xref: /freebsd/sys/ddb/db_command.c (revision bb15ca603fa442c72dde3f3cb8b46db6970e3950)
1 /*-
2  * Mach Operating System
3  * Copyright (c) 1991,1990 Carnegie Mellon University
4  * All Rights Reserved.
5  *
6  * Permission to use, copy, modify and distribute this software and its
7  * documentation is hereby granted, provided that both the copyright
8  * notice and this permission notice appear in all copies of the
9  * software, derivative works or modified versions, and any portions
10  * thereof, and that both notices appear in supporting documentation.
11  *
12  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS
13  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
14  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
15  *
16  * Carnegie Mellon requests users of this software to return to
17  *
18  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
19  *  School of Computer Science
20  *  Carnegie Mellon University
21  *  Pittsburgh PA 15213-3890
22  *
23  * any improvements or extensions that they make and grant Carnegie the
24  * rights to redistribute these changes.
25  */
26 /*
27  *	Author: David B. Golub, Carnegie Mellon University
28  *	Date:	7/90
29  */
30 /*
31  * Command dispatcher.
32  */
33 
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
36 
37 #include <sys/param.h>
38 #include <sys/linker_set.h>
39 #include <sys/lock.h>
40 #include <sys/kdb.h>
41 #include <sys/mutex.h>
42 #include <sys/proc.h>
43 #include <sys/reboot.h>
44 #include <sys/signalvar.h>
45 #include <sys/systm.h>
46 #include <sys/cons.h>
47 #include <sys/conf.h>
48 #include <sys/watchdog.h>
49 #include <sys/kernel.h>
50 
51 #include <ddb/ddb.h>
52 #include <ddb/db_command.h>
53 #include <ddb/db_lex.h>
54 #include <ddb/db_output.h>
55 
56 #include <machine/cpu.h>
57 #include <machine/setjmp.h>
58 
59 /*
60  * Exported global variables
61  */
62 boolean_t	db_cmd_loop_done;
63 db_addr_t	db_dot;
64 db_addr_t	db_last_addr;
65 db_addr_t	db_prev;
66 db_addr_t	db_next;
67 
68 static db_cmdfcn_t	db_dump;
69 static db_cmdfcn_t	db_fncall;
70 static db_cmdfcn_t	db_gdb;
71 static db_cmdfcn_t	db_halt;
72 static db_cmdfcn_t	db_kill;
73 static db_cmdfcn_t	db_reset;
74 static db_cmdfcn_t	db_stack_trace;
75 static db_cmdfcn_t	db_stack_trace_all;
76 static db_cmdfcn_t	db_watchdog;
77 
78 /*
79  * 'show' commands
80  */
81 
82 static struct command db_show_all_cmds[] = {
83 	{ "trace",	db_stack_trace_all,	0,	0 },
84 };
85 struct command_table db_show_all_table =
86     LIST_HEAD_INITIALIZER(db_show_all_table);
87 
88 static struct command db_show_cmds[] = {
89 	{ "all",	0,			0,	&db_show_all_table },
90 	{ "registers",	db_show_regs,		0,	0 },
91 	{ "breaks",	db_listbreak_cmd, 	0,	0 },
92 	{ "threads",	db_show_threads,	0,	0 },
93 };
94 struct command_table db_show_table = LIST_HEAD_INITIALIZER(db_show_table);
95 
96 static struct command db_cmds[] = {
97 	{ "print",	db_print_cmd,		0,	0 },
98 	{ "p",		db_print_cmd,		0,	0 },
99 	{ "examine",	db_examine_cmd,		CS_SET_DOT, 0 },
100 	{ "x",		db_examine_cmd,		CS_SET_DOT, 0 },
101 	{ "search",	db_search_cmd,		CS_OWN|CS_SET_DOT, 0 },
102 	{ "set",	db_set_cmd,		CS_OWN,	0 },
103 	{ "write",	db_write_cmd,		CS_MORE|CS_SET_DOT, 0 },
104 	{ "w",		db_write_cmd,		CS_MORE|CS_SET_DOT, 0 },
105 	{ "delete",	db_delete_cmd,		0,	0 },
