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 #include <sys/sysctl.h> 40 41 #include <machine/kdb.h> 42 #include <machine/pcb.h> 43 #include <machine/setjmp.h> 44 45 #include <ddb/ddb.h> 46 #include <ddb/db_command.h> 47 #include <ddb/db_sym.h> 48 49 SYSCTL_NODE(_debug, OID_AUTO, ddb, CTLFLAG_RW, 0, "DDB settings"); 50 51 static dbbe_init_f db_init; 52 static dbbe_trap_f db_trap; 53 static dbbe_trace_f db_trace_self_wrapper; 54 55 KDB_BACKEND(ddb, db_init, db_trace_self_wrapper, db_trap); 56 57 vm_offset_t ksym_start, ksym_end; 58 59 boolean_t 60 X_db_line_at_pc(db_symtab_t *symtab, c_db_sym_t sym, char **file, int *line, 61 db_expr_t off) 62 { 63 return (FALSE); 64 } 65 66 c_db_sym_t 67 X_db_lookup(db_symtab_t *symtab, const char *symbol) 68 { 69 c_linker_sym_t lsym; 70 Elf_Sym *sym; 71 72 if (symtab->private == NULL) { 73 return ((c_db_sym_t)((!linker_ddb_lookup(symbol, &lsym)) 74 ? lsym : NULL)); 75 } else { 76 sym = (Elf_Sym *)symtab->start; 77 while ((char *)sym < symtab->end) { 78 if (sym->st_name != 0 && 79 !strcmp(symtab->private + sym->st_name, symbol)) 80 return ((c_db_sym_t)sym); 81 sym++; 82 } 83 } 84 return (NULL); 85 } 86 87 c_db_sym_t 88 X_db_search_symbol(db_symtab_t *symtab, db_addr_t off, db_strategy_t strat, 89 db_expr_t *diffp) 90 { 91 c_linker_sym_t lsym; 92 Elf_Sym *sym, *match; 93 unsigned long diff; 94 95 if (symtab->private == NULL) { 96 if (!linker_ddb_search_symbol((caddr_t)off, &lsym, &diff)) { 97 *diffp = (db_expr_t)diff; 98 return ((c_db_sym_t)lsym); 99 } 100 return (NULL); 101 } 102 103 diff = ~0UL; 104 match = NULL; 105 for (sym = (Elf_Sym*)symtab->start; (char*)sym < symtab->end; sym++) { 106 if (sym->st_name == 0) 107 continue; 108 if (off < sym->st_value) 109 continue; 110 if (ELF_ST_TYPE(sym->st_info) != STT_OBJECT && 111 ELF_ST_TYPE(sym->st_info) != STT_FUNC && 112 ELF_ST_TYPE(sym->st_info) != STT_NOTYPE) 113 continue; 114 if ((off - sym->st_value) > diff) 115 continue; 116 if ((off - sym->st_value) < diff) { 117 diff = off - sym->st_value; 118 match = sym; 119 } else { 120 if (match == NULL) 121 match = sym; 122 else if (ELF_ST_BIND(match->st_info) == STB_LOCAL && 123 ELF_ST_BIND(sym->st_info) != STB_LOCAL) 124 match = sym; 125 } 126 if (diff == 0) { 127 if (strat == DB_STGY_PROC && 128 ELF_ST_TYPE(sym->st_info) == STT_FUNC && 129 ELF_ST_BIND(sym->st_info) != STB_LOCAL) 130 break; 131 if (strat == DB_STGY_ANY && 132 ELF_ST_BIND(sym->st_info) != STB_LOCAL) 133 break; 134 } 135 } 136 137 *diffp = (match == NULL) ? off : diff; 138 return ((c_db_sym_t)match); 139 } 140 141 boolean_t 142 X_db_sym_numargs(db_symtab_t *symtab, c_db_sym_t sym, int *nargp, 143 char **argp) 144 { 145 return (FALSE); 146 } 147 148 void 149 X_db_symbol_values(db_symtab_t *symtab, c_db_sym_t sym, const char **namep, 150 db_expr_t *valp) 151 { 152 linker_symval_t lval; 153 154 if (symtab->private == NULL) { 155 linker_ddb_symbol_values((c_linker_sym_t)sym, &lval); 156 if (namep != NULL) 157 *namep = (const char*)lval.name; 158 if (valp != NULL) 159 *valp = (db_expr_t)lval.value; 160 } else { 161 if (namep != NULL) 162 *namep = (const char *)symtab->private + 163 ((const Elf_Sym *)sym)->st_name; 164 if (valp != NULL) 165 *valp = (db_expr_t)((const Elf_Sym *)sym)->st_value; 166 } 167 } 168 169 static int 170 db_init(void) 171 { 172 uintptr_t symtab, strtab; 173 Elf_Size tabsz, strsz; 174 175 db_command_init(); 176 if (ksym_end > ksym_start && ksym_start != 0) { 177 symtab = ksym_start; 178 tabsz = *((Elf_Size*)symtab); 179 symtab += sizeof(Elf_Size); 180 strtab = symtab + tabsz; 181 strsz = *((Elf_Size*)strtab); 182 strtab += sizeof(Elf_Size); 183 if (strtab + strsz <= ksym_end) { 184 db_add_symbol_table((char *)symtab, 185 (char *)(symtab + tabsz), "elf", (char *)strtab); 186 } 187 } 188 db_add_symbol_table(NULL, NULL, "kld", NULL); 189 return (1); /* We're the default debugger. */ 190 } 191 192 static int 193 db_trap(int type, int code) 194 { 195 jmp_buf jb; 196 void *prev_jb; 197 boolean_t bkpt, watchpt; 198 const char *why; 199 200 /* 201 * Don't handle the trap if the console is unavailable (i.e. it 202 * is in graphics mode). 203 */ 204 if (cnunavailable()) 205 return (0); 206 207 bkpt = IS_BREAKPOINT_TRAP(type, code); 208 watchpt = IS_WATCHPOINT_TRAP(type, code); 209 210 if (db_stop_at_pc(&bkpt)) { 211 if (db_inst_count) { 212 db_printf("After %d instructions (%d loads, %d stores),\n", 213 db_inst_count, db_load_count, db_store_count); 214 } 215 prev_jb = kdb_jmpbuf(jb); 216 if (setjmp(jb) == 0) { 217 db_dot = PC_REGS(); 218 db_print_thread(); 219 if (bkpt) 220 db_printf("Breakpoint at\t"); 221 else if (watchpt) 222 db_printf("Watchpoint at\t"); 223 else 224 db_printf("Stopped at\t"); 225 db_print_loc_and_inst(db_dot); 226 } 227 why = kdb_why; 228 db_script_kdbenter(why != KDB_WHY_UNSET ? why : "unknown"); 229 db_command_loop(); 230 (void)kdb_jmpbuf(prev_jb); 231 } 232 233 db_restart_at_pc(watchpt); 234 235 return (1); 236 } 237 238 static void 239 db_trace_self_wrapper(void) 240 { 241 jmp_buf jb; 242 void *prev_jb; 243 244 prev_jb = kdb_jmpbuf(jb); 245 if (setjmp(jb) == 0) 246 db_trace_self(); 247 (void)kdb_jmpbuf(prev_jb); 248 } 249