xref: /netbsd-src/sys/ddb/db_command.c (revision 8b0f9554ff8762542c4defc4f70e1eb76fb508fa)
1 /*	$NetBSD: db_command.c,v 1.112 2007/12/13 02:45:11 yamt Exp $	*/
2 /*
3  * Mach Operating System
4  * Copyright (c) 1991,1990 Carnegie Mellon University
5  * All Rights Reserved.
6  *
7  * Permission to use, copy, modify and distribute this software and its
8  * documentation is hereby granted, provided that both the copyright
9  * notice and this permission notice appear in all copies of the
10  * software, derivative works or modified versions, and any portions
11  * thereof, and that both notices appear in supporting documentation.
12  *
13  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
14  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
15  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
16  *
17  * Carnegie Mellon requests users of this software to return to
18  *
19  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
20  *  School of Computer Science
21  *  Carnegie Mellon University
22  *  Pittsburgh PA 15213-3890
23  *
24  * any improvements or extensions that they make and grant Carnegie the
25  * rights to redistribute these changes.
26  */
27 /*
28  * Copyright (c) 1996, 1997, 1998, 1999, 2002 The NetBSD Foundation, Inc.
29  * All rights reserved.
30  *
31  * This code is derived from software contributed to The NetBSD Foundation
32  * by Adam Hamsik.
33  *
34  * Redistribution and use in source and binary forms, with or without
35  * modification, are permitted provided that the following conditions
36  * are met:
37  * 1. Redistributions of source code must retain the above copyright
38  *    notice, this list of conditions and the following disclaimer.
39  * 2. Redistributions in binary form must reproduce the above copyright
40  *    notice, this list of conditions and the following disclaimer in the
41  *    documentation and/or other materials provided with the distribution.
42  * 3. All advertising materials mentioning features or use of this software
43  *    must display the following acknowledgement:
44  *        This product includes software developed by the NetBSD
45  *        Foundation, Inc. and its contributors.
46  * 4. Neither the name of The NetBSD Foundation nor the names of its
47  *    contributors may be used to endorse or promote products derived
48  *    from this software without specific prior written permission.
49  *
50  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
51  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
52  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
53  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
54  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
55  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
56  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
57  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
58  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
59  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
60  * POSSIBILITY OF SUCH DAMAGE.
61  */
62 
63 /*
64  * Command dispatcher.
65  */
66 
67 #include <sys/cdefs.h>
68 __KERNEL_RCSID(0, "$NetBSD: db_command.c,v 1.112 2007/12/13 02:45:11 yamt Exp $");
69 
70 #include "opt_ddb.h"
71 #include "opt_kgdb.h"
72 #include "opt_inet.h"
73 #include "opt_ddbparam.h"
74 
75 #include <sys/param.h>
76 #include <sys/systm.h>
77 #include <sys/reboot.h>
78 #include <sys/device.h>
79 #include <sys/lwp.h>
80 #include <sys/malloc.h>
81 #include <sys/mbuf.h>
82 #include <sys/namei.h>
83 #include <sys/pool.h>
84 #include <sys/proc.h>
85 #include <sys/vnode.h>
86 #include <sys/vmem.h>
87 #include <sys/lockdebug.h>
88 #include <sys/sleepq.h>
89 #include <sys/cpu.h>
90 
91 /*include queue macros*/
92 #include <sys/queue.h>
93 
94 #include <machine/db_machdep.h>		/* type definitions */
95 
96 #if defined(_KERNEL_OPT)
97 #include "opt_multiprocessor.h"
98 #endif
99 
100 #include <ddb/db_lex.h>
101 #include <ddb/db_output.h>
102 #include <ddb/db_command.h>
103 #include <ddb/db_break.h>
104 #include <ddb/db_watch.h>
105 #include <ddb/db_run.h>
106 #include <ddb/db_variables.h>
107 #include <ddb/db_interface.h>
108 #include <ddb/db_sym.h>
109 #include <ddb/db_extern.h>
110 
111 #include <uvm/uvm_extern.h>
112 #include <uvm/uvm_ddb.h>
113 
114 #include "arp.h"
115 
116 /*
117  * Results of command search.
118  */
119 #define	CMD_UNIQUE	0
120 #define	CMD_FOUND	1
121 #define	CMD_NONE	2
122 #define	CMD_AMBIGUOUS	3
123 
124 /*
125  * Exported global variables
126  */
127 bool		db_cmd_loop_done;
128 label_t		*db_recover;
129 db_addr_t	db_dot;
130 db_addr_t	db_last_addr;
131 db_addr_t	db_prev;
132 db_addr_t	db_next;
133 
134 
135 /*
136   New DDB api for adding and removing commands uses three lists, because
137   we use two types of commands
138   a) standard commands without subcommands -> reboot
139   b) show commands which are subcommands of show command -> show aio_jobs
140   c) if defined machine specific commands
141 
142   ddb_add_cmd, ddb_rem_cmd use type (DDB_SHOW_CMD||DDB_BASE_CMD)argument to
143   add them to representativ lists.
144 */
145 
146 static const struct db_command db_command_table[];
147 static const struct db_command db_show_cmds[];
148 #ifdef DB_MACHINE_COMMANDS
149 static const struct db_command db_machine_command_table[];
150 #endif
151 
152 /* the global queue of all command tables */
153 TAILQ_HEAD(db_cmd_tbl_en_head, db_cmd_tbl_en);
154 
155 /* TAILQ entry used to register command tables */
156 struct db_cmd_tbl_en {
157 	const struct db_command *db_cmd;	/* cmd table */
158 	TAILQ_ENTRY(db_cmd_tbl_en) db_cmd_next;
159 };
160 
161 /* head of base commands list */
162 static struct db_cmd_tbl_en_head db_base_cmd_list =
163 	TAILQ_HEAD_INITIALIZER(db_base_cmd_list);
164 static struct db_cmd_tbl_en db_base_cmd_builtins =
165      { .db_cmd = db_command_table };
166 
167 /* head of show commands list */
168 static struct db_cmd_tbl_en_head db_show_cmd_list =
169 	TAILQ_HEAD_INITIALIZER(db_show_cmd_list);
170 static struct db_cmd_tbl_en db_show_cmd_builtins =
171      { .db_cmd = db_show_cmds };
172 
173 /* head of machine commands list */
174 static struct db_cmd_tbl_en_head db_mach_cmd_list =
175 	TAILQ_HEAD_INITIALIZER(db_mach_cmd_list);
176 #ifdef DB_MACHINE_COMMANDS
177 static struct db_cmd_tbl_en db_mach_cmd_builtins =
178      { .db_cmd = db_machine_command_table };
179 #endif
180 
181 /*
182  * if 'ed' style: 'dot' is set at start of last item printed,
183  * and '+' points to next line.
