[apple/xnu.git] / osfmk / ddb / db_break.c

/*
 * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/*
 * @OSF_COPYRIGHT@
 */
/*
 */
/*
 *      Author: David B. Golub, Carnegie Mellon University
 *      Date:   7/90
 */

/*
 * Breakpoints.
 */
#include <mach/boolean.h>
#include <machine/db_machdep.h>
#include <ddb/db_lex.h>
#include <ddb/db_break.h>
#include <ddb/db_access.h>
#include <ddb/db_sym.h>
#include <ddb/db_variables.h>
#include <ddb/db_command.h>
#include <ddb/db_cond.h>
#include <ddb/db_expr.h>
#include <ddb/db_output.h>              /* For db_printf() */
#include <ddb/db_task_thread.h>


#define NBREAKPOINTS    100
#define NTHREAD_LIST    (NBREAKPOINTS*3)

struct db_breakpoint    db_break_table[NBREAKPOINTS];
db_breakpoint_t         db_next_free_breakpoint = &db_break_table[0];
db_breakpoint_t         db_free_breakpoints = 0;
db_breakpoint_t         db_breakpoint_list = 0;

static struct db_thread_breakpoint      db_thread_break_list[NTHREAD_LIST];
static db_thread_breakpoint_t           db_free_thread_break_list = 0;
static boolean_t                        db_thread_break_init = FALSE;
static int                              db_breakpoint_number = 0;

/* Prototypes for functions local to this file.  XXX -- should be static!
 */
static int db_add_thread_breakpoint(
        register db_breakpoint_t        bkpt,
        vm_offset_t                     task_thd,
        int                             count,
        boolean_t                       task_bpt);

static int db_delete_thread_breakpoint(
        register db_breakpoint_t        bkpt,
        vm_offset_t                     task_thd);

static db_thread_breakpoint_t db_find_thread_breakpoint(
        db_breakpoint_t bkpt,
        thread_t        thr_act);

static void db_force_delete_breakpoint(
        db_breakpoint_t bkpt,
        vm_offset_t     task_thd,
        boolean_t       is_task);

db_breakpoint_t db_breakpoint_alloc(void);

void db_breakpoint_free(register db_breakpoint_t bkpt);

void db_delete_breakpoint(
        task_t          task,
        db_addr_t       addr,
        vm_offset_t     task_thd);

void
db_delete_all_breakpoints(
        task_t          task);

void db_list_breakpoints(void);



db_breakpoint_t
db_breakpoint_alloc(void)
{
        register 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);
}

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

static int
db_add_thread_breakpoint(
        register db_breakpoint_t        bkpt,
        vm_offset_t                     task_thd,
        int                             count,
        boolean_t                       task_bpt)
{
        register db_thread_breakpoint_t tp;

        if (db_thread_break_init == FALSE) {
            for (tp = db_thread_break_list; 
                tp < &db_thread_break_list[NTHREAD_LIST-1]; tp++)
                tp->tb_next = tp+1;
            tp->tb_next = 0;
            db_free_thread_break_list = db_thread_break_list;
            db_thread_break_init = TRUE;
        }
        if (db_free_thread_break_list == 0)
            return (-1);
        tp = db_free_thread_break_list;
        db_free_thread_break_list = tp->tb_next;
        tp->tb_is_task = task_bpt;
        tp->tb_task_thd = task_thd;
        tp->tb_count = count;
        tp->tb_init_count = count;
        tp->tb_cond = 0;
        tp->tb_number = ++db_breakpoint_number;
        tp->tb_next = bkpt->threads;
        bkpt->threads = tp;
        return(0);
}

static int
db_delete_thread_breakpoint(
        register db_breakpoint_t        bkpt,
        vm_offset_t                     task_thd)
{
        register db_thread_breakpoint_t tp;
        register db_thread_breakpoint_t *tpp;

        if (task_thd == 0) {
            /* delete all the thread-breakpoints */

            for (tpp = &bkpt->threads; (tp = *tpp) != 0; tpp = &tp->tb_next)
                db_cond_free(tp);

