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[netbsd-mini2440.git] / sys / ddb / db_command.c

/*      $NetBSD: db_command.c,v 1.132 2009/06/05 04:31:47 mrg Exp $     */

/*
 * Copyright (c) 1996, 1997, 1998, 1999, 2002, 2009 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Adam Hamsik, and by Andrew Doran.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * 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.
 */

/*
 * Command dispatcher.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: db_command.c,v 1.132 2009/06/05 04:31:47 mrg Exp $");

#ifdef _KERNEL_OPT
#include "opt_aio.h"
#include "opt_ddb.h"
#include "opt_kgdb.h"
#include "opt_mqueue.h"
#include "opt_inet.h"
#include "opt_uvmhist.h"
#include "opt_ddbparam.h"
#include "opt_multiprocessor.h"
#include "arp.h"
#endif

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/reboot.h>
#include <sys/device.h>
#include <sys/lwp.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/namei.h>
#include <sys/pool.h>
#include <sys/proc.h>
#include <sys/vnode.h>
#include <sys/vmem.h>
#include <sys/lockdebug.h>
#include <sys/cpu.h>
#include <sys/buf.h>
#include <sys/module.h>

/*include queue macros*/
#include <sys/queue.h>

#include <ddb/ddb.h>

#include <uvm/uvm_extern.h>
#include <uvm/uvm_ddb.h>

/*
 * Results of command search.
 */
#define CMD_EXACT               0
#define CMD_PREFIX              1
#define CMD_NONE                2
#define CMD_AMBIGUOUS   3

/*
 * Exported global variables
 */
bool            db_cmd_loop_done;
label_t         *db_recover;
db_addr_t       db_dot;
db_addr_t       db_last_addr;
db_addr_t       db_prev;
db_addr_t       db_next;


/*
 * New DDB api for adding and removing commands uses three lists, because
 * we use two types of commands
 * a) standard commands without subcommands -> reboot
 * b) show commands which are subcommands of show command -> show aio_jobs
 * c) if defined machine specific commands
 *
 * ddb_add_cmd, ddb_rem_cmd use type (DDB_SHOW_CMD||DDB_BASE_CMD)argument to
 * add them to representativ lists.
 */

static const struct db_command db_command_table[];
static const struct db_command db_show_cmds[];

#ifdef DB_MACHINE_COMMANDS
static const struct db_command db_machine_command_table[];
#endif

/* the global queue of all command tables */
TAILQ_HEAD(db_cmd_tbl_en_head, db_cmd_tbl_en);

/* TAILQ entry used to register command tables */
struct db_cmd_tbl_en {
        const struct db_command *db_cmd;        /* cmd table */
        TAILQ_ENTRY(db_cmd_tbl_en) db_cmd_next;
};

/* head of base commands list */
static struct db_cmd_tbl_en_head db_base_cmd_list =
        TAILQ_HEAD_INITIALIZER(db_base_cmd_list);
static struct db_cmd_tbl_en db_base_cmd_builtins =
     { .db_cmd = db_command_table };

/* head of show commands list */
static struct db_cmd_tbl_en_head db_show_cmd_list =
        TAILQ_HEAD_INITIALIZER(db_show_cmd_list);
static struct db_cmd_tbl_en db_show_cmd_builtins =
     { .db_cmd = db_show_cmds };

/* head of machine commands list */
static struct db_cmd_tbl_en_head db_mach_cmd_list =
        TAILQ_HEAD_INITIALIZER(db_mach_cmd_list);
#ifdef DB_MACHINE_COMMANDS
static struct db_cmd_tbl_en db_mach_cmd_builtins =
     { .db_cmd = db_machine_command_table };
#endif

/*
 * if 'ed' style: 'dot' is set at start of last item printed,
 * and '+' points to next line.
 * Otherwise: 'dot' points to next item, '..' points to last.
 */
static bool      db_ed_style = true;

static void     db_init_commands(void);
static int      db_register_tbl_entry(uint8_t type,
    struct db_cmd_tbl_en *list_ent);
static void     db_cmd_list(const struct db_cmd_tbl_en_head *);
static int      db_cmd_search(const char *, struct db_cmd_tbl_en_head *,
                              const struct db_command **);
static int      db_cmd_search_table(const char *, const struct db_command *,
                                    const struct db_command **);
static void     db_cmd_search_failed(char *, int);
static const struct db_command *db_read_command(void);
static void     db_command(const struct db_command **);
static void     db_buf_print_cmd(db_expr_t, bool, db_expr_t, const char *);
static void     db_event_print_cmd(db_expr_t, bool, db_expr_t, const char *);
static void     db_fncall(db_expr_t, bool, db_expr_t, const char *);
static void     db_help_print_cmd(db_expr_t, bool, db_expr_t, const char *);
static void     db_lock_print_cmd(db_expr_t, bool, db_expr_t, const char *);
static void     db_mount_print_cmd(db_expr_t, bool, db_expr_t, const char *);
static void     db_mbuf_print_cmd(db_expr_t, bool, db_expr_t, const char *);
static void     db_malloc_print_cmd(db_expr_t, bool, db_expr_t, const char *);
static void     db_map_print_cmd(db_expr_t, bool, db_expr_t, const char *);
static void     db_namecache_print_cmd(db_expr_t, bool, db_expr_t,
                    const char *);
static void     db_object_print_cmd(db_expr_t, bool, db_expr_t, const char *);
static void     db_page_print_cmd(db_expr_t, bool, db_expr_t, const char *);
static void     db_show_all_pages(db_expr_t, bool, db_expr_t, const char *);
static void     db_pool_print_cmd(db_expr_t, bool, db_expr_t, const char *);
static void     db_reboot_cmd(db_expr_t, bool, db_expr_t, const char *);
static void     db_sifting_cmd(db_expr_t, bool, db_expr_t, const char *);
static void     db_stack_trace_cmd(db_expr_t, bool, db_expr_t, const char *);
static void     db_sync_cmd(db_expr_t, bool, db_expr_t, const char *);
static void     db_whatis_cmd(db_expr_t, bool, db_expr_t, const char *);
static void     db_uvmexp_print_cmd(db_expr_t, bool, db_expr_t, const char *);
#ifdef UVMHIST
static void     db_uvmhist_print_cmd(db_expr_t, bool, db_expr_t, const char *);
#endif
static void     db_vnode_print_cmd(db_expr_t, bool, db_expr_t, const char *);
static void     db_vmem_print_cmd(db_expr_t, bool, db_expr_t, const char *);