184  * Otherwise: 'dot' points to next item, '..' points to last.
185  */
186 static bool	 db_ed_style = true;
187 
188 static void	db_init_commands(void);
189 static int	db_register_tbl_entry(uint8_t type,
190     struct db_cmd_tbl_en *list_ent);
191 static void	db_cmd_list(const struct db_cmd_tbl_en_head *);
192 static int	db_cmd_search(const char *, const struct db_command *,
193     const struct db_command **);
194 static void	db_command(const struct db_command **);
195 static void	db_buf_print_cmd(db_expr_t, bool, db_expr_t, const char *);
196 static void	db_event_print_cmd(db_expr_t, bool, db_expr_t, const char *);
197 static void	db_fncall(db_expr_t, bool, db_expr_t, const char *);
198 static int      db_get_list_type(const char *);
199 static void     db_help_print_cmd(db_expr_t, bool, db_expr_t, const char *);
200 static void	db_lock_print_cmd(db_expr_t, bool, db_expr_t, const char *);
201 static void	db_mount_print_cmd(db_expr_t, bool, db_expr_t, const char *);
202 static void	db_mbuf_print_cmd(db_expr_t, bool, db_expr_t, const char *);
203 static void	db_malloc_print_cmd(db_expr_t, bool, db_expr_t, const char *);
204 static void	db_map_print_cmd(db_expr_t, bool, db_expr_t, const char *);
205 static void	db_namecache_print_cmd(db_expr_t, bool, db_expr_t,
206 		    const char *);
207 static void	db_object_print_cmd(db_expr_t, bool, db_expr_t, const char *);
208 static void	db_page_print_cmd(db_expr_t, bool, db_expr_t, const char *);
209 static void	db_show_all_pages(db_expr_t, bool, db_expr_t, const char *);
210 static void	db_pool_print_cmd(db_expr_t, bool, db_expr_t, const char *);
211 static void	db_reboot_cmd(db_expr_t, bool, db_expr_t, const char *);
212 static void	db_sifting_cmd(db_expr_t, bool, db_expr_t, const char *);
213 static void	db_stack_trace_cmd(db_expr_t, bool, db_expr_t, const char *);
214 static void	db_sync_cmd(db_expr_t, bool, db_expr_t, const char *);
215 static void	db_whatis_cmd(db_expr_t, bool, db_expr_t, const char *);
216 static void	db_uvmexp_print_cmd(db_expr_t, bool, db_expr_t, const char *);
217 static void	db_vnode_print_cmd(db_expr_t, bool, db_expr_t, const char *);
218 
219 static const struct db_command db_show_cmds[] = {
220 	/*added from all sub cmds*/
221 	{ DDB_ADD_CMD("callout",  db_show_callout,
222 	    0 ,"List all used callout functions.",NULL,NULL) },
223 	{ DDB_ADD_CMD("pages",	db_show_all_pages,
224 	    0 ,"List all used memory pages.",NULL,NULL) },
225 	{ DDB_ADD_CMD("procs",	db_show_all_procs,
226 	    0 ,"List all processes.",NULL,NULL) },
227 	{ DDB_ADD_CMD("pools",	db_show_all_pools,
228 	    0 ,"Show all poolS",NULL,NULL) },
229 	/*added from all sub cmds*/
230 	{ DDB_ADD_CMD("aio_jobs",	db_show_aio_jobs,	0,
231 	    "Show aio jobs",NULL,NULL) },
232 	{ DDB_ADD_CMD("all",	NULL,
233 	    CS_COMPAT, NULL,NULL,NULL) },
234 #if defined(INET) && (NARP > 0)
235 	{ DDB_ADD_CMD("arptab",	db_show_arptab,		0,NULL,NULL,NULL) },
236 #endif
237 	{ DDB_ADD_CMD("breaks",	db_listbreak_cmd, 	0,
238 	    "Display all breaks.",NULL,NULL) },
239 	{ DDB_ADD_CMD("buf",	db_buf_print_cmd,	0,
240 	    "Print the struct buf at address.", "[/f] address",NULL) },
241 	{ DDB_ADD_CMD("event",	db_event_print_cmd,	0,
242 	    "Print all the non-zero evcnt(9) event counters.", "[/f]",NULL) },
243 	{ DDB_ADD_CMD("lock",	db_lock_print_cmd,	0,NULL,NULL,NULL) },
244 	{ DDB_ADD_CMD("malloc",	db_malloc_print_cmd,0,NULL,NULL,NULL) },
245 	{ DDB_ADD_CMD("map",	db_map_print_cmd,	0,
246 	    "Print the vm_map at address.", "[/f] address",NULL) },
247 	{ DDB_ADD_CMD("mount",	db_mount_print_cmd,	0,
248 	    "Print the mount structure at address.", "[/f] address",NULL) },
249 	{ DDB_ADD_CMD("mbuf",	db_mbuf_print_cmd,	0,NULL,NULL,
250 	    "-c prints all mbuf chains") },
251 	{ DDB_ADD_CMD("ncache",	db_namecache_print_cmd,	0,
252 	    "Dump the namecache list.", "address",NULL) },
253 	{ DDB_ADD_CMD("object",	db_object_print_cmd,	0,
254 	    "Print the vm_object at address.", "[/f] address",NULL) },
255 	{ DDB_ADD_CMD("page",	db_page_print_cmd,	0,
256 	    "Print the vm_page at address.", "[/f] address",NULL) },
257 	{ DDB_ADD_CMD("pool",	db_pool_print_cmd,	0,
258 	    "Print the pool at address.", "[/clp] address",NULL) },
259 	{ DDB_ADD_CMD("registers",	db_show_regs,		0,
260 	    "Display the register set.", "[/u]",NULL) },
261 	{ DDB_ADD_CMD("sched_qs",	db_show_sched_qs,	0,
262 	    "Print the state of the scheduler's run queues.",
263 	    NULL,NULL) },
264 	{ DDB_ADD_CMD("uvmexp",	db_uvmexp_print_cmd, 0,
265 	    "Print a selection of UVM counters and statistics.",
266 	    NULL,NULL) },
267 	{ DDB_ADD_CMD("vnode",	db_vnode_print_cmd,	0,
268 	    "Print the vnode at address.", "[/f] address",NULL) },
269 	{ DDB_ADD_CMD("watches",	db_listwatch_cmd, 	0,
270 	    "Display all watchpoints.", NULL,NULL) },
271 	{ DDB_ADD_CMD(NULL,		NULL,			0,NULL,NULL,NULL) }
272 };
273 
274 /* arch/<arch>/<arch>/db_interface.c */
275 #ifdef DB_MACHINE_COMMANDS
276 extern const struct db_command db_machine_command_table[];
277 #endif
278 
279 static const struct db_command db_command_table[] = {
