db_command.c revision 174914 
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 174914 2007-12-26 09:33:19Z 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	{ "run",	db_run_cmd,		CS_OWN,	0 },
145	{ "script",	db_script_cmd,		CS_OWN,	0 },
146	{ "scripts",	db_scripts_cmd,		0,	0 },
147	{ "unscript",	db_unscript_cmd,	CS_OWN,	0 },
148	{ "capture",	db_capture_cmd,		CS_OWN,	0 },
149	{ (char *)0, }
150};
151
152static struct command_table db_command_table = {
153	db_commands,
154	SET_BEGIN(db_cmd_set),
155	SET_LIMIT(db_cmd_set)
156};
157
158static struct command	*db_last_command = 0;
159
160/*
161 * if 'ed' style: 'dot' is set at start of last item printed,
162 * and '+' points to next line.
163 * Otherwise: 'dot' points to next item, '..' points to last.
164 */
165static boolean_t	db_ed_style = TRUE;
166
167/*
168 * Utility routine - discard tokens through end-of-line.
169 */
170void
171db_skip_to_eol()
172{
173	int	t;
174	do {
175	    t = db_read_token();
176	} while (t != tEOL);
177}
178
179/*
180 * Results of command search.
181 */
182#define	CMD_UNIQUE	0
183#define	CMD_FOUND	1
184#define	CMD_NONE	2
185#define	CMD_AMBIGUOUS	3
186#define	CMD_HELP	4
187
188static void	db_cmd_match(char *name, struct command *cmd,
189		    struct command **cmdp, int *resultp);
190static void	db_cmd_list(struct command_table *table);
191static int	db_cmd_search(char *name, struct command_table *table,
192		    struct command **cmdp);
193static void	db_command(struct command **last_cmdp,
194		    struct command_table *cmd_table, int dopager);
195
196/*
197 * Helper function to match a single command.
198 */
199static void
200db_cmd_match(name, cmd, cmdp, resultp)
201	char *		name;
202	struct command	*cmd;
203	struct command	**cmdp;	/* out */
204	int *		resultp;
205{
206	char *lp, *rp;
207	int c;
208
209	lp = name;
210	rp = cmd->name;
211	while ((c = *lp) == *rp) {
212		if (c == 0) {
213			/* complete match */
214			*cmdp = cmd;
215			*resultp = CMD_UNIQUE;
216			return;
217		}
218		lp++;
219		rp++;
220	}
221	if (c == 0) {
222		/* end of name, not end of command -
223		   partial match */
224		if (*resultp == CMD_FOUND) {
225			*resultp = CMD_AMBIGUOUS;
226			/* but keep looking for a full match -
227			   this lets us match single letters */
228		} else {
229			*cmdp = cmd;
230			*resultp = CMD_FOUND;
231		}
232	}
233}
234
235/*
236 * Search for command prefix.
237 */
238static int
239db_cmd_search(name, table, cmdp)
240	char *		name;
241	struct command_table *table;
242	struct command	**cmdp;	/* out */
243{
244	struct command	*cmd;
245	struct command	**aux_cmdp;
246	int		result = CMD_NONE;
247
248	for (cmd = table->table; cmd->name != 0; cmd++) {
249		db_cmd_match(name, cmd, cmdp, &result);
250		if (result == CMD_UNIQUE)
251			return (CMD_UNIQUE);
252	}
253	if (table->aux_tablep != NULL)
254		for (aux_cmdp = table->aux_tablep;
255		     aux_cmdp < table->aux_tablep_end;
256		     aux_cmdp++) {
257			db_cmd_match(name, *aux_cmdp, cmdp, &result);
258			if (result == CMD_UNIQUE)
259				return (CMD_UNIQUE);
260		}
261	if (result == CMD_NONE) {
262		/* check for 'help' */
263		if (name[0] == 'h' && name[1] == 'e'
264		    && name[2] == 'l' && name[3] == 'p')
265			result = CMD_HELP;
266	}
267	return (result);
268}
269
270static void
271db_cmd_list(table)
272	struct command_table *table;
273{
274	register struct command *cmd;
275	register struct command **aux_cmdp;
276
277	for (cmd = table->table; cmd->name != 0; cmd++) {
278	    db_printf("%-12s", cmd->name);
279	    db_end_line(12);
280	}
281	if (table->aux_tablep == NULL)
282	    return;
283	for (aux_cmdp = table->aux_tablep; aux_cmdp < table->aux_tablep_end;
