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: src/sys/ddb/db_watch.c,v 1.28 2006/11/17 16:41:56 jhb Exp $");
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 static db_watchpoint_t
70 db_watchpoint_alloc()
71 {
72 register db_watchpoint_t watch;
73
74 if ((watch = db_free_watchpoints) != 0) {
75 db_free_watchpoints = watch->link;
76 return (watch);
77 }
78 if (db_next_free_watchpoint == &db_watch_table[NWATCHPOINTS]) {
79 db_printf("All watchpoints used.\n");
80 return (0);
81 }
82 watch = db_next_free_watchpoint;
83 db_next_free_watchpoint++;
84
85 return (watch);
86 }
87
88 static void
89 db_watchpoint_free(watch)
90 register db_watchpoint_t watch;
91 {
92 watch->link = db_free_watchpoints;
93 db_free_watchpoints = watch;
94 }
95
96 static void
97 db_set_watchpoint(map, addr, size)
98 vm_map_t map;
99 db_addr_t addr;
100 vm_size_t size;
101 {
102 register db_watchpoint_t watch;
103
104 if (map == NULL) {
105 db_printf("No map.\n");
106 return;
107 }
108
109 /*
110 * Should we do anything fancy with overlapping regions?
111 */
112
113 for (watch = db_watchpoint_list;
114 watch != 0;
115 watch = watch->link)
116 if (db_map_equal(watch->map, map) &&
117 (watch->loaddr == addr) &&
118 (watch->hiaddr == addr+size)) {
119 db_printf("Already set.\n");
120 return;
121 }
122
123 watch = db_watchpoint_alloc();
124 if (watch == 0) {
125 db_printf("Too many watchpoints.\n");
126 return;
127 }
128
129 watch->map = map;
130 watch->loaddr = addr;
131 watch->hiaddr = addr+size;
132
133 watch->link = db_watchpoint_list;
134 db_watchpoint_list = watch;
135
136 db_watchpoints_inserted = FALSE;
137 }
138
139 static void
140 db_delete_watchpoint(map, addr)
141 vm_map_t map;
142 db_addr_t addr;
143 {
144 register db_watchpoint_t watch;
145 register db_watchpoint_t *prev;
146
147 for (prev = &db_watchpoint_list;
148 (watch = *prev) != 0;
149 prev = &watch->link)
150 if (db_map_equal(watch->map, map) &&
151 (watch->loaddr <= addr) &&
152 (addr < watch->hiaddr)) {
153 *prev = watch->link;
154 db_watchpoint_free(watch);
155 return;
156 }
157
158 db_printf("Not set.\n");
159 }
160
161 static void
162 db_list_watchpoints()
163 {
164 register db_watchpoint_t watch;
165
166 if (db_watchpoint_list == 0) {
167 db_printf("No watchpoints set\n");
168 return;
169 }
170
171 #ifdef __LP64__
172 db_printf(" Map Address Size\n");
173 #else
174 db_printf(" Map Address Size\n");
175 #endif
176 for (watch = db_watchpoint_list;
177 watch != 0;
178 watch = watch->link)
179 #ifdef __LP64__
180 db_printf("%s%16p %16lx %lx\n",
181 #else
182 db_printf("%s%8p %8lx %lx\n",
183 #endif
184 db_map_current(watch->map) ? "*" : " ",
185 (void *)watch->map, (long)watch->loaddr,
186 (long)watch->hiaddr - (long)watch->loaddr);
187 }
188
189 /* Delete watchpoint */
190 /*ARGSUSED*/
191 void
192 db_deletewatch_cmd(addr, have_addr, count, modif)
193 db_expr_t addr;
194 boolean_t have_addr;
195 db_expr_t count;
196 char * modif;
197 {
198 db_delete_watchpoint(db_map_addr(addr), addr);
199 }
200
201 /* Set watchpoint */
202 /*ARGSUSED*/
203 void
204 db_watchpoint_cmd(addr, have_addr, count, modif)
205 db_expr_t addr;
206 boolean_t have_addr;
207 db_expr_t count;
208 char * modif;
209 {
210 vm_size_t size;
211 db_expr_t value;
212
213 if (db_expression(&value))
214 size = (vm_size_t) value;
215 else
216 size = 4;
217 db_skip_to_eol();
218
219 db_set_watchpoint(db_map_addr(addr), addr, size);
220 }
221
222 /*
223 * At least one non-optional show-command must be implemented using
224 * DB_SHOW_COMMAND() so that db_show_cmd_set gets created. Here is one.
225 */
226 DB_SHOW_COMMAND(watches, db_listwatch_cmd)
227 {
228 db_list_watchpoints();
229 db_md_list_watchpoints();
230 }
231
232 void
233 db_set_watchpoints()
234 {
235 register db_watchpoint_t watch;
236
237 if (!db_watchpoints_inserted) {
238 for (watch = db_watchpoint_list;
239 watch != 0;
240 watch = watch->link)
241 pmap_protect(watch->map->pmap,
242 trunc_page(watch->loaddr),
243 round_page(watch->hiaddr),
244 VM_PROT_READ);
245
246 db_watchpoints_inserted = TRUE;
247 }
248 }
249
250 void
251 db_clear_watchpoints()
252 {
253 db_watchpoints_inserted = FALSE;
254 }
255
256 #ifdef notused
257 static boolean_t
258 db_find_watchpoint(map, addr, regs)
259 vm_map_t map;
260 db_addr_t addr;
261 db_regs_t *regs;
262 {
263 register db_watchpoint_t watch;
264 db_watchpoint_t found = 0;
265
266 for (watch = db_watchpoint_list;
267 watch != 0;
268 watch = watch->link)
269 if (db_map_equal(watch->map, map)) {
270 if ((watch->loaddr <= addr) &&
271 (addr < watch->hiaddr))
272 return (TRUE);
273 else if ((trunc_page(watch->loaddr) <= addr) &&
274 (addr < round_page(watch->hiaddr)))
275 found = watch;
276 }
277
278 /*
279 * We didn't hit exactly on a watchpoint, but we are
280 * in a protected region. We want to single-step
281 * and then re-protect.
282 */
283
284 if (found) {
285 db_watchpoints_inserted = FALSE;
286 db_single_step(regs);
287 }
288
289 return (FALSE);
290 }
291 #endif
292
293
294
295 /* Delete hardware watchpoint */
296 /*ARGSUSED*/
297 void
298 db_deletehwatch_cmd(addr, have_addr, count, modif)
299 db_expr_t addr;
300 boolean_t have_addr;
301 db_expr_t count;
302 char * modif;
303 {
304 int rc;
305
306 if (count < 0)
307 count = 4;
308
309 rc = db_md_clr_watchpoint(addr, count);
310 if (rc < 0)
311 db_printf("hardware watchpoint could not be deleted\n");
312 }
313
314 /* Set hardware watchpoint */
315 /*ARGSUSED*/
316 void
317 db_hwatchpoint_cmd(addr, have_addr, count, modif)
318 db_expr_t addr;
319 boolean_t have_addr;
320 db_expr_t count;
321 char * modif;
322 {
323 int rc;
324
325 if (count < 0)
326 count = 4;
327
328 rc = db_md_set_watchpoint(addr, count);
329 if (rc < 0)
330 db_printf("hardware watchpoint could not be set\n");
331 }
332
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