280 	{ DDB_ADD_CMD("b",		db_breakpoint_cmd,	0,
281 	    "Set a breakpoint at address", "[/u] address[,count].",NULL) },
282 	{ DDB_ADD_CMD("break",	db_breakpoint_cmd,	0,
283 	    "Set a breakpoint at address", "[/u] address[,count].",NULL) },
284 	{ DDB_ADD_CMD("bt",		db_stack_trace_cmd,	0,
285 	    "Show backtrace.", "See help trace.",NULL) },
286 	{ DDB_ADD_CMD("c",		db_continue_cmd,	0,
287 	    "Continue execution.", "[/c]",NULL) },
288 	{ DDB_ADD_CMD("call",	db_fncall,		CS_OWN,
289 	    "Call the function", "address[(expression[,...])]",NULL) },
290 	{ DDB_ADD_CMD("callout",	db_show_callout,	0, NULL,
291 	    NULL,NULL ) },
292 	{ DDB_ADD_CMD("continue",	db_continue_cmd,	0,
293 	    "Continue execution.", "[/c]",NULL) },
294 	{ DDB_ADD_CMD("d",		db_delete_cmd,		0,
295 	    "Delete a breakpoint.", "address | #number",NULL) },
296 	{ DDB_ADD_CMD("delete",	db_delete_cmd,		0,
297 	    "Delete a breakpoint.", "address | #number",NULL) },
298 	{ DDB_ADD_CMD("dmesg",	db_dmesg,		0,
299 	    "Show kernel message buffer.", "[count]",NULL) },
300 	{ DDB_ADD_CMD("dwatch",	db_deletewatch_cmd,	0,
301 	    "Delete the watchpoint.", "address",NULL) },
302 	{ DDB_ADD_CMD("examine",	db_examine_cmd,		CS_SET_DOT,
303 	    "Display the address locations.",
304 	    "[/modifier] address[,count]",NULL) },
305 	{ DDB_ADD_CMD("help",   db_help_print_cmd, CS_OWN|CS_NOREPEAT,
306 	    "Display help about commands",
307 	    "Use other commands as arguments.",NULL) },
308 	{ DDB_ADD_CMD("kill",	db_kill_proc,		CS_OWN,
309 	    "Send a signal to the process","pid[,signal_number]",
310 	    "   pid:\t\t\tthe process id (may need 0t prefix for decimal)\n"
311 	    "   signal_number:\tthe signal to send") },
312 #ifdef KGDB
313 	{ DDB_ADD_CMD("kgdb",	db_kgdb_cmd,	0,	NULL,NULL,NULL) },
314 #endif
315 	{ DDB_ADD_CMD("machine",NULL,CS_MACH,
316 	    "Architecture specific functions.",NULL,NULL) },
317 	{ DDB_ADD_CMD("match",	db_trace_until_matching_cmd,0,
318 	    "Stop at the matching return instruction.","See help next",NULL) },
319 	{ DDB_ADD_CMD("next",	db_trace_until_matching_cmd,0,
320 	    "Stop at the matching return instruction.","[/p]",NULL) },
321 	{ DDB_ADD_CMD("p",		db_print_cmd,		0,
322 	    "Print address according to the format.",
323 	    "[/axzodurc] address [address ...]",NULL) },
324 	{ DDB_ADD_CMD("print",	db_print_cmd,		0,
325 	    "Print address according to the format.",
326 	    "[/axzodurc] address [address ...]",NULL) },
327 	{ DDB_ADD_CMD("ps",		db_show_all_procs,	0,
328 	    "Print all processes.","See show all procs",NULL) },
329 	{ DDB_ADD_CMD("reboot",	db_reboot_cmd,		CS_OWN,
330 	    "Reboot","0x1  RB_ASKNAME, 0x2 RB_SINGLE, 0x4 RB_NOSYNC, 0x8 RB_HALT,"
331 	    "0x40 RB_KDB, 0x100 RB_DUMP, 0x808 RB_POWERDOWN",NULL) },
332 	{ DDB_ADD_CMD("s",		db_single_step_cmd,	0,
333 	    "Single-step count times.","[/p] [,count]",NULL) },
334 	{ DDB_ADD_CMD("search",	db_search_cmd,		CS_OWN|CS_SET_DOT,
335 	    "Search memory from address for value.",
336 	    "[/bhl] address value [mask] [,count]",NULL) },
337 	{ DDB_ADD_CMD("set",	db_set_cmd,		CS_OWN,
338 	    "Set the named variable","$variable [=] expression",NULL) },
339 	{ DDB_ADD_CMD("show",	NULL, CS_SHOW,
340 	    "Show kernel stats.", NULL,NULL) },
341 	{ DDB_ADD_CMD("sifting",	db_sifting_cmd,		CS_OWN,
342 	    "Search the symbol tables ","[/F] string",NULL) },
343 	{ DDB_ADD_CMD("step",	db_single_step_cmd,	0,
344 	    "Single-step count times.","[/p] [,count]",NULL) },
345 	{ DDB_ADD_CMD("sync",	db_sync_cmd,		CS_OWN,
346 	    "Force a crash dump, and then reboot.",NULL,NULL) },
347 	{ DDB_ADD_CMD("trace",	db_stack_trace_cmd,	0,
348 	    "Stack trace from frame-address.",
349 	    "[/u[l]] [frame-address][,count]",NULL) },
350 	{ DDB_ADD_CMD("until",	db_trace_until_call_cmd,0,
351 	    "Stop at the next call or return instruction.","[/p]",NULL) },
352 	{ DDB_ADD_CMD("w",		db_write_cmd,		CS_MORE|CS_SET_DOT,
353 	    "Set a watchpoint for a region. ","address[,size]",NULL) },
354 	{ DDB_ADD_CMD("watch",	db_watchpoint_cmd,	CS_MORE,
355 	    "Set a watchpoint for a region. ","address[,size]",NULL) },
356 	{ DDB_ADD_CMD("whatis",	db_whatis_cmd, 0,
357 	    "Describe what an address is", "address", NULL) },
358 	{ DDB_ADD_CMD("write",	db_write_cmd,		CS_MORE|CS_SET_DOT,
359 	    "Write the expressions at succeeding locations.",
360 	    "[/bhl] address expression [expression ...]",NULL) },
361 	{ DDB_ADD_CMD("x",		db_examine_cmd,		CS_SET_DOT,
362 	    "Display the address locations.",
363 	    "[/modifier] address[,count]",NULL) },
364 	{ DDB_ADD_CMD(NULL, 	NULL,		   0, NULL, NULL, NULL) }
365 };
366 
367 static const struct db_command	*db_last_command = NULL;
368 #if defined(DDB_COMMANDONENTER)
369 char db_cmd_on_enter[DB_LINE_MAXLEN + 1] = ___STRING(DDB_COMMANDONENTER);
370 #else /* defined(DDB_COMMANDONENTER) */
371 char db_cmd_on_enter[DB_LINE_MAXLEN + 1] = "";
372 #endif /* defined(DDB_COMMANDONENTER) */
373 #define	DB_LINE_SEP	';'
374 
375 /*
376  * Utility routine - discard tokens through end-of-line.
