db_command.c revision 163192 
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: head/sys/ddb/db_command.c 163192 2006-10-10 07:26:54Z bde $");
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/watchdog.h>
48
49#include <ddb/ddb.h>
50#include <ddb/db_command.h>
51#include <ddb/db_lex.h>
52#include <ddb/db_output.h>
53
54#include <machine/cpu.h>
55#include <machine/setjmp.h>
56
57/*
58 * Exported global variables
59 */
60boolean_t	db_cmd_loop_done;
61db_addr_t	db_dot;
62db_addr_t	db_last_addr;
63db_addr_t	db_prev;
64db_addr_t	db_next;
65
66SET_DECLARE(db_cmd_set, struct command);
67SET_DECLARE(db_show_cmd_set, struct command);
68
69static db_cmdfcn_t	db_fncall;
70static db_cmdfcn_t	db_gdb;
71static db_cmdfcn_t	db_halt;
72static db_cmdfcn_t	db_kill;
73static db_cmdfcn_t	db_reset;
74static db_cmdfcn_t	db_stack_trace;
75static db_cmdfcn_t	db_stack_trace_all;
76static db_cmdfcn_t	db_watchdog;
77
78/*
79 * 'show' commands
80 */
81
82static struct command db_show_all_cmds[] = {
83	{ "procs",	db_ps,			0,	0 },
84	{ (char *)0 }
85};
86
87static struct command_table db_show_all_table = {
88	db_show_all_cmds
89};
90
91static struct command db_show_cmds[] = {
92	{ "all",	0,			0,	&db_show_all_table },
93	{ "registers",	db_show_regs,		0,	0 },
94	{ "breaks",	db_listbreak_cmd, 	0,	0 },
95	{ "threads",	db_show_threads,	0,	0 },
96	{ (char *)0, }
97};
98
99static struct command_table db_show_table = {
100	db_show_cmds,
101	SET_BEGIN(db_show_cmd_set),
102	SET_LIMIT(db_show_cmd_set)
103};
104
105static struct command db_commands[] = {
106	{ "print",	db_print_cmd,		0,	0 },
107	{ "p",		db_print_cmd,		0,	0 },
108	{ "examine",	db_examine_cmd,		CS_SET_DOT, 0 },
109	{ "x",		db_examine_cmd,		CS_SET_DOT, 0 },
110	{ "search",	db_search_cmd,		CS_OWN|CS_SET_DOT, 0 },
111	{ "set",	db_set_cmd,		CS_OWN,	0 },
112	{ "write",	db_write_cmd,		CS_MORE|CS_SET_DOT, 0 },
113	{ "w",		db_write_cmd,		CS_MORE|CS_SET_DOT, 0 },
114	{ "delete",	db_delete_cmd,		0,	0 },
115	{ "d",		db_delete_cmd,		0,	0 },
116	{ "break",	db_breakpoint_cmd,	0,	0 },
117	{ "b",		db_breakpoint_cmd,	0,	0 },
118	{ "dwatch",	db_deletewatch_cmd,	0,	0 },
119	{ "watch",	db_watchpoint_cmd,	CS_MORE,0 },
120	{ "dhwatch",	db_deletehwatch_cmd,	0,      0 },
121	{ "hwatch",	db_hwatchpoint_cmd,	0,      0 },
122	{ "step",	db_single_step_cmd,	0,	0 },
123	{ "s",		db_single_step_cmd,	0,	0 },
124	{ "continue",	db_continue_cmd,	0,	0 },
125	{ "c",		db_continue_cmd,	0,	0 },
126	{ "until",	db_trace_until_call_cmd,0,	0 },
127	{ "next",	db_trace_until_matching_cmd,0,	0 },
128	{ "match",	db_trace_until_matching_cmd,0,	0 },
129	{ "trace",	db_stack_trace,		CS_OWN,	0 },
130	{ "t",		db_stack_trace,		CS_OWN,	0 },
131	{ "alltrace",	db_stack_trace_all,	0,	0 },
132	{ "where",	db_stack_trace,		CS_OWN,	0 },
133	{ "bt",		db_stack_trace,		CS_OWN,	0 },
134	{ "call",	db_fncall,		CS_OWN,	0 },
135	{ "show",	0,			0,	&db_show_table },
136	{ "ps",		db_ps,			0,	0 },
137	{ "gdb",	db_gdb,			0,	0 },
138	{ "halt",	db_halt,		0,	0 },
139	{ "reboot",	db_reset,		0,	0 },
140	{ "reset",	db_reset,		0,	0 },
141	{ "kill",	db_kill,		CS_OWN,	0 },
142	{ "watchdog",	db_watchdog,		0,	0 },
143	{ "thread",	db_set_thread,		CS_OWN,	0 },
144	{ (char *)0, }
145};
146
147static struct command_table db_command_table = {
148	db_commands,
149	SET_BEGIN(db_cmd_set),
150	SET_LIMIT(db_cmd_set)
151};
152
153static struct command	*db_last_command = 0;
154
155/*
156 * if 'ed' style: 'dot' is set at start of last item printed,
157 * and '+' points to next line.
