xref: /netbsd-src/sys/ddb/db_command.c (revision 4bfc10355ca5ccd94d950ad6f7092be3470193fa)
1 /*	$NetBSD: db_command.c,v 1.131 2009/03/21 13:06:39 ad Exp $	*/
2 
3 /*
4  * Copyright (c) 1996, 1997, 1998, 1999, 2002, 2009 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Adam Hamsik, and by Andrew Doran.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 /*
33  * Mach Operating System
34  * Copyright (c) 1991,1990 Carnegie Mellon University
35  * All Rights Reserved.
36  *
37  * Permission to use, copy, modify and distribute this software and its
38  * documentation is hereby granted, provided that both the copyright
39  * notice and this permission notice appear in all copies of the
40  * software, derivative works or modified versions, and any portions
41  * thereof, and that both notices appear in supporting documentation.
42  *
43  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
44  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
45  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
46  *
47  * Carnegie Mellon requests users of this software to return to
48  *
49  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
50  *  School of Computer Science
51  *  Carnegie Mellon University
52  *  Pittsburgh PA 15213-3890
53  *
54  * any improvements or extensions that they make and grant Carnegie the
55  * rights to redistribute these changes.
56  */
57 
58 /*
59  * Command dispatcher.
60  */
61 
62 #include <sys/cdefs.h>
63 __KERNEL_RCSID(0, "$NetBSD: db_command.c,v 1.131 2009/03/21 13:06:39 ad Exp $");
64 
65 #ifdef _KERNEL_OPT
66 #include "opt_aio.h"
67 #include "opt_ddb.h"
68 #include "opt_kgdb.h"
69 #include "opt_inet.h"
70 #include "opt_uvmhist.h"
71 #include "opt_ddbparam.h"
72 #include "opt_multiprocessor.h"
73 #include "arp.h"
74 #endif
75 
76 #include <sys/param.h>
77 #include <sys/systm.h>
78 #include <sys/reboot.h>
79 #include <sys/device.h>
80 #include <sys/lwp.h>
81 #include <sys/malloc.h>
82 #include <sys/mbuf.h>
83 #include <sys/namei.h>
84 #include <sys/pool.h>
85 #include <sys/proc.h>
86 #include <sys/vnode.h>
87 #include <sys/vmem.h>
88 #include <sys/lockdebug.h>
89 #include <sys/cpu.h>
90 #include <sys/buf.h>
91 #include <sys/module.h>
92 
93 /*include queue macros*/
94 #include <sys/queue.h>
95 
96 #include <ddb/ddb.h>
97 
98 #include <uvm/uvm_extern.h>
99 #include <uvm/uvm_ddb.h>
100 
101 /*
102  * Results of command search.
103  */
104 #define	CMD_EXACT		0
105 #define	CMD_PREFIX		1
106 #define	CMD_NONE		2
107 #define	CMD_AMBIGUOUS	3
108 
109 /*
110  * Exported global variables
111  */
112 bool		db_cmd_loop_done;
113 label_t		*db_recover;
114 db_addr_t	db_dot;
115 db_addr_t	db_last_addr;
116 db_addr_t	db_prev;
117 db_addr_t	db_next;
118 
119 
120 /*
121  * New DDB api for adding and removing commands uses three lists, because
122  * we use two types of commands
123  * a) standard commands without subcommands -> reboot
124  * b) show commands which are subcommands of show command -> show aio_jobs
125  * c) if defined machine specific commands
126  *
127  * ddb_add_cmd, ddb_rem_cmd use type (DDB_SHOW_CMD||DDB_BASE_CMD)argument to
128  * add them to representativ lists.
129  */
130 
131 static const struct db_command db_command_table[];
132 static const struct db_command db_show_cmds[];
133 
134 #ifdef DB_MACHINE_COMMANDS
135 static const struct db_command db_machine_command_table[];
136 #endif
137 
138 /* the global queue of all command tables */
139 TAILQ_HEAD(db_cmd_tbl_en_head, db_cmd_tbl_en);
140 
141 /* TAILQ entry used to register command tables */
142 struct db_cmd_tbl_en {
143 	const struct db_command *db_cmd;	/* cmd table */
144 	TAILQ_ENTRY(db_cmd_tbl_en) db_cmd_next;
145 };
146 
147 /* head of base commands list */
148 static struct db_cmd_tbl_en_head db_base_cmd_list =
149 	TAILQ_HEAD_INITIALIZER(db_base_cmd_list);
150 static struct db_cmd_tbl_en db_base_cmd_builtins =
151      { .db_cmd = db_command_table };
152 
153 /* head of show commands list */
154 static struct db_cmd_tbl_en_head db_show_cmd_list =
155 	TAILQ_HEAD_INITIALIZER(db_show_cmd_list);
156 static struct db_cmd_tbl_en db_show_cmd_builtins =
157      { .db_cmd = db_show_cmds };
158 
159 /* head of machine commands list */
160 static struct db_cmd_tbl_en_head db_mach_cmd_list =
161 	TAILQ_HEAD_INITIALIZER(db_mach_cmd_list);
162 #ifdef DB_MACHINE_COMMANDS
163 static struct db_cmd_tbl_en db_mach_cmd_builtins =
164      { .db_cmd = db_machine_command_table };
165 #endif
166 
167 /*
168  * if 'ed' style: 'dot' is set at start of last item printed,
169  * and '+' points to next line.
170  * Otherwise: 'dot' points to next item, '..' points to last.
