/*      $NetBSD: db_break.c,v 1.26 2007/02/22 06:41:00 thorpej Exp $    */

/*
 * 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 "AS IS"
 * 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
 */

/*
 * Breakpoints.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: db_break.c,v 1.26 2007/02/22 06:41:00 thorpej Exp $");

#include <sys/param.h>
#include <sys/proc.h>

#include <machine/db_machdep.h>         /* type definitions */

#include <ddb/db_lex.h>
#include <ddb/db_access.h>
#include <ddb/db_sym.h>
#include <ddb/db_break.h>
#include <ddb/db_output.h>

#define NBREAKPOINTS    100
static struct db_breakpoint     db_break_table[NBREAKPOINTS];
static db_breakpoint_t          db_next_free_breakpoint = &db_break_table[0];
static db_breakpoint_t          db_free_breakpoints = 0;
static db_breakpoint_t          db_breakpoint_list = 0;

static db_breakpoint_t  db_breakpoint_alloc(void);
static void             db_breakpoint_free(db_breakpoint_t);
static void             db_delete_breakpoint(struct vm_map *, db_addr_t);
static db_breakpoint_t  db_find_breakpoint(struct vm_map *, db_addr_t);
static void             db_list_breakpoints(void);
static void             db_set_breakpoint(struct vm_map *, db_addr_t, int);

static db_breakpoint_t
db_breakpoint_alloc(void)
{
        db_breakpoint_t bkpt;

        if ((bkpt = db_free_breakpoints) != 0) {
                db_free_breakpoints = bkpt->link;
                return (bkpt);
        }
        if (db_next_free_breakpoint == &db_break_table[NBREAKPOINTS]) {
                db_printf("All breakpoints used.\n");
                return (0);
        }
        bkpt = db_next_free_breakpoint;
        db_next_free_breakpoint++;

        return (bkpt);
}

static void
db_breakpoint_free(db_breakpoint_t bkpt)
{
        bkpt->link = db_free_breakpoints;
        db_free_breakpoints = bkpt;
}

void
db_set_breakpoint(struct vm_map *map, db_addr_t addr, int count)
{
        db_breakpoint_t bkpt;

        if (db_find_breakpoint(map, addr)) {
                db_printf("Already set.\n");
                return;
        }

        bkpt = db_breakpoint_alloc();
        if (bkpt == 0) {
                db_printf("Too many breakpoints.\n");
                return;
        }

        bkpt->map = map;
        bkpt->address = BKPT_ADDR(addr);
        bkpt->flags = 0;
        bkpt->init_count = count;
        bkpt->count = count;

        bkpt->link = db_breakpoint_list;
        db_breakpoint_list = bkpt;
}

static void
db_delete_breakpoint(struct vm_map *map, db_addr_t addr)
{
        db_breakpoint_t bkpt;
        db_breakpoint_t *prev;

        for (prev = &db_breakpoint_list;
             (bkpt = *prev) != 0;
             prev = &bkpt->link) {
                if (db_map_equal(bkpt->map, map) &&
                    (bkpt->address == BKPT_ADDR(addr))) {
                        *prev = bkpt->link;
                        break;
                }
        }
        if (bkpt == 0) {
                db_printf("Not set.\n");
                return;
        }

        db_breakpoint_free(bkpt);
}

db_breakpoint_t
db_find_breakpoint(struct vm_map *map, db_addr_t addr)
{
        db_breakpoint_t bkpt;

        for (bkpt = db_breakpoint_list;
             bkpt != 0;
             bkpt = bkpt->link)
                if (db_map_equal(bkpt->map, map) &&
                    (bkpt->address == BKPT_ADDR(addr)))
                        return (bkpt);

        return (0);
}

db_breakpoint_t
db_find_breakpoint_here(db_addr_t addr)
{
        return db_find_breakpoint(db_map_addr(addr), addr);
}

static bool db_breakpoints_inserted = true;

void
db_set_breakpoints(void)
{
        db_breakpoint_t bkpt;

        if (!db_breakpoints_inserted) {

                for (bkpt = db_breakpoint_list;
                     bkpt != 0;
                     bkpt = bkpt->link)
                        if (db_map_current(bkpt->map)) {
                                bkpt->bkpt_inst = db_get_value(bkpt->address,
                                    BKPT_SIZE, false);
                                db_put_value(bkpt->address,
                                    BKPT_SIZE,
                                    BKPT_SET(bkpt->bkpt_inst, bkpt->address));
                        }
                db_breakpoints_inserted = true;
        }
}

void
db_clear_breakpoints(void)
{
        db_breakpoint_t bkpt;

        if (db_breakpoints_inserted) {

                for (bkpt = db_breakpoint_list;
                     bkpt != 0;
                     bkpt = bkpt->link)
                        if (db_map_current(bkpt->map))
                            db_put_value(bkpt->address, BKPT_SIZE,
                                bkpt->bkpt_inst);
                db_breakpoints_inserted = false;
        }
}

/*
 * List breakpoints.
 */
void
db_list_breakpoints(void)
{
        db_breakpoint_t bkpt;

        if (db_breakpoint_list == 0) {
                db_printf("No breakpoints set\n");
                return;
        }

        db_printf(" Map      Count    Address\n");
        for (bkpt = db_breakpoint_list;
             bkpt != 0;
             bkpt = bkpt->link) {
                db_printf("%s%p %5d    ",
                    db_map_current(bkpt->map) ? "*" : " ",
                    bkpt->map, bkpt->init_count);
                db_printsym(bkpt->address, DB_STGY_PROC, db_printf);
                db_printf("\n");
        }
}

/* Delete breakpoint */
/*ARGSUSED*/
void
db_delete_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
    const char *modif)
{

        db_delete_breakpoint(db_map_addr(addr), (db_addr_t)addr);
}

/* Set breakpoint with skip count */
/*ARGSUSED*/
void
db_breakpoint_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
    const char *modif)
{

        if (count == -1)
                count = 1;

        db_set_breakpoint(db_map_addr(addr), (db_addr_t)addr, count);
}

/* list breakpoints */
/*ARGSUSED*/
void
db_listbreak_cmd(db_expr_t addr, bool have_addr,
    db_expr_t count, const char *modif)
{

        db_list_breakpoints();
}

#include <uvm/uvm_extern.h>

/*
 *      We want ddb to be usable before most of the kernel has been
 *      initialized.  In particular, current_thread() or kernel_map
 *      (or both) may be null.
 */

bool
db_map_equal(struct vm_map *map1, struct vm_map *map2)
{

        return ((map1 == map2) ||
                ((map1 == NULL) && (map2 == kernel_map)) ||
                ((map1 == kernel_map) && (map2 == NULL)));
}

bool
db_map_current(struct vm_map *map)
{
#if 0
        thread_t        thread;

        return ((map == NULL) ||
                (map == kernel_map) ||
                (((thread = current_thread()) != NULL) &&
                 (map == thread->task->map)));
#else

        return (1);
#endif
}

struct vm_map *
db_map_addr(vaddr_t addr)
{
#if 0
        thread_t        thread;

        /*
         *      We want to return kernel_map for all
         *      non-user addresses, even when debugging
         *      kernel tasks with their own maps.
         */

        if ((VM_MIN_ADDRESS <= addr) && (addr < VM_MAX_ADDRESS) &&
            ((thread = current_thread()) != NULL))
                return thread->task->map;
        else
#endif
                return kernel_map;
}