1/*-
2 * SPDX-License-Identifier: MIT-CMU
3 *
4 * Mach Operating System
5 * Copyright (c) 1991,1990 Carnegie Mellon University
6 * All Rights Reserved.
7 *
8 * Permission to use, copy, modify and distribute this software and its
9 * documentation is hereby granted, provided that both the copyright
10 * notice and this permission notice appear in all copies of the
11 * software, derivative works or modified versions, and any portions
12 * thereof, and that both notices appear in supporting documentation.
13 *
14 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS
15 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
16 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
17 *
18 * Carnegie Mellon requests users of this software to return to
19 *
20 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
21 *  School of Computer Science
22 *  Carnegie Mellon University
23 *  Pittsburgh PA 15213-3890
24 *
25 * any improvements or extensions that they make and grant Carnegie the
26 * rights to redistribute these changes.
27 *
28 */
29/*
30 *	Author: David B. Golub, Carnegie Mellon University
31 *	Date:	7/90
32 */
33/*
34 * Breakpoints.
35 */
36
37#include <sys/param.h>
38#include <sys/systm.h>
39#include <sys/kdb.h>
40
41#include <vm/vm.h>
42#include <vm/vm_kern.h>
43
44#include <machine/kdb.h>
45
46#include <ddb/ddb.h>
47#include <ddb/db_break.h>
48#include <ddb/db_access.h>
49#include <ddb/db_sym.h>
50
51struct db_breakpoint_type {
52	db_breakpoint_t		db_next_free_breakpoint;
53	db_breakpoint_t		db_breakpoint_limit;
54	db_breakpoint_t		db_free_breakpoints;
55	db_breakpoint_t		db_breakpoint_list;
56};
57
58#define	NBREAKPOINTS	100
59static struct db_breakpoint	db_break_table[NBREAKPOINTS];
60
61static struct db_breakpoint_type db_breakpoint = {
62	.db_next_free_breakpoint = &db_break_table[0],
63	.db_breakpoint_limit = &db_break_table[NBREAKPOINTS],
64	.db_free_breakpoints = NULL,
65	.db_breakpoint_list = NULL,
66};
67
68#ifdef HAS_HW_BREAKPOINT
69static struct db_breakpoint	db_hbreak_table[NHBREAKPOINTS];
70
71static struct db_breakpoint_type db_hbreakpoint = {
72	.db_next_free_breakpoint = &db_hbreak_table[0],
73	.db_breakpoint_limit = &db_hbreak_table[NHBREAKPOINTS],
74	.db_free_breakpoints = NULL,
75	.db_breakpoint_list = NULL,
76};
77#endif
78
79static db_breakpoint_t	db_breakpoint_alloc(
80	struct db_breakpoint_type *bkpt_type);
81static void	db_breakpoint_free(struct db_breakpoint_type *bkpt_typ,
82	db_breakpoint_t bkpt);
83static void	db_delete_breakpoint(struct db_breakpoint_type *bkpt_type,
84	vm_map_t map, db_addr_t addr);
85static db_breakpoint_t	db_find_breakpoint(struct db_breakpoint_type *bkpt_type,
86	vm_map_t map, db_addr_t addr);
87static void	db_list_breakpoints(void);
88static bool	db_set_breakpoint(struct db_breakpoint_type *bkpt_type,
89	vm_map_t map, db_addr_t addr, int count);
90
91static db_breakpoint_t
92db_breakpoint_alloc(struct db_breakpoint_type *bkpt_type)
93{
94	register db_breakpoint_t	bkpt;
95
96	if ((bkpt = bkpt_type->db_free_breakpoints) != 0) {
97	    bkpt_type->db_free_breakpoints = bkpt->link;
98	    return (bkpt);
99	}
100	if (bkpt_type->db_next_free_breakpoint ==
101	    bkpt_type->db_breakpoint_limit) {
102	    db_printf("All breakpoints used.\n");
103	    return (0);
104	}
105	bkpt = bkpt_type->db_next_free_breakpoint;
106	bkpt_type->db_next_free_breakpoint++;
107
108	return (bkpt);
109}
110
111static void
