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/param.h>
37#include <sys/conf.h>
38#include <sys/cons.h>
39#include <sys/eventhandler.h>
40#include <sys/kdb.h>
41#include <sys/kernel.h>
42#include <sys/linker_set.h>
43#include <sys/lock.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/watchdog.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#include <security/mac/mac_framework.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#define	DB_CMD(_name, _func, _flags)	\
82{					\
83	.name =	(_name),		\
84	.fcn =	(_func),		\
85	.flag =	(_flags),		\
86	.more = NULL,			\
87}
88#define	DB_TABLE(_name, _more)		\
89{					\
90	.name =	(_name),		\
91	.fcn =	NULL,			\
92	.more =	(_more),		\
93}
94
95static struct db_command db_show_active_cmds[] = {
96	DB_CMD("trace",		db_stack_trace_active,	DB_CMD_MEMSAFE),
97};
98struct db_command_table db_show_active_table =
99    LIST_HEAD_INITIALIZER(db_show_active_table);
100
101static struct db_command db_show_all_cmds[] = {
102	DB_CMD("trace",		db_stack_trace_all,	DB_CMD_MEMSAFE),
103};
104struct db_command_table db_show_all_table =
105    LIST_HEAD_INITIALIZER(db_show_all_table);
106
107static struct db_command db_show_cmds[] = {
108	DB_TABLE("active",	&db_show_active_table),
109	DB_TABLE("all",		&db_show_all_table),
110	DB_CMD("registers",	db_show_regs,		DB_CMD_MEMSAFE),
111	DB_CMD("breaks",	db_listbreak_cmd,	DB_CMD_MEMSAFE),
112	DB_CMD("threads",	db_show_threads,	DB_CMD_MEMSAFE),
113};
114struct db_command_table db_show_table = LIST_HEAD_INITIALIZER(db_show_table);
115
116static struct db_command db_cmds[] = {
117	DB_TABLE("show",	&db_show_table),
118	DB_CMD("print",		db_print_cmd,		0),
119	DB_CMD("p",		db_print_cmd,		0),
120	DB_CMD("examine",	db_examine_cmd,		CS_SET_DOT),
121	DB_CMD("x",		db_examine_cmd,		CS_SET_DOT),
122	DB_CMD("search",	db_search_cmd,		CS_OWN|CS_SET_DOT),
123	DB_CMD("set",		db_set_cmd,		CS_OWN|DB_CMD_MEMSAFE),
124	DB_CMD("write",		db_write_cmd,		CS_MORE|CS_SET_DOT),
125	DB_CMD("w",		db_write_cmd,		CS_MORE|CS_SET_DOT),
126	DB_CMD("delete",	db_delete_cmd,		0),
127	DB_CMD("d",		db_delete_cmd,		0),
128	DB_CMD("dump",		db_dump,		DB_CMD_MEMSAFE),
129#ifdef HAS_HW_BREAKPOINT
130	DB_CMD("dhbreak",	db_deletehbreak_cmd,	0),
131	DB_CMD("hbreak",	db_hbreakpoint_cmd,	0),
132#endif
133	DB_CMD("break",		db_breakpoint_cmd,	0),
134	DB_CMD("b",		db_breakpoint_cmd,	0),
135	DB_CMD("dwatch",	db_deletewatch_cmd,	0),
136	DB_CMD("watch",		db_watchpoint_cmd,	CS_MORE),
137	DB_CMD("dhwatch",	db_deletehwatch_cmd,	0),
138	DB_CMD("hwatch",	db_hwatchpoint_cmd,	0),
139	DB_CMD("step",		db_single_step_cmd,	DB_CMD_MEMSAFE),
140	DB_CMD("s",		db_single_step_cmd,	DB_CMD_MEMSAFE),
141	DB_CMD("continue",	db_continue_cmd,	DB_CMD_MEMSAFE),
142	DB_CMD("c",		db_continue_cmd,	DB_CMD_MEMSAFE),
143	DB_CMD("until",		db_trace_until_call_cmd, DB_CMD_MEMSAFE),
144	DB_CMD("next",		db_trace_until_matching_cmd, DB_CMD_MEMSAFE),
145	DB_CMD("match",		db_trace_until_matching_cmd, 0),
146	DB_CMD("trace",		db_stack_trace,		CS_OWN|DB_CMD_MEMSAFE),
