common/mdb/mdb_modapi.c

	mdb_modapi.c revision 8a6a72fd51dfee674c6daa8a222f68b1532516ab
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

#include <mdb/mdb_modapi.h>
#include <mdb/mdb_module.h>
#include <mdb/mdb_string.h>
#include <mdb/mdb_debug.h>
#include <mdb/mdb_callb.h>
#include <mdb/mdb_dump.h>
#include <mdb/mdb_err.h>
#include <mdb/mdb_io.h>
#include <mdb/mdb_lex.h>
#include <mdb/mdb_frame.h>
#include <mdb/mdb.h>

/*
 * Private callback structure for implementing mdb_walk_dcmd, below.
 */
typedef struct {
    mdb_idcmd_t *dw_dcmd;
    mdb_argvec_t dw_argv;
    uint_t dw_flags;
} dcmd_walk_arg_t;

/*
 * Global properties which modules are allowed to look at.  These are
 * re-initialized by the target activation callbacks.
 */
int mdb_prop_postmortem = FALSE;    /* Are we examining a dump? */
int mdb_prop_kernel = FALSE;        /* Are we examining a kernel? */
int mdb_prop_datamodel = 0;     /* Data model (see mdb_target_impl.h) */

ssize_t
mdb_vread(void *buf, size_t nbytes, uintptr_t addr)
{
    ssize_t rbytes = mdb_tgt_vread(mdb.m_target, buf, nbytes, addr);

    if (rbytes > 0 && rbytes < nbytes)
        return (set_errbytes(rbytes, nbytes));

    return (rbytes);
}

ssize_t
mdb_vwrite(const void *buf, size_t nbytes, uintptr_t addr)
{
    return (mdb_tgt_vwrite(mdb.m_target, buf, nbytes, addr));
}

ssize_t
mdb_fread(void *buf, size_t nbytes, uintptr_t addr)
{
    ssize_t rbytes = mdb_tgt_fread(mdb.m_target, buf, nbytes, addr);

    if (rbytes > 0 && rbytes < nbytes)
        return (set_errbytes(rbytes, nbytes));

    return (rbytes);
}

ssize_t
mdb_fwrite(const void *buf, size_t nbytes, uintptr_t addr)
{
    return (mdb_tgt_fwrite(mdb.m_target, buf, nbytes, addr));
}

ssize_t
mdb_pread(void *buf, size_t nbytes, physaddr_t addr)
{
    ssize_t rbytes = mdb_tgt_pread(mdb.m_target, buf, nbytes, addr);

    if (rbytes > 0 && rbytes < nbytes)
        return (set_errbytes(rbytes, nbytes));

    return (rbytes);
}

ssize_t
mdb_pwrite(const void *buf, size_t nbytes, physaddr_t addr)
{
    return (mdb_tgt_pwrite(mdb.m_target, buf, nbytes, addr));
}

ssize_t
mdb_readstr(char *buf, size_t nbytes, uintptr_t addr)
{
    return (mdb_tgt_readstr(mdb.m_target, MDB_TGT_AS_VIRT,
        buf, nbytes, addr));
}

ssize_t
mdb_writestr(const char *buf, uintptr_t addr)
{
    return (mdb_tgt_writestr(mdb.m_target, MDB_TGT_AS_VIRT, buf, addr));
}

ssize_t
mdb_readsym(void *buf, size_t nbytes, const char *name)
{
    ssize_t rbytes = mdb_tgt_readsym(mdb.m_target, MDB_TGT_AS_VIRT,
        buf, nbytes, MDB_TGT_OBJ_EXEC, name);

    if (rbytes > 0 && rbytes < nbytes)
        return (set_errbytes(rbytes, nbytes));

    return (rbytes);
}

ssize_t
mdb_writesym(const void *buf, size_t nbytes, const char *name)
{
    return (mdb_tgt_writesym(mdb.m_target, MDB_TGT_AS_VIRT,
        buf, nbytes, MDB_TGT_OBJ_EXEC, name));
}

ssize_t
mdb_readvar(void *buf, const char *name)
{
    GElf_Sym sym;

    if (mdb_tgt_lookup_by_name(mdb.m_target, MDB_TGT_OBJ_EXEC,
        name, &sym, NULL))
        return (-1);

