xref: /freebsd/sys/ddb/db_command.c (revision 1838dec31895fd4752fa8631322ab93be0705a66)
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/conf.h>
41 #include <sys/cons.h>
42 #include <sys/eventhandler.h>
43 #include <sys/kdb.h>
44 #include <sys/kernel.h>
45 #include <sys/linker_set.h>
46 #include <sys/lock.h>
47 #include <sys/mutex.h>
48 #include <sys/proc.h>
49 #include <sys/reboot.h>
50 #include <sys/signalvar.h>
51 #include <sys/systm.h>
52 #include <sys/watchdog.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 #include <security/mac/mac_framework.h>
63 
64 /*
65  * Exported global variables
66  */
67 int		db_cmd_loop_done;
68 db_addr_t	db_dot;
69 db_addr_t	db_last_addr;
70 db_addr_t	db_prev;
71 db_addr_t	db_next;
72 
73 static db_cmdfcn_t	db_dump;
74 static db_cmdfcn_t	db_fncall;
75 static db_cmdfcn_t	db_gdb;
76 static db_cmdfcn_t	db_halt;
77 static db_cmdfcn_t	db_kill;
78 static db_cmdfcn_t	db_reset;
79 static db_cmdfcn_t	db_stack_trace;
80 static db_cmdfcn_t	db_stack_trace_active;
81 static db_cmdfcn_t	db_stack_trace_all;
82 static db_cmdfcn_t	db_watchdog;
83 
84 #define	DB_CMD(_name, _func, _flags)	\
85 {					\
86 	.name =	(_name),		\
87 	.fcn =	(_func),		\
88 	.flag =	(_flags),		\
89 	.more = NULL,			\
90 }
91 #define	DB_TABLE(_name, _more)		\
92 {					\
93 	.name =	(_name),		\
94 	.fcn =	NULL,			\
95 	.more =	(_more),		\
96 }
97 
98 static struct db_command db_show_active_cmds[] = {
99 	DB_CMD("trace",		db_stack_trace_active,	DB_CMD_MEMSAFE),
100 };
101 struct db_command_table db_show_active_table =
102     LIST_HEAD_INITIALIZER(db_show_active_table);
103 
104 static struct db_command db_show_all_cmds[] = {
105 	DB_CMD("trace",		db_stack_trace_all,	DB_CMD_MEMSAFE),
106 };
107 struct db_command_table db_show_all_table =
108     LIST_HEAD_INITIALIZER(db_show_all_table);
109 
110 static struct db_command db_show_cmds[] = {
111 	DB_TABLE("active",	&db_show_active_table),
112 	DB_TABLE("all",		&db_show_all_table),
113 	DB_CMD("registers",	db_show_regs,		DB_CMD_MEMSAFE),
114 	DB_CMD("breaks",	db_listbreak_cmd,	DB_CMD_MEMSAFE),
115 	DB_CMD("threads",	db_show_threads,	DB_CMD_MEMSAFE),
116 };
117 struct db_command_table db_show_table = LIST_HEAD_INITIALIZER(db_show_table);
118 
119 static struct db_command db_cmds[] = {
120 	DB_TABLE("show",	&db_show_table),
121 	DB_CMD("print",		db_print_cmd,		0),
122 	DB_CMD("p",		db_print_cmd,		0),
123 	DB_CMD("examine",	db_examine_cmd,		CS_SET_DOT),
124 	DB_CMD("x",		db_examine_cmd,		CS_SET_DOT),
125 	DB_CMD("search",	db_search_cmd,		CS_OWN|CS_SET_DOT),
126 	DB_CMD("set",		db_set_cmd,		CS_OWN|DB_CMD_MEMSAFE),
127 	DB_CMD("write",		db_write_cmd,		CS_MORE|CS_SET_DOT),
