				count = -1;
448 			}
449 			if ((cmd->flag & CS_MORE) == 0) {
450 				db_skip_to_eol();
451 			}
452 		}
453 	}
454 	*last_cmdp = cmd;
455 	last_count = count;
456 	if (cmd != 0) {
457 		/*
458 		 * Execute the command.
459 		 */
460 		(*cmd->fcn)(addr, have_addr, count, modif);
461 
462 		if (cmd->flag & CS_SET_DOT) {
463 			/*
464 			 * If command changes dot, set dot to
465 			 * previous address displayed (if 'ed' style).
466 			 */
467 			if (db_ed_style)
468 				db_dot = db_prev;
469 			else
470 				db_dot = db_next;
471 		} else {
472 			/*
473 			 * If command does not change dot,
474 			 * set 'next' location to be the same.
475 			 */
476 			db_next = db_dot;
477 		}
478 	}
479 }
480 
481 /*ARGSUSED*/
482 static void
483 db_map_print_cmd(db_expr_t addr, int have_addr, db_expr_t count, char *modif)
484 {
485 	boolean_t full = FALSE;
486 
487 	if (modif[0] == 'f')
488 		full = TRUE;
489 
490 	if (have_addr == FALSE)
491 		addr = (db_expr_t)(intptr_t) kernel_map;
492 
493 	uvm_map_printit((struct vm_map *)(intptr_t) addr, full, db_printf);
494 }
495 
496 /*ARGSUSED*/
497 static void
498 db_malloc_print_cmd(db_expr_t addr, int have_addr, db_expr_t count, char *modif)
499 {
500 
501 #ifdef MALLOC_DEBUG
502 	if (!have_addr)
503 		addr = 0;
504 
505 	debug_malloc_printit(db_printf, (vaddr_t) addr);
506 #else
507 	db_printf("The kernel is not built with the MALLOC_DEBUG option.\n");
508 #endif /* MALLOC_DEBUG */
509 }
510 
511 /*ARGSUSED*/
512 static void
513 db_object_print_cmd(db_expr_t addr, int have_addr, db_expr_t count, char *modif)
514 {
515 	boolean_t full = FALSE;
516 
517 	if (modif[0] == 'f')
518 		full = TRUE;
519 
520 	uvm_object_printit((struct uvm_object *)(intptr_t) addr, full,
521 	    db_printf);
522 }
523 
524 /*ARGSUSED*/
525 static void
526 db_page_print_cmd(db_expr_t addr, int have_addr, db_expr_t count, char *modif)
527 {
528 	boolean_t full = FALSE;
529 
530 	if (modif[0] == 'f')
531 		full = TRUE;
532 
533 	uvm_page_printit((struct vm_page *)(intptr_t) addr, full, db_printf);
534 }
535 
536 /*ARGSUSED*/
537 static void
538 db_buf_print_cmd(db_expr_t addr, int have_addr, db_expr_t count, char *modif)
539 {
540 	boolean_t full = FALSE;
541 
542 	if (modif[0] == 'f')
543 		full = TRUE;
544 
545 	vfs_buf_print((struct buf *)(intptr_t) addr, full, db_printf);
546 }
547 
548 /*ARGSUSED*/
549 static void
550 db_event_print_cmd(db_expr_t addr, int have_addr, db_expr_t count, char *modif)
551 {
552 	boolean_t full = FALSE;
553 
554 	if (modif[0] == 'f')
555 		full = TRUE;
556 
557 	event_print(full, db_printf);
558 }
559 
560 /*ARGSUSED*/
561 static void
562 db_vnode_print_cmd(db_expr_t addr, int have_addr, db_expr_t count, char *modif)
563 {
564 	boolean_t full = FALSE;
565 
566 	if (modif[0] == 'f')
567 		full = TRUE;
568 
569 	vfs_vnode_print((struct vnode *)(intptr_t) addr, full, db_printf);
570 }
571 
572 /*ARGSUSED*/
573 static void
574 db_pool_print_cmd(db_expr_t addr, int have_addr, db_expr_t count, char *modif)
575 {
576 
577 	pool_printit((struct pool *)(intptr_t) addr, modif, db_printf);
578 }
579 
580 /*ARGSUSED*/
581 static void
582 db_namecache_print_cmd(db_expr_t addr, int have_addr, db_expr_t count,
583     char *modif)
584 {
585 
586 	namecache_print((struct vnode *)(intptr_t) addr, db_printf);
587 }
588 
589 /*ARGSUSED*/
590 static void
591 db_uvmexp_print_cmd(db_expr_t addr, int have_addr, db_expr_t count, char *modif)
592 {
593 
