freebsd-dev/sys/kern/tty_cons.c
Attilio Rao 22db15c06f VOP_LOCK1() (and so VOP_LOCK()) and VOP_UNLOCK() are only used in
conjuction with 'thread' argument passing which is always curthread.
Remove the unuseful extra-argument and pass explicitly curthread to lower
layer functions, when necessary.

KPI results broken by this change, which should affect several ports, so
version bumping and manpage update will be further committed.

Tested by: kris, pho, Diego Sardina <siarodx at gmail dot com>
2008-01-13 14:44:15 +00:00

735 lines
16 KiB
C

/*-
* Copyright (c) 1988 University of Utah.
* Copyright (c) 1991 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* the Systems Programming Group of the University of Utah Computer
* Science Department.
*
* 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.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*
* from: @(#)cons.c 7.2 (Berkeley) 5/9/91
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_ddb.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/conf.h>
#include <sys/cons.h>
#include <sys/fcntl.h>
#include <sys/kdb.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/msgbuf.h>
#include <sys/namei.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/queue.h>
#include <sys/reboot.h>
#include <sys/sysctl.h>
#include <sys/sbuf.h>
#include <sys/tty.h>
#include <sys/uio.h>
#include <sys/vnode.h>
#include <ddb/ddb.h>
#include <machine/cpu.h>
static d_open_t cnopen;
static d_close_t cnclose;
static d_read_t cnread;
static d_write_t cnwrite;
static d_ioctl_t cnioctl;
static d_poll_t cnpoll;
static d_kqfilter_t cnkqfilter;
static struct cdevsw cn_cdevsw = {
.d_version = D_VERSION,
.d_open = cnopen,
.d_close = cnclose,
.d_read = cnread,
.d_write = cnwrite,
.d_ioctl = cnioctl,
.d_poll = cnpoll,
.d_name = "console",
.d_flags = D_TTY | D_NEEDGIANT,
.d_kqfilter = cnkqfilter,
};
struct cn_device {
STAILQ_ENTRY(cn_device) cnd_next;
struct vnode *cnd_vp;
struct consdev *cnd_cn;
};
#define CNDEVPATHMAX 32
#define CNDEVTAB_SIZE 4
static struct cn_device cn_devtab[CNDEVTAB_SIZE];
static STAILQ_HEAD(, cn_device) cn_devlist =
STAILQ_HEAD_INITIALIZER(cn_devlist);
#define CND_INVALID(cnd, td) \
(cnd == NULL || cnd->cnd_vp == NULL || \
(cnd->cnd_vp->v_type == VBAD && !cn_devopen(cnd, td, 1)))
static dev_t cn_udev_t;
SYSCTL_OPAQUE(_machdep, OID_AUTO, consdev, CTLFLAG_RD,
&cn_udev_t, sizeof cn_udev_t, "T,struct cdev *", "");
int cons_avail_mask = 0; /* Bit mask. Each registered low level console
* which is currently unavailable for inpit
* (i.e., if it is in graphics mode) will have
* this bit cleared.
*/
static int cn_mute;
static int openflag; /* how /dev/console was opened */
static int cn_is_open;
static char *consbuf; /* buffer used by `consmsgbuf' */
static struct callout conscallout; /* callout for outputting to constty */
struct msgbuf consmsgbuf; /* message buffer for console tty */
static u_char console_pausing; /* pause after each line during probe */
static char *console_pausestr=
"<pause; press any key to proceed to next line or '.' to end pause mode>";
struct tty *constty; /* pointer to console "window" tty */
static struct mtx cnputs_mtx; /* Mutex for cnputs(). */
static int use_cnputs_mtx = 0; /* != 0 if cnputs_mtx locking reqd. */
static void constty_timeout(void *arg);
static struct consdev cons_consdev;
DATA_SET(cons_set, cons_consdev);
SET_DECLARE(cons_set, struct consdev);
void
cninit(void)
{
struct consdev *best_cn, *cn, **list;
/*
* Check if we should mute the console (for security reasons perhaps)
* It can be changes dynamically using sysctl kern.consmute
* once we are up and going.