147	DB_CMD("t",		db_stack_trace,		CS_OWN|DB_CMD_MEMSAFE),
148	/* XXX alias for active trace */
149	DB_CMD("acttrace",	db_stack_trace_active,	DB_CMD_MEMSAFE),
150	/* XXX alias for all trace */
151	DB_CMD("alltrace",	db_stack_trace_all,	DB_CMD_MEMSAFE),
152	DB_CMD("where",		db_stack_trace,		CS_OWN|DB_CMD_MEMSAFE),
153	DB_CMD("bt",		db_stack_trace,		CS_OWN|DB_CMD_MEMSAFE),
154	DB_CMD("call",		db_fncall,		CS_OWN),
155	DB_CMD("ps",		db_ps,			DB_CMD_MEMSAFE),
156	DB_CMD("gdb",		db_gdb,			0),
157	DB_CMD("halt",		db_halt,		DB_CMD_MEMSAFE),
158	DB_CMD("reboot",	db_reset,		DB_CMD_MEMSAFE),
159	DB_CMD("reset",		db_reset,		DB_CMD_MEMSAFE),
160	DB_CMD("kill",		db_kill,		CS_OWN|DB_CMD_MEMSAFE),
161	DB_CMD("watchdog",	db_watchdog,		CS_OWN|DB_CMD_MEMSAFE),
162	DB_CMD("thread",	db_set_thread,		0),
163	DB_CMD("run",		db_run_cmd,		CS_OWN|DB_CMD_MEMSAFE),
164	DB_CMD("script",	db_script_cmd,		CS_OWN|DB_CMD_MEMSAFE),
165	DB_CMD("scripts",	db_scripts_cmd,		DB_CMD_MEMSAFE),
166	DB_CMD("unscript",	db_unscript_cmd,	CS_OWN|DB_CMD_MEMSAFE),
167	DB_CMD("capture",	db_capture_cmd,		CS_OWN|DB_CMD_MEMSAFE),
168	DB_CMD("textdump",	db_textdump_cmd,	CS_OWN|DB_CMD_MEMSAFE),
169	DB_CMD("findstack",	db_findstack_cmd,	0),
170	DB_CMD("pprint",	db_pprint_cmd,		CS_OWN),
171};
172struct db_command_table db_cmd_table = LIST_HEAD_INITIALIZER(db_cmd_table);
173
174#undef DB_CMD
175#undef DB_TABLE
176
177static struct db_command *db_last_command = NULL;
178
179/*
180 * if 'ed' style: 'dot' is set at start of last item printed,
181 * and '+' points to next line.
182 * Otherwise: 'dot' points to next item, '..' points to last.
183 */
184static bool	db_ed_style = true;
185
186/*
187 * Utility routine - discard tokens through end-of-line.
188 */
189void
190db_skip_to_eol(void)
191{
192	int t;
193
194	do {
195		t = db_read_token();
196	} while (t != tEOL);
197}
198
199/*
200 * Results of command search.
201 */
202#define	CMD_UNIQUE	0
203#define	CMD_FOUND	1
204#define	CMD_NONE	2
205#define	CMD_AMBIGUOUS	3
206#define	CMD_HELP	4
207
208static void	db_cmd_match(char *name, struct db_command *cmd,
209		    struct db_command **cmdp, int *resultp);
210static void	db_cmd_list(struct db_command_table *table);
211static int	db_cmd_search(char *name, struct db_command_table *table,
212		    struct db_command **cmdp);
213static void	db_command(struct db_command **last_cmdp,
214		    struct db_command_table *cmd_table, bool dopager);
215
216/*
217 * Initialize the command lists from the static tables.
218 */
219void
220db_command_init(void)
221{
222	int i;
223
224	for (i = 0; i < nitems(db_cmds); i++)
225		db_command_register(&db_cmd_table, &db_cmds[i]);
226	for (i = 0; i < nitems(db_show_cmds); i++)
227		db_command_register(&db_show_table, &db_show_cmds[i]);
228	for (i = 0; i < nitems(db_show_active_cmds); i++)
229		db_command_register(&db_show_active_table,
230		    &db_show_active_cmds[i]);
231	for (i = 0; i < nitems(db_show_all_cmds); i++)
232		db_command_register(&db_show_all_table, &db_show_all_cmds[i]);
233}
234
235/*
236 * Register a command.