static const struct db_command db_show_cmds[] = {
        /*added from all sub cmds*/
#ifdef _KERNEL  /* XXX CRASH(8) */
        { DDB_ADD_CMD("callout",  db_show_callout,
            0 ,"List all used callout functions.",NULL,NULL) },
#endif
        { DDB_ADD_CMD("pages",  db_show_all_pages,
            0 ,"List all used memory pages.",NULL,NULL) },
        { DDB_ADD_CMD("procs",  db_show_all_procs,
            0 ,"List all processes.",NULL,NULL) },
        { DDB_ADD_CMD("pools",  db_show_all_pools,
            0 ,"Show all poolS",NULL,NULL) },
#ifdef AIO
        /*added from all sub cmds*/
        { DDB_ADD_CMD("aio_jobs",       db_show_aio_jobs,       0,
            "Show aio jobs",NULL,NULL) },
#endif
        { DDB_ADD_CMD("all",    NULL,
            CS_COMPAT, NULL,NULL,NULL) },
#if defined(INET) && (NARP > 0)
        { DDB_ADD_CMD("arptab", db_show_arptab,         0,NULL,NULL,NULL) },
#endif
#ifdef _KERNEL
        { DDB_ADD_CMD("breaks", db_listbreak_cmd,       0,
            "Display all breaks.",NULL,NULL) },
#endif
        { DDB_ADD_CMD("buf",    db_buf_print_cmd,       0,
            "Print the struct buf at address.", "[/f] address",NULL) },
        { DDB_ADD_CMD("event",  db_event_print_cmd,     0,
            "Print all the non-zero evcnt(9) event counters.", "[/fitm]",NULL) },
        { DDB_ADD_CMD("files", db_show_files_cmd,       0,
            "Print the files open by process at address",
            "[/f] address", NULL) },
        { DDB_ADD_CMD("lock",   db_lock_print_cmd,      0,NULL,NULL,NULL) },
        { DDB_ADD_CMD("malloc", db_malloc_print_cmd,0,NULL,NULL,NULL) },
        { DDB_ADD_CMD("map",    db_map_print_cmd,       0,
            "Print the vm_map at address.", "[/f] address",NULL) },
        { DDB_ADD_CMD("module", db_show_module_cmd,     0,
            "Print kernel modules", NULL, NULL) },
        { DDB_ADD_CMD("mount",  db_mount_print_cmd,     0,
            "Print the mount structure at address.", "[/f] address",NULL) },
#ifdef MQUEUE
        { DDB_ADD_CMD("mqueue", db_show_mqueue_cmd,     0,
            "Print the message queues", NULL, NULL) },
#endif
        { DDB_ADD_CMD("mbuf",   db_mbuf_print_cmd,      0,NULL,NULL,
            "-c prints all mbuf chains") },
        { DDB_ADD_CMD("ncache", db_namecache_print_cmd, 0,
            "Dump the namecache list.", "address",NULL) },
        { DDB_ADD_CMD("object", db_object_print_cmd,    0,
            "Print the vm_object at address.", "[/f] address",NULL) },
        { DDB_ADD_CMD("page",   db_page_print_cmd,      0,
            "Print the vm_page at address.", "[/f] address",NULL) },
        { DDB_ADD_CMD("pool",   db_pool_print_cmd,      0,
            "Print the pool at address.", "[/clp] address",NULL) },
        { DDB_ADD_CMD("registers",      db_show_regs,           0,
            "Display the register set.", "[/u]",NULL) },
        { DDB_ADD_CMD("sched_qs",       db_show_sched_qs,       0,
            "Print the state of the scheduler's run queues.",
            NULL,NULL) },
        { DDB_ADD_CMD("uvmexp", db_uvmexp_print_cmd, 0,
            "Print a selection of UVM counters and statistics.",
            NULL,NULL) },
#ifdef UVMHIST
        { DDB_ADD_CMD("uvmhist", db_uvmhist_print_cmd, 0,
            "Print the UVM history logs.",
            NULL,NULL) },
#endif
        { DDB_ADD_CMD("vnode",  db_vnode_print_cmd,     0,
            "Print the vnode at address.", "[/f] address",NULL) },
        { DDB_ADD_CMD("vmem", db_vmem_print_cmd,        0,
            "Print the vmem usage.", "[/a] address", NULL) },
        { DDB_ADD_CMD("vmems", db_show_all_vmems,       0,
            "Show all vmems.", NULL, NULL) },
#ifdef _KERNEL
        { DDB_ADD_CMD("watches",        db_listwatch_cmd,       0,
            "Display all watchpoints.", NULL,NULL) },
#endif
        { DDB_ADD_CMD(NULL,             NULL,                   0,NULL,NULL,NULL) }
};

