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mirror of https://git.FreeBSD.org/src.git synced 2024-12-23 11:18:54 +00:00
freebsd/sys/kern/subr_prf.c
Joerg Wunsch 4fb0b0de3e Implement a simple hook (or hack?) to allow graphics device console
drivers to protect DDB from being invoked while the console is in
process-controlled (i.e., graphics) mode.

Implement the logic to use this hook from within pcvt.  (I'm sure
Søren will do the syscons part RSN).

I've still got one occasion where the system stalled, but my attempts
to trigger the situation artificially resulted int the expected
behaviour.  It's hard to track bugs without the console and DDB
available. :-/
1995-04-08 21:32:11 +00:00

621 lines
13 KiB
C

/*-
* Copyright (c) 1986, 1988, 1991, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* 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.
*
* @(#)subr_prf.c 8.3 (Berkeley) 1/21/94
* $Id: subr_prf.c,v 1.12 1995/04/01 20:18:43 joerg Exp $
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/buf.h>
#include <sys/conf.h>
#include <sys/reboot.h>
#include <sys/msgbuf.h>
#include <sys/proc.h>
#include <sys/ioctl.h>
#include <sys/vnode.h>
#include <sys/file.h>
#include <sys/tty.h>
#include <sys/tprintf.h>
#include <sys/syslog.h>
#include <sys/malloc.h>
#include <machine/cons.h>
/*
* Note that stdarg.h and the ANSI style va_start macro is used for both
* ANSI and traditional C compilers.
*/
#include <machine/stdarg.h>
#ifdef KADB
#include <machine/kdbparam.h>
#endif
#define TOCONS 0x01
#define TOTTY 0x02
#define TOLOG 0x04
struct tty *constty; /* pointer to console "window" tty */
void (*v_putc)(int) = cnputc; /* routine to putc on virtual console */
void logpri __P((int level));
static void putchar __P((int ch, int flags, struct tty *tp));
static char *ksprintn __P((u_long num, int base, int *len));
int consintr = 1; /* Ok to handle console interrupts? */
/*
* Variable panicstr contains argument to first call to panic; used as flag
* to indicate that the kernel has already called panic.
*/
const char *panicstr;
/*
* Panic is called on unresolvable fatal errors. It prints "panic: mesg",
* and then reboots. If we are called twice, then we avoid trying to sync
* the disks as this often leads to recursive panics.
*/
#ifdef __GNUC__
__dead /* panic() does not return */
#endif
void
#ifdef __STDC__
panic(const char *fmt, ...)
#else
panic(fmt, va_alist)
char *fmt;
#endif
{
int bootopt;
va_list ap;
bootopt = RB_AUTOBOOT | RB_DUMP;
if (panicstr)
bootopt |= RB_NOSYNC;
else
panicstr = fmt;
va_start(ap, fmt);
printf("panic: %r\n", fmt, ap);
va_end(ap);
#ifdef KGDB
kgdb_panic();
#endif
#ifdef KADB
if (boothowto & RB_KDB)
kdbpanic();
#endif
#ifdef DDB
Debugger ("panic");
#endif
boot(bootopt);
}
/*
* Warn that a system table is full.
*/
void
tablefull(tab)
const char *tab;
{
log(LOG_ERR, "%s: table is full\n", tab);
}
/*
* Uprintf prints to the controlling terminal for the current process.
* It may block if the tty queue is overfull. No message is printed if
* the queue does not clear in a reasonable time.
*/
void
#ifdef __STDC__
uprintf(const char *fmt, ...)
#else
uprintf(fmt, va_alist)
char *fmt;
#endif
{
register struct proc *p = curproc;
va_list ap;
if (p->p_flag & P_CONTROLT && p->p_session->s_ttyvp) {
va_start(ap, fmt);
kprintf(fmt, TOTTY, p->p_session->s_ttyp, ap);
va_end(ap);
}
}
tpr_t
tprintf_open(p)
register struct proc *p;
{
if (p->p_flag & P_CONTROLT && p->p_session->s_ttyvp) {
SESSHOLD(p->p_session);
return ((tpr_t) p->p_session);
}
return ((tpr_t) NULL);
}
void
tprintf_close(sess)
tpr_t sess;
{
if (sess)
SESSRELE((struct session *) sess);
}
/*
* tprintf prints on the controlling terminal associated
* with the given session.
*/
void
#ifdef __STDC__
tprintf(tpr_t tpr, const char *fmt, ...)
#else
tprintf(tpr, fmt, va_alist)
tpr_t tpr;
char *fmt;
#endif
{
register struct session *sess = (struct session *)tpr;
struct tty *tp = NULL;
int flags = TOLOG;
va_list ap;
logpri(LOG_INFO);
if (sess && sess->s_ttyvp && ttycheckoutq(sess->s_ttyp, 0)) {
flags |= TOTTY;
tp = sess->s_ttyp;
}
va_start(ap, fmt);
kprintf(fmt, flags, tp, ap);
va_end(ap);
logwakeup();
}
/*
* Ttyprintf displays a message on a tty; it should be used only by
* the tty driver, or anything that knows the underlying tty will not
* be revoke(2)'d away. Other callers should use tprintf.
