summaryrefslogtreecommitdiffstats
path: root/sys/ddb/db_watch.c
blob: 127e3bb4203df54cbf1304ab96bdaed701929bfb (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
/*
 * 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
 * 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 the
 * rights to redistribute these changes.
 *
 * $FreeBSD$
 */

/*
 * 	Author: Richard P. Draves, Carnegie Mellon University
 *	Date:	10/90
 */

#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/proc.h>

#include <vm/vm.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>

#include <ddb/ddb.h>
#include <ddb/db_watch.h>

/*
 * Watchpoints.
 */

static boolean_t	db_watchpoints_inserted = TRUE;

#define	NWATCHPOINTS	100
static struct db_watchpoint	db_watch_table[NWATCHPOINTS];
static db_watchpoint_t	db_next_free_watchpoint = &db_watch_table[0];
static db_watchpoint_t	db_free_watchpoints = 0;
static db_watchpoint_t	db_watchpoint_list = 0;

static db_watchpoint_t	db_watchpoint_alloc(void);
static void		db_watchpoint_free(db_watchpoint_t watch);
static void		db_delete_watchpoint(vm_map_t map, db_addr_t addr);
#ifdef notused
static boolean_t	db_find_watchpoint(vm_map_t map, db_addr_t addr,
					db_regs_t *regs);
#endif
static void		db_list_watchpoints(void);
static void		db_set_watchpoint(vm_map_t map, db_addr_t addr,
				       vm_size_t size);

int  db_md_set_watchpoint(db_expr_t addr, db_expr_t size);
int  db_md_clr_watchpoint(db_expr_t addr, db_expr_t size);
void db_md_list_watchpoints(void);


static db_watchpoint_t
db_watchpoint_alloc()
{
	register db_watchpoint_t	watch;

	if ((watch = db_free_watchpoints) != 0) {
	    db_free_watchpoints = watch->link;
	    return (watch);
	}
	if (db_next_free_watchpoint == &db_watch_table[NWATCHPOINTS]) {
	    db_printf("All watchpoints used.\n");
	    return (0);
	}
	watch = db_next_free_watchpoint;
	db_next_free_watchpoint++;

	return (watch);
}

static void
db_watchpoint_free(watch)
	register db_watchpoint_t	watch;
{
	watch->link = db_free_watchpoints;
	db_free_watchpoints = watch;
}

static void
db_set_watchpoint(map, addr, size)
	vm_map_t	map;
	db_addr_t	addr;
	vm_size_t	size;
{
	register db_watchpoint_t	watch;

	if (map == NULL) {
	    db_printf("No map.\n");
	    return;
	}

	/*
	 *	Should we do anything fancy with overlapping regions?
	 */

	for (watch = db_watchpoint_list;
	     watch != 0;
	     watch = watch->link)
	    if (db_map_equal(watch->map, map) &&
		(watch->loaddr == addr) &&
		(watch->hiaddr == addr+size)) {
		db_printf("Already set.\n");
		return;
	    }

	watch = db_watchpoint_alloc();
	if (watch == 0) {
	    db_printf("Too many watchpoints.\n");
	    return;
	}

	watch->map = map;
	watch->loaddr = addr;
	watch->hiaddr = addr+size;

	watch->link = db_watchpoint_list;
	db_watchpoint_list = watch;

	db_watchpoints_inserted = FALSE;
}

static void
db_delete_watchpoint(map, addr)
	vm_map_t	map;
	db_addr_t	addr;
{
	register db_watchpoint_t	watch;
	register db_watchpoint_t	*prev;

	for (prev = &db_watchpoint_list;
	     (watch = *prev) != 0;
	     prev = &watch->link)
	    if (db_map_equal(watch->map, map) &&
		(watch->loaddr <= addr) &&
		(addr < watch->hiaddr)) {
		*prev = watch->link;
		db_watchpoint_free(watch);
		return;
	    }

	db_printf("Not set.\n");
}

static void
db_list_watchpoints()
{
	register db_watchpoint_t	watch;

	if (db_watchpoint_list == 0) {
	    db_printf("No watchpoints set\n");
	    return;
	}

	db_printf(" Map        Address  Size\n");
	for (watch = db_watchpoint_list;
	     watch != 0;
	     watch = watch->link)
	    db_printf("%s%8p  %8lx  %lx\n",
		      db_map_current(watch->map) ? "*" : " ",
		      (void *)watch->map, (long)watch->loaddr,
		      (long)watch->hiaddr - (long)watch->loaddr);
}