128 	DB_CMD("w",		db_write_cmd,		CS_MORE|CS_SET_DOT),
129 	DB_CMD("delete",	db_delete_cmd,		0),
130 	DB_CMD("d",		db_delete_cmd,		0),
131 	DB_CMD("dump",		db_dump,		DB_CMD_MEMSAFE),
132 	DB_CMD("break",		db_breakpoint_cmd,	0),
133 	DB_CMD("b",		db_breakpoint_cmd,	0),
134 	DB_CMD("dwatch",	db_deletewatch_cmd,	0),
135 	DB_CMD("watch",		db_watchpoint_cmd,	CS_MORE),
136 	DB_CMD("dhwatch",	db_deletehwatch_cmd,	0),
137 	DB_CMD("hwatch",	db_hwatchpoint_cmd,	0),
138 	DB_CMD("step",		db_single_step_cmd,	DB_CMD_MEMSAFE),
139 	DB_CMD("s",		db_single_step_cmd,	DB_CMD_MEMSAFE),
140 	DB_CMD("continue",	db_continue_cmd,	DB_CMD_MEMSAFE),
141 	DB_CMD("c",		db_continue_cmd,	DB_CMD_MEMSAFE),
142 	DB_CMD("until",		db_trace_until_call_cmd, DB_CMD_MEMSAFE),
143 	DB_CMD("next",		db_trace_until_matching_cmd, DB_CMD_MEMSAFE),
144 	DB_CMD("match",		db_trace_until_matching_cmd, 0),
145 	DB_CMD("trace",		db_stack_trace,		CS_OWN|DB_CMD_MEMSAFE),
146 	DB_CMD("t",		db_stack_trace,		CS_OWN|DB_CMD_MEMSAFE),
147 	/* XXX alias for active trace */
148 	DB_CMD("acttrace",	db_stack_trace_active,	DB_CMD_MEMSAFE),
149 	/* XXX alias for all trace */
150 	DB_CMD("alltrace",	db_stack_trace_all,	DB_CMD_MEMSAFE),
151 	DB_CMD("where",		db_stack_trace,		CS_OWN|DB_CMD_MEMSAFE),
152 	DB_CMD("bt",		db_stack_trace,		CS_OWN|DB_CMD_MEMSAFE),
153 	DB_CMD("call",		db_fncall,		CS_OWN),
154 	DB_CMD("ps",		db_ps,			DB_CMD_MEMSAFE),
155 	DB_CMD("gdb",		db_gdb,			0),
156 	DB_CMD("halt",		db_halt,		DB_CMD_MEMSAFE),
157 	DB_CMD("reboot",	db_reset,		DB_CMD_MEMSAFE),
158 	DB_CMD("reset",		db_reset,		DB_CMD_MEMSAFE),
159 	DB_CMD("kill",		db_kill,		CS_OWN|DB_CMD_MEMSAFE),
160 	DB_CMD("watchdog",	db_watchdog,		CS_OWN|DB_CMD_MEMSAFE),
161 	DB_CMD("thread",	db_set_thread,		0),
162 	DB_CMD("run",		db_run_cmd,		CS_OWN|DB_CMD_MEMSAFE),
163 	DB_CMD("script",	db_script_cmd,		CS_OWN|DB_CMD_MEMSAFE),
164 	DB_CMD("scripts",	db_scripts_cmd,		DB_CMD_MEMSAFE),
165 	DB_CMD("unscript",	db_unscript_cmd,	CS_OWN|DB_CMD_MEMSAFE),
166 	DB_CMD("capture",	db_capture_cmd,		CS_OWN|DB_CMD_MEMSAFE),
167 	DB_CMD("textdump",	db_textdump_cmd,	CS_OWN|DB_CMD_MEMSAFE),
168 	DB_CMD("findstack",	db_findstack_cmd,	0),
169 };
170 struct db_command_table db_cmd_table = LIST_HEAD_INITIALIZER(db_cmd_table);
171 
172 #undef DB_CMD
173 #undef DB_TABLE
174 
175 static struct db_command *db_last_command = NULL;
176 
177 /*
178  * if 'ed' style: 'dot' is set at start of last item printed,
179  * and '+' points to next line.
180  * Otherwise: 'dot' points to next item, '..' points to last.
181  */
182 static bool	db_ed_style = true;
183 
184 /*
185  * Utility routine - discard tokens through end-of-line.
