db_command.c revision 174910 
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 174910 2007-12-25 23:06:51Z 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_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	{ "capture",	db_capture_cmd,		CS_OWN,	0 },
145	{ (char *)0, }
146};
147
148static struct command_table db_command_table = {
149	db_commands,
150	SET_BEGIN(db_cmd_set),
151	SET_LIMIT(db_cmd_set)
152};
153
154static struct command	*db_last_command = 0;
155
156/*
157 * if 'ed' style: 'dot' is set at start of last item printed,
158 * and '+' points to next line.
159 * Otherwise: 'dot' points to next item, '..' points to last.
160 */
161static boolean_t	db_ed_style = TRUE;
162
163/*
164 * Utility routine - discard tokens through end-of-line.
165 */
166void
167db_skip_to_eol()
168{
169	int	t;
170	do {
171	    t = db_read_token();
172	} while (t != tEOL);
173}
174
175/*
176 * Results of command search.
177 */
178#define	CMD_UNIQUE	0
179#define	CMD_FOUND	1
180#define	CMD_NONE	2
181#define	CMD_AMBIGUOUS	3
182#define	CMD_HELP	4
183
184static void	db_cmd_match(char *name, struct command *cmd,
185		    struct command **cmdp, int *resultp);
186static void	db_cmd_list(struct command_table *table);
187static int	db_cmd_search(char *name, struct command_table *table,
188		    struct command **cmdp);
189static void	db_command(struct command **last_cmdp,
190		    struct command_table *cmd_table);
191
192/*
193 * Helper function to match a single command.
194 */
195static void
196db_cmd_match(name, cmd, cmdp, resultp)
197	char *		name;
198	struct command	*cmd;
199	struct command	**cmdp;	/* out */
200	int *		resultp;
201{
202	char *lp, *rp;
203	int c;
204
205	lp = name;
206	rp = cmd->name;
207	while ((c = *lp) == *rp) {
208		if (c == 0) {
209			/* complete match */
210			*cmdp = cmd;
211			*resultp = CMD_UNIQUE;
212			return;
213		}
214		lp++;
215		rp++;
216	}
217	if (c == 0) {
218		/* end of name, not end of command -
219		   partial match */
220		if (*resultp == CMD_FOUND) {
221			*resultp = CMD_AMBIGUOUS;
222			/* but keep looking for a full match -
223			   this lets us match single letters */
224		} else {
225			*cmdp = cmd;
226			*resultp = CMD_FOUND;
227		}
228	}
229}
230
231/*
232 * Search for command prefix.
233 */
234static int
235db_cmd_search(name, table, cmdp)
236	char *		name;
237	struct command_table *table;
238	struct command	**cmdp;	/* out */
239{
240	struct command	*cmd;
241	struct command	**aux_cmdp;
242	int		result = CMD_NONE;
243
244	for (cmd = table->table; cmd->name != 0; cmd++) {
245		db_cmd_match(name, cmd, cmdp, &result);
246		if (result == CMD_UNIQUE)
247			return (CMD_UNIQUE);
248	}
249	if (table->aux_tablep != NULL)
250		for (aux_cmdp = table->aux_tablep;
251		     aux_cmdp < table->aux_tablep_end;
252		     aux_cmdp++) {
253			db_cmd_match(name, *aux_cmdp, cmdp, &result);
254			if (result == CMD_UNIQUE)
255				return (CMD_UNIQUE);
256		}
257	if (result == CMD_NONE) {
258		/* check for 'help' */
259		if (name[0] == 'h' && name[1] == 'e'
260		    && name[2] == 'l' && name[3] == 'p')
261			result = CMD_HELP;
262	}
263	return (result);
264}
265
266static void
267db_cmd_list(table)
268	struct command_table *table;
269{
270	register struct command *cmd;
271	register struct command **aux_cmdp;
272
273	for (cmd = table->table; cmd->name != 0; cmd++) {
274	    db_printf("%-12s", cmd->name);
275	    db_end_line(12);
276	}
277	if (table->aux_tablep == NULL)
