1 /*-
2 * SPDX-License-Identifier: MIT-CMU
3 *
4 * Mach Operating System
5 * Copyright (c) 1991,1990 Carnegie Mellon University
6 * All Rights Reserved.
7 *
8 * Permission to use, copy, modify and distribute this software and its
9 * documentation is hereby granted, provided that both the copyright
10 * notice and this permission notice appear in all copies of the
11 * software, derivative works or modified versions, and any portions
12 * thereof, and that both notices appear in supporting documentation.
13 *
14 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS
15 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
16 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
17 *
18 * Carnegie Mellon requests users of this software to return to
19 *
20 * Software Distribution Coordinator or [email protected]
21 * School of Computer Science
22 * Carnegie Mellon University
23 * Pittsburgh PA 15213-3890
24 *
25 * any improvements or extensions that they make and grant Carnegie the
26 * rights to redistribute these changes.
27 */
28 /*
29 * Author: Richard P. Draves, Carnegie Mellon University
30 * Date: 10/90
31 */
32
33 #include <sys/cdefs.h>
34 #include <sys/param.h>
35 #include <sys/kdb.h>
36 #include <sys/kernel.h>
37 #include <sys/lock.h>
38 #include <sys/proc.h>
39
40 #include <vm/vm.h>
41 #include <vm/pmap.h>
42 #include <vm/vm_map.h>
43
44 #include <machine/kdb.h>
45
46 #include <ddb/ddb.h>
47 #include <ddb/db_watch.h>
48
49 /*
50 * Watchpoints.
51 */
52
53 static bool 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(void);
62 static void db_watchpoint_free(db_watchpoint_t watch);
63 static void db_delete_watchpoint(vm_map_t map, db_addr_t addr);
64 #ifdef notused
65 static bool db_find_watchpoint(vm_map_t map, db_addr_t addr,
66 db_regs_t *regs);
67 #endif
68 static void db_list_watchpoints(void);
69 static void db_set_watchpoint(vm_map_t map, db_addr_t addr,
70 vm_size_t size);
71
72 static db_watchpoint_t
db_watchpoint_alloc(void)73 db_watchpoint_alloc(void)
74 {
75 db_watchpoint_t watch;
76
77 if ((watch = db_free_watchpoints) != 0) {
78 db_free_watchpoints = watch->link;
79 return (watch);
80 }
81 if (db_next_free_watchpoint == &db_watch_table[NWATCHPOINTS]) {
82 db_printf("All watchpoints used.\n");
83 return (0);
84 }
85 watch = db_next_free_watchpoint;
86 db_next_free_watchpoint++;
87
88 return (watch);
89 }
90
91 static void
db_watchpoint_free(db_watchpoint_t watch)92 db_watchpoint_free(db_watchpoint_t watch)
93 {
94 watch->link = db_free_watchpoints;
95 db_free_watchpoints = watch;
96 }
97
98 static void
db_set_watchpoint(vm_map_t map,db_addr_t addr,vm_size_t size)99 db_set_watchpoint(vm_map_t map, db_addr_t addr, vm_size_t size)
100 {
101 db_watchpoint_t watch;
102
103 if (map == NULL) {
104 db_printf("No map.\n");
105 return;
106 }
107
108 /*
109 * Should we do anything fancy with overlapping regions?
110 */
111
112 for (watch = db_watchpoint_list;
113 watch != 0;
114 watch = watch->link)
115 if (db_map_equal(watch->map, map) &&
116 (watch->loaddr == addr) &&
117 (watch->hiaddr == addr+size)) {
118 db_printf("Already set.\n");
119 return;
120 }
121
122 watch = db_watchpoint_alloc();
123 if (watch == 0) {
124 db_printf("Too many watchpoints.\n");
125 return;
126 }
127
128 watch->map = map;
129 watch->loaddr = addr;
130 watch->hiaddr = addr+size;
131
132 watch->link = db_watchpoint_list;
133 db_watchpoint_list = watch;
134
135 db_watchpoints_inserted = false;
136 }
137
138 static void
db_delete_watchpoint(vm_map_t map,db_addr_t addr)139 db_delete_watchpoint(vm_map_t map, db_addr_t addr)
140 {
141 db_watchpoint_t watch;
142 db_watchpoint_t *prev;
143
144 for (prev = &db_watchpoint_list;
145 (watch = *prev) != 0;
146 prev = &watch->link)
147 if (db_map_equal(watch->map, map) &&
148 (watch->loaddr <= addr) &&
149 (addr < watch->hiaddr)) {
150 *prev = watch->link;
151 db_watchpoint_free(watch);
152 return;
153 }
154
155 db_printf("Not set.\n");
156 }
157
158 static void
db_list_watchpoints(void)159 db_list_watchpoints(void)
160 {
161 db_watchpoint_t watch;
162
163 if (db_watchpoint_list == 0) {
164 db_printf("No watchpoints set\n");
165 return;
166 }
167
168 #ifdef __LP64__
169 db_printf(" Map Address Size\n");
170 #else
171 db_printf(" Map Address Size\n");
172 #endif
173 for (watch = db_watchpoint_list;
174 watch != 0;
175 watch = watch->link)
176 #ifdef __LP64__
177 db_printf("%s%16p %16lx %lx\n",
178 #else
179 db_printf("%s%8p %8lx %lx\n",
180 #endif
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
db_deletewatch_cmd(db_expr_t addr,bool have_addr,db_expr_t count,char * modif)189 db_deletewatch_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
190 char *modif)
191 {
192 db_delete_watchpoint(db_map_addr(addr), addr);
193 }
194
195 /* Set watchpoint */
196 /*ARGSUSED*/
197 void
db_watchpoint_cmd(db_expr_t addr,bool have_addr,db_expr_t count,char * modif)198 db_watchpoint_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
199 char *modif)
200 {
201 vm_size_t size;
202 db_expr_t value;
203
204 if (db_expression(&value))
205 size = (vm_size_t) value;
206 else
207 size = 4;
208 db_skip_to_eol();
209
210 db_set_watchpoint(db_map_addr(addr), addr, size);
211 }
212
213 /*
214 * At least one non-optional show-command must be implemented using
215 * DB_SHOW_COMMAND() so that db_show_cmd_set gets created. Here is one.
