subr_prf.c

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/*	$NetBSD: subr_prf.c,v 1.76 2000/08/09 10:22:31 tv Exp $	*/

/*-
 * 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	8.4 (Berkeley) 5/4/95
 */

#include "opt_ddb.h"
#include "opt_ipkdb.h"
#include "opt_multiprocessor.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/buf.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 <sys/lock.h>

#ifndef OSKIT
#include <dev/cons.h>
#endif

#ifdef DDB
#include <ddb/ddbvar.h>
#include <machine/db_machdep.h>
#include <ddb/db_command.h>
#include <ddb/db_interface.h>
#endif

#ifdef IPKDB
#include <ipkdb/ipkdb.h>
#endif

#if defined(MULTIPROCESSOR)
struct simplelock kprintf_slock = SIMPLELOCK_INITIALIZER;

/*
 * Use cpu_simple_lock() and cpu_simple_unlock().  These are the actual
 * atomic locking operations, and never attempt to print debugging
 * information.
 */
#define	KPRINTF_MUTEX_ENTER(s)						\
do {									\
	(s) = splhigh();						\
	__cpu_simple_lock(&kprintf_slock.lock_data);			\
} while (0)

#define	KPRINTF_MUTEX_EXIT(s)						\
do {									\
	__cpu_simple_unlock(&kprintf_slock.lock_data);			\
	splx((s));							\
} while (0)
#else /* ! MULTIPROCESSOR */
#define	KPRINTF_MUTEX_ENTER(s)	(s) = splhigh()
#define	KPRINTF_MUTEX_EXIT(s)	splx((s))
#endif /* MULTIPROCESSOR */

/*
 * note that stdarg.h and the ansi style va_start macro is used for both
 * ansi and traditional c complers.
 * XXX: this requires that stdarg.h define: va_alist and va_dcl
 */
#include <machine/stdarg.h>


#ifdef KGDB
#include <sys/kgdb.h>
#include <machine/cpu.h>
#endif
#ifdef DDB
#include <ddb/db_output.h>	/* db_printf, db_putchar prototypes */
#endif


/*
 * defines
 */

/* flags for kprintf */
#define TOCONS		0x01	/* to the console */
#define TOTTY		0x02	/* to the process' tty */
#define TOLOG		0x04	/* to the kernel message buffer */
#define TOBUFONLY	0x08	/* to the buffer (only) [for snprintf] */
#define TODDB		0x10	/* to ddb console */

/* max size buffer kprintf needs to print quad_t [size in base 8 + \0] */
#define KPRINTF_BUFSIZE		(sizeof(quad_t) * NBBY / 3 + 2)

#ifndef OSKIT

/*
 * local prototypes
 */

static int	 kprintf __P((const char *, int, void *, 
				char *, va_list));
static void	 putchar __P((int, int, struct tty *));
static void	 klogpri __P((int));

/*
 * globals
 */

struct	tty *constty;	/* pointer to console "window" tty */
extern	int log_open;	/* subr_log: is /dev/klog open? */
#endif /*OSKIT*/

const	char *panicstr; /* arg to first call to panic (used as a flag
			   to indicate that panic has already been called). */
int	doing_shutdown;	/* set to indicate shutdown in progress */

#ifndef OSKIT
/*
 * v_putc: routine to putc on virtual console
 *
 * the v_putc pointer can be used to redirect the console cnputc elsewhere
 * [e.g. to a "virtual console"].
 */

void (*v_putc) __P((int)) = cnputc;	/* start with cnputc (normal cons) */


/*
 * functions
 */

/*
 * tablefull: warn that a system table is full
 */

void
tablefull(tab, hint)
	const char *tab, *hint;
{
	if (hint)
		log(LOG_ERR, "%s: table is full - %s\n", tab, hint);
	else
		log(LOG_ERR, "%s: table is full\n", tab);
}

/*
 * panic: handle an unresolvable fatal error
 *
 * prints "panic: <message>" and reboots.   if called twice (i.e. recursive
 * call) we avoid trying to sync the disk and just reboot (to avoid 
 * recursive panics).
 */

void
#ifdef __STDC__
panic(const char *fmt, ...)
#else
panic(fmt, va_alist)
	char *fmt;
	va_dcl
#endif
{
	int bootopt;
	va_list ap;

	bootopt = RB_AUTOBOOT | RB_DUMP;
	if (doing_shutdown)
		bootopt |= RB_NOSYNC;
	if (!panicstr)
		panicstr = fmt;
	doing_shutdown = 1;
	
	va_start(ap, fmt);
	printf("panic: ");
	vprintf(fmt, ap);
	printf("\n");
	va_end(ap);

#ifdef IPKDB
	ipkdb_panic();
#endif
#ifdef KGDB
	kgdb_panic();
#endif
#ifdef KADB
	if (boothowto & RB_KDB)
		kdbpanic();
#endif
#ifdef DDB
	if (db_onpanic)
		Debugger();
	else {
		static int intrace = 0;

		if (intrace==0) {
			intrace=1;
			printf("Begin traceback...\n");
			db_stack_trace_print(
			    (db_expr_t)__builtin_frame_address(0),
			    TRUE, 65535, "", printf);
			printf("End traceback...\n");
			intrace=0;
		} else
			printf("Faulted in mid-traceback; aborting...");
	}
#endif
	cpu_reboot(bootopt, NULL);
}

