summaryrefslogtreecommitdiff
path: root/ddb/db_break.c
blob: 0d099420b61799878492a9e98c0c128835dae457 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
/*
 * Mach Operating System
 * Copyright (c) 1991,1990 Carnegie Mellon University
 * All Rights Reserved.
 *
 * Permission to use, copy, modify and distribute this software and its
 * documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 *
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 *
 * Carnegie Mellon requests users of this software to return to
 *
 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 *
 * any improvements or extensions that they make and grant Carnegie Mellon
 * the rights to redistribute these changes.
 */
/*
 *	Author: David B. Golub, Carnegie Mellon University
 *	Date:	7/90
 */

#if MACH_KDB


/*
 * Breakpoints.
 */
#include <mach/boolean.h>
#include <machine/db_machdep.h>
#include <machine/db_interface.h>
#include <ddb/db_lex.h>
#include <ddb/db_break.h>
#include <ddb/db_access.h>
#include <ddb/db_sym.h>
#include <ddb/db_variables.h>
#include <ddb/db_command.h>
#include <ddb/db_task_thread.h>
#include <ddb/db_output.h>
#include <ddb/db_cond.h>
#include <ddb/db_expr.h>

#define	NBREAKPOINTS	100
#define NTHREAD_LIST	(NBREAKPOINTS*3)

struct db_breakpoint	db_break_table[NBREAKPOINTS];
db_breakpoint_t		db_next_free_breakpoint = &db_break_table[0];
db_breakpoint_t		db_free_breakpoints = 0;
db_breakpoint_t		db_breakpoint_list = 0;

static struct db_thread_breakpoint	db_thread_break_list[NTHREAD_LIST];
static db_thread_breakpoint_t		db_free_thread_break_list = 0;
static boolean_t			db_thread_break_init = FALSE;
static int				db_breakpoint_number = 0;

db_breakpoint_t
db_breakpoint_alloc()
{
	db_breakpoint_t	bkpt;

	if ((bkpt = db_free_breakpoints) != 0) {
	    db_free_breakpoints = bkpt->link;
	    return (bkpt);
	}
	if (db_next_free_breakpoint == &db_break_table[NBREAKPOINTS]) {
	    db_printf("All breakpoints used.\n");
	    return (0);
	}
	bkpt = db_next_free_breakpoint;
	db_next_free_breakpoint++;

	return (bkpt);
}

void
db_breakpoint_free(bkpt)
	db_breakpoint_t	bkpt;
{
	bkpt->link = db_free_breakpoints;
	db_free_breakpoints = bkpt;
}

static int
db_add_thread_breakpoint(bkpt, task_thd, count, task_bpt)
	db_breakpoint_t bkpt;
	vm_offset_t task_thd;
	int count;
	boolean_t task_bpt;
{
	db_thread_breakpoint_t tp;

	if (db_thread_break_init == FALSE) {
	    for (tp = db_thread_break_list;
		tp < &db_thread_break_list[NTHREAD_LIST-1]; tp++)
		tp->tb_next = tp+1;
	    tp->tb_next = 0;
	    db_free_thread_break_list = db_thread_break_list;
	    db_thread_break_init = TRUE;
	}
	if (db_free_thread_break_list == 0)
	    return (-1);
	tp = db_free_thread_break_list;
	db_free_thread_break_list = tp->tb_next;
	tp->tb_is_task = task_bpt;
	tp->tb_task_thd = task_thd;
	tp->tb_count = count;
	tp->tb_init_count = count;
	tp->tb_cond = 0;
	tp->tb_number = ++db_breakpoint_number;
	tp->tb_next = bkpt->threads;
	bkpt->threads = tp;
	return(0);
}

static int
db_delete_thread_breakpoint(bkpt, task_thd)
	db_breakpoint_t bkpt;
	vm_offset_t task_thd;
{
	db_thread_breakpoint_t tp;
	db_thread_breakpoint_t *tpp;

	if (task_thd == 0) {
	    /* delete all the thread-breakpoints */

	    for (tpp = &bkpt->threads; (tp = *tpp) != 0; tpp = &tp->tb_next)
		db_cond_free(tp);