237 */
238void
239db_command_register(struct db_command_table *list, struct db_command *cmd)
240{
241	struct db_command *c, *last;
242
243#ifdef MAC
244	if (mac_ddb_command_register(list, cmd)) {
245		printf("%s: MAC policy refused registration of command %s\n",
246		    __func__, cmd->name);
247		return;
248	}
249#endif
250	last = NULL;
251	LIST_FOREACH(c, list, next) {
252		int n = strcmp(cmd->name, c->name);
253
254		/* Check that the command is not already present. */
255		if (n == 0) {
256			printf("%s: Warning, the command \"%s\" already exists;"
257			     " ignoring request\n", __func__, cmd->name);
258			return;
259		}
260		if (n < 0) {
261			/* NB: keep list sorted lexicographically */
262			LIST_INSERT_BEFORE(c, cmd, next);
263			return;
264		}
265		last = c;
266	}
267	if (last == NULL)
268		LIST_INSERT_HEAD(list, cmd, next);
269	else
270		LIST_INSERT_AFTER(last, cmd, next);
271}
272
273/*
274 * Remove a command previously registered with db_command_register.
275 */
276void
277db_command_unregister(struct db_command_table *list, struct db_command *cmd)
278{
279	struct db_command *c;
280
281	LIST_FOREACH(c, list, next) {
282		if (cmd == c) {
283			LIST_REMOVE(cmd, next);
284			return;
285		}
286	}
287	/* NB: intentionally quiet */
288}
289
290/*
291 * Helper function to match a single command.
292 */
293static void
294db_cmd_match(char *name, struct db_command *cmd, struct db_command **cmdp,
295    int *resultp)
296{
297	char *lp, *rp;
298	int c;
299
300	lp = name;
301	rp = cmd->name;
302	while ((c = *lp) == *rp) {
303		if (c == 0) {
304			/* complete match */
305			*cmdp = cmd;
306			*resultp = CMD_UNIQUE;
307			return;
308		}
309		lp++;
310		rp++;
311	}
312	if (c == 0) {
313		/* end of name, not end of command -
314		   partial match */
315		if (*resultp == CMD_FOUND) {
316			*resultp = CMD_AMBIGUOUS;
317			/* but keep looking for a full match -
318			   this lets us match single letters */
319		} else if (*resultp == CMD_NONE) {
320			*cmdp = cmd;
321			*resultp = CMD_FOUND;
322		}
323	}
324}
325
326/*
327 * Search for command prefix.
328 */
329static int
330db_cmd_search(char *name, struct db_command_table *table,
331    struct db_command **cmdp)
332{
333	struct db_command *cmd;
334	int result = CMD_NONE;
335
336	LIST_FOREACH(cmd, table, next) {
337		db_cmd_match(name,cmd,cmdp,&result);
338		if (result == CMD_UNIQUE)
339			break;
340	}
341
342	if (result == CMD_NONE) {
343		/* check for 'help' */
344		if (name[0] == 'h' && name[1] == 'e'
345		    && name[2] == 'l' && name[3] == 'p')
346			result = CMD_HELP;
347	}
348	return (result);
349}
350
351static void
352db_cmd_list(struct db_command_table *table)
353{
354	struct db_command *cmd;
355	int have_subcommands;
356
357	have_subcommands = 0;
358	LIST_FOREACH(cmd, table, next) {
359		if (cmd->more != NULL)
360			have_subcommands++;
361		db_printf("%-16s", cmd->name);
362		db_end_line(16);
363	}
364
365	if (have_subcommands > 0) {
366		db_printf("\nThe following have subcommands; append \"help\" "
367		    "to list (e.g. \"show help\"):\n");
368		LIST_FOREACH(cmd, table, next) {
369			if (cmd->more == NULL)
370				continue;
371			db_printf("%-16s", cmd->name);
372			db_end_line(16);
373		}
374	}
375}
376
377static void
378db_command(struct db_command **last_cmdp, struct db_command_table *cmd_table,
379    bool dopager)
380{
381	char modif[TOK_STRING_SIZE];
382	struct db_command *cmd = NULL;
383	db_expr_t addr, count;
384	int t, result;
385	bool have_addr = false;
386
387	t = db_read_token();
388	if (t == tEOL) {
389		/* empty line repeats last command, at 'next' */
390		cmd = *last_cmdp;
391		addr = (db_expr_t)db_next;
392		have_addr = false;
