xref: /freebsd/sys/ddb/db_command.c (revision f61e92ca5a23450bc28169bbdd71d7674df98c19)
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/eventhandler.h>
41 #include <sys/linker_set.h>
42 #include <sys/lock.h>
43 #include <sys/kdb.h>
44 #include <sys/mutex.h>
45 #include <sys/proc.h>
46 #include <sys/reboot.h>
47 #include <sys/signalvar.h>
48 #include <sys/systm.h>
49 #include <sys/cons.h>
50 #include <sys/conf.h>
51 #include <sys/watchdog.h>
52 #include <sys/kernel.h>
53 
54 #include <ddb/ddb.h>
55 #include <ddb/db_command.h>
56 #include <ddb/db_lex.h>
57 #include <ddb/db_output.h>
58 
59 #include <machine/cpu.h>
60 #include <machine/setjmp.h>
61 
62 /*
63  * Exported global variables
64  */
65 int		db_cmd_loop_done;
66 db_addr_t	db_dot;
67 db_addr_t	db_last_addr;
68 db_addr_t	db_prev;
69 db_addr_t	db_next;
70 
71 static db_cmdfcn_t	db_dump;
72 static db_cmdfcn_t	db_fncall;
73 static db_cmdfcn_t	db_gdb;
74 static db_cmdfcn_t	db_halt;
75 static db_cmdfcn_t	db_kill;
76 static db_cmdfcn_t	db_reset;
77 static db_cmdfcn_t	db_stack_trace;
78 static db_cmdfcn_t	db_stack_trace_active;
79 static db_cmdfcn_t	db_stack_trace_all;
80 static db_cmdfcn_t	db_watchdog;
81 
82 /*
83  * 'show' commands
84  */
85 
86 static struct command db_show_active_cmds[] = {
87 	{ "trace",	db_stack_trace_active,	0,	NULL },
88 };
89 struct command_table db_show_active_table =
90     LIST_HEAD_INITIALIZER(db_show_active_table);
91 
92 static struct command db_show_all_cmds[] = {
93 	{ "trace",	db_stack_trace_all,	0,	NULL },
94 };
95 struct command_table db_show_all_table =
96     LIST_HEAD_INITIALIZER(db_show_all_table);
97 
98 static struct command db_show_cmds[] = {
99 	{ "active",	0,			0,	&db_show_active_table },
100 	{ "all",	0,			0,	&db_show_all_table },
101 	{ "registers",	db_show_regs,		0,	NULL },
102 	{ "breaks",	db_listbreak_cmd, 	0,	NULL },
103 	{ "threads",	db_show_threads,	0,	NULL },
104 };
105 struct command_table db_show_table = LIST_HEAD_INITIALIZER(db_show_table);
106 
107 static struct command db_cmds[] = {
108 	{ "print",	db_print_cmd,		0,	NULL },
109 	{ "p",		db_print_cmd,		0,	NULL },
110 	{ "examine",	db_examine_cmd,		CS_SET_DOT, NULL },
111 	{ "x",		db_examine_cmd,		CS_SET_DOT, NULL },
112 	{ "search",	db_search_cmd,		CS_OWN|CS_SET_DOT, NULL },
113 	{ "set",	db_set_cmd,		CS_OWN,	NULL },
114 	{ "write",	db_write_cmd,		CS_MORE|CS_SET_DOT, NULL },
115 	{ "w",		db_write_cmd,		CS_MORE|CS_SET_DOT, NULL },
116 	{ "delete",	db_delete_cmd,		0,	NULL },
117 	{ "d",		db_delete_cmd,		0,	NULL },
118 	{ "dump",	db_dump,		0,	NULL },
119 	{ "break",	db_breakpoint_cmd,	0,	NULL },
120 	{ "b",		db_breakpoint_cmd,	0,	NULL },
121 	{ "dwatch",	db_deletewatch_cmd,	0,	NULL },
122 	{ "watch",	db_watchpoint_cmd,	CS_MORE,NULL },
