db_command.c revision 150819 
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 150819 2005-10-02 11:41:12Z rwatson $");
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_kill;
72static db_cmdfcn_t	db_reset;
73static db_cmdfcn_t	db_stack_trace;
74static db_cmdfcn_t	db_stack_trace_all;
75static db_cmdfcn_t	db_watchdog;
76
77/*
78 * 'show' commands
79 */
80
81static struct command db_show_all_cmds[] = {
82	{ "procs",	db_ps,			0,	0 },
83	{ (char *)0 }
84};
85
86static struct command db_show_cmds[] = {
87	{ "all",	0,			0,	db_show_all_cmds },
88	{ "registers",	db_show_regs,		0,	0 },
89	{ "breaks",	db_listbreak_cmd, 	0,	0 },
90	{ "threads",	db_show_threads,	0,	0 },
91	{ (char *)0, }
92};
93
94static struct command db_command_table[] = {
95	{ "print",	db_print_cmd,		0,	0 },
96	{ "p",		db_print_cmd,		0,	0 },
97	{ "examine",	db_examine_cmd,		CS_SET_DOT, 0 },
98	{ "x",		db_examine_cmd,		CS_SET_DOT, 0 },
99	{ "search",	db_search_cmd,		CS_OWN|CS_SET_DOT, 0 },
100	{ "set",	db_set_cmd,		CS_OWN,	0 },
101	{ "write",	db_write_cmd,		CS_MORE|CS_SET_DOT, 0 },
102	{ "w",		db_write_cmd,		CS_MORE|CS_SET_DOT, 0 },
103	{ "delete",	db_delete_cmd,		0,	0 },
104	{ "d",		db_delete_cmd,		0,	0 },
105	{ "break",	db_breakpoint_cmd,	0,	0 },
106	{ "dwatch",	db_deletewatch_cmd,	0,	0 },
107	{ "watch",	db_watchpoint_cmd,	CS_MORE,0 },
108	{ "dhwatch",	db_deletehwatch_cmd,	0,      0 },
109	{ "hwatch",	db_hwatchpoint_cmd,	0,      0 },
110	{ "step",	db_single_step_cmd,	0,	0 },
111	{ "s",		db_single_step_cmd,	0,	0 },
112	{ "continue",	db_continue_cmd,	0,	0 },
113	{ "c",		db_continue_cmd,	0,	0 },
114	{ "until",	db_trace_until_call_cmd,0,	0 },
115	{ "next",	db_trace_until_matching_cmd,0,	0 },
116	{ "match",	db_trace_until_matching_cmd,0,	0 },
117	{ "trace",	db_stack_trace,		CS_OWN,	0 },
118	{ "traceall",	db_stack_trace_all,	0,	0 },
119	{ "where",	db_stack_trace,		CS_OWN,	0 },
120	{ "call",	db_fncall,		CS_OWN,	0 },
121	{ "show",	0,			0,	db_show_cmds },
122	{ "ps",		db_ps,			0,	0 },
123	{ "gdb",	db_gdb,			0,	0 },
124	{ "reset",	db_reset,		0,	0 },
125	{ "kill",	db_kill,		CS_OWN,	0 },
126	{ "watchdog",	db_watchdog,		0,	0 },
127	{ "thread",	db_set_thread,		CS_OWN,	0 },
128	{ (char *)0, }
129};
130
131static struct command	*db_last_command = 0;
132
133/*
134 * if 'ed' style: 'dot' is set at start of last item printed,
135 * and '+' points to next line.
136 * Otherwise: 'dot' points to next item, '..' points to last.
137 */
138static boolean_t	db_ed_style = TRUE;
139
140/*
141 * Utility routine - discard tokens through end-of-line.
142 */
143void
144db_skip_to_eol()
145{
146	int	t;
147	do {
148	    t = db_read_token();
149	} while (t != tEOL);
150}
151
152/*
153 * Results of command search.
