d/freebsd-dev
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
f17aea5366
freebsd-dev/sys/kern/kern_conf.c
Kyle Evans e3f35d562f Remove the remnants of SI_CHEAPCLONE 
SI_CHEAPCLONE was introduced in r66067 for use with cloned bpfs. It was
later also used in tty, tun, tap at points. The rough timeline for being
removed in each of these is as follows:

- r181690: bpf switched to use cdevpriv API by ed@
- r181905: ed@ rewrote the TTY later to be mpsafe
- r204464: kib@ removes it from tun/tap, declaring it unused

I've not yet been able to dig up any other consumers in the intervening 9
years. It is no longer set on any devices in the tree and leaves an
interesting situation in make_dev_sv where we're ok with the device already
being set SI_NAMED.
2019-10-05 21:52:06 +00:00

1571 lines
36 KiB
C
Raw Blame History

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 1999-2002 Poul-Henning Kamp
* All rights reserved.
*
* 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 AUTHOR 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 AUTHOR 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/bio.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/module.h>
#include <sys/malloc.h>
#include <sys/conf.h>
#include <sys/vnode.h>
#include <sys/queue.h>
#include <sys/poll.h>
#include <sys/sx.h>
#include <sys/ctype.h>
#include <sys/ucred.h>
#include <sys/taskqueue.h>
#include <machine/stdarg.h>
#include <fs/devfs/devfs_int.h>
#include <vm/vm.h>
static MALLOC_DEFINE(M_DEVT, "cdev", "cdev storage");
struct mtx devmtx;
static void destroy_devl(struct cdev *dev);
static int destroy_dev_sched_cbl(struct cdev *dev,
void (*cb)(void *), void *arg);
static void destroy_dev_tq(void *ctx, int pending);
static int make_dev_credv(int flags, struct cdev **dres, struct cdevsw *devsw,
int unit, struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt,
va_list ap);
static struct cdev_priv_list cdevp_free_list =
TAILQ_HEAD_INITIALIZER(cdevp_free_list);
static SLIST_HEAD(free_cdevsw, cdevsw) cdevsw_gt_post_list =
SLIST_HEAD_INITIALIZER(cdevsw_gt_post_list);
void
dev_lock(void)
{
mtx_lock(&devmtx);
}
/*
* Free all the memory collected while the cdev mutex was
* locked. Since devmtx is after the system map mutex, free() cannot
* be called immediately and is postponed until cdev mutex can be
* dropped.
*/
static void
dev_unlock_and_free(void)
{
struct cdev_priv_list cdp_free;
struct free_cdevsw csw_free;
struct cdev_priv *cdp;
struct cdevsw *csw;
mtx_assert(&devmtx, MA_OWNED);
/*
* Make the local copy of the list heads while the dev_mtx is
* held. Free it later.
*/
TAILQ_INIT(&cdp_free);
TAILQ_CONCAT(&cdp_free, &cdevp_free_list, cdp_list);
csw_free = cdevsw_gt_post_list;
SLIST_INIT(&cdevsw_gt_post_list);
mtx_unlock(&devmtx);
while ((cdp = TAILQ_FIRST(&cdp_free)) != NULL) {
TAILQ_REMOVE(&cdp_free, cdp, cdp_list);
devfs_free(&cdp->cdp_c);
}
while ((csw = SLIST_FIRST(&csw_free)) != NULL) {
SLIST_REMOVE_HEAD(&csw_free, d_postfree_list);
free(csw, M_DEVT);
}
}
static void
dev_free_devlocked(struct cdev *cdev)
{
struct cdev_priv *cdp;
mtx_assert(&devmtx, MA_OWNED);
cdp = cdev2priv(cdev);
KASSERT((cdp->cdp_flags & CDP_UNREF_DTR) == 0,
("destroy_dev() was not called after delist_dev(%p)", cdev));
TAILQ_INSERT_HEAD(&cdevp_free_list, cdp, cdp_list);
}
static void
cdevsw_free_devlocked(struct cdevsw *csw)
{
mtx_assert(&devmtx, MA_OWNED);
SLIST_INSERT_HEAD(&cdevsw_gt_post_list, csw, d_postfree_list);
}
void
dev_unlock(void)
{
mtx_unlock(&devmtx);
}
void
dev_ref(struct cdev *dev)
{
mtx_assert(&devmtx, MA_NOTOWNED);
mtx_lock(&devmtx);
dev->si_refcount++;
mtx_unlock(&devmtx);
}
void
dev_refl(struct cdev *dev)
{
mtx_assert(&devmtx, MA_OWNED);
dev->si_refcount++;
}
void
dev_rel(struct cdev *dev)
{
int flag = 0;
mtx_assert(&devmtx, MA_NOTOWNED);
dev_lock();
dev->si_refcount--;
KASSERT(dev->si_refcount >= 0,
("dev_rel(%s) gave negative count", devtoname(dev)));
if (dev->si_devsw == NULL && dev->si_refcount == 0) {
LIST_REMOVE(dev, si_list);
flag = 1;
}
dev_unlock();
if (flag)
devfs_free(dev);
}
struct cdevsw *
