xref: /freebsd/sys/ddb/db_command.c (revision 5bd73b51076b5cb5a2c9810f76c1d7ed20c4460e)
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 	{ "findstack",	db_findstack_cmd,	0,	0 },
144 };
145 struct command_table db_cmd_table = LIST_HEAD_INITIALIZER(db_cmd_table);
146 
147 static struct command	*db_last_command = 0;
148 
149 /*
150  * if 'ed' style: 'dot' is set at start of last item printed,
151  * and '+' points to next line.
152  * Otherwise: 'dot' points to next item, '..' points to last.
153  */
154 static boolean_t	db_ed_style = TRUE;
155 
156 /*
157  * Utility routine - discard tokens through end-of-line.
158  */
159 void
160 db_skip_to_eol()
161 {
162 	int	t;
163 	do {
164 	    t = db_read_token();
165 	} while (t != tEOL);
166 }
167 
168 /*
169  * Results of command search.
170  */
171 #define	CMD_UNIQUE	0
172 #define	CMD_FOUND	1
173 #define	CMD_NONE	2
174 #define	CMD_AMBIGUOUS	3
175 #define	CMD_HELP	4
176 
177 static void	db_cmd_match(char *name, struct command *cmd,
178 		    struct command **cmdp, int *resultp);
179 static void	db_cmd_list(struct command_table *table);
180 static int	db_cmd_search(char *name, struct command_table *table,
181 		    struct command **cmdp);
182 static void	db_command(struct command **last_cmdp,
183 		    struct command_table *cmd_table, int dopager);
184 
185 /*
186  * Initialize the command lists from the static tables.
187  */
188 void
189 db_command_init(void)
190 {
191 #define	N(a)	(sizeof(a) / sizeof(a[0]))
192 	int i;
193 
194 	for (i = 0; i < N(db_cmds); i++)
195 		db_command_register(&db_cmd_table, &db_cmds[i]);
196 	for (i = 0; i < N(db_show_cmds); i++)
197 		db_command_register(&db_show_table, &db_show_cmds[i]);
198 	for (i = 0; i < N(db_show_all_cmds); i++)
199 		db_command_register(&db_show_all_table, &db_show_all_cmds[i]);
200 #undef N
201 }
202 
203 /*
204  * Register a command.
205  */
206 void
207 db_command_register(struct command_table *list, struct command *cmd)
208 {
209 	struct command *c, *last;
210 
211 	last = NULL;
212 	LIST_FOREACH(c, list, next) {
213 		int n = strcmp(cmd->name, c->name);
214 
215 		/* Check that the command is not already present. */
216 		if (n == 0) {
217 			printf("%s: Warning, the command \"%s\" already exists;"
218 			     " ignoring request\n", __func__, cmd->name);
219 			return;
220 		}
221 		if (n < 0) {
222 			/* NB: keep list sorted lexicographically */
223 			LIST_INSERT_BEFORE(c, cmd, next);
224 			return;
225 		}
226 		last = c;
227 	}
228 	if (last == NULL)
229 		LIST_INSERT_HEAD(list, cmd, next);
230 	else
231 		LIST_INSERT_AFTER(last, cmd, next);
232 }
233 
234 /*
235  * Remove a command previously registered with db_command_register.
236  */
237 void
238 db_command_unregister(struct command_table *list, struct command *cmd)
239 {
240 	struct command *c;
241 
242 	LIST_FOREACH(c, list, next) {
243 		if (cmd == c) {
244 			LIST_REMOVE(cmd, next);
245 			return;
246 		}
247 	}
248 	/* NB: intentionally quiet */
249 }
250 
251 /*
252  * Helper function to match a single command.
