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  * $FreeBSD: src/sys/ddb/db_break.c,v 1.18 1999/08/28 00:41:05 peter Exp $
  27  * $DragonFly: src/sys/ddb/db_break.c,v 1.4 2003/08/27 10:47:13 rob Exp $
  28  */
  29
  30 /*
  31  *      Author: David B. Golub, Carnegie Mellon University
  32  *      Date:   7/90
  33  */
  34 /*
  35  * Breakpoints.
  36  */
  37 #include <sys/param.h>
  38
  39 #include <vm/vm.h>
  40 #include <vm/vm_kern.h>
  41
  42 #include <ddb/ddb.h>
  43 #include <ddb/db_break.h>
  44 #include <ddb/db_access.h>
  45 #include <ddb/db_sym.h>
  46
  47 #define NBREAKPOINTS    100
  48 static struct db_breakpoint     db_break_table[NBREAKPOINTS];
  49 static db_breakpoint_t          db_next_free_breakpoint = &db_break_table[0];
  50 static db_breakpoint_t          db_free_breakpoints = 0;
  51 static db_breakpoint_t          db_breakpoint_list = 0;
  52
  53 static db_breakpoint_t  db_breakpoint_alloc (void);
  54 static void     db_breakpoint_free (db_breakpoint_t bkpt);
  55 static void     db_delete_breakpoint (vm_map_t map, db_addr_t addr);
  56 static db_breakpoint_t  db_find_breakpoint (vm_map_t map, db_addr_t addr);
  57 static void     db_list_breakpoints (void);
  58 static void     db_set_breakpoint (vm_map_t map, db_addr_t addr,
  59                                        int count);
  60
  61 static db_breakpoint_t
  62 db_breakpoint_alloc()
  63 {
  64         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         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         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         db_breakpoint_t bkpt;
 123         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         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 void
 170 db_set_breakpoints()
 171 {
 172         db_breakpoint_t bkpt;
 173
 174         if (!db_breakpoints_inserted) {
 175
 176             for (bkpt = db_breakpoint_list;
 177                  bkpt != 0;
 178                  bkpt = bkpt->link)
 179                 if (db_map_current(bkpt->map)) {
 180                     bkpt->bkpt_inst = db_get_value(bkpt->address,
 181                                                    BKPT_SIZE,
 182                                                    FALSE);
 183                     db_put_value(bkpt->address,
 184                                  BKPT_SIZE,
 185                                  BKPT_SET(bkpt->bkpt_inst));
 186                 }
 187             db_breakpoints_inserted = TRUE;
 188         }
 189 }
 190
 191 void
 192 db_clear_breakpoints()
 193 {
 194         db_breakpoint_t bkpt;
 195
 196         if (db_breakpoints_inserted) {
 197
 198             for (bkpt = db_breakpoint_list;
 199                  bkpt != 0;
 200                  bkpt = bkpt->link)
 201                 if (db_map_current(bkpt->map)) {
 202                     db_put_value(bkpt->address, BKPT_SIZE, bkpt->bkpt_inst);
 203                 }
 204             db_breakpoints_inserted = FALSE;
 205         }
 206 }
 207
 208 #ifdef SOFTWARE_SSTEP
 209 /*
 210  * Set a temporary breakpoint.
 211  * The instruction is changed immediately,
 212  * so the breakpoint does not have to be on the breakpoint list.
 213  */
 214 db_breakpoint_t
 215 db_set_temp_breakpoint(addr)
 216         db_addr_t       addr;
 217 {
 218         db_breakpoint_t bkpt;
 219
 220         bkpt = db_breakpoint_alloc();
 221         if (bkpt == 0) {
 222             db_printf("Too many breakpoints.\n");
 223             return 0;
 224         }
 225
 226         bkpt->map = NULL;
 227         bkpt->address = addr;
 228         bkpt->flags = BKPT_TEMP;
 229         bkpt->init_count = 1;
 230         bkpt->count = 1;
 231
 232         bkpt->bkpt_inst = db_get_value(bkpt->address, BKPT_SIZE, FALSE);
 233         db_put_value(bkpt->address, BKPT_SIZE, BKPT_SET(bkpt->bkpt_inst));
 234         return bkpt;
 235 }
 236
 237 void
 238 db_delete_temp_breakpoint(bkpt)
 239         db_breakpoint_t bkpt;
 240 {
 241         db_put_value(bkpt->address, BKPT_SIZE, bkpt->bkpt_inst);
 242         db_breakpoint_free(bkpt);
 243 }
 244 #endif /* SOFTWARE_SSTEP */
 245
 246 /*
 247  * List breakpoints.
