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 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include <sys/param.h> 31 #include <sys/systm.h> 32 #include <sys/cons.h> 33 #include <sys/linker.h> 34 #include <sys/kdb.h> 35 #include <sys/kernel.h> 36 #include <sys/pcpu.h> 37 #include <sys/proc.h> 38 #include <sys/reboot.h> 39 40 #include <machine/kdb.h> 41 #include <machine/pcb.h> 42 #include <machine/setjmp.h> 43 44 #include <ddb/ddb.h> 45 #include <ddb/db_command.h> 46 #include <ddb/db_sym.h> 47 48 static dbbe_init_f db_init; 49 static dbbe_trap_f db_trap; 50 static dbbe_trace_f db_trace_self_wrapper; 51 52 KDB_BACKEND(ddb, db_init, db_trace_self_wrapper, db_trap); 53 54 vm_offset_t ksym_start, ksym_end; 55 56 boolean_t 57 X_db_line_at_pc(db_symtab_t *symtab, c_db_sym_t sym, char **file, int *line, 58 db_expr_t off) 59 { 60 return (FALSE); 61 } 62 63 c_db_sym_t 64 X_db_lookup(db_symtab_t *symtab, const char *symbol) 65 { 66 c_linker_sym_t lsym; 67 Elf_Sym *sym; 68 69 if (symtab->private == NULL) { 70 return ((c_db_sym_t)((!linker_ddb_lookup(symbol, &lsym)) 71 ? lsym : NULL)); 72 } else { 73 sym = (Elf_Sym *)symtab->start; 74 while ((char *)sym < symtab->end) { 75 if (sym->st_name != 0 && 76 !strcmp(symtab->private + sym->st_name, symbol)) 77 return ((c_db_sym_t)sym); 78 sym++; 79 } 80 } 81 return (NULL); 82 } 83 84 c_db_sym_t 85 X_db_search_symbol(db_symtab_t *symtab, db_addr_t off, db_strategy_t strat, 86 db_expr_t *diffp) 87 { 88 c_linker_sym_t lsym; 89 Elf_Sym *sym, *match; 90 unsigned long diff; 91 92 if (symtab->private == NULL) { 93 if (!linker_ddb_search_symbol((caddr_t)off, &lsym, &diff)) { 94 *diffp = (db_expr_t)diff; 95 return ((c_db_sym_t)lsym); 96 } 97 return (NULL); 98 } 99 100 diff = ~0UL; 101 match = NULL; 102 for (sym = (Elf_Sym*)symtab->start; (char*)sym < symtab->end; sym++) { 103 if (sym->st_name == 0) 104 continue; 105 if (off < sym->st_value) 106 continue; 107 if (ELF_ST_TYPE(sym->st_info) != STT_OBJECT && 108 ELF_ST_TYPE(sym->st_info) != STT_FUNC && 109 ELF_ST_TYPE(sym->st_info) != STT_NOTYPE) 110 continue; 111 if ((off - sym->st_value) > diff) 112 continue; 113 if ((off - sym->st_value) < diff) { 114 diff = off - sym->st_value; 115 match = sym; 116 } else { 117 if (match == NULL) 118 match = sym; 119 else if (ELF_ST_BIND(match->st_info) == STB_LOCAL && 120 ELF_ST_BIND(sym->st_info) != STB_LOCAL) 121 match = sym; 122 } 123 if (diff == 0) { 124 if (strat == DB_STGY_PROC && 125 ELF_ST_TYPE(sym->st_info) == STT_FUNC && 126 ELF_ST_BIND(sym->st_info) != STB_LOCAL) 127 break; 128 if (strat == DB_STGY_ANY && 129 ELF_ST_BIND(sym->st_info) != STB_LOCAL) 130 break; 131 } 132 } 133 134 *diffp = (match == NULL) ? off : diff; 135 return ((c_db_sym_t)match); 136 } 137 138 boolean_t 139 X_db_sym_numargs(db_symtab_t *symtab, c_db_sym_t sym, int *nargp, 140 char **argp) 141 { 142 return (FALSE); 143 } 144 145 void 146 X_db_symbol_values(db_symtab_t *symtab, c_db_sym_t sym, const char **namep, 147 db_expr_t *valp) 148 { 149 linker_symval_t lval; 150 151 if (symtab->private == NULL) { 152 linker_ddb_symbol_values((c_linker_sym_t)sym, &lval); 153 if (namep != NULL) 154 *namep = (const char*)lval.name; 155 if (valp != NULL) 156 *valp = (db_expr_t)lval.value; 157 } else { 158 if (namep != NULL) 159 *namep = (const char *)symtab->private + 160 ((const Elf_Sym *)sym)->st_name; 161 if (valp != NULL) 162 *valp = (db_expr_t)((const Elf_Sym *)sym)->st_value; 163 } 164 } 165 166 static int 167 db_init(void) 168 { 169 uintptr_t symtab, strtab; 170 Elf_Size tabsz, strsz; 171 172 if (ksym_end > ksym_start && ksym_start != 0) { 173 symtab = ksym_start; 174 tabsz = *((Elf_Size*)symtab); 175 symtab += sizeof(Elf_Size); 176 strtab = symtab + tabsz; 177 strsz = *((Elf_Size*)strtab); 178 strtab += sizeof(Elf_Size); 179 if (strtab + strsz <= ksym_end) { 180 db_add_symbol_table((char *)symtab, 181 (char *)(symtab + tabsz), "elf", (char *)strtab); 182 } 183 } 184 db_add_symbol_table(NULL, NULL, "kld", NULL); 185 return (1); /* We're the default debugger. */ 186 } 187 188 static int 189 db_trap(int type, int code) 190 { 191 jmp_buf jb; 192 void *prev_jb; 193 boolean_t bkpt, watchpt; 194 195 /* 196 * Don't handle the trap if the console is unavailable (i.e. it 197 * is in graphics mode). 198 */ 199 if (cnunavailable()) 200 return (0); 201 202 bkpt = IS_BREAKPOINT_TRAP(type, code); 203 watchpt = IS_WATCHPOINT_TRAP(type, code); 204 205 if (db_stop_at_pc(&bkpt)) { 206 if (db_inst_count) { 207 db_printf("After %d instructions (%d loads, %d stores),\n", 208 db_inst_count, db_load_count, db_store_count); 209 } 210 prev_jb = kdb_jmpbuf(jb); 211 if (setjmp(jb) == 0) { 212 db_dot = PC_REGS(); 213 db_print_thread(); 214 if (bkpt) 215 db_printf("Breakpoint at\t"); 216 else if (watchpt) 217 db_printf("Watchpoint at\t"); 218 else 219 db_printf("Stopped at\t"); 220 db_print_loc_and_inst(db_dot); 221 } 222 db_command_loop(); 223 (void)kdb_jmpbuf(prev_jb); 224 } 225 226 db_restart_at_pc(watchpt); 227 228 return (1); 229 } 230 231 static void 232 db_trace_self_wrapper(void) 233 { 234 jmp_buf jb; 235 void *prev_jb; 236 237 prev_jb = kdb_jmpbuf(jb); 238 if (setjmp(jb) == 0) 239 db_trace_self(); 240 (void)kdb_jmpbuf(prev_jb); 241 } 242