xref: /netbsd-src/sys/ddb/db_command.c (revision b8c616269f5ebf18ab2e35cb8099d683130a177c)
1 /*	$NetBSD: db_command.c,v 1.67 2003/01/20 07:20:01 simonb 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 1.67 2003/01/20 07:20:01 simonb Exp $");
35 
36 #include "opt_ddb.h"
37 #include "opt_inet.h"
38 
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/reboot.h>
42 #include <sys/device.h>
43 #include <sys/malloc.h>
44 #include <sys/namei.h>
45 #include <sys/pool.h>
46 #include <sys/proc.h>
47 #include <sys/vnode.h>
48 
49 #include <machine/db_machdep.h>		/* type definitions */
50 
51 #if defined(_KERNEL_OPT)
52 #include "opt_multiprocessor.h"
53 #endif
54 #ifdef MULTIPROCESSOR
55 #include <machine/cpu.h>
56 #endif
57 
58 #include <ddb/db_lex.h>
59 #include <ddb/db_output.h>
60 #include <ddb/db_command.h>
61 #include <ddb/db_break.h>
62 #include <ddb/db_watch.h>
63 #include <ddb/db_run.h>
64 #include <ddb/db_variables.h>
65 #include <ddb/db_interface.h>
66 #include <ddb/db_sym.h>
67 #include <ddb/db_extern.h>
68 
69 #include <uvm/uvm_extern.h>
70 #include <uvm/uvm_ddb.h>
71 
72 #include "arp.h"
73 
74 /*
75  * Results of command search.
76  */
77 #define	CMD_UNIQUE	0
78 #define	CMD_FOUND	1
79 #define	CMD_NONE	2
80 #define	CMD_AMBIGUOUS	3
81 #define	CMD_HELP	4
82 
83 /*
84  * Exported global variables
85  */
86 boolean_t	db_cmd_loop_done;
87 label_t		*db_recover;
88 db_addr_t	db_dot;
89 db_addr_t	db_last_addr;
90 db_addr_t	db_prev;
91 db_addr_t	db_next;
92 
93 /*
94  * if 'ed' style: 'dot' is set at start of last item printed,
95  * and '+' points to next line.
96  * Otherwise: 'dot' points to next item, '..' points to last.
97  */
98 static boolean_t db_ed_style = TRUE;
99 
100 static void	db_buf_print_cmd(db_expr_t, int, db_expr_t, char *);
101 static void	db_cmd_list(const struct db_command *);
102 static int	db_cmd_search(const char *, const struct db_command *,
103 		    const struct db_command **);
104 static void	db_command(const struct db_command **,
105 		    const struct db_command *);
106 static void	db_event_print_cmd(db_expr_t, int, db_expr_t, char *);
107 static void	db_fncall(db_expr_t, int, db_expr_t, char *);
108 static void	db_malloc_print_cmd(db_expr_t, int, db_expr_t, char *);
109 static void	db_map_print_cmd(db_expr_t, int, db_expr_t, char *);
110 static void	db_namecache_print_cmd(db_expr_t, int, db_expr_t, char *);
111 static void	db_object_print_cmd(db_expr_t, int, db_expr_t, char *);
112 static void	db_page_print_cmd(db_expr_t, int, db_expr_t, char *);
113 static void	db_pool_print_cmd(db_expr_t, int, db_expr_t, char *);
114 static void	db_reboot_cmd(db_expr_t, int, db_expr_t, char *);
115 static void	db_sifting_cmd(db_expr_t, int, db_expr_t, char *);
116 static void	db_stack_trace_cmd(db_expr_t, int, db_expr_t, char *);
117 static void	db_sync_cmd(db_expr_t, int, db_expr_t, char *);
118 static void	db_uvmexp_print_cmd(db_expr_t, int, db_expr_t, char *);
