db_sym.c revision 1.68
1 /* $NetBSD: db_sym.c,v 1.68 2021/12/13 01:25:29 chs 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 (at) 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 1.68 2021/12/13 01:25:29 chs 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 #ifndef _KERNEL 47 #define TBLNAME "netbsd" 48 49 #define use_ksyms 0 50 51 const db_symformat_t *db_symformat; 52 static db_forall_func_t db_sift; 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 ksyms_addsyms_elf(symsize, vss, vse); /* Will complain if necessary */ 67 #else /* _KERNEL */ 68 db_symformat = &db_symformat_elf; 69 if ((*db_symformat->sym_init)(symsize, vss, vse, TBLNAME) != true) 70 printf("sym_init failed"); 71 #endif /* _KERNEL */ 72 } 73 74 bool 75 db_eqname(const char *src, const char *dst, int c) 76 { 77 78 if (!strcmp(src, dst)) 79 return (true); 80 if (src[0] == c) 81 return (!strcmp(src+1,dst)); 82 return (false); 83 } 84 85 bool 86 db_value_of_name(const char *name, db_expr_t *valuep) 87 { 88 char symbol[128]; 89 char *mod, *sym; 90 #ifdef _KERNEL 91 unsigned long uval; 92 long val; 93 #endif 94 95 #ifndef _KERNEL 96 if (!use_ksyms) { 97 db_sym_t ssym; 98 99 /* 100 * Cannot load symtabs in a.out kernels, so the ':' 101 * style of selecting modules is irrelevant. 102 */ 103 ssym = (*db_symformat->sym_lookup)(NULL, name); 104 if (ssym == DB_SYM_NULL) 105 return (false); 106 db_symbol_values(ssym, &name, valuep); 107 return (true); 108 } 109 #endif 110 111 (void)strlcpy(symbol, name, sizeof(symbol)); 112 db_symsplit(symbol, &mod, &sym); 113 #ifdef _KERNEL 114 if (ksyms_getval_unlocked(mod, sym, NULL, &uval, KSYMS_EXTERN) == 0) { 115 val = (long) uval; 116 *valuep = (db_expr_t)val; 117 return true; 118 } 119 if (ksyms_getval_unlocked(mod, sym, NULL, &uval, KSYMS_ANY) == 0) { 120 val = (long) uval; 121 *valuep = (db_expr_t)val; 122 return true; 123 } 124 #endif 125 return false; 126 } 127 128 #ifndef _KERNEL 129 /* Private structure for passing args to db_sift() from db_sifting(). */ 130 struct db_sift_args { 131 char *symstr; 132 int mode; 133 }; 134 135 /* 136 * Does the work of db_sifting(), called once for each 137 * symbol via db_forall(), prints out symbols matching 138 * criteria. 139 */ 140 static void 141 db_sift(db_symtab_t *stab, db_sym_t sym, char *name, 142 char *suffix, int prefix, void *arg) 143 { 144 char c, sc; 145 char *find, *p; 146 size_t len; 147 struct db_sift_args *dsa; 148 149 dsa = (struct db_sift_args*)arg; 150 151 find = dsa->symstr; /* String we're looking for. */ 152 p = name; /* String we're searching within. */ 153 154 /* Matching algorithm cribbed from strstr(), which is not 155 in the kernel. */ 156 if ((c = *find++) != 0) { 157 len = strlen(find); 158 do { 159 do { 160 if ((sc = *p++) == 0) 161 return; 162 } while (sc != c); 163 } while (strncmp(p, find, len) != 0); 164 } 165 if (dsa->mode=='F') /* ala ls -F */ 166 db_printf("%s%s ", name, suffix); 167 else 168 db_printf("%s ", name); 169 } 170 #endif 171 172 /* 173 * "Sift" for a partial symbol. 174 * Named for the Sun OpenPROM command ("sifting"). 175 * If the symbol has a qualifier (e.g., ux:vm_map), 176 * then only the specified symbol table will be searched; 177 * otherwise, all symbol tables will be searched.. 178 * 179 * "mode" is how-to-display, set from modifiers. 