db_break.c revision 623 
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 *	$Id$
27 */
28
29/*
30 *	Author: David B. Golub, Carnegie Mellon University
31 *	Date:	7/90
32 */
33/*
34 * Breakpoints.
35 */
36#include "param.h"
37#include "proc.h"
38#include <machine/db_machdep.h>		/* type definitions */
39
40#include <ddb/db_lex.h>
41#include <ddb/db_break.h>
42#include <ddb/db_access.h>
43#include <ddb/db_sym.h>
44#include <ddb/db_break.h>
45
46extern boolean_t db_map_equal();
47extern boolean_t db_map_current();
48extern vm_map_t db_map_addr();
49
50#define	NBREAKPOINTS	100
51struct db_breakpoint	db_break_table[NBREAKPOINTS];
52db_breakpoint_t		db_next_free_breakpoint = &db_break_table[0];
53db_breakpoint_t		db_free_breakpoints = 0;
54db_breakpoint_t		db_breakpoint_list = 0;
55
56db_breakpoint_t
57db_breakpoint_alloc()
58{
59	register db_breakpoint_t	bkpt;
60
61	if ((bkpt = db_free_breakpoints) != 0) {
62	    db_free_breakpoints = bkpt->link;
63	    return (bkpt);
64	}
65	if (db_next_free_breakpoint == &db_break_table[NBREAKPOINTS]) {
66	    db_printf("All breakpoints used.\n");
67	    return (0);
68	}
69	bkpt = db_next_free_breakpoint;
70	db_next_free_breakpoint++;
71
72	return (bkpt);
73}
74
75void
76db_breakpoint_free(bkpt)
77	register db_breakpoint_t	bkpt;
78{
79	bkpt->link = db_free_breakpoints;
80	db_free_breakpoints = bkpt;
81}
82
83void
84db_set_breakpoint(map, addr, count)
85	vm_map_t	map;
86	db_addr_t	addr;
87	int		count;
88{
89	register db_breakpoint_t	bkpt;
90
91	if (db_find_breakpoint(map, addr)) {
92	    db_printf("Already set.\n");
93	    return;
94	}
95
96	bkpt = db_breakpoint_alloc();
97	if (bkpt == 0) {
98	    db_printf("Too many breakpoints.\n");
99	    return;
100	}
101
102	bkpt->map = map;
103	bkpt->address = addr;
104	bkpt->flags = 0;
105	bkpt->init_count = count;
106	bkpt->count = count;
107
108	bkpt->link = db_breakpoint_list;
109	db_breakpoint_list = bkpt;
110}
111
112void
113db_delete_breakpoint(map, addr)
114	vm_map_t	map;
115	db_addr_t	addr;
116{
117	register db_breakpoint_t	bkpt;
118	register db_breakpoint_t	*prev;
119
120	for (prev = &db_breakpoint_list;
121	     (bkpt = *prev) != 0;
122	     prev = &bkpt->link) {
123	    if (db_map_equal(bkpt->map, map) &&
124		(bkpt->address == addr)) {
125		*prev = bkpt->link;
126		break;
127	    }
128	}
129	if (bkpt == 0) {
130	    db_printf("Not set.\n");
131	    return;
132	}
133
134	db_breakpoint_free(bkpt);
135}
136
137db_breakpoint_t
138db_find_breakpoint(map, addr)
139	vm_map_t	map;
140	db_addr_t	addr;
141{
142	register db_breakpoint_t	bkpt;
143
144	for (bkpt = db_breakpoint_list;
145	     bkpt != 0;
146	     bkpt = bkpt->link)
147	{
148	    if (db_map_equal(bkpt->map, map) &&
149		(bkpt->address == addr))
150		return (bkpt);
151	}
152	return (0);
153}
154
155db_breakpoint_t
156db_find_breakpoint_here(addr)
157	db_addr_t	addr;
158{
159    return db_find_breakpoint(db_map_addr(addr), addr);
160}
161
162boolean_t	db_breakpoints_inserted = TRUE;
163
164void
165db_set_breakpoints()
166{
167	register db_breakpoint_t	bkpt;
168
169	if (!db_breakpoints_inserted) {
170
171	    for (bkpt = db_breakpoint_list;
172	         bkpt != 0;
173	         bkpt = bkpt->link)
174		if (db_map_current(bkpt->map)) {
175		    bkpt->bkpt_inst = db_get_value(bkpt->address,
176						   BKPT_SIZE,
177						   FALSE);
178		    db_put_value(bkpt->address,
179				 BKPT_SIZE,
180				 BKPT_SET(bkpt->bkpt_inst));
181		}
182	    db_breakpoints_inserted = TRUE;
183	}
184}
185
186void
187db_clear_breakpoints()
188{
189	register db_breakpoint_t	bkpt;
190
191	if (db_breakpoints_inserted) {
192
193	    for (bkpt = db_breakpoint_list;
194	         bkpt != 0;
195		 bkpt = bkpt->link)
196		if (db_map_current(bkpt->map)) {
197		    db_put_value(bkpt->address, BKPT_SIZE, bkpt->bkpt_inst);
198		}
199	    db_breakpoints_inserted = FALSE;
200	}
201}
202
203/*
204 * Set a temporary breakpoint.