253  */
254 static void
255 db_cmd_match(name, cmd, cmdp, resultp)
256 	char *		name;
257 	struct command	*cmd;
258 	struct command	**cmdp;	/* out */
259 	int *		resultp;
260 {
261 	char *lp, *rp;
262 	int c;
263 
264 	lp = name;
265 	rp = cmd->name;
266 	while ((c = *lp) == *rp) {
267 		if (c == 0) {
268 			/* complete match */
269 			*cmdp = cmd;
270 			*resultp = CMD_UNIQUE;
271 			return;
272 		}
273 		lp++;
274 		rp++;
275 	}
276 	if (c == 0) {
277 		/* end of name, not end of command -
278 		   partial match */
279 		if (*resultp == CMD_FOUND) {
280 			*resultp = CMD_AMBIGUOUS;
281 			/* but keep looking for a full match -
282 			   this lets us match single letters */
283 		} else {
284 			*cmdp = cmd;
285 			*resultp = CMD_FOUND;
286 		}
287 	}
288 }
289 
290 /*
291  * Search for command prefix.
292  */
293 static int
294 db_cmd_search(name, table, cmdp)
295 	char *		name;
296 	struct command_table *table;
297 	struct command	**cmdp;	/* out */
298 {
299 	struct command	*cmd;
300 	int		result = CMD_NONE;
301 
302 	LIST_FOREACH(cmd, table, next) {
303 		db_cmd_match(name,cmd,cmdp,&result);
304 		if (result == CMD_UNIQUE)
305 			break;
306 	}
307 
308 	if (result == CMD_NONE) {
309 		/* check for 'help' */
310 		if (name[0] == 'h' && name[1] == 'e'
311 		    && name[2] == 'l' && name[3] == 'p')
312 			result = CMD_HELP;
313 	}
314 	return (result);
315 }
316 
317 static void
318 db_cmd_list(table)
319 	struct command_table *table;
320 {
321 	register struct command	*cmd;
322 
323 	LIST_FOREACH(cmd, table, next) {
324 		db_printf("%-16s", cmd->name);
325 		db_end_line(16);
326 	}
327 }
328 
329 static void
330 db_command(last_cmdp, cmd_table, dopager)
331 	struct command	**last_cmdp;	/* IN_OUT */
332 	struct command_table *cmd_table;
333 	int dopager;
334 {
335 	struct command	*cmd = NULL;
336 	int		t;
337 	char		modif[TOK_STRING_SIZE];
338 	db_expr_t	addr, count;
339 	boolean_t	have_addr = FALSE;
340 	int		result;
341 
342 	t = db_read_token();
343 	if (t == tEOL) {
344 	    /* empty line repeats last command, at 'next' */
345 	    cmd = *last_cmdp;
346 	    addr = (db_expr_t)db_next;
347 	    have_addr = FALSE;
348 	    count = 1;
349 	    modif[0] = '\0';
350 	}
351 	else if (t == tEXCL) {
352 	    db_fncall((db_expr_t)0, (boolean_t)0, (db_expr_t)0, (char *)0);
353 	    return;
354 	}
355 	else if (t != tIDENT) {
356 	    db_printf("?\n");
357 	    db_flush_lex();
358 	    return;
359 	}
360 	else {
361 	    /*
362 	     * Search for command
363 	     */
364 	    while (cmd_table) {
365 		result = db_cmd_search(db_tok_string,
366 				       cmd_table,
367 				       &cmd);
368 		switch (result) {
369 		    case CMD_NONE:
370 			db_printf("No such command\n");
371 			db_flush_lex();
372 			return;
373 		    case CMD_AMBIGUOUS:
374 			db_printf("Ambiguous\n");
375 			db_flush_lex();
376 			return;
377 		    case CMD_HELP:
378 			db_cmd_list(cmd_table);
379 			db_flush_lex();
380 			return;
381 		    default:
382 			break;
383 		}
384 		if ((cmd_table = cmd->more) != NULL) {
