xref: /freebsd/sys/ddb/db_break.c (revision e627b39baccd1ec9129690167cf5e6d860509655)
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  *	$Id: db_break.c,v 1.10 1995/12/10 13:32:33 phk Exp $
27  */
28 
29 /*
30  *	Author: David B. Golub, Carnegie Mellon University
31  *	Date:	7/90
32  */
33 /*
34  * Breakpoints.
35  */
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 
39 #include <vm/vm.h>
40 #include <vm/vm_kern.h>
41 
42 #include <ddb/ddb.h>
43 #include <ddb/db_lex.h>
44 #include <ddb/db_break.h>
45 #include <ddb/db_access.h>
46 #include <ddb/db_sym.h>
47 
48 #define	NBREAKPOINTS	100
49 static struct db_breakpoint	db_break_table[NBREAKPOINTS];
50 static db_breakpoint_t		db_next_free_breakpoint = &db_break_table[0];
51 static db_breakpoint_t		db_free_breakpoints = 0;
52 static db_breakpoint_t		db_breakpoint_list = 0;
53 
54 static db_breakpoint_t	db_breakpoint_alloc __P((void));
55 static void	db_breakpoint_free __P((db_breakpoint_t bkpt));
56 static void	db_delete_breakpoint __P((vm_map_t map, db_addr_t addr));
57 static db_breakpoint_t	db_find_breakpoint __P((vm_map_t map, db_addr_t addr));
58 static void	db_list_breakpoints __P((void));
59 static void	db_set_breakpoint __P((vm_map_t map, db_addr_t addr,
60 				       int count));
61 #ifdef notused
62 static db_breakpoint_t	db_set_temp_breakpoint __P((db_addr_t addr));
63 static void	db_delete_temp_breakpoint __P((db_breakpoint_t bkpt));
64 #endif
65 
66 static db_breakpoint_t
67 db_breakpoint_alloc()
68 {
69 	register db_breakpoint_t	bkpt;
70 
71 	if ((bkpt = db_free_breakpoints) != 0) {
72 	    db_free_breakpoints = bkpt->link;
73 	    return (bkpt);
74 	}
75 	if (db_next_free_breakpoint == &db_break_table[NBREAKPOINTS]) {
76 	    db_printf("All breakpoints used.\n");
77 	    return (0);
78 	}
79 	bkpt = db_next_free_breakpoint;
80 	db_next_free_breakpoint++;
81 
82 	return (bkpt);
83 }
84 
85 static void
86 db_breakpoint_free(bkpt)
87 	register db_breakpoint_t	bkpt;
88 {
89 	bkpt->link = db_free_breakpoints;
90 	db_free_breakpoints = bkpt;
91 }
92 
93 static void
94 db_set_breakpoint(map, addr, count)
95 	vm_map_t	map;
96 	db_addr_t	addr;
97 	int		count;
98 {
99 	register db_breakpoint_t	bkpt;
100 
101 	if (db_find_breakpoint(map, addr)) {
102 	    db_printf("Already set.\n");
103 	    return;
104 	}
105 
106 	bkpt = db_breakpoint_alloc();
107 	if (bkpt == 0) {
108 	    db_printf("Too many breakpoints.\n");
109 	    return;
110 	}
111 
112 	bkpt->map = map;
113 	bkpt->address = addr;
114 	bkpt->flags = 0;
115 	bkpt->init_count = count;
116 	bkpt->count = count;
117 
118 	bkpt->link = db_breakpoint_list;
119 	db_breakpoint_list = bkpt;
120 }
121 
122 static void
123 db_delete_breakpoint(map, addr)
124 	vm_map_t	map;
125 	db_addr_t	addr;
126 {
127 	register db_breakpoint_t	bkpt;
128 	register db_breakpoint_t	*prev;
129 
130 	for (prev = &db_breakpoint_list;
131 	     (bkpt = *prev) != 0;
132 	     prev = &bkpt->link) {
133 	    if (db_map_equal(bkpt->map, map) &&
134 		(bkpt->address == addr)) {
135 		*prev = bkpt->link;
136 		break;
137 	    }
138 	}
139 	if (bkpt == 0) {
140 	    db_printf("Not set.\n");
141 	    return;
142 	}
143 
144 	db_breakpoint_free(bkpt);
145 }
146 
147 static db_breakpoint_t
148 db_find_breakpoint(map, addr)
149 	vm_map_t	map;
150 	db_addr_t	addr;
151 {
152 	register db_breakpoint_t	bkpt;
153 
154 	for (bkpt = db_breakpoint_list;
155 	     bkpt != 0;
156 	     bkpt = bkpt->link)
157 	{
158 	    if (db_map_equal(bkpt->map, map) &&
159 		(bkpt->address == addr))
160 		return (bkpt);
161 	}
162 	return (0);
163 }
164 
165 db_breakpoint_t
166 db_find_breakpoint_here(addr)
167 	db_addr_t	addr;
168 {
169     return db_find_breakpoint(db_map_addr(addr), addr);
170 }
171 
172 static boolean_t	db_breakpoints_inserted = TRUE;
173 
174 void
175 db_set_breakpoints()
176 {
177 	register db_breakpoint_t	bkpt;
178 
179 	if (!db_breakpoints_inserted) {
180 
181 	    for (bkpt = db_breakpoint_list;
182 	         bkpt != 0;
183 	         bkpt = bkpt->link)
184 		if (db_map_current(bkpt->map)) {
185 		    bkpt->bkpt_inst = db_get_value(bkpt->address,
186 						   BKPT_SIZE,
187 						   FALSE);
188 		    db_put_value(bkpt->address,
189 				 BKPT_SIZE,
190 				 BKPT_SET(bkpt->bkpt_inst));
191 		}
192 	    db_breakpoints_inserted = TRUE;
193 	}
194 }
195 
196 void
197 db_clear_breakpoints()
198 {
199 	register db_breakpoint_t	bkpt;
200 
201 	if (db_breakpoints_inserted) {
202 
203 	    for (bkpt = db_breakpoint_list;
204 	         bkpt != 0;
205 		 bkpt = bkpt->link)
206 		if (db_map_current(bkpt->map)) {
207 		    db_put_value(bkpt->address, BKPT_SIZE, bkpt->bkpt_inst);
208 		}
209 	    db_breakpoints_inserted = FALSE;
210 	}
211 }
212 
213 #ifdef notused
214 /*
215  * Set a temporary breakpoint.
