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_watch.c,v 1.20.2.1 2001/07/25 01:00:08 bsd Exp $ 27 * $DragonFly: src/sys/ddb/db_watch.c,v 1.4 2003/08/27 10:47:13 rob Exp $ 28 */ 29 30 /* 31 * Author: Richard P. Draves, Carnegie Mellon University 32 * Date: 10/90 33 */ 34 35 #include <sys/param.h> 36 #include <sys/kernel.h> 37 38 #include <vm/vm.h> 39 #include <sys/lock.h> 40 #include <vm/pmap.h> 41 #include <vm/vm_map.h> 42 43 #include <ddb/ddb.h> 44 #include <ddb/db_watch.h> 45 46 /* 47 * Watchpoints. 48 */ 49 50 static boolean_t db_watchpoints_inserted = TRUE; 51 52 #define NWATCHPOINTS 100 53 static struct db_watchpoint db_watch_table[NWATCHPOINTS]; 54 static db_watchpoint_t db_next_free_watchpoint = &db_watch_table[0]; 55 static db_watchpoint_t db_free_watchpoints = 0; 56 static db_watchpoint_t db_watchpoint_list = 0; 57 58 static db_watchpoint_t db_watchpoint_alloc (void); 59 static void db_watchpoint_free (db_watchpoint_t watch); 60 static void db_delete_watchpoint (vm_map_t map, 61 db_addr_t addr); 62 #ifdef notused 63 static boolean_t db_find_watchpoint (vm_map_t map, db_addr_t addr, 64 db_regs_t *regs); 65 #endif 66 static void db_list_watchpoints (void); 67 static void db_set_watchpoint (vm_map_t map, db_addr_t addr, 68 vm_size_t size); 69 70 int db_md_set_watchpoint (db_expr_t addr, db_expr_t size); 71 int db_md_clr_watchpoint (db_expr_t addr, db_expr_t size); 72 void db_md_list_watchpoints (void); 73 74 75 db_watchpoint_t 76 db_watchpoint_alloc() 77 { 78 db_watchpoint_t watch; 79 80 if ((watch = db_free_watchpoints) != 0) { 81 db_free_watchpoints = watch->link; 82 return (watch); 83 } 84 if (db_next_free_watchpoint == &db_watch_table[NWATCHPOINTS]) { 85 db_printf("All watchpoints used.\n"); 86 return (0); 87 } 88 watch = db_next_free_watchpoint; 89 db_next_free_watchpoint++; 90 91 return (watch); 92 } 93 94 void 95 db_watchpoint_free(watch) 96 db_watchpoint_t watch; 97 { 98 watch->link = db_free_watchpoints; 99 db_free_watchpoints = watch; 100 } 101 102 static void 103 db_set_watchpoint(map, addr, size) 104 vm_map_t map; 105 db_addr_t addr; 106 vm_size_t size; 107 { 108 db_watchpoint_t watch; 109 110 if (map == NULL) { 111 db_printf("No map.\n"); 112 return; 113 } 114 115 /* 116 * Should we do anything fancy with overlapping regions? 117 */ 118 119 for (watch = db_watchpoint_list; 120 watch != 0; 121 watch = watch->link) 122 if (db_map_equal(watch->map, map) && 123 (watch->loaddr == addr) && 124 (watch->hiaddr == addr+size)) { 125 db_printf("Already set.\n"); 126 return; 127 } 128 129 watch = db_watchpoint_alloc(); 130 if (watch == 0) { 131 db_printf("Too many watchpoints.\n"); 132 return; 133 } 134 135 watch->map = map; 136 watch->loaddr = addr; 137 watch->hiaddr = addr+size; 138 139 watch->link = db_watchpoint_list; 140 db_watchpoint_list = watch; 141 142 db_watchpoints_inserted = FALSE; 143 } 144 145 static void 146 db_delete_watchpoint(map, addr) 147 vm_map_t map; 148 db_addr_t addr; 149 { 150 db_watchpoint_t watch; 151 db_watchpoint_t *prev; 152 153 for (prev = &db_watchpoint_list; 154 (watch = *prev) != 0; 155 prev = &watch->link) 156 if (db_map_equal(watch->map, map) && 157 (watch->loaddr <= addr) && 158 (addr < watch->hiaddr)) { 159 *prev = watch->link; 160 db_watchpoint_free(watch); 161 return; 162 } 163 164 db_printf("Not set.