385 		    t = db_read_token();
386 		    if (t != tIDENT) {
387 			db_cmd_list(cmd_table);
388 			db_flush_lex();
389 			return;
390 		    }
391 		}
392 	    }
393 
394 	    if ((cmd->flag & CS_OWN) == 0) {
395 		/*
396 		 * Standard syntax:
397 		 * command [/modifier] [addr] [,count]
398 		 */
399 		t = db_read_token();
400 		if (t == tSLASH) {
401 		    t = db_read_token();
402 		    if (t != tIDENT) {
403 			db_printf("Bad modifier\n");
404 			db_flush_lex();
405 			return;
406 		    }
407 		    db_strcpy(modif, db_tok_string);
408 		}
409 		else {
410 		    db_unread_token(t);
411 		    modif[0] = '\0';
412 		}
413 
414 		if (db_expression(&addr)) {
415 		    db_dot = (db_addr_t) addr;
416 		    db_last_addr = db_dot;
417 		    have_addr = TRUE;
418 		}
419 		else {
420 		    addr = (db_expr_t) db_dot;
421 		    have_addr = FALSE;
422 		}
423 		t = db_read_token();
424 		if (t == tCOMMA) {
425 		    if (!db_expression(&count)) {
426 			db_printf("Count missing\n");
427 			db_flush_lex();
428 			return;
429 		    }
430 		}
431 		else {
432 		    db_unread_token(t);
433 		    count = -1;
434 		}
435 		if ((cmd->flag & CS_MORE) == 0) {
436 		    db_skip_to_eol();
437 		}
438 	    }
439 	}
440 	*last_cmdp = cmd;
441 	if (cmd != 0) {
442 	    /*
443 	     * Execute the command.
444 	     */
445 	    if (dopager)
446 		db_enable_pager();
447 	    else
448 		db_disable_pager();
449 	    (*cmd->fcn)(addr, have_addr, count, modif);
450 	    if (dopager)
451 		db_disable_pager();
452 
453 	    if (cmd->flag & CS_SET_DOT) {
454 		/*
455 		 * If command changes dot, set dot to
456 		 * previous address displayed (if 'ed' style).
457 		 */
458 		if (db_ed_style) {
459 		    db_dot = db_prev;
460 		}
461 		else {
462 		    db_dot = db_next;
463 		}
464 	    }
465 	    else {
466 		/*
467 		 * If command does not change dot,
468 		 * set 'next' location to be the same.
469 		 */
470 		db_next = db_dot;
471 	    }
472 	}
473 }
474 
475 /*
476  * At least one non-optional command must be implemented using
477  * DB_COMMAND() so that db_cmd_set gets created.  Here is one.
478  */
479 DB_COMMAND(panic, db_panic)
480 {
481 	db_disable_pager();
482 	panic("from debugger");
483 }
484 
485 void
486 db_command_loop()
487 {
488 	/*
489 	 * Initialize 'prev' and 'next' to dot.
490 	 */
491 	db_prev = db_dot;
492 	db_next = db_dot;
493 
494 	db_cmd_loop_done = 0;
495 	while (!db_cmd_loop_done) {
496 	    if (db_print_position() != 0)
497 		db_printf("\n");
498 
499 	    db_printf("db> ");
500 	    (void) db_read_line();
501 
502 	    db_command(&db_last_command, &db_cmd_table, /* dopager */ 1);
503 	}
504 }
505 
506 /*
507  * Execute a command on behalf of a script.  The caller is responsible for
508  * making sure that the command string is < DB_MAXLINE or it will be
509  * truncated.
510  *
511  * XXXRW: Runs by injecting faked input into DDB input stream; it would be
512  * nicer to use an alternative approach that didn't mess with the previous
513  * command buffer.
