void
db_set_single_step(db_regs_t *regs)
{
db_addr_t pc = PC_REGS(regs);
#ifndef SOFTWARE_SSTEP_EMUL
db_addr_t brpc;
u_int inst;
/*
* User was stopped at pc, e.g. the instruction
* at pc was not executed.
*/
inst = db_get_value(pc, sizeof(int), FALSE);
if (inst_branch(inst) || inst_call(inst) || inst_return(inst)) {
brpc = branch_taken(inst, pc, getreg_val, regs);
if (brpc != pc) { /* self-branches are hopeless */
db_taken_bkpt = db_set_temp_breakpoint(brpc);
}
#if 0
/* XXX this seems like a true bug, no? */
pc = next_instr_address(pc, 1);
#endif
}
#endif /*SOFTWARE_SSTEP_EMUL*/
pc = next_instr_address(pc, 0);
db_not_taken_bkpt = db_set_temp_breakpoint(pc);
}
void
db_set_single_step(db_regs_t *regs)
{
db_addr_t pc = PC_REGS(regs), brpc = pc;
bool unconditional;
unsigned int inst;
/*
* User was stopped at pc, e.g. the instruction
* at pc was not executed.
*/
inst = db_get_value(pc, sizeof(int), false);
if (inst_branch(inst) || inst_call(inst) || inst_return(inst)) {
brpc = branch_taken(inst, pc, regs);
if (brpc != pc) { /* self-branches are hopeless */
db_set_temp_breakpoint(&db_taken_bkpt, brpc);
} else
db_taken_bkpt.address = 0;
pc = next_instr_address(pc, true);
}
/*
* Check if this control flow instruction is an
* unconditional transfer.
*/
unconditional = inst_unconditional_flow_transfer(inst);
pc = next_instr_address(pc, false);
/*
* We only set the sequential breakpoint if previous
* instruction was not an unconditional change of flow
* control. If the previous instruction is an
* unconditional change of flow control, setting a
* breakpoint in the next sequential location may set
* a breakpoint in data or in another routine, which
* could screw up in either the program or the debugger.
* (Consider, for instance, that the next sequential
* instruction is the start of a routine needed by the
* debugger.)
*
* Also, don't set both the taken and not-taken breakpoints
* in the same place even if the MD code would otherwise
* have us do so.
*/
if (unconditional == false &&
db_find_breakpoint_here(pc) == 0 &&
pc != brpc)
db_set_temp_breakpoint(&db_not_taken_bkpt, pc);
else
db_not_taken_bkpt.address = 0;
}
void
db_set_task_single_step(
register db_regs_t *regs,
task_t task)
{
db_addr_t pc = PC_REGS(regs), brpc;
register unsigned int inst;
register boolean_t unconditional;
/*
* User was stopped at pc, e.g. the instruction
* at pc was not executed.
*/
inst = db_get_task_value(pc, sizeof(int), FALSE, task);
if (inst_branch(inst) || inst_call(inst)) {
extern db_expr_t getreg_val(); /* XXX -- need prototype! */
brpc = branch_taken(inst, pc, getreg_val, (unsigned char*)regs);
if (brpc != pc) { /* self-branches are hopeless */
db_taken_bkpt = db_set_temp_breakpoint(task, brpc);
} else
db_taken_bkpt = 0;
pc = next_instr_address(pc,1,task);
} else
pc = next_instr_address(pc,0,task);
/*
* check if this control flow instruction is an
* unconditional transfer
*/
unconditional = inst_unconditional_flow_transfer(inst);
/*
We only set the sequential breakpoint if previous instruction was not
an unconditional change of flow of control. If the previous instruction
is an unconditional change of flow of control, setting a breakpoint in the
next sequential location may set a breakpoint in data or in another routine,
which could screw up either the program or the debugger.
(Consider, for instance, that the next sequential instruction is the
start of a routine needed by the debugger.)
*/
if (!unconditional && db_find_breakpoint_here(task, pc) == 0 &&
(db_taken_bkpt == 0 || db_taken_bkpt->address != pc)) {
db_not_taken_bkpt = db_set_temp_breakpoint(task, pc);
} else
db_not_taken_bkpt = 0;
}
void
db_set_single_step(db_regs_t *regs)
{
db_addr_t pc = PC_REGS(regs), brpc;
unsigned inst;
/*
* User was stopped at pc, e.g. the instruction
* at pc was not executed.