186  */
187 void
188 db_skip_to_eol(void)
189 {
190 	int t;
191 
192 	do {
193 		t = db_read_token();
194 	} while (t != tEOL);
195 }
196 
197 /*
198  * Results of command search.
199  */
200 #define	CMD_UNIQUE	0
201 #define	CMD_FOUND	1
202 #define	CMD_NONE	2
203 #define	CMD_AMBIGUOUS	3
204 #define	CMD_HELP	4
205 
206 static void	db_cmd_match(char *name, struct db_command *cmd,
207 		    struct db_command **cmdp, int *resultp);
208 static void	db_cmd_list(struct db_command_table *table);
209 static int	db_cmd_search(char *name, struct db_command_table *table,
210 		    struct db_command **cmdp);
211 static void	db_command(struct db_command **last_cmdp,
212 		    struct db_command_table *cmd_table, bool dopager);
213 
214 /*
215  * Initialize the command lists from the static tables.
216  */
217 void
218 db_command_init(void)
219 {
220 	int i;
221 
222 	for (i = 0; i < nitems(db_cmds); i++)
223 		db_command_register(&db_cmd_table, &db_cmds[i]);
224 	for (i = 0; i < nitems(db_show_cmds); i++)
225 		db_command_register(&db_show_table, &db_show_cmds[i]);
226 	for (i = 0; i < nitems(db_show_active_cmds); i++)
227 		db_command_register(&db_show_active_table,
228 		    &db_show_active_cmds[i]);
229 	for (i = 0; i < nitems(db_show_all_cmds); i++)
230 		db_command_register(&db_show_all_table, &db_show_all_cmds[i]);
231 }
232 
233 /*
234  * Register a command.
235  */
236 void
237 db_command_register(struct db_command_table *list, struct db_command *cmd)
238 {
239 	struct db_command *c, *last;
240 
241 #ifdef MAC
242 	if (mac_ddb_command_register(list, cmd)) {
243 		printf("%s: MAC policy refused registration of command %s\n",
244 		    __func__, cmd->name);
245 		return;
246 	}
247 #endif
248 	last = NULL;
249 	LIST_FOREACH(c, list, next) {
250 		int n = strcmp(cmd->name, c->name);
251 
252 		/* Check that the command is not already present. */
253 		if (n == 0) {
254 			printf("%s: Warning, the command \"%s\" already exists;"
255 			     " ignoring request\n", __func__, cmd->name);
256 			return;
257 		}
258 		if (n < 0) {
259 			/* NB: keep list sorted lexicographically */
260 			LIST_INSERT_BEFORE(c, cmd, next);
261 			return;
262 		}
263 		last = c;
264 	}
265 	if (last == NULL)
266 		LIST_INSERT_HEAD(list, cmd, next);
267 	else
268 		LIST_INSERT_AFTER(last, cmd, next);
269 }
270 
271 /*
272  * Remove a command previously registered with db_command_register.
273  */
274 void
275 db_command_unregister(struct db_command_table *list, struct db_command *cmd)
276 {
277 	struct db_command *c;
278 
279 	LIST_FOREACH(c, list, next) {
280 		if (cmd == c) {
281 			LIST_REMOVE(cmd, next);
282 			return;
283 		}
284 	}
285 	/* NB: intentionally quiet */
286 }
287 
288 /*
289  * Helper function to match a single command.
290  */
291 static void
292 db_cmd_match(char *name, struct db_command *cmd, struct db_command **cmdp,
293     int *resultp)
294 {
295 	char *lp, *rp;
296 	int c;
297 
298 	lp = name;
299 	rp = cmd->name;
300 	while ((c = *lp) == *rp) {
301 		if (c == 0) {
302 			/* complete match */
303 			*cmdp = cmd;
304 			*resultp = CMD_UNIQUE;
305 			return;
306 		}
307 		lp++;
308 		rp++;
309 	}
310 	if (c == 0) {
311 		/* end of name, not end of command -
312 		   partial match */
313 		if (*resultp == CMD_FOUND) {
314 			*resultp = CMD_AMBIGUOUS;
315 			/* but keep looking for a full match -
316 			   this lets us match single letters */
317 		} else if (*resultp == CMD_NONE) {
318 			*cmdp = cmd;
319 			*resultp = CMD_FOUND;
320 		}
321 	}
322 }
323 
324 /*
325  * Search for command prefix.