123 	{ "dhwatch",	db_deletehwatch_cmd,	0,      NULL },
124 	{ "hwatch",	db_hwatchpoint_cmd,	0,      NULL },
125 	{ "step",	db_single_step_cmd,	0,	NULL },
126 	{ "s",		db_single_step_cmd,	0,	NULL },
127 	{ "continue",	db_continue_cmd,	0,	NULL },
128 	{ "c",		db_continue_cmd,	0,	NULL },
129 	{ "until",	db_trace_until_call_cmd,0,	NULL },
130 	{ "next",	db_trace_until_matching_cmd,0,	NULL },
131 	{ "match",	db_trace_until_matching_cmd,0,	NULL },
132 	{ "trace",	db_stack_trace,		CS_OWN,	NULL },
133 	{ "t",		db_stack_trace,		CS_OWN,	NULL },
134 	/* XXX alias for active trace */
135 	{ "acttrace",	db_stack_trace_active,	0,	NULL },
136 	/* XXX alias for all trace */
137 	{ "alltrace",	db_stack_trace_all,	0,	NULL },
138 	{ "where",	db_stack_trace,		CS_OWN,	NULL },
139 	{ "bt",		db_stack_trace,		CS_OWN,	NULL },
140 	{ "call",	db_fncall,		CS_OWN,	NULL },
141 	{ "show",	0,			0,	&db_show_table },
142 	{ "ps",		db_ps,			0,	NULL },
143 	{ "gdb",	db_gdb,			0,	NULL },
144 	{ "halt",	db_halt,		0,	NULL },
145 	{ "reboot",	db_reset,		0,	NULL },
146 	{ "reset",	db_reset,		0,	NULL },
147 	{ "kill",	db_kill,		CS_OWN,	NULL },
148 	{ "watchdog",	db_watchdog,		CS_OWN,	NULL },
149 	{ "thread",	db_set_thread,		0,	NULL },
150 	{ "run",	db_run_cmd,		CS_OWN,	NULL },
151 	{ "script",	db_script_cmd,		CS_OWN,	NULL },
152 	{ "scripts",	db_scripts_cmd,		0,	NULL },
153 	{ "unscript",	db_unscript_cmd,	CS_OWN,	NULL },
154 	{ "capture",	db_capture_cmd,		CS_OWN,	NULL },
155 	{ "textdump",	db_textdump_cmd,	CS_OWN, NULL },
156 	{ "findstack",	db_findstack_cmd,	0,	NULL },
157 };
158 struct command_table db_cmd_table = LIST_HEAD_INITIALIZER(db_cmd_table);
159 
160 static struct command	*db_last_command = NULL;
161 
162 /*
163  * if 'ed' style: 'dot' is set at start of last item printed,
164  * and '+' points to next line.
165  * Otherwise: 'dot' points to next item, '..' points to last.
166  */
167 static bool	db_ed_style = true;
168 
169 /*
170  * Utility routine - discard tokens through end-of-line.
171  */
172 void
173 db_skip_to_eol(void)
174 {
175 	int	t;
176 	do {
177 	    t = db_read_token();
178 	} while (t != tEOL);
179 }
180 
181 /*
182  * Results of command search.
183  */
184 #define	CMD_UNIQUE	0
185 #define	CMD_FOUND	1
186 #define	CMD_NONE	2
187 #define	CMD_AMBIGUOUS	3
188 #define	CMD_HELP	4
189 
190 static void	db_cmd_match(char *name, struct command *cmd,
191 		    struct command **cmdp, int *resultp);
192 static void	db_cmd_list(struct command_table *table);
193 static int	db_cmd_search(char *name, struct command_table *table,
194 		    struct command **cmdp);
195 static void	db_command(struct command **last_cmdp,
196 		    struct command_table *cmd_table, int dopager);
197 
198 /*
199  * Initialize the command lists from the static tables.