/* arch/<arch>/<arch>/db_interface.c */
#ifdef DB_MACHINE_COMMANDS
extern const struct db_command db_machine_command_table[];
#endif

static const struct db_command db_command_table[] = {
        { DDB_ADD_CMD("b",              db_breakpoint_cmd,      0,
            "Set a breakpoint at address", "[/u] address[,count].",NULL) },
        { DDB_ADD_CMD("break",  db_breakpoint_cmd,      0,
            "Set a breakpoint at address", "[/u] address[,count].",NULL) },
        { DDB_ADD_CMD("bt",             db_stack_trace_cmd,     0,
            "Show backtrace.", "See help trace.",NULL) },
        { DDB_ADD_CMD("c",              db_continue_cmd,        0,
            "Continue execution.", "[/c]",NULL) },
        { DDB_ADD_CMD("call",   db_fncall,              CS_OWN,
            "Call the function", "address[(expression[,...])]",NULL) },
#ifdef _KERNEL  /* XXX CRASH(8) */
        { DDB_ADD_CMD("callout",        db_show_callout,        0, NULL,
            NULL,NULL ) },
#endif
        { DDB_ADD_CMD("continue",       db_continue_cmd,        0,
            "Continue execution.", "[/c]",NULL) },
        { DDB_ADD_CMD("d",              db_delete_cmd,          0,
            "Delete a breakpoint.", "address | #number",NULL) },
        { DDB_ADD_CMD("delete", db_delete_cmd,          0,
            "Delete a breakpoint.", "address | #number",NULL) },
        { DDB_ADD_CMD("dmesg",  db_dmesg,               0,
            "Show kernel message buffer.", "[count]",NULL) },
        { DDB_ADD_CMD("dwatch", db_deletewatch_cmd,     0,
            "Delete the watchpoint.", "address",NULL) },
        { DDB_ADD_CMD("examine",        db_examine_cmd,         CS_SET_DOT,
            "Display the address locations.",
            "[/modifier] address[,count]",NULL) },
        { DDB_ADD_CMD("exit",           db_continue_cmd,        0,
            "Continue execution.", "[/c]",NULL) },
        { DDB_ADD_CMD("help",   db_help_print_cmd, CS_OWN|CS_NOREPEAT,
            "Display help about commands",
            "Use other commands as arguments.",NULL) },
        { DDB_ADD_CMD("kill",   db_kill_proc,           CS_OWN,
            "Send a signal to the process","pid[,signal_number]",
            "   pid:\t\t\tthe process id (may need 0t prefix for decimal)\n"
            "   signal_number:\tthe signal to send") },
#ifdef KGDB
        { DDB_ADD_CMD("kgdb",   db_kgdb_cmd,    0,      NULL,NULL,NULL) },
#endif
        { DDB_ADD_CMD("machine",NULL,CS_MACH,
            "Architecture specific functions.",NULL,NULL) },
        { DDB_ADD_CMD("match",  db_trace_until_matching_cmd,0,
            "Stop at the matching return instruction.","See help next",NULL) },
        { DDB_ADD_CMD("next",   db_trace_until_matching_cmd,0,
            "Stop at the matching return instruction.","[/p]",NULL) },
        { DDB_ADD_CMD("p",              db_print_cmd,           0,
            "Print address according to the format.",
            "[/axzodurc] address [address ...]",NULL) },
        { DDB_ADD_CMD("print",  db_print_cmd,           0,
            "Print address according to the format.",
            "[/axzodurc] address [address ...]",NULL) },
        { DDB_ADD_CMD("ps",             db_show_all_procs,      0,
            "Print all processes.","See show all procs",NULL) },
        { DDB_ADD_CMD("quit",           db_continue_cmd,        0,
            "Continue execution.", "[/c]",NULL) },
        { DDB_ADD_CMD("reboot", db_reboot_cmd,          CS_OWN,
            "Reboot","0x1  RB_ASKNAME, 0x2 RB_SINGLE, 0x4 RB_NOSYNC, 0x8 RB_HALT,"
            "0x40 RB_KDB, 0x100 RB_DUMP, 0x808 RB_POWERDOWN",NULL) },
        { DDB_ADD_CMD("s",              db_single_step_cmd,     0,
            "Single-step count times.","[/p] [,count]",NULL) },
        { DDB_ADD_CMD("search", db_search_cmd,          CS_OWN|CS_SET_DOT,
            "Search memory from address for value.",
            "[/bhl] address value [mask] [,count]",NULL) },
        { DDB_ADD_CMD("set",    db_set_cmd,             CS_OWN,
            "Set the named variable","$variable [=] expression",NULL) },
        { DDB_ADD_CMD("show",   NULL, CS_SHOW,
            "Show kernel stats.", NULL,NULL) },
        { DDB_ADD_CMD("sifting",        db_sifting_cmd,         CS_OWN,
            "Search the symbol tables ","[/F] string",NULL) },
        { DDB_ADD_CMD("step",   db_single_step_cmd,     0,
            "Single-step count times.","[/p] [,count]",NULL) },
        { DDB_ADD_CMD("sync",   db_sync_cmd,            CS_OWN,
            "Force a crash dump, and then reboot.",NULL,NULL) },
        { DDB_ADD_CMD("trace",  db_stack_trace_cmd,     0,
            "Stack trace from frame-address.",
            "[/u[l]] [frame-address][,count]",NULL) },
        { DDB_ADD_CMD("until",  db_trace_until_call_cmd,0,
            "Stop at the next call or return instruction.","[/p]",NULL) },
        { DDB_ADD_CMD("w",              db_write_cmd,           CS_MORE|CS_SET_DOT,
            "Write the expressions at succeeding locations.",
            "[/bhl] address expression [expression ...]",NULL) },
        { DDB_ADD_CMD("watch",  db_watchpoint_cmd,      CS_MORE,
            "Set a watchpoint for a region. ","address[,size]",NULL) },
        { DDB_ADD_CMD("whatis", db_whatis_cmd, 0,
            "Describe what an address is", "address", NULL) },
        { DDB_ADD_CMD("write",  db_write_cmd,           CS_MORE|CS_SET_DOT,
            "Write the expressions at succeeding locations.",
            "[/bhl] address expression [expression ...]",NULL) },
        { DDB_ADD_CMD("x",              db_examine_cmd,         CS_SET_DOT,
            "Display the address locations.",
            "[/modifier] address[,count]",NULL) },
        { DDB_ADD_CMD(NULL,     NULL,              0, NULL, NULL, NULL) }
};