594 	uvmexp_print(db_printf);
595 }
596 
597 /*
598  * Call random function:
599  * !expr(arg,arg,arg)
600  */
601 /*ARGSUSED*/
602 static void
603 db_fncall(db_expr_t addr, int have_addr, db_expr_t count, char *modif)
604 {
605 	db_expr_t	fn_addr;
606 #define	MAXARGS		11
607 	db_expr_t	args[MAXARGS];
608 	int		nargs = 0;
609 	db_expr_t	retval;
610 	db_expr_t	(*func)(db_expr_t, ...);
611 	int		t;
612 
613 	if (!db_expression(&fn_addr)) {
614 		db_printf("Bad function\n");
615 		db_flush_lex();
616 		return;
617 	}
618 	func = (db_expr_t (*)(db_expr_t, ...))(intptr_t) fn_addr;
619 
620 	t = db_read_token();
621 	if (t == tLPAREN) {
622 		if (db_expression(&args[0])) {
623 			nargs++;
624 			while ((t = db_read_token()) == tCOMMA) {
625 				if (nargs == MAXARGS) {
626 					db_printf("Too many arguments\n");
627 					db_flush_lex();
628 					return;
629 				}
630 				if (!db_expression(&args[nargs])) {
631 					db_printf("Argument missing\n");
632 					db_flush_lex();
633 					return;
634 				}
635 				nargs++;
636 			}
637 			db_unread_token(t);
638 		}
639 		if (db_read_token() != tRPAREN) {
640 			db_printf("?\n");
641 			db_flush_lex();
642 			return;
643 		}
644 	}
645 	db_skip_to_eol();
646 
647 	while (nargs < MAXARGS) {
648 		args[nargs++] = 0;
649 	}
650 
651 	retval = (*func)(args[0], args[1], args[2], args[3], args[4],
652 			 args[5], args[6], args[7], args[8], args[9]);
653 	db_printf("%s\n", db_num_to_str(retval));
654 }
655 
656 static void
657 db_reboot_cmd(db_expr_t addr, int have_addr, db_expr_t count, char *modif)
658 {
659 	db_expr_t bootflags;
660 
661 	/* Flags, default to RB_AUTOBOOT */
662 	if (!db_expression(&bootflags))
663 		bootflags = (db_expr_t)RB_AUTOBOOT;
664 	if (db_read_token() != tEOL) {
665 		db_error("?\n");
666 		/*NOTREACHED*/
667 	}
668 	/*
669 	 * We are leaving DDB, never to return upward.
670 	 * Clear db_recover so that we can debug faults in functions
671 	 * called from cpu_reboot.
672 	 */
673 	db_recover = 0;
674 	cpu_reboot((int)bootflags, NULL);
675 }
676 
677 static void
678 db_sifting_cmd(db_expr_t addr, int have_addr, db_expr_t count, char *modif)
679 {
680 	int	mode, t;
681 
682 	t = db_read_token();
683 	if (t == tSLASH) {
684 		t = db_read_token();
685 		if (t != tIDENT) {
686 			bad_modifier:
687 			db_printf("Bad modifier\n");
688 			db_flush_lex();
689 			return;
690 		}
691 		if (!strcmp(db_tok_string, "F"))
692 			mode = 'F';
693 		else
694 			goto bad_modifier;
695 		t = db_read_token();
696 	} else
697 		mode = 0;
698 
699 	if (t == tIDENT)
700 		db_sifting(db_tok_string, mode);
701 	else {
702 		db_printf("Bad argument (non-string)\n");
703 		db_flush_lex();
704 	}
705 }
706 
707 static void
708 db_stack_trace_cmd(db_expr_t addr, int have_addr, db_expr_t count, char *modif)
709 {
710 	register char *cp = modif;
711 	register char c;
712 	void (*pr)(const char *, ...);
713 
714 	pr = db_printf;
715 	while ((c = *cp++) != 0)
716 		if (c == 'l')
717 			pr = printf;
718 
719 	if (count == -1)
720 		count = 65535;
721 
722 	db_stack_trace_print(addr, have_addr, count, modif, pr);
723 }
724 
725 static void
726 db_sync_cmd(db_expr_t addr, int have_addr, db_expr_t count, char *modif)
727 {
728 
729 	/*
730 	 * We are leaving DDB, never to return upward.
731 	 * Clear db_recover so that we can debug faults in functions
732 	 * called from cpu_reboot.
733 	 */
734 	db_recover = 0;
735 	cpu_reboot(RB_DUMP, NULL);
736 }
737