dev_refthread(struct cdev *dev, int *ref)
{
struct cdevsw *csw;
struct cdev_priv *cdp;
mtx_assert(&devmtx, MA_NOTOWNED);
if ((dev->si_flags & SI_ETERNAL) != 0) {
*ref = 0;
return (dev->si_devsw);
}
dev_lock();
csw = dev->si_devsw;
if (csw != NULL) {
cdp = cdev2priv(dev);
if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0)
atomic_add_long(&dev->si_threadcount, 1);
else
csw = NULL;
}
dev_unlock();
if (csw != NULL)
*ref = 1;
return (csw);
}
struct cdevsw *
devvn_refthread(struct vnode *vp, struct cdev **devp, int *ref)
{
struct cdevsw *csw;
struct cdev_priv *cdp;
struct cdev *dev;
mtx_assert(&devmtx, MA_NOTOWNED);
if ((vp->v_vflag & VV_ETERNALDEV) != 0) {
dev = vp->v_rdev;
if (dev == NULL)
return (NULL);
KASSERT((dev->si_flags & SI_ETERNAL) != 0,
("Not eternal cdev"));
*ref = 0;
csw = dev->si_devsw;
KASSERT(csw != NULL, ("Eternal cdev is destroyed"));
*devp = dev;
return (csw);
}
csw = NULL;
dev_lock();
dev = vp->v_rdev;
if (dev == NULL) {
dev_unlock();
return (NULL);
}
cdp = cdev2priv(dev);
if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0) {
csw = dev->si_devsw;
if (csw != NULL)
atomic_add_long(&dev->si_threadcount, 1);
}
dev_unlock();
if (csw != NULL) {
*devp = dev;
*ref = 1;
}
return (csw);
}
void
dev_relthread(struct cdev *dev, int ref)
{
mtx_assert(&devmtx, MA_NOTOWNED);
if (!ref)
return;
KASSERT(dev->si_threadcount > 0,
("%s threadcount is wrong", dev->si_name));
atomic_subtract_rel_long(&dev->si_threadcount, 1);
}
int
nullop(void)
{
return (0);
}
int
eopnotsupp(void)
{
return (EOPNOTSUPP);
}
static int
enxio(void)
{
return (ENXIO);
}
static int
enodev(void)
{
return (ENODEV);
}
/* Define a dead_cdevsw for use when devices leave unexpectedly. */
#define dead_open (d_open_t *)enxio
#define dead_close (d_close_t *)enxio
#define dead_read (d_read_t *)enxio
#define dead_write (d_write_t *)enxio
#define dead_ioctl (d_ioctl_t *)enxio
#define dead_poll (d_poll_t *)enodev
#define dead_mmap (d_mmap_t *)enodev
static void
dead_strategy(struct bio *bp)
{
biofinish(bp, NULL, ENXIO);
}
#define dead_dump (dumper_t *)enxio
#define dead_kqfilter (d_kqfilter_t *)enxio
#define dead_mmap_single (d_mmap_single_t *)enodev
static struct cdevsw dead_cdevsw = {
.d_version = D_VERSION,
.d_open = dead_open,
.d_close = dead_close,
.d_read = dead_read,
.d_write = dead_write,
.d_ioctl = dead_ioctl,
.d_poll = dead_poll,
.d_mmap = dead_mmap,
.d_strategy = dead_strategy,
.d_name = "dead",
.d_dump = dead_dump,
.d_kqfilter = dead_kqfilter,
.d_mmap_single = dead_mmap_single
};
/* Default methods if driver does not specify method */
#define null_open (d_open_t *)nullop
#define null_close (d_close_t *)nullop
#define no_read (d_read_t *)enodev
#define no_write (d_write_t *)enodev
#define no_ioctl (d_ioctl_t *)enodev
#define no_mmap (d_mmap_t *)enodev
#define no_kqfilter (d_kqfilter_t *)enodev
#define no_mmap_single (d_mmap_single_t *)enodev
static void
no_strategy(struct bio *bp)
{
biofinish(bp, NULL, ENODEV);
}
static int
no_poll(struct cdev *dev __unused, int events, struct thread *td __unused)
{
return (poll_no_poll(events));
}
#define no_dump (dumper_t *)enodev
static int
giant_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
{
struct cdevsw *dsw;
int ref, retval;
dsw = dev_refthread(dev, &ref);
if (dsw == NULL)
return (ENXIO);
mtx_lock(&Giant);
retval = dsw->d_gianttrick->d_open(dev, oflags, devtype, td);
mtx_unlock(&Giant);
dev_relthread(dev, ref);
return (retval);
}
static int
giant_fdopen(struct cdev *dev, int oflags, struct thread *td, struct file *fp)
{
struct cdevsw *dsw;
int ref, retval;
dsw = dev_refthread(dev, &ref);
if (dsw == NULL)
return (ENXIO);
mtx_lock(&Giant);
retval = dsw->d_gianttrick->d_fdopen(dev, oflags, td, fp);
mtx_unlock(&Giant);
dev_relthread(dev, ref);
return (retval);
}
static int
giant_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
{
struct cdevsw *dsw;
int ref, retval;
dsw = dev_refthread(dev, &ref);
if (dsw == NULL)
return (ENXIO);
mtx_lock(&Giant);
retval = dsw->d_gianttrick->d_close(dev, fflag, devtype, td);
mtx_unlock(&Giant);