106 	{ "d",		db_delete_cmd,		0,	0 },
107 	{ "dump",	db_dump,		0,	0 },
108 	{ "break",	db_breakpoint_cmd,	0,	0 },
109 	{ "b",		db_breakpoint_cmd,	0,	0 },
110 	{ "dwatch",	db_deletewatch_cmd,	0,	0 },
111 	{ "watch",	db_watchpoint_cmd,	CS_MORE,0 },
112 	{ "dhwatch",	db_deletehwatch_cmd,	0,      0 },
113 	{ "hwatch",	db_hwatchpoint_cmd,	0,      0 },
114 	{ "step",	db_single_step_cmd,	0,	0 },
115 	{ "s",		db_single_step_cmd,	0,	0 },
116 	{ "continue",	db_continue_cmd,	0,	0 },
117 	{ "c",		db_continue_cmd,	0,	0 },
118 	{ "until",	db_trace_until_call_cmd,0,	0 },
119 	{ "next",	db_trace_until_matching_cmd,0,	0 },
120 	{ "match",	db_trace_until_matching_cmd,0,	0 },
121 	{ "trace",	db_stack_trace,		CS_OWN,	0 },
122 	{ "t",		db_stack_trace,		CS_OWN,	0 },
123 	/* XXX alias for all trace */
124 	{ "alltrace",	db_stack_trace_all,	0,	0 },
125 	{ "where",	db_stack_trace,		CS_OWN,	0 },
126 	{ "bt",		db_stack_trace,		CS_OWN,	0 },
127 	{ "call",	db_fncall,		CS_OWN,	0 },
128 	{ "show",	0,			0,	&db_show_table },
129 	{ "ps",		db_ps,			0,	0 },
130 	{ "gdb",	db_gdb,			0,	0 },
131 	{ "halt",	db_halt,		0,	0 },
132 	{ "reboot",	db_reset,		0,	0 },
133 	{ "reset",	db_reset,		0,	0 },
134 	{ "kill",	db_kill,		CS_OWN,	0 },
135 	{ "watchdog",	db_watchdog,		CS_OWN,	0 },
136 	{ "thread",	db_set_thread,		CS_OWN,	0 },
137 	{ "run",	db_run_cmd,		CS_OWN,	0 },
138 	{ "script",	db_script_cmd,		CS_OWN,	0 },
139 	{ "scripts",	db_scripts_cmd,		0,	0 },
140 	{ "unscript",	db_unscript_cmd,	CS_OWN,	0 },
141 	{ "capture",	db_capture_cmd,		CS_OWN,	0 },
142 	{ "textdump",	db_textdump_cmd,	CS_OWN, 0 },
143 };
144 struct command_table db_cmd_table = LIST_HEAD_INITIALIZER(db_cmd_table);
145 
146 static struct command	*db_last_command = 0;
147 
148 /*
149  * if 'ed' style: 'dot' is set at start of last item printed,
150  * and '+' points to next line.
151  * Otherwise: 'dot' points to next item, '..' points to last.
152  */
153 static boolean_t	db_ed_style = TRUE;
154 
155 /*
156  * Utility routine - discard tokens through end-of-line.
157  */
158 void
159 db_skip_to_eol()
160 {
161 	int	t;
162 	do {
163 	    t = db_read_token();
164 	} while (t != tEOL);
165 }
166 
167 /*
168  * Results of command search.
169  */
170 #define	CMD_UNIQUE	0
171 #define	CMD_FOUND	1
172 #define	CMD_NONE	2
173 #define	CMD_AMBIGUOUS	3
174 #define	CMD_HELP	4
175 
176 static void	db_cmd_match(char *name, struct command *cmd,
177 		    struct command **cmdp, int *resultp);
178 static void	db_cmd_list(struct command_table *table);
179 static int	db_cmd_search(char *name, struct command_table *table,
180 		    struct command **cmdp);
181 static void	db_command(struct command **last_cmdp,
182 		    struct command_table *cmd_table, int dopager);
183 
184 /*
185  * Initialize the command lists from the static tables.
186  */
187 void
188 db_command_init(void)
189 {
190 #define	N(a)	(sizeof(a) / sizeof(a[0]))
191 	int i;
192 
193 	for (i = 0; i < N(db_cmds); i++)
194 		db_command_register(&db_cmd_table, &db_cmds[i]);
195 	for (i = 0; i < N(db_show_cmds); i++)
196 		db_command_register(&db_show_table, &db_show_cmds[i]);
197 	for (i = 0; i < N(db_show_all_cmds); i++)
198 		db_command_register(&db_show_all_table, &db_show_all_cmds[i]);
199 #undef N
200 }
201 
202 /*
203  * Register a command.