	    *tpp = db_free_thread_break_list;
	    db_free_thread_break_list = bkpt->threads;
	    bkpt->threads = 0;
	    return 0;
	} else {
	    /* delete the specified thread-breakpoint */

	    for (tpp = &bkpt->threads; (tp = *tpp) != 0; tpp = &tp->tb_next)
		if (tp->tb_task_thd == task_thd) {
		    db_cond_free(tp);
		    *tpp = tp->tb_next;
		    tp->tb_next = db_free_thread_break_list;
		    db_free_thread_break_list = tp;
		    return 0;
		}

	    return -1;	/* not found */
	}
}

static db_thread_breakpoint_t
db_find_thread_breakpoint(bkpt, thread)
	db_breakpoint_t bkpt;
	thread_t thread;
{
	db_thread_breakpoint_t tp;
	task_t task = (thread == THREAD_NULL)? TASK_NULL: thread->task;

	for (tp = bkpt->threads; tp; tp = tp->tb_next) {
	    if (tp->tb_is_task) {
		if (tp->tb_task_thd == (vm_offset_t)task)
		    break;
		continue;
	    }
	    if (tp->tb_task_thd == (vm_offset_t)thread || tp->tb_task_thd == 0)
		break;
	}
	return(tp);
}

db_thread_breakpoint_t
db_find_thread_breakpoint_here(task, addr)
	task_t		task;
	db_addr_t	addr;
{
	db_breakpoint_t bkpt;

	bkpt = db_find_breakpoint(task, addr);
	if (bkpt == 0)
	    return(0);
	return(db_find_thread_breakpoint(bkpt, current_thread()));
}

db_thread_breakpoint_t
db_find_breakpoint_number(num, bkptp)
	int num;
	db_breakpoint_t *bkptp;
{
	db_thread_breakpoint_t tp;
	db_breakpoint_t bkpt;

	for (bkpt = db_breakpoint_list; bkpt != 0; bkpt = bkpt->link) {
	    for (tp = bkpt->threads; tp; tp = tp->tb_next) {
		if (tp->tb_number == num) {
		    if (bkptp)
			*bkptp = bkpt;
		    return(tp);
		}
	    }
	}
	return(0);
}

static void
db_force_delete_breakpoint(bkpt, task_thd, is_task)
	db_breakpoint_t	bkpt;
	vm_offset_t  task_thd;
	boolean_t is_task;
{
	db_printf("deleted a stale breakpoint at ");
	if (bkpt->task == TASK_NULL || db_lookup_task(bkpt->task) >= 0)
	   db_task_printsym(bkpt->address, DB_STGY_PROC, bkpt->task);
	else
	   db_printf("%#X", bkpt->address);
	if (bkpt->task)
	   db_printf(" in task %X", bkpt->task);
	if (task_thd)
	   db_printf(" for %s %X", (is_task)? "task": "thread", task_thd);
	db_printf("\n");
	db_delete_thread_breakpoint(bkpt, task_thd);
}

void
db_check_breakpoint_valid(void)
{
	db_thread_breakpoint_t tbp, tbp_next;
	db_breakpoint_t bkpt, *bkptp;

	bkptp = &db_breakpoint_list;
	for (bkpt = *bkptp; bkpt; bkpt = *bkptp) {
	    if (bkpt->task != TASK_NULL) {
		if (db_lookup_task(bkpt->task) < 0) {
		    db_force_delete_breakpoint(bkpt, 0, FALSE);
		    *bkptp = bkpt->link;
		    db_breakpoint_free(bkpt);
		    continue;
		}
	    } else {
		for (tbp = bkpt->threads; tbp; tbp = tbp_next) {
		    tbp_next = tbp->tb_next;
		    if (tbp->tb_task_thd == 0)
			continue;
		    if ((tbp->tb_is_task &&
			 db_lookup_task((task_t)(tbp->tb_task_thd)) < 0) ||
			(!tbp->tb_is_task &&
			 db_lookup_thread((thread_t)(tbp->tb_task_thd)) < 0)) {
			db_force_delete_breakpoint(bkpt,
					tbp->tb_task_thd, tbp->tb_is_task);
		    }
		}
		if (bkpt->threads == 0) {
		    db_put_task_value(bkpt->address, BKPT_SIZE,
				 bkpt->bkpt_inst, bkpt->task);
		    *bkptp = bkpt->link;
		    db_breakpoint_free(bkpt);
		    continue;
		}
	    }
	    bkptp = &bkpt->link;
	}
}

