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/*
28 *	Author: David B. Golub, Carnegie Mellon University
29 *	Date:	7/90
30 */
31/*
32 * Breakpoints.
33 */
34
35#include <sys/cdefs.h>
36__FBSDID("$FreeBSD$");
37
38#include <sys/param.h>
39
40#include <vm/vm.h>
41#include <vm/vm_kern.h>
42
43#include <ddb/ddb.h>
44#include <ddb/db_break.h>
45#include <ddb/db_access.h>
46#include <ddb/db_sym.h>
47
48#define	NBREAKPOINTS	100
49static struct db_breakpoint	db_break_table[NBREAKPOINTS];
50static db_breakpoint_t		db_next_free_breakpoint = &db_break_table[0];
51static db_breakpoint_t		db_free_breakpoints = 0;
52static db_breakpoint_t		db_breakpoint_list = 0;
53
54static db_breakpoint_t	db_breakpoint_alloc(void);
55static void	db_breakpoint_free(db_breakpoint_t bkpt);
56static void	db_delete_breakpoint(vm_map_t map, db_addr_t addr);
57static db_breakpoint_t	db_find_breakpoint(vm_map_t map, db_addr_t addr);
58static void	db_list_breakpoints(void);
59static void	db_set_breakpoint(vm_map_t map, db_addr_t addr, int count);
60
61static db_breakpoint_t
62db_breakpoint_alloc()
63{
64	register db_breakpoint_t	bkpt;
65
66	if ((bkpt = db_free_breakpoints) != 0) {
67	    db_free_breakpoints = bkpt->link;
68	    return (bkpt);
69	}
70	if (db_next_free_breakpoint == &db_break_table[NBREAKPOINTS]) {
71	    db_printf("All breakpoints used.\n");
72	    return (0);
73	}
74	bkpt = db_next_free_breakpoint;
75	db_next_free_breakpoint++;
76
77	return (bkpt);
78}
79
80static void
81db_breakpoint_free(bkpt)
82	register db_breakpoint_t	bkpt;
83{
84	bkpt->link = db_free_breakpoints;
85	db_free_breakpoints = bkpt;
86}
87
88static void
89db_set_breakpoint(map, addr, count)
90	vm_map_t	map;
91	db_addr_t	addr;
92	int		count;
93{
94	register db_breakpoint_t	bkpt;
95
96	if (db_find_breakpoint(map, addr)) {
97	    db_printf("Already set.\n");
98	    return;
99	}
100
101	bkpt = db_breakpoint_alloc();
102	if (bkpt == 0) {
103	    db_printf("Too many breakpoints.\n");
104	    return;
105	}
106
107	bkpt->map = map;
108	bkpt->address = addr;
109	bkpt->flags = 0;
110	bkpt->init_count = count;
111	bkpt->count = count;
112
113	bkpt->link = db_breakpoint_list;
114	db_breakpoint_list = bkpt;
115}
116
117static void
118db_delete_breakpoint(map, addr)
119	vm_map_t	map;
120	db_addr_t	addr;
121{
122	register db_breakpoint_t	bkpt;
123	register db_breakpoint_t	*prev;
124
125	for (prev = &db_breakpoint_list;
126	     (bkpt = *prev) != 0;
127	     prev = &bkpt->link) {
128	    if (db_map_equal(bkpt->map, map) &&
129		(bkpt->address == addr)) {
130		*prev = bkpt->link;
131		break;
132	    }
133	}
134	if (bkpt == 0) {
135	    db_printf("Not set.\n");
136	    return;
137	}
138
139	db_breakpoint_free(bkpt);
140}
141
142static db_breakpoint_t
143db_find_breakpoint(map, addr)
144	vm_map_t	map;
145	db_addr_t	addr;
146{
147	register db_breakpoint_t	bkpt;
148
149	for (bkpt = db_breakpoint_list;
150	     bkpt != 0;
151	     bkpt = bkpt->link)
152	{
153	    if (db_map_equal(bkpt->map, map) &&
154		(bkpt->address == addr))
155		return (bkpt);
156	}
157	return (0);
158}
159
160db_breakpoint_t
161db_find_breakpoint_here(addr)
162	db_addr_t	addr;
163{
164    return db_find_breakpoint(db_map_addr(addr), addr);
165}
166
167static boolean_t	db_breakpoints_inserted = TRUE;
168
169#ifndef BKPT_WRITE
170#define BKPT_WRITE(addr, storage)				\
171do {								\
172	*storage = db_get_value(addr, BKPT_SIZE, FALSE);	\
173	db_put_value(addr, BKPT_SIZE, BKPT_SET(*storage));	\
174} while (0)
175#endif
176
177#ifndef BKPT_CLEAR
178#define BKPT_CLEAR(addr, storage) \
179	db_put_value(addr, BKPT_SIZE, *storage)
180#endif
181
182void
183db_set_breakpoints()
184{
185	register db_breakpoint_t	bkpt;
186
187	if (!db_breakpoints_inserted) {
188
189		for (bkpt = db_breakpoint_list;
190		     bkpt != 0;
191		     bkpt = bkpt->link)
192			if (db_map_current(bkpt->map)) {
193				BKPT_WRITE(bkpt->address, &bkpt->bkpt_inst);
194			}
195		db_breakpoints_inserted = TRUE;
196	}
197}
198
199void
200db_clear_breakpoints()
201{
202	register db_breakpoint_t	bkpt;
203
204	if (db_breakpoints_inserted) {
205
206		for (bkpt = db_breakpoint_list;
207		     bkpt != 0;
208		     bkpt = bkpt->link)
209			if (db_map_current(bkpt->map)) {
210				BKPT_CLEAR(bkpt->address, &bkpt->bkpt_inst);
211			}
212		db_breakpoints_inserted = FALSE;
213	}
214}
215
216#ifdef SOFTWARE_SSTEP
217/*
218 * Set a temporary breakpoint.
