freebsd-skq/sys/dev/sound/pcm/sndstat.c
pho 289be1b82d Added D_TRACKCLOSE to sndstat_cdevsw to fix the situation when
another process is in open() or stat() for the device node, then
close() from the owning process does not result in cdevsw close
method call. This fixes the pemanent "Device busy" seen.

Changed the sndstat_lock from mutex to sx.  This allows to extend
the region covered by the lock, to include the uiomove() call in
sndstat_read() and bufptr increment. This fixes the "panic:
sbuf_put_byte called with finished or corrupt sbuf" seen.

In collaboration with:	kib
MFC after:	1 week
2012-05-02 19:32:11 +00:00

443 lines
10 KiB
C

/*-
* Copyright (c) 2005-2009 Ariff Abdullah <ariff@FreeBSD.org>
* Copyright (c) 2001 Cameron Grant <cg@FreeBSD.org>
* 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.
*/
#ifdef HAVE_KERNEL_OPTION_HEADERS
#include "opt_snd.h"
#endif
#include <dev/sound/pcm/sound.h>
#include <dev/sound/pcm/pcm.h>
#include <dev/sound/version.h>
#include <sys/sx.h>
SND_DECLARE_FILE("$FreeBSD$");
#define SS_TYPE_MODULE 0
#define SS_TYPE_FIRST 1
#define SS_TYPE_PCM 1
#define SS_TYPE_MIDI 2
#define SS_TYPE_SEQUENCER 3
#define SS_TYPE_LAST 3
static d_open_t sndstat_open;
static d_close_t sndstat_close;
static d_read_t sndstat_read;
static struct cdevsw sndstat_cdevsw = {
.d_version = D_VERSION,
.d_open = sndstat_open,
.d_close = sndstat_close,
.d_read = sndstat_read,
.d_name = "sndstat",
.d_flags = D_TRACKCLOSE,
};
struct sndstat_entry {
SLIST_ENTRY(sndstat_entry) link;
device_t dev;
char *str;
sndstat_handler handler;
int type, unit;
};
static struct sx sndstat_lock;
static struct sbuf sndstat_sbuf;
static struct cdev *sndstat_dev = NULL;
static int sndstat_bufptr = -1;
static int sndstat_maxunit = -1;
static int sndstat_files = 0;
#define SNDSTAT_PID(x) ((pid_t)((intptr_t)((x)->si_drv1)))
#define SNDSTAT_PID_SET(x, y) (x)->si_drv1 = (void *)((intptr_t)(y))
#define SNDSTAT_FLUSH() do { \
if (sndstat_bufptr != -1) { \
sbuf_delete(&sndstat_sbuf); \
sndstat_bufptr = -1; \
} \
} while (0)
static SLIST_HEAD(, sndstat_entry) sndstat_devlist = SLIST_HEAD_INITIALIZER(sndstat_devlist);
int snd_verbose = 0;
TUNABLE_INT("hw.snd.verbose", &snd_verbose);
#ifdef SND_DEBUG
static int
sysctl_hw_snd_sndstat_pid(SYSCTL_HANDLER_ARGS)
{
int err, val;
if (sndstat_dev == NULL)
return (EINVAL);
sx_xlock(&sndstat_lock);
val = (int)SNDSTAT_PID(sndstat_dev);
err = sysctl_handle_int(oidp, &val, 0, req);
if (err == 0 && req->newptr != NULL && val == 0) {
SNDSTAT_FLUSH();
SNDSTAT_PID_SET(sndstat_dev, 0);
}
sx_unlock(&sndstat_lock);
return (err);
}
SYSCTL_PROC(_hw_snd, OID_AUTO, sndstat_pid, CTLTYPE_INT | CTLFLAG_RW,
0, sizeof(int), sysctl_hw_snd_sndstat_pid, "I", "sndstat busy pid");
#endif
static int sndstat_prepare(struct sbuf *s);
static int
sysctl_hw_sndverbose(SYSCTL_HANDLER_ARGS)
{
int error, verbose;
verbose = snd_verbose;
error = sysctl_handle_int(oidp, &verbose, 0, req);
if (error == 0 && req->newptr != NULL) {
if (verbose < 0 || verbose > 4)
error = EINVAL;
else
snd_verbose = verbose;
}
return error;
}
