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_run.c,v 1.18 1999/08/28 00:41:10 peter Exp $ 27 * $DragonFly: src/sys/ddb/db_run.c,v 1.6 2003/11/15 21:05:40 dillon Exp $ 28 */ 29 30 /* 31 * Author: David B. Golub, Carnegie Mellon University 32 * Date: 7/90 33 */ 34 35 /* 36 * Commands to run process. 37 */ 38 #include <sys/param.h> 39 40 #include <vm/vm.h> 41 42 #include <ddb/ddb.h> 43 #include <ddb/db_break.h> 44 #include <ddb/db_access.h> 45 46 static int db_run_mode; 47 #define STEP_NONE 0 48 #define STEP_ONCE 1 49 #define STEP_RETURN 2 50 #define STEP_CALLT 3 51 #define STEP_CONTINUE 4 52 #define STEP_INVISIBLE 5 53 #define STEP_COUNT 6 54 55 static boolean_t db_sstep_print; 56 static int db_loop_count; 57 static int db_call_depth; 58 59 int db_inst_count; 60 int db_load_count; 61 int db_store_count; 62 63 #ifndef db_set_single_step 64 extern void db_set_single_step (db_regs_t *regs); 65 #endif 66 #ifndef db_clear_single_step 67 extern void db_clear_single_step (db_regs_t *regs); 68 #endif 69 70 #ifdef notused 71 static void db_single_step (db_regs_t *regs); 72 #endif 73 74 boolean_t 75 db_stop_at_pc(is_breakpoint) 76 boolean_t *is_breakpoint; 77 { 78 db_addr_t pc; 79 db_breakpoint_t bkpt; 80 81 db_clear_single_step(DDB_REGS); 82 db_clear_breakpoints(); 83 db_clear_watchpoints(); 84 pc = PC_REGS(DDB_REGS); 85 86 #ifdef FIXUP_PC_AFTER_BREAK 87 if (*is_breakpoint) { 88 /* 89 * Breakpoint trap. Fix up the PC if the 90 * machine requires it. 91 */ 92 FIXUP_PC_AFTER_BREAK 93 pc = PC_REGS(DDB_REGS); 94 } 95 #endif 96 97 /* 98 * Now check for a breakpoint at this address. 99 */ 100 bkpt = db_find_breakpoint_here(pc); 101 if (bkpt) { 102 if (--bkpt->count == 0) { 103 bkpt->count = bkpt->init_count; 104 *is_breakpoint = TRUE; 105 return (TRUE); /* stop here */ 106 } 107 } else if (*is_breakpoint) { 108 #ifdef __i386__ /* XXx */ 109 ddb_regs.tf_eip += 1; 110 #endif 111 } 112 113 *is_breakpoint = FALSE; 114 115 if (db_run_mode == STEP_INVISIBLE) { 116 db_run_mode = STEP_CONTINUE; 117 return (FALSE); /* continue */ 118 } 119 if (db_run_mode == STEP_COUNT) { 120 return (FALSE); /* continue */ 121 } 122 if (db_run_mode == STEP_ONCE) { 123 if (--db_loop_count > 0) { 124 if (db_sstep_print) { 125 db_printf("\t\t"); 126 db_print_loc_and_inst(pc, DDB_REGS); 127 db_printf("\n"); 128 } 129 return (FALSE); /* continue */ 130 } 131 } 132 if (db_run_mode == STEP_RETURN) { 133 db_expr_t ins = db_get_value(pc, sizeof(int), FALSE); 134 135 /* continue until matching return */ 136 137 if (!inst_trap_return(ins) && 138 (!inst_return(ins) || --db_call_depth != 0)) { 139 if (db_sstep_print) { 140 if (inst_call(ins) || inst_return(ins)) { 141 int i; 142 143 db_printf("[after %6d] ", db_inst_count); 144 for (i = db_call_depth; --i > 0; ) 145 db_printf(" "); 146 db_print_loc_and_inst(pc, DDB_REGS); 147 db_printf("\n"); 148 } 149 } 150 if (inst_call(ins)) 151 db_call_depth++; 152 