    if (mdb_tgt_vread(mdb.m_target, buf, sym.st_size,
        (uintptr_t)sym.st_value) == sym.st_size)
        return ((ssize_t)sym.st_size);

    return (-1);
}

ssize_t
mdb_writevar(const void *buf, const char *name)
{
    GElf_Sym sym;

    if (mdb_tgt_lookup_by_name(mdb.m_target, MDB_TGT_OBJ_EXEC,
        name, &sym, NULL))
        return (-1);

    if (mdb_tgt_vwrite(mdb.m_target, buf, sym.st_size,
        (uintptr_t)sym.st_value) == sym.st_size)
        return ((ssize_t)sym.st_size);

    return (-1);
}

int
mdb_lookup_by_name(const char *name, GElf_Sym *sym)
{
    return (mdb_lookup_by_obj(MDB_TGT_OBJ_EXEC, name, sym));
}

int
mdb_lookup_by_obj(const char *obj, const char *name, GElf_Sym *sym)
{
    return (mdb_tgt_lookup_by_name(mdb.m_target, obj, name, sym, NULL));
}

int
mdb_lookup_by_addr(uintptr_t addr, uint_t flags, char *buf,
    size_t nbytes, GElf_Sym *sym)
{
    return (mdb_tgt_lookup_by_addr(mdb.m_target, addr, flags,
        buf, nbytes, sym, NULL));
}

u_longlong_t
mdb_strtoull(const char *s)
{
    int radix = mdb.m_radix;

    if (s[0] == '0') {
        switch (s[1]) {
        case 'I':
        case 'i':
            radix = 2;
            s += 2;
            break;
        case 'O':
        case 'o':
            radix = 8;
            s += 2;
            break;
        case 'T':
        case 't':
            radix = 10;
            s += 2;
            break;
        case 'X':
        case 'x':
            radix = 16;
            s += 2;
            break;
        }
    }

    return (strtonum(s, radix));
}

size_t
mdb_snprintf(char *buf, size_t nbytes, const char *format, ...)
{
    va_list alist;

    va_start(alist, format);
    nbytes = mdb_iob_vsnprintf(buf, nbytes, format, alist);
    va_end(alist);

    return (nbytes);
}

void
mdb_printf(const char *format, ...)
{
    va_list alist;

    va_start(alist, format);
    mdb_iob_vprintf(mdb.m_out, format, alist);
    va_end(alist);
}

void
mdb_warn(const char *format, ...)
{
    va_list alist;

    va_start(alist, format);
    vwarn(format, alist);
    va_end(alist);
}

void
mdb_flush(void)
{
    mdb_iob_flush(mdb.m_out);
}

/*
 * Convert an object of len bytes pointed to by srcraw between
 * network-order and host-order and store in dstraw.  The length len must
 * be the actual length of the objects pointed to by srcraw and dstraw (or
 * zero) or the results are undefined.  srcraw and dstraw may be the same,
 * in which case the object is converted in-place.  Note that this routine
 * will convert from host-order to network-order or network-order to
 * host-order, since the conversion is the same in either case.
 */
/* ARGSUSED */
void
mdb_nhconvert(void *dstraw, const void *srcraw, size_t len)
{
#ifdef  _LITTLE_ENDIAN
    uint8_t b1, b2;
    uint8_t *dst, *src;
    size_t i;

    dst = (uint8_t *)dstraw;
    src = (uint8_t *)srcraw;
    for (i = 0; i < len / 2; i++) {
        b1 = src[i];
        b2 = src[len - i - 1];
        dst[i] = b2;
        dst[len - i - 1] = b1;
    }
#else
    if (dstraw != srcraw)
        bcopy(srcraw, dstraw, len);
#endif
}


/*
 * Bit formatting functions: Note the interesting use of UM_GC here to
 * allocate a buffer for the caller which will be automatically freed
 * when the dcmd completes or is forcibly aborted.
 */

#define NBNB            (NBBY / 2)  /* number of bits per nibble */
#define SETBIT(buf, j, c) { \
    if (((j) + 1) % (NBNB + 1) == 0) \
        (buf)[(j)++] = ' '; \
    (buf)[(j)++] = (c); \
}

const char *
mdb_one_bit(int width, int bit, int on)
{
    int i, j = 0;
    char *buf;

    buf = mdb_zalloc(width + (width / NBNB) + 2, UM_GC | UM_SLEEP);

    for (i = --width; i > bit; i--)
        SETBIT(buf, j, '.');