326  */
327 static int
328 db_cmd_search(char *name, struct db_command_table *table,
329     struct db_command **cmdp)
330 {
331 	struct db_command *cmd;
332 	int result = CMD_NONE;
333 
334 	LIST_FOREACH(cmd, table, next) {
335 		db_cmd_match(name,cmd,cmdp,&result);
336 		if (result == CMD_UNIQUE)
337 			break;
338 	}
339 
340 	if (result == CMD_NONE) {
341 		/* check for 'help' */
342 		if (name[0] == 'h' && name[1] == 'e'
343 		    && name[2] == 'l' && name[3] == 'p')
344 			result = CMD_HELP;
345 	}
346 	return (result);
347 }
348 
349 static void
350 db_cmd_list(struct db_command_table *table)
351 {
352 	struct db_command *cmd;
353 	int have_subcommands;
354 
355 	have_subcommands = 0;
356 	LIST_FOREACH(cmd, table, next) {
357 		if (cmd->more != NULL)
358 			have_subcommands++;
359 		db_printf("%-16s", cmd->name);
360 		db_end_line(16);
361 	}
362 
363 	if (have_subcommands > 0) {
364 		db_printf("\nThe following have subcommands; append \"help\" "
365 		    "to list (e.g. \"show help\"):\n");
366 		LIST_FOREACH(cmd, table, next) {
367 			if (cmd->more == NULL)
368 				continue;
369 			db_printf("%-16s", cmd->name);
370 			db_end_line(16);
371 		}
372 	}
373 }
374 
375 static void
376 db_command(struct db_command **last_cmdp, struct db_command_table *cmd_table,
377     bool dopager)
378 {
379 	char modif[TOK_STRING_SIZE];
380 	struct db_command *cmd = NULL;
381 	db_expr_t addr, count;
382 	int t, result;
383 	bool have_addr = false;
384 
385 	t = db_read_token();
386 	if (t == tEOL) {
387 		/* empty line repeats last command, at 'next' */
388 		cmd = *last_cmdp;
389 		addr = (db_expr_t)db_next;
390 		have_addr = false;
391 		count = 1;
392 		modif[0] = '\0';
393 	} else if (t == tEXCL) {
394 		db_fncall((db_expr_t)0, false, (db_expr_t)0, NULL);
395 		return;
396 	} else if (t != tIDENT) {
397 		db_printf("Unrecognized input; use \"help\" "
398 	            "to list available commands\n");
399 		db_flush_lex();
400 		return;
401 	} else {
402 		/*
403 		 * Search for command
404 		 */
405 		while (cmd_table != NULL) {
406 			result = db_cmd_search(db_tok_string, cmd_table, &cmd);
407 			switch (result) {
408 			case CMD_NONE:
409 				db_printf("No such command; use \"help\" "
410 				    "to list available commands\n");
411 				db_flush_lex();
412 				return;
413 			case CMD_AMBIGUOUS:
414 				db_printf("Ambiguous\n");
415 				db_flush_lex();
416 				return;
417 			case CMD_HELP:
418 				if (cmd_table == &db_cmd_table) {
419 					db_printf("This is ddb(4), the kernel debugger; "
420 					    "see https://man.FreeBSD.org/ddb/4 for help.\n");
421 					db_printf("Use \"bt\" for backtrace, \"dump\" for "
422 					    "kernel core dump, \"reset\" to reboot.\n");
423 					db_printf("Available commands:\n");
424 				}
425 				db_cmd_list(cmd_table);
426 				db_flush_lex();
427 				return;
428 			case CMD_UNIQUE:
429 			case CMD_FOUND:
430 				break;
431 			}
432 			if ((cmd_table = cmd->more) != NULL) {
433 				t = db_read_token();
434 				if (t != tIDENT) {
435 					db_printf("Subcommand required; "
436 					    "available subcommands:\n");