return (FALSE); /* continue */ 153 } 154 } 155 if (db_run_mode == STEP_CALLT) { 156 db_expr_t ins = db_get_value(pc, sizeof(int), FALSE); 157 158 /* continue until call or return */ 159 160 if (!inst_call(ins) && 161 !inst_return(ins) && 162 !inst_trap_return(ins)) { 163 return (FALSE); /* continue */ 164 } 165 } 166 db_run_mode = STEP_NONE; 167 return (TRUE); 168 } 169 170 void 171 db_restart_at_pc(watchpt) 172 boolean_t watchpt; 173 { 174 db_addr_t pc = PC_REGS(DDB_REGS); 175 176 if ((db_run_mode == STEP_COUNT) || 177 (db_run_mode == STEP_RETURN) || 178 (db_run_mode == STEP_CALLT)) { 179 db_expr_t ins; 180 181 /* 182 * We are about to execute this instruction, 183 * so count it now. 184 */ 185 186 ins = db_get_value(pc, sizeof(int), FALSE); 187 db_inst_count++; 188 db_load_count += inst_load(ins); 189 db_store_count += inst_store(ins); 190 #ifdef SOFTWARE_SSTEP 191 /* XXX works on mips, but... */ 192 if (inst_branch(ins) || inst_call(ins)) { 193 ins = db_get_value(next_instr_address(pc,1), 194 sizeof(int), FALSE); 195 db_inst_count++; 196 db_load_count += inst_load(ins); 197 db_store_count += inst_store(ins); 198 } 199 #endif /* SOFTWARE_SSTEP */ 200 } 201 202 if (db_run_mode == STEP_CONTINUE) { 203 if (watchpt || db_find_breakpoint_here(pc)) { 204 /* 205 * Step over breakpoint/watchpoint. 206 */ 207 db_run_mode = STEP_INVISIBLE; 208 db_set_single_step(DDB_REGS); 209 } else { 210 db_set_breakpoints(); 211 db_set_watchpoints(); 212 } 213 } else { 214 db_set_single_step(DDB_REGS); 215 } 216 } 217 218 #ifdef notused 219 static void 220 db_single_step(regs) 221 db_regs_t *regs; 222 { 223 if (db_run_mode == STEP_CONTINUE) { 224 db_run_mode = STEP_INVISIBLE; 225 db_set_single_step(regs); 226 } 227 } 228 #endif 229 230 #ifdef SOFTWARE_SSTEP 231 /* 232 * Software implementation of single-stepping. 233 * If your machine does not have a trace mode 234 * similar to the vax or sun ones you can use 235 * this implementation, done for the mips. 236 * Just define the above conditional and provide 237 * the functions/macros defined below. 238 * 239 * extern boolean_t 240 * inst_branch(), returns true if the instruction might branch 241 * extern unsigned 242 * branch_taken(), return the address the instruction might 243 * branch to 244 * db_getreg_val(); return the value of a user register, 245 * as indicated in the hardware instruction 246 * encoding, e.g. 8 for r8 247 * 248 * next_instr_address(pc,bd) returns the address of the first 249 * instruction following the one at "pc", 250 * which is either in the taken path of 251 * the branch (bd==1) or not. This is 252 * for machines (mips) with branch delays. 253 * 254 * A single-step may involve at most 2 breakpoints - 255 * one for branch-not-taken and one for branch taken. 256 * If one of these addresses does not already have a breakpoint, 257 * we allocate a breakpoint and save it here. 258 * These breakpoints are deleted on return. 