200  */
201 void
202 db_command_init(void)
203 {
204 #define	N(a)	(sizeof(a) / sizeof(a[0]))
205 	int i;
206 
207 	for (i = 0; i < N(db_cmds); i++)
208 		db_command_register(&db_cmd_table, &db_cmds[i]);
209 	for (i = 0; i < N(db_show_cmds); i++)
210 		db_command_register(&db_show_table, &db_show_cmds[i]);
211 	for (i = 0; i < N(db_show_active_cmds); i++)
212 		db_command_register(&db_show_active_table,
213 		    &db_show_active_cmds[i]);
214 	for (i = 0; i < N(db_show_all_cmds); i++)
215 		db_command_register(&db_show_all_table, &db_show_all_cmds[i]);
216 #undef N
217 }
218 
219 /*
220  * Register a command.
221  */
222 void
223 db_command_register(struct command_table *list, struct command *cmd)
224 {
225 	struct command *c, *last;
226 
227 	last = NULL;
228 	LIST_FOREACH(c, list, next) {
229 		int n = strcmp(cmd->name, c->name);
230 
231 		/* Check that the command is not already present. */
232 		if (n == 0) {
233 			printf("%s: Warning, the command \"%s\" already exists;"
234 			     " ignoring request\n", __func__, cmd->name);
235 			return;
236 		}
237 		if (n < 0) {
238 			/* NB: keep list sorted lexicographically */
239 			LIST_INSERT_BEFORE(c, cmd, next);
240 			return;
241 		}
242 		last = c;
243 	}
244 	if (last == NULL)
245 		LIST_INSERT_HEAD(list, cmd, next);
246 	else
247 		LIST_INSERT_AFTER(last, cmd, next);
248 }
249 
250 /*
251  * Remove a command previously registered with db_command_register.
252  */
253 void
254 db_command_unregister(struct command_table *list, struct command *cmd)
255 {
256 	struct command *c;
257 
258 	LIST_FOREACH(c, list, next) {
259 		if (cmd == c) {
260 			LIST_REMOVE(cmd, next);
261 			return;
262 		}
263 	}
264 	/* NB: intentionally quiet */
265 }
266 
267 /*
268  * Helper function to match a single command.
269  */
270 static void
271 db_cmd_match(char *name, struct command *cmd, struct command **cmdp,
272     int *resultp)
273 {
274 	char *lp, *rp;
275 	int c;
276 
277 	lp = name;
278 	rp = cmd->name;
279 	while ((c = *lp) == *rp) {
280 		if (c == 0) {
281 			/* complete match */
282 			*cmdp = cmd;
283 			*resultp = CMD_UNIQUE;
284 			return;
285 		}
286 		lp++;
287 		rp++;
288 	}
289 	if (c == 0) {
290 		/* end of name, not end of command -
291 		   partial match */
292 		if (*resultp == CMD_FOUND) {
293 			*resultp = CMD_AMBIGUOUS;
294 			/* but keep looking for a full match -
295 			   this lets us match single letters */
296 		} else {
297 			*cmdp = cmd;
298 			*resultp = CMD_FOUND;
299 		}
300 	}
301 }
302 
303 /*
304  * Search for command prefix.