171  */
172 static bool	 db_ed_style = true;
173 
174 static void	db_init_commands(void);
175 static int	db_register_tbl_entry(uint8_t type,
176     struct db_cmd_tbl_en *list_ent);
177 static void	db_cmd_list(const struct db_cmd_tbl_en_head *);
178 static int	db_cmd_search(const char *, struct db_cmd_tbl_en_head *,
179 			      const struct db_command **);
180 static int	db_cmd_search_table(const char *, const struct db_command *,
181 				    const struct db_command **);
182 static void	db_cmd_search_failed(char *, int);
183 static const struct db_command *db_read_command(void);
184 static void	db_command(const struct db_command **);
185 static void	db_buf_print_cmd(db_expr_t, bool, db_expr_t, const char *);
186 static void	db_event_print_cmd(db_expr_t, bool, db_expr_t, const char *);
187 static void	db_fncall(db_expr_t, bool, db_expr_t, const char *);
188 static void     db_help_print_cmd(db_expr_t, bool, db_expr_t, const char *);
189 static void	db_lock_print_cmd(db_expr_t, bool, db_expr_t, const char *);
190 static void	db_mount_print_cmd(db_expr_t, bool, db_expr_t, const char *);
191 static void	db_mbuf_print_cmd(db_expr_t, bool, db_expr_t, const char *);
192 static void	db_malloc_print_cmd(db_expr_t, bool, db_expr_t, const char *);
193 static void	db_map_print_cmd(db_expr_t, bool, db_expr_t, const char *);
194 static void	db_namecache_print_cmd(db_expr_t, bool, db_expr_t,
195 		    const char *);
196 static void	db_object_print_cmd(db_expr_t, bool, db_expr_t, const char *);
197 static void	db_page_print_cmd(db_expr_t, bool, db_expr_t, const char *);
198 static void	db_show_all_pages(db_expr_t, bool, db_expr_t, const char *);
199 static void	db_pool_print_cmd(db_expr_t, bool, db_expr_t, const char *);
200 static void	db_reboot_cmd(db_expr_t, bool, db_expr_t, const char *);
201 static void	db_sifting_cmd(db_expr_t, bool, db_expr_t, const char *);
202 static void	db_stack_trace_cmd(db_expr_t, bool, db_expr_t, const char *);
203 static void	db_sync_cmd(db_expr_t, bool, db_expr_t, const char *);
204 static void	db_whatis_cmd(db_expr_t, bool, db_expr_t, const char *);
205 static void	db_uvmexp_print_cmd(db_expr_t, bool, db_expr_t, const char *);
206 #ifdef UVMHIST
207 static void	db_uvmhist_print_cmd(db_expr_t, bool, db_expr_t, const char *);
208 #endif
209 static void	db_vnode_print_cmd(db_expr_t, bool, db_expr_t, const char *);
210 static void	db_vmem_print_cmd(db_expr_t, bool, db_expr_t, const char *);
211 
212 static const struct db_command db_show_cmds[] = {
213 	/*added from all sub cmds*/
214 #ifdef _KERNEL	/* XXX CRASH(8) */
215 	{ DDB_ADD_CMD("callout",  db_show_callout,
216 	    0 ,"List all used callout functions.",NULL,NULL) },
217 #endif
218 	{ DDB_ADD_CMD("pages",	db_show_all_pages,
219 	    0 ,"List all used memory pages.",NULL,NULL) },
220 	{ DDB_ADD_CMD("procs",	db_show_all_procs,
221 	    0 ,"List all processes.",NULL,NULL) },
222 	{ DDB_ADD_CMD("pools",	db_show_all_pools,
223 	    0 ,"Show all poolS",NULL,NULL) },
224 #ifdef AIO
225 	/*added from all sub cmds*/
226 	{ DDB_ADD_CMD("aio_jobs",	db_show_aio_jobs,	0,
227 	    "Show aio jobs",NULL,NULL) },
228 #endif
229 	{ DDB_ADD_CMD("all",	NULL,
230 	    CS_COMPAT, NULL,NULL,NULL) },
231 #if defined(INET) && (NARP > 0)
232 	{ DDB_ADD_CMD("arptab",	db_show_arptab,		0,NULL,NULL,NULL) },
233 #endif
234 #ifdef _KERNEL
235 	{ DDB_ADD_CMD("breaks",	db_listbreak_cmd, 	0,
236 	    "Display all breaks.",NULL,NULL) },
237 #endif
238 	{ DDB_ADD_CMD("buf",	db_buf_print_cmd,	0,
239 	    "Print the struct buf at address.", "[/f] address",NULL) },
240 	{ DDB_ADD_CMD("event",	db_event_print_cmd,	0,
241 	    "Print all the non-zero evcnt(9) event counters.", "[/f]",NULL) },
242 	{ DDB_ADD_CMD("files", db_show_files_cmd,	0,
243 	    "Print the files open by process at address",
244 	    "[/f] address", NULL) },
245 	{ DDB_ADD_CMD("lock",	db_lock_print_cmd,	0,NULL,NULL,NULL) },
246 	{ DDB_ADD_CMD("malloc",	db_malloc_print_cmd,0,NULL,NULL,NULL) },
247 	{ DDB_ADD_CMD("map",	db_map_print_cmd,	0,
248 	    "Print the vm_map at address.", "[/f] address",NULL) },
249 	{ DDB_ADD_CMD("module", db_show_module_cmd,	0,
250 	    "Print kernel modules", NULL, NULL) },
251 	{ DDB_ADD_CMD("mount",	db_mount_print_cmd,	0,
252 	    "Print the mount structure at address.", "[/f] address",NULL) },
253 	{ DDB_ADD_CMD("mqueue", db_show_mqueue_cmd,	0,
254 	    "Print the message queues", NULL, NULL) },
255 	{ DDB_ADD_CMD("mbuf",	db_mbuf_print_cmd,	0,NULL,NULL,
256 	    "-c prints all mbuf chains") },
257 	{ DDB_ADD_CMD("ncache",	db_namecache_print_cmd,	0,
258 	    "Dump the namecache list.", "address",NULL) },
259 	{ DDB_ADD_CMD("object",	db_object_print_cmd,	0,
260 	    "Print the vm_object at address.", "[/f] address",NULL) },
261 	{ DDB_ADD_CMD("page",	db_page_print_cmd,	0,
262 	    "Print the vm_page at address.", "[/f] address",NULL) },
263 	{ DDB_ADD_CMD("pool",	db_pool_print_cmd,	0,
264 	    "Print the pool at address.", "[/clp] address",NULL) },
