xref: /freebsd/sys/ddb/db_command.c (revision 6829dae12bb055451fa467da4589c43bd03b1e64)
1 /*-
2  * SPDX-License-Identifier: MIT-CMU
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
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  *	Author: David B. Golub, Carnegie Mellon University
30  *	Date:	7/90
31  */
32 /*
33  * Command dispatcher.
34  */
35 
36 #include <sys/cdefs.h>
37 __FBSDID("$FreeBSD$");
38 
39 #include <sys/param.h>
40 #include <sys/linker_set.h>
41 #include <sys/lock.h>
42 #include <sys/kdb.h>
43 #include <sys/mutex.h>
44 #include <sys/proc.h>
45 #include <sys/reboot.h>
46 #include <sys/signalvar.h>
47 #include <sys/systm.h>
48 #include <sys/cons.h>
49 #include <sys/conf.h>
50 #include <sys/watchdog.h>
51 #include <sys/kernel.h>
52 
53 #include <ddb/ddb.h>
54 #include <ddb/db_command.h>
55 #include <ddb/db_lex.h>
56 #include <ddb/db_output.h>
57 
58 #include <machine/cpu.h>
59 #include <machine/setjmp.h>
60 
61 /*
62  * Exported global variables
63  */
64 int		db_cmd_loop_done;
65 db_addr_t	db_dot;
66 db_addr_t	db_last_addr;
67 db_addr_t	db_prev;
68 db_addr_t	db_next;
69 
70 static db_cmdfcn_t	db_dump;
71 static db_cmdfcn_t	db_fncall;
72 static db_cmdfcn_t	db_gdb;
73 static db_cmdfcn_t	db_halt;
74 static db_cmdfcn_t	db_kill;
75 static db_cmdfcn_t	db_reset;
76 static db_cmdfcn_t	db_stack_trace;
77 static db_cmdfcn_t	db_stack_trace_active;
78 static db_cmdfcn_t	db_stack_trace_all;
79 static db_cmdfcn_t	db_watchdog;
80 
81 /*
82  * 'show' commands
83  */
84 
85 static struct command db_show_active_cmds[] = {
86 	{ "trace",	db_stack_trace_active,	0,	NULL },
87 };
88 struct command_table db_show_active_table =
89     LIST_HEAD_INITIALIZER(db_show_active_table);
90 
91 static struct command db_show_all_cmds[] = {
92 	{ "trace",	db_stack_trace_all,	0,	NULL },
93 };
94 struct command_table db_show_all_table =
95     LIST_HEAD_INITIALIZER(db_show_all_table);
96 
97 static struct command db_show_cmds[] = {
98 	{ "active",	0,			0,	&db_show_active_table },
99 	{ "all",	0,			0,	&db_show_all_table },
100 	{ "registers",	db_show_regs,		0,	NULL },
101 	{ "breaks",	db_listbreak_cmd, 	0,	NULL },
102 	{ "threads",	db_show_threads,	0,	NULL },
103 };
104 struct command_table db_show_table = LIST_HEAD_INITIALIZER(db_show_table);
105 
106 static struct command db_cmds[] = {
107 	{ "print",	db_print_cmd,		0,	NULL },
108 	{ "p",		db_print_cmd,		0,	NULL },
109 	{ "examine",	db_examine_cmd,		CS_SET_DOT, NULL },
110 	{ "x",		db_examine_cmd,		CS_SET_DOT, NULL },
111 	{ "search",	db_search_cmd,		CS_OWN|CS_SET_DOT, NULL },
112 	{ "set",	db_set_cmd,		CS_OWN,	NULL },
113 	{ "write",	db_write_cmd,		CS_MORE|CS_SET_DOT, NULL },
114 	{ "w",		db_write_cmd,		CS_MORE|CS_SET_DOT, NULL },
115 	{ "delete",	db_delete_cmd,		0,	NULL },
116 	{ "d",		db_delete_cmd,		0,	NULL },
117 	{ "dump",	db_dump,		0,	NULL },
118 	{ "break",	db_breakpoint_cmd,	0,	NULL },
