1/*	$NetBSD: db_watch.c,v 1.26 2007/02/22 04:38:06 matt Exp $	*/
2
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 "AS IS"
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 * 	Author: Richard P. Draves, Carnegie Mellon University
29 *	Date:	10/90
30 */
31
32#include <sys/cdefs.h>
33__KERNEL_RCSID(0, "$NetBSD: db_watch.c,v 1.26 2007/02/22 04:38:06 matt Exp $");
34
35#include <sys/param.h>
36#include <sys/proc.h>
37
38#include <machine/db_machdep.h>
39
40#include <ddb/db_break.h>
41#include <ddb/db_watch.h>
42#include <ddb/db_lex.h>
43#include <ddb/db_access.h>
44#include <ddb/db_run.h>
45#include <ddb/db_sym.h>
46#include <ddb/db_output.h>
47#include <ddb/db_command.h>
48#include <ddb/db_extern.h>
49
50/*
51 * Watchpoints.
52 */
53
54static bool			db_watchpoints_inserted = true;
55
56#define	NWATCHPOINTS	100
57static struct db_watchpoint	db_watch_table[NWATCHPOINTS];
58static db_watchpoint_t		db_next_free_watchpoint = &db_watch_table[0];
59static db_watchpoint_t		db_free_watchpoints = 0;
60static db_watchpoint_t		db_watchpoint_list = 0;
61
62static void		db_delete_watchpoint(struct vm_map *, db_addr_t);
63static void		db_list_watchpoints(void);
64static void		db_set_watchpoint(struct vm_map *, db_addr_t, vsize_t);
65static db_watchpoint_t	db_watchpoint_alloc(void);
66static void		db_watchpoint_free(db_watchpoint_t);
67
68db_watchpoint_t
69db_watchpoint_alloc(void)
70{
71	db_watchpoint_t	watch;
72
73	if ((watch = db_free_watchpoints) != 0) {
74		db_free_watchpoints = watch->link;
75		return (watch);
76	}
77	if (db_next_free_watchpoint == &db_watch_table[NWATCHPOINTS]) {
78		db_printf("All watchpoints used.\n");
79		return (0);
80	}
81	watch = db_next_free_watchpoint;
82	db_next_free_watchpoint++;
83
84	return (watch);
85}
86
87void
88db_watchpoint_free(db_watchpoint_t watch)
89{
90	watch->link = db_free_watchpoints;
91	db_free_watchpoints = watch;
92}
93
94void
95db_set_watchpoint(struct vm_map *map, db_addr_t addr, vsize_t size)
96{
97	db_watchpoint_t	watch;
98
99	if (map == NULL) {
100		db_printf("No map.\n");
101		return;
102	}
103
104	/*
105	 *	Should we do anything fancy with overlapping regions?
106	 */
107
108	for (watch = db_watchpoint_list; watch != 0; watch = watch->link)
109		if (db_map_equal(watch->map, map) &&
110		    (watch->loaddr == addr) &&
111		    (watch->hiaddr == addr+size)) {
112			db_printf("Already set.\n");
113			return;
114		}
115
116	watch = db_watchpoint_alloc();
117	if (watch == 0) {
118		db_printf("Too many watchpoints.\n");
119		return;
120	}
121
122	watch->map = map;
123	watch->loaddr = addr;
124	watch->hiaddr = addr+size;
125
126	watch->link = db_watchpoint_list;
127	db_watchpoint_list = watch;
128
129	db_watchpoints_inserted = false;
130}
131
132static void
133db_delete_watchpoint(struct vm_map *map, db_addr_t addr)
134{
135	db_watchpoint_t	watch;
136	db_watchpoint_t	*prev;
137
138	for (prev = &db_watchpoint_list;
139	     (watch = *prev) != 0;
140	     prev = &watch->link)
141		if (db_map_equal(watch->map, map) &&
142		    (watch->loaddr <= addr) &&
143		    (addr < watch->hiaddr)) {
144			*prev = watch->link;
145			db_watchpoint_free(watch);
146			return;
147		}
148
149	db_printf("Not set.\n");
150}
151
152void
153db_list_watchpoints(void)
154{
155	db_watchpoint_t	watch;
156
157	if (db_watchpoint_list == 0) {
158		db_printf("No watchpoints set\n");
159		return;
160	}
161
162	db_printf(" Map        Address  Size\n");
163	for (watch = db_watchpoint_list; watch != 0; watch = watch->link)
164		db_printf("%s%p  %8lx  %lx\n",
165		    db_map_current(watch->map) ? "*" : " ",
166		    watch->map, (long)watch->loaddr,
167		    (long)(watch->hiaddr - watch->loaddr));
168}
169
170/* Delete watchpoint */
171/*ARGSUSED*/
172void
173db_deletewatch_cmd(db_expr_t addr, bool have_addr,
174    db_expr_t count, const char *modif)
175{
176
177	db_delete_watchpoint(db_map_addr(addr), addr);
178}
179
180/* Set watchpoint */
181/*ARGSUSED*/
182void
183db_watchpoint_cmd(db_expr_t addr, bool have_addr,
184    db_expr_t count, const char *modif)
185{
186	vsize_t size;
187	db_expr_t value;
188
189	if (db_expression(&value))
190		size = (vsize_t) value;
191	else
192		size = 4;
193	db_skip_to_eol();
194
195	db_set_watchpoint(db_map_addr(addr), addr, size);
196}
197
198/* list watchpoints */
199/*ARGSUSED*/
200void
201db_listwatch_cmd(db_expr_t addr, bool have_addr,
202    db_expr_t count, const char *modif)
203{
204
205	db_list_watchpoints();
206}
207
208void
209db_set_watchpoints(void)
210{
211	db_watchpoint_t	watch;
212
213	if (!db_watchpoints_inserted) {
214		for (watch = db_watchpoint_list;
215		     watch != 0;
216		     watch = watch->link) {
217			pmap_protect(watch->map->pmap,
218			    trunc_page(watch->loaddr),
219			    round_page(watch->hiaddr),
220			    VM_PROT_READ);
221			pmap_update(watch->map->pmap);
222		}
223
224		db_watchpoints_inserted = true;
225	}
226}
227
228void
229db_clear_watchpoints(void)
230{
231
232	db_watchpoints_inserted = false;
233}
234