*/
void
#ifdef __STDC__
ttyprintf(struct tty *tp, const char *fmt, ...)
#else
ttyprintf(tp, fmt, va_alist)
struct tty *tp;
char *fmt;
#endif
{
va_list ap;
va_start(ap, fmt);
kprintf(fmt, TOTTY, tp, ap);
va_end(ap);
}
extern int log_open;
/*
* Log writes to the log buffer, and guarantees not to sleep (so can be
* called by interrupt routines). If there is no process reading the
* log yet, it writes to the console also.
*/
void
#ifdef __STDC__
log(int level, const char *fmt, ...)
#else
log(level, fmt, va_alist)
int level;
char *fmt;
#endif
{
register int s;
va_list ap;
s = splhigh();
logpri(level);
va_start(ap, fmt);
kprintf(fmt, TOLOG, NULL, ap);
splx(s);
va_end(ap);
if (!log_open) {
va_start(ap, fmt);
kprintf(fmt, TOCONS, NULL, ap);
va_end(ap);
}
logwakeup();
}
void
logpri(level)
int level;
{
register char *p;
putchar('<', TOLOG, NULL);
for (p = ksprintn((u_long)level, 10, NULL); *p;)
putchar(*p--, TOLOG, NULL);
putchar('>', TOLOG, NULL);
}
void
#ifdef __STDC__
addlog(const char *fmt, ...)
#else
addlog(fmt, va_alist)
char *fmt;
#endif
{
register int s;
va_list ap;
s = splhigh();
va_start(ap, fmt);
kprintf(fmt, TOLOG, NULL, ap);
splx(s);
va_end(ap);
if (!log_open) {
va_start(ap, fmt);
kprintf(fmt, TOCONS, NULL, ap);
va_end(ap);
}
logwakeup();
}
void
#ifdef __STDC__
printf(const char *fmt, ...)
#else
printf(fmt, va_alist)
char *fmt;
#endif
{
va_list ap;
register int savintr;
savintr = consintr; /* disable interrupts */
consintr = 0;
va_start(ap, fmt);
kprintf(fmt, TOCONS | TOLOG, NULL, ap);
va_end(ap);
if (!panicstr)
logwakeup();
consintr = savintr; /* reenable interrupts */
}
/*
* Scaled down version of printf(3).
*
* Two additional formats:
*
* The format %b is supported to decode error registers.
* Its usage is:
*
* printf("reg=%b\n", regval, "<base><arg>*");
*
* where <base> is the output base expressed as a control character, e.g.
* \10 gives octal; \20 gives hex. Each arg is a sequence of characters,
* the first of which gives the bit number to be inspected (origin 1), and
* the next characters (up to a control character, i.e. a character <= 32),
* give the name of the register. Thus:
*
* kprintf("reg=%b\n", 3, "\10\2BITTWO\1BITONE\n");
*
* would produce output:
*
* reg=3<BITTWO,BITONE>
*
* The format %r passes an additional format string and argument list
* recursively. Its usage is:
*
* fn(char *fmt, ...)
* {
* va_list ap;
* va_start(ap, fmt);
* printf("prefix: %r: suffix\n", fmt, ap);
* va_end(ap);
* }
*
* Space or zero padding and a field width are supported for the numeric
* formats only.
*/
void
kprintf(fmt, flags, tp, ap)
register const char *fmt;
int flags;
struct tty *tp;
va_list ap;
{
register char *p, *q;
register int ch, n;
u_long ul;
int base, lflag, tmp, width;
char padc;
if (fmt == NULL)
fmt = "(fmt null)\n";
for (;;) {
padc = ' ';
width = 0;
while ((ch = *(u_char *)fmt++) != '%') {
if (ch == '\0')
return;
putchar(ch, flags, tp);
}
lflag = 0;
reswitch: switch (ch = *(u_char *)fmt++) {
case '0':
padc = '0';
goto reswitch;
case '1': case '2': case '3': case '4':
case '5': case '6': case '7': case '8': case '9':
for (width = 0;; ++fmt) {
width = width * 10 + ch - '0';
ch = *fmt;
if (ch < '0' || ch > '9')
break;
}
goto reswitch;
case 'l':
lflag = 1;
goto reswitch;
case 'b':
ul = va_arg(ap, int);
p = va_arg(ap, char *);
for (q = ksprintn(ul, *p++, NULL); *q;)
putchar(*q--, flags, tp);
if (!ul)
break;
for (tmp = 0; *p;) {
n = *p++;
if (ul & (1 << (n - 1))) {
putchar(tmp ? ',' : '<', flags, tp);
for (; (n = *p) > ' '; ++p)
putchar(n, flags, tp);
tmp = 1;
} else
for (; *p > ' '; ++p)
continue;
}
if (tmp)
putchar('>', flags, tp);
break;
case 'c':
putchar(va_arg(ap, int), flags, tp);
break;
case 'r':
p = va_arg(ap, char *);
kprintf(p, flags, tp, va_arg(ap, va_list));
break;
case 's':
p = va_arg(ap, char *);
if (p == NULL)
p = "(null)";
while (*p)
putchar(*p++, flags, tp);
break;
case 'd':
ul = lflag ? va_arg(ap, long) : va_arg(ap, int);
if ((long)ul < 0) {
putchar('-', flags, tp);
ul = -(long)ul;
}
base = 10;
goto number;
case 'o':
ul = lflag ? va_arg(ap, u_long) : va_arg(ap, u_int);
base = 8;
goto number;
case 'u':
ul = lflag ? va_arg(ap, u_long) : va_arg(ap, u_int);
base = 10;
goto number;
case 'p':
ul = (u_long) va_arg(ap, void *);
width=8;
base=16;
putchar('0',flags,tp);
putchar('x',flags,tp);
goto number;
case 'x':
ul = lflag ? va_arg(ap, u_long) : va_arg(ap, u_int);
base = 16;
number: p = ksprintn(ul, base, &tmp);
if (width && (width -= tmp) > 0)
while (width--)
putchar(padc, flags, tp);
while (*p)
putchar(*p--, flags, tp);
break;
default:
putchar('%', flags, tp);
if (lflag)
putchar('l', flags, tp);
/* FALLTHROUGH */
case '%':
putchar(ch, flags, tp);
}
}
}
/*
* Print a character on console or users terminal. If destination is
* the console then the last MSGBUFS characters are saved in msgbuf for
* inspection later.