265 	{ DDB_ADD_CMD("registers",	db_show_regs,		0,
266 	    "Display the register set.", "[/u]",NULL) },
267 	{ DDB_ADD_CMD("sched_qs",	db_show_sched_qs,	0,
268 	    "Print the state of the scheduler's run queues.",
269 	    NULL,NULL) },
270 	{ DDB_ADD_CMD("uvmexp",	db_uvmexp_print_cmd, 0,
271 	    "Print a selection of UVM counters and statistics.",
272 	    NULL,NULL) },
273 #ifdef UVMHIST
274 	{ DDB_ADD_CMD("uvmhist", db_uvmhist_print_cmd, 0,
275 	    "Print the UVM history logs.",
276 	    NULL,NULL) },
277 #endif
278 	{ DDB_ADD_CMD("vnode",	db_vnode_print_cmd,	0,
279 	    "Print the vnode at address.", "[/f] address",NULL) },
280 	{ DDB_ADD_CMD("vmem", db_vmem_print_cmd,	0,
281 	    "Print the vmem usage.", "[/a] address", NULL) },
282 	{ DDB_ADD_CMD("vmems", db_show_all_vmems,	0,
283 	    "Show all vmems.", NULL, NULL) },
284 #ifdef _KERNEL
285 	{ DDB_ADD_CMD("watches",	db_listwatch_cmd, 	0,
286 	    "Display all watchpoints.", NULL,NULL) },
287 #endif
288 	{ DDB_ADD_CMD(NULL,		NULL,			0,NULL,NULL,NULL) }
289 };
290 
291 /* arch/<arch>/<arch>/db_interface.c */
292 #ifdef DB_MACHINE_COMMANDS
293 extern const struct db_command db_machine_command_table[];
294 #endif
295 
296 static const struct db_command db_command_table[] = {
297 	{ DDB_ADD_CMD("b",		db_breakpoint_cmd,	0,
298 	    "Set a breakpoint at address", "[/u] address[,count].",NULL) },
299 	{ DDB_ADD_CMD("break",	db_breakpoint_cmd,	0,
300 	    "Set a breakpoint at address", "[/u] address[,count].",NULL) },
301 	{ DDB_ADD_CMD("bt",		db_stack_trace_cmd,	0,
302 	    "Show backtrace.", "See help trace.",NULL) },
303 	{ DDB_ADD_CMD("c",		db_continue_cmd,	0,
304 	    "Continue execution.", "[/c]",NULL) },
305 	{ DDB_ADD_CMD("call",	db_fncall,		CS_OWN,
306 	    "Call the function", "address[(expression[,...])]",NULL) },
307 #ifdef _KERNEL	/* XXX CRASH(8) */
308 	{ DDB_ADD_CMD("callout",	db_show_callout,	0, NULL,
309 	    NULL,NULL ) },
310 #endif
311 	{ DDB_ADD_CMD("continue",	db_continue_cmd,	0,
312 	    "Continue execution.", "[/c]",NULL) },
313 	{ DDB_ADD_CMD("d",		db_delete_cmd,		0,
314 	    "Delete a breakpoint.", "address | #number",NULL) },
315 	{ DDB_ADD_CMD("delete",	db_delete_cmd,		0,
316 	    "Delete a breakpoint.", "address | #number",NULL) },
317 	{ DDB_ADD_CMD("dmesg",	db_dmesg,		0,
318 	    "Show kernel message buffer.", "[count]",NULL) },
319 	{ DDB_ADD_CMD("dwatch",	db_deletewatch_cmd,	0,
320 	    "Delete the watchpoint.", "address",NULL) },
321 	{ DDB_ADD_CMD("examine",	db_examine_cmd,		CS_SET_DOT,
322 	    "Display the address locations.",
323 	    "[/modifier] address[,count]",NULL) },
324 	{ DDB_ADD_CMD("exit",		db_continue_cmd,	0,
325 	    "Continue execution.", "[/c]",NULL) },
326 	{ DDB_ADD_CMD("help",   db_help_print_cmd, CS_OWN|CS_NOREPEAT,
327 	    "Display help about commands",
328 	    "Use other commands as arguments.",NULL) },
329 	{ DDB_ADD_CMD("kill",	db_kill_proc,		CS_OWN,
330 	    "Send a signal to the process","pid[,signal_number]",
331 	    "   pid:\t\t\tthe process id (may need 0t prefix for decimal)\n"
332 	    "   signal_number:\tthe signal to send") },
333 #ifdef KGDB
334 	{ DDB_ADD_CMD("kgdb",	db_kgdb_cmd,	0,	NULL,NULL,NULL) },
335 #endif
336 	{ DDB_ADD_CMD("machine",NULL,CS_MACH,
337 	    "Architecture specific functions.",NULL,NULL) },
338 	{ DDB_ADD_CMD("match",	db_trace_until_matching_cmd,0,
339 	    "Stop at the matching return instruction.","See help next",NULL) },
340 	{ DDB_ADD_CMD("next",	db_trace_until_matching_cmd,0,
341 	    "Stop at the matching return instruction.","[/p]",NULL) },
342 	{ DDB_ADD_CMD("p",		db_print_cmd,		0,
343 	    "Print address according to the format.",
344 	    "[/axzodurc] address [address ...]",NULL) },
345 	{ DDB_ADD_CMD("print",	db_print_cmd,		0,
346 	    "Print address according to the format.",
347 	    "[/axzodurc] address [address ...]",NULL) },
348 	{ DDB_ADD_CMD("ps",		db_show_all_procs,	0,
349 	    "Print all processes.","See show all procs",NULL) },
350 	{ DDB_ADD_CMD("quit",		db_continue_cmd,	0,
351 	    "Continue execution.", "[/c]",NULL) },
352 	{ DDB_ADD_CMD("reboot",	db_reboot_cmd,		CS_OWN,
353 	    "Reboot","0x1  RB_ASKNAME, 0x2 RB_SINGLE, 0x4 RB_NOSYNC, 0x8 RB_HALT,"
354 	    "0x40 RB_KDB, 0x100 RB_DUMP, 0x808 RB_POWERDOWN",NULL) },
355 	{ DDB_ADD_CMD("s",		db_single_step_cmd,	0,
356 	    "Single-step count times.","[/p] [,count]",NULL) },
357 	{ DDB_ADD_CMD("search",	db_search_cmd,		CS_OWN|CS_SET_DOT,
358 	    "Search memory from address for value.",
359 	    "[/bhl] address value [mask] [,count]",NULL) },
360 	{ DDB_ADD_CMD("set",	db_set_cmd,		CS_OWN,
361 	    "Set the named variable","$variable [=] expression",NULL) },
362 	{ DDB_ADD_CMD("show",	NULL, CS_SHOW,
363 	    "Show kernel stats.", NULL,NULL) },
364 	{ DDB_ADD_CMD("sifting",	db_sifting_cmd,		CS_OWN,
365 	    "Search the symbol tables ","[/F] string",NULL) },
366 	{ DDB_ADD_CMD("step",	db_single_step_cmd,	0,
367 	    "Single-step count times.","[/p] [,count]",NULL) },