119 	{ "b",		db_breakpoint_cmd,	0,	NULL },
120 	{ "dwatch",	db_deletewatch_cmd,	0,	NULL },
121 	{ "watch",	db_watchpoint_cmd,	CS_MORE,NULL },
122 	{ "dhwatch",	db_deletehwatch_cmd,	0,      NULL },
123 	{ "hwatch",	db_hwatchpoint_cmd,	0,      NULL },
124 	{ "step",	db_single_step_cmd,	0,	NULL },
125 	{ "s",		db_single_step_cmd,	0,	NULL },
126 	{ "continue",	db_continue_cmd,	0,	NULL },
127 	{ "c",		db_continue_cmd,	0,	NULL },
128 	{ "until",	db_trace_until_call_cmd,0,	NULL },
129 	{ "next",	db_trace_until_matching_cmd,0,	NULL },
130 	{ "match",	db_trace_until_matching_cmd,0,	NULL },
131 	{ "trace",	db_stack_trace,		CS_OWN,	NULL },
132 	{ "t",		db_stack_trace,		CS_OWN,	NULL },
133 	/* XXX alias for active trace */
134 	{ "acttrace",	db_stack_trace_active,	0,	NULL },
135 	/* XXX alias for all trace */
136 	{ "alltrace",	db_stack_trace_all,	0,	NULL },
137 	{ "where",	db_stack_trace,		CS_OWN,	NULL },
138 	{ "bt",		db_stack_trace,		CS_OWN,	NULL },
139 	{ "call",	db_fncall,		CS_OWN,	NULL },
140 	{ "show",	0,			0,	&db_show_table },
141 	{ "ps",		db_ps,			0,	NULL },
142 	{ "gdb",	db_gdb,			0,	NULL },
143 	{ "halt",	db_halt,		0,	NULL },
144 	{ "reboot",	db_reset,		0,	NULL },
145 	{ "reset",	db_reset,		0,	NULL },
146 	{ "kill",	db_kill,		CS_OWN,	NULL },
147 	{ "watchdog",	db_watchdog,		CS_OWN,	NULL },
148 	{ "thread",	db_set_thread,		0,	NULL },
149 	{ "run",	db_run_cmd,		CS_OWN,	NULL },
150 	{ "script",	db_script_cmd,		CS_OWN,	NULL },
151 	{ "scripts",	db_scripts_cmd,		0,	NULL },
152 	{ "unscript",	db_unscript_cmd,	CS_OWN,	NULL },
153 	{ "capture",	db_capture_cmd,		CS_OWN,	NULL },
154 	{ "textdump",	db_textdump_cmd,	CS_OWN, NULL },
155 	{ "findstack",	db_findstack_cmd,	0,	NULL },
156 };
157 struct command_table db_cmd_table = LIST_HEAD_INITIALIZER(db_cmd_table);
158 
159 static struct command	*db_last_command = NULL;
160 
161 /*
162  * if 'ed' style: 'dot' is set at start of last item printed,
163  * and '+' points to next line.
164  * Otherwise: 'dot' points to next item, '..' points to last.
165  */
166 static bool	db_ed_style = true;
167 
168 /*
169  * Utility routine - discard tokens through end-of-line.
170  */
171 void
172 db_skip_to_eol(void)
173 {
174 	int	t;
175 	do {
176 	    t = db_read_token();
177 	} while (t != tEOL);
178 }
179 
180 /*
181  * Results of command search.
182  */
183 #define	CMD_UNIQUE	0
184 #define	CMD_FOUND	1
185 #define	CMD_NONE	2
186 #define	CMD_AMBIGUOUS	3
187 #define	CMD_HELP	4
188 
189 static void	db_cmd_match(char *name, struct command *cmd,
190 		    struct command **cmdp, int *resultp);
191 static void	db_cmd_list(struct command_table *table);
192 static int	db_cmd_search(char *name, struct command_table *table,
193 		    struct command **cmdp);
194 static void	db_command(struct command **last_cmdp,
195 		    struct command_table *cmd_table, int dopager);
196 
197 /*
198  * Initialize the command lists from the static tables.