219 * The instruction is changed immediately,
220 * so the breakpoint does not have to be on the breakpoint list.
221 */
222db_breakpoint_t
223db_set_temp_breakpoint(addr)
224	db_addr_t	addr;
225{
226	register db_breakpoint_t	bkpt;
227
228	bkpt = db_breakpoint_alloc();
229	if (bkpt == 0) {
230	    db_printf("Too many breakpoints.\n");
231	    return 0;
232	}
233
234	bkpt->map = NULL;
235	bkpt->address = addr;
236	bkpt->flags = BKPT_TEMP;
237	bkpt->init_count = 1;
238	bkpt->count = 1;
239
240	BKPT_WRITE(bkpt->address, &bkpt->bkpt_inst);
241	return bkpt;
242}
243
244void
245db_delete_temp_breakpoint(bkpt)
246	db_breakpoint_t	bkpt;
247{
248	BKPT_CLEAR(bkpt->address, &bkpt->bkpt_inst);
249	db_breakpoint_free(bkpt);
250}
251#endif /* SOFTWARE_SSTEP */
252
253/*
254 * List breakpoints.
255 */
256static void
257db_list_breakpoints()
258{
259	register db_breakpoint_t	bkpt;
260
261	if (db_breakpoint_list == 0) {
262	    db_printf("No breakpoints set\n");
263	    return;
264	}
265
266	db_printf(" Map      Count    Address\n");
267	for (bkpt = db_breakpoint_list;
268	     bkpt != 0;
269	     bkpt = bkpt->link) {
270	    db_printf("%s%8p %5d    ",
271		      db_map_current(bkpt->map) ? "*" : " ",
272		      (void *)bkpt->map, bkpt->init_count);
273	    db_printsym(bkpt->address, DB_STGY_PROC);
274	    db_printf("\n");
275	}
276}
277
278/* Delete breakpoint */
279/*ARGSUSED*/
280void
281db_delete_cmd(addr, have_addr, count, modif)
282	db_expr_t	addr;
283	boolean_t	have_addr;
284	db_expr_t	count;
285	char *		modif;
286{
287	db_delete_breakpoint(db_map_addr(addr), (db_addr_t)addr);
288}
289
290/* Set breakpoint with skip count */
291/*ARGSUSED*/
292void
293db_breakpoint_cmd(addr, have_addr, count, modif)
294	db_expr_t	addr;
295	boolean_t	have_addr;
296	db_expr_t	count;
297	char *		modif;
298{
299	if (count == -1)
300	    count = 1;
301
302	db_set_breakpoint(db_map_addr(addr), (db_addr_t)addr, count);
303}
304
305/* list breakpoints */
306void
307db_listbreak_cmd(dummy1, dummy2, dummy3, dummy4)
308	db_expr_t	dummy1;
309	boolean_t	dummy2;
310	db_expr_t	dummy3;
311	char *		dummy4;
312{
313	db_list_breakpoints();
314}
315
316/*
317 *	We want ddb to be usable before most of the kernel has been
318 *	initialized.  In particular, current_thread() or kernel_map
319 *	(or both) may be null.
320 */
321
322boolean_t
323db_map_equal(map1, map2)
324	vm_map_t	map1, map2;
325{
326	return ((map1 == map2) ||
327		((map1 == NULL) && (map2 == kernel_map)) ||
328		((map1 == kernel_map) && (map2 == NULL)));
329}
330
331boolean_t
332db_map_current(map)
333	vm_map_t	map;
334{
335#if 0
336	thread_t	thread;
337
338	return ((map == NULL) ||
339		(map == kernel_map) ||
340		(((thread = current_thread()) != NULL) &&
341		 (map == thread->task->map)));
342#else
343	return (1);
344#endif
345}
346
347vm_map_t
348db_map_addr(addr)
349	vm_offset_t addr;
350{
351#if 0
352	thread_t	thread;
353
354	/*
355	 *	We want to return kernel_map for all
356	 *	non-user addresses, even when debugging
357	 *	kernel tasks with their own maps.
358	 */
359
360	if ((VM_MIN_ADDRESS <= addr) &&
361	    (addr < VM_MAX_ADDRESS) &&
362	    ((thread = current_thread()) != NULL))
363	    return thread->task->map;
364	else
365#endif
366	    return kernel_map;
367}
368