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 /*
27 * Author: Richard P. Draves, Carnegie Mellon University
28 * Date: 10/90
29 */
30
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD: releng/6.0/sys/ddb/db_watch.c 139747 2005-01-06 01:34:41Z imp $");
33
34 #include <sys/param.h>
35 #include <sys/kernel.h>
36 #include <sys/lock.h>
37 #include <sys/proc.h>
38
39 #include <vm/vm.h>
40 #include <vm/pmap.h>
41 #include <vm/vm_map.h>
42
43 #include <ddb/ddb.h>
44 #include <ddb/db_watch.h>
45
46 /*
47 * Watchpoints.
48 */
49
50 static boolean_t db_watchpoints_inserted = TRUE;
51
52 #define NWATCHPOINTS 100
53 static struct db_watchpoint db_watch_table[NWATCHPOINTS];
54 static db_watchpoint_t db_next_free_watchpoint = &db_watch_table[0];
55 static db_watchpoint_t db_free_watchpoints = 0;
56 static db_watchpoint_t db_watchpoint_list = 0;
57
58 static db_watchpoint_t db_watchpoint_alloc(void);
59 static void db_watchpoint_free(db_watchpoint_t watch);
60 static void db_delete_watchpoint(vm_map_t map, db_addr_t addr);
61 #ifdef notused
62 static boolean_t db_find_watchpoint(vm_map_t map, db_addr_t addr,
63 db_regs_t *regs);
64 #endif
65 static void db_list_watchpoints(void);
66 static void db_set_watchpoint(vm_map_t map, db_addr_t addr,
67 vm_size_t size);
68
69 int db_md_set_watchpoint(db_expr_t addr, db_expr_t size);
70 int db_md_clr_watchpoint(db_expr_t addr, db_expr_t size);
71 void db_md_list_watchpoints(void);
72
73
74 static 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 static 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%8p %8lx %lx\n",
181 db_map_current(watch->map) ? "*" : " ",
182 (void *)watch->map, (long)watch->loaddr,
183 (long)watch->hiaddr - (long)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 /*
220 * At least one non-optional show-command must be implemented using
221 * DB_SHOW_COMMAND() so that db_show_cmd_set gets created. Here is one.
222 */
223 DB_SHOW_COMMAND(watches, db_listwatch_cmd)
224 {
225 db_list_watchpoints();
226 db_md_list_watchpoints();
227 }
228
229 void
230 db_set_watchpoints()
231 {
232 register db_watchpoint_t watch;
233
234 if (!db_watchpoints_inserted) {
235 for (watch = db_watchpoint_list;
236 watch != 0;
237 watch = watch->link)
238 pmap_protect(watch->map->pmap,
239 trunc_page(watch->loaddr),
240 round_page(watch->hiaddr),
241 VM_PROT_READ);
242
243 db_watchpoints_inserted = TRUE;
244 }
245 }
246
247 void
248 db_clear_watchpoints()
249 {
250 db_watchpoints_inserted = FALSE;
251 }
252
253 #ifdef notused
254 static boolean_t
255 db_find_watchpoint(map, addr, regs)
256 vm_map_t map;
257 db_addr_t addr;
258 db_regs_t *regs;
259 {
260 register db_watchpoint_t watch;
261 db_watchpoint_t found = 0;
262
263 for (watch = db_watchpoint_list;
264 watch != 0;
265 watch = watch->link)
266 if (db_map_equal(watch->map, map)) {
267 if ((watch->loaddr <= addr) &&
268 (addr < watch->hiaddr))
269 return (TRUE);
270 else if ((trunc_page(watch->loaddr) <= addr) &&
271 (addr < round_page(watch->hiaddr)))
272 found = watch;
273 }
274
275 /*
276 * We didn't hit exactly on a watchpoint, but we are
277 * in a protected region. We want to single-step
278 * and then re-protect.
279 */
280
281 if (found) {
282 db_watchpoints_inserted = FALSE;
283 db_single_step(regs);
284 }
285
286 return (FALSE);
287 }
288 #endif
289
290
291
292 /* Delete hardware watchpoint */
293 /*ARGSUSED*/
294 void
295 db_deletehwatch_cmd(addr, have_addr, count, modif)
296 db_expr_t addr;
297 boolean_t have_addr;
298 db_expr_t count;
299 char * modif;
300 {
301 int rc;
302
303 if (count < 0)
304 count = 4;
305
306 rc = db_md_clr_watchpoint(addr, count);
307 if (rc < 0)
308 db_printf("hardware watchpoint could not be deleted\n");
309 }
310
311 /* Set hardware watchpoint */
312 /*ARGSUSED*/
313 void
314 db_hwatchpoint_cmd(addr, have_addr, count, modif)
315 db_expr_t addr;
316 boolean_t have_addr;
317 db_expr_t count;
318 char * modif;
319 {
320 int rc;
321
322 if (count < 0)
323 count = 4;
324
325 rc = db_md_set_watchpoint(addr, count);
326 if (rc < 0)
327 db_printf("hardware watchpoint could not be set\n");
328 }
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