284	     aux_cmdp++) {
285	    db_printf("%-12s", (*aux_cmdp)->name);
286	    db_end_line(12);
287	}
288}
289
290static void
291db_command(last_cmdp, cmd_table, dopager)
292	struct command	**last_cmdp;	/* IN_OUT */
293	struct command_table *cmd_table;
294	int dopager;
295{
296	struct command	*cmd;
297	int		t;
298	char		modif[TOK_STRING_SIZE];
299	db_expr_t	addr, count;
300	boolean_t	have_addr = FALSE;
301	int		result;
302
303	t = db_read_token();
304	if (t == tEOL) {
305	    /* empty line repeats last command, at 'next' */
306	    cmd = *last_cmdp;
307	    addr = (db_expr_t)db_next;
308	    have_addr = FALSE;
309	    count = 1;
310	    modif[0] = '\0';
311	}
312	else if (t == tEXCL) {
313	    db_fncall((db_expr_t)0, (boolean_t)0, (db_expr_t)0, (char *)0);
314	    return;
315	}
316	else if (t != tIDENT) {
317	    db_printf("?\n");
318	    db_flush_lex();
319	    return;
320	}
321	else {
322	    /*
323	     * Search for command
324	     */
325	    while (cmd_table) {
326		result = db_cmd_search(db_tok_string,
327				       cmd_table,
328				       &cmd);
329		switch (result) {
330		    case CMD_NONE:
331			db_printf("No such command\n");
332			db_flush_lex();
333			return;
334		    case CMD_AMBIGUOUS:
335			db_printf("Ambiguous\n");
336			db_flush_lex();
337			return;
338		    case CMD_HELP:
339			db_cmd_list(cmd_table);
340			db_flush_lex();
341			return;
342		    default:
343			break;
344		}
345		if ((cmd_table = cmd->more) != NULL) {
346		    t = db_read_token();
347		    if (t != tIDENT) {
348			db_cmd_list(cmd_table);
349			db_flush_lex();
350			return;
351		    }
352		}
353	    }
354
355	    if ((cmd->flag & CS_OWN) == 0) {
356		/*
357		 * Standard syntax:
358		 * command [/modifier] [addr] [,count]
359		 */
360		t = db_read_token();
361		if (t == tSLASH) {
362		    t = db_read_token();
363		    if (t != tIDENT) {
364			db_printf("Bad modifier\n");
365			db_flush_lex();
366			return;
367		    }
368		    db_strcpy(modif, db_tok_string);
369		}
370		else {
371		    db_unread_token(t);
372		    modif[0] = '\0';
373		}
374
375		if (db_expression(&addr)) {
376		    db_dot = (db_addr_t) addr;
377		    db_last_addr = db_dot;
378		    have_addr = TRUE;
379		}
380		else {
381		    addr = (db_expr_t) db_dot;
382		    have_addr = FALSE;
383		}
384		t = db_read_token();
385		if (t == tCOMMA) {
386		    if (!db_expression(&count)) {
387			db_printf("Count missing\n");
388			db_flush_lex();
389			return;
390		    }
391		}
392		else {
393		    db_unread_token(t);
394		    count = -1;
395		}
396		if ((cmd->flag & CS_MORE) == 0) {
397		    db_skip_to_eol();
398		}
399	    }
400	}
401	*last_cmdp = cmd;
402	if (cmd != 0) {
403	    /*
404	     * Execute the command.
405	     */
406	    if (dopager)
407		db_enable_pager();
408	    else
409		db_disable_pager();
410	    (*cmd->fcn)(addr, have_addr, count, modif);
411	    if (dopager)
412		db_disable_pager();
413
414	    if (cmd->flag & CS_SET_DOT) {
415		/*
416		 * If command changes dot, set dot to
417		 * previous address displayed (if 'ed' style).
418		 */
419		if (db_ed_style) {
420		    db_dot = db_prev;
421		}
422		else {
423		    db_dot = db_next;
424		}
425	    }
426	    else {
427		/*
428		 * If command does not change dot,
429		 * set 'next' location to be the same.
430		 */
431		db_next = db_dot;
432	    }
433	}
434}
435
436/*
437 * At least one non-optional command must be implemented using
438 * DB_COMMAND() so that db_cmd_set gets created.  Here is one.
439 */
440DB_COMMAND(panic, db_panic)
441{
442	db_disable_pager();
443	panic("from debugger");
444}
445
446void
447db_command_loop()
448{
449	/*
450	 * Initialize 'prev' and 'next' to dot.