SYSCTL_PROC(_hw_snd, OID_AUTO, verbose, CTLTYPE_INT | CTLFLAG_RW,
0, sizeof(int), sysctl_hw_sndverbose, "I", "verbosity level");
static int
sndstat_open(struct cdev *i_dev, int flags, int mode, struct thread *td)
{
if (sndstat_dev == NULL || i_dev != sndstat_dev)
return EBADF;
sx_xlock(&sndstat_lock);
if (SNDSTAT_PID(i_dev) != 0) {
sx_unlock(&sndstat_lock);
return EBUSY;
}
SNDSTAT_PID_SET(i_dev, td->td_proc->p_pid);
if (sbuf_new(&sndstat_sbuf, NULL, 4096, SBUF_AUTOEXTEND) == NULL) {
SNDSTAT_PID_SET(i_dev, 0);
sx_unlock(&sndstat_lock);
return ENXIO;
}
sndstat_bufptr = 0;
sx_unlock(&sndstat_lock);
return 0;
}
static int
sndstat_close(struct cdev *i_dev, int flags, int mode, struct thread *td)
{
if (sndstat_dev == NULL || i_dev != sndstat_dev)
return EBADF;
sx_xlock(&sndstat_lock);
if (SNDSTAT_PID(i_dev) == 0) {
sx_unlock(&sndstat_lock);
return EBADF;
}
SNDSTAT_FLUSH();
SNDSTAT_PID_SET(i_dev, 0);
sx_unlock(&sndstat_lock);
return 0;
}
static int
sndstat_read(struct cdev *i_dev, struct uio *buf, int flag)
{
int l, err;
if (sndstat_dev == NULL || i_dev != sndstat_dev)
return EBADF;
sx_xlock(&sndstat_lock);
if (SNDSTAT_PID(i_dev) != buf->uio_td->td_proc->p_pid ||
sndstat_bufptr == -1) {
sx_unlock(&sndstat_lock);
return EBADF;
}
if (sndstat_bufptr == 0) {
err = (sndstat_prepare(&sndstat_sbuf) > 0) ? 0 : ENOMEM;
if (err) {
SNDSTAT_FLUSH();
sx_unlock(&sndstat_lock);
return err;
}
}
l = min(buf->uio_resid, sbuf_len(&sndstat_sbuf) - sndstat_bufptr);
err = (l > 0)? uiomove(sbuf_data(&sndstat_sbuf) + sndstat_bufptr, l, buf) : 0;
sndstat_bufptr += l;
sx_unlock(&sndstat_lock);
return err;
}
/************************************************************************/
static struct sndstat_entry *
sndstat_find(int type, int unit)
{
struct sndstat_entry *ent;
SLIST_FOREACH(ent, &sndstat_devlist, link) {
if (ent->type == type && ent->unit == unit)
return ent;
}
return NULL;
}
int
sndstat_acquire(struct thread *td)
{
if (sndstat_dev == NULL)
return EBADF;
sx_xlock(&sndstat_lock);
if (SNDSTAT_PID(sndstat_dev) != 0) {
sx_unlock(&sndstat_lock);
return EBUSY;
}
SNDSTAT_PID_SET(sndstat_dev, td->td_proc->p_pid);
sx_unlock(&sndstat_lock);
return 0;
}
int
sndstat_release(struct thread *td)
{
if (sndstat_dev == NULL)
return EBADF;
sx_xlock(&sndstat_lock);
if (SNDSTAT_PID(sndstat_dev) != td->td_proc->p_pid) {
sx_unlock(&sndstat_lock);
return EBADF;
}
SNDSTAT_PID_SET(sndstat_dev, 0);
sx_unlock(&sndstat_lock);
return 0;
}
int
sndstat_register(device_t dev, char *str, sndstat_handler handler)
{
struct sndstat_entry *ent;
const char *devtype;
int type, unit;
if (dev) {
unit = device_get_unit(dev);
devtype = device_get_name(dev);
if (!strcmp(devtype, "pcm"))
type = SS_TYPE_PCM;
else if (!strcmp(devtype, "midi"))
type = SS_TYPE_MIDI;
else if (!strcmp(devtype, "sequencer"))
type = SS_TYPE_SEQUENCER;
else
return EINVAL;
} else {
type = SS_TYPE_MODULE;
unit = -1;
}
ent = malloc(sizeof *ent, M_DEVBUF, M_WAITOK | M_ZERO);
ent->dev = dev;
ent->str = str;
ent->type = type;
ent->unit = unit;
ent->handler = handler;
sx_xlock(&sndstat_lock);
SLIST_INSERT_HEAD(&sndstat_devlist, ent, link);
if (type == SS_TYPE_MODULE)