/* Delete watchpoint */
/*ARGSUSED*/
void
db_deletewatch_cmd(addr, have_addr, count, modif)
	db_expr_t	addr;
	boolean_t	have_addr;
	db_expr_t	count;
	char *		modif;
{
	db_delete_watchpoint(db_map_addr(addr), addr);
}

/* Set watchpoint */
/*ARGSUSED*/
void
db_watchpoint_cmd(addr, have_addr, count, modif)
	db_expr_t	addr;
	boolean_t	have_addr;
	db_expr_t	count;
	char *		modif;
{
	vm_size_t	size;
	db_expr_t	value;

	if (db_expression(&value))
	    size = (vm_size_t) value;
	else
	    size = 4;
	db_skip_to_eol();

	db_set_watchpoint(db_map_addr(addr), addr, size);
}

/*
 * At least one non-optional show-command must be implemented using
 * DB_SHOW_COMMAND() so that db_show_cmd_set gets created.  Here is one.
 */
DB_SHOW_COMMAND(watches, db_listwatch_cmd)
{
	db_list_watchpoints();
	db_md_list_watchpoints();
}

void
db_set_watchpoints()
{
	register db_watchpoint_t	watch;

	if (!db_watchpoints_inserted) {
	    for (watch = db_watchpoint_list;
	         watch != 0;
	         watch = watch->link)
		pmap_protect(watch->map->pmap,
			     trunc_page(watch->loaddr),
			     round_page(watch->hiaddr),
			     VM_PROT_READ);

	    db_watchpoints_inserted = TRUE;
	}
}

void
db_clear_watchpoints()
{
	db_watchpoints_inserted = FALSE;
}

#ifdef notused
static boolean_t
db_find_watchpoint(map, addr, regs)
	vm_map_t	map;
	db_addr_t	addr;
	db_regs_t	*regs;
{
	register db_watchpoint_t watch;
	db_watchpoint_t found = 0;

	for (watch = db_watchpoint_list;
	     watch != 0;
	     watch = watch->link)
	    if (db_map_equal(watch->map, map)) {
		if ((watch->loaddr <= addr) &&
		    (addr < watch->hiaddr))
		    return (TRUE);
		else if ((trunc_page(watch->loaddr) <= addr) &&
			 (addr < round_page(watch->hiaddr)))
		    found = watch;
	    }

	/*
	 *	We didn't hit exactly on a watchpoint, but we are
	 *	in a protected region.  We want to single-step
	 *	and then re-protect.
	 */

	if (found) {
	    db_watchpoints_inserted = FALSE;
	    db_single_step(regs);
	}

	return (FALSE);
}
#endif



/* Delete hardware watchpoint */
/*ARGSUSED*/
void
db_deletehwatch_cmd(addr, have_addr, count, modif)
	db_expr_t	addr;
	boolean_t	have_addr;
	db_expr_t	count;
	char *		modif;
{
	int rc;

        if (count < 0)
                count = 4;

	rc = db_md_clr_watchpoint(addr, count);
	if (rc < 0)
		db_printf("hardware watchpoint could not be deleted\n");
}

/* Set hardware watchpoint */
/*ARGSUSED*/
void
db_hwatchpoint_cmd(addr, have_addr, count, modif)
	db_expr_t	addr;
	boolean_t	have_addr;
	db_expr_t	count;
	char *		modif;
{
	int rc;

        if (count < 0)
                count = 4;

	rc = db_md_set_watchpoint(addr, count);
	if (rc < 0)
		db_printf("hardware watchpoint could not be set\n");
}
OpenPOWER on IntegriCloud