    SETBIT(buf, j, on ? '1' : '0');

    for (i = bit - 1; i >= 0; i--)
        SETBIT(buf, j, '.');

    return (buf);
}

const char *
mdb_inval_bits(int width, int start, int stop)
{
    int i, j = 0;
    char *buf;

    buf = mdb_zalloc(width + (width / NBNB) + 2, UM_GC | UM_SLEEP);

    for (i = --width; i > stop; i--)
        SETBIT(buf, j, '.');

    for (i = stop; i >= start; i--)
        SETBIT(buf, j, 'x');

    for (; i >= 0; i--)
        SETBIT(buf, j, '.');

    return (buf);
}

ulong_t
mdb_inc_indent(ulong_t i)
{
    if (mdb_iob_getflags(mdb.m_out) & MDB_IOB_INDENT) {
        ulong_t margin = mdb_iob_getmargin(mdb.m_out);
        mdb_iob_margin(mdb.m_out, margin + i);
        return (margin);
    }

    mdb_iob_margin(mdb.m_out, i);
    mdb_iob_setflags(mdb.m_out, MDB_IOB_INDENT);
    return (0);
}

ulong_t
mdb_dec_indent(ulong_t i)
{
    if (mdb_iob_getflags(mdb.m_out) & MDB_IOB_INDENT) {
        ulong_t margin = mdb_iob_getmargin(mdb.m_out);

        if (margin < i || margin - i == 0) {
            mdb_iob_clrflags(mdb.m_out, MDB_IOB_INDENT);
            mdb_iob_margin(mdb.m_out, MDB_IOB_DEFMARGIN);
        } else
            mdb_iob_margin(mdb.m_out, margin - i);

        return (margin);
    }

    return (0);
}

int
mdb_eval(const char *s)
{
    mdb_frame_t *ofp = mdb.m_fmark;
    mdb_frame_t *fp = mdb.m_frame;
    int err;

    if (s == NULL)
        return (set_errno(EINVAL));

    /*
     * Push m_in down onto the input stack, then set m_in to point to the
     * i/o buffer for our command string, and reset the frame marker.
     * The mdb_run() function returns when the new m_in iob reaches EOF.
     */
    mdb_iob_stack_push(&fp->f_istk, mdb.m_in, yylineno);
    mdb.m_in = mdb_iob_create(mdb_strio_create(s), MDB_IOB_RDONLY);

    mdb.m_fmark = NULL;
    err = mdb_run();
    mdb.m_fmark = ofp;

    /*
     * Now pop the old standard input stream and restore mdb.m_in and
     * the parser's saved current line number.
     */
    mdb.m_in = mdb_iob_stack_pop(&fp->f_istk);
    yylineno = mdb_iob_lineno(mdb.m_in);

    /*
     * If mdb_run() returned an error, propagate this backward
     * up the stack of debugger environment frames.
     */
    if (MDB_ERR_IS_FATAL(err))
        longjmp(fp->f_pcb, err);

    if (err == MDB_ERR_PAGER || err == MDB_ERR_SIGINT)
        return (set_errno(EMDB_CANCEL));

    if (err != 0)
        return (set_errno(EMDB_EVAL));

    return (0);
}

void
mdb_set_dot(uintmax_t addr)
{
    mdb_nv_set_value(mdb.m_dot, addr);
    mdb.m_incr = 0;
}

uintmax_t
mdb_get_dot(void)
{
    return (mdb_nv_get_value(mdb.m_dot));
}

static int
walk_step(mdb_wcb_t *wcb)
{
    mdb_wcb_t *nwcb = wcb->w_lyr_head;
    int status;