*
*/
cn_mute = ((boothowto & (RB_MUTE
|RB_SINGLE
|RB_VERBOSE
|RB_ASKNAME)) == RB_MUTE);
/*
* Find the first console with the highest priority.
*/
best_cn = NULL;
SET_FOREACH(list, cons_set) {
cn = *list;
cnremove(cn);
if (cn->cn_probe == NULL)
continue;
cn->cn_probe(cn);
if (cn->cn_pri == CN_DEAD)
continue;
if (best_cn == NULL || cn->cn_pri > best_cn->cn_pri)
best_cn = cn;
if (boothowto & RB_MULTIPLE) {
/*
* Initialize console, and attach to it.
*/
cn->cn_init(cn);
cnadd(cn);
}
}
if (best_cn == NULL)
return;
if ((boothowto & RB_MULTIPLE) == 0) {
best_cn->cn_init(best_cn);
cnadd(best_cn);
}
if (boothowto & RB_PAUSE)
console_pausing = 1;
/*
* Make the best console the preferred console.
*/
cnselect(best_cn);
}
void
cninit_finish()
{
console_pausing = 0;
}
/* add a new physical console to back the virtual console */
int
cnadd(struct consdev *cn)
{
struct cn_device *cnd;
int i;
STAILQ_FOREACH(cnd, &cn_devlist, cnd_next)
if (cnd->cnd_cn == cn)
return (0);
for (i = 0; i < CNDEVTAB_SIZE; i++) {
cnd = &cn_devtab[i];
if (cnd->cnd_cn == NULL)
break;
}
if (cnd->cnd_cn != NULL)
return (ENOMEM);
cnd->cnd_cn = cn;
if (cn->cn_name[0] == '\0') {
/* XXX: it is unclear if/where this print might output */
printf("WARNING: console at %p has no name\n", cn);
}
STAILQ_INSERT_TAIL(&cn_devlist, cnd, cnd_next);
/* Add device to the active mask. */
cnavailable(cn, (cn->cn_flags & CN_FLAG_NOAVAIL) == 0);
return (0);
}
void
cnremove(struct consdev *cn)
{
struct cn_device *cnd;
int i;
STAILQ_FOREACH(cnd, &cn_devlist, cnd_next) {
if (cnd->cnd_cn != cn)
continue;
STAILQ_REMOVE(&cn_devlist, cnd, cn_device, cnd_next);
if (cnd->cnd_vp != NULL)
vn_close(cnd->cnd_vp, openflag, NOCRED, NULL);
cnd->cnd_vp = NULL;
cnd->cnd_cn = NULL;
/* Remove this device from available mask. */
for (i = 0; i < CNDEVTAB_SIZE; i++)
if (cnd == &cn_devtab[i]) {
cons_avail_mask &= ~(1 << i);
break;
}
#if 0
/*
* XXX
* syscons gets really confused if console resources are
* freed after the system has initialized.
*/
if (cn->cn_term != NULL)
cn->cn_term(cn);
#endif
return;
}
}
void
cnselect(struct consdev *cn)
{
struct cn_device *cnd;
STAILQ_FOREACH(cnd, &cn_devlist, cnd_next) {
if (cnd->cnd_cn != cn)
continue;
if (cnd == STAILQ_FIRST(&cn_devlist))
return;
STAILQ_REMOVE(&cn_devlist, cnd, cn_device, cnd_next);
STAILQ_INSERT_HEAD(&cn_devlist, cnd, cnd_next);
return;
}
}
void
cnavailable(struct consdev *cn, int available)
{
int i;
for (i = 0; i < CNDEVTAB_SIZE; i++) {
if (cn_devtab[i].cnd_cn == cn)
break;
}
if (available) {
if (i < CNDEVTAB_SIZE)
cons_avail_mask |= (1 << i);
cn->cn_flags &= ~CN_FLAG_NOAVAIL;
} else {
if (i < CNDEVTAB_SIZE)
cons_avail_mask &= ~(1 << i);
cn->cn_flags |= CN_FLAG_NOAVAIL;
}
}
int
cnunavailable(void)
{
return (cons_avail_mask == 0);
}
/*
* sysctl_kern_console() provides output parseable in conscontrol(1).
