db_command.c revision 163134 
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 163134 2006-10-08 18:15:08Z 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_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_table db_show_all_table = {
87	db_show_all_cmds
88};
89
90static struct command db_show_cmds[] = {
91	{ "all",	0,			0,	&db_show_all_table },
92	{ "registers",	db_show_regs,		0,	0 },
93	{ "breaks",	db_listbreak_cmd, 	0,	0 },
94	{ "threads",	db_show_threads,	0,	0 },
95	{ (char *)0, }
96};
97
98static struct command_table db_show_table = {
99	db_show_cmds,
100	SET_BEGIN(db_show_cmd_set),
101	SET_LIMIT(db_show_cmd_set)
102};
103
104static struct command db_commands[] = {
105	{ "print",	db_print_cmd,		0,	0 },
106	{ "p",		db_print_cmd,		0,	0 },
107	{ "examine",	db_examine_cmd,		CS_SET_DOT, 0 },
108	{ "x",		db_examine_cmd,		CS_SET_DOT, 0 },
109	{ "search",	db_search_cmd,		CS_OWN|CS_SET_DOT, 0 },
110	{ "set",	db_set_cmd,		CS_OWN,	0 },
111	{ "write",	db_write_cmd,		CS_MORE|CS_SET_DOT, 0 },
112	{ "w",		db_write_cmd,		CS_MORE|CS_SET_DOT, 0 },
113	{ "delete",	db_delete_cmd,		0,	0 },
114	{ "d",		db_delete_cmd,		0,	0 },
115	{ "break",	db_breakpoint_cmd,	0,	0 },
116	{ "dwatch",	db_deletewatch_cmd,	0,	0 },
117	{ "watch",	db_watchpoint_cmd,	CS_MORE,0 },
118	{ "dhwatch",	db_deletehwatch_cmd,	0,      0 },
119	{ "hwatch",	db_hwatchpoint_cmd,	0,      0 },
120	{ "step",	db_single_step_cmd,	0,	0 },
121	{ "s",		db_single_step_cmd,	0,	0 },
122	{ "continue",	db_continue_cmd,	0,	0 },
123	{ "c",		db_continue_cmd,	0,	0 },
124	{ "until",	db_trace_until_call_cmd,0,	0 },
125	{ "next",	db_trace_until_matching_cmd,0,	0 },
126	{ "match",	db_trace_until_matching_cmd,0,	0 },
127	{ "trace",	db_stack_trace,		CS_OWN,	0 },
128	{ "alltrace",	db_stack_trace_all,	0,	0 },
129	{ "where",	db_stack_trace,		CS_OWN,	0 },
130	{ "bt",		db_stack_trace,		CS_OWN,	0 },
131	{ "call",	db_fncall,		CS_OWN,	0 },
132	{ "show",	0,			0,	&db_show_table },
133	{ "ps",		db_ps,			0,	0 },
134	{ "gdb",	db_gdb,			0,	0 },
135	{ "reset",	db_reset,		0,	0 },
136	{ "kill",	db_kill,		CS_OWN,	0 },
137	{ "watchdog",	db_watchdog,		0,	0 },
138	{ "thread",	db_set_thread,		CS_OWN,	0 },
139	{ (char *)0, }
140};
141
142static struct command_table db_command_table = {
143	db_commands,
144	SET_BEGIN(db_cmd_set),
145	SET_LIMIT(db_cmd_set)
146};
147
148static struct command	*db_last_command = 0;
149
150/*
151 * if 'ed' style: 'dot' is set at start of last item printed,
152 * and '+' points to next line.
153 * Otherwise: 'dot' points to next item, '..' points to last.
154 */
155static boolean_t	db_ed_style = TRUE;
156
157/*
158 * Utility routine - discard tokens through end-of-line.
159 */
160void
161db_skip_to_eol()
162{
163	int	t;
164	do {
165	    t = db_read_token();
166	} while (t != tEOL);
167}
168
169/*
170 * Results of command search.