            *tpp = db_free_thread_break_list;
            db_free_thread_break_list = bkpt->threads;
            bkpt->threads = 0;
            return 0;
        } else {
            /* delete the specified thread-breakpoint */

            for (tpp = &bkpt->threads; (tp = *tpp) != 0; tpp = &tp->tb_next)
                if (tp->tb_task_thd == task_thd) {
                    db_cond_free(tp);
                    *tpp = tp->tb_next;
                    tp->tb_next = db_free_thread_break_list;
                    db_free_thread_break_list = tp;
                    return 0;
                }

            return -1;  /* not found */
        }
}

static db_thread_breakpoint_t
db_find_thread_breakpoint(
        db_breakpoint_t bkpt,
        thread_t        thr_act)
{
        register db_thread_breakpoint_t tp;
        register task_t task =
                        (thr_act == THREAD_NULL)
                                        ? TASK_NULL : thr_act->task;

        for (tp = bkpt->threads; tp; tp = tp->tb_next) {
            if (tp->tb_is_task) {
                if (tp->tb_task_thd == (vm_offset_t)task)
                    break;
                continue;
            }
            if (tp->tb_task_thd == (vm_offset_t)thr_act || tp->tb_task_thd == 0)
                break;
        }
        return(tp);
}

db_thread_breakpoint_t
db_find_thread_breakpoint_here(
        task_t          task,
        db_addr_t       addr)
{
        db_breakpoint_t bkpt;

        bkpt = db_find_breakpoint(task, (db_addr_t)addr);
        if (bkpt == 0)
            return(0);
        return(db_find_thread_breakpoint(bkpt, current_act()));
}

db_thread_breakpoint_t
db_find_breakpoint_number(
        int             num,
        db_breakpoint_t *bkptp)
{
        register db_thread_breakpoint_t tp;
        register db_breakpoint_t bkpt;

        for (bkpt = db_breakpoint_list; bkpt != 0; bkpt = bkpt->link) {
            for (tp = bkpt->threads; tp; tp = tp->tb_next) {
                if (tp->tb_number == num) {
                    if (bkptp)
                        *bkptp = bkpt;
                    return(tp);
                }
            }
        }
        return(0);
}

static void
db_force_delete_breakpoint(
        db_breakpoint_t bkpt,
        vm_offset_t     task_thd,
        boolean_t       is_task)
{
        db_printf("deleted a stale breakpoint at ");
        if (bkpt->task == TASK_NULL || db_lookup_task(bkpt->task) >= 0)
           db_task_printsym(bkpt->address, DB_STGY_PROC, bkpt->task);
        else
           db_printf("%#X", bkpt->address);
        if (bkpt->task)
           db_printf(" in task %X", bkpt->task);
        if (task_thd)
           db_printf(" for %s %X", (is_task)? "task": "thr_act", task_thd);
        db_printf("\n");
        db_delete_thread_breakpoint(bkpt, task_thd);
}

void
db_check_breakpoint_valid(void)
{
        register db_thread_breakpoint_t tbp, tbp_next;
        register db_breakpoint_t bkpt, *bkptp;

        bkptp = &db_breakpoint_list;
        for (bkpt = *bkptp; bkpt; bkpt = *bkptp) {
            if (bkpt->task != TASK_NULL) {
                if (db_lookup_task(bkpt->task) < 0) {
                    db_force_delete_breakpoint(bkpt, 0, FALSE);
                    *bkptp = bkpt->link;
                    db_breakpoint_free(bkpt);
                    continue;
                }
            } else {
                for (tbp = bkpt->threads; tbp; tbp = tbp_next) {
                    tbp_next = tbp->tb_next;
                    if (tbp->tb_task_thd == 0)
                        continue;
                    if ((tbp->tb_is_task && 
                         db_lookup_task((task_t)(tbp->tb_task_thd)) < 0) ||
                        (!tbp->tb_is_task && 
                         db_lookup_act((thread_t)(tbp->tb_task_thd)) < 0)) {
                        db_force_delete_breakpoint(bkpt, 
                                        tbp->tb_task_thd, tbp->tb_is_task);
                    }
                }
                if (bkpt->threads == 0) {
                    db_put_task_value(bkpt->address, BKPT_SIZE,
                                 bkpt->bkpt_inst, bkpt->task);
                    *bkptp = bkpt->link;
                    db_breakpoint_free(bkpt);
                    continue;
                }
            }
            bkptp = &bkpt->link;
        }
}