158 * Otherwise: 'dot' points to next item, '..' points to last.
159 */
160static boolean_t	db_ed_style = TRUE;
161
162/*
163 * Utility routine - discard tokens through end-of-line.
164 */
165void
166db_skip_to_eol()
167{
168	int	t;
169	do {
170	    t = db_read_token();
171	} while (t != tEOL);
172}
173
174/*
175 * Results of command search.
176 */
177#define	CMD_UNIQUE	0
178#define	CMD_FOUND	1
179#define	CMD_NONE	2
180#define	CMD_AMBIGUOUS	3
181#define	CMD_HELP	4
182
183static void	db_cmd_match(char *name, struct command *cmd,
184		    struct command **cmdp, int *resultp);
185static void	db_cmd_list(struct command_table *table);
186static int	db_cmd_search(char *name, struct command_table *table,
187		    struct command **cmdp);
188static void	db_command(struct command **last_cmdp,
189		    struct command_table *cmd_table);
190
191/*
192 * Helper function to match a single command.
193 */
194static void
195db_cmd_match(name, cmd, cmdp, resultp)
196	char *		name;
197	struct command	*cmd;
198	struct command	**cmdp;	/* out */
199	int *		resultp;
200{
201	char *lp, *rp;
202	int c;
203
204	lp = name;
205	rp = cmd->name;
206	while ((c = *lp) == *rp) {
207		if (c == 0) {
208			/* complete match */
209			*cmdp = cmd;
210			*resultp = CMD_UNIQUE;
211			return;
212		}
213		lp++;
214		rp++;
215	}
216	if (c == 0) {
217		/* end of name, not end of command -
218		   partial match */
219		if (*resultp == CMD_FOUND) {
220			*resultp = CMD_AMBIGUOUS;
221			/* but keep looking for a full match -
222			   this lets us match single letters */
223		} else {
224			*cmdp = cmd;
225			*resultp = CMD_FOUND;
226		}
227	}
228}
229
230/*
231 * Search for command prefix.
232 */
233static int
234db_cmd_search(name, table, cmdp)
235	char *		name;
236	struct command_table *table;
237	struct command	**cmdp;	/* out */
238{
239	struct command	*cmd;
240	struct command	**aux_cmdp;
241	int		result = CMD_NONE;
242
243	for (cmd = table->table; cmd->name != 0; cmd++) {
244		db_cmd_match(name, cmd, cmdp, &result);
245		if (result == CMD_UNIQUE)
246			return (CMD_UNIQUE);
247	}
248	if (table->aux_tablep != NULL)
249		for (aux_cmdp = table->aux_tablep;
250		     aux_cmdp < table->aux_tablep_end;
251		     aux_cmdp++) {
252			db_cmd_match(name, *aux_cmdp, cmdp, &result);
253			if (result == CMD_UNIQUE)
254				return (CMD_UNIQUE);
255		}
256	if (result == CMD_NONE) {
257		/* check for 'help' */
258		if (name[0] == 'h' && name[1] == 'e'
259		    && name[2] == 'l' && name[3] == 'p')
260			result = CMD_HELP;
261	}
262	return (result);
263}
264
265static void
266db_cmd_list(table)
267	struct command_table *table;
268{
269	register struct command *cmd;
270	register struct command **aux_cmdp;
271
272	for (cmd = table->table; cmd->name != 0; cmd++) {
273	    db_printf("%-12s", cmd->name);
274	    db_end_line(12);
275	}
276	if (table->aux_tablep == NULL)
277	    return;
278	for (aux_cmdp = table->aux_tablep; aux_cmdp < table->aux_tablep_end;
279	     aux_cmdp++) {
280	    db_printf("%-12s", (*aux_cmdp)->name);
281	    db_end_line(12);
282	}
283}
284
