db_watch.c revision 1.7 
1/*	$OpenBSD: db_watch.c,v 1.7 2001/12/08 02:24:07 art Exp $ */
2/*	$NetBSD: db_watch.c,v 1.9 1996/03/30 22:30:12 christos Exp $	*/
3
4/*
5 * Mach Operating System
6 * Copyright (c) 1993,1992,1991,1990 Carnegie Mellon University
7 * All Rights Reserved.
8 *
9 * Permission to use, copy, modify and distribute this software and its
10 * documentation is hereby granted, provided that both the copyright
11 * notice and this permission notice appear in all copies of the
12 * software, derivative works or modified versions, and any portions
13 * thereof, and that both notices appear in supporting documentation.
14 *
15 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
16 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
17 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
18 *
19 * Carnegie Mellon requests users of this software to return to
20 *
21 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
22 *  School of Computer Science
23 *  Carnegie Mellon University
24 *  Pittsburgh PA 15213-3890
25 *
26 * any improvements or extensions that they make and grant Carnegie Mellon
27 * the rights to redistribute these changes.
28 *
29 * 	Author: Richard P. Draves, Carnegie Mellon University
30 *	Date:	10/90
31 */
32
33#include <sys/param.h>
34#include <sys/proc.h>
35
36#include <machine/db_machdep.h>
37
38#include <ddb/db_break.h>
39#include <ddb/db_watch.h>
40#include <ddb/db_lex.h>
41#include <ddb/db_access.h>
42#include <ddb/db_run.h>
43#include <ddb/db_sym.h>
44#include <ddb/db_output.h>
45#include <ddb/db_command.h>
46#include <ddb/db_extern.h>
47
48/*
49 * Watchpoints.
50 */
51
52boolean_t	db_watchpoints_inserted = TRUE;
53
54#define	NWATCHPOINTS	100
55struct db_watchpoint	db_watch_table[NWATCHPOINTS];
56db_watchpoint_t		db_next_free_watchpoint = &db_watch_table[0];
57db_watchpoint_t		db_free_watchpoints = 0;
58db_watchpoint_t		db_watchpoint_list = 0;
59
60db_watchpoint_t
61db_watchpoint_alloc()
62{
63	register db_watchpoint_t	watch;
64
65	if ((watch = db_free_watchpoints) != 0) {
66	    db_free_watchpoints = watch->link;
67	    return (watch);
68	}
69	if (db_next_free_watchpoint == &db_watch_table[NWATCHPOINTS]) {
70	    db_printf("All watchpoints used.\n");
71	    return (0);
72	}
73	watch = db_next_free_watchpoint;
74	db_next_free_watchpoint++;
75
76	return (watch);
77}
78
79void
80db_watchpoint_free(watch)
81	register db_watchpoint_t	watch;
82{
83	watch->link = db_free_watchpoints;
84	db_free_watchpoints = watch;
85}
86
87void
88db_set_watchpoint(map, addr, size)
89	struct vm_map	*map;
90	db_addr_t	addr;
91	vsize_t 	size;
92{
93	register db_watchpoint_t	watch;
94
95	if (map == NULL) {
96	    db_printf("No map.\n");
97	    return;
98	}
99
100	/*
101	 *	Should we do anything fancy with overlapping regions?
102	 */
103
104	for (watch = db_watchpoint_list;
105	     watch != 0;
106	     watch = watch->link)
107	    if (db_map_equal(watch->map, map) &&
108		(watch->loaddr == addr) &&
109		(watch->hiaddr == addr+size)) {
110		db_printf("Already set.\n");
111		return;
112	    }
113
114	watch = db_watchpoint_alloc();
115	if (watch == 0) {
116	    db_printf("Too many watchpoints.\n");
117	    return;
118	}
119
120	watch->map = map;
121	watch->loaddr = addr;
122	watch->hiaddr = addr+size;
123
124	watch->link = db_watchpoint_list;
125	db_watchpoint_list = watch;
126
127	db_watchpoints_inserted = FALSE;
128}
129
130void
131db_delete_watchpoint(map, addr)
132	struct vm_map	*map;
133	db_addr_t	addr;
134{
135	register db_watchpoint_t	watch;
136	register 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()
154{
155	register 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;
164	     watch != 0;
165	     watch = watch->link)
166	    db_printf("%s%p  %8lx  %lx\n",
167		      db_map_current(watch->map) ? "*" : " ",
168		      watch->map, watch->loaddr,
169		      watch->hiaddr - watch->loaddr);
170}
171
172/* Delete watchpoint */
173/*ARGSUSED*/
174void
175db_deletewatch_cmd(addr, have_addr, count, modif)
176	db_expr_t	addr;
177	int		have_addr;
178	db_expr_t	count;
179	char *		modif;
180{
181	db_delete_watchpoint(db_map_addr(addr), addr);
182}
183
184/* Set watchpoint */
185/*ARGSUSED*/
186void
187db_watchpoint_cmd(addr, have_addr, count, modif)
188	db_expr_t	addr;
189	int		have_addr;
190	db_expr_t	count;
191	char *		modif;
192{
193	vsize_t 	size;
194	db_expr_t	value;
195
196	if (db_expression(&value))
197	    size = (vsize_t) value;
198	else
199	    size = 4;
200	db_skip_to_eol();
201
202	db_set_watchpoint(db_map_addr(addr), addr, size);
203}
204
205/* list watchpoints */
206/*ARGSUSED*/
207void
208db_listwatch_cmd(addr, have_addr, count, modif)
209	db_expr_t	addr;
210	int		have_addr;
211	db_expr_t	count;
212	char *		modif;
213{
214	db_list_watchpoints();
215}
216
217void
218db_set_watchpoints()
219{
220	register db_watchpoint_t	watch;
221
222	if (!db_watchpoints_inserted) {
223	    for (watch = db_watchpoint_list;
224	         watch != 0;
225	         watch = watch->link)
226		pmap_protect(watch->map->pmap,
227			     trunc_page(watch->loaddr),
228			     round_page(watch->hiaddr),
229			     VM_PROT_READ);
230	    pmap_update(watch->map->pmap);
231	    db_watchpoints_inserted = TRUE;
232	}
233}
234
235void
236db_clear_watchpoints()
237{
238	db_watchpoints_inserted = FALSE;
239}
240
241boolean_t
242db_find_watchpoint(map, addr, regs)
243	struct vm_map	*map;
244	db_addr_t	addr;
245	db_regs_t	*regs;
246{
247	register db_watchpoint_t watch;
248	db_watchpoint_t found = 0;
249
250	for (watch = db_watchpoint_list;
251	     watch != 0;
252	     watch = watch->link)
253	    if (db_map_equal(watch->map, map)) {
254		if ((watch->loaddr <= addr) &&
255		    (addr < watch->hiaddr))
256		    return (TRUE);
257		else if ((trunc_page(watch->loaddr) <= addr) &&
258			 (addr < round_page(watch->hiaddr)))
259		    found = watch;
260	    }
261
262	/*
263	 *	We didn't hit exactly on a watchpoint, but we are
264	 *	in a protected region.  We want to single-step
265	 *	and then re-protect.
266	 */
267
268	if (found) {
269	    db_watchpoints_inserted = FALSE;
270	    db_single_step(regs);
271	}
272
273	return (FALSE);
274}
275