377  */
378 void
379 db_skip_to_eol(void)
380 {
381 	int t;
382 
383 	do {
384 		t = db_read_token();
385 	} while (t != tEOL);
386 }
387 
388 void
389 db_error(const char *s)
390 {
391 
392 	if (s)
393 		db_printf("%s", s);
394 	db_flush_lex();
395 	longjmp(db_recover);
396 }
397 
398 /*Execute commandlist after ddb start
399  *This function goes through the command list created from commands and ';'
400  */
401 
402 static void
403 db_execute_commandlist(const char *cmdlist)
404 {
405 	const char *cmd = cmdlist;
406 	const struct db_command	*dummy = NULL;
407 
408 	while (*cmd != '\0') {
409 		const char *ep = cmd;
410 
411 		while (*ep != '\0' && *ep != DB_LINE_SEP) {
412 			ep++;
413 		}
414 		db_set_line(cmd, ep);
415 		db_command(&dummy);
416 		cmd = ep;
417 		if (*cmd == DB_LINE_SEP) {
418 			cmd++;
419 		}
420 	}
421 }
422 
423 /*Initialize ddb command tables*/
424 void
425 db_init_commands(void)
426 {
427 	static bool done = false;
428 
429 	if (done) return;
430 	done = true;
431 
432 	/* register command tables */
433 	(void)db_register_tbl_entry(DDB_BASE_CMD, &db_base_cmd_builtins);
434 #ifdef DB_MACHINE_COMMANDS
435 	(void)db_register_tbl_entry(DDB_MACH_CMD, &db_mach_cmd_builtins);
436 #endif
437 	(void)db_register_tbl_entry(DDB_SHOW_CMD, &db_show_cmd_builtins);
438 }
439 
440 
441 /*
442  * Add command table to the specified list
443  * Arg:
444  * int type specifies type of command table DDB_SHOW_CMD|DDB_BASE_CMD|DDB_MAC_CMD
445  * *cmd_tbl poiter to static allocated db_command table
446  *
447  *Command table must be NULL terminated array of struct db_command
448  */
449 int
450 db_register_tbl(uint8_t type, const struct db_command *cmd_tbl)
451 {
452 	struct db_cmd_tbl_en *list_ent;
453 
454 	if (cmd_tbl->name == 0)
455 		/* empty list - ignore */
456 		return 0;
457 
458 	/* force builtin commands to be registered first */
459 	db_init_commands();
460 
461 	/* now create a list entry for this table */
462 	list_ent = malloc(sizeof(struct db_cmd_tbl_en), M_TEMP, M_ZERO);
463 	if (list_ent == NULL)
464 		return ENOMEM;
465 	list_ent->db_cmd=cmd_tbl;
466 
467 	/* and register it */
468 	return db_register_tbl_entry(type, list_ent);
469 }
470 
471 static int
472 db_register_tbl_entry(uint8_t type, struct db_cmd_tbl_en *list_ent)
473 {
474 	struct db_cmd_tbl_en_head *list;
475 
476 	switch(type) {
477 	case DDB_BASE_CMD:
478 		list = &db_base_cmd_list;
479 		break;
480 	case DDB_SHOW_CMD:
481 		list = &db_show_cmd_list;
482 		break;
483 	case DDB_MACH_CMD:
484 		list = &db_mach_cmd_list;
485 		break;
486 	default:
487 		return ENOENT;
488 	}
489 
490 	TAILQ_INSERT_TAIL(list, list_ent, db_cmd_next);
491 
492 	return 0;
493 }
494 
495 /*
496  * Remove command table specified with db_cmd address == cmd_tbl
497  */
498 int
499 db_unregister_tbl(uint8_t type,const struct db_command *cmd_tbl)
500 {
501 	struct db_cmd_tbl_en *list_ent;
502 	struct db_cmd_tbl_en_head *list;
503 
504 	/* find list on which the entry should live */
505 	switch (type) {
506 	case DDB_BASE_CMD:
507 		list=&db_base_cmd_list;
508 		break;
509 	case DDB_SHOW_CMD:
510 		list=&db_show_cmd_list;
511 		break;
512 	case DDB_MACH_CMD:
513 		list=&db_mach_cmd_list;
514 		break;
515 	default:
516 		return EINVAL;
517 	}
518 
519 	TAILQ_FOREACH (list_ent,list,db_cmd_next) {
520 		if (list_ent->db_cmd == cmd_tbl){
521 			TAILQ_REMOVE(list,
522 			    list_ent,db_cmd_next);
523 			free(list_ent,M_TEMP);
524 			return 0;
525 		}
526 	}
527 	return ENOENT;
528 }
529 
530 /*This function is called from machine trap code.*/
531 void
532 db_command_loop(void)
533 {
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 
564 
565 #ifdef MULTIPROCESSOR
566 		db_printf("db{%ld}> ", (long)cpu_number());
567 #else
568 		db_printf("db> ");
569 #endif
570 		(void) db_read_line();
571 
572 		db_command(&db_last_command);
573 	}
574 
575 	db_recover = savejmp;
576 }
577 
578 /*
579  * Search for command table for command prefix
580  * ret: CMD_UNIQUE    -> completely matches command
581  *      CMD_FOUND     -> matches prefix of single command
582  *      CMD_AMBIGIOUS -> matches prefix of more than one command
583  *      CMD_NONE      -> command not found
584  */
585 static int
586 db_cmd_search(const char *name,const struct db_command *table,