393		count = 1;
394		modif[0] = '\0';
395	} else if (t == tEXCL) {
396		db_fncall((db_expr_t)0, false, (db_expr_t)0, NULL);
397		return;
398	} else if (t != tIDENT) {
399		db_printf("Unrecognized input; use \"help\" "
400	            "to list available commands\n");
401		db_flush_lex();
402		return;
403	} else {
404		/*
405		 * Search for command
406		 */
407		while (cmd_table != NULL) {
408			result = db_cmd_search(db_tok_string, cmd_table, &cmd);
409			switch (result) {
410			case CMD_NONE:
411				db_printf("No such command; use \"help\" "
412				    "to list available commands\n");
413				db_flush_lex();
414				return;
415			case CMD_AMBIGUOUS:
416				db_printf("Ambiguous\n");
417				db_flush_lex();
418				return;
419			case CMD_HELP:
420				if (cmd_table == &db_cmd_table) {
421					db_printf("This is ddb(4), the kernel debugger; "
422					    "see https://man.FreeBSD.org/ddb/4 for help.\n");
423					db_printf("Use \"bt\" for backtrace, \"dump\" for "
424					    "kernel core dump, \"reset\" to reboot.\n");
425					db_printf("Available commands:\n");
426				}
427				db_cmd_list(cmd_table);
428				db_flush_lex();
429				return;
430			case CMD_UNIQUE:
431			case CMD_FOUND:
432				break;
433			}
434			if ((cmd_table = cmd->more) != NULL) {
435				t = db_read_token();
436				if (t != tIDENT) {
437					db_printf("Subcommand required; "
438					    "available subcommands:\n");
439					db_cmd_list(cmd_table);
440					db_flush_lex();
441					return;
442				}
443			}
444		}
445
446		if ((cmd->flag & CS_OWN) == 0) {
447			/*
448			 * Standard syntax:
449			 * command [/modifier] [addr] [,count]
450			 */
451			t = db_read_token();
452			if (t == tSLASH) {
453				t = db_read_token();
454				if (t != tIDENT) {
455					db_printf("Bad modifier\n");
456					db_flush_lex();
457					return;
458				}
459				db_strcpy(modif, db_tok_string);
460			} else {
461				db_unread_token(t);
462				modif[0] = '\0';
463			}
464
465			if (db_expression(&addr)) {
466				db_dot = (db_addr_t) addr;
467				db_last_addr = db_dot;
468				have_addr = true;
469			} else {
470				addr = (db_expr_t) db_dot;
471				have_addr = false;
472			}
473
474			t = db_read_token();
475			if (t == tCOMMA) {
476				if (!db_expression(&count)) {
477					db_printf("Count missing\n");
478					db_flush_lex();
479					return;
480				}
481			} else {
482				db_unread_token(t);
483				count = -1;
484			}
485
486			if ((cmd->flag & CS_MORE) == 0) {
487				db_skip_to_eol();
488			}
489		}
490	}
491
492	*last_cmdp = cmd;
493	if (cmd != NULL) {
494#ifdef MAC
495		if (mac_ddb_command_exec(cmd, addr, have_addr, count, modif)) {
496			db_printf("MAC prevented execution of command %s\n",
497			    cmd->name);
498			return;
499		}
500#endif
501		/*
502		 * Execute the command.
503		 */
504		if (dopager)
505			db_enable_pager();
506		else
507			db_disable_pager();
508		(*cmd->fcn)(addr, have_addr, count, modif);
509		if (dopager)
510			db_disable_pager();
511
512		if (cmd->flag & CS_SET_DOT) {
513			/*
514			 * If command changes dot, set dot to previous address
515			 * displayed (if 'ed' style).
516			 */
517			db_dot = db_ed_style ? db_prev : db_next;
518		} else {
519			/*
520			 * If command does not change dot, set 'next' location
521			 * to be the same.
522			 */
523			db_next = db_dot;
524		}
525	}
526}
527
528/*
529 * At least one non-optional command must be implemented using
530 * DB_COMMAND() so that db_cmd_set gets created.  Here is one.
531 */
532DB_COMMAND_FLAGS(panic, db_panic, DB_CMD_MEMSAFE)
533{
534	db_disable_pager();
535	panic("from debugger");
536}
537
538void
539db_command_loop(void)
540{
541	/*
542	 * Initialize 'prev' and 'next' to dot.