119 static void	db_vnode_print_cmd(db_expr_t, int, db_expr_t, char *);
120 
121 /*
122  * 'show' commands
123  */
124 
125 static const struct db_command db_show_all_cmds[] = {
126 	{ "callout",	db_show_callout,	0, NULL },
127 	{ "procs",	db_show_all_procs,	0, NULL },
128 	{ NULL, 	NULL, 			0, NULL }
129 };
130 
131 static const struct db_command db_show_cmds[] = {
132 	{ "all",	NULL,			0,	db_show_all_cmds },
133 #if defined(INET) && (NARP > 0)
134 	{ "arptab",	db_show_arptab,		0,	NULL },
135 #endif
136 	{ "breaks",	db_listbreak_cmd, 	0,	NULL },
137 	{ "buf",	db_buf_print_cmd,	0,	NULL },
138 	{ "event",	db_event_print_cmd,	0,	NULL },
139 	{ "malloc",	db_malloc_print_cmd,	0,	NULL },
140 	{ "map",	db_map_print_cmd,	0,	NULL },
141 	{ "ncache",	db_namecache_print_cmd,	0,	NULL },
142 	{ "object",	db_object_print_cmd,	0,	NULL },
143 	{ "page",	db_page_print_cmd,	0,	NULL },
144 	{ "pool",	db_pool_print_cmd,	0,	NULL },
145 	{ "registers",	db_show_regs,		0,	NULL },
146 	{ "uvmexp",	db_uvmexp_print_cmd,	0,	NULL },
147 	{ "vnode",	db_vnode_print_cmd,	0,	NULL },
148 	{ "watches",	db_listwatch_cmd, 	0,	NULL },
149 	{ NULL,		NULL,			0,	NULL }
150 };
151 
152 static const struct db_command db_command_table[] = {
153 	{ "break",	db_breakpoint_cmd,	0,		NULL },
154 	{ "c",		db_continue_cmd,	0,		NULL },
155 	{ "call",	db_fncall,		CS_OWN,		NULL },
156 	{ "callout",	db_show_callout,	0,		NULL },
157 	{ "continue",	db_continue_cmd,	0,		NULL },
158 	{ "d",		db_delete_cmd,		0,		NULL },
159 	{ "delete",	db_delete_cmd,		0,		NULL },
160 	{ "dmesg",	db_dmesg,		0,		NULL },
161 	{ "dwatch",	db_deletewatch_cmd,	0,		NULL },
162 	{ "examine",	db_examine_cmd,		CS_SET_DOT, 	NULL },
163 	{ "kill",	db_kill_proc,		CS_OWN,		NULL },
164 #ifdef DB_MACHINE_COMMANDS
165 	{ "machine",	NULL,			0, db_machine_command_table },
166 #endif
167 	{ "match",	db_trace_until_matching_cmd,0,		NULL },
168 	{ "next",	db_trace_until_matching_cmd,0,		NULL },
169 	{ "p",		db_print_cmd,		0,		NULL },
170 	{ "print",	db_print_cmd,		0,		NULL },
171 	{ "ps",		db_show_all_procs,	0,		NULL },
172 	{ "reboot",	db_reboot_cmd,		CS_OWN,		NULL },
173 	{ "s",		db_single_step_cmd,	0,		NULL },
174 	{ "search",	db_search_cmd,		CS_OWN|CS_SET_DOT, NULL },
175 	{ "set",	db_set_cmd,		CS_OWN,		NULL },
176 	{ "show",	NULL,			0,		db_show_cmds },
177 	{ "sifting",	db_sifting_cmd,		CS_OWN,		NULL },
178 	{ "step",	db_single_step_cmd,	0,		NULL },
179 	{ "sync",	db_sync_cmd,		CS_OWN,		NULL },
180 	{ "trace",	db_stack_trace_cmd,	0,		NULL },
181 	{ "until",	db_trace_until_call_cmd,0,		NULL },
182 	{ "w",		db_write_cmd,		CS_MORE|CS_SET_DOT, NULL },
183 	{ "watch",	db_watchpoint_cmd,	CS_MORE,	NULL },
184 	{ "write",	db_write_cmd,		CS_MORE|CS_SET_DOT, NULL },
185 	{ "x",		db_examine_cmd,		CS_SET_DOT, 	NULL },
186 	{ NULL, 	NULL,			0,		NULL }
187 };
188 
189 static const struct db_command	*db_last_command = NULL;
190 
191 /*
192  * Utility routine - discard tokens through end-of-line.