 248  */
 249 static void
 250 db_list_breakpoints()
 251 {
 252         db_breakpoint_t bkpt;
 253
 254         if (db_breakpoint_list == 0) {
 255             db_printf("No breakpoints set\n");
 256             return;
 257         }
 258
 259         db_printf(" Map      Count    Address\n");
 260         for (bkpt = db_breakpoint_list;
 261              bkpt != 0;
 262              bkpt = bkpt->link) {
 263             db_printf("%s%8p %5d    ",
 264                       db_map_current(bkpt->map) ? "*" : " ",
 265                       (void *)bkpt->map, bkpt->init_count);
 266             db_printsym(bkpt->address, DB_STGY_PROC);
 267             db_printf("\n");
 268         }
 269 }
 270
 271 /* Delete breakpoint */
 272 /*ARGSUSED*/
 273 void
 274 db_delete_cmd(addr, have_addr, count, modif)
 275         db_expr_t       addr;
 276         boolean_t       have_addr;
 277         db_expr_t       count;
 278         char *          modif;
 279 {
 280         db_delete_breakpoint(db_map_addr(addr), (db_addr_t)addr);
 281 }
 282
 283 /* Set breakpoint with skip count */
 284 /*ARGSUSED*/
 285 void
 286 db_breakpoint_cmd(addr, have_addr, count, modif)
 287         db_expr_t       addr;
 288         boolean_t       have_addr;
 289         db_expr_t       count;
 290         char *          modif;
 291 {
 292         if (count == -1)
 293             count = 1;
 294
 295         db_set_breakpoint(db_map_addr(addr), (db_addr_t)addr, count);
 296 }
 297
 298 /* list breakpoints */
 299 void
 300 db_listbreak_cmd(dummy1, dummy2, dummy3, dummy4)
 301         db_expr_t       dummy1;
 302         boolean_t       dummy2;
 303         db_expr_t       dummy3;
 304         char *          dummy4;
 305 {
 306         db_list_breakpoints();
 307 }
 308
 309 /*
 310  *      We want ddb to be usable before most of the kernel has been
 311  *      initialized.  In particular, current_thread() or kernel_map
 312  *      (or both) may be null.
 313  */
 314
 315 boolean_t
 316 db_map_equal(map1, map2)
 317         vm_map_t        map1, map2;
 318 {
 319         return ((map1 == map2) ||
 320                 ((map1 == NULL) && (map2 == kernel_map)) ||
 321                 ((map1 == kernel_map) && (map2 == NULL)));
 322 }
 323
 324 boolean_t
 325 db_map_current(map)
 326         vm_map_t        map;
 327 {
 328 #if 0
 329         thread_t        thread;
 330
 331         return ((map == NULL) ||
 332                 (map == kernel_map) ||
 333                 (((thread = current_thread()) != NULL) &&
 334                  (map == thread->task->map)));
 335 #else
 336         return (1);
 337 #endif
 338 }
 339
 340 vm_map_t
 341 db_map_addr(addr)
 342         vm_offset_t addr;
 343 {
 344 #if 0
 345         thread_t        thread;
 346
 347         /*
 348          *      We want to return kernel_map for all
 349          *      non-user addresses, even when debugging
 350          *      kernel tasks with their own maps.
 351          */
 352
 353         if ((VM_MIN_ADDRESS <= addr) &&
 354             (addr < VM_MAX_ADDRESS) &&
 355             ((thread = current_thread()) != NULL))
 356             return thread->task->map;
 357         else
 358 #endif
 359             return kernel_map;
 360 }