static const struct db_command  *db_last_command = NULL;
#if defined(DDB_COMMANDONENTER)
char db_cmd_on_enter[DB_LINE_MAXLEN + 1] = ___STRING(DDB_COMMANDONENTER);
#else /* defined(DDB_COMMANDONENTER) */
char db_cmd_on_enter[DB_LINE_MAXLEN + 1] = "";
#endif /* defined(DDB_COMMANDONENTER) */
#define DB_LINE_SEP     ';'

/*
 * Execute commandlist after ddb start
 * This function goes through the command list created from commands and ';'
 */
static void
db_execute_commandlist(const char *cmdlist)
{
        const char *cmd = cmdlist;
        const struct db_command *dummy = NULL;

        while (*cmd != '\0') {
                const char *ep = cmd;

                while (*ep != '\0' && *ep != DB_LINE_SEP) {
                        ep++;
                }
                db_set_line(cmd, ep);
                db_command(&dummy);
                cmd = ep;
                if (*cmd == DB_LINE_SEP) {
                        cmd++;
                }
        }
}

/* Initialize ddb command tables */
void
db_init_commands(void)
{
        static bool done = false;

        if (done) return;
        done = true;

        /* register command tables */
        (void)db_register_tbl_entry(DDB_BASE_CMD, &db_base_cmd_builtins);
#ifdef DB_MACHINE_COMMANDS
        (void)db_register_tbl_entry(DDB_MACH_CMD, &db_mach_cmd_builtins);
#endif
        (void)db_register_tbl_entry(DDB_SHOW_CMD, &db_show_cmd_builtins);
}


/*
 * Add command table to the specified list
 * Arg:
 * int type specifies type of command table DDB_SHOW_CMD|DDB_BASE_CMD|DDB_MAC_CMD
 * *cmd_tbl poiter to static allocated db_command table
 *
 * Command table must be NULL terminated array of struct db_command
 */
int
db_register_tbl(uint8_t type, const struct db_command *cmd_tbl)
{
        struct db_cmd_tbl_en *list_ent;
        
        /* empty list - ignore */
        if (cmd_tbl->name == 0)
                return 0;

        /* force builtin commands to be registered first */
        db_init_commands();

        /* now create a list entry for this table */
        list_ent = db_zalloc(sizeof(*list_ent));
        if (list_ent == NULL)
                return ENOMEM;
        list_ent->db_cmd=cmd_tbl;

        /* and register it */
        return db_register_tbl_entry(type, list_ent);
}

static int
db_register_tbl_entry(uint8_t type, struct db_cmd_tbl_en *list_ent)
{
        struct db_cmd_tbl_en_head *list;

        switch(type) {
        case DDB_BASE_CMD:
                list = &db_base_cmd_list;
                break;
        case DDB_SHOW_CMD:
                list = &db_show_cmd_list;
                break;
        case DDB_MACH_CMD:
                list = &db_mach_cmd_list;
                break;
        default:
                return ENOENT;
        }

        TAILQ_INSERT_TAIL(list, list_ent, db_cmd_next);

        return 0;
}

/*
 * Remove command table specified with db_cmd address == cmd_tbl
 */
int
db_unregister_tbl(uint8_t type,const struct db_command *cmd_tbl)
{
        struct db_cmd_tbl_en *list_ent;
        struct db_cmd_tbl_en_head *list;

        /* find list on which the entry should live */
        switch (type) {
        case DDB_BASE_CMD:
                list=&db_base_cmd_list;
                break;
        case DDB_SHOW_CMD:
                list=&db_show_cmd_list;
                break;
        case DDB_MACH_CMD:
                list=&db_mach_cmd_list;
                break;
        default:
                return EINVAL;
        }

        TAILQ_FOREACH (list_ent, list, db_cmd_next) {
                if (list_ent->db_cmd == cmd_tbl){
                        TAILQ_REMOVE(list,
                            list_ent, db_cmd_next);
                        db_free(list_ent, sizeof(*list_ent));
                        return 0;
                }
        }
        return ENOENT;
}

/* This function is called from machine trap code. */
void
db_command_loop(void)
{
        label_t db_jmpbuf;
        label_t *savejmp;

        /*
         * Initialize 'prev' and 'next' to dot.
         */
        db_prev = db_dot;
        db_next = db_dot;

        db_cmd_loop_done = false;