205 * The instruction is changed immediately,
206 * so the breakpoint does not have to be on the breakpoint list.
207 */
208db_breakpoint_t
209db_set_temp_breakpoint(addr)
210	db_addr_t	addr;
211{
212	register db_breakpoint_t	bkpt;
213
214	bkpt = db_breakpoint_alloc();
215	if (bkpt == 0) {
216	    db_printf("Too many breakpoints.\n");
217	    return 0;
218	}
219
220	bkpt->map = NULL;
221	bkpt->address = addr;
222	bkpt->flags = BKPT_TEMP;
223	bkpt->init_count = 1;
224	bkpt->count = 1;
225
226	bkpt->bkpt_inst = db_get_value(bkpt->address, BKPT_SIZE, FALSE);
227	db_put_value(bkpt->address, BKPT_SIZE, BKPT_SET(bkpt->bkpt_inst));
228	return bkpt;
229}
230
231void
232db_delete_temp_breakpoint(bkpt)
233	db_breakpoint_t	bkpt;
234{
235	db_put_value(bkpt->address, BKPT_SIZE, bkpt->bkpt_inst);
236	db_breakpoint_free(bkpt);
237}
238
239/*
240 * List breakpoints.
241 */
242void
243db_list_breakpoints()
244{
245	register db_breakpoint_t	bkpt;
246
247	if (db_breakpoint_list == 0) {
248	    db_printf("No breakpoints set\n");
249	    return;
250	}
251
252	db_printf(" Map      Count    Address\n");
253	for (bkpt = db_breakpoint_list;
254	     bkpt != 0;
255	     bkpt = bkpt->link)
256	{
257	    db_printf("%s%8x %5d    ",
258		      db_map_current(bkpt->map) ? "*" : " ",
259		      bkpt->map, bkpt->init_count);
260	    db_printsym(bkpt->address, DB_STGY_PROC);
261	    db_printf("\n");
262	}
263}
264
265/* Delete breakpoint */
266/*ARGSUSED*/
267void
268db_delete_cmd(addr, have_addr, count, modif)
269	db_expr_t	addr;
270	int		have_addr;
271	db_expr_t	count;
272	char *		modif;
273{
274	db_delete_breakpoint(db_map_addr(addr), (db_addr_t)addr);
275}
276
277/* Set breakpoint with skip count */
278/*ARGSUSED*/
279void
280db_breakpoint_cmd(addr, have_addr, count, modif)
281	db_expr_t	addr;
282	int		have_addr;
283	db_expr_t	count;
284	char *		modif;
285{
286	if (count == -1)
287	    count = 1;
288
289	db_set_breakpoint(db_map_addr(addr), (db_addr_t)addr, count);
290}
291
292/* list breakpoints */
293void
294db_listbreak_cmd()
295{
296	db_list_breakpoints();
297}
298
299#include <vm/vm_kern.h>
300
301/*
302 *	We want ddb to be usable before most of the kernel has been
303 *	initialized.  In particular, current_thread() or kernel_map
304 *	(or both) may be null.
305 */
306
307boolean_t
308db_map_equal(map1, map2)
309	vm_map_t	map1, map2;
310{
311	return ((map1 == map2) ||
312		((map1 == NULL) && (map2 == kernel_map)) ||
313		((map1 == kernel_map) && (map2 == NULL)));
314}
315
316boolean_t
317db_map_current(map)
318	vm_map_t	map;
319{
320#if 0
321	thread_t	thread;
322
323	return ((map == NULL) ||
324		(map == kernel_map) ||
325		(((thread = current_thread()) != NULL) &&
326		 (map == thread->task->map)));
327#else
328	return (1);
329#endif
330}
331
332vm_map_t
333db_map_addr(addr)
334	vm_offset_t addr;
335{
336#if 0
337	thread_t	thread;
338
339	/*
340	 *	We want to return kernel_map for all
341	 *	non-user addresses, even when debugging
342	 *	kernel tasks with their own maps.
343	 */
344
345	if ((VM_MIN_ADDRESS <= addr) &&
346	    (addr < VM_MAX_ADDRESS) &&
347	    ((thread = current_thread()) != NULL))
348	    return thread->task->map;
349	else
350#endif
351	    return kernel_map;
352}
353