204  */
205 void
206 db_command_register(struct command_table *list, struct command *cmd)
207 {
208 	struct command *c, *last;
209 
210 	last = NULL;
211 	LIST_FOREACH(c, list, next) {
212 		int n = strcmp(cmd->name, c->name);
213 
214 		/* Check that the command is not already present. */
215 		if (n == 0) {
216 			printf("%s: Warning, the command \"%s\" already exists;"
217 			     " ignoring request\n", __func__, cmd->name);
218 			return;
219 		}
220 		if (n < 0) {
221 			/* NB: keep list sorted lexicographically */
222 			LIST_INSERT_BEFORE(c, cmd, next);
223 			return;
224 		}
225 		last = c;
226 	}
227 	if (last == NULL)
228 		LIST_INSERT_HEAD(list, cmd, next);
229 	else
230 		LIST_INSERT_AFTER(last, cmd, next);
231 }
232 
233 /*
234  * Remove a command previously registered with db_command_register.
235  */
236 void
237 db_command_unregister(struct command_table *list, struct command *cmd)
238 {
239 	struct command *c;
240 
241 	LIST_FOREACH(c, list, next) {
242 		if (cmd == c) {
243 			LIST_REMOVE(cmd, next);
244 			return;
245 		}
246 	}
247 	/* NB: intentionally quiet */
248 }
249 
250 /*
251  * Helper function to match a single command.
252  */
253 static void
254 db_cmd_match(name, cmd, cmdp, resultp)
255 	char *		name;
256 	struct command	*cmd;
257 	struct command	**cmdp;	/* out */
258 	int *		resultp;
259 {
260 	char *lp, *rp;
261 	int c;
262 
263 	lp = name;
264 	rp = cmd->name;
265 	while ((c = *lp) == *rp) {
266 		if (c == 0) {
267 			/* complete match */
268 			*cmdp = cmd;
269 			*resultp = CMD_UNIQUE;
270 			return;
271 		}
272 		lp++;
273 		rp++;
274 	}
275 	if (c == 0) {
276 		/* end of name, not end of command -
277 		   partial match */
278 		if (*resultp == CMD_FOUND) {
279 			*resultp = CMD_AMBIGUOUS;
280 			/* but keep looking for a full match -
281 			   this lets us match single letters */
282 		} else {
283 			*cmdp = cmd;
284 			*resultp = CMD_FOUND;
285 		}
286 	}
287 }
288 
289 /*
290  * Search for command prefix.
291  */
292 static int
293 db_cmd_search(name, table, cmdp)
294 	char *		name;
295 	struct command_table *table;
296 	struct command	**cmdp;	/* out */
297 {
298 	struct command	*cmd;
299 	int		result = CMD_NONE;
300 
301 	LIST_FOREACH(cmd, table, next) {
302 		db_cmd_match(name,cmd,cmdp,&result);
303 		if (result == CMD_UNIQUE)
304 			break;
305 	}
306 
307 	if (result == CMD_NONE) {
308 		/* check for 'help' */
309 		if (name[0] == 'h' && name[1] == 'e'
310 		    && name[2] == 'l' && name[3] == 'p')
311 			result = CMD_HELP;
312 	}
313 	return (result);
314 }
315 
316 static void
317 db_cmd_list(table)
318 	struct command_table *table;
319 {
320 	register struct command	*cmd;
321 
322 	LIST_FOREACH(cmd, table, next) {
323 		db_printf("%-12s", cmd->name);
324 		db_end_line(12);
325 	}
326 }
327 
328 static void
329 db_command(last_cmdp, cmd_table, dopager)
330 	struct command	**last_cmdp;	/* IN_OUT */
331 	struct command_table *cmd_table;
332 	int dopager;
333 {
334 	struct command	*cmd = NULL;
335 	int		t;
336 	char		modif[TOK_STRING_SIZE];
337 	db_expr_t	addr, count;
338 	boolean_t	have_addr = FALSE;
339 	int		result;
340 
341 	t = db_read_token();
342 	if (t == tEOL) {
343 	    /* empty line repeats last command, at 'next' */
344 	    cmd = *last_cmdp;