\n"); 165 } 166 167 static void 168 db_list_watchpoints() 169 { 170 db_watchpoint_t watch; 171 172 if (db_watchpoint_list == 0) { 173 db_printf("No watchpoints set\n"); 174 return; 175 } 176 177 db_printf(" Map Address Size\n"); 178 for (watch = db_watchpoint_list; 179 watch != 0; 180 watch = watch->link) 181 db_printf("%s%8p %8lx %lx\n", 182 db_map_current(watch->map) ? "*" : " ", 183 (void *)watch->map, (long)watch->loaddr, 184 (long)watch->hiaddr - (long)watch->loaddr); 185 } 186 187 /* Delete watchpoint */ 188 /*ARGSUSED*/ 189 void 190 db_deletewatch_cmd(addr, have_addr, count, modif) 191 db_expr_t addr; 192 boolean_t have_addr; 193 db_expr_t count; 194 char * modif; 195 { 196 db_delete_watchpoint(db_map_addr(addr), addr); 197 } 198 199 /* Set watchpoint */ 200 /*ARGSUSED*/ 201 void 202 db_watchpoint_cmd(addr, have_addr, count, modif) 203 db_expr_t addr; 204 boolean_t have_addr; 205 db_expr_t count; 206 char * modif; 207 { 208 vm_size_t size; 209 db_expr_t value; 210 211 if (db_expression(&value)) 212 size = (vm_size_t) value; 213 else 214 size = 4; 215 db_skip_to_eol(); 216 217 db_set_watchpoint(db_map_addr(addr), addr, size); 218 } 219 220 /* 221 * At least one non-optional show-command must be implemented using 222 * DB_SHOW_COMMAND() so that db_show_cmd_set gets created. Here is one. 223 */ 224 DB_SHOW_COMMAND(watches, db_listwatch_cmd) 225 { 226 db_list_watchpoints(); 227 db_md_list_watchpoints(); 228 } 229 230 void 231 db_set_watchpoints() 232 { 233 db_watchpoint_t watch; 234 235 if (!db_watchpoints_inserted) { 236 for (watch = db_watchpoint_list; 237 watch != 0; 238 watch = watch->link) 239 pmap_protect(watch->map->pmap, 240 trunc_page(watch->loaddr), 241 round_page(watch->hiaddr), 242 VM_PROT_READ); 243 244 db_watchpoints_inserted = TRUE; 245 } 246 } 247 248 void 249 db_clear_watchpoints() 250 { 251 db_watchpoints_inserted = FALSE; 252 } 253 254 #ifdef notused 255 static boolean_t 256 db_find_watchpoint(map, addr, regs) 257 vm_map_t map; 258 db_addr_t addr; 259 db_regs_t *regs; 260 { 261 db_watchpoint_t watch; 262 db_watchpoint_t found = 0; 263 264 for (watch = db_watchpoint_list; 265 watch != 0; 266 watch = watch->link) 267 if (db_map_equal(watch->map, map)) { 268 if ((watch->loaddr <= addr) && 269 (addr < watch->hiaddr)) 270 return (TRUE); 271 else if ((trunc_page(watch->loaddr) <= addr) && 272 (addr < round_page(watch->hiaddr))) 273 found = watch; 274 } 275 276 /* 277 * We didn't hit exactly on a watchpoint, but we are 278 * in a protected region. We want to single-step 279 * and then re-protect. 280 */ 281 282 if (found) { 283 db_watchpoints_inserted = FALSE; 284 db_single_step(regs); 285 } 286 287 return (FALSE); 288 } 289 #endif 290 291 292 293 /* Delete hardware watchpoint */ 294 /*ARGSUSED*/ 295 void 296 db_deletehwatch_cmd(addr, have_addr, count, modif) 297 db_expr_t addr; 298 boolean_t have_addr; 299 db_expr_t count; 300 char * modif; 301 { 302 int rc; 303 304 if (count < 0) 305 count = 4; 306 307 rc = db_md_clr_watchpoint(addr, count); 308 if (rc < 0) 309 db_printf("hardware watchpoint could not be deleted\n"); 310 } 311 312 /* Set hardware watchpoint */ 313 /*ARGSUSED*/ 314 void 315 db_hwatchpoint_cmd(addr, have_addr, count, modif) 316 db_expr_t addr; 317 boolean_t have_addr; 318 db_expr_t count; 319 char * modif; 320 { 321 int rc; 322 323 if (count < 0) 324 count = 4; 325 326 rc = db_md_set_watchpoint(addr, count); 327 if (rc < 0) 328 db_printf("hardware watchpoint could not be set\n"); 329 } 330