1 /* $OpenBSD: db_watch.c,v 1.11 2014/07/08 13:02:57 deraadt Exp $ */ 2 /* $NetBSD: db_watch.c,v 1.9 1996/03/30 22:30:12 christos Exp $ */ 3 4 /* 5 * Mach Operating System 6 * Copyright (c) 1993,1992,1991,1990 Carnegie Mellon University 7 * All Rights Reserved. 8 * 9 * Permission to use, copy, modify and distribute this software and its 10 * documentation is hereby granted, provided that both the copyright 11 * notice and this permission notice appear in all copies of the 12 * software, derivative works or modified versions, and any portions 13 * thereof, and that both notices appear in supporting documentation. 14 * 15 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 16 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR 17 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 18 * 19 * Carnegie Mellon requests users of this software to return to 20 * 21 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 22 * School of Computer Science 23 * Carnegie Mellon University 24 * Pittsburgh PA 15213-3890 25 * 26 * any improvements or extensions that they make and grant Carnegie Mellon 27 * the rights to redistribute these changes. 28 * 29 * Author: Richard P. Draves, Carnegie Mellon University 30 * Date: 10/90 31 */ 32 33 #include <sys/param.h> 34 #include <sys/systm.h> 35 #include <sys/proc.h> 36 37 #include <machine/db_machdep.h> 38 39 #include <ddb/db_break.h> 40 #include <ddb/db_watch.h> 41 #include <ddb/db_lex.h> 42 #include <ddb/db_access.h> 43 #include <ddb/db_run.h> 44 #include <ddb/db_sym.h> 45 #include <ddb/db_output.h> 46 #include <ddb/db_command.h> 47 #include <ddb/db_extern.h> 48 49 /* 50 * Watchpoints. 51 */ 52 53 boolean_t db_watchpoints_inserted = TRUE; 54 55 #define NWATCHPOINTS 100 56 struct db_watchpoint db_watch_table[NWATCHPOINTS]; 57 db_watchpoint_t db_next_free_watchpoint = &db_watch_table[0]; 58 db_watchpoint_t db_free_watchpoints = 0; 59 db_watchpoint_t db_watchpoint_list = 0; 60 61 db_watchpoint_t 62 db_watchpoint_alloc(void) 63 { 64 db_watchpoint_t watch; 65 66 if ((watch = db_free_watchpoints) != 0) { 67 db_free_watchpoints = watch->link; 68 return (watch); 69 } 70 if (db_next_free_watchpoint == &db_watch_table[NWATCHPOINTS]) { 71 db_printf("All watchpoints used.\n"); 72 return (0); 73 } 74 watch = db_next_free_watchpoint; 75 db_next_free_watchpoint++; 76 77 return (watch); 78 } 79 80 void 81 db_watchpoint_free(db_watchpoint_t watch) 82 { 83 watch->link = db_free_watchpoints; 84 db_free_watchpoints = watch; 85 } 86 87 void 88 db_set_watchpoint(db_addr_t addr, vsize_t size) 89 { 90 db_watchpoint_t watch; 91 92 /* 93 * Should we do anything fancy with overlapping regions? 94 */ 95 96 for (watch = db_watchpoint_list; watch != 0; watch = watch->link) 97 if (watch->loaddr == addr && watch->hiaddr == addr + size) { 98 db_printf("Already set.\n"); 99 return; 100 } 101 102 watch = db_watchpoint_alloc(); 103 if (watch == 0) { 104 db_printf("Too many watchpoints.\n"); 105 return; 106 } 107 108 watch->loaddr = addr; 109 watch->hiaddr = addr+size; 110 111 watch->link = db_watchpoint_list; 112 db_watchpoint_list = watch; 113 114 db_watchpoints_inserted = FALSE; 115 } 116 117 void 118 db_delete_watchpoint(db_addr_t addr) 119 { 120 db_watchpoint_t watch; 121 db_watchpoint_t *prev; 122 123 for (prev = &db_watchpoint_list; (watch = *prev) != 0; 124 prev = &watch->link) 125 if (watch->loaddr <= addr && addr < watch->hiaddr) { 126 *prev = watch->link; 127 db_watchpoint_free(watch); 128 return; 129 } 130 131 db_printf("Not set.\n"); 132 } 133 134 void 135 db_list_watchpoints(void) 136 { 137 db_watchpoint_t watch; 138 139 if (db_watchpoint_list == 0) { 140 db_printf("No watchpoints set\n"); 141 return; 142 } 143 144 db_printf(" Address Size\n"); 145 for (watch = db_watchpoint_list; watch != 0; watch = watch->link) 146 db_printf("%8lx %lx\n", 147 watch->loaddr, watch->hiaddr - watch->loaddr); 148 } 149 150 /* Delete watchpoint */ 151 /*ARGSUSED*/ 152 void 153 db_deletewatch_cmd(db_expr_t addr, int have_addr, db_expr_t count, char *modif) 154 { 155 db_delete_watchpoint(addr); 156 } 157 158 /* Set watchpoint */ 159 /*ARGSUSED*/ 160 void 161 db_watchpoint_cmd(db_expr_t addr, int have_addr, db_expr_t count, char *modif) 162 { 163 vsize_t size; 164 db_expr_t value; 165 166 if (db_expression(&value)) 167 size = (vsize_t) value; 168 else 169 size = 4; 170 db_skip_to_eol(); 171 172 db_set_watchpoint(addr, size); 173 } 174 175 /* list watchpoints */ 176 /*ARGSUSED*/ 177 void 178 db_listwatch_cmd(db_expr_t addr, int have_addr, db_expr_t count, char *modif) 179 { 180 db_list_watchpoints(); 181 } 182 183 void 184 db_set_watchpoints(void) 185 { 186 db_watchpoint_t watch; 187 188 if (!db_watchpoints_inserted && db_watchpoint_list != NULL) { 189 for (watch = db_watchpoint_list; watch != 0; 190 watch = watch->link) 191 pmap_protect(pmap_kernel(), trunc_page(watch->loaddr), 192 round_page(watch->hiaddr), VM_PROT_READ); 193 pmap_update(pmap_kernel()); 194 db_watchpoints_inserted = TRUE; 195 } 196 } 197 198 void 199 db_clear_watchpoints(void) 200 { 201 db_watchpoints_inserted = FALSE; 202 } 203