void
db_set_breakpoint(
        task_t          task,
        db_addr_t       addr,
        int             count,
        thread_t        thr_act,
        boolean_t       task_bpt)
{
        register db_breakpoint_t bkpt;
        db_breakpoint_t alloc_bkpt = 0;
        vm_offset_t task_thd;

        bkpt = db_find_breakpoint(task, addr);
        if (bkpt) {
            if (thr_act == THREAD_NULL
                || db_find_thread_breakpoint(bkpt, thr_act)) {
                db_printf("Already set.\n");
                return;
            }
        } else {
            if (!DB_CHECK_ACCESS(addr, BKPT_SIZE, task)) {
                if (task) {
                    db_printf("Warning: non-resident page for breakpoint at %llX",
                              (unsigned long long)addr);
                    db_printf(" in task %lX.\n", task);
                } else {
                    db_printf("Cannot set breakpoint at %llX in kernel space.\n",
                              (unsigned long long)addr);
                    return;
                }
            }
            alloc_bkpt = bkpt = db_breakpoint_alloc();
            if (bkpt == 0) {
                db_printf("Too many breakpoints.\n");
                return;
            }
            bkpt->task = task;
            bkpt->flags = (task && thr_act == THREAD_NULL)?
                                (BKPT_USR_GLOBAL|BKPT_1ST_SET): 0;
            bkpt->address = addr;
            bkpt->threads = 0;
        }
        if (db_breakpoint_list == 0)
            db_breakpoint_number = 0;
        task_thd = (task_bpt)   ? (vm_offset_t)(thr_act->task)
                                : (vm_offset_t)thr_act;
        if (db_add_thread_breakpoint(bkpt, task_thd, count, task_bpt) < 0) {
            if (alloc_bkpt)
                db_breakpoint_free(alloc_bkpt);
            db_printf("Too many thread_breakpoints.\n");
        } else {
            db_printf("set breakpoint #%x\n", db_breakpoint_number);
            if (alloc_bkpt) {
                bkpt->link = db_breakpoint_list;
                db_breakpoint_list = bkpt;
            }
        }
}

void
db_delete_breakpoint(
        task_t          task,
        db_addr_t       addr,
        vm_offset_t     task_thd)
{
        register db_breakpoint_t        bkpt;
        register db_breakpoint_t        *prev;

        for (prev = &db_breakpoint_list; (bkpt = *prev) != 0;
                                             prev = &bkpt->link) {
            if ((bkpt->task == task
                   || (task != TASK_NULL && (bkpt->flags & BKPT_USR_GLOBAL)))
                && bkpt->address == addr)
                break;
        }
        if (bkpt && (bkpt->flags & BKPT_SET_IN_MEM)) {
            db_printf("cannot delete it now.\n");
            return;
        }
        if (bkpt == 0
            || db_delete_thread_breakpoint(bkpt, task_thd) < 0) {
            db_printf("Not set.\n");
            return;
        }
        if (bkpt->threads == 0) {
            *prev = bkpt->link;
            db_breakpoint_free(bkpt);
        }
}

db_breakpoint_t
db_find_breakpoint(
        task_t          task,
        db_addr_t       addr)
{
        register db_breakpoint_t        bkpt;

        for (bkpt = db_breakpoint_list; bkpt != 0; bkpt = bkpt->link) {
            if ((bkpt->task == task
                  || (task != TASK_NULL && (bkpt->flags & BKPT_USR_GLOBAL)))
                && bkpt->address == addr)
                return (bkpt);
        }
        return (0);
}

boolean_t
db_find_breakpoint_here(
        task_t          task,
        db_addr_t       addr)
{
        register db_breakpoint_t        bkpt;

        for (bkpt = db_breakpoint_list; bkpt != 0; bkpt = bkpt->link) {
            if ((bkpt->task == task
                   || (task != TASK_NULL && (bkpt->flags & BKPT_USR_GLOBAL)))
                && bkpt->address == addr)
                return(TRUE);
            if ((bkpt->flags & BKPT_USR_GLOBAL) == 0 &&
                  DB_PHYS_EQ(task, addr, bkpt->task, bkpt->address))
                return (TRUE);
        }
        return(FALSE);
}

boolean_t       db_breakpoints_inserted = TRUE;

void
db_set_breakpoints(void)
{
        register db_breakpoint_t bkpt;
        register task_t task;
        db_expr_t       inst;
        thread_t        cur_act = current_act();
        task_t          cur_task =
                                (cur_act) ?
                                        cur_act->task : TASK_NULL;
        boolean_t       inserted = TRUE;