171 */
172#define	CMD_UNIQUE	0
173#define	CMD_FOUND	1
174#define	CMD_NONE	2
175#define	CMD_AMBIGUOUS	3
176#define	CMD_HELP	4
177
178static void	db_cmd_match(char *name, struct command *cmd,
179		    struct command **cmdp, int *resultp);
180static void	db_cmd_list(struct command_table *table);
181static int	db_cmd_search(char *name, struct command_table *table,
182		    struct command **cmdp);
183static void	db_command(struct command **last_cmdp,
184		    struct command_table *cmd_table);
185
186/*
187 * Helper function to match a single command.
188 */
189static void
190db_cmd_match(name, cmd, cmdp, resultp)
191	char *		name;
192	struct command	*cmd;
193	struct command	**cmdp;	/* out */
194	int *		resultp;
195{
196	char *lp, *rp;
197	int c;
198
199	lp = name;
200	rp = cmd->name;
201	while ((c = *lp) == *rp) {
202		if (c == 0) {
203			/* complete match */
204			*cmdp = cmd;
205			*resultp = CMD_UNIQUE;
206			return;
207		}
208		lp++;
209		rp++;
210	}
211	if (c == 0) {
212		/* end of name, not end of command -
213		   partial match */
214		if (*resultp == CMD_FOUND) {
215			*resultp = CMD_AMBIGUOUS;
216			/* but keep looking for a full match -
217			   this lets us match single letters */
218		} else {
219			*cmdp = cmd;
220			*resultp = CMD_FOUND;
221		}
222	}
223}
224
225/*
226 * Search for command prefix.
227 */
228static int
229db_cmd_search(name, table, cmdp)
230	char *		name;
231	struct command_table *table;
232	struct command	**cmdp;	/* out */
233{
234	struct command	*cmd;
235	struct command	**aux_cmdp;
236	int		result = CMD_NONE;
237
238	for (cmd = table->table; cmd->name != 0; cmd++) {
239		db_cmd_match(name, cmd, cmdp, &result);
240		if (result == CMD_UNIQUE)
241			return (CMD_UNIQUE);
242	}
243	if (table->aux_tablep != NULL)
244		for (aux_cmdp = table->aux_tablep;
245		     aux_cmdp < table->aux_tablep_end;
246		     aux_cmdp++) {
247			db_cmd_match(name, *aux_cmdp, cmdp, &result);
248			if (result == CMD_UNIQUE)
249				return (CMD_UNIQUE);
250		}
251	if (result == CMD_NONE) {
252		/* check for 'help' */
253		if (name[0] == 'h' && name[1] == 'e'
254		    && name[2] == 'l' && name[3] == 'p')
255			result = CMD_HELP;
256	}
257	return (result);
258}
259
260static void
261db_cmd_list(table)
262	struct command_table *table;
263{
264	register struct command *cmd;
265	register struct command **aux_cmdp;
266
267	for (cmd = table->table; cmd->name != 0; cmd++) {
268	    db_printf("%-12s", cmd->name);
269	    db_end_line(12);
270	}
271	if (table->aux_tablep == NULL)
272	    return;
273	for (aux_cmdp = table->aux_tablep; aux_cmdp < table->aux_tablep_end;
274	     aux_cmdp++) {
275	    db_printf("%-12s", (*aux_cmdp)->name);
276	    db_end_line(12);
277	}
278}
279
280static void
281db_command(last_cmdp, cmd_table)
282	struct command	**last_cmdp;	/* IN_OUT */
283	struct command_table *cmd_table;
284{
285	struct command	*cmd;
286	int		t;
287	char		modif[TOK_STRING_SIZE];
288	db_expr_t	addr, count;
289	boolean_t	have_addr = FALSE;
290	int		result;
291
292	t = db_read_token();
293	if (t == tEOL) {
294	    /* empty line repeats last command, at 'next' */