154 */
155#define	CMD_UNIQUE	0
156#define	CMD_FOUND	1
157#define	CMD_NONE	2
158#define	CMD_AMBIGUOUS	3
159#define	CMD_HELP	4
160
161static void	db_cmd_list(struct command *table, struct command **aux_tablep,
162		    struct command **aux_tablep_end);
163static int	db_cmd_search(char *name, struct command *table,
164		    struct command **aux_tablep,
165		    struct command **aux_tablep_end, struct command **cmdp);
166static void	db_command(struct command **last_cmdp,
167		    struct command *cmd_table, struct command **aux_cmd_tablep,
168		    struct command **aux_cmd_tablep_end);
169
170/*
171 * Search for command prefix.
172 */
173static int
174db_cmd_search(name, table, aux_tablep, aux_tablep_end, cmdp)
175	char *		name;
176	struct command	*table;
177	struct command	**aux_tablep;
178	struct command	**aux_tablep_end;
179	struct command	**cmdp;	/* out */
180{
181	struct command	*cmd;
182	struct command	**aux_cmdp;
183	int		result = CMD_NONE;
184
185	for (cmd = table; cmd->name != 0; cmd++) {
186	    register char *lp;
187	    register char *rp;
188	    register int  c;
189
190	    lp = name;
191	    rp = cmd->name;
192	    while ((c = *lp) == *rp) {
193		if (c == 0) {
194		    /* complete match */
195		    *cmdp = cmd;
196		    return (CMD_UNIQUE);
197		}
198		lp++;
199		rp++;
200	    }
201	    if (c == 0) {
202		/* end of name, not end of command -
203		   partial match */
204		if (result == CMD_FOUND) {
205		    result = CMD_AMBIGUOUS;
206		    /* but keep looking for a full match -
207		       this lets us match single letters */
208		}
209		else {
210		    *cmdp = cmd;
211		    result = CMD_FOUND;
212		}
213	    }
214	}
215	if (result == CMD_NONE && aux_tablep != 0)
216	    /* XXX repeat too much code. */
217	    for (aux_cmdp = aux_tablep; aux_cmdp < aux_tablep_end; aux_cmdp++) {
218		register char *lp;
219		register char *rp;
220		register int  c;
221
222		lp = name;
223		rp = (*aux_cmdp)->name;
224		while ((c = *lp) == *rp) {
225		    if (c == 0) {
226			/* complete match */
227			*cmdp = *aux_cmdp;
228			return (CMD_UNIQUE);
229		    }
230		    lp++;
231		    rp++;
232		}
233		if (c == 0) {
234		    /* end of name, not end of command -
235		       partial match */
236		    if (result == CMD_FOUND) {
237			result = CMD_AMBIGUOUS;
238			/* but keep looking for a full match -
239			   this lets us match single letters */
240		    }
241		    else {
242			*cmdp = *aux_cmdp;
243			result = CMD_FOUND;
244		    }
245		}
246	    }
247	if (result == CMD_NONE) {
248	    /* check for 'help' */
249		if (name[0] == 'h' && name[1] == 'e'
250		    && name[2] == 'l' && name[3] == 'p')
251			result = CMD_HELP;
252	}
253	return (result);
254}
255
256static void
257db_cmd_list(table, aux_tablep, aux_tablep_end)
258	struct command *table;
259	struct command **aux_tablep;
260	struct command **aux_tablep_end;
261{
262	register struct command *cmd;
263	register struct command **aux_cmdp;
264
265	for (cmd = table; cmd->name != 0; cmd++) {
266	    db_printf("%-12s", cmd->name);
267	    db_end_line();
268	}
269	if (aux_tablep == 0)
270	    return;
271	for (aux_cmdp = aux_tablep; aux_cmdp < aux_tablep_end; aux_cmdp++) {
272	    db_printf("%-12s", (*aux_cmdp)->name);
273	    db_end_line();
274	}
275}
276
277static void
278db_command(last_cmdp, cmd_table, aux_cmd_tablep, aux_cmd_tablep_end)
279	struct command	**last_cmdp;	/* IN_OUT */
280	struct command	*cmd_table;
281	struct command	**aux_cmd_tablep;
282	struct command	**aux_cmd_tablep_end;