216  * The instruction is changed immediately,
217  * so the breakpoint does not have to be on the breakpoint list.
218  */
219 static db_breakpoint_t
220 db_set_temp_breakpoint(addr)
221 	db_addr_t	addr;
222 {
223 	register db_breakpoint_t	bkpt;
224 
225 	bkpt = db_breakpoint_alloc();
226 	if (bkpt == 0) {
227 	    db_printf("Too many breakpoints.\n");
228 	    return 0;
229 	}
230 
231 	bkpt->map = NULL;
232 	bkpt->address = addr;
233 	bkpt->flags = BKPT_TEMP;
234 	bkpt->init_count = 1;
235 	bkpt->count = 1;
236 
237 	bkpt->bkpt_inst = db_get_value(bkpt->address, BKPT_SIZE, FALSE);
238 	db_put_value(bkpt->address, BKPT_SIZE, BKPT_SET(bkpt->bkpt_inst));
239 	return bkpt;
240 }
241 
242 static void
243 db_delete_temp_breakpoint(bkpt)
244 	db_breakpoint_t	bkpt;
245 {
246 	db_put_value(bkpt->address, BKPT_SIZE, bkpt->bkpt_inst);
247 	db_breakpoint_free(bkpt);
248 }
249 #endif
250 
251 /*
252  * List breakpoints.
253  */
254 static void
255 db_list_breakpoints()
256 {
257 	register db_breakpoint_t	bkpt;
258 
259 	if (db_breakpoint_list == 0) {
260 	    db_printf("No breakpoints set\n");
261 	    return;
262 	}
263 
264 	db_printf(" Map      Count    Address\n");
265 	for (bkpt = db_breakpoint_list;
266 	     bkpt != 0;
267 	     bkpt = bkpt->link)
268 	{
269 	    db_printf("%s%8x %5d    ",
270 		      db_map_current(bkpt->map) ? "*" : " ",
271 		      bkpt->map, bkpt->init_count);
272 	    db_printsym(bkpt->address, DB_STGY_PROC);
273 	    db_printf("\n");
274 	}
275 }
276 
277 /* Delete breakpoint */
278 /*ARGSUSED*/
279 void
280 db_delete_cmd(addr, have_addr, count, modif)
281 	db_expr_t	addr;
282 	boolean_t	have_addr;
283 	db_expr_t	count;
284 	char *		modif;
285 {
286 	db_delete_breakpoint(db_map_addr(addr), (db_addr_t)addr);
287 }
288 
289 /* Set breakpoint with skip count */
290 /*ARGSUSED*/
291 void
292 db_breakpoint_cmd(addr, have_addr, count, modif)
293 	db_expr_t	addr;
294 	boolean_t	have_addr;
295 	db_expr_t	count;
296 	char *		modif;
297 {
298 	if (count == -1)
299 	    count = 1;
300 
301 	db_set_breakpoint(db_map_addr(addr), (db_addr_t)addr, count);
302 }
303 
304 /* list breakpoints */
305 void
306 db_listbreak_cmd(dummy1, dummy2, dummy3, dummy4)
307 	db_expr_t	dummy1;
308 	boolean_t	dummy2;
309 	db_expr_t	dummy3;
310 	char *		dummy4;
311 {
312 	db_list_breakpoints();
313 }
314 
315 /*
316  *	We want ddb to be usable before most of the kernel has been
317  *	initialized.  In particular, current_thread() or kernel_map
318  *	(or both) may be null.
319  */
320 
321 boolean_t
322 db_map_equal(map1, map2)
323 	vm_map_t	map1, map2;
324 {
325 	return ((map1 == map2) ||
326 		((map1 == NULL) && (map2 == kernel_map)) ||
327 		((map1 == kernel_map) && (map2 == NULL)));
328 }
329 
330 boolean_t
331 db_map_current(map)
332 	vm_map_t	map;
333 {
334 #if 0
335 	thread_t	thread;
336 
337 	return ((map == NULL) ||
338 		(map == kernel_map) ||
339 		(((thread = current_thread()) != NULL) &&
340 		 (map == thread->task->map)));
341 #else
342 	return (1);
343 #endif
344 }
345 
346 vm_map_t
347 db_map_addr(addr)
348 	vm_offset_t addr;
349 {
350 #if 0
351 	thread_t	thread;
352 
353 	/*
354 	 *	We want to return kernel_map for all
355 	 *	non-user addresses, even when debugging
356 	 *	kernel tasks with their own maps.
357 	 */
358 
359 	if ((VM_MIN_ADDRESS <= addr) &&
360 	    (addr < VM_MAX_ADDRESS) &&
361 	    ((thread = current_thread()) != NULL))
362 	    return thread->task->map;
363 	else
364 #endif
365 	    return kernel_map;
366 }
367