295	    cmd = *last_cmdp;
296	    addr = (db_expr_t)db_next;
297	    have_addr = FALSE;
298	    count = 1;
299	    modif[0] = '\0';
300	}
301	else if (t == tEXCL) {
302	    db_fncall((db_expr_t)0, (boolean_t)0, (db_expr_t)0, (char *)0);
303	    return;
304	}
305	else if (t != tIDENT) {
306	    db_printf("?\n");
307	    db_flush_lex();
308	    return;
309	}
310	else {
311	    /*
312	     * Search for command
313	     */
314	    while (cmd_table) {
315		result = db_cmd_search(db_tok_string,
316				       cmd_table,
317				       &cmd);
318		switch (result) {
319		    case CMD_NONE:
320			db_printf("No such command\n");
321			db_flush_lex();
322			return;
323		    case CMD_AMBIGUOUS:
324			db_printf("Ambiguous\n");
325			db_flush_lex();
326			return;
327		    case CMD_HELP:
328			db_cmd_list(cmd_table);
329			db_flush_lex();
330			return;
331		    default:
332			break;
333		}
334		if ((cmd_table = cmd->more) != NULL) {
335		    t = db_read_token();
336		    if (t != tIDENT) {
337			db_cmd_list(cmd_table);
338			db_flush_lex();
339			return;
340		    }
341		}
342	    }
343
344	    if ((cmd->flag & CS_OWN) == 0) {
345		/*
346		 * Standard syntax:
347		 * command [/modifier] [addr] [,count]
348		 */
349		t = db_read_token();
350		if (t == tSLASH) {
351		    t = db_read_token();
352		    if (t != tIDENT) {
353			db_printf("Bad modifier\n");
354			db_flush_lex();
355			return;
356		    }
357		    db_strcpy(modif, db_tok_string);
358		}
359		else {
360		    db_unread_token(t);
361		    modif[0] = '\0';
362		}
363
364		if (db_expression(&addr)) {
365		    db_dot = (db_addr_t) addr;
366		    db_last_addr = db_dot;
367		    have_addr = TRUE;
368		}
369		else {
370		    addr = (db_expr_t) db_dot;
371		    have_addr = FALSE;
372		}
373		t = db_read_token();
374		if (t == tCOMMA) {
375		    if (!db_expression(&count)) {
376			db_printf("Count missing\n");
377			db_flush_lex();
378			return;
379		    }
380		}
381		else {
382		    db_unread_token(t);
383		    count = -1;
384		}
385		if ((cmd->flag & CS_MORE) == 0) {
386		    db_skip_to_eol();
387		}
388	    }
389	}
390	*last_cmdp = cmd;
391	if (cmd != 0) {
392	    /*
393	     * Execute the command.
394	     */
395	    db_enable_pager();
396	    (*cmd->fcn)(addr, have_addr, count, modif);
397	    db_disable_pager();
398
399	    if (cmd->flag & CS_SET_DOT) {
400		/*
401		 * If command changes dot, set dot to
402		 * previous address displayed (if 'ed' style).
403		 */
404		if (db_ed_style) {
405		    db_dot = db_prev;
406		}
407		else {
408		    db_dot = db_next;
409		}
410	    }
411	    else {
412		/*
413		 * If command does not change dot,
414		 * set 'next' location to be the same.
415		 */
416		db_next = db_dot;
417	    }
418	}
419}
420
421/*
422 * At least one non-optional command must be implemented using
423 * DB_COMMAND() so that db_cmd_set gets created.  Here is one.
424 */
425DB_COMMAND(panic, db_panic)
426{
427	db_disable_pager();
428	panic("from debugger");
429}
430
431void
432db_command_loop()
433{
434	/*
435	 * Initialize 'prev' and 'next' to dot.