305  */
306 static int
307 db_cmd_search(char *name, struct command_table *table, struct command **cmdp)
308 {
309 	struct command	*cmd;
310 	int		result = CMD_NONE;
311 
312 	LIST_FOREACH(cmd, table, next) {
313 		db_cmd_match(name,cmd,cmdp,&result);
314 		if (result == CMD_UNIQUE)
315 			break;
316 	}
317 
318 	if (result == CMD_NONE) {
319 		/* check for 'help' */
320 		if (name[0] == 'h' && name[1] == 'e'
321 		    && name[2] == 'l' && name[3] == 'p')
322 			result = CMD_HELP;
323 	}
324 	return (result);
325 }
326 
327 static void
328 db_cmd_list(struct command_table *table)
329 {
330 	struct command	*cmd;
331 	int have_subcommands;
332 
333 	have_subcommands = 0;
334 	LIST_FOREACH(cmd, table, next) {
335 		if (cmd->more != NULL)
336 			have_subcommands++;
337 		db_printf("%-16s", cmd->name);
338 		db_end_line(16);
339 	}
340 
341 	if (have_subcommands > 0) {
342 		db_printf("\nThe following have subcommands; append \"help\" "
343 		    "to list (e.g. \"show help\"):\n");
344 		LIST_FOREACH(cmd, table, next) {
345 			if (cmd->more == NULL)
346 				continue;
347 			db_printf("%-16s", cmd->name);
348 			db_end_line(16);
349 		}
350 	}
351 }
352 
353 static void
354 db_command(struct command **last_cmdp, struct command_table *cmd_table,
355     int dopager)
356 {
357 	struct command	*cmd = NULL;
358 	int		t;
359 	char		modif[TOK_STRING_SIZE];
360 	db_expr_t	addr, count;
361 	bool		have_addr = false;
362 	int		result;
363 
364 	t = db_read_token();
365 	if (t == tEOL) {
366 	    /* empty line repeats last command, at 'next' */
367 	    cmd = *last_cmdp;
368 	    addr = (db_expr_t)db_next;
369 	    have_addr = false;
370 	    count = 1;
371 	    modif[0] = '\0';
372 	}
373 	else if (t == tEXCL) {
374 	    db_fncall((db_expr_t)0, (bool)false, (db_expr_t)0, (char *)0);
375 	    return;
376 	}
377 	else if (t != tIDENT) {
378 	    db_printf("Unrecognized input; use \"help\" "
379 	        "to list available commands\n");
380 	    db_flush_lex();
381 	    return;
382 	}
383 	else {
384 	    /*
385 	     * Search for command
386 	     */
387 	    while (cmd_table) {
388 		result = db_cmd_search(db_tok_string,
389 				       cmd_table,
390 				       &cmd);
391 		switch (result) {
392 		    case CMD_NONE:
393 			db_printf("No such command; use \"help\" "
394 			    "to list available commands\n");
395 			db_flush_lex();
396 			return;
397 		    case CMD_AMBIGUOUS:
398 			db_printf("Ambiguous\n");
399 			db_flush_lex();
400 			return;
401 		    case CMD_HELP:
402 			if (cmd_table == &db_cmd_table) {
403 			    db_printf("This is ddb(4), the kernel debugger; "
404 			        "see https://man.FreeBSD.org/ddb/4 for help.\n");
405 			    db_printf("Use \"bt\" for backtrace, \"dump\" for "
406 			        "kernel core dump, \"reset\" to reboot.\n");
407 			    db_printf("Available commands:\n");
408 			}
409 			db_cmd_list(cmd_table);
410 			db_flush_lex();
411 			return;
412 		    default:
413 			break;
414 		}
415 		if ((cmd_table = cmd->more) != NULL) {
416 		    t = db_read_token();
417 		    if (t != tIDENT) {
418 			db_printf("Subcommand required; "
419 			    "available subcommands:\n");
420 			db_cmd_list(cmd_table);
421 			db_flush_lex();
422 			return;
423 		    }
424 		}
425 	    }
426 
427 	    if ((cmd->flag & CS_OWN) == 0) {
428 		/*
429 		 * Standard syntax:
430 		 * command [/modifier] [addr] [,count]
431 		 */
432 		t = db_read_token();
433 		if (t == tSLASH) {
434 		    t = db_read_token();
435 		    if (t != tIDENT) {
436 			db_printf("Bad modifier\n");
437 			db_flush_lex();
438 			return;
439 		    }
440 		    db_strcpy(modif, db_tok_string);
441 		}
442 		else {
443 		    db_unread_token(t);
444 		    modif[0] = '\0';
445 		}
446 
447 		if (db_expression(&addr)) {
448 		    db_dot = (db_addr_t) addr;
449 		    db_last_addr = db_dot;
450 		    have_addr = true;
451 		}
452 		else {
453 		    addr = (db_expr_t) db_dot;
454 		    have_addr = false;
455 		}
456 		t = db_read_token();
457 		if (t == tCOMMA) {
458 		    if (!db_expression(&count)) {
459 			db_printf("Count missing\n");
460 			db_flush_lex();
461 			return;
462 		    }
463 		}
464 		else {
465 		    db_unread_token(t);
466 		    count = -1;
467 		}
468 		if ((cmd->flag & CS_MORE) == 0) {
469 		    db_skip_to_eol();
470 		}
471 	    }
472 	}
473 	*last_cmdp = cmd;
474 	if (cmd != NULL) {
475 	    /*
476 	     * Execute the command.