*/
static int
sysctl_kern_console(SYSCTL_HANDLER_ARGS)
{
struct cn_device *cnd;
struct consdev *cp, **list;
char *p;
int delete, error;
struct sbuf *sb;
sb = sbuf_new(NULL, NULL, CNDEVPATHMAX * 2, SBUF_AUTOEXTEND);
if (sb == NULL)
return (ENOMEM);
sbuf_clear(sb);
STAILQ_FOREACH(cnd, &cn_devlist, cnd_next)
sbuf_printf(sb, "%s,", cnd->cnd_cn->cn_name);
sbuf_printf(sb, "/");
SET_FOREACH(list, cons_set) {
cp = *list;
if (cp->cn_name[0] != '\0')
sbuf_printf(sb, "%s,", cp->cn_name);
}
sbuf_finish(sb);
error = sysctl_handle_string(oidp, sbuf_data(sb), sbuf_len(sb), req);
if (error == 0 && req->newptr != NULL) {
p = sbuf_data(sb);
error = ENXIO;
delete = 0;
if (*p == '-') {
delete = 1;
p++;
}
SET_FOREACH(list, cons_set) {
cp = *list;
if (strcmp(p, cp->cn_name) != 0)
continue;
if (delete) {
cnremove(cp);
error = 0;
} else {
error = cnadd(cp);
if (error == 0)
cnselect(cp);
}
break;
}
}
sbuf_delete(sb);
return (error);
}
SYSCTL_PROC(_kern, OID_AUTO, console, CTLTYPE_STRING|CTLFLAG_RW,
0, 0, sysctl_kern_console, "A", "Console device control");
/*
* User has changed the state of the console muting.
* This may require us to open or close the device in question.
*/
static int
sysctl_kern_consmute(SYSCTL_HANDLER_ARGS)
{
int error;
int ocn_mute;
ocn_mute = cn_mute;
error = sysctl_handle_int(oidp, &cn_mute, 0, req);
if (error != 0 || req->newptr == NULL)
return (error);
if (ocn_mute && !cn_mute && cn_is_open)
error = cnopen(NULL, openflag, 0, curthread);
else if (!ocn_mute && cn_mute && cn_is_open) {
error = cnclose(NULL, openflag, 0, curthread);
cn_is_open = 1; /* XXX hack */
}
return (error);
}
SYSCTL_PROC(_kern, OID_AUTO, consmute, CTLTYPE_INT|CTLFLAG_RW,
0, sizeof(cn_mute), sysctl_kern_consmute, "I", "");
static int
cn_devopen(struct cn_device *cnd, struct thread *td, int forceopen)
{
char path[CNDEVPATHMAX];
struct nameidata nd;
struct vnode *vp;
struct cdev *dev;
struct cdevsw *csw;
int error;
if ((vp = cnd->cnd_vp) != NULL) {
if (!forceopen && vp->v_type != VBAD) {
dev = vp->v_rdev;
csw = dev_refthread(dev);
if (csw == NULL)
return (ENXIO);
error = (*csw->d_open)(dev, openflag, 0, td);
dev_relthread(dev);
return (error);
}
cnd->cnd_vp = NULL;
vn_close(vp, openflag, td->td_ucred, td);
}
snprintf(path, sizeof(path), "/dev/%s", cnd->cnd_cn->cn_name);
NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, path, td);
error = vn_open(&nd, &openflag, 0, NULL);
if (error == 0) {
NDFREE(&nd, NDF_ONLY_PNBUF);
VOP_UNLOCK(nd.ni_vp, 0);
if (nd.ni_vp->v_type == VCHR)
cnd->cnd_vp = nd.ni_vp;
else
vn_close(nd.ni_vp, openflag, td->td_ucred, td);
}
return (cnd->cnd_vp != NULL);
}
static int
cnopen(struct cdev *dev, int flag, int mode, struct thread *td)
{
struct cn_device *cnd;
openflag = flag | FWRITE; /* XXX */
cn_is_open = 1; /* console is logically open */
if (cn_mute)
return (0);