199  */
200 void
201 db_command_init(void)
202 {
203 #define	N(a)	(sizeof(a) / sizeof(a[0]))
204 	int i;
205 
206 	for (i = 0; i < N(db_cmds); i++)
207 		db_command_register(&db_cmd_table, &db_cmds[i]);
208 	for (i = 0; i < N(db_show_cmds); i++)
209 		db_command_register(&db_show_table, &db_show_cmds[i]);
210 	for (i = 0; i < N(db_show_active_cmds); i++)
211 		db_command_register(&db_show_active_table,
212 		    &db_show_active_cmds[i]);
213 	for (i = 0; i < N(db_show_all_cmds); i++)
214 		db_command_register(&db_show_all_table, &db_show_all_cmds[i]);
215 #undef N
216 }
217 
218 /*
219  * Register a command.
220  */
221 void
222 db_command_register(struct command_table *list, struct command *cmd)
223 {
224 	struct command *c, *last;
225 
226 	last = NULL;
227 	LIST_FOREACH(c, list, next) {
228 		int n = strcmp(cmd->name, c->name);
229 
230 		/* Check that the command is not already present. */
231 		if (n == 0) {
232 			printf("%s: Warning, the command \"%s\" already exists;"
233 			     " ignoring request\n", __func__, cmd->name);
234 			return;
235 		}
236 		if (n < 0) {
237 			/* NB: keep list sorted lexicographically */
238 			LIST_INSERT_BEFORE(c, cmd, next);
239 			return;
240 		}
241 		last = c;
242 	}
243 	if (last == NULL)
244 		LIST_INSERT_HEAD(list, cmd, next);
245 	else
246 		LIST_INSERT_AFTER(last, cmd, next);
247 }
248 
249 /*
250  * Remove a command previously registered with db_command_register.
251  */
252 void
253 db_command_unregister(struct command_table *list, struct command *cmd)
254 {
255 	struct command *c;
256 
257 	LIST_FOREACH(c, list, next) {
258 		if (cmd == c) {
259 			LIST_REMOVE(cmd, next);
260 			return;
261 		}
262 	}
263 	/* NB: intentionally quiet */
264 }
265 
266 /*
267  * Helper function to match a single command.
268  */
269 static void
270 db_cmd_match(char *name, struct command *cmd, struct command **cmdp,
271     int *resultp)
272 {
273 	char *lp, *rp;
274 	int c;
275 
276 	lp = name;
277 	rp = cmd->name;
278 	while ((c = *lp) == *rp) {
279 		if (c == 0) {
280 			/* complete match */
281 			*cmdp = cmd;
282 			*resultp = CMD_UNIQUE;
283 			return;
284 		}
285 		lp++;
286 		rp++;
287 	}
288 	if (c == 0) {
289 		/* end of name, not end of command -
290 		   partial match */
291 		if (*resultp == CMD_FOUND) {
292 			*resultp = CMD_AMBIGUOUS;
293 			/* but keep looking for a full match -
294 			   this lets us match single letters */
295 		} else {
296 			*cmdp = cmd;
297 			*resultp = CMD_FOUND;
298 		}
299 	}
300 }
301 
302 /*
303  * Search for command prefix.