436	 */
437	db_prev = db_dot;
438	db_next = db_dot;
439
440	db_cmd_loop_done = 0;
441	while (!db_cmd_loop_done) {
442	    if (db_print_position() != 0)
443		db_printf("\n");
444
445	    db_printf("db> ");
446	    (void) db_read_line();
447
448	    db_command(&db_last_command, &db_command_table);
449	}
450}
451
452void
453db_error(s)
454	const char *s;
455{
456	if (s)
457	    db_printf("%s", s);
458	db_flush_lex();
459	kdb_reenter();
460}
461
462
463/*
464 * Call random function:
465 * !expr(arg,arg,arg)
466 */
467
468/* The generic implementation supports a maximum of 10 arguments. */
469typedef db_expr_t __db_f(db_expr_t, db_expr_t, db_expr_t, db_expr_t,
470    db_expr_t, db_expr_t, db_expr_t, db_expr_t, db_expr_t, db_expr_t);
471
472static __inline int
473db_fncall_generic(db_expr_t addr, db_expr_t *rv, int nargs, db_expr_t args[])
474{
475	__db_f *f = (__db_f *)addr;
476
477	if (nargs > 10) {
478		db_printf("Too many arguments (max 10)\n");
479		return (0);
480	}
481	*rv = (*f)(args[0], args[1], args[2], args[3], args[4], args[5],
482	    args[6], args[7], args[8], args[9]);
483	return (1);
484}
485
486static void
487db_fncall(dummy1, dummy2, dummy3, dummy4)
488	db_expr_t	dummy1;
489	boolean_t	dummy2;
490	db_expr_t	dummy3;
491	char *		dummy4;
492{
493	db_expr_t	fn_addr;
494	db_expr_t	args[DB_MAXARGS];
495	int		nargs = 0;
496	db_expr_t	retval;
497	int		t;
498
499	if (!db_expression(&fn_addr)) {
500	    db_printf("Bad function\n");
501	    db_flush_lex();
502	    return;
503	}
504
505	t = db_read_token();
506	if (t == tLPAREN) {
507	    if (db_expression(&args[0])) {
508		nargs++;
509		while ((t = db_read_token()) == tCOMMA) {
510		    if (nargs == DB_MAXARGS) {
511			db_printf("Too many arguments (max %d)\n", DB_MAXARGS);
512			db_flush_lex();
513			return;
514		    }
515		    if (!db_expression(&args[nargs])) {
516			db_printf("Argument missing\n");
517			db_flush_lex();
518			return;
519		    }
520		    nargs++;
521		}
522		db_unread_token(t);
523	    }
524	    if (db_read_token() != tRPAREN) {
525		db_printf("?\n");
526		db_flush_lex();
527		return;
528	    }
529	}
530	db_skip_to_eol();
531	db_disable_pager();
532
533	if (DB_CALL(fn_addr, &retval, nargs, args))
534		db_printf("= %#lr\n", (long)retval);
535}
536
537static void
538db_kill(dummy1, dummy2, dummy3, dummy4)
539	db_expr_t	dummy1;
540	boolean_t	dummy2;
541	db_expr_t	dummy3;
542	char *		dummy4;
543{
544	db_expr_t old_radix, pid, sig;
545	struct proc *p;
546
547#define DB_ERROR(f)	do { db_printf f; db_flush_lex(); goto out; } while (0)
548
549	/*
550	 * PIDs and signal numbers are typically represented in base
551	 * 10, so make that the default here.  It can, of course, be
552	 * overridden by specifying a prefix.
553	 */
554	old_radix = db_radix;
555	db_radix = 10;
556	/* Retrieve arguments. */
557	if (!db_expression(&sig))
558		DB_ERROR(("Missing signal number\n"));
559	if (!db_expression(&pid))
560		DB_ERROR(("Missing process ID\n"));
561	db_skip_to_eol();
562	if (sig < 0 || sig > _SIG_MAXSIG)
563		DB_ERROR(("Signal number out of range\n"));
564
565	/*
566	 * Find the process in question.  allproc_lock is not needed
567	 * since we're in DDB.
