freebsd-skq/sys/ddb/db_run.c
marcel aae5483213 Mega update for the KDB framework: turn DDB into a KDB backend.
Most of the changes are a direct result of adding thread awareness.
Typically, DDB_REGS is gone. All registers are taken from the
trapframe and backtraces use the PCB based contexts. DDB_REGS was
defined to be a trapframe on all platforms anyway.
Thread awareness introduces the following new commands:
	thread X	switch to thread X (where X is the TID),
	show threads	list all threads.

The backtrace code has been made more flexible so that one can
create backtraces for any thread by giving the thread ID as an
argument to trace.

With this change, ia64 has support for breakpoints.
2004-07-10 23:47:20 +00:00

383 lines
8.3 KiB
C

/*
* Mach Operating System
* Copyright (c) 1991,1990 Carnegie Mellon University
* All Rights Reserved.
*
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie the
* rights to redistribute these changes.
*/
/*
* Author: David B. Golub, Carnegie Mellon University
* Date: 7/90
*/
/*
* Commands to run process.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/kdb.h>
#include <machine/kdb.h>
#include <machine/pcb.h>
#include <vm/vm.h>
#include <ddb/ddb.h>
#include <ddb/db_break.h>
#include <ddb/db_access.h>
static int db_run_mode;
#define STEP_NONE 0
#define STEP_ONCE 1
#define STEP_RETURN 2
#define STEP_CALLT 3
#define STEP_CONTINUE 4
#define STEP_INVISIBLE 5
#define STEP_COUNT 6
static boolean_t db_sstep_print;
static int db_loop_count;
static int db_call_depth;
int db_inst_count;
int db_load_count;
int db_store_count;
#ifndef db_set_single_step
void db_set_single_step(void);
#endif
#ifndef db_clear_single_step
void db_clear_single_step(void);
#endif
boolean_t
db_stop_at_pc(is_breakpoint)
boolean_t *is_breakpoint;
{
register db_addr_t pc;
register db_breakpoint_t bkpt;
db_clear_single_step();
db_clear_breakpoints();
db_clear_watchpoints();
pc = PC_REGS();
#ifdef FIXUP_PC_AFTER_BREAK
if (*is_breakpoint) {
/*
* Breakpoint trap. Fix up the PC if the
* machine requires it.
*/
FIXUP_PC_AFTER_BREAK
pc = PC_REGS();
}
#endif
/*
* Now check for a breakpoint at this address.
*/
bkpt = db_find_breakpoint_here(pc);
if (bkpt) {
if (--bkpt->count == 0) {
bkpt->count = bkpt->init_count;
*is_breakpoint = TRUE;
return (TRUE); /* stop here */
}
} else if (*is_breakpoint) {
#ifdef BKPT_SKIP
BKPT_SKIP;
#endif
}
*is_breakpoint = FALSE;
if (db_run_mode == STEP_INVISIBLE) {
db_run_mode = STEP_CONTINUE;
return (FALSE); /* continue */
}
if (db_run_mode == STEP_COUNT) {
return (FALSE); /* continue */
}
if (db_run_mode == STEP_ONCE) {
if (--db_loop_count > 0) {
if (db_sstep_print) {
db_printf("\t\t");
db_print_loc_and_inst(pc);
db_printf("\n");
}
return (FALSE); /* continue */
}
}
if (db_run_mode == STEP_RETURN) {
/* continue until matching return */
db_expr_t ins;
ins = db_get_value(pc, sizeof(int), FALSE);
if (!inst_trap_return(ins) &&
(!inst_return(ins) || --db_call_depth != 0)) {
if (db_sstep_print) {
if (inst_call(ins) || inst_return(ins)) {
register int i;
db_printf("[after %6d] ", db_inst_count);
for (i = db_call_depth; --i > 0; )
db_printf(" ");
db_print_loc_and_inst(pc);
db_printf("\n");
}
}
if (inst_call(ins))
db_call_depth++;
return (FALSE); /* continue */
}
}
if (db_run_mode == STEP_CALLT) {
/* continue until call or return */
db_expr_t ins;
ins = db_get_value(pc, sizeof(int), FALSE);
if (!inst_call(ins) &&
!inst_return(ins) &&