        /* Init default command tables add machine, base,
           show command tables to the list */
        db_init_commands();

        /* save context for return from ddb */
        savejmp = db_recover;
        db_recover = &db_jmpbuf;
        (void) setjmp(&db_jmpbuf);

        /* Execute default ddb start commands */
        db_execute_commandlist(db_cmd_on_enter);

        (void) setjmp(&db_jmpbuf);
        while (!db_cmd_loop_done) {
                if (db_print_position() != 0)
                        db_printf("\n");
                db_output_line = 0;
                (void) db_read_line();
                db_command(&db_last_command);
        }

        db_recover = savejmp;
}

/*
 * Search command table for command prefix
 */
static int
db_cmd_search_table(const char *name,
                    const struct db_command *table,
                    const struct db_command **cmdp)
{

        const struct db_command *cmd;
        int result;

        result = CMD_NONE;
        *cmdp = NULL;

        for (cmd = table; cmd->name != 0; cmd++) {
                const char *lp;
                const char *rp;

                lp = name;
                rp = cmd->name;
                while (*lp != '\0' && *lp == *rp) {
                        rp++;
                        lp++;
                }

                if (*lp != '\0') /* mismatch or extra chars in name */
                        continue;

                if (*rp == '\0') { /* exact match */
                        *cmdp = cmd;
                        return (CMD_EXACT);
                }

                /* prefix match: end of name, not end of command */
                if (result == CMD_NONE) {
                        result = CMD_PREFIX;
                        *cmdp = cmd;
                }
                else if (result == CMD_PREFIX) {
                        result = CMD_AMBIGUOUS;
                        *cmdp = NULL;
                }
        }

        return (result);
}


/*
 * Search list of command tables for command
 */
static int
db_cmd_search(const char *name,
              struct db_cmd_tbl_en_head *list_head,
              const struct db_command **cmdp)
{
        struct db_cmd_tbl_en *list_ent;
        const struct db_command *found_command;
        bool accept_prefix_match;
        int result;

        result = CMD_NONE;
        found_command = NULL;
        accept_prefix_match = true;

        TAILQ_FOREACH(list_ent, list_head, db_cmd_next) {
                const struct db_command *cmd;
                int found;

                found = db_cmd_search_table(name, list_ent->db_cmd, &cmd);
                if (found == CMD_EXACT) {
                        result = CMD_EXACT;
                        found_command = cmd;
                        break;
                }

                if (found == CMD_PREFIX) {
                        if (accept_prefix_match) {
                                /*
                                 * Continue search, but note current result
                                 * in case we won't find anything else.
                                 */
                                accept_prefix_match = false;
                                result = CMD_PREFIX;
                                found_command = cmd;
                        } else {
                                /*
                                 * Watch out for globally ambiguous
                                 * prefix match that is not locally
                                 * ambiguous - with one match in one
                                 * table and another match(es) in
                                 * another table.
                                 */
                                result = CMD_AMBIGUOUS;
                                found_command = NULL;
                        }
                }
                else if (found == CMD_AMBIGUOUS) {
                        accept_prefix_match = false;
                        result = CMD_AMBIGUOUS;
                        found_command = NULL;
                }
        }

        *cmdp = found_command;
        return result;
}

static void
db_cmd_search_failed(char *name, int search_result)
{
        if (search_result == CMD_NONE)
                db_printf("No such command: %s\n", name);
        else
                db_printf("Ambiguous command: %s\n", name);
}


/*
 * List commands to the console.
 */
static void
db_cmd_list(const struct db_cmd_tbl_en_head *list)
{

        struct db_cmd_tbl_en *list_ent;
        const struct db_command *table;
        size_t          i, j, w, columns, lines, numcmds, width=0;
        const char      *p;

        TAILQ_FOREACH(list_ent,list,db_cmd_next) {
                table = list_ent->db_cmd;
                for (i = 0; table[i].name != NULL; i++) {
                        w = strlen(table[i].name);
                        if (w > width)
                                width = w;
                }
        }

        width = DB_NEXT_TAB(width);

        columns = db_max_width / width;
        if (columns == 0)
                columns = 1;

        TAILQ_FOREACH(list_ent,list,db_cmd_next) {
                table = list_ent->db_cmd;

                for (numcmds = 0; table[numcmds].name != NULL; numcmds++)
                        ;
                lines = (numcmds + columns - 1) / columns;

                for (i = 0; i < lines; i++) {
                        for (j = 0; j < columns; j++) {
                                p = table[j * lines + i].name;
                                if (p)
                                        db_printf("%s", p);
                                if (j * lines + i + lines >= numcmds) {
                                        db_putchar('\n');
                                        break;
                                }
                                if (p) {
                                        w = strlen(p);
                                        while (w < width) {
                                                w = DB_NEXT_TAB(w);
                                                db_putchar('\t');
                                        }
                                }
                        }
                }
        }
        return;
}