587     const struct db_command **cmdp)
588 {
589 
590 	const struct db_command	*cmd;
591 	int result;
592 
593 	result = CMD_NONE;
594 	*cmdp = NULL;
595 	for (cmd = table; cmd->name != 0; cmd++) {
596 		const char *lp;
597 		const char *rp;
598 
599 		lp = name;
600 		rp = cmd->name;
601 		while (*lp != '\0' && *lp == *rp) {
602 			rp++;
603 			lp++;
604 		}
605 
606 		if (*lp != '\0') /* mismatch or extra chars in name */
607 			continue;
608 
609 		if (*rp == '\0') { /* complete match */
610 			*cmdp = cmd;
611 			return (CMD_UNIQUE);
612 		}
613 
614 		/* prefix match: end of name, not end of command */
615 		if (result == CMD_NONE) {
616 			result = CMD_FOUND;
617 			*cmdp = cmd;
618 		}
619 		else if (result == CMD_FOUND) {
620 			result = CMD_AMBIGUOUS;
621 			*cmdp = NULL;
622 		}
623 	}
624 
625 	return (result);
626 }
627 
628 /*
629  *List commands to the console.
630  */
631 static void
632 db_cmd_list(const struct db_cmd_tbl_en_head *list)
633 {
634 
635 	struct db_cmd_tbl_en *list_ent;
636 	const struct db_command *table;
637 	size_t		i, j, w, columns, lines, numcmds, width=0;
638 	const char	*p;
639 
640 	TAILQ_FOREACH(list_ent,list,db_cmd_next) {
641 		table = list_ent->db_cmd;
642 		for (i = 0; table[i].name != NULL; i++) {
643 			w = strlen(table[i].name);
644 			if (w > width)
645 				width = w;
646 		}
647 	}
648 
649 	width = DB_NEXT_TAB(width);
650 
651 	columns = db_max_width / width;
652 	if (columns == 0)
653 		columns = 1;
654 
655 	TAILQ_FOREACH(list_ent,list,db_cmd_next) {
656 		table = list_ent->db_cmd;
657 
658 		for (numcmds = 0; table[numcmds].name != NULL; numcmds++)
659 			;
660 		lines = (numcmds + columns - 1) / columns;
661 
662 		for (i = 0; i < lines; i++) {
663 			for (j = 0; j < columns; j++) {
664 				p = table[j * lines + i].name;
665 				if (p)
666 					db_printf("%s", p);
667 				if (j * lines + i + lines >= numcmds) {
668 					db_putchar('\n');
669 					break;
670 				}
671 				if (p) {
672 					w = strlen(p);
673 					while (w < width) {
674 						w = DB_NEXT_TAB(w);
675 						db_putchar('\t');
676 					}
677 				}
678 			}
679 		}
680 	}
681 	return;
682 }
683 
684 /*
685  *Returns type of list for command with name *name.
686  */
687 static int
688 db_get_list_type(const char *name)
689 {
690 
691 	const struct db_command    *cmd;
692 	struct db_cmd_tbl_en *list_ent;
693 	int error,ret=-1;
694 
695 	/* search for the command name */
696 	TAILQ_FOREACH(list_ent,&db_base_cmd_list,db_cmd_next) {
697 		/*
698 		 * cmd_search returns CMD_UNIQUE, CMD_FOUND ...
699 		 * CMD_UNIQUE when name was completly matched to cmd->name
700 		 * CMD_FOUND  when name was only partially matched to cmd->name
701 		 * CMD_NONE   command not found in a list
702 		 * CMD_AMBIGIOUS ->more partialy matches
703 		 */
704 
705 		error = db_cmd_search(name, list_ent->db_cmd, &cmd);
706 
707 		if (error == CMD_UNIQUE) {
708 			/* exact match found */
709 			if (cmd->flag == CS_SHOW) {
710 				ret = DDB_SHOW_CMD;
711 				break;
712 			}
713 			if (cmd->flag == CS_MACH) {
714 				ret = DDB_MACH_CMD;
715 				break;
716 			} else {
717 				ret = DDB_BASE_CMD;
718 				break;
719 			}
720 
721 		} else if (error == CMD_FOUND) {
722 			/*
723 			 * partial match, search will continue, but
724 			 * note current result in case we won't
725 			 * find anything better.
726 			 */
727 			if (cmd->flag == CS_SHOW)
728 				ret = DDB_SHOW_CMD;
729 			else if (cmd->flag == CS_MACH)
730 				ret = DDB_MACH_CMD;
731 			else
732 				ret = DDB_BASE_CMD;
733 		}
734 	}
735 
736 	return ret;
737 }
738 
739 /*
740  *Parse command line and execute apropriate function.
741  */
742 static void
743 db_command(const struct db_command **last_cmdp)
744 {
745 	const struct db_command *command;
746 	struct db_cmd_tbl_en *list_ent;
747 	struct db_cmd_tbl_en_head *list;
748 
749 	int		t;
750 	int		result;
751 
752 	char		modif[TOK_STRING_SIZE];
753 	db_expr_t	addr, count;
754 	bool		have_addr = false;
755 
756 	static db_expr_t last_count = 0;
757 
758 	command = NULL;	/* XXX gcc */
759 
760 	t = db_read_token();
761 	if ((t == tEOL) || (t == tCOMMA)) {
762 		/*
763 		 * An empty line repeats last command, at 'next'.
764 		 * Only a count repeats the last command with the new count.
