xref: /freebsd/sys/ddb/db_break.c (revision 10b59a9b4add0320d52c15ce057dd697261e7dfc)
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("$FreeBSD$");
37  
38  #include <sys/param.h>
39  
40  #include <vm/vm.h>
41  #include <vm/vm_kern.h>
42  
43  #include <ddb/ddb.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(void);
55  static void	db_breakpoint_free(db_breakpoint_t bkpt);
56  static void	db_delete_breakpoint(vm_map_t map, db_addr_t addr);
57  static db_breakpoint_t	db_find_breakpoint(vm_map_t map, db_addr_t addr);
58  static void	db_list_breakpoints(void);
59  static void	db_set_breakpoint(vm_map_t map, db_addr_t addr, int count);
60  
61  static db_breakpoint_t
62  db_breakpoint_alloc()
63  {
64  	register db_breakpoint_t	bkpt;
65  
66  	if ((bkpt = db_free_breakpoints) != 0) {
67  	    db_free_breakpoints = bkpt->link;
68  	    return (bkpt);
69  	}
70  	if (db_next_free_breakpoint == &db_break_table[NBREAKPOINTS]) {
71  	    db_printf("All breakpoints used.\n");
72  	    return (0);
73  	}
74  	bkpt = db_next_free_breakpoint;
75  	db_next_free_breakpoint++;
76  
77  	return (bkpt);
78  }
79  
80  static void
81  db_breakpoint_free(bkpt)
82  	register db_breakpoint_t	bkpt;
83  {
84  	bkpt->link = db_free_breakpoints;
85  	db_free_breakpoints = bkpt;
86  }
87  
88  static void
89  db_set_breakpoint(map, addr, count)
90  	vm_map_t	map;
91  	db_addr_t	addr;
92  	int		count;
93  {
94  	register db_breakpoint_t	bkpt;
95  
96  	if (db_find_breakpoint(map, addr)) {
97  	    db_printf("Already set.\n");
98  	    return;
99  	}
100  
101  	bkpt = db_breakpoint_alloc();
102  	if (bkpt == 0) {
103  	    db_printf("Too many breakpoints.\n");
104  	    return;
105  	}
106  
107  	bkpt->map = map;
108  	bkpt->address = addr;
109  	bkpt->flags = 0;
110  	bkpt->init_count = count;
111  	bkpt->count = count;
112  
113  	bkpt->link = db_breakpoint_list;
114  	db_breakpoint_list = bkpt;
115  }
116  
117  static void
118  db_delete_breakpoint(map, addr)
119  	vm_map_t	map;
120  	db_addr_t	addr;
121  {
122  	register db_breakpoint_t	bkpt;
123  	register db_breakpoint_t	*prev;
124  
125  	for (prev = &db_breakpoint_list;
126  	     (bkpt = *prev) != 0;
127  	     prev = &bkpt->link) {
128  	    if (db_map_equal(bkpt->map, map) &&
129  		(bkpt->address == addr)) {
130  		*prev = bkpt->link;
131  		break;
132  	    }
133  	}
134  	if (bkpt == 0) {
135  	    db_printf("Not set.\n");
136  	    return;
137  	}
138  
139  	db_breakpoint_free(bkpt);
140  }
141  
142  static db_breakpoint_t
143  db_find_breakpoint(map, addr)
144  	vm_map_t	map;
145  	db_addr_t	addr;
146  {
147  	register db_breakpoint_t	bkpt;
148  
149  	for (bkpt = db_breakpoint_list;
150  	     bkpt != 0;
151  	     bkpt = bkpt->link)
152  	{
153  	    if (db_map_equal(bkpt->map, map) &&
154  		(bkpt->address == addr))
155  		return (bkpt);
156  	}
157  	return (0);
158  }
159  
160  db_breakpoint_t
161  db_find_breakpoint_here(addr)
162  	db_addr_t	addr;
163  {
164      return db_find_breakpoint(db_map_addr(addr), addr);
165  }
166  
167  static boolean_t	db_breakpoints_inserted = TRUE;
168  
169  #ifndef BKPT_WRITE
170  #define BKPT_WRITE(addr, storage)				\
171  do {								\
172  	*storage = db_get_value(addr, BKPT_SIZE, FALSE);	\
173  	db_put_value(addr, BKPT_SIZE, BKPT_SET(*storage));	\
174  } while (0)
175  #endif
176  
177  #ifndef BKPT_CLEAR
178  #define BKPT_CLEAR(addr, storage) \
179  	db_put_value(addr, BKPT_SIZE, *storage)
180  #endif
181  
182  void
183  db_set_breakpoints()
184  {
185  	register db_breakpoint_t	bkpt;
186  
187  	if (!db_breakpoints_inserted) {
188  
189  		for (bkpt = db_breakpoint_list;
190  		     bkpt != 0;
191  		     bkpt = bkpt->link)
192  			if (db_map_current(bkpt->map)) {
193  				BKPT_WRITE(bkpt->address, &bkpt->bkpt_inst);
194  			}
195  		db_breakpoints_inserted = TRUE;
196  	}
197  }
198  
199  void
200  db_clear_breakpoints()
201  {
202  	register db_breakpoint_t	bkpt;
203  
204  	if (db_breakpoints_inserted) {
205  
206  		for (bkpt = db_breakpoint_list;
207  		     bkpt != 0;
208  		     bkpt = bkpt->link)
209  			if (db_map_current(bkpt->map)) {
210  				BKPT_CLEAR(bkpt->address, &bkpt->bkpt_inst);
211  			}
212  		db_breakpoints_inserted = FALSE;
213  	}
214  }
215  
216  #ifdef SOFTWARE_SSTEP
217  /*
218   * Set a temporary breakpoint.