193  */
194 void
195 db_skip_to_eol(void)
196 {
197 	int t;
198 
199 	do {
200 		t = db_read_token();
201 	} while (t != tEOL);
202 }
203 
204 void
205 db_error(s)
206 	char *s;
207 {
208 
209 	if (s)
210 		db_printf("%s", s);
211 	db_flush_lex();
212 	longjmp(db_recover);
213 }
214 
215 void
216 db_command_loop(void)
217 {
218 	label_t	db_jmpbuf;
219 	label_t	*savejmp;
220 
221 	/*
222 	 * Initialize 'prev' and 'next' to dot.
223 	 */
224 	db_prev = db_dot;
225 	db_next = db_dot;
226 
227 	db_cmd_loop_done = 0;
228 
229 	savejmp = db_recover;
230 	db_recover = &db_jmpbuf;
231 	(void) setjmp(&db_jmpbuf);
232 
233 	while (!db_cmd_loop_done) {
234 		if (db_print_position() != 0)
235 			db_printf("\n");
236 		db_output_line = 0;
237 
238 
239 #ifdef MULTIPROCESSOR
240 		db_printf("db{%ld}> ", (long)cpu_number());
241 #else
242 		db_printf("db> ");
243 #endif
244 		(void) db_read_line();
245 
246 		db_command(&db_last_command, db_command_table);
247 	}
248 
249 	db_recover = savejmp;
250 }
251 
252 /*
253  * Search for command prefix.
254  */
255 static int
256 db_cmd_search(const char *name, const struct db_command *table,
257     const struct db_command **cmdp)
258 {
259 	const struct db_command	*cmd;
260 	int			result = CMD_NONE;
261 
262 	for (cmd = table; cmd->name != 0; cmd++) {
263 		const char *lp;
264 		const char *rp;
265 		int  c;
266 
267 		lp = name;
268 		rp = cmd->name;
269 		while ((c = *lp) == *rp) {
270 			if (c == 0) {
271 				/* complete match */
272 				*cmdp = cmd;
273 				return (CMD_UNIQUE);
274 			}
275 			lp++;
276 			rp++;
277 		}
278 		if (c == 0) {
279 			/* end of name, not end of command -
280 			   partial match */
281 			if (result == CMD_FOUND) {
282 				result = CMD_AMBIGUOUS;
283 				/* but keep looking for a full match -
284 				   this lets us match single letters */
285 			} else {
286 				*cmdp = cmd;
287 				result = CMD_FOUND;
288 			}
289 		}
290 	}
291 	if (result == CMD_NONE) {
292 		/* check for 'help' */
293 		if (name[0] == 'h' && name[1] == 'e'
294 		    && name[2] == 'l' && name[3] == 'p')
295 			result = CMD_HELP;
296 	}
297 	return (result);
298 }
299 
300 static void
301 db_cmd_list(const struct db_command *table)
302 {
303 	int	 i, j, w, columns, lines, width=0, numcmds;
304 	const char	*p;
305 
306 	for (numcmds = 0; table[numcmds].name != NULL; numcmds++) {
307 		w = strlen(table[numcmds].name);
308 		if (w > width)
309 			width = w;
310 	}
311 	width = DB_NEXT_TAB(width);
312 
313 	columns = db_max_width / width;
314 	if (columns == 0)
315 		columns = 1;
316 	lines = (numcmds + columns - 1) / columns;
317 	for (i = 0; i < lines; i++) {
318 		for (j = 0; j < columns; j++) {
319 			p = table[j * lines + i].name;
320 			if (p)
321 				db_printf("%s", p);
322 			if (j * lines + i + lines >= numcmds) {
323 				db_putchar('\n');
324 				break;
325 			}
326 			w = strlen(p);
327 			while (w < width) {
328 				w = DB_NEXT_TAB(w);
329 				db_putchar('\t');
330 			}
331 		}
332 	}
333 }
334 
335 static void
336 db_command(const struct db_command **last_cmdp,
337     const struct db_command *cmd_table)
338 {
339 	const struct db_command	*cmd;
340 	int		t;
341 	char		modif[TOK_STRING_SIZE];
342 	db_expr_t	addr, count;
343 	boolean_t	have_addr = FALSE;
344 	int		result;
345 
346 	static db_expr_t last_count = 0;
347 
348 	t = db_read_token();
349 	if ((t == tEOL) || (t == tCOMMA)) {
350 		/*
351 		 * An empty line repeats last command, at 'next'.
