da7681a288e8340b7182bea616341a1e8b59a710
[dragonfly.git] / 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 1.20.2.1 2001/07/25 01:00:08 bsd Exp $
27  * $DragonFly: src/sys/ddb/db_watch.c,v 1.2 2003/06/17 04:28:20 dillon Exp $
28  */
29
30 /*
31  *      Author: Richard P. Draves, Carnegie Mellon University
32  *      Date:   10/90
33  */
34
35 #include <sys/param.h>
36 #include <sys/kernel.h>
37
38 #include <vm/vm.h>
39 #include <sys/lock.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 __P((void));
59 static void             db_watchpoint_free __P((db_watchpoint_t watch));
60 static void             db_delete_watchpoint __P((vm_map_t map,
61                                         db_addr_t addr));
62 #ifdef notused
63 static boolean_t        db_find_watchpoint __P((vm_map_t map, db_addr_t addr,
64                                         db_regs_t *regs));
65 #endif
66 static void             db_list_watchpoints __P((void));
67 static void             db_set_watchpoint __P((vm_map_t map, db_addr_t addr,
68                                        vm_size_t size));
69
70 int  db_md_set_watchpoint   __P((db_expr_t addr, db_expr_t size));
71 int  db_md_clr_watchpoint   __P((db_expr_t addr, db_expr_t size));
72 void db_md_list_watchpoints __P((void));
73
74
75 db_watchpoint_t
76 db_watchpoint_alloc()
77 {
78         register db_watchpoint_t        watch;
79
80         if ((watch = db_free_watchpoints) != 0) {
81             db_free_watchpoints = watch->link;
82             return (watch);
83         }
84         if (db_next_free_watchpoint == &db_watch_table[NWATCHPOINTS]) {
85             db_printf("All watchpoints used.\n");
86             return (0);
87         }
88         watch = db_next_free_watchpoint;
89         db_next_free_watchpoint++;
90
91         return (watch);
92 }
93
94 void
95 db_watchpoint_free(watch)
96         register db_watchpoint_t        watch;
97 {
98         watch->link = db_free_watchpoints;
99         db_free_watchpoints = watch;
100 }
101
102 static void
103 db_set_watchpoint(map, addr, size)
104         vm_map_t        map;
105         db_addr_t       addr;
106         vm_size_t       size;
107 {
108         register db_watchpoint_t        watch;
109
110         if (map == NULL) {
111             db_printf("No map.\n");
112             return;
113         }
114
115         /*
116          *      Should we do anything fancy with overlapping regions?
117          */
118
119         for (watch = db_watchpoint_list;
120              watch != 0;
121              watch = watch->link)
122             if (db_map_equal(watch->map, map) &&
123                 (watch->loaddr == addr) &&
124                 (watch->hiaddr == addr+size)) {
125                 db_printf("Already set.\n");
126                 return;
127             }
128
129         watch = db_watchpoint_alloc();
130         if (watch == 0) {
131             db_printf("Too many watchpoints.\n");
132             return;
133         }
134
135         watch->map = map;
136         watch->loaddr = addr;
137         watch->hiaddr = addr+size;
138
139         watch->link = db_watchpoint_list;
140         db_watchpoint_list = watch;
141
142         db_watchpoints_inserted = FALSE;
143 }
144
145 static void
146 db_delete_watchpoint(map, addr)
147         vm_map_t        map;
148         db_addr_t       addr;
149 {
150         register db_watchpoint_t        watch;
151         register db_watchpoint_t        *prev;
152
153         for (prev = &db_watchpoint_list;
154              (watch = *prev) != 0;
155              prev = &watch->link)
156             if (db_map_equal(watch->map, map) &&
157                 (watch->loaddr <= addr) &&
158                 (addr < watch->hiaddr)) {
159                 *prev = watch->link;
160                 db_watchpoint_free(watch);
161                 return;
162             }
163
164         db_printf("Not set.\n");
165 }
166
167 static void
168 db_list_watchpoints()
169 {
170         register db_watchpoint_t        watch;
171
172         if (db_watchpoint_list == 0) {
173             db_printf("No watchpoints set\n");
174             return;
175         }
176
177         db_printf(" Map        Address  Size\n");
178         for (watch = db_watchpoint_list;
179              watch != 0;
180              watch = watch->link)
181             db_printf("%s%8p  %8lx  %lx\n",
182                       db_map_current(watch->map) ? "*" : " ",
183                       (void *)watch->map, (long)watch->loaddr,
184                       (long)watch->hiaddr - (long)watch->loaddr);
185 }
186
187 /* Delete watchpoint */
188 /*ARGSUSED*/
189 void
190 db_deletewatch_cmd(addr, have_addr, count, modif)
191         db_expr_t       addr;
192         boolean_t       have_addr;
193         db_expr_t       count;
194         char *          modif;
195 {
196         db_delete_watchpoint(db_map_addr(addr), addr);
197 }
198
199 /* Set watchpoint */
200 /*ARGSUSED*/
201 void
202 db_watchpoint_cmd(addr, have_addr, count, modif)
203         db_expr_t       addr;
204         boolean_t       have_addr;
205         db_expr_t       count;
206         char *          modif;
207 {
208         vm_size_t       size;
209         db_expr_t       value;
210
211         if (db_expression(&value))
212             size = (vm_size_t) value;
213         else
214             size = 4;
215         db_skip_to_eol();
216
217         db_set_watchpoint(db_map_addr(addr), addr, size);
218 }
219
220 /*
221  * At least one non-optional show-command must be implemented using
222  * DB_SHOW_COMMAND() so that db_show_cmd_set gets created.  Here is one.
223  */
224 DB_SHOW_COMMAND(watches, db_listwatch_cmd)
225 {
226         db_list_watchpoints();
227         db_md_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
290
291
292
293 /* Delete hardware watchpoint */
294 /*ARGSUSED*/
295 void
296 db_deletehwatch_cmd(addr, have_addr, count, modif)
297         db_expr_t       addr;
298         boolean_t       have_addr;
299         db_expr_t       count;
300         char *          modif;
301 {
302         int rc;
303
304         if (count < 0)
305                 count = 4;
306
307         rc = db_md_clr_watchpoint(addr, count);
308         if (rc < 0)
309                 db_printf("hardware watchpoint could not be deleted\n");
310 }
311
312 /* Set hardware watchpoint */
313 /*ARGSUSED*/
314 void
315 db_hwatchpoint_cmd(addr, have_addr, count, modif)
316         db_expr_t       addr;
317         boolean_t       have_addr;
318         db_expr_t       count;
319         char *          modif;
320 {
321         int rc;
322
323         if (count < 0)
324                 count = 4;
325
326         rc = db_md_set_watchpoint(addr, count);
327         if (rc < 0)
328                 db_printf("hardware watchpoint could not be set\n");
329 }