1 /* $NetBSD: db_variables.c,v 1.45 2017/12/28 17:51:19 christos 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 29 #include <sys/cdefs.h> 30 __KERNEL_RCSID(0, "$NetBSD: db_variables.c,v 1.45 2017/12/28 17:51:19 christos Exp $"); 31 32 #ifdef _KERNEL_OPT 33 #include "opt_ddbparam.h" 34 #endif 35 36 #include <sys/param.h> 37 #include <sys/proc.h> 38 #include <uvm/uvm_extern.h> 39 #include <sys/sysctl.h> 40 41 #include <ddb/ddb.h> 42 #include <ddb/ddbvar.h> 43 44 /* 45 * If this is non-zero, the DDB will be entered when the system 46 * panics. Initialize it so that it's patchable. 47 */ 48 #ifndef DDB_ONPANIC 49 #define DDB_ONPANIC 1 50 #endif 51 int db_onpanic = DDB_ONPANIC; 52 53 /* 54 * Can DDB can be entered from the console? 55 */ 56 #ifndef DDB_FROMCONSOLE 57 #define DDB_FROMCONSOLE 1 58 #endif 59 int db_fromconsole = DDB_FROMCONSOLE; 60 61 /* 62 * Output DDB output to the message buffer? 63 */ 64 #ifndef DDB_TEE_MSGBUF 65 #define DDB_TEE_MSGBUF 0 66 #endif 67 int db_tee_msgbuf = DDB_TEE_MSGBUF; 68 69 #ifndef DDB_PANICSTACKFRAMES 70 #define DDB_PANICSTACKFRAMES 65535 71 #endif 72 int db_panicstackframes = DDB_PANICSTACKFRAMES; 73 74 75 static int db_rw_internal_variable(const struct db_variable *, db_expr_t *, 76 int); 77 static int db_find_variable(const struct db_variable **); 78 79 /* XXX must all be ints for sysctl. */ 80 const struct db_variable db_vars[] = { 81 { 82 .name = "fromconsole", 83 .valuep = &db_fromconsole, 84 .fcn = db_rw_internal_variable, 85 .modif = NULL, 86 }, 87 { 88 .name = "maxoff", 89 .valuep = &db_maxoff, 90 .fcn = db_rw_internal_variable, 91 .modif = NULL, 92 }, 93 { 94 .name = "maxwidth", 95 .valuep = &db_max_width, 96 .fcn = db_rw_internal_variable, 97 .modif = NULL, 98 }, 99 { 100 .name = "lines", 101 .valuep = &db_max_line, 102 .fcn = db_rw_internal_variable, 103 .modif = NULL, 104 }, 105 { 106 .name = "onpanic", 107 .valuep = &db_onpanic, 108 .fcn = db_rw_internal_variable, 109 .modif = NULL, 110 }, 111 { 112 .name = "panicstackframes", 113 .valuep = &db_panicstackframes, 114 .fcn = db_rw_internal_variable, 115 .modif = NULL, 116 }, 117 { 118 .name = "radix", 119 .valuep = &db_radix, 120 .fcn = db_rw_internal_variable, 121 .modif = NULL, 122 }, 123 { 124 .name = "tabstops", 125 .valuep = &db_tab_stop_width, 126 .fcn = db_rw_internal_variable, 127 .modif = NULL, 128 }, 129 { 130 .name = "tee_msgbuf", 131 .valuep = &db_tee_msgbuf, 132 .fcn = db_rw_internal_variable, 133 .modif = NULL, 134 }, 135 }; 136 const struct db_variable * const db_evars = db_vars + __arraycount(db_vars); 137 138 /* 139 * ddb command line access to the DDB variables defined above. 140 */ 141 static int 142 db_rw_internal_variable(const struct db_variable *vp, db_expr_t *valp, int rw) 143 { 144 145 if (rw == DB_VAR_GET) 146 *valp = *(int *)vp->valuep; 147 else 148 *(int *)vp->valuep = *valp; 149 return (0); 150 } 151 152 /* 153 * sysctl(3) access to the DDB variables defined above. 154 */ 155 #ifdef _KERNEL 156 SYSCTL_SETUP(sysctl_ddb_setup, "sysctl ddb subtree setup") 157 { 158 159 sysctl_createv(clog, 0, NULL, NULL, 160 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 161 CTLTYPE_INT, "radix", 162 SYSCTL_DESCR("Input and output radix"), 163 NULL, 0, &db_radix, 0, 164 CTL_DDB, DDBCTL_RADIX, CTL_EOL); 165 sysctl_createv(clog, 0, NULL, NULL, 166 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 167 CTLTYPE_INT, "maxoff", 168 SYSCTL_DESCR("Maximum symbol offset"), 169 NULL, 0, &db_maxoff, 0, 170 CTL_DDB, DDBCTL_MAXOFF, CTL_EOL); 171 sysctl_createv(clog, 0, NULL, NULL, 172 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 173 CTLTYPE_INT, "maxwidth", 174 SYSCTL_DESCR("Maximum output line width"), 175 NULL, 0, &db_max_width, 0, 176 CTL_DDB, DDBCTL_MAXWIDTH, CTL_EOL); 177 sysctl_createv(clog, 0, NULL, NULL, 178 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 179 CTLTYPE_INT, "lines", 180 SYSCTL_DESCR("Number of display lines"), 181 NULL, 0, &db_max_line, 0, 182 CTL_DDB, DDBCTL_LINES, CTL_EOL); 183 