543	 */
544	db_prev = db_dot;
545	db_next = db_dot;
546
547	db_cmd_loop_done = 0;
548	while (!db_cmd_loop_done) {
549		if (db_print_position() != 0)
550			db_printf("\n");
551
552		db_printf("db> ");
553		(void)db_read_line();
554
555		db_command(&db_last_command, &db_cmd_table, /* dopager */ true);
556	}
557}
558
559/*
560 * Execute a command on behalf of a script.  The caller is responsible for
561 * making sure that the command string is < DB_MAXLINE or it will be
562 * truncated.
563 *
564 * XXXRW: Runs by injecting faked input into DDB input stream; it would be
565 * nicer to use an alternative approach that didn't mess with the previous
566 * command buffer.
567 */
568void
569db_command_script(const char *command)
570{
571	db_prev = db_next = db_dot;
572	db_inject_line(command);
573	db_command(&db_last_command, &db_cmd_table, /* dopager */ false);
574}
575
576void
577db_error(const char *s)
578{
579	if (s)
580	    db_printf("%s", s);
581	db_flush_lex();
582	kdb_reenter_silent();
583}
584
585static void
586db_dump(db_expr_t dummy, bool dummy2, db_expr_t dummy3, char *dummy4)
587{
588	int error;
589
590	if (textdump_pending) {
591		db_printf("textdump_pending set.\n"
592		    "run \"textdump unset\" first or \"textdump dump\" for a textdump.\n");
593		return;
594	}
595	error = doadump(false);
596	if (error) {
597		db_printf("Cannot dump: ");
598		switch (error) {
599		case EBUSY:
600			db_printf("debugger got invoked while dumping.\n");
601			break;
602		case ENXIO:
603			db_printf("no dump device specified.\n");
604			break;
605		default:
606			db_printf("unknown error (error=%d).\n", error);
607			break;
608		}
609	}
610}
611
612/*
613 * Call random function:
614 * !expr(arg,arg,arg)
615 */
616
617/* The generic implementation supports a maximum of 10 arguments. */
618typedef db_expr_t __db_f(db_expr_t, db_expr_t, db_expr_t, db_expr_t,
619    db_expr_t, db_expr_t, db_expr_t, db_expr_t, db_expr_t, db_expr_t);
620
621static __inline int
622db_fncall_generic(db_expr_t addr, db_expr_t *rv, int nargs, db_expr_t args[])
623{
624	__db_f *f = (__db_f *)addr;
625
626	if (nargs > 10) {
627		db_printf("Too many arguments (max 10)\n");
628		return (0);
629	}
630	*rv = (*f)(args[0], args[1], args[2], args[3], args[4], args[5],
631	    args[6], args[7], args[8], args[9]);
632	return (1);
633}
634
635static void
636db_fncall(db_expr_t dummy1, bool dummy2, db_expr_t dummy3, char *dummy4)
637{
638	db_expr_t	fn_addr;
639	db_expr_t	args[DB_MAXARGS];
640	int		nargs = 0;
641	db_expr_t	retval;
642	int		t;
643
644	if (!db_expression(&fn_addr)) {
645	    db_printf("Bad function\n");
646	    db_flush_lex();
647	    return;
648	}
649
650	t = db_read_token();
651	if (t == tLPAREN) {
652	    if (db_expression(&args[0])) {
653		nargs++;
654		while ((t = db_read_token()) == tCOMMA) {
655		    if (nargs == DB_MAXARGS) {
656			db_printf("Too many arguments (max %d)\n", DB_MAXARGS);
657			db_flush_lex();
658			return;
659		    }
660		    if (!db_expression(&args[nargs])) {
661			db_printf("Argument missing\n");
662			db_flush_lex();
663			return;
664		    }
665		    nargs++;
666		}
667		db_unread_token(t);
668	    }
669	    if (db_read_token() != tRPAREN) {
670	        db_printf("Mismatched parens\n");
671		db_flush_lex();
672		return;
673	    }
674	}
675	db_skip_to_eol();
676	db_disable_pager();
677
678	if (DB_CALL(fn_addr, &retval, nargs, args))
679		db_printf("= %#lr\n", (long)retval);
680}
681
682static void
683db_halt(db_expr_t dummy, bool dummy2, db_expr_t dummy3, char *dummy4)
684{
685
686	cpu_halt();
687}
688
689static void
690db_kill(db_expr_t dummy1, bool dummy2, db_expr_t dummy3, char *dummy4)
691{
692	db_expr_t old_radix, pid, sig;
693	struct proc *p;
694
695#define	DB_ERROR(f)	do { db_printf f; db_flush_lex(); goto out; } while (0)
696
697	/*
698	 * PIDs and signal numbers are typically represented in base
699	 * 10, so make that the default here.  It can, of course, be
700	 * overridden by specifying a prefix.
