db_watch.c revision 22521
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: head/sys/ddb/db_watch.c 22521 1997-02-10 02:22:35Z dyson $ 27 */ 28 29/* 30 * Author: Richard P. Draves, Carnegie Mellon University 31 * Date: 10/90 32 */ 33 34#include <sys/param.h> 35#include <sys/systm.h> 36 37#include <vm/vm.h> 38#include <sys/lock.h> 39#include <vm/pmap.h> 40#include <vm/vm_map.h> 41#include <vm/vm_prot.h> 42 43#include <ddb/ddb.h> 44#include <ddb/db_lex.h> 45#include <ddb/db_watch.h> 46#include <ddb/db_access.h> 47#include <ddb/db_sym.h> 48 49/* 50 * Watchpoints. 51 */ 52 53static boolean_t db_watchpoints_inserted = TRUE; 54 55#define NWATCHPOINTS 100 56static struct db_watchpoint db_watch_table[NWATCHPOINTS]; 57static db_watchpoint_t db_next_free_watchpoint = &db_watch_table[0]; 58static db_watchpoint_t db_free_watchpoints = 0; 59static db_watchpoint_t db_watchpoint_list = 0; 60 61static db_watchpoint_t db_watchpoint_alloc __P((void)); 62static void db_watchpoint_free __P((db_watchpoint_t watch)); 63static void db_delete_watchpoint __P((vm_map_t map, 64 db_addr_t addr)); 65#ifdef notused 66static boolean_t db_find_watchpoint __P((vm_map_t map, db_addr_t addr, 67 db_regs_t *regs)); 68#endif 69static void db_list_watchpoints __P((void)); 70static void db_set_watchpoint __P((vm_map_t map, db_addr_t addr, 71 vm_size_t size)); 72 73 74db_watchpoint_t 75db_watchpoint_alloc() 76{ 77 register db_watchpoint_t watch; 78 79 if ((watch = db_free_watchpoints) != 0) { 80 db_free_watchpoints = watch->link; 81 return (watch); 82 } 83 if (db_next_free_watchpoint == &db_watch_table[NWATCHPOINTS]) { 84 db_printf("All watchpoints used.\n"); 85 return (0); 86 } 87 watch = db_next_free_watchpoint; 88 db_next_free_watchpoint++; 89 90 return (watch); 91} 92 93void 94db_watchpoint_free(watch) 95 register db_watchpoint_t watch; 96{ 97 watch->link = db_free_watchpoints; 98 db_free_watchpoints = watch; 99} 100 101static void 102db_set_watchpoint(map, addr, size) 103 vm_map_t map; 104 db_addr_t addr; 105 vm_size_t size; 106{ 107 register db_watchpoint_t watch; 108 109 if (map == NULL) { 110 db_printf("No map.\n"); 111 return; 112 } 113 114 /* 115 * Should we do anything fancy with overlapping regions? 116 */ 117 118 for (watch = db_watchpoint_list; 119 watch != 0; 120 watch = watch->link) 121 if (db_map_equal(watch->map, map) && 122 (watch->loaddr == addr) && 123 (watch->hiaddr == addr+size)) { 124 db_printf("Already set.\n"); 125 return; 126 } 127 128 watch = db_watchpoint_alloc(); 129 if (watch == 0) { 130 db_printf("Too many watchpoints.\n"); 131 return; 132 } 133 134 watch->map = map; 135 watch->loaddr = addr; 136 watch->hiaddr = addr+size; 137 138 watch->link = db_watchpoint_list; 139 db_watchpoint_list = watch; 140 141 db_watchpoints_inserted = FALSE; 142} 143 144static void 145db_delete_watchpoint(map, addr) 146 vm_map_t map; 147 db_addr_t addr; 148{ 149 register db_watchpoint_t watch; 150 register db_watchpoint_t *prev; 151 152 for (prev = &db_watchpoint_list; 153 (watch = *prev) != 0; 154 prev = &watch->link) 155 if (db_map_equal(watch->map, map) && 156 (watch->loaddr <= addr) && 157 (addr < watch->hiaddr)) { 158 *prev = watch->link; 159 db_watchpoint_free(watch); 160 return; 161 } 162 163 db_printf("Not set.\n"); 164} 165 166static void 167db_list_watchpoints() 168{ 169 register db_watchpoint_t watch; 170 171 if (db_watchpoint_list == 0) { 172 db_printf("No watchpoints set\n"); 173 return; 174 } 175 176 db_printf(" Map Address Size\n"); 177 for (watch = db_watchpoint_list; 178 watch != 0; 179 watch = watch->link) 180 db_printf("%s%8x %8x %x\n", 181 db_map_current(watch->map) ? "*" : " ", 182 watch->map, watch->loaddr, 183 watch->hiaddr - watch->loaddr); 184} 185 186/* Delete watchpoint */ 187/*ARGSUSED*/ 188void 189db_deletewatch_cmd(addr, have_addr, count, modif) 190 db_expr_t addr; 191 boolean_t have_addr; 192 db_expr_t count; 193 char * modif; 194{ 195 db_delete_watchpoint(db_map_addr(addr), addr); 196} 197 198/* Set watchpoint */ 199/*ARGSUSED*/ 200void 201db_watchpoint_cmd(addr, have_addr, count, modif) 202 db_expr_t addr; 203 boolean_t have_addr; 204 db_expr_t count; 205 char * modif; 206{ 207 vm_size_t size; 208 db_expr_t value; 209 210 if (db_expression(&value)) 211 size = (vm_size_t) value; 212 else 213 size = 4; 214 db_skip_to_eol(); 215 216 db_set_watchpoint(db_map_addr(addr), addr, size); 217} 218 219/* list watchpoints */ 220void 221db_listwatch_cmd(dummy1, dummy2, dummy3, dummy4) 222 db_expr_t dummy1; 223 boolean_t dummy2; 224 db_expr_t dummy3; 225 char * dummy4; 226{ 227 db_list_watchpoints(); 228} 229 230void 231db_set_watchpoints() 232{ 233 register 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 248void 249db_clear_watchpoints() 250{ 251 db_watchpoints_inserted = FALSE; 252} 253 254#ifdef notused 255static boolean_t 256db_find_watchpoint(map, addr, regs) 257 vm_map_t map; 258 db_addr_t addr; 259 db_regs_t *regs; 260{ 261 register 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