477 	     */
478 	    if (dopager)
479 		db_enable_pager();
480 	    else
481 		db_disable_pager();
482 	    (*cmd->fcn)(addr, have_addr, count, modif);
483 	    if (dopager)
484 		db_disable_pager();
485 
486 	    if (cmd->flag & CS_SET_DOT) {
487 		/*
488 		 * If command changes dot, set dot to
489 		 * previous address displayed (if 'ed' style).
490 		 */
491 		if (db_ed_style) {
492 		    db_dot = db_prev;
493 		}
494 		else {
495 		    db_dot = db_next;
496 		}
497 	    }
498 	    else {
499 		/*
500 		 * If command does not change dot,
501 		 * set 'next' location to be the same.
502 		 */
503 		db_next = db_dot;
504 	    }
505 	}
506 }
507 
508 /*
509  * At least one non-optional command must be implemented using
510  * DB_COMMAND() so that db_cmd_set gets created.  Here is one.
511  */
512 DB_COMMAND(panic, db_panic)
513 {
514 	db_disable_pager();
515 	panic("from debugger");
516 }
517 
518 void
519 db_command_loop(void)
520 {
521 	/*
522 	 * Initialize 'prev' and 'next' to dot.
523 	 */
524 	db_prev = db_dot;
525 	db_next = db_dot;
526 
527 	db_cmd_loop_done = 0;
528 	while (!db_cmd_loop_done) {
529 	    if (db_print_position() != 0)
530 		db_printf("\n");
531 
532 	    db_printf("db> ");
533 	    (void) db_read_line();
534 
535 	    db_command(&db_last_command, &db_cmd_table, /* dopager */ 1);
536 	}
537 }
538 
539 /*
540  * Execute a command on behalf of a script.  The caller is responsible for
541  * making sure that the command string is < DB_MAXLINE or it will be
542  * truncated.
543  *
544  * XXXRW: Runs by injecting faked input into DDB input stream; it would be
545  * nicer to use an alternative approach that didn't mess with the previous
546  * command buffer.