304  */
305 static int
306 db_cmd_search(char *name, struct command_table *table, struct command **cmdp)
307 {
308 	struct command	*cmd;
309 	int		result = CMD_NONE;
310 
311 	LIST_FOREACH(cmd, table, next) {
312 		db_cmd_match(name,cmd,cmdp,&result);
313 		if (result == CMD_UNIQUE)
314 			break;
315 	}
316 
317 	if (result == CMD_NONE) {
318 		/* check for 'help' */
319 		if (name[0] == 'h' && name[1] == 'e'
320 		    && name[2] == 'l' && name[3] == 'p')
321 			result = CMD_HELP;
322 	}
323 	return (result);
324 }
325 
326 static void
327 db_cmd_list(struct command_table *table)
328 {
329 	struct command	*cmd;
330 	int have_subcommands;
331 
332 	have_subcommands = 0;
333 	LIST_FOREACH(cmd, table, next) {
334 		if (cmd->more != NULL)
335 			have_subcommands++;
336 		db_printf("%-16s", cmd->name);
337 		db_end_line(16);
338 	}
339 
340 	if (have_subcommands > 0) {
341 		db_printf("\nThe following have subcommands; append \"help\" "
342 		    "to list (e.g. \"show help\"):\n");
343 		LIST_FOREACH(cmd, table, next) {
344 			if (cmd->more == NULL)
345 				continue;
346 			db_printf("%-16s", cmd->name);
347 			db_end_line(16);
348 		}
349 	}
350 }
351 
352 static void
353 db_command(struct command **last_cmdp, struct command_table *cmd_table,
354     int dopager)
355 {
356 	struct command	*cmd = NULL;
357 	int		t;
358 	char		modif[TOK_STRING_SIZE];
359 	db_expr_t	addr, count;
360 	bool		have_addr = false;
361 	int		result;
362 
363 	t = db_read_token();
364 	if (t == tEOL) {
365 	    /* empty line repeats last command, at 'next' */
366 	    cmd = *last_cmdp;
367 	    addr = (db_expr_t)db_next;
368 	    have_addr = false;
369 	    count = 1;
370 	    modif[0] = '\0';
371 	}
372 	else if (t == tEXCL) {
373 	    db_fncall((db_expr_t)0, (bool)false, (db_expr_t)0, (char *)0);
374 	    return;
375 	}
376 	else if (t != tIDENT) {
377 	    db_printf("Unrecognized input; use \"help\" "
378 	        "to list available commands\n");
379 	    db_flush_lex();
380 	    return;
381 	}
382 	else {
383 	    /*
384 	     * Search for command
385 	     */
386 	    while (cmd_table) {
387 		result = db_cmd_search(db_tok_string,
388 				       cmd_table,
389 				       &cmd);
390 		switch (result) {
391 		    case CMD_NONE:
392 			db_printf("No such command; use \"help\" "
393 			    "to list available commands\n");
394 			db_flush_lex();
395 			return;
396 		    case CMD_AMBIGUOUS:
397 			db_printf("Ambiguous\n");
398 			db_flush_lex();
399 			return;
400 		    case CMD_HELP:
401 			if (cmd_table == &db_cmd_table) {
402 			    db_printf("This is ddb(4), the kernel debugger; "
403 			        "see https://man.FreeBSD.org/ddb/4 for help.\n");
404 			    db_printf("Use \"bt\" for backtrace, \"dump\" for "
405 			        "kernel core dump, \"reset\" to reboot.\n");
406 			    db_printf("Available commands:\n");
407 			}
408 			db_cmd_list(cmd_table);
409 			db_flush_lex();
410 			return;
411 		    default:
412 			break;
413 		}
414 		if ((cmd_table = cmd->more) != NULL) {
415 		    t = db_read_token();
416 		    if (t != tIDENT) {
417 			db_printf("Subcommand required; "
418 			    "available subcommands:\n");
419 			db_cmd_list(cmd_table);
420 			db_flush_lex();
421 			return;
422 		    }
423 		}
424 	    }
425 
426 	    if ((cmd->flag & CS_OWN) == 0) {
427 		/*
428 		 * Standard syntax:
429 		 * command [/modifier] [addr] [,count]
430 		 */
431 		t = db_read_token();
432 		if (t == tSLASH) {
433 		    t = db_read_token();
434 		    if (t != tIDENT) {
435 			db_printf("Bad modifier\n");
436 			db_flush_lex();
437 			return;
438 		    }
439 		    db_strcpy(modif, db_tok_string);
440 		}
441 		else {
442 		    db_unread_token(t);
443 		    modif[0] = '\0';
444 		}
445 
446 		if (db_expression(&addr)) {
447 		    db_dot = (db_addr_t) addr;
448 		    db_last_addr = db_dot;
449 		    have_addr = true;
450 		}
451 		else {
452 		    addr = (db_expr_t) db_dot;
453 		    have_addr = false;
454 		}
455 		t = db_read_token();
456 		if (t == tCOMMA) {
457 		    if (!db_expression(&count)) {
458 			db_printf("Count missing\n");
459 			db_flush_lex();
460 			return;
461 		    }
462 		}
463 		else {
464 		    db_unread_token(t);
465 		    count = -1;
466 		}
467 		if ((cmd->flag & CS_MORE) == 0) {
468 		    db_skip_to_eol();
469 		}
470 	    }
471 	}
472 	*last_cmdp = cmd;
473 	if (cmd != NULL) {
474 	    /*
475 	     * Execute the command.