        if (!db_breakpoints_inserted) {
            for (bkpt = db_breakpoint_list; bkpt != 0; bkpt = bkpt->link) {
                if (bkpt->flags & BKPT_SET_IN_MEM)
                    continue;
                task = bkpt->task;
                if (bkpt->flags & BKPT_USR_GLOBAL) {
                    if ((bkpt->flags & BKPT_1ST_SET) == 0) {
                        if (cur_task == TASK_NULL)
                            continue;
                        task = cur_task;
                    } else
                        bkpt->flags &= ~BKPT_1ST_SET;
                }
                if (DB_CHECK_ACCESS(bkpt->address, BKPT_SIZE, task)) {
                    inst = db_get_task_value(bkpt->address, BKPT_SIZE, FALSE,
                                                                task);
                    if (inst == BKPT_SET(inst))
                        continue;
                    bkpt->bkpt_inst = inst;
                    db_put_task_value(bkpt->address,
                                BKPT_SIZE,
                                BKPT_SET(bkpt->bkpt_inst), task);
                    bkpt->flags |= BKPT_SET_IN_MEM;
                } else {
                    inserted = FALSE;
                }
            }
            db_breakpoints_inserted = inserted;
        }
}

void
db_clear_breakpoints(void)
{
        register db_breakpoint_t bkpt, *bkptp;
        register task_t  task;
        db_expr_t inst;
        thread_t         cur_act = current_act();
        task_t   cur_task = (cur_act) ?
                        cur_act->task: TASK_NULL;

        if (db_breakpoints_inserted) {
            bkptp = &db_breakpoint_list;
            for (bkpt = *bkptp; bkpt; bkpt = *bkptp) {
                task = bkpt->task;
                if (bkpt->flags & BKPT_USR_GLOBAL) {
                    if (cur_task == TASK_NULL) {
                        bkptp = &bkpt->link;
                        continue;
                    }
                    task = cur_task;
                }
                if ((bkpt->flags & BKPT_SET_IN_MEM)
                    && DB_CHECK_ACCESS(bkpt->address, BKPT_SIZE, task)) {
                    inst = db_get_task_value(bkpt->address, BKPT_SIZE, FALSE, 
                                                                task);
                    if (inst != BKPT_SET(inst)) {
                        if (bkpt->flags & BKPT_USR_GLOBAL) {
                            bkptp = &bkpt->link;
                            continue;
                        }
                        db_force_delete_breakpoint(bkpt, 0, FALSE);
                        *bkptp = bkpt->link;
                        db_breakpoint_free(bkpt);
                        continue;
                    }
                    db_put_task_value(bkpt->address, BKPT_SIZE,
                                 bkpt->bkpt_inst, task);
                    bkpt->flags &= ~BKPT_SET_IN_MEM;
                }
                bkptp = &bkpt->link;
            }
            db_breakpoints_inserted = FALSE;
        }
}

/*
 * Set a temporary breakpoint.
 * The instruction is changed immediately,
 * so the breakpoint does not have to be on the breakpoint list.
 */
db_breakpoint_t
db_set_temp_breakpoint(
        task_t          task,
        db_addr_t       addr)
{
        register db_breakpoint_t        bkpt;

        bkpt = db_breakpoint_alloc();
        if (bkpt == 0) {
            db_printf("Too many breakpoints.\n");
            return 0;
        }
        bkpt->task = task;
        bkpt->address = addr;
        bkpt->flags = BKPT_TEMP;
        bkpt->threads = 0;
        if (db_add_thread_breakpoint(bkpt, 0, 1, FALSE) < 0) {
            if (bkpt)
                db_breakpoint_free(bkpt);
            db_printf("Too many thread_breakpoints.\n");
            return 0;
        }
        bkpt->bkpt_inst = db_get_task_value(bkpt->address, BKPT_SIZE, 
                                                FALSE, task);
        db_put_task_value(bkpt->address, BKPT_SIZE, 
                                BKPT_SET(bkpt->bkpt_inst), task);
        return bkpt;
}

void
db_delete_temp_breakpoint(
        task_t          task,
        db_breakpoint_t bkpt)
{
        db_put_task_value(bkpt->address, BKPT_SIZE, bkpt->bkpt_inst, task);
        db_delete_thread_breakpoint(bkpt, 0);
        db_breakpoint_free(bkpt);
}

