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