FreeBSD/Linux Kernel Cross Reference
sys/ddb/db_break.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 /*
28 * Author: David B. Golub, Carnegie Mellon University
29 * Date: 7/90
30 */
31 /*
32 * Breakpoints.
33 */
34
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD: src/sys/ddb/db_break.c,v 1.25 2005/01/06 01:34:41 imp Exp $");
37
38 #include "opt_comconsole.h"
39
40 #include <sys/param.h>
41
42 #include <vm/vm.h>
43 #include <vm/vm_kern.h>
44
45 #include <ddb/ddb.h>
46 #include <ddb/db_break.h>
47 #include <ddb/db_access.h>
48 #include <ddb/db_sym.h>
49
50 #define NBREAKPOINTS 100
51 static struct db_breakpoint db_break_table[NBREAKPOINTS];
52 static db_breakpoint_t db_next_free_breakpoint = &db_break_table[0];
53 static db_breakpoint_t db_free_breakpoints = 0;
54 static db_breakpoint_t db_breakpoint_list = 0;
55
56 static db_breakpoint_t db_breakpoint_alloc(void);
57 static void db_breakpoint_free(db_breakpoint_t bkpt);
58 static void db_delete_breakpoint(vm_map_t map, db_addr_t addr);
59 static db_breakpoint_t db_find_breakpoint(vm_map_t map, db_addr_t addr);
60 static void db_list_breakpoints(void);
61 static void db_set_breakpoint(vm_map_t map, db_addr_t addr, int count);
62
63 static db_breakpoint_t
64 db_breakpoint_alloc()
65 {
66 register db_breakpoint_t bkpt;
67
68 if ((bkpt = db_free_breakpoints) != 0) {
69 db_free_breakpoints = bkpt->link;
70 return (bkpt);
71 }
72 if (db_next_free_breakpoint == &db_break_table[NBREAKPOINTS]) {
73 db_printf("All breakpoints used.\n");
74 return (0);
75 }
76 bkpt = db_next_free_breakpoint;
77 db_next_free_breakpoint++;
78
79 return (bkpt);
80 }
81
82 static void
83 db_breakpoint_free(bkpt)
84 register db_breakpoint_t bkpt;
85 {
86 bkpt->link = db_free_breakpoints;
87 db_free_breakpoints = bkpt;
88 }
89
90 static void
91 db_set_breakpoint(map, addr, count)
92 vm_map_t map;
93 db_addr_t addr;
94 int count;
95 {
96 register db_breakpoint_t bkpt;
97
98 if (db_find_breakpoint(map, addr)) {
99 db_printf("Already set.\n");
100 return;
101 }
102
103 bkpt = db_breakpoint_alloc();
104 if (bkpt == 0) {
105 db_printf("Too many breakpoints.\n");
106 return;
107 }
108
109 bkpt->map = map;
110 bkpt->address = addr;
111 bkpt->flags = 0;
112 bkpt->init_count = count;
113 bkpt->count = count;
114
115 bkpt->link = db_breakpoint_list;
116 db_breakpoint_list = bkpt;
117 }
118
119 static void
120 db_delete_breakpoint(map, addr)
121 vm_map_t map;
122 db_addr_t addr;
123 {
124 register db_breakpoint_t bkpt;
125 register db_breakpoint_t *prev;
126
127 for (prev = &db_breakpoint_list;
128 (bkpt = *prev) != 0;
129 prev = &bkpt->link) {
130 if (db_map_equal(bkpt->map, map) &&
131 (bkpt->address == addr)) {
132 *prev = bkpt->link;
133 break;
134 }
135 }
136 if (bkpt == 0) {
137 db_printf("Not set.\n");
138 return;
139 }
140
141 db_breakpoint_free(bkpt);
142 }
143
144 static db_breakpoint_t
145 db_find_breakpoint(map, addr)
146 vm_map_t map;
147 db_addr_t addr;
148 {
149 register db_breakpoint_t bkpt;
150
151 for (bkpt = db_breakpoint_list;
152 bkpt != 0;
153 bkpt = bkpt->link)
154 {
155 if (db_map_equal(bkpt->map, map) &&
156 (bkpt->address == addr))
157 return (bkpt);
158 }
159 return (0);
160 }
161
162 db_breakpoint_t
163 db_find_breakpoint_here(addr)
164 db_addr_t addr;
165 {
166 return db_find_breakpoint(db_map_addr(addr), addr);
167 }
168
169 static boolean_t db_breakpoints_inserted = TRUE;
170
171 #ifndef BKPT_WRITE
172 #define BKPT_WRITE(addr, storage) \
173 do { \
174 *storage = db_get_value(addr, BKPT_SIZE, FALSE); \
175 db_put_value(addr, BKPT_SIZE, BKPT_SET(*storage)); \
176 } while (0)
177 #endif
178
179 #ifndef BKPT_CLEAR
180 #define BKPT_CLEAR(addr, storage) \
181 db_put_value(addr, BKPT_SIZE, *storage)
182 #endif
183
184 void
185 db_set_breakpoints()
186 {
187 register db_breakpoint_t bkpt;
188
189 if (!db_breakpoints_inserted) {
190
191 for (bkpt = db_breakpoint_list;
192 bkpt != 0;
193 bkpt = bkpt->link)
194 if (db_map_current(bkpt->map)) {
195 BKPT_WRITE(bkpt->address, &bkpt->bkpt_inst);
196 }
197 db_breakpoints_inserted = TRUE;
198 }
199 }
200
201 void
202 db_clear_breakpoints()
203 {
204 register db_breakpoint_t bkpt;
205
206 if (db_breakpoints_inserted) {
207
208 for (bkpt = db_breakpoint_list;
209 bkpt != 0;
210 bkpt = bkpt->link)
211 if (db_map_current(bkpt->map)) {
212 BKPT_CLEAR(bkpt->address, &bkpt->bkpt_inst);
213 }
214 db_breakpoints_inserted = FALSE;
215 }
216 }
217
218 #ifdef SOFTWARE_SSTEP
219 /*
220 * Set a temporary breakpoint.