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

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

        db_printf(" No  Space    Task.Act    Cnt  Address(Cond)\n");
        for (bkpt = db_breakpoint_list;
             bkpt != 0;
             bkpt = bkpt->link)
        {
            register    db_thread_breakpoint_t tp;
            int         task_id;
            int         act_id;

            if (bkpt->threads) {
                for (tp = bkpt->threads; tp; tp = tp->tb_next) {
                    db_printf("%3d  ", tp->tb_number);
                    if (bkpt->flags & BKPT_USR_GLOBAL)
                        db_printf("user     ");
                    else if (bkpt->task == TASK_NULL)
                        db_printf("kernel   ");
                    else if ((task_id = db_lookup_task(bkpt->task)) < 0)
                        db_printf("%0*X ", 2*sizeof(vm_offset_t), bkpt->task);
                    else
                        db_printf("task%-3d  ", task_id);
                    if (tp->tb_task_thd == 0) {
                        db_printf("all         ");
                    } else {
                        if (tp->tb_is_task) {
                            task_id = db_lookup_task((task_t)(tp->tb_task_thd));
                            if (task_id < 0)
                                db_printf("%0*X    ", 2*sizeof(vm_offset_t),
                                           tp->tb_task_thd);
                            else
                                db_printf("task%03d     ", task_id);
                        } else {
                            thread_t thd = (thread_t)(tp->tb_task_thd);
                            task_id = db_lookup_task(thd->task);
                            act_id = db_lookup_task_act(thd->task, thd);
                            if (task_id < 0 || act_id < 0)
                                db_printf("%0*X    ", 2*sizeof(vm_offset_t),
                                                tp->tb_task_thd);
                            else        
                                db_printf("task%03d.%-3d ", task_id, act_id);
                        }
                    }
                    db_printf("%3d  ", tp->tb_init_count);
                    db_task_printsym(bkpt->address, DB_STGY_PROC, bkpt->task);
                    if (tp->tb_cond > 0) {
                        db_printf("(");
                        db_cond_print(tp);
                        db_printf(")");
                    }
                    db_printf("\n");
                }
            } else {
                if (bkpt->task == TASK_NULL)
                    db_printf("  ?  kernel   ");
                else
                    db_printf("%*X ", 2*sizeof(vm_offset_t), bkpt->task);
                db_printf("(?)              ");
                db_task_printsym(bkpt->address, DB_STGY_PROC, bkpt->task);
                db_printf("\n");
            }
        }
}

void
db_delete_all_breakpoints(
        task_t          task)
{
        register db_breakpoint_t        bkpt;

        bkpt = db_breakpoint_list;
        while ( bkpt != 0 ) {
                if (bkpt->task == task ||
                    (task != TASK_NULL && (bkpt->flags & BKPT_USR_GLOBAL))) {
                        db_delete_breakpoint(task, bkpt->address, 0);
                        bkpt = db_breakpoint_list;
                }
                else
                        bkpt = bkpt->link;
        
        }
}

/* Delete breakpoint */
void
db_delete_cmd(void)
{
        register int n;
        thread_t         thr_act;
        vm_offset_t task_thd;
        boolean_t user_global = FALSE;
        boolean_t task_bpt = FALSE;
        boolean_t user_space = FALSE;
        boolean_t thd_bpt = FALSE;
        db_expr_t addr;
        int t;
        
        t = db_read_token();
        if (t == tSLASH) {
            t = db_read_token();
            if (t != tIDENT) {
                db_printf("Bad modifier \"%s\"\n", db_tok_string);
                db_error(0);
            }
            user_global = db_option(db_tok_string, 'U');
            user_space = (user_global)? TRUE: db_option(db_tok_string, 'u');
            task_bpt = db_option(db_tok_string, 'T');
            thd_bpt = db_option(db_tok_string, 't');
            if (task_bpt && user_global)
                db_error("Cannot specify both 'T' and 'U' option\n");
            t = db_read_token();
        }

        if ( t == tSTAR ) {
                db_printf("Delete ALL breakpoints\n");
                db_delete_all_breakpoints( (task_t)task_bpt );
                return;
        }

        if (t == tHASH) {
            db_thread_breakpoint_t tbp;
            db_breakpoint_t bkpt;

