db_command.c revision 177615 
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 177615 2008-03-25 20:36:32Z sam $");
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);
68SET_DECLARE(db_show_all_cmd_set, struct command);
69
70static db_cmdfcn_t	db_fncall;
71static db_cmdfcn_t	db_gdb;
72static db_cmdfcn_t	db_halt;
73static db_cmdfcn_t	db_kill;
74static db_cmdfcn_t	db_reset;
75static db_cmdfcn_t	db_stack_trace;
76static db_cmdfcn_t	db_stack_trace_all;
77static db_cmdfcn_t	db_watchdog;
78
79/*
80 * 'show' commands
81 */
82
83static struct command db_show_all_cmds[] = {
84	{ (char *)0 }
85};
86
87static struct command_table db_show_all_table = {
88	db_show_all_cmds,
89	SET_BEGIN(db_show_all_cmd_set),
90	SET_LIMIT(db_show_all_cmd_set)
91};
92
93static struct command db_show_cmds[] = {
94	{ "all",	0,			0,	&db_show_all_table },
95	{ "registers",	db_show_regs,		0,	0 },
96	{ "breaks",	db_listbreak_cmd, 	0,	0 },
97	{ "threads",	db_show_threads,	0,	0 },
98	{ (char *)0, }
99};
100
101static struct command_table db_show_table = {
102	db_show_cmds,
103	SET_BEGIN(db_show_cmd_set),
104	SET_LIMIT(db_show_cmd_set)
105};
106
107static struct command db_commands[] = {
108	{ "print",	db_print_cmd,		0,	0 },
109	{ "p",		db_print_cmd,		0,	0 },
110	{ "examine",	db_examine_cmd,		CS_SET_DOT, 0 },
111	{ "x",		db_examine_cmd,		CS_SET_DOT, 0 },
112	{ "search",	db_search_cmd,		CS_OWN|CS_SET_DOT, 0 },
113	{ "set",	db_set_cmd,		CS_OWN,	0 },
114	{ "write",	db_write_cmd,		CS_MORE|CS_SET_DOT, 0 },
115	{ "w",		db_write_cmd,		CS_MORE|CS_SET_DOT, 0 },
116	{ "delete",	db_delete_cmd,		0,	0 },
117	{ "d",		db_delete_cmd,		0,	0 },
118	{ "break",	db_breakpoint_cmd,	0,	0 },
119	{ "b",		db_breakpoint_cmd,	0,	0 },
120	{ "dwatch",	db_deletewatch_cmd,	0,	0 },
121	{ "watch",	db_watchpoint_cmd,	CS_MORE,0 },
122	{ "dhwatch",	db_deletehwatch_cmd,	0,      0 },
123	{ "hwatch",	db_hwatchpoint_cmd,	0,      0 },
124	{ "step",	db_single_step_cmd,	0,	0 },
125	{ "s",		db_single_step_cmd,	0,	0 },
126	{ "continue",	db_continue_cmd,	0,	0 },
127	{ "c",		db_continue_cmd,	0,	0 },
128	{ "until",	db_trace_until_call_cmd,0,	0 },
129	{ "next",	db_trace_until_matching_cmd,0,	0 },
130	{ "match",	db_trace_until_matching_cmd,0,	0 },
131	{ "trace",	db_stack_trace,		CS_OWN,	0 },
132	{ "t",		db_stack_trace,		CS_OWN,	0 },
133	{ "alltrace",	db_stack_trace_all,	0,	0 },
134	{ "where",	db_stack_trace,		CS_OWN,	0 },
135	{ "bt",		db_stack_trace,		CS_OWN,	0 },
136	{ "call",	db_fncall,		CS_OWN,	0 },
137	{ "show",	0,			0,	&db_show_table },
138	{ "ps",		db_ps,			0,	0 },
139	{ "gdb",	db_gdb,			0,	0 },
140	{ "halt",	db_halt,		0,	0 },
141	{ "reboot",	db_reset,		0,	0 },
142	{ "reset",	db_reset,		0,	0 },
143	{ "kill",	db_kill,		CS_OWN,	0 },
144	{ "watchdog",	db_watchdog,		0,	0 },
145	{ "thread",	db_set_thread,		CS_OWN,	0 },
146	{ "run",	db_run_cmd,		CS_OWN,	0 },
147	{ "script",	db_script_cmd,		CS_OWN,	0 },
148	{ "scripts",	db_scripts_cmd,		0,	0 },
149	{ "unscript",	db_unscript_cmd,	CS_OWN,	0 },
150	{ "capture",	db_capture_cmd,		CS_OWN,	0 },
151	{ "textdump",	db_textdump_cmd,	CS_OWN, 0 },
152	{ (char *)0, }
153};
154
155static struct command_table db_command_table = {
156	db_commands,
157	SET_BEGIN(db_cmd_set),
158	SET_LIMIT(db_cmd_set)
159};
160
161static struct command	*db_last_command = 0;
162
163/*
164 * if 'ed' style: 'dot' is set at start of last item printed,
165 * and '+' points to next line.