285static void
286db_command(last_cmdp, cmd_table)
287	struct command	**last_cmdp;	/* IN_OUT */
288	struct command_table *cmd_table;
289{
290	struct command	*cmd;
291	int		t;
292	char		modif[TOK_STRING_SIZE];
293	db_expr_t	addr, count;
294	boolean_t	have_addr = FALSE;
295	int		result;
296
297	t = db_read_token();
298	if (t == tEOL) {
299	    /* empty line repeats last command, at 'next' */
300	    cmd = *last_cmdp;
301	    addr = (db_expr_t)db_next;
302	    have_addr = FALSE;
303	    count = 1;
304	    modif[0] = '\0';
305	}
306	else if (t == tEXCL) {
307	    db_fncall((db_expr_t)0, (boolean_t)0, (db_expr_t)0, (char *)0);
308	    return;
309	}
310	else if (t != tIDENT) {
311	    db_printf("?\n");
312	    db_flush_lex();
313	    return;
314	}
315	else {
316	    /*
317	     * Search for command
318	     */
319	    while (cmd_table) {
320		result = db_cmd_search(db_tok_string,
321				       cmd_table,
322				       &cmd);
323		switch (result) {
324		    case CMD_NONE:
325			db_printf("No such command\n");
326			db_flush_lex();
327			return;
328		    case CMD_AMBIGUOUS:
329			db_printf("Ambiguous\n");
330			db_flush_lex();
331			return;
332		    case CMD_HELP:
333			db_cmd_list(cmd_table);
334			db_flush_lex();
335			return;
336		    default:
337			break;
338		}
339		if ((cmd_table = cmd->more) != NULL) {
340		    t = db_read_token();
341		    if (t != tIDENT) {
342			db_cmd_list(cmd_table);
343			db_flush_lex();
344			return;
345		    }
346		}
347	    }
348
349	    if ((cmd->flag & CS_OWN) == 0) {
350		/*
351		 * Standard syntax:
352		 * command [/modifier] [addr] [,count]
353		 */
354		t = db_read_token();
355		if (t == tSLASH) {
356		    t = db_read_token();
357		    if (t != tIDENT) {
358			db_printf("Bad modifier\n");
359			db_flush_lex();
360			return;
361		    }
362		    db_strcpy(modif, db_tok_string);
363		}
364		else {
365		    db_unread_token(t);
366		    modif[0] = '\0';
367		}
368
369		if (db_expression(&addr)) {
370		    db_dot = (db_addr_t) addr;
371		    db_last_addr = db_dot;
372		    have_addr = TRUE;
373		}
374		else {
375		    addr = (db_expr_t) db_dot;
376		    have_addr = FALSE;
377		}
378		t = db_read_token();
379		if (t == tCOMMA) {
380		    if (!db_expression(&count)) {
381			db_printf("Count missing\n");
382			db_flush_lex();
383			return;
384		    }
385		}
386		else {
387		    db_unread_token(t);
388		    count = -1;
389		}
390		if ((cmd->flag & CS_MORE) == 0) {
391		    db_skip_to_eol();
392		}
393	    }
394	}
395	*last_cmdp = cmd;
396	if (cmd != 0) {
397	    /*
398	     * Execute the command.
399	     */
400	    db_enable_pager();
401	    (*cmd->fcn)(addr, have_addr, count, modif);
402	    db_disable_pager();
403
404	    if (cmd->flag & CS_SET_DOT) {
405		/*
406		 * If command changes dot, set dot to
407		 * previous address displayed (if 'ed' style).
408		 */
409		if (db_ed_style) {
410		    db_dot = db_prev;
411		}
412		else {
413		    db_dot = db_next;
414		}
415	    }
416	    else {
417		/*
418		 * If command does not change dot,
419		 * set 'next' location to be the same.