283{
284	struct command	*cmd;
285	int		t;
286	char		modif[TOK_STRING_SIZE];
287	db_expr_t	addr, count;
288	boolean_t	have_addr = FALSE;
289	int		result;
290
291	t = db_read_token();
292	if (t == tEOL) {
293	    /* empty line repeats last command, at 'next' */
294	    cmd = *last_cmdp;
295	    addr = (db_expr_t)db_next;
296	    have_addr = FALSE;
297	    count = 1;
298	    modif[0] = '\0';
299	}
300	else if (t == tEXCL) {
301	    db_fncall((db_expr_t)0, (boolean_t)0, (db_expr_t)0, (char *)0);
302	    return;
303	}
304	else if (t != tIDENT) {
305	    db_printf("?\n");
306	    db_flush_lex();
307	    return;
308	}
309	else {
310	    /*
311	     * Search for command
312	     */
313	    while (cmd_table) {
314		result = db_cmd_search(db_tok_string,
315				       cmd_table,
316				       aux_cmd_tablep,
317				       aux_cmd_tablep_end,
318				       &cmd);
319		switch (result) {
320		    case CMD_NONE:
321			db_printf("No such command\n");
322			db_flush_lex();
323			return;
324		    case CMD_AMBIGUOUS:
325			db_printf("Ambiguous\n");
326			db_flush_lex();
327			return;
328		    case CMD_HELP:
329			db_cmd_list(cmd_table, aux_cmd_tablep, aux_cmd_tablep_end);
330			db_flush_lex();
331			return;
332		    default:
333			break;
334		}
335		if ((cmd_table = cmd->more) != 0) {
336		    /* XXX usually no more aux's. */
337		    aux_cmd_tablep = 0;
338		    if (cmd_table == db_show_cmds) {
339			aux_cmd_tablep = SET_BEGIN(db_show_cmd_set);
340			aux_cmd_tablep_end = SET_LIMIT(db_show_cmd_set);
341		    }
342
343		    t = db_read_token();
344		    if (t != tIDENT) {
345			db_cmd_list(cmd_table, aux_cmd_tablep, aux_cmd_tablep_end);
346			db_flush_lex();
347			return;
348		    }
349		}
350	    }
351
352	    if ((cmd->flag & CS_OWN) == 0) {
353		/*
354		 * Standard syntax:
355		 * command [/modifier] [addr] [,count]
356		 */
357		t = db_read_token();
358		if (t == tSLASH) {
359		    t = db_read_token();
360		    if (t != tIDENT) {
361			db_printf("Bad modifier\n");
362			db_flush_lex();
363			return;
364		    }
365		    db_strcpy(modif, db_tok_string);
366		}
367		else {
368		    db_unread_token(t);
369		    modif[0] = '\0';
370		}
371
372		if (db_expression(&addr)) {
373		    db_dot = (db_addr_t) addr;
374		    db_last_addr = db_dot;
375		    have_addr = TRUE;
376		}
377		else {
378		    addr = (db_expr_t) db_dot;
379		    have_addr = FALSE;
380		}
381		t = db_read_token();
382		if (t == tCOMMA) {
383		    if (!db_expression(&count)) {
384			db_printf("Count missing\n");
385			db_flush_lex();
386			return;
387		    }
388		}
389		else {
390		    db_unread_token(t);
391		    count = -1;
392		}
393		if ((cmd->flag & CS_MORE) == 0) {
394		    db_skip_to_eol();
395		}
396	    }
397	}
398	*last_cmdp = cmd;
399	if (cmd != 0) {
400	    /*
401	     * Execute the command.
402	     */
403	    (*cmd->fcn)(addr, have_addr, count, modif);
404	    db_setup_paging(NULL, NULL, -1);
405
406	    if (cmd->flag & CS_SET_DOT) {
407		/*
408		 * If command changes dot, set dot to
409		 * previous address displayed (if 'ed' style).
410		 */
411		if (db_ed_style) {
412		    db_dot = db_prev;
413		}
414		else {
415		    db_dot = db_next;
416		}
417	    }
418	    else {
419		/*
420		 * If command does not change dot,
421		 * set 'next' location to be the same.
422		 */
423		db_next = db_dot;
424	    }
425	}
426}
427
428/*
429 * At least one non-optional command must be implemented using
430 * DB_COMMAND() so that db_cmd_set gets created.  Here is one.