221 * The instruction is changed immediately,
222 * so the breakpoint does not have to be on the breakpoint list.
223 */
224 db_breakpoint_t
225 db_set_temp_breakpoint(addr)
226 db_addr_t addr;
227 {
228 register db_breakpoint_t bkpt;
229
230 bkpt = db_breakpoint_alloc();
231 if (bkpt == 0) {
232 db_printf("Too many breakpoints.\n");
233 return 0;
234 }
235
236 bkpt->map = NULL;
237 bkpt->address = addr;
238 bkpt->flags = BKPT_TEMP;
239 bkpt->init_count = 1;
240 bkpt->count = 1;
241
242 BKPT_WRITE(bkpt->address, &bkpt->bkpt_inst);
243 return bkpt;
244 }
245
246 void
247 db_delete_temp_breakpoint(bkpt)
248 db_breakpoint_t bkpt;
249 {
250 BKPT_CLEAR(bkpt->address, &bkpt->bkpt_inst);
251 db_breakpoint_free(bkpt);
252 }
253 #endif /* SOFTWARE_SSTEP */
254
255 /*
256 * List breakpoints.
257 */
258 static void
259 db_list_breakpoints()
260 {
261 register db_breakpoint_t bkpt;
262
263 if (db_breakpoint_list == 0) {
264 db_printf("No breakpoints set\n");
265 return;
266 }
267
268 db_printf(" Map Count Address\n");
269 for (bkpt = db_breakpoint_list;
270 bkpt != 0;
271 bkpt = bkpt->link) {
272 db_printf("%s%8p %5d ",
273 db_map_current(bkpt->map) ? "*" : " ",
274 (void *)bkpt->map, bkpt->init_count);
275 db_printsym(bkpt->address, DB_STGY_PROC);
276 db_printf("\n");
277 }
278 }
279
280 /* Delete breakpoint */
281 /*ARGSUSED*/
282 void
283 db_delete_cmd(addr, have_addr, count, modif)
284 db_expr_t addr;
285 boolean_t have_addr;
286 db_expr_t count;
287 char * modif;
288 {
289 db_delete_breakpoint(db_map_addr(addr), (db_addr_t)addr);
290 }
291
292 /* Set breakpoint with skip count */
293 /*ARGSUSED*/
294 void
295 db_breakpoint_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 if (count == -1)
302 count = 1;
303
304 db_set_breakpoint(db_map_addr(addr), (db_addr_t)addr, count);
305 }
306
307 /* list breakpoints */
308 void
309 db_listbreak_cmd(dummy1, dummy2, dummy3, dummy4)
310 db_expr_t dummy1;
311 boolean_t dummy2;
312 db_expr_t dummy3;
313 char * dummy4;
314 {
315 db_list_breakpoints();
316 }
317
318 /*
319 * We want ddb to be usable before most of the kernel has been
320 * initialized. In particular, current_thread() or kernel_map
321 * (or both) may be null.
322 */
323
324 boolean_t
325 db_map_equal(map1, map2)
326 vm_map_t map1, map2;
327 {
328 return ((map1 == map2) ||
329 ((map1 == NULL) && (map2 == kernel_map)) ||
330 ((map1 == kernel_map) && (map2 == NULL)));
331 }
332
333 boolean_t
334 db_map_current(map)
335 vm_map_t map;
336 {
337 #if 0
338 thread_t thread;
339
340 return ((map == NULL) ||
341 (map == kernel_map) ||
342 (((thread = current_thread()) != NULL) &&
343 (map == thread->task->map)));
344 #else
345 return (1);
346 #endif
347 }
348
349 vm_map_t
350 db_map_addr(addr)
351 vm_offset_t addr;
352 {
353 #if 0
354 thread_t thread;
355
356 /*
357 * We want to return kernel_map for all
358 * non-user addresses, even when debugging
359 * kernel tasks with their own maps.
360 */
361
362 if ((VM_MIN_ADDRESS <= addr) &&
363 (addr < VM_MAX_ADDRESS) &&
364 ((thread = current_thread()) != NULL))
365 return thread->task->map;
366 else
367 #endif
368 return kernel_map;
369 }
370
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