1 /*- 2 * SPDX-License-Identifier: MIT-CMU 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 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 * Author: David B. Golub, Carnegie Mellon University 30 * Date: 7/90 31 */ 32 33 #include <sys/cdefs.h> 34 __FBSDID("$FreeBSD$"); 35 36 #include "opt_kstack_pages.h" 37 38 #include <sys/param.h> 39 #include <sys/pcpu.h> 40 #include <sys/smp.h> 41 #include <sys/systm.h> 42 43 #include <net/vnet.h> 44 45 #include <ddb/ddb.h> 46 #include <ddb/db_sym.h> 47 #include <ddb/db_variables.h> 48 49 #include "opt_ddb.h" 50 51 /* 52 * Multiple symbol tables 53 */ 54 #ifndef MAXNOSYMTABS 55 #define MAXNOSYMTABS 3 /* mach, ux, emulator */ 56 #endif 57 58 static db_symtab_t db_symtabs[MAXNOSYMTABS] = {{0,},}; 59 static int db_nsymtab = 0; 60 61 static db_symtab_t *db_last_symtab; /* where last symbol was found */ 62 63 static c_db_sym_t db_lookup( const char *symstr); 64 static char *db_qualify(c_db_sym_t sym, char *symtabname); 65 static bool db_symbol_is_ambiguous(c_db_sym_t sym); 66 static bool db_line_at_pc(c_db_sym_t, char **, int *, db_expr_t); 67 68 static int db_cpu = -1; 69 70 #ifdef VIMAGE 71 static void *db_vnet = NULL; 72 #endif 73 74 /* 75 * Validate the CPU number used to interpret per-CPU variables so we can 76 * avoid later confusion if an invalid CPU is requested. 77 */ 78 int 79 db_var_db_cpu(struct db_variable *vp, db_expr_t *valuep, int op) 80 { 81 82 switch (op) { 83 case DB_VAR_GET: 84 *valuep = db_cpu; 85 return (1); 86 87 case DB_VAR_SET: 88 if (*(int *)valuep < -1 || *(int *)valuep > mp_maxid) { 89 db_printf("Invalid value: %d\n", *(int*)valuep); 90 return (0); 91 } 92 db_cpu = *(int *)valuep; 93 return (1); 94 95 default: 96 db_printf("db_var_db_cpu: unknown operation\n"); 97 return (0); 98 } 99 } 100 101 /* 102 * Read-only variable reporting the current CPU, which is what we use when 103 * db_cpu is set to -1. 104 */ 105 int 106 db_var_curcpu(struct db_variable *vp, db_expr_t *valuep, int op) 107 { 108 109 switch (op) { 110 case DB_VAR_GET: 111 *valuep = curcpu; 112 return (1); 113 114 case DB_VAR_SET: 115 db_printf("Read-only variable.\n"); 116 return (0); 117 118 default: 119 db_printf("db_var_curcpu: unknown operation\n"); 120 return (0); 121 } 122 } 123 124 #ifdef VIMAGE 125 /* 126 * Validate the virtual network pointer used to interpret per-vnet global 127 * variable expansion. Right now we don't do much here, really we should 128 * walk the global vnet list to check it's an OK pointer. 129 */ 130 int 131 db_var_db_vnet(struct db_variable *vp, db_expr_t *valuep, int op) 132 { 133 134 switch (op) { 135 case DB_VAR_GET: 136 *valuep = (db_expr_t)db_vnet; 137 return (1); 138 139 case DB_VAR_SET: 140 db_vnet = *(void **)valuep; 141 return (1); 142 143 default: 144 db_printf("db_var_db_vnet: unknown operation\n"); 145 return (0); 146 } 147 } 148 149 /* 150 * Read-only variable reporting the current vnet, which is what we use when 151 * db_vnet is set to NULL. 152 */ 153 int 154 db_var_curvnet(struct db_variable *vp, db_expr_t *valuep, int op) 155 { 156 157 switch (op) { 158 case DB_VAR_GET: 159 *valuep = (db_expr_t)curvnet; 160 return (1); 161 162 case DB_VAR_SET: 163 db_printf("Read-only variable.\n"); 164 return (0); 165 166 default: 167 db_printf("db_var_curvnet: unknown operation\n"); 168 return (0); 169 } 170 } 171 #endif 172 173 /* 174 * Add symbol table, with given name, to list of symbol tables. 