345 	    addr = (db_expr_t)db_next;
346 	    have_addr = FALSE;
347 	    count = 1;
348 	    modif[0] = '\0';
349 	}
350 	else if (t == tEXCL) {
351 	    db_fncall((db_expr_t)0, (boolean_t)0, (db_expr_t)0, (char *)0);
352 	    return;
353 	}
354 	else if (t != tIDENT) {
355 	    db_printf("?\n");
356 	    db_flush_lex();
357 	    return;
358 	}
359 	else {
360 	    /*
361 	     * Search for command
362 	     */
363 	    while (cmd_table) {
364 		result = db_cmd_search(db_tok_string,
365 				       cmd_table,
366 				       &cmd);
367 		switch (result) {
368 		    case CMD_NONE:
369 			db_printf("No such command\n");
370 			db_flush_lex();
371 			return;
372 		    case CMD_AMBIGUOUS:
373 			db_printf("Ambiguous\n");
374 			db_flush_lex();
375 			return;
376 		    case CMD_HELP:
377 			db_cmd_list(cmd_table);
378 			db_flush_lex();
379 			return;
380 		    default:
381 			break;
382 		}
383 		if ((cmd_table = cmd->more) != NULL) {
384 		    t = db_read_token();
385 		    if (t != tIDENT) {
386 			db_cmd_list(cmd_table);
387 			db_flush_lex();
388 			return;
389 		    }
390 		}
391 	    }
392 
393 	    if ((cmd->flag & CS_OWN) == 0) {
394 		/*
395 		 * Standard syntax:
396 		 * command [/modifier] [addr] [,count]
397 		 */
398 		t = db_read_token();
399 		if (t == tSLASH) {
400 		    t = db_read_token();
401 		    if (t != tIDENT) {
402 			db_printf("Bad modifier\n");
403 			db_flush_lex();
404 			return;
405 		    }
406 		    db_strcpy(modif, db_tok_string);
407 		}
408 		else {
409 		    db_unread_token(t);
410 		    modif[0] = '\0';
411 		}
412 
413 		if (db_expression(&addr)) {
414 		    db_dot = (db_addr_t) addr;
415 		    db_last_addr = db_dot;
416 		    have_addr = TRUE;
417 		}
418 		else {
419 		    addr = (db_expr_t) db_dot;
420 		    have_addr = FALSE;
421 		}
422 		t = db_read_token();
423 		if (t == tCOMMA) {
424 		    if (!db_expression(&count)) {
425 			db_printf("Count missing\n");
426 			db_flush_lex();
427 			return;
428 		    }
429 		}
430 		else {
431 		    db_unread_token(t);
432 		    count = -1;
433 		}
434 		if ((cmd->flag & CS_MORE) == 0) {
435 		    db_skip_to_eol();
436 		}
437 	    }
438 	}
439 	*last_cmdp = cmd;
440 	if (cmd != 0) {
441 	    /*
442 	     * Execute the command.
443 	     */
444 	    if (dopager)
445 		db_enable_pager();
446 	    else
447 		db_disable_pager();
448 	    (*cmd->fcn)(addr, have_addr, count, modif);
449 	    if (dopager)
450 		db_disable_pager();
451 
452 	    if (cmd->flag & CS_SET_DOT) {
453 		/*
454 		 * If command changes dot, set dot to
455 		 * previous address displayed (if 'ed' style).
456 		 */
457 		if (db_ed_style) {
458 		    db_dot = db_prev;
459 		}
460 		else {
461 		    db_dot = db_next;
462 		}
463 	    }
464 	    else {
465 		/*
466 		 * If command does not change dot,
467 		 * set 'next' location to be the same.
468 		 */
469 		db_next = db_dot;
470 	    }
471 	}
472 }
473 
474 /*
475  * At least one non-optional command must be implemented using
476  * DB_COMMAND() so that db_cmd_set gets created.  Here is one.
477  */
478 DB_COMMAND(panic, db_panic)
479 {
480 	db_disable_pager();
481 	panic("from debugger");
482 }
483 
484 void
485 db_command_loop()
486 {
487 	/*
488 	 * Initialize 'prev' and 'next' to dot.