sndstat_files++;
sndstat_maxunit = (unit > sndstat_maxunit)? unit : sndstat_maxunit;
sx_unlock(&sndstat_lock);
return 0;
}
int
sndstat_registerfile(char *str)
{
return sndstat_register(NULL, str, NULL);
}
int
sndstat_unregister(device_t dev)
{
struct sndstat_entry *ent;
sx_xlock(&sndstat_lock);
SLIST_FOREACH(ent, &sndstat_devlist, link) {
if (ent->dev == dev) {
SLIST_REMOVE(&sndstat_devlist, ent, sndstat_entry, link);
sx_unlock(&sndstat_lock);
free(ent, M_DEVBUF);
return 0;
}
}
sx_unlock(&sndstat_lock);
return ENXIO;
}
int
sndstat_unregisterfile(char *str)
{
struct sndstat_entry *ent;
sx_xlock(&sndstat_lock);
SLIST_FOREACH(ent, &sndstat_devlist, link) {
if (ent->dev == NULL && ent->str == str) {
SLIST_REMOVE(&sndstat_devlist, ent, sndstat_entry, link);
sndstat_files--;
sx_unlock(&sndstat_lock);
free(ent, M_DEVBUF);
return 0;
}
}
sx_unlock(&sndstat_lock);
return ENXIO;
}
/************************************************************************/
static int
sndstat_prepare(struct sbuf *s)
{
struct sndstat_entry *ent;
struct snddev_info *d;
int i, j;
sbuf_printf(s, "FreeBSD Audio Driver (newpcm: %ubit %d/%s)\n",
(u_int)sizeof(intpcm32_t) << 3, SND_DRV_VERSION, MACHINE_ARCH);
if (SLIST_EMPTY(&sndstat_devlist)) {
sbuf_printf(s, "No devices installed.\n");
sbuf_finish(s);
return sbuf_len(s);
}
sbuf_printf(s, "Installed devices:\n");
for (i = 0; i <= sndstat_maxunit; i++) {
for (j = SS_TYPE_FIRST; j <= SS_TYPE_LAST; j++) {
ent = sndstat_find(j, i);
if (!ent)
continue;
d = device_get_softc(ent->dev);
if (!PCM_REGISTERED(d))
continue;
/* XXX Need Giant magic entry ??? */
PCM_ACQUIRE_QUICK(d);
sbuf_printf(s, "%s:", device_get_nameunit(ent->dev));
sbuf_printf(s, " <%s>", device_get_desc(ent->dev));
if (snd_verbose > 0)
sbuf_printf(s, " %s", ent->str);
if (ent->handler)
ent->handler(s, ent->dev, snd_verbose);
sbuf_printf(s, "\n");
PCM_RELEASE_QUICK(d);
}
}
if (snd_verbose >= 3 && sndstat_files > 0) {
sbuf_printf(s, "\nFile Versions:\n");
SLIST_FOREACH(ent, &sndstat_devlist, link) {
if (ent->dev == NULL && ent->str != NULL)
sbuf_printf(s, "%s\n", ent->str);
}
}
sbuf_finish(s);
return sbuf_len(s);
}
static int
sndstat_init(void)
{
if (sndstat_dev != NULL)
return EINVAL;
sx_init(&sndstat_lock, "sndstat lock");
sndstat_dev = make_dev(&sndstat_cdevsw, SND_DEV_STATUS,
UID_ROOT, GID_WHEEL, 0444, "sndstat");
return 0;
}
static int
sndstat_uninit(void)
{
if (sndstat_dev == NULL)
return EINVAL;
sx_xlock(&sndstat_lock);
if (SNDSTAT_PID(sndstat_dev) != curthread->td_proc->p_pid) {
sx_unlock(&sndstat_lock);
return EBUSY;
}
/* XXXPHO: use destroy_dev_sched() */
destroy_dev(sndstat_dev);
sndstat_dev = NULL;
SNDSTAT_FLUSH();
sx_unlock(&sndstat_lock);
sx_destroy(&sndstat_lock);
return 0;
}
static void
sndstat_sysinit(void *p)
{
sndstat_init();
}
static void
sndstat_sysuninit(void *p)
{
int error;
error = sndstat_uninit();
KASSERT(error == 0, ("%s: error = %d", __func__, error));
}
SYSINIT(sndstat_sysinit, SI_SUB_DRIVERS, SI_ORDER_FIRST, sndstat_sysinit, NULL);
SYSUNINIT(sndstat_sysuninit, SI_SUB_DRIVERS, SI_ORDER_FIRST, sndstat_sysuninit, NULL);