420		 */
421		db_next = db_dot;
422	    }
423	}
424}
425
426/*
427 * At least one non-optional command must be implemented using
428 * DB_COMMAND() so that db_cmd_set gets created.  Here is one.
429 */
430DB_COMMAND(panic, db_panic)
431{
432	db_disable_pager();
433	panic("from debugger");
434}
435
436void
437db_command_loop()
438{
439	/*
440	 * Initialize 'prev' and 'next' to dot.
441	 */
442	db_prev = db_dot;
443	db_next = db_dot;
444
445	db_cmd_loop_done = 0;
446	while (!db_cmd_loop_done) {
447	    if (db_print_position() != 0)
448		db_printf("\n");
449
450	    db_printf("db> ");
451	    (void) db_read_line();
452
453	    db_command(&db_last_command, &db_command_table);
454	}
455}
456
457void
458db_error(s)
459	const char *s;
460{
461	if (s)
462	    db_printf("%s", s);
463	db_flush_lex();
464	kdb_reenter();
465}
466
467
468/*
469 * Call random function:
470 * !expr(arg,arg,arg)
471 */
472
473/* The generic implementation supports a maximum of 10 arguments. */
474typedef db_expr_t __db_f(db_expr_t, db_expr_t, db_expr_t, db_expr_t,
475    db_expr_t, db_expr_t, db_expr_t, db_expr_t, db_expr_t, db_expr_t);
476
477static __inline int
478db_fncall_generic(db_expr_t addr, db_expr_t *rv, int nargs, db_expr_t args[])
479{
480	__db_f *f = (__db_f *)addr;
481
482	if (nargs > 10) {
483		db_printf("Too many arguments (max 10)\n");
484		return (0);
485	}
486	*rv = (*f)(args[0], args[1], args[2], args[3], args[4], args[5],
487	    args[6], args[7], args[8], args[9]);
488	return (1);
489}
490
491static void
492db_fncall(dummy1, dummy2, dummy3, dummy4)
493	db_expr_t	dummy1;
494	boolean_t	dummy2;
495	db_expr_t	dummy3;
496	char *		dummy4;
497{
498	db_expr_t	fn_addr;
499	db_expr_t	args[DB_MAXARGS];
500	int		nargs = 0;
501	db_expr_t	retval;
502	int		t;
503
504	if (!db_expression(&fn_addr)) {
505	    db_printf("Bad function\n");
506	    db_flush_lex();
507	    return;
508	}
509
510	t = db_read_token();
511	if (t == tLPAREN) {
512	    if (db_expression(&args[0])) {
513		nargs++;
514		while ((t = db_read_token()) == tCOMMA) {
515		    if (nargs == DB_MAXARGS) {
516			db_printf("Too many arguments (max %d)\n", DB_MAXARGS);
517			db_flush_lex();
518			return;
519		    }
520		    if (!db_expression(&args[nargs])) {
521			db_printf("Argument missing\n");
522			db_flush_lex();
523			return;
524		    }
525		    nargs++;
526		}
527		db_unread_token(t);
528	    }
529	    if (db_read_token() != tRPAREN) {
530		db_printf("?\n");
531		db_flush_lex();
532		return;
533	    }
534	}
535	db_skip_to_eol();
536	db_disable_pager();
537
538	if (DB_CALL(fn_addr, &retval, nargs, args))
539		db_printf("= %#lr\n", (long)retval);
540}
541
542static void
543db_halt(db_expr_t dummy, boolean_t dummy2, db_expr_t dummy3, char *dummy4)
544{
545
546	cpu_halt();
547}
548
549static void
550db_kill(dummy1, dummy2, dummy3, dummy4)
551	db_expr_t	dummy1;
552	boolean_t	dummy2;
553	db_expr_t	dummy3;
554	char *		dummy4;
555{
556	db_expr_t old_radix, pid, sig;
557	struct proc *p;
558
559#define DB_ERROR(f)	do { db_printf f; db_flush_lex(); goto out; } while (0)
560
561	/*
562	 * PIDs and signal numbers are typically represented in base
563	 * 10, so make that the default here.  It can, of course, be
564	 * overridden by specifying a prefix.
