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 1.20.2.1 2001/07/25 01:00:08 bsd 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/kernel.h>
36
37 #include <vm/vm.h>
38 #include <sys/lock.h>
39 #include <vm/pmap.h>
40 #include <vm/vm_map.h>
41
42 #include <ddb/ddb.h>
43 #include <ddb/db_watch.h>
44
45 /*
46 * Watchpoints.
47 */
48
49 static boolean_t db_watchpoints_inserted = TRUE;
50
51 #define NWATCHPOINTS 100
52 static struct db_watchpoint db_watch_table[NWATCHPOINTS];
53 static db_watchpoint_t db_next_free_watchpoint = &db_watch_table[0];
54 static db_watchpoint_t db_free_watchpoints = 0;
55 static db_watchpoint_t db_watchpoint_list = 0;
56
57 static db_watchpoint_t db_watchpoint_alloc (void);
58 static void db_watchpoint_free (db_watchpoint_t watch);
59 static void db_delete_watchpoint (vm_map_t map,
60 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
db_watchpoint_alloc(void)75 db_watchpoint_alloc(void)
76 {
77 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
db_watchpoint_free(db_watchpoint_t watch)94 db_watchpoint_free(db_watchpoint_t watch)
95 {
96 watch->link = db_free_watchpoints;
97 db_free_watchpoints = watch;
98 }
99
100 static void
db_set_watchpoint(vm_map_t map,db_addr_t addr,vm_size_t size)101 db_set_watchpoint(vm_map_t map, db_addr_t addr, vm_size_t size)
102 {
103 db_watchpoint_t watch;
104
105 if (map == NULL) {
106 db_printf("No map.\n");
107 return;
108 }
109
110 /*
111 * Should we do anything fancy with overlapping regions?
112 */
113
114 for (watch = db_watchpoint_list;
115 watch != 0;
116 watch = watch->link)
117 if (db_map_equal(watch->map, map) &&
118 (watch->loaddr == addr) &&
119 (watch->hiaddr == addr+size)) {
120 db_printf("Already set.\n");
121 return;
122 }
123
124 watch = db_watchpoint_alloc();
125 if (watch == 0) {
126 db_printf("Too many watchpoints.\n");
127 return;
128 }
129
130 watch->map = map;
131 watch->loaddr = addr;
132 watch->hiaddr = addr+size;
133
134 watch->link = db_watchpoint_list;
135 db_watchpoint_list = watch;
136
137 db_watchpoints_inserted = FALSE;
138 }
139
140 static void
db_delete_watchpoint(vm_map_t map,db_addr_t addr)141 db_delete_watchpoint(vm_map_t map, db_addr_t addr)
142 {
143 db_watchpoint_t watch;
144 db_watchpoint_t *prev;
145
146 for (prev = &db_watchpoint_list;
147 (watch = *prev) != 0;
148 prev = &watch->link)
149 if (db_map_equal(watch->map, map) &&
150 (watch->loaddr <= addr) &&
151 (addr < watch->hiaddr)) {
152 *prev = watch->link;
153 db_watchpoint_free(watch);
154 return;
155 }
156
157 db_printf("Not set.\n");
158 }
159
160 static void
db_list_watchpoints(void)161 db_list_watchpoints(void)
162 {
163 db_watchpoint_t watch;
164
165 if (db_watchpoint_list == 0) {
166 db_printf("No watchpoints set\n");
167 return;
168 }
169
170 db_printf(" Map Address Size\n");
171 for (watch = db_watchpoint_list;
172 watch != 0;
173 watch = watch->link)
174 db_printf("%s%8p %8lx %lx\n",
175 db_map_current(watch->map) ? "*" : " ",
176 (void *)watch->map, (long)watch->loaddr,
177 (long)watch->hiaddr - (long)watch->loaddr);
178 }
179
180 /* Delete watchpoint */
181 /*ARGSUSED*/
182 void
db_deletewatch_cmd(db_expr_t addr,boolean_t have_addr,db_expr_t count,char * modif)183 db_deletewatch_cmd(db_expr_t addr, boolean_t have_addr, db_expr_t count,
184 char *modif)
185 {
186 db_delete_watchpoint(db_map_addr(addr), addr);
187 }
188
189 /* Set watchpoint */
190 /*ARGSUSED*/
191 void
db_watchpoint_cmd(db_expr_t addr,boolean_t have_addr,db_expr_t count,char * modif)192 db_watchpoint_cmd(db_expr_t addr, boolean_t have_addr, db_expr_t count,
193 char *modif)
194 {
195 vm_size_t size;
196 db_expr_t value;
197
198 if (db_expression(&value))
199 size = (vm_size_t) value;
200 else
201 size = 4;
202 db_skip_to_eol();
203
204 db_set_watchpoint(db_map_addr(addr), addr, size);
205 }
206
207 /*
208 * At least one non-optional show-command must be implemented using
209 * DB_SHOW_COMMAND() so that db_show_cmd_set gets created. Here is one.