547  */
548 void
549 db_command_script(const char *command)
550 {
551 	db_prev = db_next = db_dot;
552 	db_inject_line(command);
553 	db_command(&db_last_command, &db_cmd_table, /* dopager */ 0);
554 }
555 
556 void
557 db_error(const char *s)
558 {
559 	if (s)
560 	    db_printf("%s", s);
561 	db_flush_lex();
562 	kdb_reenter_silent();
563 }
564 
565 static void
566 db_dump(db_expr_t dummy, bool dummy2, db_expr_t dummy3, char *dummy4)
567 {
568 	int error;
569 
570 	if (textdump_pending) {
571 		db_printf("textdump_pending set.\n"
572 		    "run \"textdump unset\" first or \"textdump dump\" for a textdump.\n");
573 		return;
574 	}
575 	error = doadump(false);
576 	if (error) {
577 		db_printf("Cannot dump: ");
578 		switch (error) {
579 		case EBUSY:
580 			db_printf("debugger got invoked while dumping.\n");
581 			break;
582 		case ENXIO:
583 			db_printf("no dump device specified.\n");
584 			break;
585 		default:
586 			db_printf("unknown error (error=%d).\n", error);
587 			break;
588 		}
589 	}
590 }
591 
592 /*
593  * Call random function:
594  * !expr(arg,arg,arg)
595  */
596 
597 /* The generic implementation supports a maximum of 10 arguments. */
598 typedef db_expr_t __db_f(db_expr_t, db_expr_t, db_expr_t, db_expr_t,
599     db_expr_t, db_expr_t, db_expr_t, db_expr_t, db_expr_t, db_expr_t);
600 
601 static __inline int
602 db_fncall_generic(db_expr_t addr, db_expr_t *rv, int nargs, db_expr_t args[])
603 {
604 	__db_f *f = (__db_f *)addr;
605 
606 	if (nargs > 10) {
607 		db_printf("Too many arguments (max 10)\n");
608 		return (0);
609 	}
610 	*rv = (*f)(args[0], args[1], args[2], args[3], args[4], args[5],
611 	    args[6], args[7], args[8], args[9]);
612 	return (1);
613 }
614 
615 static void
616 db_fncall(db_expr_t dummy1, bool dummy2, db_expr_t dummy3, char *dummy4)
617 {
618 	db_expr_t	fn_addr;
619 	db_expr_t	args[DB_MAXARGS];
620 	int		nargs = 0;
621 	db_expr_t	retval;
622 	int		t;
623 
624 	if (!db_expression(&fn_addr)) {
625 	    db_printf("Bad function\n");
626 	    db_flush_lex();
627 	    return;
628 	}
629 
630 	t = db_read_token();
631 	if (t == tLPAREN) {
632 	    if (db_expression(&args[0])) {
633 		nargs++;
634 		while ((t = db_read_token()) == tCOMMA) {
635 		    if (nargs == DB_MAXARGS) {
636 			db_printf("Too many arguments (max %d)\n", DB_MAXARGS);
637 			db_flush_lex();
638 			return;
639 		    }
640 		    if (!db_expression(&args[nargs])) {
641 			db_printf("Argument missing\n");
642 			db_flush_lex();
643 			return;
644 		    }
645 		    nargs++;
646 		}
647 		db_unread_token(t);
648 	    }
649 	    if (db_read_token() != tRPAREN) {
650 	        db_printf("Mismatched parens\n");
651 		db_flush_lex();
652 		return;
653 	    }
654 	}
655 	db_skip_to_eol();
656 	db_disable_pager();
657 
658 	if (DB_CALL(fn_addr, &retval, nargs, args))
659 		db_printf("= %#lr\n", (long)retval);
660 }
661 
662 static void
663 db_halt(db_expr_t dummy, bool dummy2, db_expr_t dummy3, char *dummy4)
664 {
665 
666 	cpu_halt();
667 }
668 
669 static void
670 db_kill(db_expr_t dummy1, bool dummy2, db_expr_t dummy3, char *dummy4)
671 {
672 	db_expr_t old_radix, pid, sig;
673 	struct proc *p;
674 
675 #define	DB_ERROR(f)	do { db_printf f; db_flush_lex(); goto out; } while (0)
676 
677 	/*
678 	 * PIDs and signal numbers are typically represented in base
679 	 * 10, so make that the default here.  It can, of course, be
680 	 * overridden by specifying a prefix.
681 	 */
682 	old_radix = db_radix;
683 	db_radix = 10;
684 	/* Retrieve arguments. */
685 	if (!db_expression(&sig))
686 		DB_ERROR(("Missing signal number\n"));
687 	if (!db_expression(&pid))
688 		DB_ERROR(("Missing process ID\n"));
689 	db_skip_to_eol();
690 	if (!_SIG_VALID(sig))
691 		DB_ERROR(("Signal number out of range\n"));
692 
693 	/*
694 	 * Find the process in question.  allproc_lock is not needed
695 	 * since we're in DDB.