175 */ 176 void 177 db_add_symbol_table(char *start, char *end, char *name, char *ref) 178 { 179 if (db_nsymtab >= MAXNOSYMTABS) { 180 printf ("No slots left for %s symbol table", name); 181 panic ("db_sym.c: db_add_symbol_table"); 182 } 183 184 db_symtabs[db_nsymtab].start = start; 185 db_symtabs[db_nsymtab].end = end; 186 db_symtabs[db_nsymtab].name = name; 187 db_symtabs[db_nsymtab].private = ref; 188 db_nsymtab++; 189 } 190 191 /* 192 * db_qualify("vm_map", "ux") returns "unix:vm_map". 193 * 194 * Note: return value points to static data whose content is 195 * overwritten by each call... but in practice this seems okay. 196 */ 197 static char * 198 db_qualify(c_db_sym_t sym, char *symtabname) 199 { 200 const char *symname; 201 static char tmp[256]; 202 203 db_symbol_values(sym, &symname, 0); 204 snprintf(tmp, sizeof(tmp), "%s:%s", symtabname, symname); 205 return tmp; 206 } 207 208 209 bool 210 db_eqname(const char *src, const char *dst, int c) 211 { 212 if (!strcmp(src, dst)) 213 return (true); 214 if (src[0] == c) 215 return (!strcmp(src+1,dst)); 216 return (false); 217 } 218 219 bool 220 db_value_of_name(const char *name, db_expr_t *valuep) 221 { 222 c_db_sym_t sym; 223 224 sym = db_lookup(name); 225 if (sym == C_DB_SYM_NULL) 226 return (false); 227 db_symbol_values(sym, &name, valuep); 228 return (true); 229 } 230 231 bool 232 db_value_of_name_pcpu(const char *name, db_expr_t *valuep) 233 { 234 static char tmp[256]; 235 db_expr_t value; 236 c_db_sym_t sym; 237 int cpu; 238 239 if (db_cpu != -1) 240 cpu = db_cpu; 241 else 242 cpu = curcpu; 243 snprintf(tmp, sizeof(tmp), "pcpu_entry_%s", name); 244 sym = db_lookup(tmp); 245 if (sym == C_DB_SYM_NULL) 246 return (false); 247 db_symbol_values(sym, &name, &value); 248 if (value < DPCPU_START || value >= DPCPU_STOP) 249 return (false); 250 *valuep = (db_expr_t)((uintptr_t)value + dpcpu_off[cpu]); 251 return (true); 252 } 253 254 bool 255 db_value_of_name_vnet(const char *name, db_expr_t *valuep) 256 { 257 #ifdef VIMAGE 258 static char tmp[256]; 259 db_expr_t value; 260 c_db_sym_t sym; 261 struct vnet *vnet; 262 263 if (db_vnet != NULL) 264 vnet = db_vnet; 265 else 266 vnet = curvnet; 267 snprintf(tmp, sizeof(tmp), "vnet_entry_%s", name); 268 sym = db_lookup(tmp); 269 if (sym == C_DB_SYM_NULL) 270 return (false); 271 db_symbol_values(sym, &name, &value); 272 if (value < VNET_START || value >= VNET_STOP) 273 return (false); 274 *valuep = (db_expr_t)((uintptr_t)value + vnet->vnet_data_base); 275 return (true); 276 #else 277 return (false); 278 #endif 279 } 280 281 /* 282 * Lookup a symbol. 283 * If the symbol has a qualifier (e.g., ux:vm_map), 284 * then only the specified symbol table will be searched; 285 * otherwise, all symbol tables will be searched. 286 */ 287 static c_db_sym_t 288 db_lookup(const char *symstr) 289 { 290 c_db_sym_t sp; 291 int i; 292 int symtab_start = 0; 293 int symtab_end = db_nsymtab; 294 const char *cp; 295 296 /* 297 * Look for, remove, and remember any symbol table specifier. 298 */ 299 for (cp = symstr; *cp; cp++) { 300 if (*cp == ':') { 301 for (i = 0; i < db_nsymtab; i++) { 302 int n = strlen(db_symtabs[i].name); 303 304 if ( 305 n == (cp - symstr) && 306 strncmp(symstr, db_symtabs[i].name, n) == 0 307 ) { 308 symtab_start = i; 309 symtab_end = i + 1; 310 break; 311 } 312 } 313 if (i == db_nsymtab) { 314 db_error("invalid symbol table name"); 315 } 316 symstr = cp+1; 317 } 318 } 319 320 /* 321 * Look in the specified set of symbol tables. 322 * Return on first match. 323 */ 324 for (i = symtab_start; i < symtab_end; i++) { 325 sp = X_db_lookup(&db_symtabs[i], symstr); 326 if (sp) { 327 db_last_symtab = &db_symtabs[i]; 328 return sp; 329 } 330 } 331 return 0; 332 } 333 334 /* 335 * If true, check across symbol tables for multiple occurrences 336 * of a name. Might slow things down quite a bit. 337 */ 338 static volatile bool db_qualify_ambiguous_names = false; 339 340 /* 341 * Does this symbol name appear in more than one symbol table? 