STAILQ_FOREACH(cnd, &cn_devlist, cnd_next)
cn_devopen(cnd, td, 0);
return (0);
}
static int
cnclose(struct cdev *dev, int flag, int mode, struct thread *td)
{
struct cn_device *cnd;
struct vnode *vp;
STAILQ_FOREACH(cnd, &cn_devlist, cnd_next) {
if ((vp = cnd->cnd_vp) == NULL)
continue;
cnd->cnd_vp = NULL;
vn_close(vp, openflag, td->td_ucred, td);
}
cn_is_open = 0;
return (0);
}
static int
cnread(struct cdev *dev, struct uio *uio, int flag)
{
struct cn_device *cnd;
struct cdevsw *csw;
int error;
cnd = STAILQ_FIRST(&cn_devlist);
if (cn_mute || CND_INVALID(cnd, curthread))
return (0);
dev = cnd->cnd_vp->v_rdev;
csw = dev_refthread(dev);
if (csw == NULL)
return (ENXIO);
error = (csw->d_read)(dev, uio, flag);
dev_relthread(dev);
return (error);
}
static int
cnwrite(struct cdev *dev, struct uio *uio, int flag)
{
struct cn_device *cnd;
struct cdevsw *csw;
int error;
cnd = STAILQ_FIRST(&cn_devlist);
if (cn_mute || CND_INVALID(cnd, curthread))
goto done;
if (constty)
dev = constty->t_dev;
else
dev = cnd->cnd_vp->v_rdev;
if (dev != NULL) {
log_console(uio);
csw = dev_refthread(dev);
if (csw == NULL)
return (ENXIO);
error = (csw->d_write)(dev, uio, flag);
dev_relthread(dev);
return (error);
}
done:
uio->uio_resid = 0; /* dump the data */
return (0);
}
static int
cnioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *td)
{
struct cn_device *cnd;
struct cdevsw *csw;
int error;
cnd = STAILQ_FIRST(&cn_devlist);
if (cn_mute || CND_INVALID(cnd, td))
return (0);
/*
* Superuser can always use this to wrest control of console
* output from the "virtual" console.
*/
if (cmd == TIOCCONS && constty) {
error = priv_check(td, PRIV_TTY_CONSOLE);
if (error)
return (error);
constty = NULL;
return (0);
}
dev = cnd->cnd_vp->v_rdev;
if (dev == NULL)
return (0); /* XXX : ENOTTY ? */
csw = dev_refthread(dev);
if (csw == NULL)
return (ENXIO);
error = (csw->d_ioctl)(dev, cmd, data, flag, td);
dev_relthread(dev);
return (error);
}
/*
* XXX
* poll/kqfilter do not appear to be correct
*/
static int
cnpoll(struct cdev *dev, int events, struct thread *td)
{
struct cn_device *cnd;
struct cdevsw *csw;
int error;
cnd = STAILQ_FIRST(&cn_devlist);
if (cn_mute || CND_INVALID(cnd, td))
return (0);
dev = cnd->cnd_vp->v_rdev;
if (dev == NULL)
return (0);
csw = dev_refthread(dev);
if (csw == NULL)
return (ENXIO);
error = (csw->d_poll)(dev, events, td);
dev_relthread(dev);
return (error);
}
static int
cnkqfilter(struct cdev *dev, struct knote *kn)
{
struct cn_device *cnd;
struct cdevsw *csw;
int error;
cnd = STAILQ_FIRST(&cn_devlist);
if (cn_mute || CND_INVALID(cnd, curthread))
return (EINVAL);
dev = cnd->cnd_vp->v_rdev;
if (dev == NULL)
return (ENXIO);
csw = dev_refthread(dev);
if (csw == NULL)
return (ENXIO);
error = (csw->d_kqfilter)(dev, kn);
dev_relthread(dev);
return (error);
}
/*
* Low level console routines.
