1 /* $NetBSD: db_sym.c,v 1.71 2022/08/30 22:38:01 riastradh 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 1.71 2022/08/30 22:38:01 riastradh 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 #include <sys/pserialize.h> 41 42 #include <ddb/ddb.h> 43 44 static void db_symsplit(char *, char **, char **); 45 46 47 #ifndef _KERNEL 48 #define TBLNAME "netbsd" 49 50 #define use_ksyms 0 51 52 const db_symformat_t *db_symformat; 53 static db_forall_func_t db_sift; 54 extern db_symformat_t db_symformat_elf; 55 #endif 56 57 58 /* 59 * Initialize the kernel debugger by initializing the master symbol 60 * table. Note that if initializing the master symbol table fails, 61 * no other symbol tables can be loaded. 62 */ 63 void 64 ddb_init(int symsize, void *vss, void *vse) 65 { 66 #ifdef _KERNEL 67 ksyms_addsyms_elf(symsize, vss, vse); /* Will complain if necessary */ 68 #else /* _KERNEL */ 69 db_symformat = &db_symformat_elf; 70 if ((*db_symformat->sym_init)(symsize, vss, vse, TBLNAME) != true) 71 printf("sym_init failed"); 72 #endif /* _KERNEL */ 73 } 74 75 bool 76 db_eqname(const char *src, const char *dst, int c) 77 { 78 79 if (!strcmp(src, dst)) 80 return (true); 81 if (src[0] == c) 82 return (!strcmp(src+1,dst)); 83 return (false); 84 } 85 86 bool 87 db_value_of_name(const char *name, db_expr_t *valuep) 88 { 89 char symbol[128]; 90 char *mod, *sym; 91 #ifdef _KERNEL 92 unsigned long uval; 93 long val; 94 #endif 95 96 #ifndef _KERNEL 97 if (!use_ksyms) { 98 db_sym_t ssym; 99 100 /* 101 * Cannot load symtabs in a.out kernels, so the ':' 102 * style of selecting modules is irrelevant. 103 */ 104 ssym = (*db_symformat->sym_lookup)(NULL, name); 105 if (ssym == DB_SYM_NULL) 106 return (false); 107 db_symbol_values(ssym, &name, valuep); 108 return (true); 109 } 110 #endif 111 112 (void)strlcpy(symbol, name, sizeof(symbol)); 113 db_symsplit(symbol, &mod, &sym); 114 #ifdef _KERNEL 115 if (ksyms_getval_unlocked(mod, sym, NULL, &uval, KSYMS_EXTERN) == 0) { 116 val = (long) uval; 117 *valuep = (db_expr_t)val; 118 return true; 119 } 120 if (ksyms_getval_unlocked(mod, sym, NULL, &uval, KSYMS_ANY) == 0) { 121 val = (long) uval; 122 *valuep = (db_expr_t)val; 123 return true; 124 } 125 #endif 126 return false; 127 } 128 129 #ifndef _KERNEL 130 /* Private structure for passing args to db_sift() from db_sifting(). */ 131 struct db_sift_args { 132 char *symstr; 133 int mode; 134 }; 135 136 /* 137 * Does the work of db_sifting(), called once for each 138 * symbol via db_forall(), prints out symbols matching 139 * criteria. 140 */ 141 static void 142 db_sift(db_symtab_t *stab, db_sym_t sym, char *name, 143 char *suffix, int prefix, void *arg) 144 { 145 char c, sc; 146 char *find, *p; 147 size_t len; 148 struct db_sift_args *dsa; 149 150 dsa = (struct db_sift_args*)arg; 151 152 find = dsa->symstr; /* String we're looking for. */ 153 p = name; /* String we're searching within. */ 154 155 /* Matching algorithm cribbed from strstr(), which is not 156 in the kernel. */ 157 if ((c = *find++) != 0) { 158 len = strlen(find); 159 do { 160 do { 161 if ((sc = *p++) == 0) 162 return; 163 } while (sc != c); 164 } while (strncmp(p, find, len) != 0); 165 } 166 if (dsa->mode=='F') /* ala ls -F */ 167 db_printf("%s%s ", name, suffix); 168 else 169 db_printf("%s ", name); 170 } 171 #endif 172 173 /* 174 * "Sift" for a partial symbol. 175 * Named for the Sun OpenPROM command ("sifting"). 176 * If the symbol has a qualifier (e.g., ux:vm_map), 177 * then only the specified symbol table will be searched; 178 * otherwise, all symbol tables will be searched.. 179 * 180 * "mode" is how-to-display, set from modifiers. 