451	 */
452	db_prev = db_dot;
453	db_next = db_dot;
454
455	db_cmd_loop_done = 0;
456	while (!db_cmd_loop_done) {
457	    if (db_print_position() != 0)
458		db_printf("\n");
459
460	    db_printf("db> ");
461	    (void) db_read_line();
462
463	    db_command(&db_last_command, &db_command_table, /* dopager */ 1);
464	}
465}
466
467/*
468 * Execute a command on behalf of a script.  The caller is responsible for
469 * making sure that the command string is < DB_MAXLINE or it will be
470 * truncated.
471 *
472 * XXXRW: Runs by injecting faked input into DDB input stream; it would be
473 * nicer to use an alternative approach that didn't mess with the previous
474 * command buffer.
475 */
476void
477db_command_script(const char *command)
478{
479	db_prev = db_next = db_dot;
480	db_inject_line(command);
481	db_command(&db_last_command, &db_command_table, /* dopager */ 0);
482}
483
484void
485db_error(s)
486	const char *s;
487{
488	if (s)
489	    db_printf("%s", s);
490	db_flush_lex();
491	kdb_reenter();
492}
493
494
495/*
496 * Call random function:
497 * !expr(arg,arg,arg)
498 */
499
500/* The generic implementation supports a maximum of 10 arguments. */
501typedef db_expr_t __db_f(db_expr_t, db_expr_t, db_expr_t, db_expr_t,
502    db_expr_t, db_expr_t, db_expr_t, db_expr_t, db_expr_t, db_expr_t);
503
504static __inline int
505db_fncall_generic(db_expr_t addr, db_expr_t *rv, int nargs, db_expr_t args[])
506{
507	__db_f *f = (__db_f *)addr;
508
509	if (nargs > 10) {
510		db_printf("Too many arguments (max 10)\n");
511		return (0);
512	}
513	*rv = (*f)(args[0], args[1], args[2], args[3], args[4], args[5],
514	    args[6], args[7], args[8], args[9]);
515	return (1);
516}
517
518static void
519db_fncall(dummy1, dummy2, dummy3, dummy4)
520	db_expr_t	dummy1;
521	boolean_t	dummy2;
522	db_expr_t	dummy3;
523	char *		dummy4;
524{
525	db_expr_t	fn_addr;
526	db_expr_t	args[DB_MAXARGS];
527	int		nargs = 0;
528	db_expr_t	retval;
529	int		t;
530
531	if (!db_expression(&fn_addr)) {
532	    db_printf("Bad function\n");
533	    db_flush_lex();
534	    return;
535	}
536
537	t = db_read_token();
538	if (t == tLPAREN) {
539	    if (db_expression(&args[0])) {
540		nargs++;
541		while ((t = db_read_token()) == tCOMMA) {
542		    if (nargs == DB_MAXARGS) {
543			db_printf("Too many arguments (max %d)\n", DB_MAXARGS);
544			db_flush_lex();
545			return;
546		    }
547		    if (!db_expression(&args[nargs])) {
548			db_printf("Argument missing\n");
549			db_flush_lex();
550			return;
551		    }
552		    nargs++;
553		}
554		db_unread_token(t);
555	    }
556	    if (db_read_token() != tRPAREN) {
557		db_printf("?\n");
558		db_flush_lex();
559		return;
560	    }
561	}
562	db_skip_to_eol();
563	db_disable_pager();
564
565	if (DB_CALL(fn_addr, &retval, nargs, args))
566		db_printf("= %#lr\n", (long)retval);
567}
568
569static void
570db_halt(db_expr_t dummy, boolean_t dummy2, db_expr_t dummy3, char *dummy4)
571{
572
573	cpu_halt();
574}
575
576static void
577db_kill(dummy1, dummy2, dummy3, dummy4)
578	db_expr_t	dummy1;
579	boolean_t	dummy2;
580	db_expr_t	dummy3;
581	char *		dummy4;
582{
583	db_expr_t old_radix, pid, sig;
584	struct proc *p;
585
586#define DB_ERROR(f)	do { db_printf f; db_flush_lex(); goto out; } while (0)
587
588	/*
589	 * PIDs and signal numbers are typically represented in base
590	 * 10, so make that the default here.  It can, of course, be
591	 * overridden by specifying a prefix.