352 		 * Only a count repeats the last command with the new count.
353 		 */
354 		cmd = *last_cmdp;
355 		addr = (db_expr_t)db_next;
356 		if (t == tCOMMA) {
357 			if (!db_expression(&count)) {
358 				db_printf("Count missing\n");
359 				db_flush_lex();
360 				return;
361 			}
362 		} else
363 			count = last_count;
364 		have_addr = FALSE;
365 		modif[0] = '\0';
366 		db_skip_to_eol();
367 	} else if (t == tEXCL) {
368 		db_fncall(0, 0, 0, NULL);
369 		return;
370 	} else if (t != tIDENT) {
371 		db_printf("?\n");
372 		db_flush_lex();
373 		return;
374 	} else {
375 		/*
376 		 * Search for command
377 		 */
378 		while (cmd_table) {
379 			result = db_cmd_search(db_tok_string, cmd_table, &cmd);
380 			switch (result) {
381 			case CMD_NONE:
382 				db_printf("No such command\n");
383 				db_flush_lex();
384 				return;
385 			case CMD_AMBIGUOUS:
386 				db_printf("Ambiguous\n");
387 				db_flush_lex();
388 				return;
389 			case CMD_HELP:
390 				db_cmd_list(cmd_table);
391 				db_flush_lex();
392 				return;
393 			default:
394 				break;
395 			}
396 			if ((cmd_table = cmd->more) != 0) {
397 				t = db_read_token();
398 				if (t != tIDENT) {
399 					db_cmd_list(cmd_table);
400 					db_flush_lex();
401 					return;
402 				}
403 			}
404 		}
405 
406 		if ((cmd->flag & CS_OWN) == 0) {
407 			/*
408 			 * Standard syntax:
409 			 * command [/modifier] [addr] [,count]
410 			 */
411 			t = db_read_token();
412 			if (t == tSLASH) {
413 				t = db_read_token();
414 				if (t != tIDENT) {
415 					db_printf("Bad modifier\n");
416 					db_flush_lex();
417 					return;
418 				}
419 				db_strcpy(modif, db_tok_string);
420 			} else {
421 				db_unread_token(t);
422 				modif[0] = '\0';
423 			}
424 
425 			if (db_expression(&addr)) {
426 				db_dot = (db_addr_t) addr;
427 				db_last_addr = db_dot;
428 				have_addr = TRUE;
429 			} else {
430 				addr = (db_expr_t) db_dot;
431 				have_addr = FALSE;
432 			}
433 			t = db_read_token();
434 			if (t == tCOMMA) {
435 				if (!db_expression(&count)) {
436 					db_printf("Count missing\n");
437 					db_flush_lex();
438 					return;
439 				}
440 			} else {
441 				db_unread_token(t);
442 				count = -1;
443 			}
444 			if ((cmd->flag & CS_MORE) == 0) {
445 				db_skip_to_eol();
446 			}
447 		}
448 	}
449 	*last_cmdp = cmd;
450 	last_count = count;
451 	if (cmd != 0) {
452 		/*
453 		 * Execute the command.
454 		 */
455 		(*cmd->fcn)(addr, have_addr, count, modif);
456 
457 		if (cmd->flag & CS_SET_DOT) {
458 			/*
459 			 * If command changes dot, set dot to
460 			 * previous address displayed (if 'ed' style).
461 			 */
462 			if (db_ed_style)
463 				db_dot = db_prev;
464 			else
465 				db_dot = db_next;
466 		} else {
467 			/*
468 			 * If command does not change dot,
469 			 * set 'next' location to be the same.