514  */
515 void
516 db_command_script(const char *command)
517 {
518 	db_prev = db_next = db_dot;
519 	db_inject_line(command);
520 	db_command(&db_last_command, &db_cmd_table, /* dopager */ 0);
521 }
522 
523 void
524 db_error(s)
525 	const char *s;
526 {
527 	if (s)
528 	    db_printf("%s", s);
529 	db_flush_lex();
530 	kdb_reenter();
531 }
532 
533 static void
534 db_dump(db_expr_t dummy, boolean_t dummy2, db_expr_t dummy3, char *dummy4)
535 {
536 	int error;
537 
538 	if (textdump_pending) {
539 		db_printf("textdump_pending set.\n"
540 		    "run \"textdump unset\" first or \"textdump dump\" for a textdump.\n");
541 		return;
542 	}
543 	error = doadump(FALSE);
544 	if (error) {
545 		db_printf("Cannot dump: ");
546 		switch (error) {
547 		case EBUSY:
548 			db_printf("debugger got invoked while dumping.\n");
549 			break;
550 		case ENXIO:
551 			db_printf("no dump device specified.\n");
552 			break;
553 		default:
554 			db_printf("unknown error (error=%d).\n", error);
555 			break;
556 		}
557 	}
558 }
559 
560 /*
561  * Call random function:
562  * !expr(arg,arg,arg)
563  */
564 
565 /* The generic implementation supports a maximum of 10 arguments. */
566 typedef db_expr_t __db_f(db_expr_t, db_expr_t, db_expr_t, db_expr_t,
567     db_expr_t, db_expr_t, db_expr_t, db_expr_t, db_expr_t, db_expr_t);
568 
569 static __inline int
570 db_fncall_generic(db_expr_t addr, db_expr_t *rv, int nargs, db_expr_t args[])
571 {
572 	__db_f *f = (__db_f *)addr;
573 
574 	if (nargs > 10) {
575 		db_printf("Too many arguments (max 10)\n");
576 		return (0);
577 	}
578 	*rv = (*f)(args[0], args[1], args[2], args[3], args[4], args[5],
579 	    args[6], args[7], args[8], args[9]);
580 	return (1);
581 }
582 
583 static void
584 db_fncall(dummy1, dummy2, dummy3, dummy4)
585 	db_expr_t	dummy1;
586 	boolean_t	dummy2;
587 	db_expr_t	dummy3;
588 	char *		dummy4;
589 {
590 	db_expr_t	fn_addr;
591 	db_expr_t	args[DB_MAXARGS];
592 	int		nargs = 0;
593 	db_expr_t	retval;
594 	int		t;
595 
596 	if (!db_expression(&fn_addr)) {
597 	    db_printf("Bad function\n");
598 	    db_flush_lex();
599 	    return;
600 	}
601 
602 	t = db_read_token();
603 	if (t == tLPAREN) {
604 	    if (db_expression(&args[0])) {
605 		nargs++;
606 		while ((t = db_read_token()) == tCOMMA) {
607 		    if (nargs == DB_MAXARGS) {
608 			db_printf("Too many arguments (max %d)\n", DB_MAXARGS);
609 			db_flush_lex();
610 			return;
611 		    }
612 		    if (!db_expression(&args[nargs])) {
613 			db_printf("Argument missing\n");
614 			db_flush_lex();
615 			return;
616 		    }
617 		    nargs++;
618 		}
619 		db_unread_token(t);
620 	    }
621 	    if (db_read_token() != tRPAREN) {
622 		db_printf("?\n");
623 		db_flush_lex();
624 		return;
625 	    }
626 	}
627 	db_skip_to_eol();
628 	db_disable_pager();
629 
630 	if (DB_CALL(fn_addr, &retval, nargs, args))
631 		db_printf("= %#lr\n", (long)retval);
632 }
633 
634 static void
635 db_halt(db_expr_t dummy, boolean_t dummy2, db_expr_t dummy3, char *dummy4)
636 {
637 
638 	cpu_halt();
639 }
640 
641 static void
642 db_kill(dummy1, dummy2, dummy3, dummy4)
643 	db_expr_t	dummy1;
644 	boolean_t	dummy2;
645 	db_expr_t	dummy3;
646 	char *		dummy4;
647 {
648 	db_expr_t old_radix, pid, sig;
649 	struct proc *p;
650 
651 #define	DB_ERROR(f)	do { db_printf f; db_flush_lex(); goto out; } while (0)
652 
653 	/*
654 	 * PIDs and signal numbers are typically represented in base
655 	 * 10, so make that the default here.  It can, of course, be
656 	 * overridden by specifying a prefix.