696 	 */
697 	/* sx_slock(&allproc_lock); */
698 	FOREACH_PROC_IN_SYSTEM(p)
699 	    if (p->p_pid == pid)
700 		    break;
701 	/* sx_sunlock(&allproc_lock); */
702 	if (p == NULL)
703 		DB_ERROR(("Can't find process with pid %ld\n", (long) pid));
704 
705 	/* If it's already locked, bail; otherwise, do the deed. */
706 	if (PROC_TRYLOCK(p) == 0)
707 		DB_ERROR(("Can't lock process with pid %ld\n", (long) pid));
708 	else {
709 		pksignal(p, sig, NULL);
710 		PROC_UNLOCK(p);
711 	}
712 
713 out:
714 	db_radix = old_radix;
715 #undef DB_ERROR
716 }
717 
718 /*
719  * Reboot.  In case there is an additional argument, take it as delay in
720  * seconds.  Default to 15s if we cannot parse it and make sure we will
721  * never wait longer than 1 week.  Some code is similar to
722  * kern_shutdown.c:shutdown_panic().
723  */
724 #ifndef	DB_RESET_MAXDELAY
725 #define	DB_RESET_MAXDELAY	(3600 * 24 * 7)
726 #endif
727 
728 static void
729 db_reset(db_expr_t addr, bool have_addr, db_expr_t count __unused,
730     char *modif __unused)
731 {
732 	int delay, loop;
733 
734 	if (have_addr) {
735 		delay = (int)db_hex2dec(addr);
736 
737 		/* If we parse to fail, use 15s. */
738 		if (delay == -1)
739 			delay = 15;
740 
741 		/* Cap at one week. */
742 		if ((uintmax_t)delay > (uintmax_t)DB_RESET_MAXDELAY)
743 			delay = DB_RESET_MAXDELAY;
744 
745 		db_printf("Automatic reboot in %d seconds - "
746 		    "press a key on the console to abort\n", delay);
747 		for (loop = delay * 10; loop > 0; --loop) {
748 			DELAY(1000 * 100); /* 1/10th second */
749 			/* Did user type a key? */
750 			if (cncheckc() != -1)
751 				return;
752 		}
753 	}
754 
755 	cpu_reset();
756 }
757 
758 static void
759 db_watchdog(db_expr_t dummy1, bool dummy2, db_expr_t dummy3, char *dummy4)
760 {
761 	db_expr_t old_radix, tout;
762 	int err, i;
763 
764 	old_radix = db_radix;
765 	db_radix = 10;
766 	err = db_expression(&tout);
767 	db_skip_to_eol();
768 	db_radix = old_radix;
769 
770 	/* If no argument is provided the watchdog will just be disabled. */
771 	if (err == 0) {
772 		db_printf("No argument provided, disabling watchdog\n");
773 		tout = 0;
774 	} else if ((tout & WD_INTERVAL) == WD_TO_NEVER) {
775 		db_error("Out of range watchdog interval\n");
776 		return;
777 	}
778 	EVENTHANDLER_INVOKE(watchdog_list, tout, &i);
779 }
780 
781 static void
782 db_gdb(db_expr_t dummy1, bool dummy2, db_expr_t dummy3, char *dummy4)
783 {
784 
785 	if (kdb_dbbe_select("gdb") != 0) {
786 		db_printf("The remote GDB backend could not be selected.\n");
787 		return;
788 	}
789 	/*
790 	 * Mark that we are done in the debugger.  kdb_trap()
791 	 * should re-enter with the new backend.
792 	 */
793 	db_cmd_loop_done = 1;
794 	db_printf("(ctrl-c will return control to ddb)\n");
795 }
796 
797 static void
798 db_stack_trace(db_expr_t tid, bool hastid, db_expr_t count, char *modif)
799 {
800 	struct thread *td;
801 	db_expr_t radix;
802 	pid_t pid;
803 	int t;
804 
805 	/*
806 	 * We parse our own arguments. We don't like the default radix.