278	    return;
279	for (aux_cmdp = table->aux_tablep; aux_cmdp < table->aux_tablep_end;
280	     aux_cmdp++) {
281	    db_printf("%-12s", (*aux_cmdp)->name);
282	    db_end_line(12);
283	}
284}
285
286static void
287db_command(last_cmdp, cmd_table)
288	struct command	**last_cmdp;	/* IN_OUT */
289	struct command_table *cmd_table;
290{
291	struct command	*cmd;
292	int		t;
293	char		modif[TOK_STRING_SIZE];
294	db_expr_t	addr, count;
295	boolean_t	have_addr = FALSE;
296	int		result;
297
298	t = db_read_token();
299	if (t == tEOL) {
300	    /* empty line repeats last command, at 'next' */
301	    cmd = *last_cmdp;
302	    addr = (db_expr_t)db_next;
303	    have_addr = FALSE;
304	    count = 1;
305	    modif[0] = '\0';
306	}
307	else if (t == tEXCL) {
308	    db_fncall((db_expr_t)0, (boolean_t)0, (db_expr_t)0, (char *)0);
309	    return;
310	}
311	else if (t != tIDENT) {
312	    db_printf("?\n");
313	    db_flush_lex();
314	    return;
315	}
316	else {
317	    /*
318	     * Search for command
319	     */
320	    while (cmd_table) {
321		result = db_cmd_search(db_tok_string,
322				       cmd_table,
323				       &cmd);
324		switch (result) {
325		    case CMD_NONE:
326			db_printf("No such command\n");
327			db_flush_lex();
328			return;
329		    case CMD_AMBIGUOUS:
330			db_printf("Ambiguous\n");
331			db_flush_lex();
332			return;
333		    case CMD_HELP:
334			db_cmd_list(cmd_table);
335			db_flush_lex();
336			return;
337		    default:
338			break;
339		}
340		if ((cmd_table = cmd->more) != NULL) {
341		    t = db_read_token();
342		    if (t != tIDENT) {
343			db_cmd_list(cmd_table);
344			db_flush_lex();
345			return;
346		    }
347		}
348	    }
349
350	    if ((cmd->flag & CS_OWN) == 0) {
351		/*
352		 * Standard syntax:
353		 * command [/modifier] [addr] [,count]
354		 */
355		t = db_read_token();
356		if (t == tSLASH) {
357		    t = db_read_token();
358		    if (t != tIDENT) {
359			db_printf("Bad modifier\n");
360			db_flush_lex();
361			return;
362		    }
363		    db_strcpy(modif, db_tok_string);
364		}
365		else {
366		    db_unread_token(t);
367		    modif[0] = '\0';
368		}
369
370		if (db_expression(&addr)) {
371		    db_dot = (db_addr_t) addr;
372		    db_last_addr = db_dot;
373		    have_addr = TRUE;
374		}
375		else {
376		    addr = (db_expr_t) db_dot;
377		    have_addr = FALSE;
378		}
379		t = db_read_token();
380		if (t == tCOMMA) {
381		    if (!db_expression(&count)) {
382			db_printf("Count missing\n");
383			db_flush_lex();
384			return;
385		    }
386		}
387		else {
388		    db_unread_token(t);
389		    count = -1;
390		}
391		if ((cmd->flag & CS_MORE) == 0) {
392		    db_skip_to_eol();
393		}
394	    }
395	}
396	*last_cmdp = cmd;
397	if (cmd != 0) {
398	    /*
399	     * Execute the command.
400	     */
401	    db_enable_pager();
402	    (*cmd->fcn)(addr, have_addr, count, modif);
403	    db_disable_pager();
404
405	    if (cmd->flag & CS_SET_DOT) {
406		/*
407		 * If command changes dot, set dot to
408		 * previous address displayed (if 'ed' style).
409		 */
410		if (db_ed_style) {
411		    db_dot = db_prev;
412		}
413		else {
414		    db_dot = db_next;
415		}
416	    }
417	    else {
418		/*
419		 * If command does not change dot,
420		 * set 'next' location to be the same.
421		 */
422		db_next = db_dot;
423	    }
424	}
425}
426
427/*
428 * At least one non-optional command must be implemented using
429 * DB_COMMAND() so that db_cmd_set gets created.  Here is one.