dev_relthread(dev, ref);
return (retval);
}
static void
giant_strategy(struct bio *bp)
{
struct cdevsw *dsw;
struct cdev *dev;
int ref;
dev = bp->bio_dev;
dsw = dev_refthread(dev, &ref);
if (dsw == NULL) {
biofinish(bp, NULL, ENXIO);
return;
}
mtx_lock(&Giant);
dsw->d_gianttrick->d_strategy(bp);
mtx_unlock(&Giant);
dev_relthread(dev, ref);
}
static int
giant_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td)
{
struct cdevsw *dsw;
int ref, retval;
dsw = dev_refthread(dev, &ref);
if (dsw == NULL)
return (ENXIO);
mtx_lock(&Giant);
retval = dsw->d_gianttrick->d_ioctl(dev, cmd, data, fflag, td);
mtx_unlock(&Giant);
dev_relthread(dev, ref);
return (retval);
}
static int
giant_read(struct cdev *dev, struct uio *uio, int ioflag)
{
struct cdevsw *dsw;
int ref, retval;
dsw = dev_refthread(dev, &ref);
if (dsw == NULL)
return (ENXIO);
mtx_lock(&Giant);
retval = dsw->d_gianttrick->d_read(dev, uio, ioflag);
mtx_unlock(&Giant);
dev_relthread(dev, ref);
return (retval);
}
static int
giant_write(struct cdev *dev, struct uio *uio, int ioflag)
{
struct cdevsw *dsw;
int ref, retval;
dsw = dev_refthread(dev, &ref);
if (dsw == NULL)
return (ENXIO);
mtx_lock(&Giant);
retval = dsw->d_gianttrick->d_write(dev, uio, ioflag);
mtx_unlock(&Giant);
dev_relthread(dev, ref);
return (retval);
}
static int
giant_poll(struct cdev *dev, int events, struct thread *td)
{
struct cdevsw *dsw;
int ref, retval;
dsw = dev_refthread(dev, &ref);
if (dsw == NULL)
return (ENXIO);
mtx_lock(&Giant);
retval = dsw->d_gianttrick->d_poll(dev, events, td);
mtx_unlock(&Giant);
dev_relthread(dev, ref);
return (retval);
}
static int
giant_kqfilter(struct cdev *dev, struct knote *kn)
{
struct cdevsw *dsw;
int ref, retval;
dsw = dev_refthread(dev, &ref);
if (dsw == NULL)
return (ENXIO);
mtx_lock(&Giant);
retval = dsw->d_gianttrick->d_kqfilter(dev, kn);
mtx_unlock(&Giant);
dev_relthread(dev, ref);
return (retval);
}
static int
giant_mmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr, int nprot,
vm_memattr_t *memattr)
{
struct cdevsw *dsw;
int ref, retval;
dsw = dev_refthread(dev, &ref);
if (dsw == NULL)
return (ENXIO);
mtx_lock(&Giant);
retval = dsw->d_gianttrick->d_mmap(dev, offset, paddr, nprot,
memattr);
mtx_unlock(&Giant);
dev_relthread(dev, ref);
return (retval);
}
static int
giant_mmap_single(struct cdev *dev, vm_ooffset_t *offset, vm_size_t size,
vm_object_t *object, int nprot)
{
struct cdevsw *dsw;
int ref, retval;
dsw = dev_refthread(dev, &ref);
if (dsw == NULL)
return (ENXIO);
mtx_lock(&Giant);
retval = dsw->d_gianttrick->d_mmap_single(dev, offset, size, object,
nprot);
mtx_unlock(&Giant);
dev_relthread(dev, ref);
return (retval);
}
static void
notify(struct cdev *dev, const char *ev, int flags)
{
static const char prefix[] = "cdev=";
char *data;
int namelen, mflags;
if (cold)
return;
mflags = (flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK;
namelen = strlen(dev->si_name);
data = malloc(namelen + sizeof(prefix), M_TEMP, mflags);
if (data == NULL)
return;
memcpy(data, prefix, sizeof(prefix) - 1);
memcpy(data + sizeof(prefix) - 1, dev->si_name, namelen + 1);
devctl_notify_f("DEVFS", "CDEV", ev, data, mflags);
free(data, M_TEMP);
}
static void
notify_create(struct cdev *dev, int flags)
{
notify(dev, "CREATE", flags);
}
static void
notify_destroy(struct cdev *dev)
{
notify(dev, "DESTROY", MAKEDEV_WAITOK);
}
static struct cdev *
newdev(struct make_dev_args *args, struct cdev *si)
{
struct cdev *si2;
struct cdevsw *csw;
mtx_assert(&devmtx, MA_OWNED);
csw = args->mda_devsw;
si2 = NULL;
if (csw->d_flags & D_NEEDMINOR) {
/* We may want to return an existing device */
LIST_FOREACH(si2, &csw->d_devs, si_list) {
if (dev2unit(si2) == args->mda_unit) {
dev_free_devlocked(si);
si = si2;
break;
}
}
/*
* If we're returning an existing device, we should make sure
* it isn't already initialized. This would have been caught
* in consumers anyways, but it's good to catch such a case
* early. We still need to complete initialization of the
* device, and we'll use whatever make_dev_args were passed in
* to do so.