489 	 */
490 	db_prev = db_dot;
491 	db_next = db_dot;
492 
493 	db_cmd_loop_done = 0;
494 	while (!db_cmd_loop_done) {
495 	    if (db_print_position() != 0)
496 		db_printf("\n");
497 
498 	    db_printf("db> ");
499 	    (void) db_read_line();
500 
501 	    db_command(&db_last_command, &db_cmd_table, /* dopager */ 1);
502 	}
503 }
504 
505 /*
506  * Execute a command on behalf of a script.  The caller is responsible for
507  * making sure that the command string is < DB_MAXLINE or it will be
508  * truncated.
509  *
510  * XXXRW: Runs by injecting faked input into DDB input stream; it would be
511  * nicer to use an alternative approach that didn't mess with the previous
512  * command buffer.
513  */
514 void
515 db_command_script(const char *command)
516 {
517 	db_prev = db_next = db_dot;
518 	db_inject_line(command);
519 	db_command(&db_last_command, &db_cmd_table, /* dopager */ 0);
520 }
521 
522 void
523 db_error(s)
524 	const char *s;
525 {
526 	if (s)
527 	    db_printf("%s", s);
528 	db_flush_lex();
529 	kdb_reenter();
530 }
531 
532 static void
533 db_dump(db_expr_t dummy, boolean_t dummy2, db_expr_t dummy3, char *dummy4)
534 {
535 	int error;
536 
537 	error = doadump(FALSE);
538 	if (error) {
539 		db_printf("Cannot dump: ");
540 		switch (error) {
541 		case EBUSY:
542 			db_printf("debugger got invoked while dumping.\n");
543 			break;
544 		case ENXIO:
545 			db_printf("no dump device specified.\n");
546 			break;
547 		default:
548 			db_printf("unknown error (error=%d).\n", error);
549 			break;
550 		}
551 	}
552 }
553 
554 /*
555  * Call random function:
556  * !expr(arg,arg,arg)
557  */
558 
559 /* The generic implementation supports a maximum of 10 arguments. */
560 typedef db_expr_t __db_f(db_expr_t, db_expr_t, db_expr_t, db_expr_t,
561     db_expr_t, db_expr_t, db_expr_t, db_expr_t, db_expr_t, db_expr_t);
562 
563 static __inline int
564 db_fncall_generic(db_expr_t addr, db_expr_t *rv, int nargs, db_expr_t args[])
565 {
566 	__db_f *f = (__db_f *)addr;
567 
568 	if (nargs > 10) {
569 		db_printf("Too many arguments (max 10)\n");
570 		return (0);
571 	}
572 	*rv = (*f)(args[0], args[1], args[2], args[3], args[4], args[5],
573 	    args[6], args[7], args[8], args[9]);
574 	return (1);
575 }
576 
577 static void
578 db_fncall(dummy1, dummy2, dummy3, dummy4)
579 	db_expr_t	dummy1;
580 	boolean_t	dummy2;
581 	db_expr_t	dummy3;
582 	char *		dummy4;
583 {
584 	db_expr_t	fn_addr;
585 	db_expr_t	args[DB_MAXARGS];
586 	int		nargs = 0;
587 	db_expr_t	retval;
588 	int		t;
589 
590 	if (!db_expression(&fn_addr)) {
591 	    db_printf("Bad function\n");
592 	    db_flush_lex();
593 	    return;
594 	}
595 
596 	t = db_read_token();
597 	if (t == tLPAREN) {
598 	    if (db_expression(&args[0])) {
599 		nargs++;
600 		while ((t = db_read_token()) == tCOMMA) {
601 		    if (nargs == DB_MAXARGS) {
602 			db_printf("Too many arguments (max %d)\n", DB_MAXARGS);
603 			db_flush_lex();
604 			return;
605 		    }
606 		    if (!db_expression(&args[nargs])) {
607 			db_printf("Argument missing\n");
608 			db_flush_lex();
609 			return;
610 		    }
611 		    nargs++;
612 		}
613 		db_unread_token(t);
614 	    }
615 	    if (db_read_token() != tRPAREN) {
616 		db_printf("?\n");
617 		db_flush_lex();
618 		return;
619 	    }
620 	}
621 	db_skip_to_eol();
622 	db_disable_pager();
623 
624 	if (DB_CALL(fn_addr, &retval, nargs, args))
625 		db_printf("= %#lr\n", (long)retval);
626 }
627 
628 static void
629 db_halt(db_expr_t dummy, boolean_t dummy2, db_expr_t dummy3, char *dummy4)
630 {
631 
632 	cpu_halt();
633 }
634 
635 static void
636 db_kill(dummy1, dummy2, dummy3, dummy4)
637 	db_expr_t	dummy1;
638 	boolean_t	dummy2;
639 	db_expr_t	dummy3;
640 	char *		dummy4;
641 {
642 	db_expr_t old_radix, pid, sig;
643 	struct proc *p;
644 
645 #define DB_ERROR(f)	do { db_printf f; db_flush_lex(); goto out; } while (0)
646 
647 	/*
648 	 * PIDs and signal numbers are typically represented in base
649 	 * 10, so make that the default here.  It can, of course, be
650 	 * overridden by specifying a prefix.