db_breakpoint_t
db_set_breakpoint(task, addr, count, thread, task_bpt)
	task_t		task;
	db_addr_t	addr;
	int		count;
	thread_t	thread;
	boolean_t	task_bpt;
{
	db_breakpoint_t bkpt;
	db_breakpoint_t alloc_bkpt = 0;
	vm_offset_t task_thd;

	bkpt = db_find_breakpoint(task, addr);
	if (bkpt) {
	    if (thread == THREAD_NULL
		|| db_find_thread_breakpoint(bkpt, thread)) {
		db_printf("Already set.\n");
		return NULL;
	    }
	} else {
	    if (!DB_CHECK_ACCESS(addr, BKPT_SIZE, task)) {
		db_printf("Cannot set break point at %X\n", addr);
		return NULL;
	    }
	    alloc_bkpt = bkpt = db_breakpoint_alloc();
	    if (bkpt == 0) {
		db_printf("Too many breakpoints.\n");
		return NULL;
	    }
	    bkpt->task = task;
	    bkpt->flags = (task && thread == THREAD_NULL)?
				(BKPT_USR_GLOBAL|BKPT_1ST_SET): 0;
	    bkpt->address = addr;
	    bkpt->threads = 0;
	}
	if (db_breakpoint_list == 0)
	    db_breakpoint_number = 0;
	task_thd = (task_bpt)? (vm_offset_t)(thread->task): (vm_offset_t)thread;
	if (db_add_thread_breakpoint(bkpt, task_thd, count, task_bpt) < 0) {
	    if (alloc_bkpt)
		db_breakpoint_free(alloc_bkpt);
	    db_printf("Too many thread_breakpoints.\n");
	    return NULL;
	} else {
	    db_printf("set breakpoint #%d\n", db_breakpoint_number);
	    if (alloc_bkpt) {
		bkpt->link = db_breakpoint_list;
		db_breakpoint_list = bkpt;
	    }
	    return bkpt;
	}
}

void
db_delete_breakpoint(task, addr, task_thd)
	task_t	task;
	db_addr_t	addr;
	vm_offset_t	task_thd;
{
	db_breakpoint_t	bkpt;
	db_breakpoint_t	*prev;

	for (prev = &db_breakpoint_list; (bkpt = *prev) != 0;
					     prev = &bkpt->link) {
	    if ((bkpt->task == task
		   || (task != TASK_NULL && (bkpt->flags & BKPT_USR_GLOBAL)))
		&& bkpt->address == addr)
		break;
	}
	if (bkpt && (bkpt->flags & BKPT_SET_IN_MEM)) {
	    db_printf("cannot delete it now.\n");
	    return;
	}
	if (bkpt == 0
	    || db_delete_thread_breakpoint(bkpt, task_thd) < 0) {
	    db_printf("Not set.\n");
	    return;
	}
	if (bkpt->threads == 0) {
	    *prev = bkpt->link;
	    db_breakpoint_free(bkpt);
	}
}

db_breakpoint_t
db_find_breakpoint(task, addr)
	task_t	task;
	db_addr_t	addr;
{
	db_breakpoint_t	bkpt;

	for (bkpt = db_breakpoint_list; bkpt != 0; bkpt = bkpt->link) {
	    if ((bkpt->task == task
		  || (task != TASK_NULL && (bkpt->flags & BKPT_USR_GLOBAL)))
		&& bkpt->address == addr)
		return (bkpt);
	}
	return (0);
}

boolean_t
db_find_breakpoint_here(task, addr)
	task_t		task;
	db_addr_t	addr;
{
	db_breakpoint_t	bkpt;

	for (bkpt = db_breakpoint_list; bkpt != 0; bkpt = bkpt->link) {
	    if ((bkpt->task == task
		   || (task != TASK_NULL && (bkpt->flags & BKPT_USR_GLOBAL)))
                && bkpt->address == addr)
		return(TRUE);
	    if ((bkpt->flags & BKPT_USR_GLOBAL) == 0 &&
		  DB_PHYS_EQ(task, (vm_offset_t)addr, bkpt->task, (vm_offset_t)bkpt->address))
		return (TRUE);
	}
	return(FALSE);
}