437 					db_cmd_list(cmd_table);
438 					db_flush_lex();
439 					return;
440 				}
441 			}
442 		}
443 
444 		if ((cmd->flag & CS_OWN) == 0) {
445 			/*
446 			 * Standard syntax:
447 			 * command [/modifier] [addr] [,count]
448 			 */
449 			t = db_read_token();
450 			if (t == tSLASH) {
451 				t = db_read_token();
452 				if (t != tIDENT) {
453 					db_printf("Bad modifier\n");
454 					db_flush_lex();
455 					return;
456 				}
457 				db_strcpy(modif, db_tok_string);
458 			} else {
459 				db_unread_token(t);
460 				modif[0] = '\0';
461 			}
462 
463 			if (db_expression(&addr)) {
464 				db_dot = (db_addr_t) addr;
465 				db_last_addr = db_dot;
466 				have_addr = true;
467 			} else {
468 				addr = (db_expr_t) db_dot;
469 				have_addr = false;
470 			}
471 
472 			t = db_read_token();
473 			if (t == tCOMMA) {
474 				if (!db_expression(&count)) {
475 					db_printf("Count missing\n");
476 					db_flush_lex();
477 					return;
478 				}
479 			} else {
480 				db_unread_token(t);
481 				count = -1;
482 			}
483 
484 			if ((cmd->flag & CS_MORE) == 0) {
485 				db_skip_to_eol();
486 			}
487 		}
488 	}
489 
490 	*last_cmdp = cmd;
491 	if (cmd != NULL) {
492 #ifdef MAC
493 		if (mac_ddb_command_exec(cmd, addr, have_addr, count, modif)) {
494 			db_printf("MAC prevented execution of command %s\n",
495 			    cmd->name);
496 			return;
497 		}
498 #endif
499 		/*
500 		 * Execute the command.
501 		 */
502 		if (dopager)
503 			db_enable_pager();
504 		else
505 			db_disable_pager();
506 		(*cmd->fcn)(addr, have_addr, count, modif);
507 		if (dopager)
508 			db_disable_pager();
509 
510 		if (cmd->flag & CS_SET_DOT) {
511 			/*
512 			 * If command changes dot, set dot to previous address
513 			 * displayed (if 'ed' style).
514 			 */
515 			db_dot = db_ed_style ? db_prev : db_next;
516 		} else {
517 			/*
518 			 * If command does not change dot, set 'next' location
519 			 * to be the same.
520 			 */
521 			db_next = db_dot;
522 		}
523 	}
524 }
525 
526 /*
527  * At least one non-optional command must be implemented using
528  * DB_COMMAND() so that db_cmd_set gets created.  Here is one.
529  */
530 DB_COMMAND_FLAGS(panic, db_panic, DB_CMD_MEMSAFE)
531 {
532 	db_disable_pager();
533 	panic("from debugger");
534 }
535 
536 void
537 db_command_loop(void)
538 {
539 	/*
540 	 * Initialize 'prev' and 'next' to dot.
541 	 */
542 	db_prev = db_dot;
543 	db_next = db_dot;
544 
545 	db_cmd_loop_done = 0;
546 	while (!db_cmd_loop_done) {
547 		if (db_print_position() != 0)
548 			db_printf("\n");
549 
550 		db_printf("db> ");
551 		(void)db_read_line();
552 
553 		db_command(&db_last_command, &db_cmd_table, /* dopager */ true);
554 	}
555 }
556 
557 /*
558  * Execute a command on behalf of a script.  The caller is responsible for
559  * making sure that the command string is < DB_MAXLINE or it will be
560  * truncated.
561  *
562  * XXXRW: Runs by injecting faked input into DDB input stream; it would be
563  * nicer to use an alternative approach that didn't mess with the previous
564  * command buffer.