/*
 * Read complete command with all subcommands, starting with current
 * db_tok_string. If subcommand is missing, print the list of all
 * subcommands.  If command/subcommand is not found, print an error
 * message.  Returns pointer to "leaf" command or NULL.
 */
static const struct db_command *
db_read_command(void)
{
        const struct db_command *command;
        struct db_cmd_tbl_en_head *list;
        int found;
        int t;

        list = &db_base_cmd_list;
        do {
                found = db_cmd_search(db_tok_string, list, &command);
                if (command == NULL) {
                        db_cmd_search_failed(db_tok_string, found);
                        db_flush_lex();
                        return NULL;
                }

                if (command->flag == CS_SHOW)
                        list = &db_show_cmd_list;
                else if (command->flag == CS_MACH)
                        list = &db_mach_cmd_list;
                else if (command->flag == CS_COMPAT)
                        /* same list */;
                else
                        break; /* expect no more subcommands */

                t = db_read_token(); /* read subcommand */
                if (t != tIDENT) {
                        /* if none given - just print all of them */
                        db_cmd_list(list);
                        db_flush_lex();
                        return NULL;
                }
        } while (list != NULL);

        return command;
}

/*
 * Parse command line and execute apropriate function.
 */
static void
db_command(const struct db_command **last_cmdp)
{
        const struct db_command *command;
        static db_expr_t last_count = 0;
        db_expr_t       addr, count;
        char            modif[TOK_STRING_SIZE];
        
        int                     t;
        bool            have_addr = false;

        command = NULL;
        
        t = db_read_token();
        if ((t == tEOL) || (t == tCOMMA)) {
                /*
                 * An empty line repeats last command, at 'next'.
                 * Only a count repeats the last command with the new count.
                 */
                command = *last_cmdp;

                if (!command)
                        return;

                addr = (db_expr_t)db_next;
                if (t == tCOMMA) {
                        if (!db_expression(&count)) {
                                db_printf("Count missing\n");
                                db_flush_lex();
                                return;
                        }
                } else
                        count = last_count;
                have_addr = false;
                modif[0] = '\0';
                db_skip_to_eol();

        } else if (t == tEXCL) {
                db_fncall(0, 0, 0, NULL);
                return;

        } else if (t != tIDENT) {
                db_printf("?\n");
                db_flush_lex();
                return;

        } else {

                command = db_read_command();
                if (command == NULL)
                        return;

                if ((command->flag & CS_OWN) == 0) {

                        /*
                         * Standard syntax:
                         * command [/modifier] [addr] [,count]
                         */
                        t = db_read_token(); /* get modifier */
                        if (t == tSLASH) {
                                t = db_read_token();
                                if (t != tIDENT) {
                                        db_printf("Bad modifier\n");
                                        db_flush_lex();
                                        return;
                                }
                                /* save modifier */
                                strlcpy(modif, db_tok_string, sizeof(modif));

                        } else {
                                db_unread_token(t);
                                modif[0] = '\0';
                        }

                        if (db_expression(&addr)) { /*get address*/
                                db_dot = (db_addr_t) addr;
                                db_last_addr = db_dot;
                                have_addr = true;
                        } else {
                                addr = (db_expr_t) db_dot;
                                have_addr = false;
                        }

                        t = db_read_token();
                        if (t == tCOMMA) { /*Get count*/
                                if (!db_expression(&count)) {
                                        db_printf("Count missing\n");
                                        db_flush_lex();
                                        return;
                                }
                        } else {
                                db_unread_token(t);
                                count = -1;
                        }
                        if ((command->flag & CS_MORE) == 0) {
                                db_skip_to_eol();
                        }
                }
        }

        if (command != NULL && command->flag & CS_NOREPEAT) {
                *last_cmdp = NULL;
                last_count = 0;
        } else {
                *last_cmdp = command;
                last_count = count;
        }


        if (command != NULL) {
                /*
                 * Execute the command.
                 */
                if (command->fcn != NULL)
                        (*command->fcn)(addr, have_addr, count, modif);

                if (command->flag & CS_SET_DOT) {
                        /*
                         * If command changes dot, set dot to
                         * previous address displayed (if 'ed' style).
                         */
                        if (db_ed_style)
                                db_dot = db_prev;
                        else
                                db_dot = db_next;
                } else {
                        /*
                         * If command does not change dot,
                         * set 'next' location to be the same.
                         */
                        db_next = db_dot;
                }
        }
}

/*
 * Print help for commands
 */
static void
db_help_print_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
const char *modif)
{
        const struct db_command *command;
        int t;

        t = db_read_token();

        /* is there another command after the "help"? */
        if (t != tIDENT) {
                /* print base commands */
                db_cmd_list(&db_base_cmd_list);
                return;
        }

        command = db_read_command();
        if (command == NULL)
                return;

#ifdef DDB_VERBOSE_HELP
        db_printf("Command: %s\n", command->name);
        if (command->cmd_descr != NULL)
                db_printf(" Description: %s\n", command->cmd_descr);
        if (command->cmd_arg != NULL)
                db_printf(" Arguments: %s\n", command->cmd_arg);
        if (command->cmd_arg_help != NULL)
                db_printf(" Arguments description:\n%s\n",
                          command->cmd_arg_help);
        if ((command->cmd_arg == NULL) && (command->cmd_descr == NULL))
                db_printf(" No help message.\n");
#endif

        db_skip_to_eol();
}

/*ARGSUSED*/
static void
db_map_print_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
    const char *modif)
{
        bool full = false;

        if (modif[0] == 'f')
                full = true;

        if (have_addr == false)
                addr = (db_expr_t)(uintptr_t)db_read_ptr("kernel_map");

#ifdef _KERNEL
        uvm_map_printit((struct vm_map *)(uintptr_t) addr, full, db_printf);
#endif  /* XXX CRASH(8) */
}

/*ARGSUSED*/
static void
db_malloc_print_cmd(db_expr_t addr, bool have_addr,
    db_expr_t count, const char *modif)
{

#ifdef MALLOC_DEBUG
        if (!have_addr)
                addr = 0;

        debug_malloc_printit(db_printf, (vaddr_t) addr);
#else
        db_printf("The kernel is not built with the MALLOC_DEBUG option.\n");
#endif /* MALLOC_DEBUG */
}