112db_breakpoint_free(struct db_breakpoint_type *bkpt_type, db_breakpoint_t bkpt)
113{
114	bkpt->link = bkpt_type->db_free_breakpoints;
115	bkpt_type->db_free_breakpoints = bkpt;
116}
117
118static bool
119db_set_breakpoint(struct db_breakpoint_type *bkpt_type, vm_map_t map,
120    db_addr_t addr, int count)
121{
122	register db_breakpoint_t	bkpt;
123
124	if (db_find_breakpoint(bkpt_type, map, addr)) {
125	    db_printf("Already set.\n");
126	    return (false);
127	}
128
129	bkpt = db_breakpoint_alloc(bkpt_type);
130	if (bkpt == 0) {
131	    db_printf("Too many breakpoints.\n");
132	    return (false);
133	}
134
135	bkpt->map = map;
136	bkpt->address = addr;
137	bkpt->flags = 0;
138	bkpt->init_count = count;
139	bkpt->count = count;
140
141	bkpt->link = bkpt_type->db_breakpoint_list;
142	bkpt_type->db_breakpoint_list = bkpt;
143
144	return (true);
145}
146
147static void
148db_delete_breakpoint(struct db_breakpoint_type *bkpt_type, vm_map_t map,
149    db_addr_t addr)
150{
151	register db_breakpoint_t	bkpt;
152	register db_breakpoint_t	*prev;
153
154	for (prev = &bkpt_type->db_breakpoint_list;
155	     (bkpt = *prev) != 0;
156	     prev = &bkpt->link) {
157	    if (db_map_equal(bkpt->map, map) &&
158		(bkpt->address == addr)) {
159		*prev = bkpt->link;
160		break;
161	    }
162	}
163	if (bkpt == 0) {
164	    db_printf("Not set.\n");
165	    return;
166	}
167
168	db_breakpoint_free(bkpt_type, bkpt);
169}
170
171static db_breakpoint_t
172db_find_breakpoint(struct db_breakpoint_type *bkpt_type, vm_map_t map,
173    db_addr_t addr)
174{
175	register db_breakpoint_t	bkpt;
176
177	for (bkpt = bkpt_type->db_breakpoint_list;
178	     bkpt != 0;
179	     bkpt = bkpt->link)
180	{
181	    if (db_map_equal(bkpt->map, map) &&
182		(bkpt->address == addr))
183		return (bkpt);
184	}
185	return (0);
186}
187
188db_breakpoint_t
189db_find_breakpoint_here(db_addr_t addr)
190{
191	db_breakpoint_t bkpt;
192
193	bkpt = db_find_breakpoint(&db_breakpoint, db_map_addr(addr), addr);
194#ifdef HAS_HW_BREAKPOINT
195	if (bkpt == NULL)
196		bkpt = db_find_breakpoint(&db_hbreakpoint, db_map_addr(addr),
197		    addr);
198#endif
199
200	return (bkpt);
201}
202
203static bool	db_breakpoints_inserted = true;
204
205#ifndef BKPT_WRITE
206#define	BKPT_WRITE(addr, storage)				\
207do {								\
208	*storage = db_get_value(addr, BKPT_SIZE, false);	\
209	db_put_value(addr, BKPT_SIZE, BKPT_SET(*storage));	\
210} while (0)
211#endif
212
213#ifndef BKPT_CLEAR
214#define	BKPT_CLEAR(addr, storage) \
215	db_put_value(addr, BKPT_SIZE, *storage)
216#endif
217
218/*
219 * Set software breakpoints.
220 */
221void
222db_set_breakpoints(void)
223{
224	register db_breakpoint_t	bkpt;
225
226	if (!db_breakpoints_inserted) {
227		for (bkpt = db_breakpoint.db_breakpoint_list;
228		     bkpt != 0;
229		     bkpt = bkpt->link)
230			if (db_map_current(bkpt->map)) {
231				BKPT_WRITE(bkpt->address, &bkpt->bkpt_inst);
232			}
233		db_breakpoints_inserted = true;
234	}
235}
236
237/*
238 * Clean software breakpoints.
239 */
240void
241db_clear_breakpoints(void)
242{
243	register db_breakpoint_t	bkpt;
244
245	if (db_breakpoints_inserted) {
246		for (bkpt = db_breakpoint.db_breakpoint_list;
247		     bkpt != 0;
248		     bkpt = bkpt->link)
249			if (db_map_current(bkpt->map)) {
250				BKPT_CLEAR(bkpt->address, &bkpt->bkpt_inst);
251			}
252		db_breakpoints_inserted = false;
253	}
254}
255
256/*
257 * List software breakpoints.