368 	{ DDB_ADD_CMD("sync",	db_sync_cmd,		CS_OWN,
369 	    "Force a crash dump, and then reboot.",NULL,NULL) },
370 	{ DDB_ADD_CMD("trace",	db_stack_trace_cmd,	0,
371 	    "Stack trace from frame-address.",
372 	    "[/u[l]] [frame-address][,count]",NULL) },
373 	{ DDB_ADD_CMD("until",	db_trace_until_call_cmd,0,
374 	    "Stop at the next call or return instruction.","[/p]",NULL) },
375 	{ DDB_ADD_CMD("w",		db_write_cmd,		CS_MORE|CS_SET_DOT,
376 	    "Write the expressions at succeeding locations.",
377 	    "[/bhl] address expression [expression ...]",NULL) },
378 	{ DDB_ADD_CMD("watch",	db_watchpoint_cmd,	CS_MORE,
379 	    "Set a watchpoint for a region. ","address[,size]",NULL) },
380 	{ DDB_ADD_CMD("whatis",	db_whatis_cmd, 0,
381 	    "Describe what an address is", "address", NULL) },
382 	{ DDB_ADD_CMD("write",	db_write_cmd,		CS_MORE|CS_SET_DOT,
383 	    "Write the expressions at succeeding locations.",
384 	    "[/bhl] address expression [expression ...]",NULL) },
385 	{ DDB_ADD_CMD("x",		db_examine_cmd,		CS_SET_DOT,
386 	    "Display the address locations.",
387 	    "[/modifier] address[,count]",NULL) },
388 	{ DDB_ADD_CMD(NULL, 	NULL,		   0, NULL, NULL, NULL) }
389 };
390 
391 static const struct db_command	*db_last_command = NULL;
392 #if defined(DDB_COMMANDONENTER)
393 char db_cmd_on_enter[DB_LINE_MAXLEN + 1] = ___STRING(DDB_COMMANDONENTER);
394 #else /* defined(DDB_COMMANDONENTER) */
395 char db_cmd_on_enter[DB_LINE_MAXLEN + 1] = "";
396 #endif /* defined(DDB_COMMANDONENTER) */
397 #define	DB_LINE_SEP	';'
398 
399 /*
400  * Execute commandlist after ddb start
401  * This function goes through the command list created from commands and ';'
402  */
403 static void
404 db_execute_commandlist(const char *cmdlist)
405 {
406 	const char *cmd = cmdlist;
407 	const struct db_command	*dummy = NULL;
408 
409 	while (*cmd != '\0') {
410 		const char *ep = cmd;
411 
412 		while (*ep != '\0' && *ep != DB_LINE_SEP) {
413 			ep++;
414 		}
415 		db_set_line(cmd, ep);
416 		db_command(&dummy);
417 		cmd = ep;
418 		if (*cmd == DB_LINE_SEP) {
419 			cmd++;
420 		}
421 	}
422 }
423 
424 /* Initialize ddb command tables */
425 void
426 db_init_commands(void)
427 {
428 	static bool done = false;
429 
430 	if (done) return;
431 	done = true;
432 
433 	/* register command tables */
434 	(void)db_register_tbl_entry(DDB_BASE_CMD, &db_base_cmd_builtins);
435 #ifdef DB_MACHINE_COMMANDS
436 	(void)db_register_tbl_entry(DDB_MACH_CMD, &db_mach_cmd_builtins);
437 #endif
438 	(void)db_register_tbl_entry(DDB_SHOW_CMD, &db_show_cmd_builtins);
439 }
440 
441 
442 /*
443  * Add command table to the specified list
444  * Arg:
445  * int type specifies type of command table DDB_SHOW_CMD|DDB_BASE_CMD|DDB_MAC_CMD
446  * *cmd_tbl poiter to static allocated db_command table
447  *
448  * Command table must be NULL terminated array of struct db_command
449  */
450 int
451 db_register_tbl(uint8_t type, const struct db_command *cmd_tbl)
452 {
453 	struct db_cmd_tbl_en *list_ent;
454 
455 	/* empty list - ignore */
456 	if (cmd_tbl->name == 0)
457 		return 0;
458 
459 	/* force builtin commands to be registered first */
460 	db_init_commands();
461 
462 	/* now create a list entry for this table */
463 	list_ent = db_zalloc(sizeof(*list_ent));
464 	if (list_ent == NULL)
465 		return ENOMEM;
466 	list_ent->db_cmd=cmd_tbl;
467 
468 	/* and register it */
469 	return db_register_tbl_entry(type, list_ent);
470 }
471 
472 static int
473 db_register_tbl_entry(uint8_t type, struct db_cmd_tbl_en *list_ent)
474 {
475 	struct db_cmd_tbl_en_head *list;
476 
477 	switch(type) {
478 	case DDB_BASE_CMD:
479 		list = &db_base_cmd_list;
480 		break;
481 	case DDB_SHOW_CMD:
482 		list = &db_show_cmd_list;
483 		break;
484 	case DDB_MACH_CMD:
485 		list = &db_mach_cmd_list;
486 		break;
487 	default:
488 		return ENOENT;
489 	}
490 
491 	TAILQ_INSERT_TAIL(list, list_ent, db_cmd_next);
492 
493 	return 0;
494 }
495 
496 /*
497  * Remove command table specified with db_cmd address == cmd_tbl
498  */
499 int
500 db_unregister_tbl(uint8_t type,const struct db_command *cmd_tbl)
501 {
502 	struct db_cmd_tbl_en *list_ent;
503 	struct db_cmd_tbl_en_head *list;
504 
505 	/* find list on which the entry should live */
506 	switch (type) {
507 	case DDB_BASE_CMD:
508 		list=&db_base_cmd_list;
509 		break;
510 	case DDB_SHOW_CMD:
511 		list=&db_show_cmd_list;
512 		break;
513 	case DDB_MACH_CMD:
514 		list=&db_mach_cmd_list;
515 		break;
516 	default:
517 		return EINVAL;
518 	}
519 
520 	TAILQ_FOREACH (list_ent, list, db_cmd_next) {
521 		if (list_ent->db_cmd == cmd_tbl){
522 			TAILQ_REMOVE(list,
523 			    list_ent, db_cmd_next);
524 			db_free(list_ent, sizeof(*list_ent));
525 			return 0;
526 		}
527 	}
528 	return ENOENT;
529 }
530 
531 /* This function is called from machine trap code. */
532 void
533 db_command_loop(void)
534 {
535 	label_t	db_jmpbuf;
536 	label_t	*savejmp;
537 
538 	/*
539 	 * Initialize 'prev' and 'next' to dot.