657 	 */
658 	old_radix = db_radix;
659 	db_radix = 10;
660 	/* Retrieve arguments. */
661 	if (!db_expression(&sig))
662 		DB_ERROR(("Missing signal number\n"));
663 	if (!db_expression(&pid))
664 		DB_ERROR(("Missing process ID\n"));
665 	db_skip_to_eol();
666 	if (!_SIG_VALID(sig))
667 		DB_ERROR(("Signal number out of range\n"));
668 
669 	/*
670 	 * Find the process in question.  allproc_lock is not needed
671 	 * since we're in DDB.
672 	 */
673 	/* sx_slock(&allproc_lock); */
674 	FOREACH_PROC_IN_SYSTEM(p)
675 	    if (p->p_pid == pid)
676 		    break;
677 	/* sx_sunlock(&allproc_lock); */
678 	if (p == NULL)
679 		DB_ERROR(("Can't find process with pid %ld\n", (long) pid));
680 
681 	/* If it's already locked, bail; otherwise, do the deed. */
682 	if (PROC_TRYLOCK(p) == 0)
683 		DB_ERROR(("Can't lock process with pid %ld\n", (long) pid));
684 	else {
685 		pksignal(p, sig, NULL);
686 		PROC_UNLOCK(p);
687 	}
688 
689 out:
690 	db_radix = old_radix;
691 #undef DB_ERROR
692 }
693 
694 /*
695  * Reboot.  In case there is an additional argument, take it as delay in
696  * seconds.  Default to 15s if we cannot parse it and make sure we will
697  * never wait longer than 1 week.  Some code is similar to
698  * kern_shutdown.c:shutdown_panic().
699  */
700 #ifndef	DB_RESET_MAXDELAY
701 #define	DB_RESET_MAXDELAY	(3600 * 24 * 7)
702 #endif
703 
704 static void
705 db_reset(db_expr_t addr, boolean_t have_addr, db_expr_t count __unused,
706     char *modif __unused)
707 {
708 	int delay, loop;
709 
710 	if (have_addr) {
711 		delay = (int)db_hex2dec(addr);
712 
713 		/* If we parse to fail, use 15s. */
714 		if (delay == -1)
715 			delay = 15;
716 
717 		/* Cap at one week. */
718 		if ((uintmax_t)delay > (uintmax_t)DB_RESET_MAXDELAY)
719 			delay = DB_RESET_MAXDELAY;
720 
721 		db_printf("Automatic reboot in %d seconds - "
722 		    "press a key on the console to abort\n", delay);
723 		for (loop = delay * 10; loop > 0; --loop) {
724 			DELAY(1000 * 100); /* 1/10th second */
725 			/* Did user type a key? */
726 			if (cncheckc() != -1)
727 				return;
728 		}
729 	}
730 
731 	cpu_reset();
732 }
733 
734 static void
735 db_watchdog(dummy1, dummy2, dummy3, dummy4)
736 	db_expr_t	dummy1;
737 	boolean_t	dummy2;
738 	db_expr_t	dummy3;
739 	char *		dummy4;
740 {
741 	db_expr_t old_radix, tout;
742 	int err, i;
743 
744 	old_radix = db_radix;
745 	db_radix = 10;
746 	err = db_expression(&tout);
747 	db_skip_to_eol();
748 	db_radix = old_radix;
749 
750 	/* If no argument is provided the watchdog will just be disabled. */
751 	if (err == 0) {
752 		db_printf("No argument provided, disabling watchdog\n");
753 		tout = 0;
754 	} else if ((tout & WD_INTERVAL) == WD_TO_NEVER) {
755 		db_error("Out of range watchdog interval\n");
756 		return;
757 	}
758 	EVENTHANDLER_INVOKE(watchdog_list, tout, &i);
759 }
760 
761 static void
762 db_gdb(db_expr_t dummy1, boolean_t dummy2, db_expr_t dummy3, char *dummy4)
763 {
764 
765 	if (kdb_dbbe_select("gdb") != 0) {
766 		db_printf("The remote GDB backend could not be selected.\n");
767 		return;
768 	}
769 	/*
770 	 * Mark that we are done in the debugger.  kdb_trap()
771 	 * should re-enter with the new backend.