166 * Otherwise: 'dot' points to next item, '..' points to last.
167 */
168static boolean_t	db_ed_style = TRUE;
169
170/*
171 * Utility routine - discard tokens through end-of-line.
172 */
173void
174db_skip_to_eol()
175{
176	int	t;
177	do {
178	    t = db_read_token();
179	} while (t != tEOL);
180}
181
182/*
183 * Results of command search.
184 */
185#define	CMD_UNIQUE	0
186#define	CMD_FOUND	1
187#define	CMD_NONE	2
188#define	CMD_AMBIGUOUS	3
189#define	CMD_HELP	4
190
191static void	db_cmd_match(char *name, struct command *cmd,
192		    struct command **cmdp, int *resultp);
193static void	db_cmd_list(struct command_table *table);
194static int	db_cmd_search(char *name, struct command_table *table,
195		    struct command **cmdp);
196static void	db_command(struct command **last_cmdp,
197		    struct command_table *cmd_table, int dopager);
198
199/*
200 * Helper function to match a single command.
201 */
202static void
203db_cmd_match(name, cmd, cmdp, resultp)
204	char *		name;
205	struct command	*cmd;
206	struct command	**cmdp;	/* out */
207	int *		resultp;
208{
209	char *lp, *rp;
210	int c;
211
212	lp = name;
213	rp = cmd->name;
214	while ((c = *lp) == *rp) {
215		if (c == 0) {
216			/* complete match */
217			*cmdp = cmd;
218			*resultp = CMD_UNIQUE;
219			return;
220		}
221		lp++;
222		rp++;
223	}
224	if (c == 0) {
225		/* end of name, not end of command -
226		   partial match */
227		if (*resultp == CMD_FOUND) {
228			*resultp = CMD_AMBIGUOUS;
229			/* but keep looking for a full match -
230			   this lets us match single letters */
231		} else {
232			*cmdp = cmd;
233			*resultp = CMD_FOUND;
234		}
235	}
236}
237
238/*
239 * Search for command prefix.
240 */
241static int
242db_cmd_search(name, table, cmdp)
243	char *		name;
244	struct command_table *table;
245	struct command	**cmdp;	/* out */
246{
247	struct command	*cmd;
248	struct command	**aux_cmdp;
249	int		result = CMD_NONE;
250
251	for (cmd = table->table; cmd->name != 0; cmd++) {
252		db_cmd_match(name, cmd, cmdp, &result);
253		if (result == CMD_UNIQUE)
254			return (CMD_UNIQUE);
255	}
256	if (table->aux_tablep != NULL)
257		for (aux_cmdp = table->aux_tablep;
258		     aux_cmdp < table->aux_tablep_end;
259		     aux_cmdp++) {
260			db_cmd_match(name, *aux_cmdp, cmdp, &result);
261			if (result == CMD_UNIQUE)
262				return (CMD_UNIQUE);
263		}
264	if (result == CMD_NONE) {
265		/* check for 'help' */
266		if (name[0] == 'h' && name[1] == 'e'
267		    && name[2] == 'l' && name[3] == 'p')
268			result = CMD_HELP;
269	}
270	return (result);
271}
272
273static void
274db_cmd_list(table)
275	struct command_table *table;
276{
277	register struct command *cmd;
278	register struct command **aux_cmdp;
279
280	for (cmd = table->table; cmd->name != 0; cmd++) {
281	    db_printf("%-12s", cmd->name);
282	    db_end_line(12);
283	}
284	if (table->aux_tablep == NULL)
285	    return;
286	for (aux_cmdp = table->aux_tablep; aux_cmdp < table->aux_tablep_end;
287	     aux_cmdp++) {
288	    db_printf("%-12s", (*aux_cmdp)->name);
289	    db_end_line(12);
290	}
291}
292
293static void
294db_command(last_cmdp, cmd_table, dopager)
295	struct command	**last_cmdp;	/* IN_OUT */
296	struct command_table *cmd_table;
297	int dopager;
298{
299	struct command	*cmd;
300	int		t;
301	char		modif[TOK_STRING_SIZE];