540 	 */
541 	db_prev = db_dot;
542 	db_next = db_dot;
543 
544 	db_cmd_loop_done = false;
545 
546 	/* Init default command tables add machine, base,
547 	   show command tables to the list */
548 	db_init_commands();
549 
550 	/* save context for return from ddb */
551 	savejmp = db_recover;
552 	db_recover = &db_jmpbuf;
553 	(void) setjmp(&db_jmpbuf);
554 
555 	/* Execute default ddb start commands */
556 	db_execute_commandlist(db_cmd_on_enter);
557 
558 	(void) setjmp(&db_jmpbuf);
559 	while (!db_cmd_loop_done) {
560 		if (db_print_position() != 0)
561 			db_printf("\n");
562 		db_output_line = 0;
563 		(void) db_read_line();
564 		db_command(&db_last_command);
565 	}
566 
567 	db_recover = savejmp;
568 }
569 
570 /*
571  * Search command table for command prefix
572  */
573 static int
574 db_cmd_search_table(const char *name,
575 		    const struct db_command *table,
576 		    const struct db_command **cmdp)
577 {
578 
579 	const struct db_command	*cmd;
580 	int result;
581 
582 	result = CMD_NONE;
583 	*cmdp = NULL;
584 
585 	for (cmd = table; cmd->name != 0; cmd++) {
586 		const char *lp;
587 		const char *rp;
588 
589 		lp = name;
590 		rp = cmd->name;
591 		while (*lp != '\0' && *lp == *rp) {
592 			rp++;
593 			lp++;
594 		}
595 
596 		if (*lp != '\0') /* mismatch or extra chars in name */
597 			continue;
598 
599 		if (*rp == '\0') { /* exact match */
600 			*cmdp = cmd;
601 			return (CMD_EXACT);
602 		}
603 
604 		/* prefix match: end of name, not end of command */
605 		if (result == CMD_NONE) {
606 			result = CMD_PREFIX;
607 			*cmdp = cmd;
608 		}
609 		else if (result == CMD_PREFIX) {
610 			result = CMD_AMBIGUOUS;
611 			*cmdp = NULL;
612 		}
613 	}
614 
615 	return (result);
616 }
617 
618 
619 /*
620  * Search list of command tables for command
621  */
622 static int
623 db_cmd_search(const char *name,
624 	      struct db_cmd_tbl_en_head *list_head,
625 	      const struct db_command **cmdp)
626 {
627 	struct db_cmd_tbl_en *list_ent;
628 	const struct db_command *found_command;
629 	bool accept_prefix_match;
630 	int result;
631 
632 	result = CMD_NONE;
633 	found_command = NULL;
634 	accept_prefix_match = true;
635 
636 	TAILQ_FOREACH(list_ent, list_head, db_cmd_next) {
637 		const struct db_command *cmd;
638 		int found;
639 
640 		found = db_cmd_search_table(name, list_ent->db_cmd, &cmd);
641 		if (found == CMD_EXACT) {
642 			result = CMD_EXACT;
643 			found_command = cmd;
644 			break;
645 		}
646 
647 		if (found == CMD_PREFIX) {
648 			if (accept_prefix_match) {
649 				/*
650 				 * Continue search, but note current result
651 				 * in case we won't find anything else.
652 				 */
653 				accept_prefix_match = false;
654 				result = CMD_PREFIX;
655 				found_command = cmd;
656 			} else {
657 				/*
658 				 * Watch out for globally ambiguous
659 				 * prefix match that is not locally
660 				 * ambiguous - with one match in one
661 				 * table and another match(es) in
662 				 * another table.
663 				 */
664 				result = CMD_AMBIGUOUS;
665 				found_command = NULL;
666 			}
667 		}
668 		else if (found == CMD_AMBIGUOUS) {
669 			accept_prefix_match = false;
670 			result = CMD_AMBIGUOUS;
671 			found_command = NULL;
672 		}
673 	}
674 
675 	*cmdp = found_command;
676 	return result;
677 }
678 
679 static void
680 db_cmd_search_failed(char *name, int search_result)
681 {
682 	if (search_result == CMD_NONE)
683 		db_printf("No such command: %s\n", name);
684 	else
685 		db_printf("Ambiguous command: %s\n", name);
686 }
687 
688 
689 /*
690  * List commands to the console.
691  */
692 static void
693 db_cmd_list(const struct db_cmd_tbl_en_head *list)
694 {
695 
696 	struct db_cmd_tbl_en *list_ent;
697 	const struct db_command *table;
698 	size_t		i, j, w, columns, lines, numcmds, width=0;
699 	const char	*p;
700 
701 	TAILQ_FOREACH(list_ent,list,db_cmd_next) {
702 		table = list_ent->db_cmd;
703 		for (i = 0; table[i].name != NULL; i++) {
704 			w = strlen(table[i].name);
705 			if (w > width)
706 				width = w;
707 		}
708 	}
709 
710 	width = DB_NEXT_TAB(width);
711 
712 	columns = db_max_width / width;
713 	if (columns == 0)
714 		columns = 1;
715 
716 	TAILQ_FOREACH(list_ent,list,db_cmd_next) {
717 		table = list_ent->db_cmd;
718 
719 		for (numcmds = 0; table[numcmds].name != NULL; numcmds++)
720 			;
721 		lines = (numcmds + columns - 1) / columns;
722 
723 		for (i = 0; i < lines; i++) {
724 			for (j = 0; j < columns; j++) {
725 				p = table[j * lines + i].name;
726 				if (p)
727 					db_printf("%s", p);
728 				if (j * lines + i + lines >= numcmds) {
729 					db_putchar('\n');
730 					break;
731 				}
732 				if (p) {
733 					w = strlen(p);
734 					while (w < width) {
735 						w = DB_NEXT_TAB(w);
736 						db_putchar('\t');
737 					}
738 				}
739 			}
740 		}
741 	}
742 	return;
743 }
744 
745 /*
746  * Read complete command with all subcommands, starting with current
747  * db_tok_string. If subcommand is missing, print the list of all
748  * subcommands.  If command/subcommand is not found, print an error
749  * message.  Returns pointer to "leaf" command or NULL.