181 */ 182 void 183 db_sifting(char *symstr, int mode) 184 { 185 #ifdef _KERNEL 186 char *mod, *sym; 187 #endif 188 189 #ifndef _KERNEL 190 struct db_sift_args dsa; 191 192 if (!use_ksyms) { 193 dsa.symstr = symstr; 194 dsa.mode = mode; 195 (*db_symformat->sym_forall)(NULL, db_sift, &dsa); 196 db_printf("\n"); 197 return; 198 } 199 #endif 200 201 #ifdef _KERNEL 202 db_symsplit(symstr, &mod, &sym); 203 if (ksyms_sift(mod, sym, mode) == ENODEV) 204 db_error("invalid symbol table name"); 205 #endif 206 } 207 208 /* 209 * Find the closest symbol to val, and return its name 210 * and the difference between val and the symbol found. 211 */ 212 db_sym_t 213 db_search_symbol(db_addr_t val, db_strategy_t strategy, db_expr_t *offp) 214 { 215 unsigned int diff; 216 db_sym_t ret = DB_SYM_NULL; 217 #ifdef _KERNEL 218 unsigned long naddr; 219 const char *mod; 220 const char *sym; 221 #endif 222 223 #ifndef _KERNEL 224 if (!use_ksyms) { 225 db_expr_t newdiff; 226 db_sym_t ssym; 227 228 diff = ~0u; 229 newdiff = ~0; 230 ssym = (*db_symformat->sym_search) 231 (NULL, val, strategy, &newdiff); 232 if ((unsigned int) newdiff < diff) { 233 diff = newdiff; 234 ret = ssym; 235 } 236 *offp = diff; 237 return ret; 238 } 239 #endif 240 241 #ifdef _KERNEL 242 if (ksyms_getname(&mod, &sym, (vaddr_t)val, strategy) == 0) { 243 (void)ksyms_getval_unlocked(mod, sym, NULL, &naddr, KSYMS_ANY); 244 diff = val - (db_addr_t)naddr; 245 ret = (db_sym_t)naddr; 246 } else 247 #endif 248 diff = 0; 249 *offp = diff; 250 return ret; 251 } 252 253 /* 254 * Return name and value of a symbol 255 */ 256 void 257 db_symbol_values(db_sym_t sym, const char **namep, db_expr_t *valuep) 258 { 259 #ifdef _KERNEL 260 const char *mod; 261 #endif 262 263 if (sym == DB_SYM_NULL) { 264 *namep = 0; 265 return; 266 } 267 268 #ifndef _KERNEL 269 if (!use_ksyms) { 270 db_expr_t value; 271 272 (*db_symformat->sym_value)(NULL, sym, namep, &value); 273 if (valuep) 274 *valuep = value; 275 return; 276 } 277 #endif 278 279 #ifdef _KERNEL 280 if (ksyms_getname(&mod, namep, (vaddr_t)sym, 281 KSYMS_ANY|KSYMS_EXACT) == 0) { 282 if (valuep) 283 *valuep = sym; 284 } else 285 #endif 286 *namep = NULL; 287 } 288 289 290 /* 291 * Print a the closest symbol to value 292 * 293 * After matching the symbol according to the given strategy 294 * we print it in the name+offset format, provided the symbol's 295 * value is close enough (eg smaller than db_maxoff). 296 * We also attempt to print [filename:linenum] when applicable 297 * (eg for procedure names). 298 * 299 * If we could not find a reasonable name+offset representation, 300 * then we just print the value in hex. Small values might get 301 * bogus symbol associations, e.g. 3 might get some absolute 302 * value like _INCLUDE_VERSION or something, therefore we do 303 * not accept symbols whose value is zero (and use plain hex). 304 */ 305 unsigned int db_maxoff = 0x100000; 306 307 void 308 db_symstr(char *buf, size_t buflen, db_expr_t off, db_strategy_t strategy) 309 { 310 const char *name; 311 #ifdef _KERNEL 312 const char *mod; 313 unsigned long val; 314 #endif 315 316 #ifndef _KERNEL 317 if (!use_ksyms) { 318 db_expr_t d; 319 char *filename; 320 db_expr_t value; 321 int linenum; 322 db_sym_t cursym; 323 324 cursym = db_search_symbol(off, strategy, &d); 325 db_symbol_values(cursym, &name, &value); 326 if (name != NULL && ((unsigned int)d < db_maxoff) && 327 value != 0) { 328 strlcpy(buf, name, buflen); 329 if (d) { 330 strlcat(buf, "+", buflen); 331 db_format_radix(buf + strlen(buf), 24, d, true); 332 } 333 if (strategy == DB_STGY_PROC) { 334 if ((*db_symformat->sym_line_at_pc) 335 (NULL, cursym, &filename, &linenum, off)) { 336 size_t len = strlen(buf); 337 snprintf(buf + len, buflen - len, 338 " [%s:%d]", filename, linenum); 339 } 340 } 341 return; 342 } 343 strlcpy(buf, db_num_to_str(off), buflen); 344 return; 345 } 346 #endif 347 #ifdef _KERNEL 348 const int s = pserialize_read_enter(); 349 if (ksyms_getname(&mod, &name, (vaddr_t)off, 350 strategy|KSYMS_CLOSEST) == 0) { 351 (void)ksyms_getval_unlocked(mod, name, NULL, &val, KSYMS_ANY); 352 if (strategy & KSYMS_PROC && val == off) { 353 if (ksyms_getname(&mod, &name, (vaddr_t)off - 1, 354 strategy|KSYMS_CLOSEST) != 0) 355 goto hex_fallback; 356 (void)ksyms_getval_unlocked(mod, name, NULL, &val, KSYMS_ANY); 357 } 358 if (((off - val) < db_maxoff) && val) { 359 snprintf(buf, buflen, "%s:%s", mod, name); 360 if (off - val) { 361 strlcat(buf, "+", buflen); 362 db_format_radix(buf+strlen(buf), 363 24, off - val, true); 364 } 365 #ifdef notyet 366 if (strategy & KSYMS_PROC) { 367 if (ksyms_fmaddr(off, &filename, &linenum) == 0) 368 snprintf(buf + strlen(buf), 369 buflen - strlen(buf), 370 " [%s:%d]", filename, linenum); 371 } 372 #endif 373 goto out; 374 } 375 } 376 hex_fallback: 377 db_num_to_strbuf(off, buf, buflen); 378 out: pserialize_read_exit(s); 379 #endif 380 } 381 382 void 383 db_printsym(db_expr_t off, db_strategy_t strategy, 384 void (*pr)(const char *, ...)) 385 { 386 const char *name; 387 #ifdef _KERNEL 388 const char *mod; 389 unsigned long uval; 390 long val; 391 #endif 392 #ifdef notyet 393 char *filename; 394 int linenum; 395 #endif 396 397 #ifndef _KERNEL 398 if (!use_ksyms) { 399 db_expr_t d; 400 char *filename; 401 db_expr_t value; 402 int linenum; 403 db_sym_t cursym; 404 405 cursym = db_search_symbol(off, strategy, &d); 406 db_symbol_values(cursym, &name, &value); 407 if (name != NULL && ((unsigned int)d < db_maxoff) && 408 value != 0) { 409 (*pr)("%s", name); 410 if (d) { 411 char tbuf[24]; 412 413 db_format_radix(tbuf, 24, d, true); 414 (*pr)("+%s", tbuf); 415 } 416 if (strategy == DB_STGY_PROC) { 417 if ((*db_symformat->sym_line_at_pc) 418 (NULL, cursym, &filename, &linenum, off)) 419 (*pr)(" [%s:%d]", filename, linenum); 420 } 421 return; 422 } 423 (*pr)("%s", db_num_to_str(off)); 424 return; 425 } 426 #endif 427 #ifdef _KERNEL 428 if (ksyms_getname(&mod, &name, (vaddr_t)off, 429 strategy|KSYMS_CLOSEST) == 0) { 430 (void)ksyms_getval_unlocked(mod, name, NULL, &uval, KSYMS_ANY); 431 if (strategy & KSYMS_PROC && uval == off) { 432 if (ksyms_getname(&mod, &name, (vaddr_t)off - 1, 433 strategy|KSYMS_CLOSEST) != 0) 434 goto out; 435 (void)ksyms_getval_unlocked(mod, name, NULL, &uval, KSYMS_ANY); 436 } 437 val = (long) uval; 438 if (((off - val) < db_maxoff) && val) { 439 (*pr)("%s:%s", mod, name); 440 if (off - val) { 441 char tbuf[24]; 442 443 db_format_radix(tbuf, 24, off - val, true); 444 (*pr)("+%s", tbuf); 445 } 446 #ifdef notyet 447 if (strategy & KSYMS_PROC) { 448 if (ksyms_fmaddr(off, &filename, &linenum) == 0) 449 (*pr)(" [%s:%d]", filename, linenum); 450 } 451 #endif 452 return; 453 } 454 } 455 out:; 456 #endif 457 (*pr)("%s", db_num_to_str(off)); 458 return; 459 } 460 461 /* 462 * Splits a string in the form "mod:sym" to two strings. 463 */ 464 static void 465 db_symsplit(char *str, char **mod, char **sym) 466 { 467 char *cp; 468 469 if ((cp = strchr(str, ':')) != NULL) { 470 *cp++ = '\0'; 471 *mod = str; 472 *sym = cp; 473 } else { 474 *mod = NULL; 475 *sym = str; 476 } 477 } 478 479 bool 480 db_sym_numargs(db_sym_t cursym, int *nargp, char **argnamep) 481 { 482 #ifndef _KERNEL 483 if (!use_ksyms) 484 return ((*db_symformat->sym_numargs)(NULL, cursym, nargp, 485 argnamep)); 486 #endif 487 return (false); 488 } 489 490
Indexes created Sat Sep 20 22:09:52 GMT 2025