*/
inst = db_get_value(pc, sizeof(int), FALSE);
if (inst_branch(inst) || inst_call(inst)) {
brpc = branch_taken(inst, pc, regs);
if (brpc != pc) { /* self-branches are hopeless */
db_taken_bkpt = db_set_temp_breakpoint(brpc);
}
pc = next_instr_address(pc,1);
}
pc = next_instr_address(pc,0);
db_not_taken_bkpt = db_set_temp_breakpoint(pc);
}
void
db_restart_at_pc(
boolean_t watchpt,
task_t task)
{
db_addr_t pc = PC_REGS(DDB_REGS);
#ifdef SOFTWARE_SSTEP
db_addr_t brpc;
#endif
if ((db_run_mode == STEP_COUNT) ||
(db_run_mode == STEP_RETURN) ||
(db_run_mode == STEP_CALLT)) {
db_expr_t ins;
/*
* We are about to execute this instruction,
* so count it now.
*/
ins = db_get_task_value(pc, sizeof(int), FALSE, task);
db_inst_count++;
db_load_count += db_inst_load(ins);
db_store_count += db_inst_store(ins);
#ifdef SOFTWARE_SSTEP
/* Account for instructions in delay slots */
brpc = next_instr_address(pc,1,task);
if ((brpc != pc) && (inst_branch(ins) || inst_call(ins))) {
/* Note: this ~assumes an instruction <= sizeof(int) */
ins = db_get_task_value(brpc, sizeof(int), FALSE, task);
db_inst_count++;
db_load_count += db_inst_load(ins);
db_store_count += db_inst_store(ins);
}
#endif /* SOFTWARE_SSTEP */
}
if (db_run_mode == STEP_CONTINUE) {
if (watchpt || db_find_breakpoint_here(task, pc)) {
/*
* Step over breakpoint/watchpoint.
*/
db_run_mode = STEP_INVISIBLE;
db_set_task_single_step(DDB_REGS, task);
} else {
db_set_breakpoints();
db_set_watchpoints();
}
} else {
db_set_task_single_step(DDB_REGS, task);
}
}
void
db_restart_at_pc(db_regs_t *regs, bool watchpt)
{
db_addr_t pc = PC_REGS(regs);
#ifdef SOFTWARE_SSTEP
db_addr_t brpc;
#endif
if ((db_run_mode == STEP_COUNT) ||
(db_run_mode == STEP_RETURN) ||
(db_run_mode == STEP_CALLT)) {
db_expr_t ins __unused;
/*
* We are about to execute this instruction,
* so count it now.
*/
ins = db_get_value(pc, sizeof(int), false);
db_inst_count++;
db_load_count += inst_load(ins);
db_store_count += inst_store(ins);
#ifdef SOFTWARE_SSTEP
/*
* Account for instructions in delay slots.
*/
brpc = next_instr_address(pc, true);
if ((brpc != pc) &&
(inst_branch(ins) || inst_call(ins) || inst_return(ins))) {
ins = db_get_value(brpc, sizeof(int), false);
db_inst_count++;
db_load_count += inst_load(ins);
db_store_count += inst_store(ins);
}
#endif
}
if (db_run_mode == STEP_CONTINUE) {
if (watchpt || db_find_breakpoint_here(pc)) {
/*
* Step over breakpoint/watchpoint.
*/
db_run_mode = STEP_INVISIBLE;
db_set_single_step(regs);
} else {
db_set_breakpoints();
db_set_watchpoints();
}
} else {
db_set_single_step(regs);
}
}
void
db_restart_at_pc(boolean_t watchpt)
{
db_addr_t pc = PC_REGS(DDB_REGS);
if ((db_run_mode == STEP_COUNT) ||
(db_run_mode == STEP_RETURN) ||
(db_run_mode == STEP_CALLT)) {
db_expr_t ins __unused; /* seems used but gcc thinks not */
/*
* We are about to execute this instruction,
* so count it now.
*/
ins = db_get_value(pc, sizeof(int), FALSE);
db_inst_count++;
db_load_count += inst_load(ins);
db_store_count += inst_store(ins);
#ifdef SOFTWARE_SSTEP
/* XXX works on mips, but... */
if (inst_branch(ins) || inst_call(ins)) {
ins = db_get_value(next_instr_address(pc,1),
sizeof(int), FALSE);
db_inst_count++;
db_load_count += inst_load(ins);
db_store_count += inst_store(ins);
}
#endif /* SOFTWARE_SSTEP */
}
if (db_run_mode == STEP_CONTINUE) {
if (watchpt || db_find_breakpoint_here(pc)) {
/*
* Step over breakpoint/watchpoint.
*/
db_run_mode = STEP_INVISIBLE;
db_set_single_step(DDB_REGS);
} else {
db_set_breakpoints();
db_set_watchpoints();
}
} else {
db_set_single_step(DDB_REGS);
}
}