772 	 */
773 	db_cmd_loop_done = 1;
774 	db_printf("(ctrl-c will return control to ddb)\n");
775 }
776 
777 static void
778 db_stack_trace(db_expr_t tid, boolean_t hastid, db_expr_t count, char *modif)
779 {
780 	struct thread *td;
781 	db_expr_t radix;
782 	pid_t pid;
783 	int t;
784 
785 	/*
786 	 * We parse our own arguments. We don't like the default radix.
787 	 */
788 	radix = db_radix;
789 	db_radix = 10;
790 	hastid = db_expression(&tid);
791 	t = db_read_token();
792 	if (t == tCOMMA) {
793 		if (!db_expression(&count)) {
794 			db_printf("Count missing\n");
795 			db_flush_lex();
796 			return;
797 		}
798 	} else {
799 		db_unread_token(t);
800 		count = -1;
801 	}
802 	db_skip_to_eol();
803 	db_radix = radix;
804 
805 	if (hastid) {
806 		td = kdb_thr_lookup((lwpid_t)tid);
807 		if (td == NULL)
808 			td = kdb_thr_from_pid((pid_t)tid);
809 		if (td == NULL) {
810 			db_printf("Thread %d not found\n", (int)tid);
811 			return;
812 		}
813 	} else
814 		td = kdb_thread;
815 	if (td->td_proc != NULL)
816 		pid = td->td_proc->p_pid;
817 	else
818 		pid = -1;
819 	db_printf("Tracing pid %d tid %ld td %p\n", pid, (long)td->td_tid, td);
820 	db_trace_thread(td, count);
821 }
822 
823 static void
824 db_stack_trace_all(db_expr_t dummy, boolean_t dummy2, db_expr_t dummy3,
825     char *dummy4)
826 {
827 	struct proc *p;
828 	struct thread *td;
829 	jmp_buf jb;
830 	void *prev_jb;
831 
832 	FOREACH_PROC_IN_SYSTEM(p) {
833 		prev_jb = kdb_jmpbuf(jb);
834 		if (setjmp(jb) == 0) {
835 			FOREACH_THREAD_IN_PROC(p, td) {
836 				db_printf("\nTracing command %s pid %d tid %ld td %p\n",
837 					  p->p_comm, p->p_pid, (long)td->td_tid, td);
838 				db_trace_thread(td, -1);
839 				if (db_pager_quit) {
840 					kdb_jmpbuf(prev_jb);
841 					return;
842 				}
843 			}
844 		}
845 		kdb_jmpbuf(prev_jb);
846 	}
847 }
848 
849 /*
850  * Take the parsed expression value from the command line that was parsed
851  * as a hexadecimal value and convert it as if the expression was parsed
852  * as a decimal value.  Returns -1 if the expression was not a valid
853  * decimal value.
854  */
855 db_expr_t
856 db_hex2dec(db_expr_t expr)
857 {
858 	uintptr_t x, y;
859 	db_expr_t val;
860 
861 	y = 1;
862 	val = 0;
863 	x = expr;
864 	while (x != 0) {
865 		if (x % 16 > 9)
866 			return (-1);
867 		val += (x % 16) * (y);
868 		x >>= 4;
869 		y *= 10;
870 	}
871 	return (val);
872 }
873