*/
KASSERT(si2 == NULL || (si2->si_flags & SI_NAMED) == 0,
("make_dev() by driver %s on pre-existing device (min=%x, name=%s)",
args->mda_devsw->d_name, dev2unit(si2), devtoname(si2)));
}
si->si_drv0 = args->mda_unit;
si->si_drv1 = args->mda_si_drv1;
si->si_drv2 = args->mda_si_drv2;
/* Only push to csw->d_devs if it's not a cloned device. */
if (si2 == NULL) {
si->si_devsw = csw;
LIST_INSERT_HEAD(&csw->d_devs, si, si_list);
} else {
KASSERT(si->si_devsw == csw,
("%s: inconsistent devsw between clone_create() and make_dev()",
__func__));
}
return (si);
}
static void
fini_cdevsw(struct cdevsw *devsw)
{
struct cdevsw *gt;
if (devsw->d_gianttrick != NULL) {
gt = devsw->d_gianttrick;
memcpy(devsw, gt, sizeof *devsw);
cdevsw_free_devlocked(gt);
devsw->d_gianttrick = NULL;
}
devsw->d_flags &= ~D_INIT;
}
static int
prep_cdevsw(struct cdevsw *devsw, int flags)
{
struct cdevsw *dsw2;
mtx_assert(&devmtx, MA_OWNED);
if (devsw->d_flags & D_INIT)
return (0);
if (devsw->d_flags & D_NEEDGIANT) {
dev_unlock();
dsw2 = malloc(sizeof *dsw2, M_DEVT,
(flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK);
dev_lock();
if (dsw2 == NULL && !(devsw->d_flags & D_INIT))
return (ENOMEM);
} else
dsw2 = NULL;
if (devsw->d_flags & D_INIT) {
if (dsw2 != NULL)
cdevsw_free_devlocked(dsw2);
return (0);
}
if (devsw->d_version != D_VERSION_04) {
printf(
"WARNING: Device driver \"%s\" has wrong version %s\n",
devsw->d_name == NULL ? "???" : devsw->d_name,
"and is disabled. Recompile KLD module.");
devsw->d_open = dead_open;
devsw->d_close = dead_close;
devsw->d_read = dead_read;
devsw->d_write = dead_write;
devsw->d_ioctl = dead_ioctl;
devsw->d_poll = dead_poll;
devsw->d_mmap = dead_mmap;
devsw->d_mmap_single = dead_mmap_single;
devsw->d_strategy = dead_strategy;
devsw->d_dump = dead_dump;
devsw->d_kqfilter = dead_kqfilter;
}
if (devsw->d_flags & D_NEEDGIANT) {
if (devsw->d_gianttrick == NULL) {
memcpy(dsw2, devsw, sizeof *dsw2);
devsw->d_gianttrick = dsw2;
dsw2 = NULL;
}
}
#define FIXUP(member, noop, giant) \
do { \
if (devsw->member == NULL) { \
devsw->member = noop; \
} else if (devsw->d_flags & D_NEEDGIANT) \
devsw->member = giant; \
} \
while (0)
FIXUP(d_open, null_open, giant_open);
FIXUP(d_fdopen, NULL, giant_fdopen);
FIXUP(d_close, null_close, giant_close);
FIXUP(d_read, no_read, giant_read);
FIXUP(d_write, no_write, giant_write);
FIXUP(d_ioctl, no_ioctl, giant_ioctl);
FIXUP(d_poll, no_poll, giant_poll);
FIXUP(d_mmap, no_mmap, giant_mmap);
FIXUP(d_strategy, no_strategy, giant_strategy);
FIXUP(d_kqfilter, no_kqfilter, giant_kqfilter);
FIXUP(d_mmap_single, no_mmap_single, giant_mmap_single);
if (devsw->d_dump == NULL) devsw->d_dump = no_dump;
LIST_INIT(&devsw->d_devs);
devsw->d_flags |= D_INIT;
if (dsw2 != NULL)
cdevsw_free_devlocked(dsw2);
return (0);
}
static int
prep_devname(struct cdev *dev, const char *fmt, va_list ap)
{
int len;
char *from, *q, *s, *to;
mtx_assert(&devmtx, MA_OWNED);
len = vsnrprintf(dev->si_name, sizeof(dev->si_name), 32, fmt, ap);
if (len > sizeof(dev->si_name) - 1)
return (ENAMETOOLONG);
/* Strip leading slashes. */
for (from = dev->si_name; *from == '/'; from++)
;
for (to = dev->si_name; *from != '\0'; from++, to++) {
/*
* Spaces and double quotation marks cause
* problems for the devctl(4) protocol.
* Reject names containing those characters.
*/
if (isspace(*from) || *from == '"')
return (EINVAL);
/* Treat multiple sequential slashes as single. */
while (from[0] == '/' && from[1] == '/')
from++;
/* Trailing slash is considered invalid. */
if (from[0] == '/' && from[1] == '\0')
return (EINVAL);
*to = *from;
}
*to = '\0';
if (dev->si_name[0] == '\0')
return (EINVAL);
/* Disallow "." and ".." components. */
for (s = dev->si_name;;) {
for (q = s; *q != '/' && *q != '\0'; q++)
;
if (q - s == 1 && s[0] == '.')
return (EINVAL);
if (q - s == 2 && s[0] == '.' && s[1] == '.')
return (EINVAL);
if (*q != '/')
break;
s = q + 1;
}
if (devfs_dev_exists(dev->si_name) != 0)
return (EEXIST);
return (0);
}
void
make_dev_args_init_impl(struct make_dev_args *args, size_t sz)
{
bzero(args, sz);
args->mda_size = sz;
}
static int
make_dev_sv(struct make_dev_args *args1, struct cdev **dres,
const char *fmt, va_list ap)
{
struct cdev *dev, *dev_new;
struct make_dev_args args;
int res;
bzero(&args, sizeof(args));
if (sizeof(args) < args1->mda_size)
return (EINVAL);
bcopy(args1, &args, args1->mda_size);
KASSERT((args.mda_flags & MAKEDEV_WAITOK) == 0 ||
(args.mda_flags & MAKEDEV_NOWAIT) == 0,
("make_dev_sv: both WAITOK and NOWAIT specified"));
dev_new = devfs_alloc(args.mda_flags);
if (dev_new == NULL)
return (ENOMEM);
dev_lock();
res = prep_cdevsw(args.mda_devsw, args.mda_flags);
if (res != 0) {
dev_unlock();
devfs_free(dev_new);
return (res);
}
dev = newdev(&args, dev_new);
if ((dev->si_flags & SI_NAMED) == 0) {
res = prep_devname(dev, fmt, ap);
if (res != 0) {
if ((args.mda_flags & MAKEDEV_CHECKNAME) == 0) {
panic(
"make_dev_sv: bad si_name (error=%d, si_name=%s)",
res, dev->si_name);
}
if (dev == dev_new) {
LIST_REMOVE(dev, si_list);
dev_unlock();
devfs_free(dev);
} else
dev_unlock();
return (res);
}
}
if ((args.mda_flags & MAKEDEV_REF) != 0)
dev_refl(dev);
if ((args.mda_flags & MAKEDEV_ETERNAL) != 0)
dev->si_flags |= SI_ETERNAL;
KASSERT(!(dev->si_flags & SI_NAMED),
("make_dev() by driver %s on pre-existing device (min=%x, name=%s)",
args.mda_devsw->d_name, dev2unit(dev), devtoname(dev)));
dev->si_flags |= SI_NAMED;
if (args.mda_cr != NULL)
dev->si_cred = crhold(args.mda_cr);
dev->si_uid = args.mda_uid;
dev->si_gid = args.mda_gid;
dev->si_mode = args.mda_mode;
devfs_create(dev);
clean_unrhdrl(devfs_inos);
dev_unlock_and_free();
notify_create(dev, args.mda_flags);
*dres = dev;
return (0);
}
int
make_dev_s(struct make_dev_args *args, struct cdev **dres,
const char *fmt, ...)