750  */
751 static const struct db_command *
752 db_read_command(void)
753 {
754 	const struct db_command *command;
755 	struct db_cmd_tbl_en_head *list;
756 	int found;
757 	int t;
758 
759 	list = &db_base_cmd_list;
760 	do {
761 		found = db_cmd_search(db_tok_string, list, &command);
762 		if (command == NULL) {
763 			db_cmd_search_failed(db_tok_string, found);
764 			db_flush_lex();
765 			return NULL;
766 		}
767 
768 		if (command->flag == CS_SHOW)
769 			list = &db_show_cmd_list;
770 		else if (command->flag == CS_MACH)
771 			list = &db_mach_cmd_list;
772 		else if (command->flag == CS_COMPAT)
773 			/* same list */;
774 		else
775 			break; /* expect no more subcommands */
776 
777 		t = db_read_token(); /* read subcommand */
778 		if (t != tIDENT) {
779 			/* if none given - just print all of them */
780 			db_cmd_list(list);
781 			db_flush_lex();
782 			return NULL;
783 		}
784 	} while (list != NULL);
785 
786 	return command;
787 }
788 
789 /*
790  * Parse command line and execute apropriate function.
791  */
792 static void
793 db_command(const struct db_command **last_cmdp)
794 {
795 	const struct db_command *command;
796 	static db_expr_t last_count = 0;
797 	db_expr_t	addr, count;
798 	char		modif[TOK_STRING_SIZE];
799 
800 	int			t;
801 	bool		have_addr = false;
802 
803 	command = NULL;
804 
805 	t = db_read_token();
806 	if ((t == tEOL) || (t == tCOMMA)) {
807 		/*
808 		 * An empty line repeats last command, at 'next'.
809 		 * Only a count repeats the last command with the new count.
810 		 */
811 		command = *last_cmdp;
812 
813 		if (!command)
814 			return;
815 
816 		addr = (db_expr_t)db_next;
817 		if (t == tCOMMA) {
818 			if (!db_expression(&count)) {
819 				db_printf("Count missing\n");
820 				db_flush_lex();
821 				return;
822 			}
823 		} else
824 			count = last_count;
825 		have_addr = false;
826 		modif[0] = '\0';
827 		db_skip_to_eol();
828 
829 	} else if (t == tEXCL) {
830 		db_fncall(0, 0, 0, NULL);
831 		return;
832 
833 	} else if (t != tIDENT) {
834 		db_printf("?\n");
835 		db_flush_lex();
836 		return;
837 
838 	} else {
839 
840 		command = db_read_command();
841 		if (command == NULL)
842 			return;
843 
844 		if ((command->flag & CS_OWN) == 0) {
845 
846 			/*
847 			 * Standard syntax:
848 			 * command [/modifier] [addr] [,count]
849 			 */
850 			t = db_read_token(); /* get modifier */
851 			if (t == tSLASH) {
852 				t = db_read_token();
853 				if (t != tIDENT) {
854 					db_printf("Bad modifier\n");
855 					db_flush_lex();
856 					return;
857 				}
858 				/* save modifier */
859 				strlcpy(modif, db_tok_string, sizeof(modif));
860 
861 			} else {
862 				db_unread_token(t);
863 				modif[0] = '\0';
864 			}
865 
866 			if (db_expression(&addr)) { /*get address*/
867 				db_dot = (db_addr_t) addr;
868 				db_last_addr = db_dot;
869 				have_addr = true;
870 			} else {
871 				addr = (db_expr_t) db_dot;
872 				have_addr = false;
873 			}
874 
875 			t = db_read_token();
876 			if (t == tCOMMA) { /*Get count*/
877 				if (!db_expression(&count)) {
878 					db_printf("Count missing\n");
879 					db_flush_lex();
880 					return;
881 				}
882 			} else {
883 				db_unread_token(t);
884 				count = -1;
885 			}
886 			if ((command->flag & CS_MORE) == 0) {
887 				db_skip_to_eol();
888 			}
889 		}
890 	}
891 
892 	if (command != NULL && command->flag & CS_NOREPEAT) {
893 		*last_cmdp = NULL;
894 		last_count = 0;
895 	} else {
896 		*last_cmdp = command;
897 		last_count = count;
898 	}
899 
900 
901 	if (command != NULL) {
902 		/*
903 		 * Execute the command.
904 		 */
905 		if (command->fcn != NULL)
906 			(*command->fcn)(addr, have_addr, count, modif);
907 
908 		if (command->flag & CS_SET_DOT) {
909 			/*
910 			 * If command changes dot, set dot to
911 			 * previous address displayed (if 'ed' style).
912 			 */
913 			if (db_ed_style)
914 				db_dot = db_prev;
915 			else
916 				db_dot = db_next;
917 		} else {
918 			/*
919 			 * If command does not change dot,
920 			 * set 'next' location to be the same.
921 			 */
922 			db_next = db_dot;
923 		}
924 	}
925 }
926 
927 /*
928  * Print help for commands
929  */
930 static void
931 db_help_print_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
932 const char *modif)
933 {
934 	const struct db_command *command;
935 	int t;
936 
937 	t = db_read_token();
938 
939 	/* is there another command after the "help"? */
940 	if (t != tIDENT) {
941 		/* print base commands */
942 		db_cmd_list(&db_base_cmd_list);
943 		return;
944 	}
945 
946 	command = db_read_command();
947 	if (command == NULL)
948 		return;
949 
950 #ifdef DDB_VERBOSE_HELP
951 	db_printf("Command: %s\n", command->name);
952 	if (command->cmd_descr != NULL)
953 		db_printf(" Description: %s\n", command->cmd_descr);
954 	if (command->cmd_arg != NULL)
955 		db_printf(" Arguments: %s\n", command->cmd_arg);
956 	if (command->cmd_arg_help != NULL)
957 		db_printf(" Arguments description:\n%s\n",
958 			  command->cmd_arg_help);
959 	if ((command->cmd_arg == NULL) && (command->cmd_descr == NULL))
960 		db_printf(" No help message.\n");