boolean_t	db_breakpoints_inserted = TRUE;

void
db_set_breakpoints(void)
{
	db_breakpoint_t bkpt;
	task_t		task;
	db_expr_t	inst;
	task_t		cur_task;

	cur_task = (current_thread())? current_thread()->task: TASK_NULL;
	if (!db_breakpoints_inserted) {
	    for (bkpt = db_breakpoint_list; bkpt != 0; bkpt = bkpt->link) {
		if (bkpt->flags & BKPT_SET_IN_MEM)
		    continue;
		task = bkpt->task;
		if (bkpt->flags & BKPT_USR_GLOBAL) {
		    if ((bkpt->flags & BKPT_1ST_SET) == 0) {
		        if (cur_task == TASK_NULL)
			    continue;
		        task = cur_task;
		    } else
			bkpt->flags &= ~BKPT_1ST_SET;
		}
		if (DB_CHECK_ACCESS(bkpt->address, BKPT_SIZE, task)) {
		    inst = db_get_task_value(bkpt->address, BKPT_SIZE, FALSE,
								task);
		    if (inst == BKPT_SET(inst))
			continue;
		    bkpt->bkpt_inst = inst;
		    db_put_task_value(bkpt->address,
				BKPT_SIZE,
				BKPT_SET(bkpt->bkpt_inst), task);
		    bkpt->flags |= BKPT_SET_IN_MEM;
		} else {
		    db_printf("Warning: cannot set breakpoint at %X ",
				bkpt->address);
		    if (task)
			db_printf("in task %X\n", task);
		    else
			db_printf("in kernel space\n");
		}
	    }
	    db_breakpoints_inserted = TRUE;
	}
}

void
db_clear_breakpoints(void)
{
	db_breakpoint_t bkpt, *bkptp;
	task_t		task;
	task_t		cur_task;
	db_expr_t	inst;

	cur_task = (current_thread())? current_thread()->task: TASK_NULL;
	if (db_breakpoints_inserted) {
	    bkptp = &db_breakpoint_list;
	    for (bkpt = *bkptp; bkpt; bkpt = *bkptp) {
		task = bkpt->task;
		if (bkpt->flags & BKPT_USR_GLOBAL) {
		    if (cur_task == TASK_NULL) {
			bkptp = &bkpt->link;
			continue;
		    }
		    task = cur_task;
		}
		if ((bkpt->flags & BKPT_SET_IN_MEM)
		    && DB_CHECK_ACCESS(bkpt->address, BKPT_SIZE, task)) {
		    inst = db_get_task_value(bkpt->address, BKPT_SIZE, FALSE,
								task);
		    if (inst != BKPT_SET(inst)) {
			if (bkpt->flags & BKPT_USR_GLOBAL) {
			    bkptp = &bkpt->link;
			    continue;
			}
			db_force_delete_breakpoint(bkpt, 0, FALSE);
			*bkptp = bkpt->link;
		        db_breakpoint_free(bkpt);
			continue;
		    }
		    db_put_task_value(bkpt->address, BKPT_SIZE,
				 bkpt->bkpt_inst, task);
		    bkpt->flags &= ~BKPT_SET_IN_MEM;
		}
		bkptp = &bkpt->link;
	    }
	    db_breakpoints_inserted = FALSE;
	}
}

/*
 * Set a temporary breakpoint.
 * The instruction is changed immediately,
 * so the breakpoint does not have to be on the breakpoint list.
 */
db_breakpoint_t
db_set_temp_breakpoint(task, addr)
	task_t		task;
	db_addr_t	addr;
{
	db_breakpoint_t	bkpt;

	bkpt = db_breakpoint_alloc();
	if (bkpt == 0) {
	    db_printf("Too many breakpoints.\n");
	    return 0;
	}
	bkpt->task = task;
	bkpt->address = addr;
	bkpt->flags = BKPT_TEMP;
	bkpt->threads = 0;
	if (db_add_thread_breakpoint(bkpt, 0, 1, FALSE) < 0) {
	    if (bkpt)
		db_breakpoint_free(bkpt);
	    db_printf("Too many thread_breakpoints.\n");
	    return 0;
	}
	bkpt->bkpt_inst = db_get_task_value(bkpt->address, BKPT_SIZE,
						FALSE, task);
	db_put_task_value(bkpt->address, BKPT_SIZE,
				BKPT_SET(bkpt->bkpt_inst), task);
	return bkpt;
}