302	db_expr_t	addr, count;
303	boolean_t	have_addr = FALSE;
304	int		result;
305
306	t = db_read_token();
307	if (t == tEOL) {
308	    /* empty line repeats last command, at 'next' */
309	    cmd = *last_cmdp;
310	    addr = (db_expr_t)db_next;
311	    have_addr = FALSE;
312	    count = 1;
313	    modif[0] = '\0';
314	}
315	else if (t == tEXCL) {
316	    db_fncall((db_expr_t)0, (boolean_t)0, (db_expr_t)0, (char *)0);
317	    return;
318	}
319	else if (t != tIDENT) {
320	    db_printf("?\n");
321	    db_flush_lex();
322	    return;
323	}
324	else {
325	    /*
326	     * Search for command
327	     */
328	    while (cmd_table) {
329		result = db_cmd_search(db_tok_string,
330				       cmd_table,
331				       &cmd);
332		switch (result) {
333		    case CMD_NONE:
334			db_printf("No such command\n");
335			db_flush_lex();
336			return;
337		    case CMD_AMBIGUOUS:
338			db_printf("Ambiguous\n");
339			db_flush_lex();
340			return;
341		    case CMD_HELP:
342			db_cmd_list(cmd_table);
343			db_flush_lex();
344			return;
345		    default:
346			break;
347		}
348		if ((cmd_table = cmd->more) != NULL) {
349		    t = db_read_token();
350		    if (t != tIDENT) {
351			db_cmd_list(cmd_table);
352			db_flush_lex();
353			return;
354		    }
355		}
356	    }
357
358	    if ((cmd->flag & CS_OWN) == 0) {
359		/*
360		 * Standard syntax:
361		 * command [/modifier] [addr] [,count]
362		 */
363		t = db_read_token();
364		if (t == tSLASH) {
365		    t = db_read_token();
366		    if (t != tIDENT) {
367			db_printf("Bad modifier\n");
368			db_flush_lex();
369			return;
370		    }
371		    db_strcpy(modif, db_tok_string);
372		}
373		else {
374		    db_unread_token(t);
375		    modif[0] = '\0';
376		}
377
378		if (db_expression(&addr)) {
379		    db_dot = (db_addr_t) addr;
380		    db_last_addr = db_dot;
381		    have_addr = TRUE;
382		}
383		else {
384		    addr = (db_expr_t) db_dot;
385		    have_addr = FALSE;
386		}
387		t = db_read_token();
388		if (t == tCOMMA) {
389		    if (!db_expression(&count)) {
390			db_printf("Count missing\n");
391			db_flush_lex();
392			return;
393		    }
394		}
395		else {
396		    db_unread_token(t);
397		    count = -1;
398		}
399		if ((cmd->flag & CS_MORE) == 0) {
400		    db_skip_to_eol();
401		}
402	    }
403	}
404	*last_cmdp = cmd;
405	if (cmd != 0) {
406	    /*
407	     * Execute the command.
408	     */
409	    if (dopager)
410		db_enable_pager();
411	    else
412		db_disable_pager();
413	    (*cmd->fcn)(addr, have_addr, count, modif);
414	    if (dopager)
415		db_disable_pager();
416
417	    if (cmd->flag & CS_SET_DOT) {
418		/*
419		 * If command changes dot, set dot to
420		 * previous address displayed (if 'ed' style).
421		 */
422		if (db_ed_style) {
423		    db_dot = db_prev;
424		}
425		else {
426		    db_dot = db_next;
427		}
428	    }
429	    else {
430		/*
431		 * If command does not change dot,
432		 * set 'next' location to be the same.
433		 */
434		db_next = db_dot;
435	    }
436	}
437}
438
439/*
440 * At least one non-optional command must be implemented using
441 * DB_COMMAND() so that db_cmd_set gets created.  Here is one.
442 */
443DB_COMMAND(panic, db_panic)
444{
445	db_disable_pager();
446	panic("from debugger");
447}
448
449void
450db_command_loop()
451{
452	/*
453	 * Initialize 'prev' and 'next' to dot.
