1 /* $NetBSD: db_watch.c,v 1.18 2001/11/12 22:54:07 lukem Exp $ */ 2 3 /* 4 * Mach Operating System 5 * Copyright (c) 1991,1990 Carnegie Mellon University 6 * All Rights Reserved. 7 * 8 * Permission to use, copy, modify and distribute this software and its 9 * documentation is hereby granted, provided that both the copyright 10 * notice and this permission notice appear in all copies of the 11 * software, derivative works or modified versions, and any portions 12 * thereof, and that both notices appear in supporting documentation. 13 * 14 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 15 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR 16 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 17 * 18 * Carnegie Mellon requests users of this software to return to 19 * 20 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 21 * School of Computer Science 22 * Carnegie Mellon University 23 * Pittsburgh PA 15213-3890 24 * 25 * any improvements or extensions that they make and grant Carnegie the 26 * rights to redistribute these changes. 27 * 28 * Author: Richard P. Draves, Carnegie Mellon University 29 * Date: 10/90 30 */ 31 32 #include <sys/cdefs.h> 33 __KERNEL_RCSID(0, "$NetBSD: db_watch.c,v 1.18 2001/11/12 22:54:07 lukem Exp $"); 34 35 #include <sys/param.h> 36 #include <sys/proc.h> 37 38 #include <machine/db_machdep.h> 39 40 #include <ddb/db_break.h> 41 #include <ddb/db_watch.h> 42 #include <ddb/db_lex.h> 43 #include <ddb/db_access.h> 44 #include <ddb/db_run.h> 45 #include <ddb/db_sym.h> 46 #include <ddb/db_output.h> 47 #include <ddb/db_command.h> 48 #include <ddb/db_extern.h> 49 50 /* 51 * Watchpoints. 52 */ 53 54 boolean_t db_watchpoints_inserted = TRUE; 55 56 #define NWATCHPOINTS 100 57 struct db_watchpoint db_watch_table[NWATCHPOINTS]; 58 db_watchpoint_t db_next_free_watchpoint = &db_watch_table[0]; 59 db_watchpoint_t db_free_watchpoints = 0; 60 db_watchpoint_t db_watchpoint_list = 0; 61 62 db_watchpoint_t 63 db_watchpoint_alloc() 64 { 65 db_watchpoint_t watch; 66 67 if ((watch = db_free_watchpoints) != 0) { 68 db_free_watchpoints = watch->link; 69 return (watch); 70 } 71 if (db_next_free_watchpoint == &db_watch_table[NWATCHPOINTS]) { 72 db_printf("All watchpoints used.\n"); 73 return (0); 74 } 75 watch = db_next_free_watchpoint; 76 db_next_free_watchpoint++; 77 78 return (watch); 79 } 80 81 void 82 db_watchpoint_free(watch) 83 db_watchpoint_t watch; 84 { 85 watch->link = db_free_watchpoints; 86 db_free_watchpoints = watch; 87 } 88 89 void 90 db_set_watchpoint(map, addr, size) 91 struct vm_map *map; 92 db_addr_t addr; 93 vsize_t size; 94 { 95 db_watchpoint_t watch; 96 97 if (map == NULL) { 98 db_printf("No map.\n"); 99 return; 100 } 101 102 /* 103 * Should we do anything fancy with overlapping regions? 104 */ 105 106 for (watch = db_watchpoint_list; 107 watch != 0; 108 watch = watch->link) 109 if (db_map_equal(watch->map, map) && 110 (watch->loaddr == addr) && 111 (watch->hiaddr == addr+size)) { 112 db_printf("Already set.\n"); 113 return; 114 } 115 116 watch = db_watchpoint_alloc(); 117 if (watch == 0) { 118 db_printf("Too many watchpoints.