    /*
     * If the control block has no layers, we just invoke the walker's
     * step function and return status indicating whether to continue
     * or stop.  If the control block has layers, we need to invoke
     * ourself recursively for the next layer, until eventually we
     * percolate down to an unlayered walk.
     */
    if (nwcb == NULL)
        return (wcb->w_walker->iwlk_step(&wcb->w_state));

    if ((status = walk_step(nwcb)) != WALK_NEXT) {
        wcb->w_lyr_head = nwcb->w_lyr_link;
        nwcb->w_lyr_link = NULL;
        mdb_wcb_destroy(nwcb);
    }

    if (status == WALK_DONE && wcb->w_lyr_head != NULL)
        return (WALK_NEXT);

    return (status);
}

static int
walk_common(mdb_wcb_t *wcb)
{
    int status, rval = 0;
    mdb_frame_t *pfp;

    /*
     * Enter the control block in the active list so that mdb can clean
     * up after it in case we abort out of the current command.
     */
    if ((pfp = mdb_list_prev(mdb.m_frame)) != NULL && pfp->f_pcmd != NULL)
        mdb_wcb_insert(wcb, pfp);
    else
        mdb_wcb_insert(wcb, mdb.m_frame);

    /*
     * The per-walk constructor performs private buffer initialization
     * and locates whatever symbols are necessary.
     */
    if ((status = wcb->w_walker->iwlk_init(&wcb->w_state)) != WALK_NEXT) {
        if (status != WALK_DONE)
            rval = set_errno(EMDB_WALKINIT);
        goto done;
    }

    /*
     * Mark wcb to indicate that walk_init has been called (which means
     * we can call walk_fini if the walk is aborted at this point).
     */
    wcb->w_inited = TRUE;

    while (walk_step(wcb) == WALK_NEXT)
        continue;
done:
    if ((pfp = mdb_list_prev(mdb.m_frame)) != NULL && pfp->f_pcmd != NULL)
        mdb_wcb_delete(wcb, pfp);
    else
        mdb_wcb_delete(wcb, mdb.m_frame);

    mdb_wcb_destroy(wcb);
    return (rval);
}

int
mdb_pwalk(const char *name, mdb_walk_cb_t func, void *data, uintptr_t addr)
{
    mdb_iwalker_t *iwp = mdb_walker_lookup(name);

    if (func == NULL)
        return (set_errno(EINVAL));

    if (iwp != NULL)
        return (walk_common(mdb_wcb_create(iwp, func, data, addr)));

    return (-1); /* errno is set for us */
}

int
mdb_walk(const char *name, mdb_walk_cb_t func, void *data)
{
    return (mdb_pwalk(name, func, data, NULL));
}

/*ARGSUSED*/
static int
walk_dcmd(uintptr_t addr, const void *ignored, dcmd_walk_arg_t *dwp)
{
    int status = mdb_call_idcmd(dwp->dw_dcmd, addr, 1, dwp->dw_flags,
        &dwp->dw_argv, NULL, NULL);

    if (status == DCMD_USAGE || status == DCMD_ABORT)
        return (WALK_ERR);

    dwp->dw_flags &= ~DCMD_LOOPFIRST;
    return (WALK_NEXT);
}

int
mdb_pwalk_dcmd(const char *wname, const char *dcname,
    int argc, const mdb_arg_t *argv, uintptr_t addr)
{
    mdb_argvec_t args;
    dcmd_walk_arg_t dw;
    mdb_iwalker_t *iwp;
    mdb_wcb_t *wcb;
    int status;

    if (wname == NULL || dcname == NULL)
        return (set_errno(EINVAL));

    if ((dw.dw_dcmd = mdb_dcmd_lookup(dcname)) == NULL)
        return (-1); /* errno is set for us */

    if ((iwp = mdb_walker_lookup(wname)) == NULL)
        return (-1); /* errno is set for us */

    args.a_data = (mdb_arg_t *)argv;
    args.a_nelems = args.a_size = argc;

    mdb_argvec_create(&dw.dw_argv);
    mdb_argvec_copy(&dw.dw_argv, &args);
    dw.dw_flags = DCMD_LOOP | DCMD_LOOPFIRST | DCMD_ADDRSPEC;

    wcb = mdb_wcb_create(iwp, (mdb_walk_cb_t)walk_dcmd, &dw, addr);
    status = walk_common(wcb);

    mdb_argvec_zero(&dw.dw_argv);
    mdb_argvec_destroy(&dw.dw_argv);

    return (status);
}

int
mdb_walk_dcmd(const char *wname, const char *dcname,
    int argc, const mdb_arg_t *argv)
{
    return (mdb_pwalk_dcmd(wname, dcname, argc, argv, NULL));
}