216 */
DB_SHOW_COMMAND_FLAGS(watches,db_listwatch_cmd,DB_CMD_MEMSAFE)217 DB_SHOW_COMMAND_FLAGS(watches, db_listwatch_cmd, DB_CMD_MEMSAFE)
218 {
219 db_list_watchpoints();
220 db_md_list_watchpoints();
221 }
222
223 void
db_set_watchpoints(void)224 db_set_watchpoints(void)
225 {
226 db_watchpoint_t watch;
227
228 if (!db_watchpoints_inserted) {
229 for (watch = db_watchpoint_list;
230 watch != 0;
231 watch = watch->link)
232 pmap_protect(watch->map->pmap,
233 trunc_page(watch->loaddr),
234 round_page(watch->hiaddr),
235 VM_PROT_READ);
236
237 db_watchpoints_inserted = true;
238 }
239 }
240
241 void
db_clear_watchpoints(void)242 db_clear_watchpoints(void)
243 {
244 db_watchpoints_inserted = false;
245 }
246
247 #ifdef notused
248 static bool
db_find_watchpoint(vm_map_t map,db_addr_t addr,db_regs_t regs)249 db_find_watchpoint(vm_map_t map, db_addr_t addr, db_regs_t regs)
250 {
251 db_watchpoint_t watch;
252 db_watchpoint_t found = 0;
253
254 for (watch = db_watchpoint_list;
255 watch != 0;
256 watch = watch->link)
257 if (db_map_equal(watch->map, map)) {
258 if ((watch->loaddr <= addr) &&
259 (addr < watch->hiaddr))
260 return (true);
261 else if ((trunc_page(watch->loaddr) <= addr) &&
262 (addr < round_page(watch->hiaddr)))
263 found = watch;
264 }
265
266 /*
267 * We didn't hit exactly on a watchpoint, but we are
268 * in a protected region. We want to single-step
269 * and then re-protect.
270 */
271
272 if (found) {
273 db_watchpoints_inserted = false;
274 db_single_step(regs);
275 }
276
277 return (false);
278 }
279 #endif
280
281 /* Delete hardware watchpoint */
282 void
db_deletehwatch_cmd(db_expr_t addr,bool have_addr,db_expr_t size,char * modif)283 db_deletehwatch_cmd(db_expr_t addr, bool have_addr, db_expr_t size,
284 char *modif)
285 {
286 int rc;
287
288 if (size < 0)
289 size = 4;
290
291 rc = kdb_cpu_clr_watchpoint((vm_offset_t)addr, (vm_size_t)size);
292 switch (rc) {
293 case ENXIO:
294 /* Not supported, ignored. */
295 break;
296 case EINVAL:
297 db_printf("Invalid watchpoint address or size.\n");
298 break;
299 default:
300 if (rc != 0)
301 db_printf("Hardware watchpoint could not be deleted, "
302 "status=%d\n", rc);
303 break;
304 }
305 }
306
307 /* Set hardware watchpoint */
308 void
db_hwatchpoint_cmd(db_expr_t addr,bool have_addr,db_expr_t size,char * modif)309 db_hwatchpoint_cmd(db_expr_t addr, bool have_addr, db_expr_t size,
310 char *modif)
311 {
312 int rc;
313
314 if (size < 0)
315 size = 4;
316
317 rc = kdb_cpu_set_watchpoint((vm_offset_t)addr, (vm_size_t)size,
318 KDB_DBG_ACCESS_W);
319
320 switch (rc) {
321 case EINVAL:
322 db_printf("Invalid watchpoint size or address.\n");
323 break;
324 case EBUSY:
325 db_printf("No hardware watchpoints available.\n");
326 break;
327 case ENXIO:
328 db_printf("Hardware watchpoints are not supported on this platform.\n");
329 break;
330 default:
331 if (rc != 0)
332 db_printf("Could not set hardware watchpoint, "
333 "status=%d\n", rc);
334 }
335 }
336