476 	     */
477 	    if (dopager)
478 		db_enable_pager();
479 	    else
480 		db_disable_pager();
481 	    (*cmd->fcn)(addr, have_addr, count, modif);
482 	    if (dopager)
483 		db_disable_pager();
484 
485 	    if (cmd->flag & CS_SET_DOT) {
486 		/*
487 		 * If command changes dot, set dot to
488 		 * previous address displayed (if 'ed' style).
489 		 */
490 		if (db_ed_style) {
491 		    db_dot = db_prev;
492 		}
493 		else {
494 		    db_dot = db_next;
495 		}
496 	    }
497 	    else {
498 		/*
499 		 * If command does not change dot,
500 		 * set 'next' location to be the same.
501 		 */
502 		db_next = db_dot;
503 	    }
504 	}
505 }
506 
507 /*
508  * At least one non-optional command must be implemented using
509  * DB_COMMAND() so that db_cmd_set gets created.  Here is one.
510  */
511 DB_COMMAND(panic, db_panic)
512 {
513 	db_disable_pager();
514 	panic("from debugger");
515 }
516 
517 void
518 db_command_loop(void)
519 {
520 	/*
521 	 * Initialize 'prev' and 'next' to dot.
522 	 */
523 	db_prev = db_dot;
524 	db_next = db_dot;
525 
526 	db_cmd_loop_done = 0;
527 	while (!db_cmd_loop_done) {
528 	    if (db_print_position() != 0)
529 		db_printf("\n");
530 
531 	    db_printf("db> ");
532 	    (void) db_read_line();
533 
534 	    db_command(&db_last_command, &db_cmd_table, /* dopager */ 1);
535 	}
536 }
537 
538 /*
539  * Execute a command on behalf of a script.  The caller is responsible for
540  * making sure that the command string is < DB_MAXLINE or it will be
541  * truncated.
542  *
543  * XXXRW: Runs by injecting faked input into DDB input stream; it would be
544  * nicer to use an alternative approach that didn't mess with the previous
545  * command buffer.