/*ARGSUSED*/
static int
layered_walk_step(uintptr_t addr, const void *data, mdb_wcb_t *wcb)
{
    /*
     * Prior to calling the top-level walker's step function, reset its
     * mdb_walk_state_t walk_addr and walk_layer members to refer to the
     * target virtual address and data buffer of the underlying object.
     */
    wcb->w_state.walk_addr = addr;
    wcb->w_state.walk_layer = data;

    return (wcb->w_walker->iwlk_step(&wcb->w_state));
}

int
mdb_layered_walk(const char *wname, mdb_walk_state_t *wsp)
{
    mdb_wcb_t *cwcb, *wcb;
    mdb_iwalker_t *iwp;

    if (wname == NULL || wsp == NULL)
        return (set_errno(EINVAL));

    if ((iwp = mdb_walker_lookup(wname)) == NULL)
        return (-1); /* errno is set for us */

    if ((cwcb = mdb_wcb_from_state(wsp)) == NULL)
        return (set_errno(EMDB_BADWCB));

    if (cwcb->w_walker == iwp)
        return (set_errno(EMDB_WALKLOOP));

    wcb = mdb_wcb_create(iwp, (mdb_walk_cb_t)layered_walk_step,
        cwcb, wsp->walk_addr);

    if (iwp->iwlk_init(&wcb->w_state) != WALK_NEXT) {
        mdb_wcb_destroy(wcb);
        return (set_errno(EMDB_WALKINIT));
    }

    wcb->w_inited = TRUE;

    mdb_dprintf(MDB_DBG_WALK, "added %s`%s as %s`%s layer\n",
        iwp->iwlk_modp->mod_name, iwp->iwlk_name,
        cwcb->w_walker->iwlk_modp->mod_name, cwcb->w_walker->iwlk_name);

    if (cwcb->w_lyr_head != NULL) {
        for (cwcb = cwcb->w_lyr_head; cwcb->w_lyr_link != NULL; )
            cwcb = cwcb->w_lyr_link;
        cwcb->w_lyr_link = wcb;
    } else
        cwcb->w_lyr_head = wcb;

    return (0);
}

int
mdb_call_dcmd(const char *name, uintptr_t dot, uint_t flags,
    int argc, const mdb_arg_t *argv)
{
    mdb_idcmd_t *idcp;
    mdb_argvec_t args;
    int status;

    if (name == NULL || argc < 0)
        return (set_errno(EINVAL));

    if ((idcp = mdb_dcmd_lookup(name)) == NULL)
        return (-1); /* errno is set for us */

    args.a_data = (mdb_arg_t *)argv;
    args.a_nelems = args.a_size = argc;
    status = mdb_call_idcmd(idcp, dot, 1, flags, &args, NULL, NULL);

    if (status == DCMD_ERR || status == DCMD_ABORT)
        return (set_errno(EMDB_DCFAIL));

    if (status == DCMD_USAGE)
        return (set_errno(EMDB_DCUSAGE));

    return (0);
}

int
mdb_add_walker(const mdb_walker_t *wp)
{
    mdb_module_t *mp;

    if (mdb.m_lmod == NULL) {
        mdb_cmd_t *cp = mdb.m_frame->f_cp;
        mp = cp->c_dcmd->idc_modp;
    } else
        mp = mdb.m_lmod;

    return (mdb_module_add_walker(mp, wp, 0));
}

int
mdb_remove_walker(const char *name)
{
    mdb_module_t *mp;

    if (mdb.m_lmod == NULL) {
        mdb_cmd_t *cp = mdb.m_frame->f_cp;
        mp = cp->c_dcmd->idc_modp;
    } else
        mp = mdb.m_lmod;

    return (mdb_module_remove_walker(mp, name));
}

void
mdb_get_pipe(mdb_pipe_t *p)
{
    mdb_cmd_t *cp = mdb.m_frame->f_cp;
    mdb_addrvec_t *adp = &cp->c_addrv;

    if (p == NULL) {
        warn("dcmd failure: mdb_get_pipe invoked with NULL pointer\n");
        longjmp(mdb.m_frame->f_pcb, MDB_ERR_API);
    }