961 #endif
962 
963 	db_skip_to_eol();
964 }
965 
966 /*ARGSUSED*/
967 static void
968 db_map_print_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
969     const char *modif)
970 {
971 	bool full = false;
972 
973 	if (modif[0] == 'f')
974 		full = true;
975 
976 	if (have_addr == false)
977 		addr = (db_expr_t)(uintptr_t)db_read_ptr("kernel_map");
978 
979 #ifdef _KERNEL
980 	uvm_map_printit((struct vm_map *)(uintptr_t) addr, full, db_printf);
981 #endif	/* XXX CRASH(8) */
982 }
983 
984 /*ARGSUSED*/
985 static void
986 db_malloc_print_cmd(db_expr_t addr, bool have_addr,
987     db_expr_t count, const char *modif)
988 {
989 
990 #ifdef MALLOC_DEBUG
991 	if (!have_addr)
992 		addr = 0;
993 
994 	debug_malloc_printit(db_printf, (vaddr_t) addr);
995 #else
996 	db_printf("The kernel is not built with the MALLOC_DEBUG option.\n");
997 #endif /* MALLOC_DEBUG */
998 }
999 
1000 /*ARGSUSED*/
1001 static void
1002 db_object_print_cmd(db_expr_t addr, bool have_addr,
1003     db_expr_t count, const char *modif)
1004 {
1005 	bool full = false;
1006 
1007 	if (modif[0] == 'f')
1008 		full = true;
1009 
1010 #ifdef _KERNEL /* XXX CRASH(8) */
1011 	uvm_object_printit((struct uvm_object *)(uintptr_t) addr, full,
1012 	    db_printf);
1013 #endif
1014 }
1015 
1016 /*ARGSUSED*/
1017 static void
1018 db_page_print_cmd(db_expr_t addr, bool have_addr,
1019     db_expr_t count, const char *modif)
1020 {
1021 	bool full = false;
1022 
1023 	if (modif[0] == 'f')
1024 		full = true;
1025 
1026 #ifdef _KERNEL /* XXX CRASH(8) */
1027 	uvm_page_printit((struct vm_page *)(uintptr_t) addr, full, db_printf);
1028 #endif
1029 }
1030 
1031 /*ARGSUSED*/
1032 static void
1033 db_show_all_pages(db_expr_t addr, bool have_addr,
1034     db_expr_t count, const char *modif)
1035 {
1036 
1037 #ifdef _KERNEL /* XXX CRASH(8) */
1038 	uvm_page_printall(db_printf);
1039 #endif
1040 }
1041 
1042 /*ARGSUSED*/
1043 static void
1044 db_buf_print_cmd(db_expr_t addr, bool have_addr,
1045     db_expr_t count, const char *modif)
1046 {
1047 	bool full = false;
1048 
1049 	if (modif[0] == 'f')
1050 		full = true;
1051 
1052 #ifdef _KERNEL /* XXX CRASH(8) */
1053 	vfs_buf_print((struct buf *)(uintptr_t) addr, full, db_printf);
1054 #endif
1055 }
1056 
1057 /*ARGSUSED*/
1058 static void
1059 db_event_print_cmd(db_expr_t addr, bool have_addr,
1060     db_expr_t count, const char *modif)
1061 {
1062 	bool full = false;
1063 	struct evcnt ev, *evp;
1064 	char buf[80];
1065 
1066 	if (modif[0] == 'f')
1067 		full = true;
1068 
1069 	evp = (struct evcnt *)db_read_ptr("allevents");
1070 	while (evp != NULL) {
1071 		db_read_bytes((db_addr_t)evp, sizeof(ev), (char *)&ev);
1072 		evp = ev.ev_list.tqe_next;
1073 		if (ev.ev_count == 0 && !full)
1074 			continue;
1075 		db_read_bytes((db_addr_t)ev.ev_group, ev.ev_grouplen + 1, buf);
1076 		db_printf("evcnt type %d: %s ", ev.ev_type, buf);
1077 		db_read_bytes((db_addr_t)ev.ev_name, ev.ev_namelen + 1, buf);
1078 		db_printf("%s = %lld\n", buf, (long long)ev.ev_count);
1079 	}
1080 }
1081 
1082 /*ARGSUSED*/
1083 static void
1084 db_vnode_print_cmd(db_expr_t addr, bool have_addr,
1085     db_expr_t count, const char *modif)
1086 {
1087 	bool full = false;
1088 
1089 	if (modif[0] == 'f')
1090 		full = true;
1091 
1092 #ifdef _KERNEL /* XXX CRASH(8) */
1093 	vfs_vnode_print((struct vnode *)(uintptr_t) addr, full, db_printf);
1094 #endif
1095 }
1096 
1097 /*ARGSUSED*/
1098 static void
1099 db_vmem_print_cmd(db_expr_t addr, bool have_addr,
1100     db_expr_t count, const char *modif)
1101 {
1102 
1103 #ifdef _KERNEL /* XXX CRASH(8) */
1104 	vmem_print((uintptr_t) addr, modif, db_printf);
1105 #endif
1106 }
1107 
1108 static void
1109 db_mount_print_cmd(db_expr_t addr, bool have_addr,
1110     db_expr_t count, const char *modif)
1111 {
1112 	bool full = false;
1113 
1114 	if (modif[0] == 'f')
1115 		full = true;
1116 
1117 #ifdef _KERNEL	/* XXX CRASH(8) */
1118 	vfs_mount_print((struct mount *)(uintptr_t) addr, full, db_printf);
1119 #endif
1120 }
1121 
1122 /*ARGSUSED*/
1123 static void
1124 db_mbuf_print_cmd(db_expr_t addr, bool have_addr,
1125     db_expr_t count, const char *modif)
1126 {
1127 
1128 #ifdef _KERNEL /* XXX CRASH(8) */
1129 	m_print((const struct mbuf *)(uintptr_t) addr, modif, db_printf);
1130 #endif
1131 }
1132 
1133 /*ARGSUSED*/
1134 static void
1135 db_pool_print_cmd(db_expr_t addr, bool have_addr,
1136     db_expr_t count, const char *modif)
1137 {
1138 
1139 #ifdef _KERNEL /* XXX CRASH(8) */
1140 	pool_printit((struct pool *)(uintptr_t) addr, modif, db_printf);
1141 #endif
1142 }
1143 
1144 /*ARGSUSED*/
1145 static void
1146 db_namecache_print_cmd(db_expr_t addr, bool have_addr,
1147     db_expr_t count, const char *modif)
1148 {
1149 
1150 #ifdef _KERNEL /* XXX CRASH(8) */
1151 	namecache_print((struct vnode *)(uintptr_t) addr, db_printf);
1152 #endif
1153 }
1154 
1155 /*ARGSUSED*/
1156 static void
1157 db_uvmexp_print_cmd(db_expr_t addr, bool have_addr,
1158     db_expr_t count, const char *modif)
1159 {
1160 
1161 #ifdef _KERNEL	/* XXX CRASH(8) */
1162 	uvmexp_print(db_printf);
