1 /* 2 * Mach Operating System 3 * Copyright (c) 1991,1990 Carnegie Mellon University 4 * All Rights Reserved. 5 * 6 * Permission to use, copy, modify and distribute this software and its 7 * documentation is hereby granted, provided that both the copyright 8 * notice and this permission notice appear in all copies of the 9 * software, derivative works or modified versions, and any portions 10 * thereof, and that both notices appear in supporting documentation. 11 * 12 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS 13 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR 14 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 15 * 16 * Carnegie Mellon requests users of this software to return to 17 * 18 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 19 * School of Computer Science 20 * Carnegie Mellon University 21 * Pittsburgh PA 15213-3890 22 * 23 * any improvements or extensions that they make and grant Carnegie the 24 * rights to redistribute these changes. 25 * 26 * $FreeBSD: src/sys/ddb/db_sym.c,v 1.32 1999/08/28 00:41:10 peter Exp $ 27 * $DragonFly: src/sys/ddb/db_sym.c,v 1.7 2006/12/23 00:27:02 swildner Exp $ 28 */ 29 30 /* 31 * Author: David B. Golub, Carnegie Mellon University 32 * Date: 7/90 33 */ 34 #include <sys/param.h> 35 #include <sys/systm.h> 36 37 #include <ddb/ddb.h> 38 #include <ddb/db_sym.h> 39 40 /* 41 * Multiple symbol tables 42 */ 43 #ifndef MAXNOSYMTABS 44 #define MAXNOSYMTABS 3 /* mach, ux, emulator */ 45 #endif 46 47 static db_symtab_t db_symtabs[MAXNOSYMTABS] = {{0,},}; 48 static int db_nsymtab = 0; 49 50 static db_symtab_t *db_last_symtab; /* where last symbol was found */ 51 52 static c_db_sym_t db_lookup ( const char *symstr); 53 static char *db_qualify (c_db_sym_t sym, char *symtabname); 54 static boolean_t db_symbol_is_ambiguous (c_db_sym_t sym); 55 static boolean_t db_line_at_pc (c_db_sym_t, char **, int *, 56 db_expr_t); 57 58 /* 59 * Add symbol table, with given name, to list of symbol tables. 60 */ 61 void 62 db_add_symbol_table(char *start, char *end, char *name, char *ref) 63 { 64 if (db_nsymtab >= MAXNOSYMTABS) { 65 kprintf ("No slots left for %s symbol table", name); 66 panic ("db_sym.c: db_add_symbol_table"); 67 } 68 69 db_symtabs[db_nsymtab].start = start; 70 db_symtabs[db_nsymtab].end = end; 71 db_symtabs[db_nsymtab].name = name; 72 db_symtabs[db_nsymtab].private = ref; 73 db_nsymtab++; 74 } 75 76 /* 77 * db_qualify("vm_map", "ux") returns "unix:vm_map". 78 * 79 * Note: return value points to static data whose content is 80 * overwritten by each call... but in practice this seems okay. 81 */ 82 static char * 83 db_qualify(c_db_sym_t sym, char *symtabname) 84 { 85 const char *symname; 86 static char tmp[256]; 87 88 db_symbol_values(sym, &symname, 0); 89 ksnprintf(tmp, sizeof(tmp), "%s:%s", symtabname, symname); 90 return tmp; 91 } 92 93 94 boolean_t 95 db_eqname(const char *src, const char *dst, int c) 96 { 97 if (!strcmp(src, dst)) 98 return (TRUE); 99 if (src[0] == c) 100 return (!strcmp(src+1,dst)); 101 return (FALSE); 102 } 103 104 boolean_t 105 db_value_of_name(const char *name, db_expr_t *valuep) 106 { 107 c_db_sym_t sym; 108 109 sym = db_lookup(name); 110 if (sym == C_DB_SYM_NULL) 111 return (FALSE); 112 db_symbol_values(sym, &name, valuep); 113 return (TRUE); 114 } 115 116 117 /* 118 * Lookup a symbol. 119 * If the symbol has a qualifier (e.g., ux:vm_map), 120 * then only the specified symbol table will be searched; 121 * otherwise, all symbol tables will be searched. 122 */ 123 static c_db_sym_t 124 db_lookup(const char *symstr) 125 { 126 c_db_sym_t sp; 127 int i; 128 int symtab_start = 0; 129 int symtab_end = db_nsymtab; 130 const char *cp; 131 132 /* 133 * Look for, remove, and remember any symbol table specifier. 134 */ 135 for (cp = symstr; *cp; cp++) { 136 if (*cp == ':') { 137 for (i = 0; i < db_nsymtab; i++) { 138 int n = strlen(db_symtabs[i].name); 139 140 if ( 141 n == (cp - symstr) && 142 strncmp(symstr, db_symtabs[i].name, n) == 0 143 ) { 144 symtab_start = i; 145 symtab_end = i + 1; 146 break; 147 } 148 } 149 if (i == db_nsymtab) { 150 db_error("invalid symbol table name"); 151 } 152 symstr = cp+1; 153 } 154 } 155 156 /* 157 * Look in the specified set of symbol tables. 