void
db_delete_temp_breakpoint(task, bkpt)
	task_t		task;
	db_breakpoint_t	bkpt;
{
	db_put_task_value(bkpt->address, BKPT_SIZE, bkpt->bkpt_inst, task);
	db_delete_thread_breakpoint(bkpt, 0);
	db_breakpoint_free(bkpt);
}

/*
 * List breakpoints.
 */
void
db_list_breakpoints(void)
{
	db_breakpoint_t	bkpt;

	if (db_breakpoint_list == 0) {
	    db_printf("No breakpoints set\n");
	    return;
	}

	db_printf(" No  Space    Thread      Cnt  Address(Cond)\n");
	for (bkpt = db_breakpoint_list;
	     bkpt != 0;
	     bkpt = bkpt->link)
	{
	    db_thread_breakpoint_t 	tp;
	    int				task_id;
	    int				thread_id;

	    if (bkpt->threads) {
		for (tp = bkpt->threads; tp; tp = tp->tb_next) {
		    db_printf("%3d  ", tp->tb_number);
		    if (bkpt->flags & BKPT_USR_GLOBAL)
			db_printf("user     ");
		    else if (bkpt->task == TASK_NULL)
			db_printf("kernel   ");
		    else if ((task_id = db_lookup_task(bkpt->task)) < 0)
			db_printf("%0*X ", 2*sizeof(vm_offset_t), bkpt->task);
		    else
			db_printf("task%-3d  ", task_id);
		    if (tp->tb_task_thd == 0) {
			db_printf("all         ");
		    } else {
			if (tp->tb_is_task) {
			    task_id = db_lookup_task((task_t)(tp->tb_task_thd));
			    if (task_id < 0)
				db_printf("%0*X    ", 2*sizeof(vm_offset_t),
					   tp->tb_task_thd);
			    else
				db_printf("task%03d     ", task_id);
			} else {
			    thread_t thd = (thread_t)(tp->tb_task_thd);
			    task_id = db_lookup_task(thd->task);
			    thread_id = db_lookup_task_thread(thd->task, thd);
			    if (task_id < 0 || thread_id < 0)
				db_printf("%0*X    ", 2*sizeof(vm_offset_t),
					   tp->tb_task_thd);
			    else
				db_printf("task%03d.%-3d ", task_id, thread_id);
			}
		    }
	    	    db_printf("%3d  ", tp->tb_init_count);
		    db_task_printsym(bkpt->address, DB_STGY_PROC, bkpt->task);
		    if (tp->tb_cond > 0) {
			db_printf("(");
			db_cond_print(tp);
			db_printf(")");
		    }
		    db_printf("\n");
		}
	    } else {
		if (bkpt->task == TASK_NULL)
		    db_printf("  ?  kernel   ");
		else
		    db_printf("%*X ", 2*sizeof(vm_offset_t), bkpt->task);
		db_printf("(?)              ");
		db_task_printsym(bkpt->address, DB_STGY_PROC, bkpt->task);
		db_printf("\n");
	    }
	}
}

/* Delete breakpoint */
/*ARGSUSED*/
void
db_delete_cmd(void)
{
	int n;
	thread_t thread;
	vm_offset_t task_thd;
	boolean_t user_global = FALSE;
	boolean_t task_bpt = FALSE;
	boolean_t user_space = FALSE;
	boolean_t thd_bpt = FALSE;
	db_expr_t addr;
	int t;

	t = db_read_token();
	if (t == tSLASH) {
	    t = db_read_token();
	    if (t != tIDENT) {
		db_printf("Bad modifier \"%s\"\n", db_tok_string);
		db_error(0);
	    }
	    user_global = db_option(db_tok_string, 'U');
	    user_space = (user_global)? TRUE: db_option(db_tok_string, 'u');
	    task_bpt = db_option(db_tok_string, 'T');
	    thd_bpt = db_option(db_tok_string, 't');
	    if (task_bpt && user_global)
		db_error("Cannot specify both 'T' and 'U' option\n");
	    t = db_read_token();
	}
	if (t == tHASH) {
	    db_thread_breakpoint_t tbp;
	    db_breakpoint_t bkpt = bkpt;