259 */ 260 db_breakpoint_t db_not_taken_bkpt = 0; 261 db_breakpoint_t db_taken_bkpt = 0; 262 263 void 264 db_set_single_step(regs) 265 db_regs_t *regs; 266 { 267 db_addr_t pc = PC_REGS(regs), brpc; 268 unsigned inst; 269 270 /* 271 * User was stopped at pc, e.g. the instruction 272 * at pc was not executed. 273 */ 274 inst = db_get_value(pc, sizeof(int), FALSE); 275 if (inst_branch(inst) || inst_call(inst)) { 276 brpc = branch_taken(inst, pc, regs); 277 if (brpc != pc) { /* self-branches are hopeless */ 278 db_taken_bkpt = db_set_temp_breakpoint(brpc); 279 } 280 pc = next_instr_address(pc,1); 281 } 282 pc = next_instr_address(pc,0); 283 db_not_taken_bkpt = db_set_temp_breakpoint(pc); 284 } 285 286 void 287 db_clear_single_step(regs) 288 db_regs_t *regs; 289 { 290 291 if (db_not_taken_bkpt != 0) { 292 db_delete_temp_breakpoint(db_not_taken_bkpt); 293 db_not_taken_bkpt = 0; 294 } 295 if (db_taken_bkpt != 0) { 296 db_delete_temp_breakpoint(db_taken_bkpt); 297 db_taken_bkpt = 0; 298 } 299 } 300 301 #endif /* SOFTWARE_SSTEP */ 302 303 extern int db_cmd_loop_done; 304 305 /* single-step */ 306 /*ARGSUSED*/ 307 void 308 db_single_step_cmd(addr, have_addr, count, modif) 309 db_expr_t addr; 310 boolean_t have_addr; 311 db_expr_t count; 312 char * modif; 313 { 314 boolean_t print = FALSE; 315 316 if (count == -1) 317 count = 1; 318 319 if (modif[0] == 'p') 320 print = TRUE; 321 322 db_run_mode = STEP_ONCE; 323 db_loop_count = count; 324 db_sstep_print = print; 325 db_inst_count = 0; 326 db_load_count = 0; 327 db_store_count = 0; 328 329 db_cmd_loop_done = 1; 330 } 331 332 /* trace and print until call/return */ 333 /*ARGSUSED*/ 334 void 335 db_trace_until_call_cmd(addr, have_addr, count, modif) 336 db_expr_t addr; 337 boolean_t have_addr; 338 db_expr_t count; 339 char * modif; 340 { 341 boolean_t print = FALSE; 342 343 if (modif[0] == 'p') 344 print = TRUE; 345 346 db_run_mode = STEP_CALLT; 347 db_sstep_print = print; 348 db_inst_count = 0; 349 db_load_count = 0; 350 db_store_count = 0; 351 352 db_cmd_loop_done = 1; 353 } 354 355 /*ARGSUSED*/ 356 void 357 db_trace_until_matching_cmd(addr, have_addr, count, modif) 358 db_expr_t addr; 359 boolean_t have_addr; 360 db_expr_t count; 361 char * modif; 362 { 363 boolean_t print = FALSE; 364 365 if (modif[0] == 'p') 366 print = TRUE; 367 368 db_run_mode = STEP_RETURN; 369 db_call_depth = 1; 370 db_sstep_print = print; 371 db_inst_count = 0; 372 db_load_count = 0; 373 db_store_count = 0; 374 375 db_cmd_loop_done = 1; 376 } 377 378 /* continue */ 379 /*ARGSUSED*/ 380 void 381 db_continue_cmd(addr, have_addr, count, modif) 382 db_expr_t addr; 383 boolean_t have_addr; 384 db_expr_t count; 385 char * modif; 386 { 387 if (modif[0] == 'c') 388 db_run_mode = STEP_COUNT; 389 else 390 db_run_mode = STEP_CONTINUE; 391 db_inst_count = 0; 392 db_load_count = 0; 393 db_store_count = 0; 394 395 db_cmd_loop_done = 1; 396 } 397