546  */
547 void
548 db_command_script(const char *command)
549 {
550 	db_prev = db_next = db_dot;
551 	db_inject_line(command);
552 	db_command(&db_last_command, &db_cmd_table, /* dopager */ 0);
553 }
554 
555 void
556 db_error(const char *s)
557 {
558 	if (s)
559 	    db_printf("%s", s);
560 	db_flush_lex();
561 	kdb_reenter_silent();
562 }
563 
564 static void
565 db_dump(db_expr_t dummy, bool dummy2, db_expr_t dummy3, char *dummy4)
566 {
567 	int error;
568 
569 	if (textdump_pending) {
570 		db_printf("textdump_pending set.\n"
571 		    "run \"textdump unset\" first or \"textdump dump\" for a textdump.\n");
572 		return;
573 	}
574 	error = doadump(false);
575 	if (error) {
576 		db_printf("Cannot dump: ");
577 		switch (error) {
578 		case EBUSY:
579 			db_printf("debugger got invoked while dumping.\n");
580 			break;
581 		case ENXIO:
582 			db_printf("no dump device specified.\n");
583 			break;
584 		default:
585 			db_printf("unknown error (error=%d).\n", error);
586 			break;
587 		}
588 	}
589 }
590 
591 /*
592  * Call random function:
593  * !expr(arg,arg,arg)
594  */
595 
596 /* The generic implementation supports a maximum of 10 arguments. */
597 typedef db_expr_t __db_f(db_expr_t, db_expr_t, db_expr_t, db_expr_t,
598     db_expr_t, db_expr_t, db_expr_t, db_expr_t, db_expr_t, db_expr_t);
599 
600 static __inline int
601 db_fncall_generic(db_expr_t addr, db_expr_t *rv, int nargs, db_expr_t args[])
602 {
603 	__db_f *f = (__db_f *)addr;
604 
605 	if (nargs > 10) {
606 		db_printf("Too many arguments (max 10)\n");
607 		return (0);
608 	}
609 	*rv = (*f)(args[0], args[1], args[2], args[3], args[4], args[5],
610 	    args[6], args[7], args[8], args[9]);
611 	return (1);
612 }
613 
614 static void
615 db_fncall(db_expr_t dummy1, bool dummy2, db_expr_t dummy3, char *dummy4)
616 {
617 	db_expr_t	fn_addr;
618 	db_expr_t	args[DB_MAXARGS];
619 	int		nargs = 0;
620 	db_expr_t	retval;
621 	int		t;
622 
623 	if (!db_expression(&fn_addr)) {
624 	    db_printf("Bad function\n");
625 	    db_flush_lex();
626 	    return;
627 	}
628 
629 	t = db_read_token();
630 	if (t == tLPAREN) {
631 	    if (db_expression(&args[0])) {
632 		nargs++;
633 		while ((t = db_read_token()) == tCOMMA) {
634 		    if (nargs == DB_MAXARGS) {
635 			db_printf("Too many arguments (max %d)\n", DB_MAXARGS);
636 			db_flush_lex();
637 			return;
638 		    }
639 		    if (!db_expression(&args[nargs])) {
640 			db_printf("Argument missing\n");
641 			db_flush_lex();
642 			return;
643 		    }
644 		    nargs++;
645 		}
646 		db_unread_token(t);
647 	    }
648 	    if (db_read_token() != tRPAREN) {
649 	        db_printf("Mismatched parens\n");
650 		db_flush_lex();
651 		return;
652 	    }
653 	}
654 	db_skip_to_eol();
655 	db_disable_pager();
656 
657 	if (DB_CALL(fn_addr, &retval, nargs, args))
658 		db_printf("= %#lr\n", (long)retval);
659 }
660 
661 static void
662 db_halt(db_expr_t dummy, bool dummy2, db_expr_t dummy3, char *dummy4)
663 {
664 
665 	cpu_halt();
666 }
667 
668 static void
669 db_kill(db_expr_t dummy1, bool dummy2, db_expr_t dummy3, char *dummy4)
670 {
671 	db_expr_t old_radix, pid, sig;
672 	struct proc *p;
673 
674 #define	DB_ERROR(f)	do { db_printf f; db_flush_lex(); goto out; } while (0)
675 
676 	/*
677 	 * PIDs and signal numbers are typically represented in base
678 	 * 10, so make that the default here.  It can, of course, be
679 	 * overridden by specifying a prefix.