807 	 */
808 	radix = db_radix;
809 	db_radix = 10;
810 	hastid = db_expression(&tid);
811 	t = db_read_token();
812 	if (t == tCOMMA) {
813 		if (!db_expression(&count)) {
814 			db_printf("Count missing\n");
815 			db_flush_lex();
816 			db_radix = radix;
817 			return;
818 		}
819 	} else {
820 		db_unread_token(t);
821 		count = -1;
822 	}
823 	db_skip_to_eol();
824 	db_radix = radix;
825 
826 	if (hastid) {
827 		td = kdb_thr_lookup((lwpid_t)tid);
828 		if (td == NULL)
829 			td = kdb_thr_from_pid((pid_t)tid);
830 		if (td == NULL) {
831 			db_printf("Thread %d not found\n", (int)tid);
832 			return;
833 		}
834 	} else
835 		td = kdb_thread;
836 	if (td->td_proc != NULL)
837 		pid = td->td_proc->p_pid;
838 	else
839 		pid = -1;
840 	db_printf("Tracing pid %d tid %ld td %p\n", pid, (long)td->td_tid, td);
841 	if (td->td_proc != NULL && (td->td_proc->p_flag & P_INMEM) == 0)
842 		db_printf("--- swapped out\n");
843 	else
844 		db_trace_thread(td, count);
845 }
846 
847 static void
848 _db_stack_trace_all(bool active_only)
849 {
850 	struct thread *td;
851 	jmp_buf jb;
852 	void *prev_jb;
853 
854 	for (td = kdb_thr_first(); td != NULL; td = kdb_thr_next(td)) {
855 		prev_jb = kdb_jmpbuf(jb);
856 		if (setjmp(jb) == 0) {
857 			if (td->td_state == TDS_RUNNING)
858 				db_printf("\nTracing command %s pid %d"
859 				    " tid %ld td %p (CPU %d)\n",
860 				    td->td_proc->p_comm, td->td_proc->p_pid,
861 				    (long)td->td_tid, td, td->td_oncpu);
862 			else if (active_only)
863 				continue;
864 			else
865 				db_printf("\nTracing command %s pid %d"
866 				    " tid %ld td %p\n", td->td_proc->p_comm,
867 				    td->td_proc->p_pid, (long)td->td_tid, td);
868 			if (td->td_proc->p_flag & P_INMEM)
869 				db_trace_thread(td, -1);
870 			else
871 				db_printf("--- swapped out\n");
872 			if (db_pager_quit) {
873 				kdb_jmpbuf(prev_jb);
874 				return;
875 			}
876 		}
877 		kdb_jmpbuf(prev_jb);
878 	}
879 }
880 
881 static void
882 db_stack_trace_active(db_expr_t dummy, bool dummy2, db_expr_t dummy3,
883     char *dummy4)
884 {
885 
886 	_db_stack_trace_all(true);
887 }
888 
889 static void
890 db_stack_trace_all(db_expr_t dummy, bool dummy2, db_expr_t dummy3,
891     char *dummy4)
892 {
893 
894 	_db_stack_trace_all(false);
895 }
896 
897 /*
898  * Take the parsed expression value from the command line that was parsed
899  * as a hexadecimal value and convert it as if the expression was parsed
900  * as a decimal value.  Returns -1 if the expression was not a valid
901  * decimal value.
902  */
903 db_expr_t
904 db_hex2dec(db_expr_t expr)
905 {
906 	uintptr_t x, y;
907 	db_expr_t val;
908 
909 	y = 1;
910 	val = 0;
911 	x = expr;
912 	while (x != 0) {
913 		if (x % 16 > 9)
914 			return (-1);
915 		val += (x % 16) * (y);
916 		x >>= 4;
917 		y *= 10;
918 	}
919 	return (val);
920 }
921