765 		 */
766 		command = *last_cmdp;
767 
768 		if (!command)
769 			return;
770 
771 		addr = (db_expr_t)db_next;
772 		if (t == tCOMMA) {
773 			if (!db_expression(&count)) {
774 				db_printf("Count missing\n");
775 				db_flush_lex();
776 				return;
777 			}
778 		} else
779 			count = last_count;
780 		have_addr = false;
781 		modif[0] = '\0';
782 		db_skip_to_eol();
783 
784 	} else if (t == tEXCL) {
785 		db_fncall(0, 0, 0, NULL);
786 		return;
787 
788 	} else if (t != tIDENT) {
789 		db_printf("?\n");
790 		db_flush_lex();
791 		return;
792 
793 	} else {
794 
795 		switch(db_get_list_type(db_tok_string)) {
796 
797 		case DDB_BASE_CMD:
798 			list = &db_base_cmd_list;
799 			break;
800 
801 		case DDB_SHOW_CMD:
802 			list = &db_show_cmd_list;
803 			/* need to read show subcommand if show command list
804 			   is used. */
805 			t = db_read_token();
806 
807 			if (t != tIDENT) {
808 				/* if only show command is executed, print
809 				   all subcommands */
810 				db_cmd_list(list);
811 				db_flush_lex();
812 				return;
813 			}
814 			break;
815 		case DDB_MACH_CMD:
816 			list = &db_mach_cmd_list;
817 			/* need to read machine subcommand if
818 			  machine level 2 command list is used. */
819 			t = db_read_token();
820 
821 			if (t != tIDENT) {
822 				/* if only show command is executed, print
823 				   all subcommands */
824 				db_cmd_list(list);
825 				db_flush_lex();
826 				return;
827 			}
828 			break;
829 		default:
830 			db_printf("No such command\n");
831 			db_flush_lex();
832 			return;
833 		}
834 
835  COMPAT_RET:
836 		TAILQ_FOREACH(list_ent, list, db_cmd_next) {
837 			result = db_cmd_search(db_tok_string, list_ent->db_cmd,
838 			    &command);
839 
840 			/* after CMD_UNIQUE in cmd_list only a single command
841 			   name is possible */
842 			if (result == CMD_UNIQUE)
843 				break;
844 
845 		}
846 
847                 /* check compatibility flag */
848 		if (command && command->flag & CS_COMPAT){
849 			t = db_read_token();
850 			if (t != tIDENT) {
851 					db_cmd_list(list);
852 					db_flush_lex();
853 					return;
854 			}
855 
856 			/* support only level 2 commands here */
857 			goto COMPAT_RET;
858 		}
859 
860 		if (!command) {
861 			db_printf("No such command\n");
862 			db_flush_lex();
863 			return;
864 		}
865 
866 		if ((command->flag & CS_OWN) == 0) {
867 
868 			/*
869 			 * Standard syntax:
870 			 * command [/modifier] [addr] [,count]
871 			 */
872 			t = db_read_token(); /* get modifier */
873 			if (t == tSLASH) {
874 				t = db_read_token();
875 				if (t != tIDENT) {
876 					db_printf("Bad modifier\n");
877 					db_flush_lex();
878 					return;
879 				}
880 				/* save modifier */
881 				strlcpy(modif, db_tok_string, sizeof(modif));
882 
883 			} else {
884 				db_unread_token(t);
885 				modif[0] = '\0';
886 			}
887 
888 			if (db_expression(&addr)) { /*get address*/
889 				db_dot = (db_addr_t) addr;
890 				db_last_addr = db_dot;
891 				have_addr = true;
892 			} else {
893 				addr = (db_expr_t) db_dot;
894 				have_addr = false;
895 			}
896 
897 			t = db_read_token();
898 			if (t == tCOMMA) { /*Get count*/
899 				if (!db_expression(&count)) {
900 					db_printf("Count missing\n");
901 					db_flush_lex();
902 					return;
903 				}
904 			} else {
905 				db_unread_token(t);
906 				count = -1;
907 			}
908 			if ((command->flag & CS_MORE) == 0) {
909 				db_skip_to_eol();
910 			}
911 		}
912 	}
913 
914 	if (command->flag & CS_NOREPEAT) {
915 		*last_cmdp = NULL;
916 		last_count = 0;
917 	} else {
918 		*last_cmdp = command;
919 		last_count = count;
920 	}
921 
922 	if (command != NULL) {
923 		/*
924 		 * Execute the command.
925 		 */
926 		if (command->fcn != NULL)
927 			(*command->fcn)(addr, have_addr, count, modif);
928 
929 		if (command->flag & CS_SET_DOT) {
930 			/*
931 			 * If command changes dot, set dot to
932 			 * previous address displayed (if 'ed' style).
933 			 */
934 			if (db_ed_style)
935 				db_dot = db_prev;
936 			else
937 				db_dot = db_next;
938 		} else {
939 			/*
940 			 * If command does not change dot,
941 			 * set 'next' location to be the same.