!inst_trap_return(ins)) {
return (FALSE); /* continue */
}
}
db_run_mode = STEP_NONE;
return (TRUE);
}
void
db_restart_at_pc(watchpt)
boolean_t watchpt;
{
register db_addr_t pc = PC_REGS();
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_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();
} else {
db_set_breakpoints();
db_set_watchpoints();
}
} else {
db_set_single_step();
}
}
#ifdef SOFTWARE_SSTEP
/*
* Software implementation of single-stepping.
* If your machine does not have a trace mode
* similar to the vax or sun ones you can use
* this implementation, done for the mips.
* Just define the above conditional and provide
* the functions/macros defined below.
*
* extern boolean_t
* inst_branch(), returns true if the instruction might branch
* extern unsigned
* branch_taken(), return the address the instruction might
* branch to
* db_getreg_val(); return the value of a user register,
* as indicated in the hardware instruction
* encoding, e.g. 8 for r8
*
* next_instr_address(pc,bd) returns the address of the first
* instruction following the one at "pc",
* which is either in the taken path of
* the branch (bd==1) or not. This is
* for machines (mips) with branch delays.
*
* A single-step may involve at most 2 breakpoints -
* one for branch-not-taken and one for branch taken.
* If one of these addresses does not already have a breakpoint,
* we allocate a breakpoint and save it here.
* These breakpoints are deleted on return.
*/
db_breakpoint_t db_not_taken_bkpt = 0;
db_breakpoint_t db_taken_bkpt = 0;
void
db_set_single_step(void)
{
db_addr_t pc = PC_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);
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_clear_single_step(void)
{
if (db_not_taken_bkpt != 0) {
db_delete_temp_breakpoint(db_not_taken_bkpt);
db_not_taken_bkpt = 0;
}
if (db_taken_bkpt != 0) {
db_delete_temp_breakpoint(db_taken_bkpt);
db_taken_bkpt = 0;
}
}
#endif /* SOFTWARE_SSTEP */
extern int db_cmd_loop_done;
/* single-step */
/*ARGSUSED*/
void
db_single_step_cmd(addr, have_addr, count, modif)
db_expr_t addr;
boolean_t have_addr;
db_expr_t count;
char * modif;
{
boolean_t print = FALSE;
if (count == -1)
count = 1;
if (modif[0] == 'p')
print = TRUE;
db_run_mode = STEP_ONCE;
db_loop_count = count;
db_sstep_print = print;
db_inst_count = 0;
db_load_count = 0;
db_store_count = 0;
db_cmd_loop_done = 1;
}
/* trace and print until call/return */
/*ARGSUSED*/
void
db_trace_until_call_cmd(addr, have_addr, count, modif)
db_expr_t addr;
boolean_t have_addr;
db_expr_t count;
char * modif;
{
boolean_t print = FALSE;
if (modif[0] == 'p')
print = TRUE;
db_run_mode = STEP_CALLT;
db_sstep_print = print;
db_inst_count = 0;
db_load_count = 0;
db_store_count = 0;
db_cmd_loop_done = 1;
}
/*ARGSUSED*/
void
db_trace_until_matching_cmd(addr, have_addr, count, modif)
db_expr_t addr;
boolean_t have_addr;
db_expr_t count;
char * modif;
{
boolean_t print = FALSE;
if (modif[0] == 'p')
print = TRUE;
db_run_mode = STEP_RETURN;
db_call_depth = 1;
db_sstep_print = print;
db_inst_count = 0;
db_load_count = 0;
db_store_count = 0;
db_cmd_loop_done = 1;
}
/* continue */
/*ARGSUSED*/
void
db_continue_cmd(addr, have_addr, count, modif)
db_expr_t addr;
boolean_t have_addr;
db_expr_t count;
char * modif;
{
if (modif[0] == 'c')
db_run_mode = STEP_COUNT;
else
db_run_mode = STEP_CONTINUE;
db_inst_count = 0;
db_load_count = 0;
db_store_count = 0;
db_cmd_loop_done = 1;
}