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 */
64int		db_cmd_loop_done;
65db_addr_t	db_dot;
66db_addr_t	db_last_addr;
67db_addr_t	db_prev;
68db_addr_t	db_next;
69
70static db_cmdfcn_t	db_dump;
71static db_cmdfcn_t	db_fncall;
72static db_cmdfcn_t	db_gdb;
73static db_cmdfcn_t	db_halt;
74static db_cmdfcn_t	db_kill;
75static db_cmdfcn_t	db_reset;
76static db_cmdfcn_t	db_stack_trace;
77static db_cmdfcn_t	db_stack_trace_active;
78static db_cmdfcn_t	db_stack_trace_all;
79static db_cmdfcn_t	db_watchdog;
80
81/*
82 * 'show' commands
83 */
84
85static struct command db_show_active_cmds[] = {
86	{ "trace",	db_stack_trace_active,	0,	NULL },
87};
88struct command_table db_show_active_table =
89    LIST_HEAD_INITIALIZER(db_show_active_table);
90
91static struct command db_show_all_cmds[] = {
92	{ "trace",	db_stack_trace_all,	0,	NULL },
93};
94struct command_table db_show_all_table =
95    LIST_HEAD_INITIALIZER(db_show_all_table);
96
97static 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};
104struct command_table db_show_table = LIST_HEAD_INITIALIZER(db_show_table);
105
106static 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,		CS_OWN,	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};
157struct command_table db_cmd_table = LIST_HEAD_INITIALIZER(db_cmd_table);
158
159static 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 */
166static bool	db_ed_style = true;
167
168/*
169 * Utility routine - discard tokens through end-of-line.
170 */
171void
172db_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
189static void	db_cmd_match(char *name, struct command *cmd,
190		    struct command **cmdp, int *resultp);
191static void	db_cmd_list(struct command_table *table);
192static int	db_cmd_search(char *name, struct command_table *table,
193		    struct command **cmdp);
194static 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 */
200void
201db_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 */
221void
222db_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 */
252void
253db_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 */
269static void
270db_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 */
305static int
306db_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
326static void
327db_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
352static void
353db_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 */
511DB_COMMAND(panic, db_panic)
512{
513	db_disable_pager();
514	panic("from debugger");
515}
516
517void
518db_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 */
547void
548db_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
555void
556db_error(const char *s)
557{
558	if (s)
559	    db_printf("%s", s);
560	db_flush_lex();
561	kdb_reenter_silent();
562}
563
564static void
565db_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. */
597typedef 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
600static __inline int
601db_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
614static void
615db_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
661static void
662db_halt(db_expr_t dummy, bool dummy2, db_expr_t dummy3, char *dummy4)
663{
664
665	cpu_halt();
666}
667
668static void
669db_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
712out:
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
727static void
728db_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
757static void
758db_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
780static void
781db_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
796static void
797db_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
843static 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
878static void
879db_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
886static void
887db_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 */
900db_expr_t
901db_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