470 			 */
471 			db_next = db_dot;
472 		}
473 	}
474 }
475 
476 /*ARGSUSED*/
477 static void
478 db_map_print_cmd(db_expr_t addr, int have_addr, db_expr_t count, char *modif)
479 {
480 	boolean_t full = FALSE;
481 
482 	if (modif[0] == 'f')
483 		full = TRUE;
484 
485 	if (have_addr == FALSE)
486 		addr = (db_expr_t)(intptr_t) kernel_map;
487 
488 	uvm_map_printit((struct vm_map *)(intptr_t) addr, full, db_printf);
489 }
490 
491 /*ARGSUSED*/
492 static void
493 db_malloc_print_cmd(db_expr_t addr, int have_addr, db_expr_t count, char *modif)
494 {
495 
496 #ifdef MALLOC_DEBUG
497 	if (!have_addr)
498 		addr = 0;
499 
500 	debug_malloc_printit(db_printf, (vaddr_t) addr);
501 #else
502 	db_printf("The kernel is not built with the MALLOC_DEBUG option.\n");
503 #endif /* MALLOC_DEBUG */
504 }
505 
506 /*ARGSUSED*/
507 static void
508 db_object_print_cmd(db_expr_t addr, int have_addr, db_expr_t count, char *modif)
509 {
510 	boolean_t full = FALSE;
511 
512 	if (modif[0] == 'f')
513 		full = TRUE;
514 
515 	uvm_object_printit((struct uvm_object *)(intptr_t) addr, full,
516 	    db_printf);
517 }
518 
519 /*ARGSUSED*/
520 static void
521 db_page_print_cmd(db_expr_t addr, int have_addr, db_expr_t count, char *modif)
522 {
523 	boolean_t full = FALSE;
524 
525 	if (modif[0] == 'f')
526 		full = TRUE;
527 
528 	uvm_page_printit((struct vm_page *)(intptr_t) addr, full, db_printf);
529 }
530 
531 /*ARGSUSED*/
532 static void
533 db_buf_print_cmd(db_expr_t addr, int have_addr, db_expr_t count, char *modif)
534 {
535 	boolean_t full = FALSE;
536 
537 	if (modif[0] == 'f')
538 		full = TRUE;
539 
540 	vfs_buf_print((struct buf *)(intptr_t) addr, full, db_printf);
541 }
542 
543 /*ARGSUSED*/
544 static void
545 db_event_print_cmd(db_expr_t addr, int have_addr, db_expr_t count, char *modif)
546 {
547 	boolean_t full = FALSE;
548 
549 	if (modif[0] == 'f')
550 		full = TRUE;
551 
552 	event_print(full, db_printf);
553 }
554 
555 /*ARGSUSED*/
556 static void
557 db_vnode_print_cmd(db_expr_t addr, int have_addr, db_expr_t count, char *modif)
558 {
559 	boolean_t full = FALSE;
560 
561 	if (modif[0] == 'f')
562 		full = TRUE;
563 
564 	vfs_vnode_print((struct vnode *)(intptr_t) addr, full, db_printf);
565 }
566 
567 /*ARGSUSED*/
568 static void
569 db_pool_print_cmd(db_expr_t addr, int have_addr, db_expr_t count, char *modif)
570 {
571 
572 	pool_printit((struct pool *)(intptr_t) addr, modif, db_printf);
573 }
574 
575 /*ARGSUSED*/
576 static void
577 db_namecache_print_cmd(db_expr_t addr, int have_addr, db_expr_t count,
578     char *modif)
579 {
580 
581 	namecache_print((struct vnode *)(intptr_t) addr, db_printf);
582 }
583 
584 /*ARGSUSED*/
585 static void
586 db_uvmexp_print_cmd(db_expr_t addr, int have_addr, db_expr_t count, char *modif)
587 {
588 
589 	uvmexp_print(db_printf);
590 }
591 
592 /*
593  * Call random function:
594  * !expr(arg,arg,arg)
595  */
596 /*ARGSUSED*/
597 static void
598 db_fncall(db_expr_t addr, int have_addr, db_expr_t count, char *modif)
599 {