680 	 */
681 	old_radix = db_radix;
682 	db_radix = 10;
683 	/* Retrieve arguments. */
684 	if (!db_expression(&sig))
685 		DB_ERROR(("Missing signal number\n"));
686 	if (!db_expression(&pid))
687 		DB_ERROR(("Missing process ID\n"));
688 	db_skip_to_eol();
689 	if (!_SIG_VALID(sig))
690 		DB_ERROR(("Signal number out of range\n"));
691 
692 	/*
693 	 * Find the process in question.  allproc_lock is not needed
694 	 * since we're in DDB.
695 	 */
696 	/* sx_slock(&allproc_lock); */
697 	FOREACH_PROC_IN_SYSTEM(p)
698 	    if (p->p_pid == pid)
699 		    break;
700 	/* sx_sunlock(&allproc_lock); */
701 	if (p == NULL)
702 		DB_ERROR(("Can't find process with pid %ld\n", (long) pid));
703 
704 	/* If it's already locked, bail; otherwise, do the deed. */
705 	if (PROC_TRYLOCK(p) == 0)
706 		DB_ERROR(("Can't lock process with pid %ld\n", (long) pid));
707 	else {
708 		pksignal(p, sig, NULL);
709 		PROC_UNLOCK(p);
710 	}
711 
712 out:
713 	db_radix = old_radix;
714 #undef DB_ERROR
715 }
716 
717 /*
718  * Reboot.  In case there is an additional argument, take it as delay in
719  * seconds.  Default to 15s if we cannot parse it and make sure we will
720  * never wait longer than 1 week.  Some code is similar to
721  * kern_shutdown.c:shutdown_panic().
722  */
723 #ifndef	DB_RESET_MAXDELAY
724 #define	DB_RESET_MAXDELAY	(3600 * 24 * 7)
725 #endif
726 
727 static void
728 db_reset(db_expr_t addr, bool have_addr, db_expr_t count __unused,
729     char *modif __unused)
730 {
731 	int delay, loop;
732 
733 	if (have_addr) {
734 		delay = (int)db_hex2dec(addr);
735 
736 		/* If we parse to fail, use 15s. */
737 		if (delay == -1)
738 			delay = 15;
739 
740 		/* Cap at one week. */
741 		if ((uintmax_t)delay > (uintmax_t)DB_RESET_MAXDELAY)
742 			delay = DB_RESET_MAXDELAY;
743 
744 		db_printf("Automatic reboot in %d seconds - "
745 		    "press a key on the console to abort\n", delay);
746 		for (loop = delay * 10; loop > 0; --loop) {
747 			DELAY(1000 * 100); /* 1/10th second */
748 			/* Did user type a key? */
749 			if (cncheckc() != -1)
750 				return;
751 		}
752 	}
753 
754 	cpu_reset();
755 }
756 
757 static void
758 db_watchdog(db_expr_t dummy1, bool dummy2, db_expr_t dummy3, char *dummy4)
759 {
760 	db_expr_t old_radix, tout;
761 	int err, i;
762 
763 	old_radix = db_radix;
764 	db_radix = 10;
765 	err = db_expression(&tout);
766 	db_skip_to_eol();
767 	db_radix = old_radix;
768 
769 	/* If no argument is provided the watchdog will just be disabled. */
770 	if (err == 0) {
771 		db_printf("No argument provided, disabling watchdog\n");
772 		tout = 0;
773 	} else if ((tout & WD_INTERVAL) == WD_TO_NEVER) {
774 		db_error("Out of range watchdog interval\n");
775 		return;
776 	}
777 	EVENTHANDLER_INVOKE(watchdog_list, tout, &i);
778 }
779 
780 static void
781 db_gdb(db_expr_t dummy1, bool dummy2, db_expr_t dummy3, char *dummy4)
782 {
783 
784 	if (kdb_dbbe_select("gdb") != 0) {
785 		db_printf("The remote GDB backend could not be selected.\n");
786 		return;
787 	}
788 	/*
789 	 * Mark that we are done in the debugger.  kdb_trap()
790 	 * should re-enter with the new backend.
