common/kmdb/kdrv.c

/*
 * 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 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */


/*
 * The driver portion of kmdb, which manages /dev/kmdb and passes requests along
 * to the kmdb misc module (kmdbmod).
 */

#include <sys/conf.h>
#include <sys/stat.h>
#include <sys/modctl.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>
#include <sys/open.h>
#include <sys/kobj.h>
#include <sys/kdi.h>
#include <sys/policy.h>
#include <sys/kobj_impl.h>
#include <sys/kmdb.h>
#include <sys/sysmacros.h>
#include <sys/consdev.h>

#define KDRV_CFG_MAXLEN     2048

static dev_info_t       *kdrv_dip;

/*ARGSUSED*/
static int
kdrv_open(dev_t *dev, int openflags, int otyp, cred_t *credp)
{
    if (otyp != OTYP_CHR)
        return (EINVAL);

    if (secpolicy_kmdb(credp) != 0)
        return (EPERM);

    return (0);
}

/*ARGSUSED*/
static int
kdrv_close(dev_t dev, int openflags, int otyp, cred_t *credp)
{
    return (0);
}

typedef struct kdrv_flags_map {
    const char *fm_name;
    int fm_defval;
    uint_t fm_flag;
} kdrv_flags_map_t;

static const kdrv_flags_map_t kdrv_flags_map[] = {
    { "kmdb-auto-entry", 1, KMDB_F_AUTO_ENTRY },
    { "kmdb-trap-noswitch", 0, KMDB_F_TRAP_NOSWITCH },
    { "kmdb-driver-debug", 0, KMDB_F_DRV_DEBUG },
    { NULL }
};

static int
kdrv_activate(intptr_t arg)
{
    uint_t flags;
    size_t memsz;
    char *cfg;
    size_t got;
    int i, rc;

#if defined(__x86)
    if (cons_polledio == NULL) {
        cmn_err(CE_NOTE, "kmdb not supported: no console polled I/O");
        return (ENOTSUP);
    }
#endif

    memsz = ddi_prop_get_int(DDI_DEV_T_ANY, kdrv_dip,
        DDI_PROP_DONTPASS, "kmdb-memseg-size", 0);

    for (flags = 0, i = 0; kdrv_flags_map[i].fm_name != NULL; i++) {
        const kdrv_flags_map_t *fm = &kdrv_flags_map[i];
        if (ddi_prop_get_int(DDI_DEV_T_ANY, kdrv_dip, DDI_PROP_DONTPASS,
            (char *)fm->fm_name, fm->fm_defval))
            flags |= fm->fm_flag;
    }

    cfg = kmem_alloc(KDRV_CFG_MAXLEN, KM_SLEEP);

    if ((rc = copyinstr((caddr_t)arg, cfg, KDRV_CFG_MAXLEN, &got)) != 0) {
        kmem_free(cfg, KDRV_CFG_MAXLEN);
        return (rc == ENAMETOOLONG ? E2BIG : EFAULT);
    }

    rc = kctl_modload_activate(memsz, cfg, flags);

    kmem_free(cfg, KDRV_CFG_MAXLEN);

    return (rc);
}

static int
kdrv_deactivate(void)
{
    return (kctl_deactivate());
}

/*ARGSUSED*/
static int
kdrv_ioctl(dev_t dev, int cmd, intptr_t arg, int flags, cred_t *credp,
    int *rvalp)
{
    switch (cmd) {
    case KMDB_IOC_START:
        return (kdrv_activate(arg));

    case KMDB_IOC_STOP:
        return (kdrv_deactivate());

    default:
        return (EINVAL);
    }
}

/*ARGSUSED*/
static int
kdrv_getinfo(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg, void **result)
{
    int error = DDI_SUCCESS;

    switch (infocmd) {
    case DDI_INFO_DEVT2DEVINFO:
        *result = kdrv_dip;
        break;
    case DDI_INFO_DEVT2INSTANCE:
        *result = (void *)(uintptr_t)getminor((dev_t)arg);
        break;
    default:
        *result = NULL;
        error = DDI_FAILURE;
    }

    return (error);
}

static int
kdrv_attach(dev_info_t *dip, ddi_attach_cmd_t cmd)
{
    if (cmd != DDI_ATTACH)
        return (DDI_FAILURE);

    if (ddi_create_minor_node(dip, ddi_get_name(dip), S_IFCHR,
        ddi_get_instance(dip), DDI_PSEUDO, 0) != DDI_SUCCESS)
        return (DDI_FAILURE);

    kdrv_dip = dip;

    if (kctl_attach(dip) != 0)
        return (DDI_FAILURE);

    return (DDI_SUCCESS);
}

static int
kdrv_detach(dev_info_t *dip, ddi_detach_cmd_t cmd)
{
    if (cmd != DDI_DETACH)
        return (DDI_FAILURE);

    if (kctl_detach() == EBUSY)
        return (DDI_FAILURE);

    ddi_remove_minor_node(dip, NULL);

    return (DDI_SUCCESS);
}

static struct cb_ops kdrv_cb_ops = {
    kdrv_open,
    kdrv_close,
    nodev,          /* not a block driver   */
    nodev,          /* no print routine */
    nodev,          /* no dump routine  */
    nodev,          /* no read routine  */
    nodev,          /* no write routine */
    kdrv_ioctl,
    nodev,          /* no devmap routine    */
    nodev,          /* no mmap routine  */
    nodev,          /* no segmap routine    */
    nochpoll,       /* no chpoll routine    */
    ddi_prop_op,
    0,          /* not a STREAMS driver */
    D_NEW | D_MP,       /* safe for multi-thread/multi-processor */
};

static struct dev_ops kdrv_ops = {
    DEVO_REV,       /* devo_rev */
    0,          /* devo_refcnt */
    kdrv_getinfo,       /* devo_getinfo */
    nulldev,        /* devo_identify */
    nulldev,        /* devo_probe */
    kdrv_attach,        /* devo_attach */
    kdrv_detach,        /* devo_detach */
    nodev,          /* devo_reset */
    &kdrv_cb_ops,       /* devo_cb_ops */
    (struct bus_ops *)0,    /* devo_bus_ops */
    NULL,           /* devo_power */
    ddi_quiesce_not_needed,     /* devo_quiesce */
};

static struct modldrv modldrv = {
    &mod_driverops,
    "kmdb driver",
    &kdrv_ops
};

static struct modlinkage modlinkage = {
    MODREV_1,
    (void *)&modldrv,
    NULL
};

int
_init(void)
{
    return (mod_install(&modlinkage));
}

int
_info(struct modinfo *modinfop)
{
    return (mod_info(&modlinkage, modinfop));
}

int
_fini(void)
{
    return (mod_remove(&modlinkage));
}