2 * Mach Operating System
3 * Copyright (c) 1991,1990 Carnegie Mellon University
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.
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.
16 * Carnegie Mellon requests users of this software to return to
18 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
19 * School of Computer Science
20 * Carnegie Mellon University
21 * Pittsburgh PA 15213-3890
23 * any improvements or extensions that they make and grant Carnegie the
24 * rights to redistribute these changes.
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 1.8 2008/08/25 17:01:37 dillon Exp $
31 * Author: David B. Golub, Carnegie Mellon University
36 * Commands to run process.
38 #include <sys/param.h>
43 #include <ddb/db_break.h>
44 #include <ddb/db_access.h>
46 static int db_run_mode;
51 #define STEP_CONTINUE 4
52 #define STEP_INVISIBLE 5
55 static boolean_t db_sstep_print;
56 static int db_loop_count;
57 static int db_call_depth;
63 #ifndef db_set_single_step
64 extern void db_set_single_step (db_regs_t *regs);
66 #ifndef db_clear_single_step
67 extern void db_clear_single_step (db_regs_t *regs);
71 static void db_single_step (db_regs_t *regs);
75 db_stop_at_pc(boolean_t *is_breakpoint)
80 db_clear_single_step(DDB_REGS);
81 db_clear_breakpoints();
82 db_clear_watchpoints();
83 pc = PC_REGS(DDB_REGS);
85 #ifdef FIXUP_PC_AFTER_BREAK
88 * Breakpoint trap. Fix up the PC if the
89 * machine requires it.
92 pc = PC_REGS(DDB_REGS);
97 * Now check for a breakpoint at this address.
99 bkpt = db_find_breakpoint_here(pc);
101 if (--bkpt->count == 0) {
102 bkpt->count = bkpt->init_count;
103 *is_breakpoint = TRUE;
104 return (TRUE); /* stop here */
106 } else if (*is_breakpoint) {
107 #ifdef __i386__ /* XXx */
108 ddb_regs.tf_eip += 1;
109 #elif defined(__x86_64__)
110 ddb_regs.tf_rip += 1;
114 *is_breakpoint = FALSE;
116 if (db_run_mode == STEP_INVISIBLE) {
117 db_run_mode = STEP_CONTINUE;
118 return (FALSE); /* continue */
120 if (db_run_mode == STEP_COUNT) {
121 return (FALSE); /* continue */
123 if (db_run_mode == STEP_ONCE) {
124 if (--db_loop_count > 0) {
125 if (db_sstep_print) {
127 db_print_loc_and_inst(pc, DDB_REGS);
130 return (FALSE); /* continue */
133 if (db_run_mode == STEP_RETURN) {
134 db_expr_t ins = db_get_value(pc, sizeof(int), FALSE);
136 /* continue until matching return */
138 if (!inst_trap_return(ins) &&
139 (!inst_return(ins) || --db_call_depth != 0)) {
140 if (db_sstep_print) {
141 if (inst_call(ins) || inst_return(ins)) {
144 db_printf("[after %6d] ", db_inst_count);
145 for (i = db_call_depth; --i > 0; )
147 db_print_loc_and_inst(pc, DDB_REGS);
153 return (FALSE); /* continue */
156 if (db_run_mode == STEP_CALLT) {
157 db_expr_t ins = db_get_value(pc, sizeof(int), FALSE);
159 /* continue until call or return */
161 if (!inst_call(ins) &&
163 !inst_trap_return(ins)) {
164 return (FALSE); /* continue */
167 db_run_mode = STEP_NONE;
172 db_restart_at_pc(boolean_t watchpt)
174 db_addr_t pc = PC_REGS(DDB_REGS);
176 if ((db_run_mode == STEP_COUNT) ||
177 (db_run_mode == STEP_RETURN) ||
178 (db_run_mode == STEP_CALLT)) {
182 * We are about to execute this instruction,
186 ins = db_get_value(pc, sizeof(int), FALSE);
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),
196 db_load_count += inst_load(ins);
197 db_store_count += inst_store(ins);
199 #endif /* SOFTWARE_SSTEP */
202 if (db_run_mode == STEP_CONTINUE) {
203 if (watchpt || db_find_breakpoint_here(pc)) {
205 * Step over breakpoint/watchpoint.
