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 static dbbe_trace_thread_f db_trace_thread_wrapper; 55 56 KDB_BACKEND(ddb, db_init, db_trace_self_wrapper, db_trace_thread_wrapper, 57 db_trap); 58 59 vm_offset_t ksym_start, ksym_end; 60 61 boolean_t 62 X_db_line_at_pc(db_symtab_t *symtab, c_db_sym_t sym, char **file, int *line, 63 db_expr_t off) 64 { 65 return (FALSE); 66 } 67 68 c_db_sym_t 69 X_db_lookup(db_symtab_t *symtab, const char *symbol) 70 { 71 c_linker_sym_t lsym; 72 Elf_Sym *sym; 73 74 if (symtab->private == NULL) { 75 return ((c_db_sym_t)((!linker_ddb_lookup(symbol, &lsym)) 76 ? lsym : NULL)); 77 } else { 78 sym = (Elf_Sym *)symtab->start; 79 while ((char *)sym < symtab->end) { 80 if (sym->st_name != 0 && 81 !strcmp(symtab->private + sym->st_name, symbol)) 82 return ((c_db_sym_t)sym); 83 sym++; 84 } 85 } 86 return (NULL); 87 } 88 89 c_db_sym_t 90 X_db_search_symbol(db_symtab_t *symtab, db_addr_t off, db_strategy_t strat, 91 db_expr_t *diffp) 92 { 93 c_linker_sym_t lsym; 94 Elf_Sym *sym, *match; 95 unsigned long diff; 96 97 if (symtab->private == NULL) { 98 if (!linker_ddb_search_symbol((caddr_t)off, &lsym, &diff)) { 99 *diffp = (db_expr_t)diff; 100 return ((c_db_sym_t)lsym); 101 } 102 return (NULL); 103 } 104 105 diff = ~0UL; 106 match = NULL; 107 for (sym = (Elf_Sym*)symtab->start; (char*)sym < symtab->end; sym++) { 108 if (sym->st_name == 0) 109 continue; 110 if (off < sym->st_value) 111 continue; 112 if (ELF_ST_TYPE(sym->st_info) != STT_OBJECT && 113 ELF_ST_TYPE(sym->st_info) != STT_FUNC && 114 ELF_ST_TYPE(sym->st_info) != STT_NOTYPE) 115 continue; 116 if ((off - sym->st_value) > diff) 117 continue; 118 if ((off - sym->st_value) < diff) { 119 diff = off - sym->st_value; 120 match = sym; 121 } else { 122 if (match == NULL) 123 match = sym; 124 else if (ELF_ST_BIND(match->st_info) == STB_LOCAL && 125 ELF_ST_BIND(sym->st_info) != STB_LOCAL) 126 match = sym; 127 } 128 if (diff == 0) { 129 if (strat == DB_STGY_PROC && 130 ELF_ST_TYPE(sym->st_info) == STT_FUNC && 131 ELF_ST_BIND(sym->st_info) != STB_LOCAL) 132 break; 133 if (strat == DB_STGY_ANY && 134 ELF_ST_BIND(sym->st_info) != STB_LOCAL) 135 break; 136 } 137 } 138 139 *diffp = (match == NULL) ? off : diff; 140 return ((c_db_sym_t)match); 141 } 142 143 boolean_t 144 X_db_sym_numargs(db_symtab_t *symtab, c_db_sym_t sym, int *nargp, 145 char **argp) 146 { 147 return (FALSE); 148 } 149 150 void 151 X_db_symbol_values(db_symtab_t *symtab, c_db_sym_t sym, const char **namep, 152 db_expr_t *valp) 153 { 154 linker_symval_t lval; 155 156 if (symtab->private == NULL) { 157 linker_ddb_symbol_values((c_linker_sym_t)sym, &lval); 158 if (namep != NULL) 159 *namep = (const char*)lval.name; 160 if (valp != NULL) 161 *valp = (db_expr_t)lval.value; 162 } else { 163 if (namep != NULL) 164 *namep = (const char *)symtab->private + 165 ((const Elf_Sym *)sym)->st_name; 166 if (valp != NULL) 167 *valp = (db_expr_t)((const Elf_Sym *)sym)->st_value; 168 } 169 } 170 171 static int 172 db_init(void) 173 { 174 uintptr_t symtab, strtab; 175 Elf_Size tabsz, strsz; 176 177 db_command_init(); 178 if (ksym_end > ksym_start && ksym_start != 0) { 179 symtab = ksym_start; 180 tabsz = *((Elf_Size*)symtab); 181 symtab += sizeof(Elf_Size); 182 strtab = symtab + tabsz; 183 strsz = *((Elf_Size*)strtab); 184 strtab += sizeof(Elf_Size); 185 if (strtab + strsz <= ksym_end) { 186 db_add_symbol_table((char *)symtab, 187 (char *)(symtab + tabsz), "elf", (char *)strtab); 188 } 189 } 190 db_add_symbol_table(NULL, NULL, "kld", NULL); 191 return (1); /* We're the default debugger. */ 192 } 193 194 static int 195 db_trap(int type, int code) 196 { 197 jmp_buf jb; 198 void *prev_jb; 199 boolean_t bkpt, watchpt; 200 const char *why; 201 202 /* 203 * Don't handle the trap if the console is unavailable (i.e. it 204 * is in graphics mode). 205 */ 206 if (cnunavailable()) 207 return (0); 208 209 bkpt = IS_BREAKPOINT_TRAP(type, code); 210 watchpt = IS_WATCHPOINT_TRAP(type, code); 211 212 if (db_stop_at_pc(&bkpt)) { 213 if (db_inst_count) { 214 db_printf("After %d instructions (%d loads, %d stores),\n", 215 db_inst_count, db_load_count, db_store_count); 216 } 217 prev_jb = kdb_jmpbuf(jb); 218 if (setjmp(jb) == 0) { 219 db_dot = PC_REGS(); 220 db_print_thread(); 221 if (bkpt) 222 db_printf("Breakpoint at\t"); 223 else if (watchpt) 224 db_printf("Watchpoint at\t"); 225 else 226 db_printf("Stopped at\t"); 227 db_print_loc_and_inst(db_dot); 228 } 229 why = kdb_why; 230 db_script_kdbenter(why != KDB_WHY_UNSET ? why : "unknown"); 231 db_command_loop(); 232 (void)kdb_jmpbuf(prev_jb); 233 } 234 235 db_restart_at_pc(watchpt); 236 237 return (1); 238 } 239 240 static void 241 db_trace_self_wrapper(void) 242 { 243 jmp_buf jb; 244 void *prev_jb; 245 246 prev_jb = kdb_jmpbuf(jb); 247 if (setjmp(jb) == 0) 248 db_trace_self(); 249 (void)kdb_jmpbuf(prev_jb); 250 } 251 252 static void 253 db_trace_thread_wrapper(struct thread *td) 254 { 255 jmp_buf jb; 256 void *prev_jb; 257 258 prev_jb = kdb_jmpbuf(jb); 259 if (setjmp(jb) == 0) 260 db_trace_thread(td, -1); 261 (void)kdb_jmpbuf(prev_jb); 262 } 263