{
va_list ap;
int res;
va_start(ap, fmt);
res = make_dev_sv(args, dres, fmt, ap);
va_end(ap);
return (res);
}
static int
make_dev_credv(int flags, struct cdev **dres, struct cdevsw *devsw, int unit,
struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt,
va_list ap)
{
struct make_dev_args args;
make_dev_args_init(&args);
args.mda_flags = flags;
args.mda_devsw = devsw;
args.mda_cr = cr;
args.mda_uid = uid;
args.mda_gid = gid;
args.mda_mode = mode;
args.mda_unit = unit;
return (make_dev_sv(&args, dres, fmt, ap));
}
struct cdev *
make_dev(struct cdevsw *devsw, int unit, uid_t uid, gid_t gid, int mode,
const char *fmt, ...)
{
struct cdev *dev;
va_list ap;
int res __unused;
va_start(ap, fmt);
res = make_dev_credv(0, &dev, devsw, unit, NULL, uid, gid, mode, fmt,
ap);
va_end(ap);
KASSERT(res == 0 && dev != NULL,
("make_dev: failed make_dev_credv (error=%d)", res));
return (dev);
}
struct cdev *
make_dev_cred(struct cdevsw *devsw, int unit, struct ucred *cr, uid_t uid,
gid_t gid, int mode, const char *fmt, ...)
{
struct cdev *dev;
va_list ap;
int res __unused;
va_start(ap, fmt);
res = make_dev_credv(0, &dev, devsw, unit, cr, uid, gid, mode, fmt, ap);
va_end(ap);
KASSERT(res == 0 && dev != NULL,
("make_dev_cred: failed make_dev_credv (error=%d)", res));
return (dev);
}
struct cdev *
make_dev_credf(int flags, struct cdevsw *devsw, int unit, struct ucred *cr,
uid_t uid, gid_t gid, int mode, const char *fmt, ...)
{
struct cdev *dev;
va_list ap;
int res;
va_start(ap, fmt);
res = make_dev_credv(flags, &dev, devsw, unit, cr, uid, gid, mode,
fmt, ap);
va_end(ap);
KASSERT(((flags & MAKEDEV_NOWAIT) != 0 && res == ENOMEM) ||
((flags & MAKEDEV_CHECKNAME) != 0 && res != ENOMEM) || res == 0,
("make_dev_credf: failed make_dev_credv (error=%d)", res));
return (res == 0 ? dev : NULL);
}
int
make_dev_p(int flags, struct cdev **cdev, struct cdevsw *devsw,
struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt, ...)
{
va_list ap;
int res;
va_start(ap, fmt);
res = make_dev_credv(flags, cdev, devsw, 0, cr, uid, gid, mode,
fmt, ap);
va_end(ap);
KASSERT(((flags & MAKEDEV_NOWAIT) != 0 && res == ENOMEM) ||
((flags & MAKEDEV_CHECKNAME) != 0 && res != ENOMEM) || res == 0,
("make_dev_p: failed make_dev_credv (error=%d)", res));
return (res);
}
static void
dev_dependsl(struct cdev *pdev, struct cdev *cdev)
{
cdev->si_parent = pdev;
cdev->si_flags |= SI_CHILD;
LIST_INSERT_HEAD(&pdev->si_children, cdev, si_siblings);
}
void
dev_depends(struct cdev *pdev, struct cdev *cdev)
{
dev_lock();
dev_dependsl(pdev, cdev);
dev_unlock();
}
static int
make_dev_alias_v(int flags, struct cdev **cdev, struct cdev *pdev,
const char *fmt, va_list ap)
{
struct cdev *dev;
int error;
KASSERT(pdev != NULL, ("make_dev_alias_v: pdev is NULL"));
KASSERT((flags & MAKEDEV_WAITOK) == 0 || (flags & MAKEDEV_NOWAIT) == 0,
("make_dev_alias_v: both WAITOK and NOWAIT specified"));
KASSERT((flags & ~(MAKEDEV_WAITOK | MAKEDEV_NOWAIT |
MAKEDEV_CHECKNAME)) == 0,
("make_dev_alias_v: invalid flags specified (flags=%02x)", flags));
dev = devfs_alloc(flags);
if (dev == NULL)
return (ENOMEM);
dev_lock();
dev->si_flags |= SI_ALIAS;
error = prep_devname(dev, fmt, ap);
if (error != 0) {
if ((flags & MAKEDEV_CHECKNAME) == 0) {
panic("make_dev_alias_v: bad si_name "
"(error=%d, si_name=%s)", error, dev->si_name);
}
dev_unlock();
devfs_free(dev);
return (error);
}
dev->si_flags |= SI_NAMED;
devfs_create(dev);
dev_dependsl(pdev, dev);
clean_unrhdrl(devfs_inos);
dev_unlock();
notify_create(dev, flags);
*cdev = dev;
return (0);
}
struct cdev *
make_dev_alias(struct cdev *pdev, const char *fmt, ...)
{
struct cdev *dev;
va_list ap;
int res __unused;
va_start(ap, fmt);
res = make_dev_alias_v(MAKEDEV_WAITOK, &dev, pdev, fmt, ap);
va_end(ap);
KASSERT(res == 0 && dev != NULL,
("make_dev_alias: failed make_dev_alias_v (error=%d)", res));
return (dev);
}
int
make_dev_alias_p(int flags, struct cdev **cdev, struct cdev *pdev,
const char *fmt, ...)