158 * Return on first match. 159 */ 160 for (i = symtab_start; i < symtab_end; i++) { 161 sp = X_db_lookup(&db_symtabs[i], symstr); 162 if (sp) { 163 db_last_symtab = &db_symtabs[i]; 164 return sp; 165 } 166 } 167 return 0; 168 } 169 170 /* 171 * If TRUE, check across symbol tables for multiple occurrences 172 * of a name. Might slow things down quite a bit. 173 */ 174 static volatile boolean_t db_qualify_ambiguous_names = FALSE; 175 176 /* 177 * Does this symbol name appear in more than one symbol table? 178 * Used by db_symbol_values to decide whether to qualify a symbol. 179 */ 180 static boolean_t 181 db_symbol_is_ambiguous(c_db_sym_t sym) 182 { 183 const char *sym_name; 184 int i; 185 186 boolean_t found_once = FALSE; 187 188 if (!db_qualify_ambiguous_names) 189 return FALSE; 190 191 db_symbol_values(sym, &sym_name, 0); 192 for (i = 0; i < db_nsymtab; i++) { 193 if (X_db_lookup(&db_symtabs[i], sym_name)) { 194 if (found_once) 195 return TRUE; 196 found_once = TRUE; 197 } 198 } 199 return FALSE; 200 } 201 202 /* 203 * Find the closest symbol to val, and return its name 204 * and the difference between val and the symbol found. 205 */ 206 c_db_sym_t 207 db_search_symbol(db_addr_t val, db_strategy_t strategy, db_expr_t *offp) 208 { 209 210 unsigned int diff; 211 size_t newdiff; 212 int i; 213 c_db_sym_t ret = C_DB_SYM_NULL, sym; 214 215 newdiff = diff = ~0; 216 db_last_symtab = 0; 217 for (i = 0; i < db_nsymtab; i++) { 218 sym = X_db_search_symbol(&db_symtabs[i], val, strategy, &newdiff); 219 if (newdiff < diff) { 220 db_last_symtab = &db_symtabs[i]; 221 diff = newdiff; 222 ret = sym; 223 } 224 } 225 *offp = diff; 226 return ret; 227 } 228 229 /* 230 * Return name and value of a symbol 231 */ 232 void 233 db_symbol_values(c_db_sym_t sym, const char **namep, db_expr_t *valuep) 234 { 235 db_expr_t value; 236 237 if (sym == DB_SYM_NULL) { 238 *namep = 0; 239 return; 240 } 241 242 X_db_symbol_values(db_last_symtab, sym, namep, &value); 243 244 if (db_symbol_is_ambiguous(sym)) 245 *namep = db_qualify(sym, db_last_symtab->name); 246 if (valuep) 247 *valuep = value; 248 } 249 250 251 /* 252 * Print a the closest symbol to value 253 * 254 * After matching the symbol according to the given strategy 255 * we print it in the name+offset format, provided the symbol's 256 * value is close enough (eg smaller than db_maxoff). 257 * We also attempt to print [filename:linenum] when applicable 258 * (eg for procedure names). 259 * 260 * If we could not find a reasonable name+offset representation, 261 * then we just print the value in hex. Small values might get 262 * bogus symbol associations, e.g. 3 might get some absolute 263 * value like _INCLUDE_VERSION or something, therefore we do 264 * not accept symbols whose value is "small" (and use plain hex). 265 */ 266 267 db_expr_t db_maxoff = 0x10000; 268 269 void 270 db_printsym(db_expr_t off, db_strategy_t strategy) 271 { 272 db_expr_t d; 273 char *filename; 274 const char *name; 275 db_expr_t value; 276 int linenum; 277 c_db_sym_t cursym; 278 279 cursym = db_search_symbol(off, strategy, &d); 280 db_symbol_values(cursym, &name, &value); 281 if (name == 0) 282 value = off; 283 if (value >= DB_SMALL_VALUE_MIN && value <= DB_SMALL_VALUE_MAX) { 284 db_printf("%+#lr", (long)off); 285 return; 286 } 287 if (name == 0 || d >= (unsigned long)db_maxoff) { 288 db_printf("%#lr", (unsigned long)off); 289 return; 290 } 291 db_printf("%s", name); 292 if (d) 293 db_printf("+%+#lr", (long)d); 294 if (strategy == DB_STGY_PROC) { 295 if (db_line_at_pc(cursym, &filename, &linenum, off)) 296 db_printf(" [%s:%d]", filename, linenum); 297 } 298 } 299 300 static boolean_t 301 db_line_at_pc(c_db_sym_t sym, char **filename, int *linenum, db_expr_t pc) 302 { 303 return X_db_line_at_pc( db_last_symtab, sym, filename, linenum, pc); 304 } 305 306 int 307 db_sym_numargs(c_db_sym_t sym, int *nargp, char **argnames) 308 { 309 return X_db_sym_numargs(db_last_symtab, sym, nargp, argnames); 310 } 311