freebsd-dev/sys/kern/tty_cons.c
David Greenman e4794aea16 Brute-force fix for the "hanging console" problem. Simply _don't_ call
the device close routine. This works because the device close calls
the line discipline close (which only flushes the output buffers) and
the ttyclose() routine, which does little of nothing except screw with
the session and process group fields (which is what was causing all
the problems).
1994-01-22 22:48:21 +00:00

235 lines
5.4 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 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
* $Id: cons.c,v 1.7 1993/12/12 12:22:55 davidg Exp $
*/
#include "sys/param.h"
#include "sys/proc.h"
#include "sys/user.h"
#include "sys/systm.h"
#include "sys/buf.h"
#include "sys/ioctl.h"
#include "sys/tty.h"
#include "sys/file.h"
#include "sys/conf.h"
#include "machine/stdarg.h"
#include "machine/cons.h"
/* XXX - all this could be autoconfig()ed */
int pccnprobe(), pccninit(), pccngetc(), pccnputc();
#include "sio.h"
#if NSIO > 0
int siocnprobe(), siocninit(), siocngetc(), siocnputc();
#endif
#include "com.h"
#if NCOM > 0
int comcnprobe(), comcninit(), comcngetc(), comcnputc();
#endif
struct consdev constab[] = {
{ pccnprobe, pccninit, pccngetc, pccnputc },
#if NSIO > 0
{ siocnprobe, siocninit, siocngetc, siocnputc },
#endif
#if NCOM > 0
{ comcnprobe, comcninit, comcngetc, comcnputc },
#endif
{ 0 },
};
/* end XXX */
struct tty *constty = 0; /* virtual console output device */
struct consdev *cn_tab; /* physical console device info */
struct tty *cn_tty; /* XXX: console tty struct for tprintf */
void
cninit()
{
register struct consdev *cp;
/*
* Collect information about all possible consoles
* and find the one with highest priority
*/
for (cp = constab; cp->cn_probe; cp++) {
(*cp->cn_probe)(cp);
if (cp->cn_pri > CN_DEAD &&
(cn_tab == NULL || cp->cn_pri > cn_tab->cn_pri))
cn_tab = cp;
}
/*
* No console, we can handle it
*/
if ((cp = cn_tab) == NULL)
return;
/*
* Turn on console
*/
cn_tty = cp->cn_tp;
(*cp->cn_init)(cp);
}
int
cnopen(dev, flag, mode, p)
dev_t dev;
int flag, mode;
struct proc *p;
{
if (cn_tab == NULL)
return (0);
dev = cn_tab->cn_dev;
return ((*cdevsw[major(dev)].d_open)(dev, flag, mode, p));
}
int
cnclose(dev, flag, mode, p)
dev_t dev;
int flag, mode;
struct proc *p;
{
return(0);
#if 0
if (cn_tab == NULL)
return (0);
dev = cn_tab->cn_dev;
return ((*cdevsw[major(dev)].d_close)(dev, flag, mode, p));
#endif
}
int
cnread(dev, uio, flag)
dev_t dev;
struct uio *uio;
int flag;
{
if (cn_tab == NULL)
return (0);
dev = cn_tab->cn_dev;
return ((*cdevsw[major(dev)].d_read)(dev, uio, flag));
}
int
cnwrite(dev, uio, flag)
dev_t dev;
struct uio *uio;
int flag;
{
if (cn_tab == NULL)
return (0);
if (constty) /* 16 Aug 92*/
dev = constty->t_dev;
else
dev = cn_tab->cn_dev;
return ((*cdevsw[major(dev)].d_write)(dev, uio, flag));
}
int
cnioctl(dev, cmd, data, flag, p)
dev_t dev;
int cmd;
caddr_t data;
int flag;
struct proc *p;
{
int error;
if (cn_tab == NULL)
return (0);
/*
* Superuser can always use this to wrest control of console
* output from the "virtual" console.
*/
if (cmd == TIOCCONS && constty) {
error = suser(p->p_ucred, (u_short *) NULL);
if (error)
return (error);
constty = NULL;
return (0);
}
dev = cn_tab->cn_dev;
return ((*cdevsw[major(dev)].d_ioctl)(dev, cmd, data, flag, p));
}
/*ARGSUSED*/
int
cnselect(dev, rw, p)
dev_t dev;
int rw;
struct proc *p;
{
if (cn_tab == NULL)
return (1);
return (ttselect(cn_tab->cn_dev, rw, p));
}
int
cngetc()
{
if (cn_tab == NULL)
return (0);
return ((*cn_tab->cn_getc)(cn_tab->cn_dev));
}
void
cnputc(c)
register int c;
{
if (cn_tab == NULL)
return;
if (c) {
(*cn_tab->cn_putc)(cn_tab->cn_dev, c);
if (c == '\n')
(*cn_tab->cn_putc)(cn_tab->cn_dev, '\r');
}
}
int
pg(const char *p, ...) {
va_list args;
va_start(args, p);
printf("%r\n>", p, args);
return(cngetc());
}