942 			 */
943 			db_next = db_dot;
944 		}
945 	}
946 }
947 
948 /*
949  * Print help for commands
950  */
951 static void
952 db_help_print_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
953     const char *modif)
954 {
955 
956 	const struct db_cmd_tbl_en_head *list;
957 	const struct db_cmd_tbl_en *list_ent;
958 	const struct db_command *help = NULL;
959 	int t, result;
960 
961 	t = db_read_token();
962 	/* is there another command after the "help"? */
963 	if (t == tIDENT){
964 
965 		switch(db_get_list_type(db_tok_string)) {
966 
967 		case DDB_BASE_CMD:
968 			list=&db_base_cmd_list;
969 			break;
970 		case DDB_SHOW_CMD:
971 			list=&db_show_cmd_list;
972 			/* read the show subcommand */
973 			t = db_read_token();
974 
975 			if (t != tIDENT) {
976 				/* no subcommand, print the list */
977 				db_cmd_list(list);
978 				db_flush_lex();
979 				return;
980 			}
981 
982 			break;
983 		case DDB_MACH_CMD:
984 			list=&db_mach_cmd_list;
985 			/* read machine subcommand */
986 			t = db_read_token();
987 
988 			if (t != tIDENT) {
989 				/* no subcommand - just print the list */
990 				db_cmd_list(list);
991 				db_flush_lex();
992 				return;
993 			}
994 			break;
995 
996 		default:
997 			db_printf("No such command\n");
998 			db_flush_lex();
999 			return;
1000 		}
1001  COMPAT_RET:
1002 		TAILQ_FOREACH(list_ent,list,db_cmd_next){
1003 			result = db_cmd_search(db_tok_string, list_ent->db_cmd,
1004 					&help);
1005 			/* after CMD_UNIQUE only a single command
1006 			   name is possible */
1007 			if (result == CMD_UNIQUE)
1008 				break;
1009 		}
1010 #ifdef DDB_VERBOSE_HELP
1011 		/*print help*/
1012 
1013 		db_printf("Command: %s\n",help->name);
1014 
1015 		if (help->cmd_descr != NULL)
1016 			db_printf(" Description: %s\n",help->cmd_descr);
1017 
1018 		if (help->cmd_arg != NULL)
1019 			db_printf(" Arguments: %s\n",help->cmd_arg);
1020 
1021 		if (help->cmd_arg_help != NULL)
1022 			db_printf(" Arguments description:\n%s\n",
1023 			    help->cmd_arg_help);
1024 
1025 		if ((help->cmd_arg == NULL) && (help->cmd_descr == NULL))
1026 			db_printf("%s Doesn't have any help message included.\n",
1027 			    help->name);
1028 #endif
1029 		/* check compatibility flag */
1030 		/*
1031 		 * The "show all" command table has been merged with the
1032 		 * "show" command table - but we want to keep the old UI
1033 		 * available. So if we find a CS_COMPAT entry, we read
1034 		 * the next token and try again.
1035 		 */
1036 		if (help->flag == CS_COMPAT){
1037 			t = db_read_token();
1038 
1039 			if (t != tIDENT){
1040 				db_cmd_list(list);
1041 				db_flush_lex();
1042 				return;
1043 			}
1044 
1045 			goto COMPAT_RET;
1046 			/* support only level 2 commands here */
1047 		} else {
1048 			db_skip_to_eol();
1049 		}
1050 
1051 	} else /* t != tIDENT */
1052 		/* print base commands */
1053 		db_cmd_list(&db_base_cmd_list);
1054 
1055 	return;
1056 }
1057 
1058 /*ARGSUSED*/
1059 static void
1060 db_map_print_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
1061     const char *modif)
1062 {
1063 	bool full = false;
1064 
1065 	if (modif[0] == 'f')
1066 		full = true;
1067 
1068 	if (have_addr == false)
1069 		addr = (db_expr_t)(intptr_t) kernel_map;
1070 
1071 	uvm_map_printit((struct vm_map *)(intptr_t) addr, full, db_printf);
1072 }
1073 
1074 /*ARGSUSED*/
1075 static void
1076 db_malloc_print_cmd(db_expr_t addr, bool have_addr,
1077     db_expr_t count, const char *modif)
1078 {
1079 
1080 #ifdef MALLOC_DEBUG
1081 	if (!have_addr)
1082 		addr = 0;
1083 
1084 	debug_malloc_printit(db_printf, (vaddr_t) addr);
1085 #else
1086 	db_printf("The kernel is not built with the MALLOC_DEBUG option.\n");
1087 #endif /* MALLOC_DEBUG */
1088 }
1089 
1090 /*ARGSUSED*/
1091 static void
1092 db_object_print_cmd(db_expr_t addr, bool have_addr,
1093     db_expr_t count, const char *modif)
1094 {
1095 	bool full = false;
1096 
1097 	if (modif[0] == 'f')
1098 		full = true;
1099 
1100 	uvm_object_printit((struct uvm_object *)(intptr_t) addr, full,
1101 	    db_printf);
1102 }
1103 
1104 /*ARGSUSED*/
1105 static void
1106 db_page_print_cmd(db_expr_t addr, bool have_addr,
1107     db_expr_t count, const char *modif)
1108 {
1109 	bool full = false;
1110 
1111 	if (modif[0] == 'f')
1112 		full = true;
1113 
1114 	uvm_page_printit((struct vm_page *)(intptr_t) addr, full, db_printf);
1115 }
1116 
1117 /*ARGSUSED*/
1118 static void
1119 db_show_all_pages(db_expr_t addr, bool have_addr,
1120     db_expr_t count, const char *modif)
1121 {
1122 
1123 	uvm_page_printall(db_printf);
1124 }
1125 
1126 /*ARGSUSED*/
1127 static void
1128 db_buf_print_cmd(db_expr_t addr, bool have_addr,
1129     db_expr_t count, const char *modif)
1130 {
1131 	bool full = false;
1132 
1133 	if (modif[0] == 'f')
1134 		full = true;
1135 
1136 	vfs_buf_print((struct buf *)(intptr_t) addr, full, db_printf);
1137 }
1138 
1139 /*ARGSUSED*/
1140 static void
1141 db_event_print_cmd(db_expr_t addr, bool have_addr,
1142     db_expr_t count, const char *modif)
1143 {
1144 	bool full = false;
1145 
1146 	if (modif[0] == 'f')
1147 		full = true;
1148 
1149 	event_print(full, db_printf);
1150 }
1151 
1152 /*ARGSUSED*/
1153 static void
1154 db_vnode_print_cmd(db_expr_t addr, bool have_addr,
1155     db_expr_t count, const char *modif)
1156 {
1157 	bool full = false;
1158 
1159 	if (modif[0] == 'f')
1160 		full = true;
1161 
1162 	vfs_vnode_print((struct vnode *)(intptr_t) addr, full, db_printf);
