FreeBSD/Linux Kernel Cross Reference
sys/ddb/db_watch.c
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 * $FreeBSD: src/sys/ddb/db_watch.c,v 1.11.4.1 1999/09/05 08:08:55 peter Exp $
27 */
28
29 /*
30 * Author: Richard P. Draves, Carnegie Mellon University
31 * Date: 10/90
32 */
33
34 #include <sys/param.h>
35 #include <sys/systm.h>
36
37 #include <vm/vm.h>
38 #include <vm/lock.h>
39 #include <vm/pmap.h>
40 #include <vm/vm_map.h>
41 #include <vm/vm_prot.h>
42
43 #include <ddb/ddb.h>
44 #include <ddb/db_lex.h>
45 #include <ddb/db_watch.h>
46 #include <ddb/db_access.h>
47 #include <ddb/db_sym.h>
48
49 /*
50 * Watchpoints.
51 */
52
53 static boolean_t db_watchpoints_inserted = TRUE;
54
55 #define NWATCHPOINTS 100
56 static struct db_watchpoint db_watch_table[NWATCHPOINTS];
57 static db_watchpoint_t db_next_free_watchpoint = &db_watch_table[0];
58 static db_watchpoint_t db_free_watchpoints = 0;
59 static db_watchpoint_t db_watchpoint_list = 0;
60
61 static db_watchpoint_t db_watchpoint_alloc __P((void));
62 static void db_watchpoint_free __P((db_watchpoint_t watch));
63 static void db_delete_watchpoint __P((vm_map_t map,
64 db_addr_t addr));
65 #ifdef notused
66 static boolean_t db_find_watchpoint __P((vm_map_t map, db_addr_t addr,
67 db_regs_t *regs));
68 #endif
69 static void db_list_watchpoints __P((void));
70 static void db_set_watchpoint __P((vm_map_t map, db_addr_t addr,
71 vm_size_t size));
72
73
74 db_watchpoint_t
75 db_watchpoint_alloc()
76 {
77 register db_watchpoint_t watch;
78
79 if ((watch = db_free_watchpoints) != 0) {
80 db_free_watchpoints = watch->link;
81 return (watch);
82 }
83 if (db_next_free_watchpoint == &db_watch_table[NWATCHPOINTS]) {
84 db_printf("All watchpoints used.\n");
85 return (0);
86 }
87 watch = db_next_free_watchpoint;
88 db_next_free_watchpoint++;
89
90 return (watch);
91 }
92
93 void
94 db_watchpoint_free(watch)
95 register db_watchpoint_t watch;
96 {
97 watch->link = db_free_watchpoints;
98 db_free_watchpoints = watch;
99 }
100
101 static void
102 db_set_watchpoint(map, addr, size)
103 vm_map_t map;
104 db_addr_t addr;
105 vm_size_t size;
106 {
107 register db_watchpoint_t watch;
108
109 if (map == NULL) {
110 db_printf("No map.\n");
111 return;
112 }
113
114 /*
115 * Should we do anything fancy with overlapping regions?