592	 */
593	old_radix = db_radix;
594	db_radix = 10;
595	/* Retrieve arguments. */
596	if (!db_expression(&sig))
597		DB_ERROR(("Missing signal number\n"));
598	if (!db_expression(&pid))
599		DB_ERROR(("Missing process ID\n"));
600	db_skip_to_eol();
601	if (sig < 0 || sig > _SIG_MAXSIG)
602		DB_ERROR(("Signal number out of range\n"));
603
604	/*
605	 * Find the process in question.  allproc_lock is not needed
606	 * since we're in DDB.
607	 */
608	/* sx_slock(&allproc_lock); */
609	FOREACH_PROC_IN_SYSTEM(p)
610	    if (p->p_pid == pid)
611		    break;
612	/* sx_sunlock(&allproc_lock); */
613	if (p == NULL)
614		DB_ERROR(("Can't find process with pid %ld\n", (long) pid));
615
616	/* If it's already locked, bail; otherwise, do the deed. */
617	if (PROC_TRYLOCK(p) == 0)
618		DB_ERROR(("Can't lock process with pid %ld\n", (long) pid));
619	else {
620		psignal(p, sig);
621		PROC_UNLOCK(p);
622	}
623
624out:
625	db_radix = old_radix;
626#undef DB_ERROR
627}
628
629static void
630db_reset(dummy1, dummy2, dummy3, dummy4)
631	db_expr_t	dummy1;
632	boolean_t	dummy2;
633	db_expr_t	dummy3;
634	char *		dummy4;
635{
636
637	cpu_reset();
638}
639
640static void
641db_watchdog(dummy1, dummy2, dummy3, dummy4)
642	db_expr_t	dummy1;
643	boolean_t	dummy2;
644	db_expr_t	dummy3;
645	char *		dummy4;
646{
647	int i;
648
649	/*
650	 * XXX: It might make sense to be able to set the watchdog to a
651	 * XXX: timeout here so that failure or hang as a result of subsequent
652	 * XXX: ddb commands could be recovered by a reset.
653	 */
654
655	EVENTHANDLER_INVOKE(watchdog_list, 0, &i);
656}
657
658static void
659db_gdb(db_expr_t dummy1, boolean_t dummy2, db_expr_t dummy3, char *dummy4)
660{
661
662	if (kdb_dbbe_select("gdb") != 0)
663		db_printf("The remote GDB backend could not be selected.\n");
664	else
665		db_printf("Step to enter the remote GDB backend.\n");
666}
667
668static void
669db_stack_trace(db_expr_t tid, boolean_t hastid, db_expr_t count, char *modif)
670{
671	struct thread *td;
672	db_expr_t radix;
673	pid_t pid;
674	int t;
675
676	/*
677	 * We parse our own arguments. We don't like the default radix.
678	 */
679	radix = db_radix;
680	db_radix = 10;
681	hastid = db_expression(&tid);
682	t = db_read_token();
683	if (t == tCOMMA) {
684		if (!db_expression(&count)) {
685			db_printf("Count missing\n");
686			db_flush_lex();
687			return;
688		}
689	} else {
690		db_unread_token(t);
691		count = -1;
692	}
693	db_skip_to_eol();
694	db_radix = radix;
695
696	if (hastid) {
697		td = kdb_thr_lookup((lwpid_t)tid);
698		if (td == NULL)
699			td = kdb_thr_from_pid((pid_t)tid);
700		if (td == NULL) {
701			db_printf("Thread %d not found\n", (int)tid);
702			return;
703		}
704	} else
705		td = kdb_thread;
706	if (td->td_proc != NULL)
707		pid = td->td_proc->p_pid;
708	else
709		pid = -1;
710	db_printf("Tracing pid %d tid %ld td %p\n", pid, (long)td->td_tid, td);
711	db_trace_thread(td, count);
712}
713
714static void
715db_stack_trace_all(db_expr_t dummy, boolean_t dummy2, db_expr_t dummy3,
716    char *dummy4)
717{
718	struct proc *p;
719	struct thread *td;
720	jmp_buf jb;
721	void *prev_jb;
722
723	FOREACH_PROC_IN_SYSTEM(p) {
724		prev_jb = kdb_jmpbuf(jb);
725		if (setjmp(jb) == 0) {
726			FOREACH_THREAD_IN_PROC(p, td) {
727				db_printf("\nTracing command %s pid %d tid %ld td %p\n",
728					  p->p_comm, p->p_pid, (long)td->td_tid, td);
729				db_trace_thread(td, -1);
730				if (db_pager_quit) {
731					kdb_jmpbuf(prev_jb);
732					return;
733				}
734			}
735		}
736		kdb_jmpbuf(prev_jb);
737	}
738}
739