1163 }
1164 
1165 static void
1166 db_mount_print_cmd(db_expr_t addr, bool have_addr,
1167     db_expr_t count, const char *modif)
1168 {
1169 	bool full = false;
1170 
1171 	if (modif[0] == 'f')
1172 		full = true;
1173 
1174 	vfs_mount_print((struct mount *)(intptr_t) addr, full, db_printf);
1175 }
1176 
1177 /*ARGSUSED*/
1178 static void
1179 db_mbuf_print_cmd(db_expr_t addr, bool have_addr,
1180     db_expr_t count, const char *modif)
1181 {
1182 
1183 	m_print((const struct mbuf *)(intptr_t) addr, modif, db_printf);
1184 }
1185 
1186 /*ARGSUSED*/
1187 static void
1188 db_pool_print_cmd(db_expr_t addr, bool have_addr,
1189     db_expr_t count, const char *modif)
1190 {
1191 
1192 	pool_printit((struct pool *)(intptr_t) addr, modif, db_printf);
1193 }
1194 
1195 /*ARGSUSED*/
1196 static void
1197 db_namecache_print_cmd(db_expr_t addr, bool have_addr,
1198     db_expr_t count, const char *modif)
1199 {
1200 
1201 	namecache_print((struct vnode *)(intptr_t) addr, db_printf);
1202 }
1203 
1204 /*ARGSUSED*/
1205 static void
1206 db_uvmexp_print_cmd(db_expr_t addr, bool have_addr,
1207     db_expr_t count, const char *modif)
1208 {
1209 
1210 	uvmexp_print(db_printf);
1211 }
1212 
1213 /*ARGSUSED*/
1214 static void
1215 db_lock_print_cmd(db_expr_t addr, bool have_addr,
1216     db_expr_t count, const char *modif)
1217 {
1218 
1219 	lockdebug_lock_print((void *)addr, db_printf);
1220 }
1221 
1222 /*
1223  * Call random function:
1224  * !expr(arg,arg,arg)
1225  */
1226 /*ARGSUSED*/
1227 static void
1228 db_fncall(db_expr_t addr, bool have_addr,
1229     db_expr_t count, const char *modif)
1230 {
1231 	db_expr_t	fn_addr;
1232 #define	MAXARGS		11
1233 	db_expr_t	args[MAXARGS];
1234 	int		nargs = 0;
1235 	db_expr_t	retval;
1236 	db_expr_t	(*func)(db_expr_t, ...);
1237 	int		t;
1238 
1239 	if (!db_expression(&fn_addr)) {
1240 		db_printf("Bad function\n");
1241 		db_flush_lex();
1242 		return;
1243 	}
1244 	func = (db_expr_t (*)(db_expr_t, ...))(intptr_t) fn_addr;
1245 
1246 	t = db_read_token();
1247 	if (t == tLPAREN) {
1248 		if (db_expression(&args[0])) {
1249 			nargs++;
1250 			while ((t = db_read_token()) == tCOMMA) {
1251 				if (nargs == MAXARGS) {
1252 					db_printf("Too many arguments\n");
1253 					db_flush_lex();
1254 					return;
1255 				}
1256 				if (!db_expression(&args[nargs])) {
1257 					db_printf("Argument missing\n");
1258 					db_flush_lex();
1259 					return;
1260 				}
1261 				nargs++;
1262 			}
1263 			db_unread_token(t);
1264 		}
1265 		if (db_read_token() != tRPAREN) {
1266 			db_printf("?\n");
1267 			db_flush_lex();
1268 			return;
1269 		}
1270 	}
1271 	db_skip_to_eol();
1272 
1273 	while (nargs < MAXARGS) {
1274 		args[nargs++] = 0;
1275 	}
1276 
1277 	retval = (*func)(args[0], args[1], args[2], args[3], args[4],
1278 			 args[5], args[6], args[7], args[8], args[9]);
1279 	db_printf("%s\n", db_num_to_str(retval));
1280 }
1281 
1282 static void
1283 db_reboot_cmd(db_expr_t addr, bool have_addr,
1284     db_expr_t count, const char *modif)
1285 {
1286 	db_expr_t bootflags;
1287 
1288 	/* Flags, default to RB_AUTOBOOT */
1289 	if (!db_expression(&bootflags))
1290 		bootflags = (db_expr_t)RB_AUTOBOOT;
1291 	if (db_read_token() != tEOL) {
1292 		db_error("?\n");
1293 		/*NOTREACHED*/
1294 	}
1295 	/*
1296 	 * We are leaving DDB, never to return upward.
1297 	 * Clear db_recover so that we can debug faults in functions
1298 	 * called from cpu_reboot.
1299 	 */
1300 	db_recover = 0;
1301 	cpu_reboot((int)bootflags, NULL);
1302 }
1303 
1304 static void
1305 db_sifting_cmd(db_expr_t addr, bool have_addr,
1306     db_expr_t count, const char *modif)
1307 {
1308 	int	mode, t;
1309 
1310 	t = db_read_token();
1311 	if (t == tSLASH) {
1312 		t = db_read_token();
1313 		if (t != tIDENT) {
1314 			bad_modifier:
1315 			db_printf("Bad modifier\n");
1316 			db_flush_lex();
1317 			return;
1318 		}
1319 		if (!strcmp(db_tok_string, "F"))
1320 			mode = 'F';
1321 		else
1322 			goto bad_modifier;
1323 		t = db_read_token();
1324 	} else
1325 		mode = 0;
1326 
1327 	if (t == tIDENT)
1328 		db_sifting(db_tok_string, mode);
1329 	else {
1330 		db_printf("Bad argument (non-string)\n");
1331 		db_flush_lex();
1332 	}
1333 }
1334 
1335 static void
1336 db_stack_trace_cmd(db_expr_t addr, bool have_addr, db_expr_t count, const char *modif)
1337 {
1338 	register const char *cp = modif;
1339 	register char c;
1340 	void (*pr)(const char *, ...);
1341 
1342 	pr = db_printf;
1343 	while ((c = *cp++) != 0)
1344 		if (c == 'l')
1345 			pr = printf;
1346 
1347 	if (count == -1)
1348 		count = 65535;
1349 
1350 	db_stack_trace_print(addr, have_addr, count, modif, pr);
1351 }
1352 
1353 static void
1354 db_sync_cmd(db_expr_t addr, bool have_addr,
1355     db_expr_t count, const char *modif)
1356 {
1357 
1358 	/*
1359 	 * We are leaving DDB, never to return upward.
1360 	 * Clear db_recover so that we can debug faults in functions
1361 	 * called from cpu_reboot.
1362 	 */
1363 	db_recover = 0;
1364 	cpu_reboot(RB_DUMP, NULL);
1365 }
1366 
1367 /*
1368  * Describe what an address is
1369  */
1370 void
1371 db_whatis_cmd(db_expr_t address, bool have_addr,
1372     db_expr_t count, const char *modif)
1373 {
1374 	const uintptr_t addr = (uintptr_t)address;
1375 
1376 	lwp_whatis(addr, db_printf);
1377 	pool_whatis(addr, db_printf);
1378 	vmem_whatis(addr, db_printf);
1379 	uvm_whatis(addr, db_printf);
1380 }
1381