\n"); 119 return; 120 } 121 122 watch->map = map; 123 watch->loaddr = addr; 124 watch->hiaddr = addr+size; 125 126 watch->link = db_watchpoint_list; 127 db_watchpoint_list = watch; 128 129 db_watchpoints_inserted = FALSE; 130 } 131 132 void 133 db_delete_watchpoint(map, addr) 134 struct vm_map *map; 135 db_addr_t addr; 136 { 137 db_watchpoint_t watch; 138 db_watchpoint_t *prev; 139 140 for (prev = &db_watchpoint_list; 141 (watch = *prev) != 0; 142 prev = &watch->link) 143 if (db_map_equal(watch->map, map) && 144 (watch->loaddr <= addr) && 145 (addr < watch->hiaddr)) { 146 *prev = watch->link; 147 db_watchpoint_free(watch); 148 return; 149 } 150 151 db_printf("Not set.\n"); 152 } 153 154 void 155 db_list_watchpoints() 156 { 157 db_watchpoint_t watch; 158 159 if (db_watchpoint_list == 0) { 160 db_printf("No watchpoints set\n"); 161 return; 162 } 163 164 db_printf(" Map Address Size\n"); 165 for (watch = db_watchpoint_list; 166 watch != 0; 167 watch = watch->link) 168 db_printf("%s%p %8lx %lx\n", 169 db_map_current(watch->map) ? "*" : " ", 170 watch->map, watch->loaddr, 171 watch->hiaddr - watch->loaddr); 172 } 173 174 /* Delete watchpoint */ 175 /*ARGSUSED*/ 176 void 177 db_deletewatch_cmd(addr, have_addr, count, modif) 178 db_expr_t addr; 179 int have_addr; 180 db_expr_t count; 181 char * modif; 182 { 183 db_delete_watchpoint(db_map_addr(addr), addr); 184 } 185 186 /* Set watchpoint */ 187 /*ARGSUSED*/ 188 void 189 db_watchpoint_cmd(addr, have_addr, count, modif) 190 db_expr_t addr; 191 int have_addr; 192 db_expr_t count; 193 char * modif; 194 { 195 vsize_t size; 196 db_expr_t value; 197 198 if (db_expression(&value)) 199 size = (vsize_t) value; 200 else 201 size = 4; 202 db_skip_to_eol(); 203 204 db_set_watchpoint(db_map_addr(addr), addr, size); 205 } 206 207 /* list watchpoints */ 208 /*ARGSUSED*/ 209 void 210 db_listwatch_cmd(addr, have_addr, count, modif) 211 db_expr_t addr; 212 int have_addr; 213 db_expr_t count; 214 char * modif; 215 { 216 db_list_watchpoints(); 217 } 218 219 void 220 db_set_watchpoints() 221 { 222 db_watchpoint_t watch; 223 224 if (!db_watchpoints_inserted) { 225 for (watch = db_watchpoint_list; 226 watch != 0; 227 watch = watch->link) { 228 pmap_protect(watch->map->pmap, 229 trunc_page(watch->loaddr), 230 round_page(watch->hiaddr), 231 VM_PROT_READ); 232 pmap_update(watch->map->pmap); 233 } 234 235 db_watchpoints_inserted = TRUE; 236 } 237 } 238 239 void 240 db_clear_watchpoints() 241 { 242 db_watchpoints_inserted = FALSE; 243 } 244 245 boolean_t 246 db_find_watchpoint(map, addr, regs) 247 struct vm_map *map; 248 db_addr_t addr; 249 db_regs_t *regs; 250 { 251 db_watchpoint_t watch; 252 db_watchpoint_t found = 0; 253 254 for (watch = db_watchpoint_list; 255 watch != 0; 256 watch = watch->link) 257 if (db_map_equal(watch->map, map)) { 258 if ((watch->loaddr <= addr) && 259 (addr < watch->hiaddr)) 260 return (TRUE); 261 else if ((trunc_page(watch->loaddr) <= addr) && 262 (addr < round_page(watch->hiaddr))) 263 found = watch; 264 } 265 266 /* 267 * We didn't hit exactly on a watchpoint, but we are 268 * in a protected region. We want to single-step 269 * and then re-protect. 270 */ 271 272 if (found) { 273 db_watchpoints_inserted = FALSE; 274 db_single_step(regs); 275 } 276 277 return (FALSE); 278 } 279