180 */ 181 void 182 db_sifting(char *symstr, int mode) 183 { 184 #ifdef _KERNEL 185 char *mod, *sym; 186 #endif 187 188 #ifndef _KERNEL 189 struct db_sift_args dsa; 190 191 if (!use_ksyms) { 192 dsa.symstr = symstr; 193 dsa.mode = mode; 194 (*db_symformat->sym_forall)(NULL, db_sift, &dsa); 195 db_printf("\n"); 196 return; 197 } 198 #endif 199 200 #ifdef _KERNEL 201 db_symsplit(symstr, &mod, &sym); 202 if (ksyms_sift(mod, sym, mode) == ENODEV) 203 db_error("invalid symbol table name"); 204 #endif 205 } 206 207 /* 208 * Find the closest symbol to val, and return its name 209 * and the difference between val and the symbol found. 210 */ 211 db_sym_t 212 db_search_symbol(db_addr_t val, db_strategy_t strategy, db_expr_t *offp) 213 { 214 unsigned int diff; 215 db_sym_t ret = DB_SYM_NULL; 216 #ifdef _KERNEL 217 unsigned long naddr; 218 const char *mod; 219 const char *sym; 220 #endif 221 222 #ifndef _KERNEL 223 if (!use_ksyms) { 224 db_expr_t newdiff; 225 db_sym_t ssym; 226 227 diff = ~0u; 228 newdiff = ~0; 229 ssym = (*db_symformat->sym_search) 230 (NULL, val, strategy, &newdiff); 231 if ((unsigned int) newdiff < diff) { 232 diff = newdiff; 233 ret = ssym; 234 } 235 *offp = diff; 236 return ret; 237 } 238 #endif 239 240 #ifdef _KERNEL 241 if (ksyms_getname(&mod, &sym, (vaddr_t)val, strategy) == 0) { 242 (void)ksyms_getval_unlocked(mod, sym, NULL, &naddr, KSYMS_ANY); 243 diff = val - (db_addr_t)naddr; 244 ret = (db_sym_t)naddr; 245 } else 246 #endif 247 diff = 0; 248 *offp = diff; 249 return ret; 250 } 251 252 /* 253 * Return name and value of a symbol 254 */ 255 void 256 db_symbol_values(db_sym_t sym, const char **namep, db_expr_t *valuep) 257 { 258 #ifdef _KERNEL 259 const char *mod; 260 #endif 261 262 if (sym == DB_SYM_NULL) { 263 *namep = 0; 264 return; 265 } 266 267 #ifndef _KERNEL 268 if (!use_ksyms) { 269 db_expr_t value; 270 271 (*db_symformat->sym_value)(NULL, sym, namep, &value); 272 if (valuep) 273 *valuep = value; 274 return; 275 } 276 #endif 277 278 #ifdef _KERNEL 279 if (ksyms_getname(&mod, namep, (vaddr_t)sym, 280 KSYMS_ANY|KSYMS_EXACT) == 0) { 281 if (valuep) 282 *valuep = sym; 283 } else 284 #endif 285 *namep = NULL; 286 } 287 288 289 /* 290 * Print a the closest symbol to value 291 * 292 * After matching the symbol according to the given strategy 293 * we print it in the name+offset format, provided the symbol's 294 * value is close enough (eg smaller than db_maxoff). 295 * We also attempt to print [filename:linenum] when applicable 296 * (eg for procedure names). 297 * 298 * If we could not find a reasonable name+offset representation, 299 * then we just print the value in hex. Small values might get 300 * bogus symbol associations, e.g. 3 might get some absolute 301 * value like _INCLUDE_VERSION or something, therefore we do 302 * not accept symbols whose value is zero (and use plain hex). 303 */ 304 unsigned int db_maxoff = 0x100000; 305 306 void 307 db_symstr(char *buf, size_t buflen, db_expr_t off, db_strategy_t strategy) 308 { 309 const char *name; 310 #ifdef _KERNEL 311 const char *mod; 312 unsigned long val; 313 #endif 314 315 #ifndef _KERNEL 316 if (!use_ksyms) { 317 db_expr_t d; 318 char *filename; 319 db_expr_t value; 320 int linenum; 321 db_sym_t cursym; 322 323 cursym = db_search_symbol(off, strategy, &d); 324 db_symbol_values(cursym, &name, &value); 325 if (name != NULL && ((unsigned int)d < db_maxoff) && 326 value != 0) { 327 strlcpy(buf, name, buflen); 328 if (d) { 329 strlcat(buf, "+", buflen); 330 db_format_radix(buf + strlen(buf), 24, d, true); 331 } 332 if (strategy == DB_STGY_PROC) { 333 if ((*db_symformat->sym_line_at_pc) 334 (NULL, cursym, &filename, &linenum, off)) { 335 size_t len = strlen(buf); 336 snprintf(buf + len, buflen - len, 337 " [%s:%d]", filename, linenum); 338 } 339 } 340 return; 341 } 342 strlcpy(buf, db_num_to_str(off), buflen); 343 return; 344 } 345 #endif 346 #ifdef _KERNEL 347 if (ksyms_getname(&mod, &name, (vaddr_t)off, 348 strategy|KSYMS_CLOSEST) == 0) { 349 (void)ksyms_getval_unlocked(mod, name, NULL, &val, KSYMS_ANY); 350 if (strategy & KSYMS_PROC && val == off) { 351 if (ksyms_getname(&mod, &name, (vaddr_t)off - 1, 352 strategy|KSYMS_CLOSEST) != 0) 353 goto out; 354 (void)ksyms_getval_unlocked(mod, name, NULL, &val, KSYMS_ANY); 355 } 356 if (((off - val) < db_maxoff) && val) { 357 snprintf(buf, buflen, "%s:%s", mod, name); 358 if (off - val) { 359 strlcat(buf, "+", buflen); 360 db_format_radix(buf+strlen(buf), 361 24, off - val, true); 362 } 363 #ifdef notyet 364 if (strategy & KSYMS_PROC) { 365 if (ksyms_fmaddr(off, &filename, &linenum) == 0) 366 snprintf(buf + strlen(buf), 367 buflen - strlen(buf), 368 " [%s:%d]", filename, linenum); 369 } 370 #endif 371 return; 372 } 373 } 374 out: 375 strlcpy(buf, db_num_to_str(off), buflen); 376 #endif 377 } 378 379 void 380 db_printsym(db_expr_t off, db_strategy_t strategy, 381 void (*pr)(const char *, ...)) 382 { 383 const char *name; 384 #ifdef _KERNEL 385 const char *mod; 386 unsigned long uval; 387 long val; 388 #endif 389 #ifdef notyet 390 char *filename; 391 int linenum; 392 #endif 393 394 #ifndef _KERNEL 395 if (!use_ksyms) { 396 db_expr_t d; 397 char *filename; 398 db_expr_t value; 399 int linenum; 400 db_sym_t cursym; 401 402 cursym = db_search_symbol(off, strategy, &d); 403 db_symbol_values(cursym, &name, &value); 404 if (name != NULL && ((unsigned int)d < db_maxoff) && 405 value != 0) { 406 (*pr)("%s", name); 407 if (d) { 408 char tbuf[24]; 409 410 db_format_radix(tbuf, 24, d, true); 411 (*pr)("+%s", tbuf); 412 } 413 if (strategy == DB_STGY_PROC) { 414 if ((*db_symformat->sym_line_at_pc) 415 (NULL, cursym, &filename, &linenum, off)) 416 (*pr)(" [%s:%d]", filename, linenum); 417 } 418 return; 419 } 420 (*pr)("%s", db_num_to_str(off)); 421 return; 422 } 423 #endif 424 #ifdef _KERNEL 425 if (ksyms_getname(&mod, &name, (vaddr_t)off, 426 strategy|KSYMS_CLOSEST) == 0) { 427 (void)ksyms_getval_unlocked(mod, name, NULL, &uval, KSYMS_ANY); 428 if (strategy & KSYMS_PROC && uval == off) { 429 if (ksyms_getname(&mod, &name, (vaddr_t)off - 1, 430 strategy|KSYMS_CLOSEST) != 0) 431 goto out; 432 (void)ksyms_getval_unlocked(mod, name, NULL, &uval, KSYMS_ANY); 433 } 434 val = (long) uval; 435 if (((off - val) < db_maxoff) && val) { 436 (*pr)("%s:%s", mod, name); 437 if (off - val) { 438 char tbuf[24]; 439 440 db_format_radix(tbuf, 24, off - val, true); 441 (*pr)("+%s", tbuf); 442 } 443 #ifdef notyet 444 if (strategy & KSYMS_PROC) { 445 if (ksyms_fmaddr(off, &filename, &linenum) == 0) 446 (*pr)(" [%s:%d]", filename, linenum); 447 } 448 #endif 449 return; 450 } 451 } 452 #endif 453 out: 454 (*pr)("%s", db_num_to_str(off)); 455 return; 456 } 457 458 /* 459 * Splits a string in the form "mod:sym" to two strings. 460 */ 461 static void 462 db_symsplit(char *str, char **mod, char **sym) 463 { 464 char *cp; 465 466 if ((cp = strchr(str, ':')) != NULL) { 467 *cp++ = '\0'; 468 *mod = str; 469 *sym = cp; 470 } else { 471 *mod = NULL; 472 *sym = str; 473 } 474 } 475 476 bool 477 db_sym_numargs(db_sym_t cursym, int *nargp, char **argnamep) 478 { 479 #ifndef _KERNEL 480 if (!use_ksyms) 481 return ((*db_symformat->sym_numargs)(NULL, cursym, nargp, 482 argnamep)); 483 #endif 484 return (false); 485 } 486 487
Indexes created Tue Sep 23 23:09:58 GMT 2025