            if (db_read_token() != tNUMBER) {
                db_printf("Bad break point number #%s\n", db_tok_string);
                db_error(0);
            }
            if ((tbp = db_find_breakpoint_number(db_tok_number, &bkpt)) == 0) {
                db_printf("No such break point #%d\n", db_tok_number);
                db_error(0);
            }
            db_delete_breakpoint(bkpt->task, bkpt->address, tbp->tb_task_thd);
            return;
        }
        db_unread_token(t);
        if (!db_expression(&addr)) {
            /*
             *  We attempt to pick up the user_space indication from db_dot,
             *  so that a plain "d" always works.
             */
            addr = (db_expr_t)db_dot;
            if (!user_space && !DB_VALID_ADDRESS(addr, FALSE))
                user_space = TRUE;
        }
        if (!DB_VALID_ADDRESS(addr, user_space)) {
            db_printf("Address %#llX is not in %s space\n", (unsigned long long)addr, 
                        (user_space)? "user": "kernel");
            db_error(0);
        }
        if (thd_bpt || task_bpt) {
            for (n = 0; db_get_next_act(&thr_act, n); n++) {
                if (thr_act == THREAD_NULL)
                    db_error("No active thr_act\n");
                if (task_bpt) {
                    if (thr_act->task == TASK_NULL)
                        db_error("No task\n");
                    task_thd = (vm_offset_t) (thr_act->task);
                } else
                    task_thd = (user_global)? 0: (vm_offset_t) thr_act;
                db_delete_breakpoint(db_target_space(thr_act, user_space),
                                        (db_addr_t)addr, task_thd);
            }
        } else {
            db_delete_breakpoint(db_target_space(THREAD_NULL, user_space),
                                         (db_addr_t)addr, 0);
        }
}

/* Set breakpoint with skip count */
#include <mach/machine/vm_param.h>

void
db_breakpoint_cmd(
        db_expr_t       addr,
        int             have_addr,
        db_expr_t       count,
        char *          modif)
{
        register int n;
        thread_t thr_act;
        boolean_t user_global = db_option(modif, 'U');
        boolean_t task_bpt = db_option(modif, 'T');
        boolean_t user_space;

        if (count == -1)
            count = 1;
#if 0 /* CHECKME */
        if (!task_bpt && db_option(modif,'t'))
          task_bpt = TRUE;
#endif

        if (task_bpt && user_global)
            db_error("Cannot specify both 'T' and 'U'\n");
        user_space = (user_global)? TRUE: db_option(modif, 'u');
        if (user_space && db_access_level < DB_ACCESS_CURRENT)
            db_error("User space break point is not supported\n");
        if ((!task_bpt || !user_space) &&
            !DB_VALID_ADDRESS(addr, user_space)) {
            /* if the user has explicitly specified user space,
               do not insert a breakpoint into the kernel */
            if (user_space)
              db_error("Invalid user space address\n");
            user_space = TRUE;
            db_printf("%#llX is in user space\n", (unsigned long long)addr);
#ifdef ppc
            db_printf("kernel is from %#X to %#x\n", VM_MIN_KERNEL_ADDRESS, vm_last_addr);
#else
            db_printf("kernel is from %#X to %#x\n", VM_MIN_KERNEL_ADDRESS, VM_MAX_KERNEL_ADDRESS);
#endif
        }
        if (db_option(modif, 't') || task_bpt) {
            for (n = 0; db_get_next_act(&thr_act, n); n++) {
                if (thr_act == THREAD_NULL)
                    db_error("No active thr_act\n");
                if (task_bpt && thr_act->task == TASK_NULL)
                    db_error("No task\n");
                if (db_access_level <= DB_ACCESS_CURRENT && user_space
                         && thr_act->task != db_current_space())
                    db_error("Cannot set break point in inactive user space\n");
                db_set_breakpoint(db_target_space(thr_act, user_space), 
                                        (db_addr_t)addr, count,
                                        (user_global)? THREAD_NULL: thr_act,
                                        task_bpt);
            }
        } else {
            db_set_breakpoint(db_target_space(THREAD_NULL, user_space),
                                 (db_addr_t)addr,
                                 count, THREAD_NULL, FALSE);
        }
}

/* list breakpoints */
void
db_listbreak_cmd(void)
{
        db_list_breakpoints();
}