219   * The instruction is changed immediately,
220   * so the breakpoint does not have to be on the breakpoint list.
221   */
222  db_breakpoint_t
223  db_set_temp_breakpoint(addr)
224  	db_addr_t	addr;
225  {
226  	register db_breakpoint_t	bkpt;
227  
228  	bkpt = db_breakpoint_alloc();
229  	if (bkpt == 0) {
230  	    db_printf("Too many breakpoints.\n");
231  	    return 0;
232  	}
233  
234  	bkpt->map = NULL;
235  	bkpt->address = addr;
236  	bkpt->flags = BKPT_TEMP;
237  	bkpt->init_count = 1;
238  	bkpt->count = 1;
239  
240  	BKPT_WRITE(bkpt->address, &bkpt->bkpt_inst);
241  	return bkpt;
242  }
243  
244  void
245  db_delete_temp_breakpoint(bkpt)
246  	db_breakpoint_t	bkpt;
247  {
248  	BKPT_CLEAR(bkpt->address, &bkpt->bkpt_inst);
249  	db_breakpoint_free(bkpt);
250  }
251  #endif /* SOFTWARE_SSTEP */
252  
253  /*
254   * List breakpoints.
255   */
256  static void
257  db_list_breakpoints()
258  {
259  	register db_breakpoint_t	bkpt;
260  
261  	if (db_breakpoint_list == 0) {
262  	    db_printf("No breakpoints set\n");
263  	    return;
264  	}
265  
266  	db_printf(" Map      Count    Address\n");
267  	for (bkpt = db_breakpoint_list;
268  	     bkpt != 0;
269  	     bkpt = bkpt->link) {
270  	    db_printf("%s%8p %5d    ",
271  		      db_map_current(bkpt->map) ? "*" : " ",
272  		      (void *)bkpt->map, bkpt->init_count);
273  	    db_printsym(bkpt->address, DB_STGY_PROC);
274  	    db_printf("\n");
275  	}
276  }
277  
278  /* Delete breakpoint */
279  /*ARGSUSED*/
280  void
281  db_delete_cmd(addr, have_addr, count, modif)
282  	db_expr_t	addr;
283  	boolean_t	have_addr;
284  	db_expr_t	count;
285  	char *		modif;
286  {
287  	db_delete_breakpoint(db_map_addr(addr), (db_addr_t)addr);
288  }
289  
290  /* Set breakpoint with skip count */
291  /*ARGSUSED*/
292  void
293  db_breakpoint_cmd(addr, have_addr, count, modif)
294  	db_expr_t	addr;
295  	boolean_t	have_addr;
296  	db_expr_t	count;
297  	char *		modif;
298  {
299  	if (count == -1)
300  	    count = 1;
301  
302  	db_set_breakpoint(db_map_addr(addr), (db_addr_t)addr, count);
303  }
304  
305  /* list breakpoints */
306  void
307  db_listbreak_cmd(dummy1, dummy2, dummy3, dummy4)
308  	db_expr_t	dummy1;
309  	boolean_t	dummy2;
310  	db_expr_t	dummy3;
311  	char *		dummy4;
312  {
313  	db_list_breakpoints();
314  }
315  
316  /*
317   *	We want ddb to be usable before most of the kernel has been
318   *	initialized.  In particular, current_thread() or kernel_map
319   *	(or both) may be null.
320   */
321  
322  boolean_t
323  db_map_equal(map1, map2)
324  	vm_map_t	map1, map2;
325  {
326  	return ((map1 == map2) ||
327  		((map1 == NULL) && (map2 == kernel_map)) ||
328  		((map1 == kernel_map) && (map2 == NULL)));
329  }
330  
331  boolean_t
332  db_map_current(map)
333  	vm_map_t	map;
334  {
335  #if 0
336  	thread_t	thread;
337  
338  	return ((map == NULL) ||
339  		(map == kernel_map) ||
340  		(((thread = current_thread()) != NULL) &&
341  		 (map == thread->task->map)));
342  #else
343  	return (1);
344  #endif
345  }
346  
347  vm_map_t
348  db_map_addr(addr)
349  	vm_offset_t addr;
350  {
351  #if 0
352  	thread_t	thread;
353  
354  	/*
355  	 *	We want to return kernel_map for all
356  	 *	non-user addresses, even when debugging
357  	 *	kernel tasks with their own maps.
358  	 */
359  
360  	if ((VM_MIN_ADDRESS <= addr) &&
361  	    (addr < VM_MAX_ADDRESS) &&
362  	    ((thread = current_thread()) != NULL))
363  	    return thread->task->map;
364  	else
365  #endif
366  	    return kernel_map;
367  }
368