431 */
432DB_COMMAND(panic, db_panic)
433{
434	panic("from debugger");
435}
436
437void
438db_command_loop()
439{
440	/*
441	 * Initialize 'prev' and 'next' to dot.
442	 */
443	db_prev = db_dot;
444	db_next = db_dot;
445
446	db_cmd_loop_done = 0;
447	while (!db_cmd_loop_done) {
448	    if (db_print_position() != 0)
449		db_printf("\n");
450
451	    db_printf("db> ");
452	    (void) db_read_line();
453
454	    db_command(&db_last_command, db_command_table,
455		       SET_BEGIN(db_cmd_set), SET_LIMIT(db_cmd_set));
456	}
457}
458
459void
460db_error(s)
461	const char *s;
462{
463	if (s)
464	    db_printf("%s", s);
465	db_flush_lex();
466	kdb_reenter();
467}
468
469
470/*
471 * Call random function:
472 * !expr(arg,arg,arg)
473 */
474
475/* The generic implementation supports a maximum of 10 arguments. */
476typedef db_expr_t __db_f(db_expr_t, db_expr_t, db_expr_t, db_expr_t,
477    db_expr_t, db_expr_t, db_expr_t, db_expr_t, db_expr_t, db_expr_t);
478
479static __inline int
480db_fncall_generic(db_expr_t addr, db_expr_t *rv, int nargs, db_expr_t args[])
481{
482	__db_f *f = (__db_f *)addr;
483
484	if (nargs > 10) {
485		db_printf("Too many arguments (max 10)\n");
486		return (0);
487	}
488	*rv = (*f)(args[0], args[1], args[2], args[3], args[4], args[5],
489	    args[6], args[7], args[8], args[9]);
490	return (1);
491}
492
493static void
494db_fncall(dummy1, dummy2, dummy3, dummy4)
495	db_expr_t	dummy1;
496	boolean_t	dummy2;
497	db_expr_t	dummy3;
498	char *		dummy4;
499{
500	db_expr_t	fn_addr;
501	db_expr_t	args[DB_MAXARGS];
502	int		nargs = 0;
503	db_expr_t	retval;
504	int		t;
505
506	if (!db_expression(&fn_addr)) {
507	    db_printf("Bad function\n");
508	    db_flush_lex();
509	    return;
510	}
511
512	t = db_read_token();
513	if (t == tLPAREN) {
514	    if (db_expression(&args[0])) {
515		nargs++;
516		while ((t = db_read_token()) == tCOMMA) {
517		    if (nargs == DB_MAXARGS) {
518			db_printf("Too many arguments (max %d)\n", DB_MAXARGS);
519			db_flush_lex();
520			return;
521		    }
522		    if (!db_expression(&args[nargs])) {
523			db_printf("Argument missing\n");
524			db_flush_lex();
525			return;
526		    }
527		    nargs++;
528		}
529		db_unread_token(t);
530	    }
531	    if (db_read_token() != tRPAREN) {
532		db_printf("?\n");
533		db_flush_lex();
534		return;
535	    }
536	}
537	db_skip_to_eol();
538
539	if (DB_CALL(fn_addr, &retval, nargs, args))
540		db_printf("= %#lr\n", (long)retval);
541}
542
543static void
544db_kill(dummy1, dummy2, dummy3, dummy4)
545	db_expr_t	dummy1;
546	boolean_t	dummy2;
547	db_expr_t	dummy3;
548	char *		dummy4;
549{
550	db_expr_t old_radix, pid, sig;
551	struct proc *p;
552
553#define DB_ERROR(f)	do { db_printf f; db_flush_lex(); goto out; } while (0)
554
555	/*
556	 * PIDs and signal numbers are typically represented in base
557	 * 10, so make that the default here.  It can, of course, be
558	 * overridden by specifying a prefix.
559	 */
560	old_radix = db_radix;
561	db_radix = 10;
562	/* Retrieve arguments. */
563	if (!db_expression(&sig))
564		DB_ERROR(("Missing signal number\n"));
565	if (!db_expression(&pid))
566		DB_ERROR(("Missing process ID\n"));
567	db_skip_to_eol();
568	if (sig < 0 || sig > _SIG_MAXSIG)
569		DB_ERROR(("Signal number out of range\n"));
570
571	/*
572	 * Find the process in question.  allproc_lock is not needed
573	 * since we're in DDB.