*/
static void
putchar(c, flags, tp)
register int c;
int flags;
struct tty *tp;
{
register struct msgbuf *mbp;
if (panicstr)
constty = NULL;
if ((flags & TOCONS) && tp == NULL && constty) {
tp = constty;
flags |= TOTTY;
}
if ((flags & TOTTY) && tp && tputchar(c, tp) < 0 &&
(flags & TOCONS) && tp == constty)
constty = NULL;
if ((flags & TOLOG) &&
c != '\0' && c != '\r' && c != 0177 && msgbufmapped) {
mbp = msgbufp;
if (mbp->msg_magic != MSG_MAGIC) {
bzero((caddr_t)mbp, sizeof(*mbp));
mbp->msg_magic = MSG_MAGIC;
}
mbp->msg_bufc[mbp->msg_bufx++] = c;
if (mbp->msg_bufx >= MSG_BSIZE)
mbp->msg_bufx = 0;
if (mbp->msg_bufr == mbp->msg_bufx) {
mbp->msg_bufr++;
if (mbp->msg_bufr >= MSG_BSIZE)
mbp->msg_bufr = 0;
}
}
if ((flags & TOCONS) && constty == NULL && c != '\0')
(*v_putc)(c);
}
/*
* Scaled down version of sprintf(3).
*/
#ifdef __STDC__
int
sprintf(char *buf, const char *cfmt, ...)
#else
int
sprintf(buf, cfmt, va_alist)
char *buf, *cfmt;
#endif
{
register const char *fmt = cfmt;
register char *p, *bp;
register int ch, base;
u_long ul;
int lflag;
va_list ap;
va_start(ap, cfmt);
for (bp = buf; ; ) {
while ((ch = *(u_char *)fmt++) != '%')
if ((*bp++ = ch) == '\0')
return ((bp - buf) - 1);
lflag = 0;
reswitch: switch (ch = *(u_char *)fmt++) {
case 'l':
lflag = 1;
goto reswitch;
case 'c':
*bp++ = va_arg(ap, int);
break;
case 's':
p = va_arg(ap, char *);
while (*p)
*bp++ = *p++;
break;
case 'd':
ul = lflag ? va_arg(ap, long) : va_arg(ap, int);
if ((long)ul < 0) {
*bp++ = '-';
ul = -(long)ul;
}
base = 10;
goto number;
break;
case 'o':
ul = lflag ? va_arg(ap, u_long) : va_arg(ap, u_int);
base = 8;
goto number;
break;
case 'u':
ul = lflag ? va_arg(ap, u_long) : va_arg(ap, u_int);
base = 10;
goto number;
break;
case 'x':
ul = lflag ? va_arg(ap, u_long) : va_arg(ap, u_int);
base = 16;
number: for (p = ksprintn(ul, base, NULL); *p;)
*bp++ = *p--;
break;
default:
*bp++ = '%';
if (lflag)
*bp++ = 'l';
/* FALLTHROUGH */
case '%':
*bp++ = ch;
}
}
va_end(ap);
}
/*
* Put a number (base <= 16) in a buffer in reverse order; return an
* optional length and a pointer to the NULL terminated (preceded?)
* buffer.
*/
static char *
ksprintn(ul, base, lenp)
register u_long ul;
register int base, *lenp;
{ /* A long in base 8, plus NULL. */
static char buf[sizeof(long) * NBBY / 3 + 2];
register char *p;
p = buf;
do {
*++p = "0123456789abcdef"[ul % base];
} while (ul /= base);
if (lenp)
*lenp = p - buf;
return (p);
}