701	 */
702	old_radix = db_radix;
703	db_radix = 10;
704	/* Retrieve arguments. */
705	if (!db_expression(&sig))
706		DB_ERROR(("Missing signal number\n"));
707	if (!db_expression(&pid))
708		DB_ERROR(("Missing process ID\n"));
709	db_skip_to_eol();
710	if (!_SIG_VALID(sig))
711		DB_ERROR(("Signal number out of range\n"));
712
713	/*
714	 * Find the process in question.  allproc_lock is not needed
715	 * since we're in DDB.
716	 */
717	/* sx_slock(&allproc_lock); */
718	FOREACH_PROC_IN_SYSTEM(p)
719	    if (p->p_pid == pid)
720		    break;
721	/* sx_sunlock(&allproc_lock); */
722	if (p == NULL)
723		DB_ERROR(("Can't find process with pid %ld\n", (long) pid));
724
725	/* If it's already locked, bail; otherwise, do the deed. */
726	if (PROC_TRYLOCK(p) == 0)
727		DB_ERROR(("Can't lock process with pid %ld\n", (long) pid));
728	else {
729		pksignal(p, sig, NULL);
730		PROC_UNLOCK(p);
731	}
732
733out:
734	db_radix = old_radix;
735#undef DB_ERROR
736}
737
738/*
739 * Reboot.  In case there is an additional argument, take it as delay in
740 * seconds.  Default to 15s if we cannot parse it and make sure we will
741 * never wait longer than 1 week.  Some code is similar to
742 * kern_shutdown.c:shutdown_panic().
743 */
744#ifndef	DB_RESET_MAXDELAY
745#define	DB_RESET_MAXDELAY	(3600 * 24 * 7)
746#endif
747
748static void
749db_reset(db_expr_t addr, bool have_addr, db_expr_t count __unused,
750    char *modif)
751{
752	int delay, loop;
753
754	if (have_addr) {
755		delay = (int)db_hex2dec(addr);
756
757		/* If we parse to fail, use 15s. */
758		if (delay == -1)
759			delay = 15;
760
761		/* Cap at one week. */
762		if ((uintmax_t)delay > (uintmax_t)DB_RESET_MAXDELAY)
763			delay = DB_RESET_MAXDELAY;
764
765		db_printf("Automatic reboot in %d seconds - "
766		    "press a key on the console to abort\n", delay);
767		for (loop = delay * 10; loop > 0; --loop) {
768			DELAY(1000 * 100); /* 1/10th second */
769			/* Did user type a key? */
770			if (cncheckc() != -1)
771				return;
772		}
773	}
774
775	/*
776	 * Conditionally try the standard reboot path, so any registered
777	 * shutdown/reset handlers have a chance to run first. Some platforms
778	 * may not support the machine-dependent mechanism used by cpu_reset()
779	 * and rely on some other non-standard mechanism to perform the reset.
780	 * For example, the BCM2835 watchdog driver or gpio-poweroff driver.
781	 */
782	if (modif[0] != 's') {
783		kern_reboot(RB_NOSYNC);
784		/* NOTREACHED */
785	}
786
787	cpu_reset();
788}
789
790static void
791db_watchdog(db_expr_t dummy1, bool dummy2, db_expr_t dummy3, char *dummy4)
792{
793	db_expr_t old_radix, tout;
794	int err, i;
795
796	old_radix = db_radix;
797	db_radix = 10;
798	err = db_expression(&tout);
799	db_skip_to_eol();
800	db_radix = old_radix;
801
802	/* If no argument is provided the watchdog will just be disabled. */
803	if (err == 0) {
804		db_printf("No argument provided, disabling watchdog\n");
805		tout = 0;
806	} else if ((tout & WD_INTERVAL) == WD_TO_NEVER) {
807		db_error("Out of range watchdog interval\n");
808		return;
809	}
810	EVENTHANDLER_INVOKE(watchdog_list, tout, &i);
811}
812
813static void
814db_gdb(db_expr_t dummy1, bool dummy2, db_expr_t dummy3, char *dummy4)
815{
816
817	if (kdb_dbbe_select("gdb") != 0) {
818		db_printf("The remote GDB backend could not be selected.\n");
819		return;
820	}
821	/*
822	 * Mark that we are done in the debugger.  kdb_trap()
823	 * should re-enter with the new backend.