565  */
566 void
567 db_command_script(const char *command)
568 {
569 	db_prev = db_next = db_dot;
570 	db_inject_line(command);
571 	db_command(&db_last_command, &db_cmd_table, /* dopager */ false);
572 }
573 
574 void
575 db_error(const char *s)
576 {
577 	if (s)
578 	    db_printf("%s", s);
579 	db_flush_lex();
580 	kdb_reenter_silent();
581 }
582 
583 static void
584 db_dump(db_expr_t dummy, bool dummy2, db_expr_t dummy3, char *dummy4)
585 {
586 	int error;
587 
588 	if (textdump_pending) {
589 		db_printf("textdump_pending set.\n"
590 		    "run \"textdump unset\" first or \"textdump dump\" for a textdump.\n");
591 		return;
592 	}
593 	error = doadump(false);
594 	if (error) {
595 		db_printf("Cannot dump: ");
596 		switch (error) {
597 		case EBUSY:
598 			db_printf("debugger got invoked while dumping.\n");
599 			break;
600 		case ENXIO:
601 			db_printf("no dump device specified.\n");
602 			break;
603 		default:
604 			db_printf("unknown error (error=%d).\n", error);
605 			break;
606 		}
607 	}
608 }
609 
610 /*
611  * Call random function:
612  * !expr(arg,arg,arg)
613  */
614 
615 /* The generic implementation supports a maximum of 10 arguments. */
616 typedef db_expr_t __db_f(db_expr_t, db_expr_t, db_expr_t, db_expr_t,
617     db_expr_t, db_expr_t, db_expr_t, db_expr_t, db_expr_t, db_expr_t);
618 
619 static __inline int
620 db_fncall_generic(db_expr_t addr, db_expr_t *rv, int nargs, db_expr_t args[])
621 {
622 	__db_f *f = (__db_f *)addr;
623 
624 	if (nargs > 10) {
625 		db_printf("Too many arguments (max 10)\n");
626 		return (0);
627 	}
628 	*rv = (*f)(args[0], args[1], args[2], args[3], args[4], args[5],
629 	    args[6], args[7], args[8], args[9]);
630 	return (1);
631 }
632 
633 static void
634 db_fncall(db_expr_t dummy1, bool dummy2, db_expr_t dummy3, char *dummy4)
635 {
636 	db_expr_t	fn_addr;
637 	db_expr_t	args[DB_MAXARGS];
638 	int		nargs = 0;
639 	db_expr_t	retval;
640 	int		t;
641 
642 	if (!db_expression(&fn_addr)) {
643 	    db_printf("Bad function\n");
644 	    db_flush_lex();
645 	    return;
646 	}
647 
648 	t = db_read_token();
649 	if (t == tLPAREN) {
650 	    if (db_expression(&args[0])) {
651 		nargs++;
652 		while ((t = db_read_token()) == tCOMMA) {
653 		    if (nargs == DB_MAXARGS) {
654 			db_printf("Too many arguments (max %d)\n", DB_MAXARGS);
655 			db_flush_lex();
656 			return;
657 		    }
658 		    if (!db_expression(&args[nargs])) {
659 			db_printf("Argument missing\n");
660 			db_flush_lex();
661 			return;
662 		    }
663 		    nargs++;
664 		}
665 		db_unread_token(t);
666 	    }
667 	    if (db_read_token() != tRPAREN) {
668 	        db_printf("Mismatched parens\n");
669 		db_flush_lex();
670 		return;
671 	    }
672 	}
673 	db_skip_to_eol();
674 	db_disable_pager();
675 
676 	if (DB_CALL(fn_addr, &retval, nargs, args))
677 		db_printf("= %#lr\n", (long)retval);
678 }
679 
680 static void
681 db_halt(db_expr_t dummy, bool dummy2, db_expr_t dummy3, char *dummy4)
682 {
683 
684 	cpu_halt();
685 }
686 
687 static void
688 db_kill(db_expr_t dummy1, bool dummy2, db_expr_t dummy3, char *dummy4)
689 {
690 	db_expr_t old_radix, pid, sig;
691 	struct proc *p;
692 
693 #define	DB_ERROR(f)	do { db_printf f; db_flush_lex(); goto out; } while (0)
694 
695 	/*
696 	 * PIDs and signal numbers are typically represented in base
697 	 * 10, so make that the default here.  It can, of course, be
698 	 * overridden by specifying a prefix.