258 */
259static void
260db_list_breakpoints(void)
261{
262	register db_breakpoint_t	bkpt;
263
264	if (db_breakpoint.db_breakpoint_list == 0) {
265	    db_printf("No breakpoints set\n");
266	    return;
267	}
268
269	db_printf(" Map      Count    Address\n");
270	for (bkpt = db_breakpoint.db_breakpoint_list;
271	     bkpt != 0;
272	     bkpt = bkpt->link) {
273	    db_printf("%s%8p %5d    ",
274		      db_map_current(bkpt->map) ? "*" : " ",
275		      (void *)bkpt->map, bkpt->init_count);
276	    db_printsym(bkpt->address, DB_STGY_PROC);
277	    db_printf("\n");
278	}
279}
280
281/*
282 * Delete software breakpoint
283 */
284/*ARGSUSED*/
285void
286db_delete_cmd(db_expr_t addr, bool have_addr, db_expr_t count, char *modif)
287{
288	db_delete_breakpoint(&db_breakpoint, db_map_addr(addr),
289	    (db_addr_t)addr);
290}
291
292/*
293 * Set software breakpoint with skip count
294 */
295/*ARGSUSED*/
296void
297db_breakpoint_cmd(db_expr_t addr, bool have_addr, db_expr_t count, char *modif)
298{
299	if (count == -1)
300	    count = 1;
301
302	db_set_breakpoint(&db_breakpoint, db_map_addr(addr), (db_addr_t)addr,
303	    count);
304}
305
306#ifdef HAS_HW_BREAKPOINT
307/*
308 * Delete hardware breakpoint
309 */
310void
311db_deletehbreak_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
312    char *modif)
313{
314	if (count == -1)
315	    count = 1;
316
317	if (kdb_cpu_clr_breakpoint(addr) != 0) {
318		db_printf("hardware breakpoint could not be delete\n");
319		return;
320	}
321
322	db_delete_breakpoint(&db_hbreakpoint, db_map_addr(addr),
323	    (db_addr_t)addr);
324}
325
326/*
327 * Set hardware breakpoint
328 */
329void
330db_hbreakpoint_cmd(db_expr_t addr, bool have_addr, db_expr_t count, char *modif)
331{
332	if (count == -1)
333	    count = 1;
334
335	if (!db_set_breakpoint(&db_hbreakpoint, db_map_addr(addr),
336	    (db_addr_t)addr, count))
337		return;
338
339	if (kdb_cpu_set_breakpoint(addr) != 0) {
340		db_printf("hardware breakpoint could not be set\n");
341		db_delete_breakpoint(&db_hbreakpoint, db_map_addr(addr),
342		    (db_addr_t)addr);
343	}
344}
345#endif
346
347/* list breakpoints */
348void
349db_listbreak_cmd(db_expr_t dummy1, bool dummy2, db_expr_t dummy3, char *dummy4)
350{
351	db_list_breakpoints();
352#ifdef HAS_HW_BREAKPOINT
353	db_md_list_breakpoints();
354#endif
355}
356
357/*
358 *	We want ddb to be usable before most of the kernel has been
359 *	initialized.  In particular, current_thread() or kernel_map
360 *	(or both) may be null.
361 */
362
363bool
364db_map_equal(vm_map_t map1, vm_map_t map2)
365{
366	return ((map1 == map2) ||
367		((map1 == NULL) && (map2 == kernel_map)) ||
368		((map1 == kernel_map) && (map2 == NULL)));
369}
370
371bool
372db_map_current(vm_map_t map)
373{
374#if 0
375	thread_t	thread;
376
377	return ((map == NULL) ||
378		(map == kernel_map) ||
379		(((thread = current_thread()) != NULL) &&
380		 (map == thread->task->map)));
381#else
382	return (true);
383#endif
384}
385
386vm_map_t
387db_map_addr(vm_offset_t addr)
388{
389#if 0
390	thread_t	thread;
391
392	/*
393	 *	We want to return kernel_map for all
394	 *	non-user addresses, even when debugging
395	 *	kernel tasks with their own maps.
396	 */
397
398	if ((VM_MIN_ADDRESS <= addr) &&
399	    (addr < VM_MAX_ADDRESS) &&
400	    ((thread = current_thread()) != NULL))
401	    return thread->task->map;
402	else
403#endif
404	    return kernel_map;
405}
406