824	 */
825	db_cmd_loop_done = 1;
826	db_printf("(ctrl-c will return control to ddb)\n");
827}
828
829static void
830db_stack_trace(db_expr_t tid, bool hastid, db_expr_t count, char *modif)
831{
832	struct thread *td;
833	db_expr_t radix;
834	pid_t pid;
835	int t;
836
837	/*
838	 * We parse our own arguments. We don't like the default radix.
839	 */
840	radix = db_radix;
841	db_radix = 10;
842	hastid = db_expression(&tid);
843	t = db_read_token();
844	if (t == tCOMMA) {
845		if (!db_expression(&count)) {
846			db_printf("Count missing\n");
847			db_flush_lex();
848			db_radix = radix;
849			return;
850		}
851	} else {
852		db_unread_token(t);
853		count = -1;
854	}
855	db_skip_to_eol();
856	db_radix = radix;
857
858	if (hastid) {
859		td = kdb_thr_lookup((lwpid_t)tid);
860		if (td == NULL)
861			td = kdb_thr_from_pid((pid_t)tid);
862		if (td == NULL) {
863			db_printf("Thread %d not found\n", (int)tid);
864			return;
865		}
866	} else
867		td = kdb_thread;
868	if (td->td_proc != NULL)
869		pid = td->td_proc->p_pid;
870	else
871		pid = -1;
872	db_printf("Tracing pid %d tid %ld td %p\n", pid, (long)td->td_tid, td);
873	if (td->td_proc != NULL && (td->td_proc->p_flag & P_INMEM) == 0)
874		db_printf("--- swapped out\n");
875	else
876		db_trace_thread(td, count);
877}
878
879static void
880_db_stack_trace_all(bool active_only)
881{
882	struct thread *td;
883	jmp_buf jb;
884	void *prev_jb;
885
886	for (td = kdb_thr_first(); td != NULL; td = kdb_thr_next(td)) {
887		prev_jb = kdb_jmpbuf(jb);
888		if (setjmp(jb) == 0) {
889			if (TD_IS_RUNNING(td))
890				db_printf("\nTracing command %s pid %d"
891				    " tid %ld td %p (CPU %d)\n",
892				    td->td_proc->p_comm, td->td_proc->p_pid,
893				    (long)td->td_tid, td, td->td_oncpu);
894			else if (active_only)
895				continue;
896			else
897				db_printf("\nTracing command %s pid %d"
898				    " tid %ld td %p\n", td->td_proc->p_comm,
899				    td->td_proc->p_pid, (long)td->td_tid, td);
900			if (td->td_proc->p_flag & P_INMEM)
901				db_trace_thread(td, -1);
902			else
903				db_printf("--- swapped out\n");
904			if (db_pager_quit) {
905				kdb_jmpbuf(prev_jb);
906				return;
907			}
908		}
909		kdb_jmpbuf(prev_jb);
910	}
911}
912
913static void
914db_stack_trace_active(db_expr_t dummy, bool dummy2, db_expr_t dummy3,
915    char *dummy4)
916{
917
918	_db_stack_trace_all(true);
919}
920
921static void
922db_stack_trace_all(db_expr_t dummy, bool dummy2, db_expr_t dummy3,
923    char *dummy4)
924{
925
926	_db_stack_trace_all(false);
927}
928
929/*
930 * Take the parsed expression value from the command line that was parsed
931 * as a hexadecimal value and convert it as if the expression was parsed
932 * as a decimal value.  Returns -1 if the expression was not a valid
933 * decimal value.
934 */
935db_expr_t
936db_hex2dec(db_expr_t expr)
937{
938	uintptr_t x, y;
939	db_expr_t val;
940
941	y = 1;
942	val = 0;
943	x = expr;
944	while (x != 0) {
945		if (x % 16 > 9)
946			return (-1);
947		val += (x % 16) * (y);
948		x >>= 4;
949		y *= 10;
950	}
951	return (val);
952}
953