    if (adp->ad_nelems != 0) {
        ASSERT(adp->ad_ndx != 0);
        p->pipe_data = &adp->ad_data[adp->ad_ndx - 1];
        p->pipe_len = adp->ad_nelems - adp->ad_ndx + 1;
        adp->ad_ndx = adp->ad_nelems;
    } else {
        p->pipe_data = NULL;
        p->pipe_len = 0;
    }
}

void
mdb_set_pipe(const mdb_pipe_t *p)
{
    mdb_cmd_t *cp = mdb.m_frame->f_pcmd;

    if (p == NULL) {
        warn("dcmd failure: mdb_set_pipe invoked with NULL pointer\n");
        longjmp(mdb.m_frame->f_pcb, MDB_ERR_API);
    }

    if (cp != NULL) {
        size_t nbytes = sizeof (uintptr_t) * p->pipe_len;

        mdb_cmd_reset(cp);
        cp->c_addrv.ad_data = mdb_alloc(nbytes, UM_SLEEP);
        bcopy(p->pipe_data, cp->c_addrv.ad_data, nbytes);
        cp->c_addrv.ad_nelems = p->pipe_len;
        cp->c_addrv.ad_size = p->pipe_len;
    }
}

ssize_t
mdb_get_xdata(const char *name, void *buf, size_t nbytes)
{
    return (mdb_tgt_getxdata(mdb.m_target, name, buf, nbytes));
}

/*
 * Private structure and function for implementing mdb_dumpptr on top
 * of mdb_dump_internal
 */
typedef struct dptrdat {
    mdb_dumpptr_cb_t func;
    void *arg;
} dptrdat_t;

static ssize_t
mdb_dump_aux_ptr(void *buf, size_t nbyte, uint64_t offset, void *arg)
{
    dptrdat_t *dat = arg;

    return (dat->func(buf, nbyte, offset, dat->arg));
}

/*
 * Private structure and function for handling callbacks which return
 * EMDB_PARTIAL
 */
typedef struct d64dat {
    mdb_dump64_cb_t func;
    void *arg;
} d64dat_t;

static ssize_t
mdb_dump_aux_partial(void *buf, size_t nbyte, uint64_t offset, void *arg)
{
    d64dat_t *dat = arg;
    int result;
    int count;

    result = dat->func(buf, nbyte, offset, dat->arg);
    if (result == -1 && errno == EMDB_PARTIAL) {
        count = 0;
        do {
            result = dat->func((char *)buf + count, 1,
                offset + count, dat->arg);
            if (result == 1)
                count++;
        } while (count < nbyte && result == 1);
        if (count)
            result = count;
    }

    return (result);
}

int
mdb_dumpptr(uintptr_t addr, size_t len, uint_t flags, mdb_dumpptr_cb_t fp,
    void *arg)
{
    dptrdat_t dat;
    d64dat_t dat64;

    dat.func = fp;
    dat.arg = arg;
    dat64.func = mdb_dump_aux_ptr;
    dat64.arg = &dat;
    return (mdb_dump_internal(addr, len, flags, mdb_dump_aux_partial,
        &dat64, sizeof (uintptr_t)));
}

int
mdb_dump64(uint64_t addr, uint64_t len, uint_t flags, mdb_dump64_cb_t fp,
    void *arg)
{
    d64dat_t dat64;

    dat64.func = fp;
    dat64.arg = arg;
    return (mdb_dump_internal(addr, len, flags, mdb_dump_aux_partial,
        &dat64, sizeof (uint64_t)));
}

int
mdb_get_state(void)
{
    mdb_tgt_status_t ts;

    (void) mdb_tgt_status(mdb.m_target, &ts);

    return (ts.st_state);
}

void *
mdb_callback_add(int class, mdb_callback_f fp, void *arg)
{
    mdb_module_t *m;

    if (class != MDB_CALLBACK_STCHG && class != MDB_CALLBACK_PROMPT) {
        (void) set_errno(EINVAL);
        return (NULL);
    }

    if (mdb.m_lmod != NULL)
        m = mdb.m_lmod;
    else
        m = mdb.m_frame->f_cp->c_dcmd->idc_modp;

    return (mdb_callb_add(m, class, fp, arg));
}

void
mdb_callback_remove(void *hdl)
{
    mdb_callb_remove(hdl);
}