454	 */
455	db_prev = db_dot;
456	db_next = db_dot;
457
458	db_cmd_loop_done = 0;
459	while (!db_cmd_loop_done) {
460	    if (db_print_position() != 0)
461		db_printf("\n");
462
463	    db_printf("db> ");
464	    (void) db_read_line();
465
466	    db_command(&db_last_command, &db_command_table, /* dopager */ 1);
467	}
468}
469
470/*
471 * Execute a command on behalf of a script.  The caller is responsible for
472 * making sure that the command string is < DB_MAXLINE or it will be
473 * truncated.
474 *
475 * XXXRW: Runs by injecting faked input into DDB input stream; it would be
476 * nicer to use an alternative approach that didn't mess with the previous
477 * command buffer.
478 */
479void
480db_command_script(const char *command)
481{
482	db_prev = db_next = db_dot;
483	db_inject_line(command);
484	db_command(&db_last_command, &db_command_table, /* dopager */ 0);
485}
486
487void
488db_error(s)
489	const char *s;
490{
491	if (s)
492	    db_printf("%s", s);
493	db_flush_lex();
494	kdb_reenter();
495}
496
497
498/*
499 * Call random function:
500 * !expr(arg,arg,arg)
501 */
502
503/* The generic implementation supports a maximum of 10 arguments. */
504typedef db_expr_t __db_f(db_expr_t, db_expr_t, db_expr_t, db_expr_t,
505    db_expr_t, db_expr_t, db_expr_t, db_expr_t, db_expr_t, db_expr_t);
506
507static __inline int
508db_fncall_generic(db_expr_t addr, db_expr_t *rv, int nargs, db_expr_t args[])
509{
510	__db_f *f = (__db_f *)addr;
511
512	if (nargs > 10) {
513		db_printf("Too many arguments (max 10)\n");
514		return (0);
515	}
516	*rv = (*f)(args[0], args[1], args[2], args[3], args[4], args[5],
517	    args[6], args[7], args[8], args[9]);
518	return (1);
519}
520
521static void
522db_fncall(dummy1, dummy2, dummy3, dummy4)
523	db_expr_t	dummy1;
524	boolean_t	dummy2;
525	db_expr_t	dummy3;
526	char *		dummy4;
527{
528	db_expr_t	fn_addr;
529	db_expr_t	args[DB_MAXARGS];
530	int		nargs = 0;
531	db_expr_t	retval;
532	int		t;
533
534	if (!db_expression(&fn_addr)) {
535	    db_printf("Bad function\n");
536	    db_flush_lex();
537	    return;
538	}
539
540	t = db_read_token();
541	if (t == tLPAREN) {
542	    if (db_expression(&args[0])) {
543		nargs++;
544		while ((t = db_read_token()) == tCOMMA) {
545		    if (nargs == DB_MAXARGS) {
546			db_printf("Too many arguments (max %d)\n", DB_MAXARGS);
547			db_flush_lex();
548			return;
549		    }
550		    if (!db_expression(&args[nargs])) {
551			db_printf("Argument missing\n");
552			db_flush_lex();
553			return;
554		    }
555		    nargs++;
556		}
557		db_unread_token(t);
558	    }
559	    if (db_read_token() != tRPAREN) {
560		db_printf("?\n");
561		db_flush_lex();
562		return;
563	    }
564	}
565	db_skip_to_eol();
566	db_disable_pager();
567
568	if (DB_CALL(fn_addr, &retval, nargs, args))
569		db_printf("= %#lr\n", (long)retval);
570}
571
572static void
573db_halt(db_expr_t dummy, boolean_t dummy2, db_expr_t dummy3, char *dummy4)
574{
575
576	cpu_halt();
577}
578
579static void
580db_kill(dummy1, dummy2, dummy3, dummy4)
581	db_expr_t	dummy1;
582	boolean_t	dummy2;
583	db_expr_t	dummy3;
584	char *		dummy4;
585{
586	db_expr_t old_radix, pid, sig;
587	struct proc *p;
588
589#define DB_ERROR(f)	do { db_printf f; db_flush_lex(); goto out; } while (0)
590
591	/*
592	 * PIDs and signal numbers are typically represented in base
593	 * 10, so make that the default here.  It can, of course, be
594	 * overridden by specifying a prefix.
595	 */
596	old_radix = db_radix;
597	db_radix = 10;
598	/* Retrieve arguments. */
599	if (!db_expression(&sig))
600		DB_ERROR(("Missing signal number\n"));
601	if (!db_expression(&pid))
602		DB_ERROR(("Missing process ID\n"));
603	db_skip_to_eol();
604	if (sig < 1 || sig > _SIG_MAXSIG)
605		DB_ERROR(("Signal number out of range\n"));
606
607	/*
608	 * Find the process in question.  allproc_lock is not needed
609	 * since we're in DDB.