791 	 */
792 	db_cmd_loop_done = 1;
793 	db_printf("(ctrl-c will return control to ddb)\n");
794 }
795 
796 static void
797 db_stack_trace(db_expr_t tid, bool hastid, db_expr_t count, char *modif)
798 {
799 	struct thread *td;
800 	db_expr_t radix;
801 	pid_t pid;
802 	int t;
803 
804 	/*
805 	 * We parse our own arguments. We don't like the default radix.
806 	 */
807 	radix = db_radix;
808 	db_radix = 10;
809 	hastid = db_expression(&tid);
810 	t = db_read_token();
811 	if (t == tCOMMA) {
812 		if (!db_expression(&count)) {
813 			db_printf("Count missing\n");
814 			db_flush_lex();
815 			db_radix = radix;
816 			return;
817 		}
818 	} else {
819 		db_unread_token(t);
820 		count = -1;
821 	}
822 	db_skip_to_eol();
823 	db_radix = radix;
824 
825 	if (hastid) {
826 		td = kdb_thr_lookup((lwpid_t)tid);
827 		if (td == NULL)
828 			td = kdb_thr_from_pid((pid_t)tid);
829 		if (td == NULL) {
830 			db_printf("Thread %d not found\n", (int)tid);
831 			return;
832 		}
833 	} else
834 		td = kdb_thread;
835 	if (td->td_proc != NULL)
836 		pid = td->td_proc->p_pid;
837 	else
838 		pid = -1;
839 	db_printf("Tracing pid %d tid %ld td %p\n", pid, (long)td->td_tid, td);
840 	db_trace_thread(td, count);
841 }
842 
843 static void
844 _db_stack_trace_all(bool active_only)
845 {
846 	struct proc *p;
847 	struct thread *td;
848 	jmp_buf jb;
849 	void *prev_jb;
850 
851 	FOREACH_PROC_IN_SYSTEM(p) {
852 		prev_jb = kdb_jmpbuf(jb);
853 		if (setjmp(jb) == 0) {
854 			FOREACH_THREAD_IN_PROC(p, td) {
855 				if (td->td_state == TDS_RUNNING)
856 					db_printf("\nTracing command %s pid %d"
857 					    " tid %ld td %p (CPU %d)\n",
858 					    p->p_comm, p->p_pid,
859 					    (long)td->td_tid, td,
860 					    td->td_oncpu);
861 				else if (active_only)
862 					continue;
863 				else
864 					db_printf("\nTracing command %s pid %d"
865 					    " tid %ld td %p\n", p->p_comm,
866 					    p->p_pid, (long)td->td_tid, td);
867 				db_trace_thread(td, -1);
868 				if (db_pager_quit) {
869 					kdb_jmpbuf(prev_jb);
870 					return;
871 				}
872 			}
873 		}
874 		kdb_jmpbuf(prev_jb);
875 	}
876 }
877 
878 static void
879 db_stack_trace_active(db_expr_t dummy, bool dummy2, db_expr_t dummy3,
880     char *dummy4)
881 {
882 
883 	_db_stack_trace_all(true);
884 }
885 
886 static void
887 db_stack_trace_all(db_expr_t dummy, bool dummy2, db_expr_t dummy3,
888     char *dummy4)
889 {
890 
891 	_db_stack_trace_all(false);
892 }
893 
894 /*
895  * Take the parsed expression value from the command line that was parsed
896  * as a hexadecimal value and convert it as if the expression was parsed
897  * as a decimal value.  Returns -1 if the expression was not a valid
898  * decimal value.
899  */
900 db_expr_t
901 db_hex2dec(db_expr_t expr)
902 {
903 	uintptr_t x, y;
904 	db_expr_t val;
905 
906 	y = 1;
907 	val = 0;
908 	x = expr;
909 	while (x != 0) {
910 		if (x % 16 > 9)
911 			return (-1);
912 		val += (x % 16) * (y);
913 		x >>= 4;
914 		y *= 10;
915 	}
916 	return (val);
917 }
918