116 */
117
118 for (watch = db_watchpoint_list;
119 watch != 0;
120 watch = watch->link)
121 if (db_map_equal(watch->map, map) &&
122 (watch->loaddr == addr) &&
123 (watch->hiaddr == addr+size)) {
124 db_printf("Already set.\n");
125 return;
126 }
127
128 watch = db_watchpoint_alloc();
129 if (watch == 0) {
130 db_printf("Too many watchpoints.\n");
131 return;
132 }
133
134 watch->map = map;
135 watch->loaddr = addr;
136 watch->hiaddr = addr+size;
137
138 watch->link = db_watchpoint_list;
139 db_watchpoint_list = watch;
140
141 db_watchpoints_inserted = FALSE;
142 }
143
144 static void
145 db_delete_watchpoint(map, addr)
146 vm_map_t map;
147 db_addr_t addr;
148 {
149 register db_watchpoint_t watch;
150 register db_watchpoint_t *prev;
151
152 for (prev = &db_watchpoint_list;
153 (watch = *prev) != 0;
154 prev = &watch->link)
155 if (db_map_equal(watch->map, map) &&
156 (watch->loaddr <= addr) &&
157 (addr < watch->hiaddr)) {
158 *prev = watch->link;
159 db_watchpoint_free(watch);
160 return;
161 }
162
163 db_printf("Not set.\n");
164 }
165
166 static void
167 db_list_watchpoints()
168 {
169 register db_watchpoint_t watch;
170
171 if (db_watchpoint_list == 0) {
172 db_printf("No watchpoints set\n");
173 return;
174 }
175
176 db_printf(" Map Address Size\n");
177 for (watch = db_watchpoint_list;
178 watch != 0;
179 watch = watch->link)
180 db_printf("%s%8x %8x %x\n",
181 db_map_current(watch->map) ? "*" : " ",
182 watch->map, watch->loaddr,
183 watch->hiaddr - watch->loaddr);
184 }
185
186 /* Delete watchpoint */
187 /*ARGSUSED*/
188 void
189 db_deletewatch_cmd(addr, have_addr, count, modif)
190 db_expr_t addr;
191 boolean_t have_addr;
192 db_expr_t count;
193 char * modif;
194 {
195 db_delete_watchpoint(db_map_addr(addr), addr);
196 }
197
198 /* Set watchpoint */
199 /*ARGSUSED*/
200 void
201 db_watchpoint_cmd(addr, have_addr, count, modif)
202 db_expr_t addr;
203 boolean_t have_addr;
204 db_expr_t count;
205 char * modif;
206 {
207 vm_size_t size;
208 db_expr_t value;
209
210 if (db_expression(&value))
211 size = (vm_size_t) value;
212 else
213 size = 4;
214 db_skip_to_eol();
215
216 db_set_watchpoint(db_map_addr(addr), addr, size);
217 }
218
219 /* list watchpoints */
220 void
221 db_listwatch_cmd(dummy1, dummy2, dummy3, dummy4)
222 db_expr_t dummy1;
223 boolean_t dummy2;
224 db_expr_t dummy3;
225 char * dummy4;
226 {
227 db_list_watchpoints();
228 }
229
230 void
231 db_set_watchpoints()
232 {
233 register db_watchpoint_t watch;
234
235 if (!db_watchpoints_inserted) {
236 for (watch = db_watchpoint_list;
237 watch != 0;
238 watch = watch->link)
239 pmap_protect(watch->map->pmap,
240 trunc_page(watch->loaddr),
241 round_page(watch->hiaddr),
242 VM_PROT_READ);
243
244 db_watchpoints_inserted = TRUE;
245 }
246 }
247
248 void
249 db_clear_watchpoints()
250 {
251 db_watchpoints_inserted = FALSE;
252 }
253
254 #ifdef notused
255 static boolean_t
256 db_find_watchpoint(map, addr, regs)
257 vm_map_t map;
258 db_addr_t addr;
259 db_regs_t *regs;
260 {
261 register db_watchpoint_t watch;
262 db_watchpoint_t found = 0;
263
264 for (watch = db_watchpoint_list;
265 watch != 0;
266 watch = watch->link)
267 if (db_map_equal(watch->map, map)) {
268 if ((watch->loaddr <= addr) &&
269 (addr < watch->hiaddr))
270 return (TRUE);
271 else if ((trunc_page(watch->loaddr) <= addr) &&
272 (addr < round_page(watch->hiaddr)))
273 found = watch;
274 }
275
276 /*
277 * We didn't hit exactly on a watchpoint, but we are
278 * in a protected region. We want to single-step
279 * and then re-protect.
280 */
281
282 if (found) {
283 db_watchpoints_inserted = FALSE;
284 db_single_step(regs);
285 }
286
287 return (FALSE);
288 }
289 #endif
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