610	 */
611	/* sx_slock(&allproc_lock); */
612	FOREACH_PROC_IN_SYSTEM(p)
613	    if (p->p_pid == pid)
614		    break;
615	/* sx_sunlock(&allproc_lock); */
616	if (p == NULL)
617		DB_ERROR(("Can't find process with pid %ld\n", (long) pid));
618
619	/* If it's already locked, bail; otherwise, do the deed. */
620	if (PROC_TRYLOCK(p) == 0)
621		DB_ERROR(("Can't lock process with pid %ld\n", (long) pid));
622	else {
623		psignal(p, sig);
624		PROC_UNLOCK(p);
625	}
626
627out:
628	db_radix = old_radix;
629#undef DB_ERROR
630}
631
632static void
633db_reset(dummy1, dummy2, dummy3, dummy4)
634	db_expr_t	dummy1;
635	boolean_t	dummy2;
636	db_expr_t	dummy3;
637	char *		dummy4;
638{
639
640	cpu_reset();
641}
642
643static void
644db_watchdog(dummy1, dummy2, dummy3, dummy4)
645	db_expr_t	dummy1;
646	boolean_t	dummy2;
647	db_expr_t	dummy3;
648	char *		dummy4;
649{
650	int i;
651
652	/*
653	 * XXX: It might make sense to be able to set the watchdog to a
654	 * XXX: timeout here so that failure or hang as a result of subsequent
655	 * XXX: ddb commands could be recovered by a reset.
656	 */
657
658	EVENTHANDLER_INVOKE(watchdog_list, 0, &i);
659}
660
661static void
662db_gdb(db_expr_t dummy1, boolean_t dummy2, db_expr_t dummy3, char *dummy4)
663{
664
665	if (kdb_dbbe_select("gdb") != 0)
666		db_printf("The remote GDB backend could not be selected.\n");
667	else
668		db_printf("Step to enter the remote GDB backend.\n");
669}
670
671static void
672db_stack_trace(db_expr_t tid, boolean_t hastid, db_expr_t count, char *modif)
673{
674	struct thread *td;
675	db_expr_t radix;
676	pid_t pid;
677	int t;
678
679	/*
680	 * We parse our own arguments. We don't like the default radix.
681	 */
682	radix = db_radix;
683	db_radix = 10;
684	hastid = db_expression(&tid);
685	t = db_read_token();
686	if (t == tCOMMA) {
687		if (!db_expression(&count)) {
688			db_printf("Count missing\n");
689			db_flush_lex();
690			return;
691		}
692	} else {
693		db_unread_token(t);
694		count = -1;
695	}
696	db_skip_to_eol();
697	db_radix = radix;
698
699	if (hastid) {
700		td = kdb_thr_lookup((lwpid_t)tid);
701		if (td == NULL)
702			td = kdb_thr_from_pid((pid_t)tid);
703		if (td == NULL) {
704			db_printf("Thread %d not found\n", (int)tid);
705			return;
706		}
707	} else
708		td = kdb_thread;
709	if (td->td_proc != NULL)
710		pid = td->td_proc->p_pid;
711	else
712		pid = -1;
713	db_printf("Tracing pid %d tid %ld td %p\n", pid, (long)td->td_tid, td);
714	db_trace_thread(td, count);
715}
716
717static void
718db_stack_trace_all(db_expr_t dummy, boolean_t dummy2, db_expr_t dummy3,
719    char *dummy4)
720{
721	struct proc *p;
722	struct thread *td;
723	jmp_buf jb;
724	void *prev_jb;
725
726	FOREACH_PROC_IN_SYSTEM(p) {
727		prev_jb = kdb_jmpbuf(jb);
728		if (setjmp(jb) == 0) {
729			FOREACH_THREAD_IN_PROC(p, td) {
730				db_printf("\nTracing command %s pid %d tid %ld td %p\n",
731					  p->p_comm, p->p_pid, (long)td->td_tid, td);
732				db_trace_thread(td, -1);
733				if (db_pager_quit) {
734					kdb_jmpbuf(prev_jb);
735					return;
736				}
737			}
738		}
739		kdb_jmpbuf(prev_jb);
740	}
741}
742