699 	 */
700 	old_radix = db_radix;
701 	db_radix = 10;
702 	/* Retrieve arguments. */
703 	if (!db_expression(&sig))
704 		DB_ERROR(("Missing signal number\n"));
705 	if (!db_expression(&pid))
706 		DB_ERROR(("Missing process ID\n"));
707 	db_skip_to_eol();
708 	if (!_SIG_VALID(sig))
709 		DB_ERROR(("Signal number out of range\n"));
710 
711 	/*
712 	 * Find the process in question.  allproc_lock is not needed
713 	 * since we're in DDB.
714 	 */
715 	/* sx_slock(&allproc_lock); */
716 	FOREACH_PROC_IN_SYSTEM(p)
717 	    if (p->p_pid == pid)
718 		    break;
719 	/* sx_sunlock(&allproc_lock); */
720 	if (p == NULL)
721 		DB_ERROR(("Can't find process with pid %ld\n", (long) pid));
722 
723 	/* If it's already locked, bail; otherwise, do the deed. */
724 	if (PROC_TRYLOCK(p) == 0)
725 		DB_ERROR(("Can't lock process with pid %ld\n", (long) pid));
726 	else {
727 		pksignal(p, sig, NULL);
728 		PROC_UNLOCK(p);
729 	}
730 
731 out:
732 	db_radix = old_radix;
733 #undef DB_ERROR
734 }
735 
736 /*
737  * Reboot.  In case there is an additional argument, take it as delay in
738  * seconds.  Default to 15s if we cannot parse it and make sure we will
739  * never wait longer than 1 week.  Some code is similar to
740  * kern_shutdown.c:shutdown_panic().
741  */
742 #ifndef	DB_RESET_MAXDELAY
743 #define	DB_RESET_MAXDELAY	(3600 * 24 * 7)
744 #endif
745 
746 static void
747 db_reset(db_expr_t addr, bool have_addr, db_expr_t count __unused,
748     char *modif __unused)
749 {
750 	int delay, loop;
751 
752 	if (have_addr) {
753 		delay = (int)db_hex2dec(addr);
754 
755 		/* If we parse to fail, use 15s. */
756 		if (delay == -1)
757 			delay = 15;
758 
759 		/* Cap at one week. */
760 		if ((uintmax_t)delay > (uintmax_t)DB_RESET_MAXDELAY)
761 			delay = DB_RESET_MAXDELAY;
762 
763 		db_printf("Automatic reboot in %d seconds - "
764 		    "press a key on the console to abort\n", delay);
765 		for (loop = delay * 10; loop > 0; --loop) {
766 			DELAY(1000 * 100); /* 1/10th second */
767 			/* Did user type a key? */
768 			if (cncheckc() != -1)
769 				return;
770 		}
771 	}
772 
773 	cpu_reset();
774 }
775 
776 static void
777 db_watchdog(db_expr_t dummy1, bool dummy2, db_expr_t dummy3, char *dummy4)
778 {
779 	db_expr_t old_radix, tout;
780 	int err, i;
781 
782 	old_radix = db_radix;
783 	db_radix = 10;
784 	err = db_expression(&tout);
785 	db_skip_to_eol();
786 	db_radix = old_radix;
787 
788 	/* If no argument is provided the watchdog will just be disabled. */
789 	if (err == 0) {
790 		db_printf("No argument provided, disabling watchdog\n");
791 		tout = 0;
792 	} else if ((tout & WD_INTERVAL) == WD_TO_NEVER) {
793 		db_error("Out of range watchdog interval\n");
794 		return;
795 	}
796 	EVENTHANDLER_INVOKE(watchdog_list, tout, &i);
797 }
798 
799 static void
800 db_gdb(db_expr_t dummy1, bool dummy2, db_expr_t dummy3, char *dummy4)
801 {
802 
803 	if (kdb_dbbe_select("gdb") != 0) {
804 		db_printf("The remote GDB backend could not be selected.\n");
805 		return;
806 	}
807 	/*
808 	 * Mark that we are done in the debugger.  kdb_trap()
809 	 * should re-enter with the new backend.