1163 #endif
1164 }
1165 
1166 #ifdef UVMHIST
1167 /*ARGSUSED*/
1168 static void
1169 db_uvmhist_print_cmd(db_expr_t addr, bool have_addr,
1170     db_expr_t count, const char *modif)
1171 {
1172 
1173 	uvmhist_print(db_printf);
1174 }
1175 #endif
1176 
1177 /*ARGSUSED*/
1178 static void
1179 db_lock_print_cmd(db_expr_t addr, bool have_addr,
1180     db_expr_t count, const char *modif)
1181 {
1182 
1183 #ifdef _KERNEL	/* XXX CRASH(8) */
1184 	lockdebug_lock_print((void *)(uintptr_t)addr, db_printf);
1185 #endif
1186 }
1187 
1188 /*
1189  * Call random function:
1190  * !expr(arg,arg,arg)
1191  */
1192 /*ARGSUSED*/
1193 static void
1194 db_fncall(db_expr_t addr, bool have_addr,
1195     db_expr_t count, const char *modif)
1196 {
1197 #ifdef _KERNEL
1198 	db_expr_t	fn_addr;
1199 #define	MAXARGS		11
1200 	db_expr_t	args[MAXARGS];
1201 	int		nargs = 0;
1202 	db_expr_t	retval;
1203 	db_expr_t	(*func)(db_expr_t, ...);
1204 	int		t;
1205 
1206 	if (!db_expression(&fn_addr)) {
1207 		db_printf("Bad function\n");
1208 		db_flush_lex();
1209 		return;
1210 	}
1211 	func = (db_expr_t (*)(db_expr_t, ...))(uintptr_t) fn_addr;
1212 
1213 	t = db_read_token();
1214 	if (t == tLPAREN) {
1215 		if (db_expression(&args[0])) {
1216 			nargs++;
1217 			while ((t = db_read_token()) == tCOMMA) {
1218 				if (nargs == MAXARGS) {
1219 					db_printf("Too many arguments\n");
1220 					db_flush_lex();
1221 					return;
1222 				}
1223 				if (!db_expression(&args[nargs])) {
1224 					db_printf("Argument missing\n");
1225 					db_flush_lex();
1226 					return;
1227 				}
1228 				nargs++;
1229 			}
1230 			db_unread_token(t);
1231 		}
1232 		if (db_read_token() != tRPAREN) {
1233 			db_printf("?\n");
1234 			db_flush_lex();
1235 			return;
1236 		}
1237 	}
1238 	db_skip_to_eol();
1239 
1240 	while (nargs < MAXARGS) {
1241 		args[nargs++] = 0;
1242 	}
1243 
1244 	retval = (*func)(args[0], args[1], args[2], args[3], args[4],
1245 			 args[5], args[6], args[7], args[8], args[9]);
1246 	db_printf("%s\n", db_num_to_str(retval));
1247 #else	/* _KERNEL */
1248 	db_printf("This command can only be used in-kernel.\n");
1249 #endif	/* _KERNEL */
1250 }
1251 
1252 static void
1253 db_reboot_cmd(db_expr_t addr, bool have_addr,
1254     db_expr_t count, const char *modif)
1255 {
1256 #ifdef _KERNEL
1257 	db_expr_t bootflags;
1258 
1259 	/* Flags, default to RB_AUTOBOOT */
1260 	if (!db_expression(&bootflags))
1261 		bootflags = (db_expr_t)RB_AUTOBOOT;
1262 	if (db_read_token() != tEOL) {
1263 		db_error("?\n");
1264 		/*NOTREACHED*/
1265 	}
1266 	/*
1267 	 * We are leaving DDB, never to return upward.
1268 	 * Clear db_recover so that we can debug faults in functions
1269 	 * called from cpu_reboot.
1270 	 */
1271 	db_recover = 0;
1272 	cpu_reboot((int)bootflags, NULL);
1273 #else	/* _KERNEL */
1274 	db_printf("This command can only be used in-kernel.\n");
1275 #endif	/* _KERNEL */
1276 }
1277 
1278 static void
1279 db_sifting_cmd(db_expr_t addr, bool have_addr,
1280     db_expr_t count, const char *modif)
1281 {
1282 	int	mode, t;
1283 
1284 	t = db_read_token();
1285 	if (t == tSLASH) {
1286 		t = db_read_token();
1287 		if (t != tIDENT) {
1288 			bad_modifier:
1289 			db_printf("Bad modifier\n");
1290 			db_flush_lex();
1291 			return;
1292 		}
1293 		if (!strcmp(db_tok_string, "F"))
1294 			mode = 'F';
1295 		else
1296 			goto bad_modifier;
1297 		t = db_read_token();
1298 	} else
1299 		mode = 0;
1300 
1301 	if (t == tIDENT)
1302 		db_sifting(db_tok_string, mode);
1303 	else {
1304 		db_printf("Bad argument (non-string)\n");
1305 		db_flush_lex();
1306 	}
1307 }
1308 
1309 static void
1310 db_stack_trace_cmd(db_expr_t addr, bool have_addr, db_expr_t count, const char *modif)
1311 {
1312 	register const char *cp = modif;
1313 	register char c;
1314 	void (*pr)(const char *, ...);
1315 
1316 	pr = db_printf;
1317 	while ((c = *cp++) != 0)
1318 		if (c == 'l')
1319 			pr = (void (*)(const char *, ...))printf;
1320 
1321 	if (count == -1)
1322 		count = 65535;
1323 
1324 	db_stack_trace_print(addr, have_addr, count, modif, pr);
1325 }
1326 
1327 static void
1328 db_sync_cmd(db_expr_t addr, bool have_addr,
1329     db_expr_t count, const char *modif)
1330 {
1331 #ifdef _KERNEL
1332 	/*
1333 	 * We are leaving DDB, never to return upward.
1334 	 * Clear db_recover so that we can debug faults in functions
1335 	 * called from cpu_reboot.
1336 	 */
1337 	db_recover = 0;
1338 	panicstr = "dump forced via kernel debugger";
1339 	cpu_reboot(RB_DUMP, NULL);
1340 #else	/* _KERNEL */
1341 	db_printf("This command can only be used in-kernel.\n");
1342 #endif	/* _KERNEL */
1343 }
1344 
1345 /*
1346  * Describe what an address is
1347  */
1348 void
1349 db_whatis_cmd(db_expr_t address, bool have_addr,
1350     db_expr_t count, const char *modif)
1351 {
1352 	const uintptr_t addr = (uintptr_t)address;
1353 
1354 	db_lwp_whatis(addr, db_printf);
1355 #ifdef _KERNEL	/* XXX CRASH(8) */
1356 	pool_whatis(addr, db_printf);
1357 	vmem_whatis(addr, db_printf);
1358 	uvm_whatis(addr, db_printf);
1359 	module_whatis(addr, db_printf);
1360 #endif
1361 }
1362