*/
int
cngetc(void)
{
int c;
if (cn_mute)
return (-1);
while ((c = cncheckc()) == -1)
;
if (c == '\r')
c = '\n'; /* console input is always ICRNL */
return (c);
}
int
cncheckc(void)
{
struct cn_device *cnd;
struct consdev *cn;
int c;
if (cn_mute)
return (-1);
STAILQ_FOREACH(cnd, &cn_devlist, cnd_next) {
cn = cnd->cnd_cn;
if (!kdb_active || !(cn->cn_flags & CN_FLAG_NODEBUG)) {
if (cn->cn_checkc != NULL)
c = cn->cn_checkc(cn);
else
c = cn->cn_getc(cn);
if (c != -1) {
return (c);
}
}
}
return (-1);
}
void
cnputc(int c)
{
struct cn_device *cnd;
struct consdev *cn;
char *cp;
if (cn_mute || c == '\0')
return;
STAILQ_FOREACH(cnd, &cn_devlist, cnd_next) {
cn = cnd->cnd_cn;
if (!kdb_active || !(cn->cn_flags & CN_FLAG_NODEBUG)) {
if (c == '\n')
cn->cn_putc(cn, '\r');
cn->cn_putc(cn, c);
}
}
if (console_pausing && c == '\n' && !kdb_active) {
for (cp = console_pausestr; *cp != '\0'; cp++)
cnputc(*cp);
if (cngetc() == '.')
console_pausing = 0;
cnputc('\r');
for (cp = console_pausestr; *cp != '\0'; cp++)
cnputc(' ');
cnputc('\r');
}
}
void
cnputs(char *p)
{
int c;
int unlock_reqd = 0;
if (use_cnputs_mtx) {
mtx_lock_spin(&cnputs_mtx);
unlock_reqd = 1;
}
while ((c = *p++) != '\0')
cnputc(c);
if (unlock_reqd)
mtx_unlock_spin(&cnputs_mtx);
}
static int consmsgbuf_size = 8192;
SYSCTL_INT(_kern, OID_AUTO, consmsgbuf_size, CTLFLAG_RW, &consmsgbuf_size, 0,
"");
/*
* Redirect console output to a tty.
*/
void
constty_set(struct tty *tp)
{
int size;
KASSERT(tp != NULL, ("constty_set: NULL tp"));
if (consbuf == NULL) {
size = consmsgbuf_size;
consbuf = malloc(size, M_TTYS, M_WAITOK);
msgbuf_init(&consmsgbuf, consbuf, size);
callout_init(&conscallout, 0);
}
constty = tp;
constty_timeout(NULL);
}
/*
* Disable console redirection to a tty.
*/
void
constty_clear(void)
{
int c;
constty = NULL;
if (consbuf == NULL)
return;
callout_stop(&conscallout);
while ((c = msgbuf_getchar(&consmsgbuf)) != -1)
cnputc(c);
free(consbuf, M_TTYS);
consbuf = NULL;
}
/* Times per second to check for pending console tty messages. */
static int constty_wakeups_per_second = 5;
SYSCTL_INT(_kern, OID_AUTO, constty_wakeups_per_second, CTLFLAG_RW,
&constty_wakeups_per_second, 0, "");
static void
constty_timeout(void *arg)
{
int c;
while (constty != NULL && (c = msgbuf_getchar(&consmsgbuf)) != -1) {
if (tputchar(c, constty) < 0)
constty = NULL;
}
if (constty != NULL) {
callout_reset(&conscallout, hz / constty_wakeups_per_second,
constty_timeout, NULL);
} else {
/* Deallocate the constty buffer memory. */
constty_clear();
}
}
static void
cn_drvinit(void *unused)
{
make_dev(&cn_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "console");
mtx_init(&cnputs_mtx, "cnputs_mtx", NULL, MTX_SPIN | MTX_NOWITNESS);
use_cnputs_mtx = 1;
}
SYSINIT(cndev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, cn_drvinit, NULL)