574	 */
575	/* sx_slock(&allproc_lock); */
576	LIST_FOREACH(p, &allproc, p_list)
577	    if (p->p_pid == pid)
578		    break;
579	/* sx_sunlock(&allproc_lock); */
580	if (p == NULL)
581		DB_ERROR(("Can't find process with pid %ld\n", (long) pid));
582
583	/* If it's already locked, bail; otherwise, do the deed. */
584	if (PROC_TRYLOCK(p) == 0)
585		DB_ERROR(("Can't lock process with pid %ld\n", (long) pid));
586	else {
587		psignal(p, sig);
588		PROC_UNLOCK(p);
589	}
590
591out:
592	db_radix = old_radix;
593#undef DB_ERROR
594}
595
596static void
597db_reset(dummy1, dummy2, dummy3, dummy4)
598	db_expr_t	dummy1;
599	boolean_t	dummy2;
600	db_expr_t	dummy3;
601	char *		dummy4;
602{
603
604	cpu_reset();
605}
606
607static void
608db_watchdog(dummy1, dummy2, dummy3, dummy4)
609	db_expr_t	dummy1;
610	boolean_t	dummy2;
611	db_expr_t	dummy3;
612	char *		dummy4;
613{
614	int i;
615
616	/*
617	 * XXX: It might make sense to be able to set the watchdog to a
618	 * XXX: timeout here so that failure or hang as a result of subsequent
619	 * XXX: ddb commands could be recovered by a reset.
620	 */
621
622	EVENTHANDLER_INVOKE(watchdog_list, 0, &i);
623}
624
625static void
626db_gdb(db_expr_t dummy1, boolean_t dummy2, db_expr_t dummy3, char *dummy4)
627{
628
629	if (kdb_dbbe_select("gdb") != 0)
630		db_printf("The remote GDB backend could not be selected.\n");
631	else
632		db_printf("Step to enter the remote GDB backend.\n");
633}
634
635static void
636db_stack_trace(db_expr_t tid, boolean_t hastid, db_expr_t count, char *modif)
637{
638	struct thread *td;
639	db_expr_t radix;
640	pid_t pid;
641	int t;
642
643	/*
644	 * We parse our own arguments. We don't like the default radix.
645	 */
646	radix = db_radix;
647	db_radix = 10;
648	hastid = db_expression(&tid);
649	t = db_read_token();
650	if (t == tCOMMA) {
651		if (!db_expression(&count)) {
652			db_printf("Count missing\n");
653			db_flush_lex();
654			return;
655		}
656	} else {
657		db_unread_token(t);
658		count = -1;
659	}
660	db_skip_to_eol();
661	db_radix = radix;
662
663	if (hastid) {
664		td = kdb_thr_lookup((lwpid_t)tid);
665		if (td == NULL)
666			td = kdb_thr_from_pid((pid_t)tid);
667		if (td == NULL) {
668			db_printf("Thread %d not found\n", (int)tid);
669			return;
670		}
671	} else
672		td = kdb_thread;
673	if (td->td_proc != NULL)
674		pid = td->td_proc->p_pid;
675	else
676		pid = -1;
677	db_printf("Tracing pid %d tid %ld td %p\n", pid, (long)td->td_tid, td);
678	db_trace_thread(td, count);
679}
680
681static void
682db_stack_trace_all(db_expr_t dummy, boolean_t dummy2, db_expr_t dummy3,
683    char *dummy4)
684{
685	struct proc *p;
686	struct thread *td;
687
688	for (p = LIST_FIRST(&allproc); p != NULL; p = LIST_NEXT(p, p_list)) {
689		FOREACH_THREAD_IN_PROC(p, td) {
690			db_printf("\nTracing command %s pid %d tid %ld td %p\n",
691			    p->p_comm, p->p_pid, (long)td->td_tid, td);
692			db_trace_thread(td, -1);
693		}
694	}
695}
696