207 db_run_mode = STEP_INVISIBLE;
208 db_set_single_step(DDB_REGS);
210 db_set_breakpoints();
211 db_set_watchpoints();
214 db_set_single_step(DDB_REGS);
220 db_single_step(db_regs_t *regs)
222 if (db_run_mode == STEP_CONTINUE) {
223 db_run_mode = STEP_INVISIBLE;
224 db_set_single_step(regs);
229 #ifdef SOFTWARE_SSTEP
231 * Software implementation of single-stepping.
232 * If your machine does not have a trace mode
233 * similar to the vax or sun ones you can use
234 * this implementation, done for the mips.
235 * Just define the above conditional and provide
236 * the functions/macros defined below.
239 * inst_branch(), returns true if the instruction might branch
241 * branch_taken(), return the address the instruction might
243 * db_getreg_val(); return the value of a user register,
244 * as indicated in the hardware instruction
245 * encoding, e.g. 8 for r8
247 * next_instr_address(pc,bd) returns the address of the first
248 * instruction following the one at "pc",
249 * which is either in the taken path of
250 * the branch (bd==1) or not. This is
251 * for machines (mips) with branch delays.
253 * A single-step may involve at most 2 breakpoints -
254 * one for branch-not-taken and one for branch taken.
255 * If one of these addresses does not already have a breakpoint,
256 * we allocate a breakpoint and save it here.
257 * These breakpoints are deleted on return.
259 db_breakpoint_t db_not_taken_bkpt = 0;
260 db_breakpoint_t db_taken_bkpt = 0;
263 db_set_single_step(db_regs_t *regs)
265 db_addr_t pc = PC_REGS(regs), brpc;
269 * User was stopped at pc, e.g. the instruction
270 * at pc was not executed.
272 inst = db_get_value(pc, sizeof(int), FALSE);
273 if (inst_branch(inst) || inst_call(inst)) {
274 brpc = branch_taken(inst, pc, regs);
275 if (brpc != pc) { /* self-branches are hopeless */
276 db_taken_bkpt = db_set_temp_breakpoint(brpc);
278 pc = next_instr_address(pc,1);
280 pc = next_instr_address(pc,0);
281 db_not_taken_bkpt = db_set_temp_breakpoint(pc);
285 db_clear_single_step(db_regs_t *regs)
288 if (db_not_taken_bkpt != 0) {
289 db_delete_temp_breakpoint(db_not_taken_bkpt);
290 db_not_taken_bkpt = 0;
292 if (db_taken_bkpt != 0) {
293 db_delete_temp_breakpoint(db_taken_bkpt);
298 #endif /* SOFTWARE_SSTEP */
300 extern int db_cmd_loop_done;
305 db_single_step_cmd(db_expr_t addr, boolean_t have_addr, db_expr_t count,
308 boolean_t print = FALSE;
316 db_run_mode = STEP_ONCE;
317 db_loop_count = count;
318 db_sstep_print = print;
323 db_cmd_loop_done = 1;
326 /* trace and print until call/return */
329 db_trace_until_call_cmd(db_expr_t addr, boolean_t have_addr, db_expr_t count,
332 boolean_t print = FALSE;
337 db_run_mode = STEP_CALLT;
338 db_sstep_print = print;
343 db_cmd_loop_done = 1;
348 db_trace_until_matching_cmd(db_expr_t addr, boolean_t have_addr,
349 db_expr_t count, char *modif)
351 boolean_t print = FALSE;
356 db_run_mode = STEP_RETURN;
358 db_sstep_print = print;
363 db_cmd_loop_done = 1;
369 db_continue_cmd(db_expr_t addr, boolean_t have_addr, db_expr_t count,
373 db_run_mode = STEP_COUNT;
375 db_run_mode = STEP_CONTINUE;
380 db_cmd_loop_done = 1;