810 	 */
811 	db_cmd_loop_done = 1;
812 	db_printf("(ctrl-c will return control to ddb)\n");
813 }
814 
815 static void
816 db_stack_trace(db_expr_t tid, bool hastid, db_expr_t count, char *modif)
817 {
818 	struct thread *td;
819 	db_expr_t radix;
820 	pid_t pid;
821 	int t;
822 
823 	/*
824 	 * We parse our own arguments. We don't like the default radix.
825 	 */
826 	radix = db_radix;
827 	db_radix = 10;
828 	hastid = db_expression(&tid);
829 	t = db_read_token();
830 	if (t == tCOMMA) {
831 		if (!db_expression(&count)) {
832 			db_printf("Count missing\n");
833 			db_flush_lex();
834 			db_radix = radix;
835 			return;
836 		}
837 	} else {
838 		db_unread_token(t);
839 		count = -1;
840 	}
841 	db_skip_to_eol();
842 	db_radix = radix;
843 
844 	if (hastid) {
845 		td = kdb_thr_lookup((lwpid_t)tid);
846 		if (td == NULL)
847 			td = kdb_thr_from_pid((pid_t)tid);
848 		if (td == NULL) {
849 			db_printf("Thread %d not found\n", (int)tid);
850 			return;
851 		}
852 	} else
853 		td = kdb_thread;
854 	if (td->td_proc != NULL)
855 		pid = td->td_proc->p_pid;
856 	else
857 		pid = -1;
858 	db_printf("Tracing pid %d tid %ld td %p\n", pid, (long)td->td_tid, td);
859 	if (td->td_proc != NULL && (td->td_proc->p_flag & P_INMEM) == 0)
860 		db_printf("--- swapped out\n");
861 	else
862 		db_trace_thread(td, count);
863 }
864 
865 static void
866 _db_stack_trace_all(bool active_only)
867 {
868 	struct thread *td;
869 	jmp_buf jb;
870 	void *prev_jb;
871 
872 	for (td = kdb_thr_first(); td != NULL; td = kdb_thr_next(td)) {
873 		prev_jb = kdb_jmpbuf(jb);
874 		if (setjmp(jb) == 0) {
875 			if (TD_IS_RUNNING(td))
876 				db_printf("\nTracing command %s pid %d"
877 				    " tid %ld td %p (CPU %d)\n",
878 				    td->td_proc->p_comm, td->td_proc->p_pid,
879 				    (long)td->td_tid, td, td->td_oncpu);
880 			else if (active_only)
881 				continue;
882 			else
883 				db_printf("\nTracing command %s pid %d"
884 				    " tid %ld td %p\n", td->td_proc->p_comm,
885 				    td->td_proc->p_pid, (long)td->td_tid, td);
886 			if (td->td_proc->p_flag & P_INMEM)
887 				db_trace_thread(td, -1);
888 			else
889 				db_printf("--- swapped out\n");
890 			if (db_pager_quit) {
891 				kdb_jmpbuf(prev_jb);
892 				return;
893 			}
894 		}
895 		kdb_jmpbuf(prev_jb);
896 	}
897 }
898 
899 static void
900 db_stack_trace_active(db_expr_t dummy, bool dummy2, db_expr_t dummy3,
901     char *dummy4)
902 {
903 
904 	_db_stack_trace_all(true);
905 }
906 
907 static void
908 db_stack_trace_all(db_expr_t dummy, bool dummy2, db_expr_t dummy3,
909     char *dummy4)
910 {
911 
912 	_db_stack_trace_all(false);
913 }
914 
915 /*
916  * Take the parsed expression value from the command line that was parsed
917  * as a hexadecimal value and convert it as if the expression was parsed
918  * as a decimal value.  Returns -1 if the expression was not a valid
919  * decimal value.
920  */
921 db_expr_t
922 db_hex2dec(db_expr_t expr)
923 {
924 	uintptr_t x, y;
925 	db_expr_t val;
926 
927 	y = 1;
928 	val = 0;
929 	x = expr;
930 	while (x != 0) {
931 		if (x % 16 > 9)
932 			return (-1);
933 		val += (x % 16) * (y);
934 		x >>= 4;
935 		y *= 10;
936 	}
937 	return (val);
938 }
939