{
va_list ap;
int res;
va_start(ap, fmt);
res = make_dev_alias_v(flags, cdev, pdev, fmt, ap);
va_end(ap);
return (res);
}
int
make_dev_physpath_alias(int flags, struct cdev **cdev, struct cdev *pdev,
struct cdev *old_alias, const char *physpath)
{
char *devfspath;
int physpath_len;
int max_parentpath_len;
int parentpath_len;
int devfspathbuf_len;
int mflags;
int ret;
*cdev = NULL;
devfspath = NULL;
physpath_len = strlen(physpath);
ret = EINVAL;
if (physpath_len == 0)
goto out;
if (strncmp("id1,", physpath, 4) == 0) {
physpath += 4;
physpath_len -= 4;
if (physpath_len == 0)
goto out;
}
max_parentpath_len = SPECNAMELEN - physpath_len - /*/*/1;
parentpath_len = strlen(pdev->si_name);
if (max_parentpath_len < parentpath_len) {
if (bootverbose)
printf("WARNING: Unable to alias %s "
"to %s/%s - path too long\n",
pdev->si_name, physpath, pdev->si_name);
ret = ENAMETOOLONG;
goto out;
}
mflags = (flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK;
devfspathbuf_len = physpath_len + /*/*/1 + parentpath_len + /*NUL*/1;
devfspath = malloc(devfspathbuf_len, M_DEVBUF, mflags);
if (devfspath == NULL) {
ret = ENOMEM;
goto out;
}
sprintf(devfspath, "%s/%s", physpath, pdev->si_name);
if (old_alias != NULL && strcmp(old_alias->si_name, devfspath) == 0) {
/* Retain the existing alias. */
*cdev = old_alias;
old_alias = NULL;
ret = 0;
} else {
ret = make_dev_alias_p(flags, cdev, pdev, "%s", devfspath);
}
out:
if (old_alias != NULL)
destroy_dev(old_alias);
if (devfspath != NULL)
free(devfspath, M_DEVBUF);
return (ret);
}
static void
destroy_devl(struct cdev *dev)
{
struct cdevsw *csw;
struct cdev_privdata *p;
struct cdev_priv *cdp;
mtx_assert(&devmtx, MA_OWNED);
KASSERT(dev->si_flags & SI_NAMED,
("WARNING: Driver mistake: destroy_dev on %d\n", dev2unit(dev)));
KASSERT((dev->si_flags & SI_ETERNAL) == 0,
("WARNING: Driver mistake: destroy_dev on eternal %d\n",
dev2unit(dev)));
cdp = cdev2priv(dev);
if ((cdp->cdp_flags & CDP_UNREF_DTR) == 0) {
/*
* Avoid race with dev_rel(), e.g. from the populate
* loop. If CDP_UNREF_DTR flag is set, the reference
* to be dropped at the end of destroy_devl() was
* already taken by delist_dev_locked().
*/
dev_refl(dev);
devfs_destroy(dev);
}
/* Remove name marking */
dev->si_flags &= ~SI_NAMED;
/* If we are a child, remove us from the parents list */
if (dev->si_flags & SI_CHILD) {
LIST_REMOVE(dev, si_siblings);
dev->si_flags &= ~SI_CHILD;
}
/* Kill our children */
while (!LIST_EMPTY(&dev->si_children))
destroy_devl(LIST_FIRST(&dev->si_children));
/* Remove from clone list */
if (dev->si_flags & SI_CLONELIST) {
LIST_REMOVE(dev, si_clone);
dev->si_flags &= ~SI_CLONELIST;
}
csw = dev->si_devsw;
dev->si_devsw = NULL; /* already NULL for SI_ALIAS */
while (csw != NULL && csw->d_purge != NULL && dev->si_threadcount) {
csw->d_purge(dev);
msleep(csw, &devmtx, PRIBIO, "devprg", hz/10);
if (dev->si_threadcount)
printf("Still %lu threads in %s\n",
dev->si_threadcount, devtoname(dev));
}
while (dev->si_threadcount != 0) {
/* Use unique dummy wait ident */
msleep(&csw, &devmtx, PRIBIO, "devdrn", hz / 10);
}
dev_unlock();
if ((cdp->cdp_flags & CDP_UNREF_DTR) == 0) {
/* avoid out of order notify events */
notify_destroy(dev);
}
mtx_lock(&cdevpriv_mtx);
while ((p = LIST_FIRST(&cdp->cdp_fdpriv)) != NULL) {
devfs_destroy_cdevpriv(p);
mtx_lock(&cdevpriv_mtx);
}
mtx_unlock(&cdevpriv_mtx);
dev_lock();
dev->si_drv1 = 0;
dev->si_drv2 = 0;
bzero(&dev->__si_u, sizeof(dev->__si_u));
if (!(dev->si_flags & SI_ALIAS)) {
/* Remove from cdevsw list */
LIST_REMOVE(dev, si_list);
/* If cdevsw has no more struct cdev *'s, clean it */
if (LIST_EMPTY(&csw->d_devs)) {
fini_cdevsw(csw);
wakeup(&csw->d_devs);
}
}
dev->si_flags &= ~SI_ALIAS;
cdp->cdp_flags &= ~CDP_UNREF_DTR;
dev->si_refcount--;
if (dev->si_refcount > 0)
LIST_INSERT_HEAD(&dead_cdevsw.d_devs, dev, si_list);
else
dev_free_devlocked(dev);
}
static void
delist_dev_locked(struct cdev *dev)
{
struct cdev_priv *cdp;
struct cdev *child;
mtx_assert(&devmtx, MA_OWNED);
cdp = cdev2priv(dev);
if ((cdp->cdp_flags & CDP_UNREF_DTR) != 0)
return;
cdp->cdp_flags |= CDP_UNREF_DTR;
dev_refl(dev);
devfs_destroy(dev);
LIST_FOREACH(child, &dev->si_children, si_siblings)
delist_dev_locked(child);
dev_unlock();
/* ensure the destroy event is queued in order */
notify_destroy(dev);
dev_lock();
}
/*
* This function will delist a character device and its children from
* the directory listing and create a destroy event without waiting
* for all character device references to go away. At some later point
* destroy_dev() must be called to complete the character device
* destruction. After calling this function the character device name
* can instantly be re-used.