568	 */
569	/* sx_slock(&allproc_lock); */
570	LIST_FOREACH(p, &allproc, p_list)
571	    if (p->p_pid == pid)
572		    break;
573	/* sx_sunlock(&allproc_lock); */
574	if (p == NULL)
575		DB_ERROR(("Can't find process with pid %ld\n", (long) pid));
576
577	/* If it's already locked, bail; otherwise, do the deed. */
578	if (PROC_TRYLOCK(p) == 0)
579		DB_ERROR(("Can't lock process with pid %ld\n", (long) pid));
580	else {
581		psignal(p, sig);
582		PROC_UNLOCK(p);
583	}
584
585out:
586	db_radix = old_radix;
587#undef DB_ERROR
588}
589
590static void
591db_reset(dummy1, dummy2, dummy3, dummy4)
592	db_expr_t	dummy1;
593	boolean_t	dummy2;
594	db_expr_t	dummy3;
595	char *		dummy4;
596{
597
598	cpu_reset();
599}
600
601static void
602db_watchdog(dummy1, dummy2, dummy3, dummy4)
603	db_expr_t	dummy1;
604	boolean_t	dummy2;
605	db_expr_t	dummy3;
606	char *		dummy4;
607{
608	int i;
609
610	/*
611	 * XXX: It might make sense to be able to set the watchdog to a
612	 * XXX: timeout here so that failure or hang as a result of subsequent
613	 * XXX: ddb commands could be recovered by a reset.
614	 */
615
616	EVENTHANDLER_INVOKE(watchdog_list, 0, &i);
617}
618
619static void
620db_gdb(db_expr_t dummy1, boolean_t dummy2, db_expr_t dummy3, char *dummy4)
621{
622
623	if (kdb_dbbe_select("gdb") != 0)
624		db_printf("The remote GDB backend could not be selected.\n");
625	else
626		db_printf("Step to enter the remote GDB backend.\n");
627}
628
629static void
630db_stack_trace(db_expr_t tid, boolean_t hastid, db_expr_t count, char *modif)
631{
632	struct thread *td;
633	db_expr_t radix;
634	pid_t pid;
635	int t;
636
637	/*
638	 * We parse our own arguments. We don't like the default radix.
639	 */
640	radix = db_radix;
641	db_radix = 10;
642	hastid = db_expression(&tid);
643	t = db_read_token();
644	if (t == tCOMMA) {
645		if (!db_expression(&count)) {
646			db_printf("Count missing\n");
647			db_flush_lex();
648			return;
649		}
650	} else {
651		db_unread_token(t);
652		count = -1;
653	}
654	db_skip_to_eol();
655	db_radix = radix;
656
657	if (hastid) {
658		td = kdb_thr_lookup((lwpid_t)tid);
659		if (td == NULL)
660			td = kdb_thr_from_pid((pid_t)tid);
661		if (td == NULL) {
662			db_printf("Thread %d not found\n", (int)tid);
663			return;
664		}
665	} else
666		td = kdb_thread;
667	if (td->td_proc != NULL)
668		pid = td->td_proc->p_pid;
669	else
670		pid = -1;
671	db_printf("Tracing pid %d tid %ld td %p\n", pid, (long)td->td_tid, td);
672	db_trace_thread(td, count);
673}
674
675static void
676db_stack_trace_all(db_expr_t dummy, boolean_t dummy2, db_expr_t dummy3,
677    char *dummy4)
678{
679	struct proc *p;
680	struct thread *td;
681
682	LIST_FOREACH(p, &allproc, p_list) {
683		FOREACH_THREAD_IN_PROC(p, td) {
684			db_printf("\nTracing command %s pid %d tid %ld td %p\n",
685			    p->p_comm, p->p_pid, (long)td->td_tid, td);
686			db_trace_thread(td, -1);
687			if (db_pager_quit)
688				return;
689		}
690	}
691}
692