1 /* $NetBSD: db_sym.c,v 1.59 2009/03/07 22:02:17 ad 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_sym.c,v 1.59 2009/03/07 22:02:17 ad 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 <sys/systm.h> 39 #include <sys/ksyms.h> 40 41 #include <ddb/ddb.h> 42 43 static void db_symsplit(char *, char **, char **); 44 45 46 #ifdef DB_AOUT_SYMBOLS 47 #define TBLNAME "netbsd" 48 49 static int using_aout_symtab; 50 const db_symformat_t *db_symformat; 51 static db_forall_func_t db_sift; 52 extern db_symformat_t db_symformat_aout; 53 extern db_symformat_t db_symformat_elf; 54 #endif 55 56 57 /* 58 * Initialize the kernel debugger by initializing the master symbol 59 * table. Note that if initializing the master symbol table fails, 60 * no other symbol tables can be loaded. 61 */ 62 void 63 ddb_init(int symsize, void *vss, void *vse) 64 { 65 #ifdef _KERNEL 66 # ifdef DB_AOUT_SYMBOLS 67 db_symformat = &db_symformat_aout; 68 if ((*db_symformat->sym_init)(symsize, vss, vse, TBLNAME) == true) { 69 using_aout_symtab = true; 70 return; 71 } 72 # endif 73 ksyms_addsyms_elf(symsize, vss, vse); /* Will complain if necessary */ 74 #else /* _KERNEL */ 75 db_symformat = &db_symformat_elf; 76 if ((*db_symformat->sym_init)(symsize, vss, vse, TBLNAME) == true) { 77 using_aout_symtab = true; 78 return; 79 } 80 #endif /* _KERNEL */ 81 } 82 83 bool 84 db_eqname(const char *src, const char *dst, int c) 85 { 86 87 if (!strcmp(src, dst)) 88 return (true); 89 if (src[0] == c) 90 return (!strcmp(src+1,dst)); 91 return (false); 92 } 93 94 bool 95 db_value_of_name(const char *name, db_expr_t *valuep) 96 { 97 char symbol[128]; 98 char *mod, *sym; 99 #ifdef _KERNEL 100 unsigned long uval; 101 long val; 102 #endif 103 104 #ifdef DB_AOUT_SYMBOLS 105 db_sym_t ssym; 106 107 if (using_aout_symtab) { 108 /* 109 * Cannot load symtabs in a.out kernels, so the ':' 110 * style of selecting modules is irrelevant. 111 */ 112 ssym = (*db_symformat->sym_lookup)(NULL, name); 113 if (ssym == DB_SYM_NULL) 114 return (false); 115 db_symbol_values(ssym, &name, valuep); 116 return (true); 117 } 118 #endif 119 (void)strlcpy(symbol, name, sizeof(symbol)); 120 db_symsplit(symbol, &mod, &sym); 121 #ifdef _KERNEL 122 if (ksyms_getval_unlocked(mod, sym, &uval, KSYMS_EXTERN) == 0) { 123 val = (long) uval; 124 *valuep = (db_expr_t)val; 125 return true; 126 } 127 if (ksyms_getval_unlocked(mod, sym, &uval, KSYMS_ANY) == 0) { 128 val = (long) uval; 129 *valuep = (db_expr_t)val; 130 return true; 131 } 132 #endif 133 return false; 134 } 135 136 #ifdef DB_AOUT_SYMBOLS 137 /* Private structure for passing args to db_sift() from db_sifting(). */ 138 struct db_sift_args { 139 char *symstr; 140 int mode; 141 }; 142 143 /* 144 * Does the work of db_sifting(), called once for each 145 * symbol via db_forall(), prints out symbols matching 146 * criteria. 147 */ 148 static void 149 db_sift(db_symtab_t *stab, db_sym_t sym, char *name, 150 char *suffix, int prefix, void *arg) 151 { 152 char c, sc; 153 char *find, *p; 154 size_t len; 155 struct db_sift_args *dsa; 156 157 dsa = (struct db_sift_args*)arg; 158 159 find = dsa->symstr; /* String we're looking for. */ 160 p = name; /* String we're searching within. */ 161 162 /* Matching algorithm cribbed from strstr(), which is not 163 in the kernel. */ 164 if ((c = *find++) != 0) { 165 len = strlen(find); 166 do { 167 do { 168 if ((sc = *p++) == 0) 169 return; 170 } while (sc != c); 171 } while (strncmp(p, find, len) != 0); 172 } 173 if (dsa->mode=='F') /* ala ls -F */ 174 db_printf("%s%s ", name, suffix); 175 else 176 db_printf("%s ", name); 177 } 178 #endif 179 180 /* 181 * "Sift" for a partial symbol. 182 * Named for the Sun OpenPROM command ("sifting"). 