*/
void
delist_dev(struct cdev *dev)
{
WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "delist_dev");
dev_lock();
delist_dev_locked(dev);
dev_unlock();
}
void
destroy_dev(struct cdev *dev)
{
WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "destroy_dev");
dev_lock();
destroy_devl(dev);
dev_unlock_and_free();
}
const char *
devtoname(struct cdev *dev)
{
return (dev->si_name);
}
int
dev_stdclone(char *name, char **namep, const char *stem, int *unit)
{
int u, i;
i = strlen(stem);
if (bcmp(stem, name, i) != 0)
return (0);
if (!isdigit(name[i]))
return (0);
u = 0;
if (name[i] == '0' && isdigit(name[i+1]))
return (0);
while (isdigit(name[i])) {
u *= 10;
u += name[i++] - '0';
}
if (u > 0xffffff)
return (0);
*unit = u;
if (namep)
*namep = &name[i];
if (name[i])
return (2);
return (1);
}
/*
* Helper functions for cloning device drivers.
*
* The objective here is to make it unnecessary for the device drivers to
* use rman or similar to manage their unit number space. Due to the way
* we do "on-demand" devices, using rman or other "private" methods
* will be very tricky to lock down properly once we lock down this file.
*
* Instead we give the drivers these routines which puts the struct cdev *'s
* that are to be managed on their own list, and gives the driver the ability
* to ask for the first free unit number or a given specified unit number.
*
* In addition these routines support paired devices (pty, nmdm and similar)
* by respecting a number of "flag" bits in the minor number.
*
*/
struct clonedevs {
LIST_HEAD(,cdev) head;
};
void
clone_setup(struct clonedevs **cdp)
{
*cdp = malloc(sizeof **cdp, M_DEVBUF, M_WAITOK | M_ZERO);
LIST_INIT(&(*cdp)->head);
}
int
clone_create(struct clonedevs **cdp, struct cdevsw *csw, int *up,
struct cdev **dp, int extra)
{
struct clonedevs *cd;
struct cdev *dev, *ndev, *dl, *de;
struct make_dev_args args;
int unit, low, u;
KASSERT(*cdp != NULL,
("clone_setup() not called in driver \"%s\"", csw->d_name));
KASSERT(!(extra & CLONE_UNITMASK),
("Illegal extra bits (0x%x) in clone_create", extra));
KASSERT(*up <= CLONE_UNITMASK,
("Too high unit (0x%x) in clone_create", *up));
KASSERT(csw->d_flags & D_NEEDMINOR,
("clone_create() on cdevsw without minor numbers"));
/*
* Search the list for a lot of things in one go:
* A preexisting match is returned immediately.
* The lowest free unit number if we are passed -1, and the place
* in the list where we should insert that new element.
* The place to insert a specified unit number, if applicable
* the end of the list.
*/
unit = *up;
ndev = devfs_alloc(MAKEDEV_WAITOK);
dev_lock();
prep_cdevsw(csw, MAKEDEV_WAITOK);
low = extra;
de = dl = NULL;
cd = *cdp;
LIST_FOREACH(dev, &cd->head, si_clone) {
KASSERT(dev->si_flags & SI_CLONELIST,
("Dev %p(%s) should be on clonelist", dev, dev->si_name));
u = dev2unit(dev);
if (u == (unit | extra)) {
*dp = dev;
dev_unlock();
devfs_free(ndev);
return (0);
}
if (unit == -1 && u == low) {
low++;
de = dev;
continue;
} else if (u < (unit | extra)) {
de = dev;
continue;
} else if (u > (unit | extra)) {
dl = dev;
break;
}
}
if (unit == -1)
unit = low & CLONE_UNITMASK;
make_dev_args_init(&args);
args.mda_unit = unit | extra;
args.mda_devsw = csw;
dev = newdev(&args, ndev);
if (dev->si_flags & SI_CLONELIST) {
printf("dev %p (%s) is on clonelist\n", dev, dev->si_name);
printf("unit=%d, low=%d, extra=0x%x\n", unit, low, extra);
LIST_FOREACH(dev, &cd->head, si_clone) {
printf("\t%p %s\n", dev, dev->si_name);
}
panic("foo");
}
KASSERT(!(dev->si_flags & SI_CLONELIST),
("Dev %p(%s) should not be on clonelist", dev, dev->si_name));
if (dl != NULL)
LIST_INSERT_BEFORE(dl, dev, si_clone);
else if (de != NULL)
LIST_INSERT_AFTER(de, dev, si_clone);
else
LIST_INSERT_HEAD(&cd->head, dev, si_clone);
dev->si_flags |= SI_CLONELIST;
*up = unit;
dev_unlock_and_free();
return (1);
}
/*
* Kill everything still on the list. The driver should already have
* disposed of any softc hung of the struct cdev *'s at this time.