651 	 */
652 	old_radix = db_radix;
653 	db_radix = 10;
654 	/* Retrieve arguments. */
655 	if (!db_expression(&sig))
656 		DB_ERROR(("Missing signal number\n"));
657 	if (!db_expression(&pid))
658 		DB_ERROR(("Missing process ID\n"));
659 	db_skip_to_eol();
660 	if (!_SIG_VALID(sig))
661 		DB_ERROR(("Signal number out of range\n"));
662 
663 	/*
664 	 * Find the process in question.  allproc_lock is not needed
665 	 * since we're in DDB.
666 	 */
667 	/* sx_slock(&allproc_lock); */
668 	FOREACH_PROC_IN_SYSTEM(p)
669 	    if (p->p_pid == pid)
670 		    break;
671 	/* sx_sunlock(&allproc_lock); */
672 	if (p == NULL)
673 		DB_ERROR(("Can't find process with pid %ld\n", (long) pid));
674 
675 	/* If it's already locked, bail; otherwise, do the deed. */
676 	if (PROC_TRYLOCK(p) == 0)
677 		DB_ERROR(("Can't lock process with pid %ld\n", (long) pid));
678 	else {
679 		pksignal(p, sig, NULL);
680 		PROC_UNLOCK(p);
681 	}
682 
683 out:
684 	db_radix = old_radix;
685 #undef DB_ERROR
686 }
687 
688 /*
689  * Reboot.  In case there is an additional argument, take it as delay in
690  * seconds.  Default to 15s if we cannot parse it and make sure we will
691  * never wait longer than 1 week.  Some code is similar to
692  * kern_shutdown.c:shutdown_panic().
693  */
694 #ifndef	DB_RESET_MAXDELAY
695 #define	DB_RESET_MAXDELAY	(3600 * 24 * 7)
696 #endif
697 
698 static void
699 db_reset(db_expr_t addr, boolean_t have_addr, db_expr_t count __unused,
700     char *modif __unused)
701 {
702 	int delay, loop;
703 
704 	if (have_addr) {
705 		delay = (int)db_hex2dec(addr);
706 
707 		/* If we parse to fail, use 15s. */
708 		if (delay == -1)
709 			delay = 15;
710 
711 		/* Cap at one week. */
712 		if ((uintmax_t)delay > (uintmax_t)DB_RESET_MAXDELAY)
713 			delay = DB_RESET_MAXDELAY;
714 
715 		db_printf("Automatic reboot in %d seconds - "
716 		    "press a key on the console to abort\n", delay);
717 		for (loop = delay * 10; loop > 0; --loop) {
718 			DELAY(1000 * 100); /* 1/10th second */
719 			/* Did user type a key? */
720 			if (cncheckc() != -1)
721 				return;
722 		}
723 	}
724 
725 	cpu_reset();
726 }
727 
728 static void
729 db_watchdog(dummy1, dummy2, dummy3, dummy4)
730 	db_expr_t	dummy1;
731 	boolean_t	dummy2;
732 	db_expr_t	dummy3;
733 	char *		dummy4;
734 {
735 	db_expr_t old_radix, tout;
736 	int err, i;
737 
738 	old_radix = db_radix;
739 	db_radix = 10;
740 	err = db_expression(&tout);
741 	db_skip_to_eol();
742 	db_radix = old_radix;
743 
744 	/* If no argument is provided the watchdog will just be disabled. */
745 	if (err == 0) {
746 		db_printf("No argument provided, disabling watchdog\n");
747 		tout = 0;
748 	} else if ((tout & WD_INTERVAL) == WD_TO_NEVER) {
749 		db_error("Out of range watchdog interval\n");
750 		return;
751 	}
752 	EVENTHANDLER_INVOKE(watchdog_list, tout, &i);
753 }
754 
755 static void
756 db_gdb(db_expr_t dummy1, boolean_t dummy2, db_expr_t dummy3, char *dummy4)
757 {
758 
759 	if (kdb_dbbe_select("gdb") != 0) {
760 		db_printf("The remote GDB backend could not be selected.\n");
761 		return;
762 	}
763 	/*
764 	 * Mark that we are done in the debugger.  kdb_trap()
765 	 * should re-enter with the new backend.