183 * If the symbol has a qualifier (e.g., ux:vm_map), 184 * then only the specified symbol table will be searched; 185 * otherwise, all symbol tables will be searched.. 186 * 187 * "mode" is how-to-display, set from modifiers. 188 */ 189 void 190 db_sifting(char *symstr, int mode) 191 { 192 #ifdef _KERNEL 193 char *mod, *sym; 194 #endif 195 196 #ifdef DB_AOUT_SYMBOLS 197 struct db_sift_args dsa; 198 199 if (using_aout_symtab) { 200 dsa.symstr = symstr; 201 dsa.mode = mode; 202 (*db_symformat->sym_forall)(NULL, db_sift, &dsa); 203 db_printf("\n"); 204 return; 205 } 206 #endif 207 208 #ifdef _KERNEL 209 db_symsplit(symstr, &mod, &sym); 210 if (ksyms_sift(mod, sym, mode) == ENODEV) 211 db_error("invalid symbol table name"); 212 #endif 213 } 214 215 /* 216 * Find the closest symbol to val, and return its name 217 * and the difference between val and the symbol found. 218 */ 219 db_sym_t 220 db_search_symbol(db_addr_t val, db_strategy_t strategy, db_expr_t *offp) 221 { 222 unsigned int diff; 223 db_sym_t ret = DB_SYM_NULL; 224 #ifdef _KERNEL 225 unsigned long naddr; 226 const char *mod; 227 const char *sym; 228 #endif 229 230 #ifdef DB_AOUT_SYMBOLS 231 db_expr_t newdiff; 232 db_sym_t ssym; 233 234 if (using_aout_symtab) { 235 newdiff = diff = ~0; 236 ssym = (*db_symformat->sym_search) 237 (NULL, val, strategy, &newdiff); 238 if ((unsigned int) newdiff < diff) { 239 diff = newdiff; 240 ret = ssym; 241 } 242 *offp = diff; 243 return ret; 244 } 245 #endif 246 247 #ifdef _KERNEL 248 if (ksyms_getname(&mod, &sym, (vaddr_t)val, strategy) == 0) { 249 (void)ksyms_getval_unlocked(mod, sym, &naddr, KSYMS_ANY); 250 diff = val - (db_addr_t)naddr; 251 ret = (db_sym_t)naddr; 252 } else 253 #endif 254 diff = 0; 255 *offp = diff; 256 return ret; 257 } 258 259 /* 260 * Return name and value of a symbol 261 */ 262 void 263 db_symbol_values(db_sym_t sym, const char **namep, db_expr_t *valuep) 264 { 265 #ifdef _KERNEL 266 const char *mod; 267 #endif 268 269 if (sym == DB_SYM_NULL) { 270 *namep = 0; 271 return; 272 } 273 274 #ifdef DB_AOUT_SYMBOLS 275 if (using_aout_symtab) { 276 db_expr_t value; 277 (*db_symformat->sym_value)(NULL, sym, namep, &value); 278 if (valuep) 279 *valuep = value; 280 return; 281 } 282 #endif 283 284 #ifdef _KERNEL 285 if (ksyms_getname(&mod, namep, (vaddr_t)sym, 286 KSYMS_ANY|KSYMS_EXACT) == 0) { 287 if (valuep) 288 *valuep = sym; 289 } else 290 #endif 291 *namep = NULL; 292 } 293 294 295 /* 296 * Print a the closest symbol to value 297 * 298 * After matching the symbol according to the given strategy 299 * we print it in the name+offset format, provided the symbol's 300 * value is close enough (eg smaller than db_maxoff). 301 * We also attempt to print [filename:linenum] when applicable 302 * (eg for procedure names). 303 * 304 * If we could not find a reasonable name+offset representation, 305 * then we just print the value in hex. Small values might get 306 * bogus symbol associations, e.g. 3 might get some absolute 307 * value like _INCLUDE_VERSION or something, therefore we do 308 * not accept symbols whose value is zero (and use plain hex). 309 * Also, avoid printing as "end+0x????" which is useless. 310 * The variable db_lastsym is used instead of "end" in case we 311 * add support for symbols in loadable driver modules. 