565	 */
566	old_radix = db_radix;
567	db_radix = 10;
568	/* Retrieve arguments. */
569	if (!db_expression(&sig))
570		DB_ERROR(("Missing signal number\n"));
571	if (!db_expression(&pid))
572		DB_ERROR(("Missing process ID\n"));
573	db_skip_to_eol();
574	if (sig < 0 || sig > _SIG_MAXSIG)
575		DB_ERROR(("Signal number out of range\n"));
576
577	/*
578	 * Find the process in question.  allproc_lock is not needed
579	 * since we're in DDB.
580	 */
581	/* sx_slock(&allproc_lock); */
582	LIST_FOREACH(p, &allproc, p_list)
583	    if (p->p_pid == pid)
584		    break;
585	/* sx_sunlock(&allproc_lock); */
586	if (p == NULL)
587		DB_ERROR(("Can't find process with pid %ld\n", (long) pid));
588
589	/* If it's already locked, bail; otherwise, do the deed. */
590	if (PROC_TRYLOCK(p) == 0)
591		DB_ERROR(("Can't lock process with pid %ld\n", (long) pid));
592	else {
593		psignal(p, sig);
594		PROC_UNLOCK(p);
595	}
596
597out:
598	db_radix = old_radix;
599#undef DB_ERROR
600}
601
602static void
603db_reset(dummy1, dummy2, dummy3, dummy4)
604	db_expr_t	dummy1;
605	boolean_t	dummy2;
606	db_expr_t	dummy3;
607	char *		dummy4;
608{
609
610	cpu_reset();
611}
612
613static void
614db_watchdog(dummy1, dummy2, dummy3, dummy4)
615	db_expr_t	dummy1;
616	boolean_t	dummy2;
617	db_expr_t	dummy3;
618	char *		dummy4;
619{
620	int i;
621
622	/*
623	 * XXX: It might make sense to be able to set the watchdog to a
624	 * XXX: timeout here so that failure or hang as a result of subsequent
625	 * XXX: ddb commands could be recovered by a reset.
626	 */
627
628	EVENTHANDLER_INVOKE(watchdog_list, 0, &i);
629}
630
631static void
632db_gdb(db_expr_t dummy1, boolean_t dummy2, db_expr_t dummy3, char *dummy4)
633{
634
635	if (kdb_dbbe_select("gdb") != 0)
636		db_printf("The remote GDB backend could not be selected.\n");
637	else
638		db_printf("Step to enter the remote GDB backend.\n");
639}
640
641static void
642db_stack_trace(db_expr_t tid, boolean_t hastid, db_expr_t count, char *modif)
643{
644	struct thread *td;
645	db_expr_t radix;
646	pid_t pid;
647	int t;
648
649	/*
650	 * We parse our own arguments. We don't like the default radix.
651	 */
652	radix = db_radix;
653	db_radix = 10;
654	hastid = db_expression(&tid);
655	t = db_read_token();
656	if (t == tCOMMA) {
657		if (!db_expression(&count)) {
658			db_printf("Count missing\n");
659			db_flush_lex();
660			return;
661		}
662	} else {
663		db_unread_token(t);
664		count = -1;
665	}
666	db_skip_to_eol();
667	db_radix = radix;
668
669	if (hastid) {
670		td = kdb_thr_lookup((lwpid_t)tid);
671		if (td == NULL)
672			td = kdb_thr_from_pid((pid_t)tid);
673		if (td == NULL) {
674			db_printf("Thread %d not found\n", (int)tid);
675			return;
676		}
677	} else
678		td = kdb_thread;
679	if (td->td_proc != NULL)
680		pid = td->td_proc->p_pid;
681	else
682		pid = -1;
683	db_printf("Tracing pid %d tid %ld td %p\n", pid, (long)td->td_tid, td);
684	db_trace_thread(td, count);
685}
686
687static void
688db_stack_trace_all(db_expr_t dummy, boolean_t dummy2, db_expr_t dummy3,
689    char *dummy4)
690{
691	struct proc *p;
692	struct thread *td;
693
694	LIST_FOREACH(p, &allproc, p_list) {
695		FOREACH_THREAD_IN_PROC(p, td) {
696			db_printf("\nTracing command %s pid %d tid %ld td %p\n",
697			    p->p_comm, p->p_pid, (long)td->td_tid, td);
698			db_trace_thread(td, -1);
699			if (db_pager_quit)
700				return;
701		}
702	}
703}
704