210 */
DB_SHOW_COMMAND(watches,db_listwatch_cmd)211 DB_SHOW_COMMAND(watches, db_listwatch_cmd)
212 {
213 db_list_watchpoints();
214 db_md_list_watchpoints();
215 }
216
217 void
db_set_watchpoints(void)218 db_set_watchpoints(void)
219 {
220 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
231 db_watchpoints_inserted = TRUE;
232 }
233 }
234
235 void
db_clear_watchpoints(void)236 db_clear_watchpoints(void)
237 {
238 db_watchpoints_inserted = FALSE;
239 }
240
241 #ifdef notused
242 static boolean_t
db_find_watchpoint(vm_map_t map,db_addr_t addr,db_regs_t * regs)243 db_find_watchpoint(vm_map_t map, db_addr_t addr, db_regs_t *regs)
244 {
245 db_watchpoint_t watch;
246 db_watchpoint_t found = 0;
247
248 for (watch = db_watchpoint_list;
249 watch != 0;
250 watch = watch->link)
251 if (db_map_equal(watch->map, map)) {
252 if ((watch->loaddr <= addr) &&
253 (addr < watch->hiaddr))
254 return (TRUE);
255 else if ((trunc_page(watch->loaddr) <= addr) &&
256 (addr < round_page(watch->hiaddr)))
257 found = watch;
258 }
259
260 /*
261 * We didn't hit exactly on a watchpoint, but we are
262 * in a protected region. We want to single-step
263 * and then re-protect.
264 */
265
266 if (found) {
267 db_watchpoints_inserted = FALSE;
268 db_single_step(regs);
269 }
270
271 return (FALSE);
272 }
273 #endif
274
275
276
277 /* Delete hardware watchpoint */
278 /*ARGSUSED*/
279 void
db_deletehwatch_cmd(db_expr_t addr,boolean_t have_addr,db_expr_t count,char * modif)280 db_deletehwatch_cmd(db_expr_t addr, boolean_t have_addr, db_expr_t count,
281 char *modif)
282 {
283 int rc;
284
285 if (count < 0)
286 count = 4;
287
288 rc = db_md_clr_watchpoint(addr, count);
289 if (rc < 0)
290 db_printf("hardware watchpoint could not be deleted\n");
291 }
292
293 /* Set hardware watchpoint */
294 /*ARGSUSED*/
295 void
db_hwatchpoint_cmd(db_expr_t addr,boolean_t have_addr,db_expr_t count,char * modif)296 db_hwatchpoint_cmd(db_expr_t addr, boolean_t have_addr, db_expr_t count,
297 char *modif)
298 {
299 int rc;
300
301 if (count < 0)
302 count = 4;
303
304 rc = db_md_set_watchpoint(addr, count);
305 if (rc < 0)
306 db_printf("hardware watchpoint could not be set\n");
307 }
308
309 void
db_invltlb_cmd(db_expr_t addr,boolean_t have_addr,db_expr_t count,char * modif)310 db_invltlb_cmd(db_expr_t addr, boolean_t have_addr, db_expr_t count,
311 char *modif)
312 {
313 cpu_invltlb();
314 }
315