312 */ 313 extern char end[]; 314 unsigned long db_lastsym = (unsigned long)end; 315 unsigned int db_maxoff = 0x100000; 316 317 void 318 db_symstr(char *buf, size_t buflen, db_expr_t off, db_strategy_t strategy) 319 { 320 const char *name; 321 #ifdef _KERNEL 322 const char *mod; 323 unsigned long val; 324 #endif 325 326 #ifdef DB_AOUT_SYMBOLS 327 if (using_aout_symtab) { 328 db_expr_t d; 329 char *filename; 330 db_expr_t value; 331 int linenum; 332 db_sym_t cursym; 333 334 if ((unsigned long) off <= db_lastsym) { 335 cursym = db_search_symbol(off, strategy, &d); 336 db_symbol_values(cursym, &name, &value); 337 if (name != NULL && 338 ((unsigned int) d < db_maxoff) && 339 value != 0) { 340 strlcpy(buf, name, buflen); 341 if (d) { 342 strlcat(buf, "+", buflen); 343 db_format_radix(buf+strlen(buf), 344 24, d, true); 345 } 346 if (strategy == DB_STGY_PROC) { 347 if ((*db_symformat->sym_line_at_pc) 348 (NULL, cursym, &filename, 349 &linenum, off)) 350 snprintf(buf + strlen(buf), 351 buflen - strlen(buf), 352 " [%s:%d]", 353 filename, linenum); 354 } 355 return; 356 } 357 } 358 strlcpy(buf, db_num_to_str(off), buflen); 359 return; 360 } 361 #endif 362 #ifdef _KERNEL 363 if (ksyms_getname(&mod, &name, (vaddr_t)off, 364 strategy|KSYMS_CLOSEST) == 0) { 365 (void)ksyms_getval_unlocked(mod, name, &val, KSYMS_ANY); 366 if (((off - val) < db_maxoff) && val) { 367 snprintf(buf, buflen, "%s:%s", mod, name); 368 if (off - val) { 369 strlcat(buf, "+", buflen); 370 db_format_radix(buf+strlen(buf), 371 24, off - val, true); 372 } 373 #ifdef notyet 374 if (strategy & KSYMS_PROC) { 375 if (ksyms_fmaddr(off, &filename, &linenum) == 0) 376 snprintf(buf + strlen(buf), 377 buflen - strlen(buf), 378 " [%s:%d]", filename, linenum); 379 } 380 #endif 381 return; 382 } 383 } 384 strlcpy(buf, db_num_to_str(off), buflen); 385 #endif 386 } 387 388 void 389 db_printsym(db_expr_t off, db_strategy_t strategy, 390 void (*pr)(const char *, ...)) 391 { 392 const char *name; 393 #ifdef _KERNEL 394 const char *mod; 395 unsigned long uval; 396 long val; 397 #endif 398 #ifdef notyet 399 char *filename; 400 int linenum; 401 #endif 402 403 #ifdef DB_AOUT_SYMBOLS 404 if (using_aout_symtab) { 405 db_expr_t d; 406 char *filename; 407 db_expr_t value; 408 int linenum; 409 db_sym_t cursym; 410 if ((unsigned long) off <= db_lastsym) { 411 cursym = db_search_symbol(off, strategy, &d); 412 db_symbol_values(cursym, &name, &value); 413 if (name != NULL && 414 ((unsigned int) d < db_maxoff) && 415 value != 0) { 416 (*pr)("%s", name); 417 if (d) { 418 char tbuf[24]; 419 420 db_format_radix(tbuf, 24, d, true); 421 (*pr)("+%s", tbuf); 422 } 423 if (strategy == DB_STGY_PROC) { 424 if ((*db_symformat->sym_line_at_pc) 425 (NULL, cursym, &filename, 426 &linenum, off)) 427 (*pr)(" [%s:%d]", 428 filename, linenum); 429 } 430 return; 431 } 432 } 433 (*pr)(db_num_to_str(off)); 434 return; 435 } 436 #endif 437 #ifdef _KERNEL 438 if (ksyms_getname(&mod, &name, (vaddr_t)off, 439 strategy|KSYMS_CLOSEST) == 0) { 440 (void)ksyms_getval_unlocked(mod, name, &uval, KSYMS_ANY); 441 val = (long) uval; 442 if (((off - val) < db_maxoff) && val) { 443 (*pr)("%s:%s", mod, name); 444 if (off - val) { 445 char tbuf[24]; 446 447 db_format_radix(tbuf, 24, off - val, true); 448 (*pr)("+%s", tbuf); 449 } 450 #ifdef notyet 451 if (strategy & KSYMS_PROC) { 452 if (ksyms_fmaddr(off, &filename, &linenum) == 0) 453 (*pr)(" [%s:%d]", filename, linenum); 454 } 455 #endif 456 return; 457 } 458 } 459 #endif 460 (*pr)(db_num_to_str(off)); 461 return; 462 } 463 464 /* 465 * Splits a string in the form "mod:sym" to two strings. 466 */ 467 static void 468 db_symsplit(char *str, char **mod, char **sym) 469 { 470 char *cp; 471 472 if ((cp = strchr(str, ':')) != NULL) { 473 *cp++ = '\0'; 474 *mod = str; 475 *sym = cp; 476 } else { 477 *mod = NULL; 478 *sym = str; 479 } 480 } 481 482 bool 483 db_sym_numargs(db_sym_t cursym, int *nargp, char **argnamep) 484 { 485 #ifdef DB_AOUT_SYMBOLS 486 if (using_aout_symtab) 487 return ((*db_symformat->sym_numargs)(NULL, cursym, nargp, 488 argnamep)); 489 #endif 490 return (false); 491 } 492 493