/*ARGSUSED*/
static void
db_object_print_cmd(db_expr_t addr, bool have_addr,
    db_expr_t count, const char *modif)
{
        bool full = false;

        if (modif[0] == 'f')
                full = true;

#ifdef _KERNEL /* XXX CRASH(8) */
        uvm_object_printit((struct uvm_object *)(uintptr_t) addr, full,
            db_printf);
#endif
}

/*ARGSUSED*/
static void
db_page_print_cmd(db_expr_t addr, bool have_addr,
    db_expr_t count, const char *modif)
{
        bool full = false;

        if (modif[0] == 'f')
                full = true;

#ifdef _KERNEL /* XXX CRASH(8) */
        uvm_page_printit((struct vm_page *)(uintptr_t) addr, full, db_printf);
#endif
}

/*ARGSUSED*/
static void
db_show_all_pages(db_expr_t addr, bool have_addr,
    db_expr_t count, const char *modif)
{

#ifdef _KERNEL /* XXX CRASH(8) */
        uvm_page_printall(db_printf);
#endif
}

/*ARGSUSED*/
static void
db_buf_print_cmd(db_expr_t addr, bool have_addr,
    db_expr_t count, const char *modif)
{
        bool full = false;

        if (modif[0] == 'f')
                full = true;

#ifdef _KERNEL /* XXX CRASH(8) */
        vfs_buf_print((struct buf *)(uintptr_t) addr, full, db_printf);
#endif
}

/*ARGSUSED*/
static void
db_event_print_cmd(db_expr_t addr, bool have_addr,
    db_expr_t count, const char *modif)
{
        bool showzero = false;
        bool showall = true;
        bool showintr = false;
        bool showtrap = false;
        bool showmisc = false;
        struct evcnt ev, *evp;
        char buf[80];
        int i;

        i = 0;
        while (modif[i]) {
                switch (modif[i]) {
                case 'f':
                        showzero = true;
                        break;
                case 'i':
                        showintr = true;
                        showall = false;
                        break;
                case 't':
                        showtrap = true;
                        showall = false;
                        break;
                case 'm':
                        showmisc = true;
                        showall = false;
                        break;
                }
                i++;
        }

        if (showall)
                showmisc = showintr = showtrap = true;

        evp = (struct evcnt *)db_read_ptr("allevents");
        while (evp != NULL) {
                db_read_bytes((db_addr_t)evp, sizeof(ev), (char *)&ev);
                evp = ev.ev_list.tqe_next;
                if (ev.ev_count == 0 && !showzero)
                        continue;
                if (ev.ev_type == EVCNT_TYPE_INTR && !showintr)
                        continue;
                if (ev.ev_type == EVCNT_TYPE_TRAP && !showtrap)
                        continue;
                if (ev.ev_type == EVCNT_TYPE_MISC && !showmisc)
                        continue;
                db_read_bytes((db_addr_t)ev.ev_group, ev.ev_grouplen + 1, buf);
                db_printf("evcnt type %d: %s ", ev.ev_type, buf);
                db_read_bytes((db_addr_t)ev.ev_name, ev.ev_namelen + 1, buf);
                db_printf("%s = %lld\n", buf, (long long)ev.ev_count);
        }
}

/*ARGSUSED*/
static void
db_vnode_print_cmd(db_expr_t addr, bool have_addr,
    db_expr_t count, const char *modif)
{
        bool full = false;

        if (modif[0] == 'f')
                full = true;

#ifdef _KERNEL /* XXX CRASH(8) */
        vfs_vnode_print((struct vnode *)(uintptr_t) addr, full, db_printf);
#endif
}

/*ARGSUSED*/
static void
db_vmem_print_cmd(db_expr_t addr, bool have_addr,
    db_expr_t count, const char *modif)
{

#ifdef _KERNEL /* XXX CRASH(8) */
        vmem_print((uintptr_t) addr, modif, db_printf);
#endif
}

static void
db_mount_print_cmd(db_expr_t addr, bool have_addr,
    db_expr_t count, const char *modif)
{
        bool full = false;

        if (modif[0] == 'f')
                full = true;

#ifdef _KERNEL  /* XXX CRASH(8) */
        vfs_mount_print((struct mount *)(uintptr_t) addr, full, db_printf);
#endif
}

/*ARGSUSED*/
static void
db_mbuf_print_cmd(db_expr_t addr, bool have_addr,
    db_expr_t count, const char *modif)
{

#ifdef _KERNEL /* XXX CRASH(8) */
        m_print((const struct mbuf *)(uintptr_t) addr, modif, db_printf);
#endif
}

/*ARGSUSED*/
static void
db_pool_print_cmd(db_expr_t addr, bool have_addr,
    db_expr_t count, const char *modif)
{

#ifdef _KERNEL /* XXX CRASH(8) */
        pool_printit((struct pool *)(uintptr_t) addr, modif, db_printf);
#endif
}

/*ARGSUSED*/
static void
db_namecache_print_cmd(db_expr_t addr, bool have_addr,
    db_expr_t count, const char *modif)
{

#ifdef _KERNEL /* XXX CRASH(8) */
        namecache_print((struct vnode *)(uintptr_t) addr, db_printf);
#endif
}

/*ARGSUSED*/
static void
db_uvmexp_print_cmd(db_expr_t addr, bool have_addr,
    db_expr_t count, const char *modif)
{