600 	db_expr_t	fn_addr;
601 #define	MAXARGS		11
602 	db_expr_t	args[MAXARGS];
603 	int		nargs = 0;
604 	db_expr_t	retval;
605 	db_expr_t	(*func)(db_expr_t, ...);
606 	int		t;
607 
608 	if (!db_expression(&fn_addr)) {
609 		db_printf("Bad function\n");
610 		db_flush_lex();
611 		return;
612 	}
613 	func = (db_expr_t (*)(db_expr_t, ...))(intptr_t) fn_addr;
614 
615 	t = db_read_token();
616 	if (t == tLPAREN) {
617 		if (db_expression(&args[0])) {
618 			nargs++;
619 			while ((t = db_read_token()) == tCOMMA) {
620 				if (nargs == MAXARGS) {
621 					db_printf("Too many arguments\n");
622 					db_flush_lex();
623 					return;
624 				}
625 				if (!db_expression(&args[nargs])) {
626 					db_printf("Argument missing\n");
627 					db_flush_lex();
628 					return;
629 				}
630 				nargs++;
631 			}
632 			db_unread_token(t);
633 		}
634 		if (db_read_token() != tRPAREN) {
635 			db_printf("?\n");
636 			db_flush_lex();
637 			return;
638 		}
639 	}
640 	db_skip_to_eol();
641 
642 	while (nargs < MAXARGS) {
643 		args[nargs++] = 0;
644 	}
645 
646 	retval = (*func)(args[0], args[1], args[2], args[3], args[4],
647 			 args[5], args[6], args[7], args[8], args[9]);
648 	db_printf("%s\n", db_num_to_str(retval));
649 }
650 
651 static void
652 db_reboot_cmd(db_expr_t addr, int have_addr, db_expr_t count, char *modif)
653 {
654 	db_expr_t bootflags;
655 
656 	/* Flags, default to RB_AUTOBOOT */
657 	if (!db_expression(&bootflags))
658 		bootflags = (db_expr_t)RB_AUTOBOOT;
659 	if (db_read_token() != tEOL) {
660 		db_error("?\n");
661 		/*NOTREACHED*/
662 	}
663 	/*
664 	 * We are leaving DDB, never to return upward.
665 	 * Clear db_recover so that we can debug faults in functions
666 	 * called from cpu_reboot.
667 	 */
668 	db_recover = 0;
669 	cpu_reboot((int)bootflags, NULL);
670 }
671 
672 static void
673 db_sifting_cmd(db_expr_t addr, int have_addr, db_expr_t count, char *modif)
674 {
675 	int	mode, t;
676 
677 	t = db_read_token();
678 	if (t == tSLASH) {
679 		t = db_read_token();
680 		if (t != tIDENT) {
681 			bad_modifier:
682 			db_printf("Bad modifier\n");
683 			db_flush_lex();
684 			return;
685 		}
686 		if (!strcmp(db_tok_string, "F"))
687 			mode = 'F';
688 		else
689 			goto bad_modifier;
690 		t = db_read_token();
691 	} else
692 		mode = 0;
693 
694 	if (t == tIDENT)
695 		db_sifting(db_tok_string, mode);
696 	else {
697 		db_printf("Bad argument (non-string)\n");
698 		db_flush_lex();
699 	}
700 }
701 
702 static void
703 db_stack_trace_cmd(db_expr_t addr, int have_addr, db_expr_t count, char *modif)
704 {
705 
706 	if (count == -1)
707 		count = 65535;
708 
709 	db_stack_trace_print(addr, have_addr, count, modif, db_printf);
710 }
711 
712 static void
713 db_sync_cmd(db_expr_t addr, int have_addr, db_expr_t count, char *modif)
714 {
715 
716 	/*
717 	 * We are leaving DDB, never to return upward.
718 	 * Clear db_recover so that we can debug faults in functions
719 	 * called from cpu_reboot.
720 	 */
721 	db_recover = 0;
722 	cpu_reboot(RB_DUMP, NULL);
723 }
724