430 */
431DB_COMMAND(panic, db_panic)
432{
433	db_disable_pager();
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	}
456}
457
458void
459db_error(s)
460	const char *s;
461{
462	if (s)
463	    db_printf("%s", s);
464	db_flush_lex();
465	kdb_reenter();
466}
467
468
469/*
470 * Call random function:
471 * !expr(arg,arg,arg)
472 */
473
474/* The generic implementation supports a maximum of 10 arguments. */
475typedef db_expr_t __db_f(db_expr_t, db_expr_t, db_expr_t, db_expr_t,
476    db_expr_t, db_expr_t, db_expr_t, db_expr_t, db_expr_t, db_expr_t);
477
478static __inline int
479db_fncall_generic(db_expr_t addr, db_expr_t *rv, int nargs, db_expr_t args[])
480{
481	__db_f *f = (__db_f *)addr;
482
483	if (nargs > 10) {
484		db_printf("Too many arguments (max 10)\n");
485		return (0);
486	}
487	*rv = (*f)(args[0], args[1], args[2], args[3], args[4], args[5],
488	    args[6], args[7], args[8], args[9]);
489	return (1);
490}
491
492static void
493db_fncall(dummy1, dummy2, dummy3, dummy4)
494	db_expr_t	dummy1;
495	boolean_t	dummy2;
496	db_expr_t	dummy3;
497	char *		dummy4;
498{
499	db_expr_t	fn_addr;
500	db_expr_t	args[DB_MAXARGS];
501	int		nargs = 0;
502	db_expr_t	retval;
503	int		t;
504
505	if (!db_expression(&fn_addr)) {
506	    db_printf("Bad function\n");
507	    db_flush_lex();
508	    return;
509	}
510
511	t = db_read_token();
512	if (t == tLPAREN) {
513	    if (db_expression(&args[0])) {
514		nargs++;
515		while ((t = db_read_token()) == tCOMMA) {
516		    if (nargs == DB_MAXARGS) {
517			db_printf("Too many arguments (max %d)\n", DB_MAXARGS);
518			db_flush_lex();
519			return;
520		    }
521		    if (!db_expression(&args[nargs])) {
522			db_printf("Argument missing\n");
523			db_flush_lex();
524			return;
525		    }
526		    nargs++;
527		}
528		db_unread_token(t);
529	    }
530	    if (db_read_token() != tRPAREN) {
531		db_printf("?\n");
532		db_flush_lex();
533		return;
534	    }
535	}
536	db_skip_to_eol();
537	db_disable_pager();
538
539	if (DB_CALL(fn_addr, &retval, nargs, args))
540		db_printf("= %#lr\n", (long)retval);
541}
542
543static void
544db_halt(db_expr_t dummy, boolean_t dummy2, db_expr_t dummy3, char *dummy4)
545{
546
547	cpu_halt();
548}
549
550static void
551db_kill(dummy1, dummy2, dummy3, dummy4)
552	db_expr_t	dummy1;
553	boolean_t	dummy2;
554	db_expr_t	dummy3;
555	char *		dummy4;
556{
557	db_expr_t old_radix, pid, sig;
558	struct proc *p;
559
560#define DB_ERROR(f)	do { db_printf f; db_flush_lex(); goto out; } while (0)
561
562	/*
563	 * PIDs and signal numbers are typically represented in base
564	 * 10, so make that the default here.  It can, of course, be
565	 * overridden by specifying a prefix.
566	 */
567	old_radix = db_radix;
568	db_radix = 10;
569	/* Retrieve arguments. */
570	if (!db_expression(&sig))
571		DB_ERROR(("Missing signal number\n"));
572	if (!db_expression(&pid))
573		DB_ERROR(("Missing process ID\n"));
574	db_skip_to_eol();
575	if (sig < 0 || sig > _SIG_MAXSIG)
576		DB_ERROR(("Signal number out of range\n"));
577
578	/*
579	 * Find the process in question.  allproc_lock is not needed
580	 * since we're in DDB.