342 * Used by db_symbol_values to decide whether to qualify a symbol. 343 */ 344 static bool 345 db_symbol_is_ambiguous(c_db_sym_t sym) 346 { 347 const char *sym_name; 348 int i; 349 bool found_once = false; 350 351 if (!db_qualify_ambiguous_names) 352 return (false); 353 354 db_symbol_values(sym, &sym_name, 0); 355 for (i = 0; i < db_nsymtab; i++) { 356 if (X_db_lookup(&db_symtabs[i], sym_name)) { 357 if (found_once) 358 return (true); 359 found_once = true; 360 } 361 } 362 return (false); 363 } 364 365 /* 366 * Find the closest symbol to val, and return its name 367 * and the difference between val and the symbol found. 368 */ 369 c_db_sym_t 370 db_search_symbol(db_addr_t val, db_strategy_t strategy, db_expr_t *offp) 371 { 372 unsigned int diff; 373 size_t newdiff; 374 int i; 375 c_db_sym_t ret = C_DB_SYM_NULL, sym; 376 377 newdiff = diff = val; 378 for (i = 0; i < db_nsymtab; i++) { 379 sym = X_db_search_symbol(&db_symtabs[i], val, strategy, &newdiff); 380 if ((uintmax_t)newdiff < (uintmax_t)diff) { 381 db_last_symtab = &db_symtabs[i]; 382 diff = newdiff; 383 ret = sym; 384 } 385 } 386 *offp = diff; 387 return ret; 388 } 389 390 /* 391 * Return name and value of a symbol 392 */ 393 void 394 db_symbol_values(c_db_sym_t sym, const char **namep, db_expr_t *valuep) 395 { 396 db_expr_t value; 397 398 if (sym == DB_SYM_NULL) { 399 *namep = NULL; 400 return; 401 } 402 403 X_db_symbol_values(db_last_symtab, sym, namep, &value); 404 405 if (db_symbol_is_ambiguous(sym)) 406 *namep = db_qualify(sym, db_last_symtab->name); 407 if (valuep) 408 *valuep = value; 409 } 410 411 412 /* 413 * Print a the closest symbol to value 414 * 415 * After matching the symbol according to the given strategy 416 * we print it in the name+offset format, provided the symbol's 417 * value is close enough (eg smaller than db_maxoff). 418 * We also attempt to print [filename:linenum] when applicable 419 * (eg for procedure names). 420 * 421 * If we could not find a reasonable name+offset representation, 422 * then we just print the value in hex. Small values might get 423 * bogus symbol associations, e.g. 3 might get some absolute 424 * value like _INCLUDE_VERSION or something, therefore we do 425 * not accept symbols whose value is "small" (and use plain hex). 426 */ 427 428 db_expr_t db_maxoff = 0x10000; 429 430 void 431 db_printsym(db_expr_t off, db_strategy_t strategy) 432 { 433 db_expr_t d; 434 char *filename; 435 const char *name; 436 int linenum; 437 c_db_sym_t cursym; 438 439 if (off < 0 && off >= -db_maxoff) { 440 db_printf("%+#lr", (long)off); 441 return; 442 } 443 cursym = db_search_symbol(off, strategy, &d); 444 db_symbol_values(cursym, &name, NULL); 445 if (name == NULL || d >= (db_addr_t)db_maxoff) { 446 db_printf("%#lr", (unsigned long)off); 447 return; 448 } 449 #ifdef DDB_NUMSYM 450 db_printf("%#lr = %s", (unsigned long)off, name); 451 #else 452 db_printf("%s", name); 453 #endif 454 if (d) 455 db_printf("+%+#lr", (long)d); 456 if (strategy == DB_STGY_PROC) { 457 if (db_line_at_pc(cursym, &filename, &linenum, off)) 458 db_printf(" [%s:%d]", filename, linenum); 459 } 460 } 461 462 static bool 463 db_line_at_pc(c_db_sym_t sym, char **filename, int *linenum, db_expr_t pc) 464 { 465 return (X_db_line_at_pc(db_last_symtab, sym, filename, linenum, pc)); 466 } 467 468 bool 469 db_sym_numargs(c_db_sym_t sym, int *nargp, char **argnames) 470 { 471 return (X_db_sym_numargs(db_last_symtab, sym, nargp, argnames)); 472 } 473