sysctl_createv(clog, 0, NULL, NULL, 184 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 185 CTLTYPE_INT, "tabstops", 186 SYSCTL_DESCR("Output tab width"), 187 NULL, 0, &db_tab_stop_width, 0, 188 CTL_DDB, DDBCTL_TABSTOPS, CTL_EOL); 189 sysctl_createv(clog, 0, NULL, NULL, 190 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 191 CTLTYPE_INT, "onpanic", 192 SYSCTL_DESCR("Whether to enter ddb on a kernel panic"), 193 NULL, 0, &db_onpanic, 0, 194 CTL_DDB, DDBCTL_ONPANIC, CTL_EOL); 195 sysctl_createv(clog, 0, NULL, NULL, 196 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 197 CTLTYPE_INT, "fromconsole", 198 SYSCTL_DESCR("Whether ddb can be entered from the " 199 "console"), 200 NULL, 0, &db_fromconsole, 0, 201 CTL_DDB, DDBCTL_FROMCONSOLE, CTL_EOL); 202 sysctl_createv(clog, 0, NULL, NULL, 203 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 204 CTLTYPE_INT, "tee_msgbuf", 205 SYSCTL_DESCR("Whether to tee ddb output to the msgbuf"), 206 NULL, 0, &db_tee_msgbuf, 0, 207 CTL_DDB, CTL_CREATE, CTL_EOL); 208 sysctl_createv(clog, 0, NULL, NULL, 209 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 210 CTLTYPE_STRING, "commandonenter", 211 SYSCTL_DESCR("Command to be executed on each ddb enter"), 212 NULL, 0, db_cmd_on_enter, DB_LINE_MAXLEN, 213 CTL_DDB, CTL_CREATE, CTL_EOL); 214 sysctl_createv(clog, 0, NULL, NULL, 215 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 216 CTLTYPE_INT, "panicstackframes", 217 SYSCTL_DESCR("Number of stack frames to print on panic"), 218 NULL, 0, &db_panicstackframes, 0, 219 CTL_DDB, CTL_CREATE, CTL_EOL); 220 } 221 #endif /* _KERNEL */ 222 223 int 224 db_find_variable(const struct db_variable **varp) 225 { 226 int t; 227 const struct db_variable *vp; 228 229 t = db_read_token(); 230 if (t == tIDENT) { 231 for (vp = db_vars; vp < db_evars; vp++) { 232 if (!strcmp(db_tok_string, vp->name)) { 233 *varp = vp; 234 return (1); 235 } 236 } 237 for (vp = db_regs; vp < db_eregs; vp++) { 238 if (!strcmp(db_tok_string, vp->name)) { 239 *varp = vp; 240 return (1); 241 } 242 } 243 } 244 db_error("Unknown variable\n"); 245 /*NOTREACHED*/ 246 return 0; 247 } 248 249 int 250 db_get_variable(db_expr_t *valuep) 251 { 252 const struct db_variable *vp; 253 254 if (!db_find_variable(&vp)) 255 return (0); 256 257 db_read_variable(vp, valuep); 258 259 return (1); 260 } 261 262 int 263 db_set_variable(db_expr_t value) 264 { 265 const struct db_variable *vp; 266 267 if (!db_find_variable(&vp)) 268 return (0); 269 270 db_write_variable(vp, &value); 271 272 return (1); 273 } 274 275 276 void 277 db_read_variable(const struct db_variable *vp, db_expr_t *valuep) 278 { 279 int (*func)(const struct db_variable *, db_expr_t *, int) = vp->fcn; 280 281 if (func == FCN_NULL) 282 *valuep = *(db_expr_t *)vp->valuep; 283 else 284 (*func)(vp, valuep, DB_VAR_GET); 285 } 286 287 void 288 db_write_variable(const struct db_variable *vp, db_expr_t *valuep) 289 { 290 int (*func)(const struct db_variable *, db_expr_t *, int) = vp->fcn; 291 292 if (func == FCN_NULL) 293 *(db_expr_t *)vp->valuep = *valuep; 294 else 295 (*func)(vp, valuep, DB_VAR_SET); 296 } 297 298 /*ARGSUSED*/ 299 void 300 db_set_cmd(db_expr_t addr, bool have_addr, 301 db_expr_t count, const char *modif) 302 { 303 db_expr_t value; 304 db_expr_t old_value; 305 const struct db_variable *vp = NULL; /* XXX: GCC */ 306 int t; 307 308 t = db_read_token(); 309 if (t != tDOLLAR) { 310 db_error("Unknown variable\n"); 311 /*NOTREACHED*/ 312 } 313 if (!db_find_variable(&vp)) { 314 db_error("Unknown variable\n"); 315 /*NOTREACHED*/ 316 } 317 318 t = db_read_token(); 319 if (t != tEQ) 320 db_unread_token(t); 321 322 if (!db_expression(&value)) { 323 db_error("No value\n"); 324 /*NOTREACHED*/ 325 } 326 if (db_read_token() != tEOL) { 327 db_error("?\n"); 328 /*NOTREACHED*/ 329 } 330 331 db_read_variable(vp, &old_value); 332 db_printf("$%s\t\t%s = ", vp->name, db_num_to_str(old_value)); 333 db_printf("%s\n", db_num_to_str(value)); 334 db_write_variable(vp, &value); 335 } 336