581	 */
582	/* sx_slock(&allproc_lock); */
583	FOREACH_PROC_IN_SYSTEM(p)
584	    if (p->p_pid == pid)
585		    break;
586	/* sx_sunlock(&allproc_lock); */
587	if (p == NULL)
588		DB_ERROR(("Can't find process with pid %ld\n", (long) pid));
589
590	/* If it's already locked, bail; otherwise, do the deed. */
591	if (PROC_TRYLOCK(p) == 0)
592		DB_ERROR(("Can't lock process with pid %ld\n", (long) pid));
593	else {
594		psignal(p, sig);
595		PROC_UNLOCK(p);
596	}
597
598out:
599	db_radix = old_radix;
600#undef DB_ERROR
601}
602
603static void
604db_reset(dummy1, dummy2, dummy3, dummy4)
605	db_expr_t	dummy1;
606	boolean_t	dummy2;
607	db_expr_t	dummy3;
608	char *		dummy4;
609{
610
611	cpu_reset();
612}
613
614static void
615db_watchdog(dummy1, dummy2, dummy3, dummy4)
616	db_expr_t	dummy1;
617	boolean_t	dummy2;
618	db_expr_t	dummy3;
619	char *		dummy4;
620{
621	int i;
622
623	/*
624	 * XXX: It might make sense to be able to set the watchdog to a
625	 * XXX: timeout here so that failure or hang as a result of subsequent
626	 * XXX: ddb commands could be recovered by a reset.
627	 */
628
629	EVENTHANDLER_INVOKE(watchdog_list, 0, &i);
630}
631
632static void
633db_gdb(db_expr_t dummy1, boolean_t dummy2, db_expr_t dummy3, char *dummy4)
634{
635
636	if (kdb_dbbe_select("gdb") != 0)
637		db_printf("The remote GDB backend could not be selected.\n");
638	else
639		db_printf("Step to enter the remote GDB backend.\n");
640}
641
642static void
643db_stack_trace(db_expr_t tid, boolean_t hastid, db_expr_t count, char *modif)
644{
645	struct thread *td;
646	db_expr_t radix;
647	pid_t pid;
648	int t;
649
650	/*
651	 * We parse our own arguments. We don't like the default radix.
652	 */
653	radix = db_radix;
654	db_radix = 10;
655	hastid = db_expression(&tid);
656	t = db_read_token();
657	if (t == tCOMMA) {
658		if (!db_expression(&count)) {
659			db_printf("Count missing\n");
660			db_flush_lex();
661			return;
662		}
663	} else {
664		db_unread_token(t);
665		count = -1;
666	}
667	db_skip_to_eol();
668	db_radix = radix;
669
670	if (hastid) {
671		td = kdb_thr_lookup((lwpid_t)tid);
672		if (td == NULL)
673			td = kdb_thr_from_pid((pid_t)tid);
674		if (td == NULL) {
675			db_printf("Thread %d not found\n", (int)tid);
676			return;
677		}
678	} else
679		td = kdb_thread;
680	if (td->td_proc != NULL)
681		pid = td->td_proc->p_pid;
682	else
683		pid = -1;
684	db_printf("Tracing pid %d tid %ld td %p\n", pid, (long)td->td_tid, td);
685	db_trace_thread(td, count);
686}
687
688static void
689db_stack_trace_all(db_expr_t dummy, boolean_t dummy2, db_expr_t dummy3,
690    char *dummy4)
691{
692	struct proc *p;
693	struct thread *td;
694	jmp_buf jb;
695	void *prev_jb;
696
697	FOREACH_PROC_IN_SYSTEM(p) {
698		prev_jb = kdb_jmpbuf(jb);
699		if (setjmp(jb) == 0) {
700			FOREACH_THREAD_IN_PROC(p, td) {
701				db_printf("\nTracing command %s pid %d tid %ld td %p\n",
702					  p->p_comm, p->p_pid, (long)td->td_tid, td);
703				db_trace_thread(td, -1);
704				if (db_pager_quit) {
705					kdb_jmpbuf(prev_jb);
706					return;
707				}
708			}
709		}
710		kdb_jmpbuf(prev_jb);
711	}
712}
713