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 } 344