766 	 */
767 	db_cmd_loop_done = 1;
768 	db_printf("(ctrl-c will return control to ddb)\n");
769 }
770 
771 static void
772 db_stack_trace(db_expr_t tid, boolean_t hastid, db_expr_t count, char *modif)
773 {
774 	struct thread *td;
775 	db_expr_t radix;
776 	pid_t pid;
777 	int t;
778 
779 	/*
780 	 * We parse our own arguments. We don't like the default radix.
781 	 */
782 	radix = db_radix;
783 	db_radix = 10;
784 	hastid = db_expression(&tid);
785 	t = db_read_token();
786 	if (t == tCOMMA) {
787 		if (!db_expression(&count)) {
788 			db_printf("Count missing\n");
789 			db_flush_lex();
790 			return;
791 		}
792 	} else {
793 		db_unread_token(t);
794 		count = -1;
795 	}
796 	db_skip_to_eol();
797 	db_radix = radix;
798 
799 	if (hastid) {
800 		td = kdb_thr_lookup((lwpid_t)tid);
801 		if (td == NULL)
802 			td = kdb_thr_from_pid((pid_t)tid);
803 		if (td == NULL) {
804 			db_printf("Thread %d not found\n", (int)tid);
805 			return;
806 		}
807 	} else
808 		td = kdb_thread;
809 	if (td->td_proc != NULL)
810 		pid = td->td_proc->p_pid;
811 	else
812 		pid = -1;
813 	db_printf("Tracing pid %d tid %ld td %p\n", pid, (long)td->td_tid, td);
814 	db_trace_thread(td, count);
815 }
816 
817 static void
818 db_stack_trace_all(db_expr_t dummy, boolean_t dummy2, db_expr_t dummy3,
819     char *dummy4)
820 {
821 	struct proc *p;
822 	struct thread *td;
823 	jmp_buf jb;
824 	void *prev_jb;
825 
826 	FOREACH_PROC_IN_SYSTEM(p) {
827 		prev_jb = kdb_jmpbuf(jb);
828 		if (setjmp(jb) == 0) {
829 			FOREACH_THREAD_IN_PROC(p, td) {
830 				db_printf("\nTracing command %s pid %d tid %ld td %p\n",
831 					  p->p_comm, p->p_pid, (long)td->td_tid, td);
832 				db_trace_thread(td, -1);
833 				if (db_pager_quit) {
834 					kdb_jmpbuf(prev_jb);
835 					return;
836 				}
837 			}
838 		}
839 		kdb_jmpbuf(prev_jb);
840 	}
841 }
842 
843 /*
844  * Take the parsed expression value from the command line that was parsed
845  * as a hexadecimal value and convert it as if the expression was parsed
846  * as a decimal value.  Returns -1 if the expression was not a valid
847  * decimal value.
848  */
849 db_expr_t
850 db_hex2dec(db_expr_t expr)
851 {
852 	uintptr_t x, y;
853 	db_expr_t val;
854 
855 	y = 1;
856 	val = 0;
857 	x = expr;
858 	while (x != 0) {
859 		if (x % 16 > 9)
860 			return (-1);
861 		val += (x % 16) * (y);
862 		x >>= 4;
863 		y *= 10;
864 	}
865 	return (val);
866 }
867