#ifdef _KERNEL  /* XXX CRASH(8) */
        uvmexp_print(db_printf);
#endif
}

#ifdef UVMHIST
/*ARGSUSED*/
static void
db_uvmhist_print_cmd(db_expr_t addr, bool have_addr,
    db_expr_t count, const char *modif)
{

        uvmhist_print(db_printf);
}
#endif

/*ARGSUSED*/
static void
db_lock_print_cmd(db_expr_t addr, bool have_addr,
    db_expr_t count, const char *modif)
{

#ifdef _KERNEL  /* XXX CRASH(8) */
        lockdebug_lock_print((void *)(uintptr_t)addr, db_printf);
#endif
}

/*
 * Call random function:
 * !expr(arg,arg,arg)
 */
/*ARGSUSED*/
static void
db_fncall(db_expr_t addr, bool have_addr,
    db_expr_t count, const char *modif)
{
#ifdef _KERNEL
        db_expr_t       fn_addr;
#define MAXARGS         11
        db_expr_t       args[MAXARGS];
        int             nargs = 0;
        db_expr_t       retval;
        db_expr_t       (*func)(db_expr_t, ...);
        int             t;

        if (!db_expression(&fn_addr)) {
                db_printf("Bad function\n");
                db_flush_lex();
                return;
        }
        func = (db_expr_t (*)(db_expr_t, ...))(uintptr_t) fn_addr;

        t = db_read_token();
        if (t == tLPAREN) {
                if (db_expression(&args[0])) {
                        nargs++;
                        while ((t = db_read_token()) == tCOMMA) {
                                if (nargs == MAXARGS) {
                                        db_printf("Too many arguments\n");
                                        db_flush_lex();
                                        return;
                                }
                                if (!db_expression(&args[nargs])) {
                                        db_printf("Argument missing\n");
                                        db_flush_lex();
                                        return;
                                }
                                nargs++;
                        }
                        db_unread_token(t);
                }
                if (db_read_token() != tRPAREN) {
                        db_printf("?\n");
                        db_flush_lex();
                        return;
                }
        }
        db_skip_to_eol();

        while (nargs < MAXARGS) {
                args[nargs++] = 0;
        }

        retval = (*func)(args[0], args[1], args[2], args[3], args[4],
                         args[5], args[6], args[7], args[8], args[9]);
        db_printf("%s\n", db_num_to_str(retval));
#else   /* _KERNEL */
        db_printf("This command can only be used in-kernel.\n");
#endif  /* _KERNEL */
}

static void
db_reboot_cmd(db_expr_t addr, bool have_addr,
    db_expr_t count, const char *modif)
{
#ifdef _KERNEL
        db_expr_t bootflags;

        /* Flags, default to RB_AUTOBOOT */
        if (!db_expression(&bootflags))
                bootflags = (db_expr_t)RB_AUTOBOOT;
        if (db_read_token() != tEOL) {
                db_error("?\n");
                /*NOTREACHED*/
        }
        /*
         * We are leaving DDB, never to return upward.
         * Clear db_recover so that we can debug faults in functions
         * called from cpu_reboot.
         */
        db_recover = 0;
        cpu_reboot((int)bootflags, NULL);
#else   /* _KERNEL */
        db_printf("This command can only be used in-kernel.\n");
#endif  /* _KERNEL */
}

static void
db_sifting_cmd(db_expr_t addr, bool have_addr,
    db_expr_t count, const char *modif)
{
        int     mode, t;

        t = db_read_token();
        if (t == tSLASH) {
                t = db_read_token();
                if (t != tIDENT) {
                        bad_modifier:
                        db_printf("Bad modifier\n");
                        db_flush_lex();
                        return;
                }
                if (!strcmp(db_tok_string, "F"))
                        mode = 'F';
                else
                        goto bad_modifier;
                t = db_read_token();
        } else
                mode = 0;

        if (t == tIDENT)
                db_sifting(db_tok_string, mode);
        else {
                db_printf("Bad argument (non-string)\n");
                db_flush_lex();
        }
}

static void
db_stack_trace_cmd(db_expr_t addr, bool have_addr, db_expr_t count, const char *modif)
{
        register const char *cp = modif;
        register char c;
        void (*pr)(const char *, ...);

        pr = db_printf;
        while ((c = *cp++) != 0)
                if (c == 'l')
                        pr = (void (*)(const char *, ...))printf;

        if (count == -1)
                count = 65535;

        db_stack_trace_print(addr, have_addr, count, modif, pr);
}

static void
db_sync_cmd(db_expr_t addr, bool have_addr,
    db_expr_t count, const char *modif)
{
#ifdef _KERNEL
        /*
         * We are leaving DDB, never to return upward.
         * Clear db_recover so that we can debug faults in functions
         * called from cpu_reboot.
         */
        db_recover = 0;
        panicstr = "dump forced via kernel debugger";
        cpu_reboot(RB_DUMP, NULL);
#else   /* _KERNEL */
        db_printf("This command can only be used in-kernel.\n");
#endif  /* _KERNEL */
}

/*
 * Describe what an address is
 */
void
db_whatis_cmd(db_expr_t address, bool have_addr,
    db_expr_t count, const char *modif)
{
        const uintptr_t addr = (uintptr_t)address;

        db_lwp_whatis(addr, db_printf);
#ifdef _KERNEL  /* XXX CRASH(8) */
        pool_whatis(addr, db_printf);
        vmem_whatis(addr, db_printf);
        uvm_whatis(addr, db_printf);
        module_whatis(addr, db_printf);
#endif
}