	    if (db_read_token() != tNUMBER) {
		db_printf("Bad break point number #%s\n", db_tok_string);
		db_error(0);
	    }
	    if ((tbp = db_find_breakpoint_number(db_tok_number, &bkpt)) == 0) {
	        db_printf("No such break point #%d\n", db_tok_number);
	        db_error(0);
	    }
	    db_delete_breakpoint(bkpt->task, bkpt->address, tbp->tb_task_thd);
	    return;
	}
	db_unread_token(t);
	if (!db_expression(&addr)) {
	    /*
	     *	We attempt to pick up the user_space indication from db_dot,
	     *	so that a plain "d" always works.
	     */
	    addr = (db_expr_t)db_dot;
	    if (!user_space && !DB_VALID_ADDRESS((vm_offset_t)addr, FALSE))
		user_space = TRUE;
	}
	if (!DB_VALID_ADDRESS((vm_offset_t) addr, user_space)) {
	    db_printf("Address %#X is not in %s space\n", addr,
			(user_space)? "user": "kernel");
	    db_error(0);
	}
	if (thd_bpt || task_bpt) {
	    for (n = 0; db_get_next_thread(&thread, n); n++) {
		if (thread == THREAD_NULL)
		    db_error("No active thread\n");
		if (task_bpt) {
		    if (thread->task == TASK_NULL)
			db_error("No task\n");
		    task_thd = (vm_offset_t) (thread->task);
		} else
		    task_thd = (user_global)? 0: (vm_offset_t) thread;
		db_delete_breakpoint(db_target_space(thread, user_space),
					(db_addr_t)addr, task_thd);
	    }
	} else {
	    db_delete_breakpoint(db_target_space(THREAD_NULL, user_space),
					 (db_addr_t)addr, 0);
	}
}

/* Set breakpoint with skip count */
/*ARGSUSED*/
void
db_breakpoint_cmd(addr, have_addr, count, modif)
	db_expr_t	addr;
	int		have_addr;
	db_expr_t	count;
	char *		modif;
{
	int n;
	thread_t thread;
	boolean_t user_global = db_option(modif, 'U');
	boolean_t task_bpt = db_option(modif, 'T');
	boolean_t user_space;

	if (count == -1)
	    count = 1;

	if (!task_bpt && db_option(modif,'t'))
	  task_bpt = TRUE;

	if (task_bpt && user_global)
	    db_error("Cannot specify both 'T' and 'U'\n");
	user_space = (user_global)? TRUE: db_option(modif, 'u');
	if (user_space && db_access_level < DB_ACCESS_CURRENT)
	    db_error("User space break point is not supported\n");
	if (!task_bpt && !DB_VALID_ADDRESS((vm_offset_t)addr, user_space)) {
	    /* if the user has explicitly specified user space,
	       do not insert a breakpoint into the kernel */
	    if (user_space)
	      db_error("Invalid user space address\n");
	    user_space = TRUE;
	    db_printf("%#X is in user space\n", addr);
	}
	if (db_option(modif, 't') || task_bpt) {
	    for (n = 0; db_get_next_thread(&thread, n); n++) {
		if (thread == THREAD_NULL)
		    db_error("No active thread\n");
		if (task_bpt && thread->task == TASK_NULL)
		    db_error("No task\n");
		if (db_access_level <= DB_ACCESS_CURRENT && user_space
			 && thread->task != db_current_task())
		    db_error("Cannot set break point in inactive user space\n");
		db_set_breakpoint(db_target_space(thread, user_space),
					(db_addr_t)addr, count,
					(user_global)? THREAD_NULL: thread,
					task_bpt);
	    }
	} else {
	    db_set_breakpoint(db_target_space(THREAD_NULL, user_space),
				 (db_addr_t)addr,
				 count, THREAD_NULL, FALSE);
	}
}

/* list breakpoints */
void
db_listbreak_cmd(void)
{
	db_list_breakpoints();
}

#endif /* MACH_KDB */