*/
void
clone_cleanup(struct clonedevs **cdp)
{
struct cdev *dev;
struct cdev_priv *cp;
struct clonedevs *cd;
cd = *cdp;
if (cd == NULL)
return;
dev_lock();
while (!LIST_EMPTY(&cd->head)) {
dev = LIST_FIRST(&cd->head);
LIST_REMOVE(dev, si_clone);
KASSERT(dev->si_flags & SI_CLONELIST,
("Dev %p(%s) should be on clonelist", dev, dev->si_name));
dev->si_flags &= ~SI_CLONELIST;
cp = cdev2priv(dev);
if (!(cp->cdp_flags & CDP_SCHED_DTR)) {
cp->cdp_flags |= CDP_SCHED_DTR;
KASSERT(dev->si_flags & SI_NAMED,
("Driver has goofed in cloning underways udev %jx unit %x",
(uintmax_t)dev2udev(dev), dev2unit(dev)));
destroy_devl(dev);
}
}
dev_unlock_and_free();
free(cd, M_DEVBUF);
*cdp = NULL;
}
static TAILQ_HEAD(, cdev_priv) dev_ddtr =
TAILQ_HEAD_INITIALIZER(dev_ddtr);
static struct task dev_dtr_task = TASK_INITIALIZER(0, destroy_dev_tq, NULL);
static void
destroy_dev_tq(void *ctx, int pending)
{
struct cdev_priv *cp;
struct cdev *dev;
void (*cb)(void *);
void *cb_arg;
dev_lock();
while (!TAILQ_EMPTY(&dev_ddtr)) {
cp = TAILQ_FIRST(&dev_ddtr);
dev = &cp->cdp_c;
KASSERT(cp->cdp_flags & CDP_SCHED_DTR,
("cdev %p in dev_destroy_tq without CDP_SCHED_DTR", cp));
TAILQ_REMOVE(&dev_ddtr, cp, cdp_dtr_list);
cb = cp->cdp_dtr_cb;
cb_arg = cp->cdp_dtr_cb_arg;
destroy_devl(dev);
dev_unlock_and_free();
dev_rel(dev);
if (cb != NULL)
cb(cb_arg);
dev_lock();
}
dev_unlock();
}
/*
* devmtx shall be locked on entry. devmtx will be unlocked after
* function return.
*/
static int
destroy_dev_sched_cbl(struct cdev *dev, void (*cb)(void *), void *arg)
{
struct cdev_priv *cp;
mtx_assert(&devmtx, MA_OWNED);
cp = cdev2priv(dev);
if (cp->cdp_flags & CDP_SCHED_DTR) {
dev_unlock();
return (0);
}
dev_refl(dev);
cp->cdp_flags |= CDP_SCHED_DTR;
cp->cdp_dtr_cb = cb;
cp->cdp_dtr_cb_arg = arg;
TAILQ_INSERT_TAIL(&dev_ddtr, cp, cdp_dtr_list);
dev_unlock();
taskqueue_enqueue(taskqueue_swi_giant, &dev_dtr_task);
return (1);
}
int
destroy_dev_sched_cb(struct cdev *dev, void (*cb)(void *), void *arg)
{
dev_lock();
return (destroy_dev_sched_cbl(dev, cb, arg));
}
int
destroy_dev_sched(struct cdev *dev)
{
return (destroy_dev_sched_cb(dev, NULL, NULL));
}
void
destroy_dev_drain(struct cdevsw *csw)
{
dev_lock();
while (!LIST_EMPTY(&csw->d_devs)) {
msleep(&csw->d_devs, &devmtx, PRIBIO, "devscd", hz/10);
}
dev_unlock();
}
void
drain_dev_clone_events(void)
{
sx_xlock(&clone_drain_lock);
sx_xunlock(&clone_drain_lock);
}
#include "opt_ddb.h"
#ifdef DDB
#include <sys/kernel.h>
#include <ddb/ddb.h>
DB_SHOW_COMMAND(cdev, db_show_cdev)
{
struct cdev_priv *cdp;
struct cdev *dev;
u_int flags;
char buf[512];
if (!have_addr) {
TAILQ_FOREACH(cdp, &cdevp_list, cdp_list) {
dev = &cdp->cdp_c;
db_printf("%s %p\n", dev->si_name, dev);
if (db_pager_quit)
break;
}
return;
}
dev = (struct cdev *)addr;
cdp = cdev2priv(dev);
db_printf("dev %s ref %d use %ld thr %ld inuse %u fdpriv %p\n",
dev->si_name, dev->si_refcount, dev->si_usecount,
dev->si_threadcount, cdp->cdp_inuse, cdp->cdp_fdpriv.lh_first);
db_printf("devsw %p si_drv0 %d si_drv1 %p si_drv2 %p\n",
dev->si_devsw, dev->si_drv0, dev->si_drv1, dev->si_drv2);
flags = dev->si_flags;
#define SI_FLAG(flag) do { \
if (flags & (flag)) { \
if (buf[0] != '\0') \
strlcat(buf, ", ", sizeof(buf)); \
strlcat(buf, (#flag) + 3, sizeof(buf)); \
flags &= ~(flag); \
} \
} while (0)
buf[0] = '\0';
SI_FLAG(SI_ETERNAL);
SI_FLAG(SI_ALIAS);
SI_FLAG(SI_NAMED);
SI_FLAG(SI_CHILD);
SI_FLAG(SI_DUMPDEV);
SI_FLAG(SI_CLONELIST);
db_printf("si_flags %s\n", buf);
flags = cdp->cdp_flags;
#define CDP_FLAG(flag) do { \
if (flags & (flag)) { \
if (buf[0] != '\0') \
strlcat(buf, ", ", sizeof(buf)); \
strlcat(buf, (#flag) + 4, sizeof(buf)); \
flags &= ~(flag); \
} \
} while (0)
buf[0] = '\0';
CDP_FLAG(CDP_ACTIVE);
CDP_FLAG(CDP_SCHED_DTR);
db_printf("cdp_flags %s\n", buf);
}
#endif
Reference in New Issue View Git Blame Copy Permalink