/*
 * kernel logging functions: log, logpri, addlog
 */

/*
 * log: write to the log buffer
 *
 * => will not sleep [so safe to call from interrupt]
 * => will log to console if /dev/klog isn't open
 */

void
#ifdef __STDC__
log(int level, const char *fmt, ...)
#else
log(level, fmt, va_alist)
	int level;
	char *fmt;
	va_dcl
#endif
{
	int s;
	va_list ap;

	KPRINTF_MUTEX_ENTER(s);

	klogpri(level);		/* log the level first */
	va_start(ap, fmt);
	kprintf(fmt, TOLOG, NULL, NULL, ap);
	va_end(ap);
	if (!log_open) {
		va_start(ap, fmt);
		kprintf(fmt, TOCONS, NULL, NULL, ap);
		va_end(ap);
	}

	KPRINTF_MUTEX_EXIT(s);

	logwakeup();		/* wake up anyone waiting for log msgs */
}

/*
 * vlog: write to the log buffer [already have va_alist]
 */

void
vlog(level, fmt, ap)
	int level;
	const char *fmt;
	va_list ap;
{
	int s;

	KPRINTF_MUTEX_ENTER(s);

	klogpri(level);		/* log the level first */
	kprintf(fmt, TOLOG, NULL, NULL, ap);
	if (!log_open)
		kprintf(fmt, TOCONS, NULL, NULL, ap);

	KPRINTF_MUTEX_EXIT(s);

	logwakeup();		/* wake up anyone waiting for log msgs */
}

/*
 * logpri: log the priority level to the klog
 */

void
logpri(level)
	int level;
{
	int s;

	KPRINTF_MUTEX_ENTER(s);
	klogpri(level);
	KPRINTF_MUTEX_EXIT(s);
}

/*
 * Note: we must be in the mutex here!
 */
static void
klogpri(level)
	int level;
{
	char *p;
	char snbuf[KPRINTF_BUFSIZE];

	putchar('<', TOLOG, NULL);
	snprintf(snbuf, sizeof(snbuf), "%d", level);
	for (p = snbuf ; *p ; p++)
		putchar(*p, TOLOG, NULL);
	putchar('>', TOLOG, NULL);
}

/*
 * addlog: add info to previous log message
 */

void
#ifdef __STDC__
addlog(const char *fmt, ...)
#else
addlog(fmt, va_alist)
	char *fmt;
	va_dcl
#endif
{
	int s;
	va_list ap;

	KPRINTF_MUTEX_ENTER(s);

	va_start(ap, fmt);
	kprintf(fmt, TOLOG, NULL, NULL, ap);
	va_end(ap);
	if (!log_open) {
		va_start(ap, fmt);
		kprintf(fmt, TOCONS, NULL, NULL, ap);
		va_end(ap);
	}

	KPRINTF_MUTEX_EXIT(s);

	logwakeup();
}


/*
 * putchar: print a single character on console or user terminal.
 *
 * => if console, then the last MSGBUFS chars are saved in msgbuf
 *	for inspection later (e.g. dmesg/syslog)
 * => we must already be in the mutex!
 */
static void
putchar(c, flags, tp)
	int c;
	int flags;
	struct tty *tp;
{
	struct kern_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 && msgbufenabled) {
		mbp = msgbufp;
		if (mbp->msg_magic != MSG_MAGIC) {
			/*
			 * Arguably should panic or somehow notify the
			 * user...  but how?  Panic may be too drastic,
			 * and would obliterate the message being kicked
			 * out (maybe a panic itself), and printf
			 * would invoke us recursively.  Silently punt
			 * for now.  If syslog is running, it should
			 * notice.
			 */
			msgbufenabled = 0;
		} else {
			mbp->msg_bufc[mbp->msg_bufx++] = c;
			if (mbp->msg_bufx < 0 || mbp->msg_bufx >= mbp->msg_bufs)
				mbp->msg_bufx = 0;
			/* If the buffer is full, keep the most recent data. */
			if (mbp->msg_bufr == mbp->msg_bufx) {
				 if (++mbp->msg_bufr >= mbp->msg_bufs)
					mbp->msg_bufr = 0;
			}
		}
	}
	if ((flags & TOCONS) && constty == NULL && c != '\0')
		(*v_putc)(c);
#ifdef DDB
	if (flags & TODDB)
		db_putchar(c);
#endif
}


/*
 * uprintf: print to the controlling tty of the current process
 *
 * => we may block if the tty queue is full
 * => no message is printed if the queue doesn't clear in a reasonable
 *	time
 */

void
#ifdef __STDC__
uprintf(const char *fmt, ...)
#else
uprintf(fmt, va_alist)
	char *fmt;
	va_dcl
#endif
{
	struct proc *p = curproc;
	va_list ap;

	if (p->p_flag & P_CONTROLT && p->p_session->s_ttyvp) {
		/* No mutex needed; going to process TTY. */
		va_start(ap, fmt);
		kprintf(fmt, TOTTY, p->p_session->s_ttyp, NULL, ap);
		va_end(ap);
	}
}

/*
 * tprintf functions: used to send messages to a specific process
 *
 * usage:
 *   get a tpr_t handle on a process "p" by using "tprintf_open(p)"
 *   use the handle when calling "tprintf"
 *   when done, do a "tprintf_close" to drop the handle
 */

/*
 * tprintf_open: get a tprintf handle on a process "p"
 *
 * => returns NULL if process can't be printed to
 */

tpr_t
tprintf_open(p)
	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);
}

/*
 * tprintf_close: dispose of a tprintf handle obtained with tprintf_open
 */

void
tprintf_close(sess)
	tpr_t sess;
{

	if (sess)
		SESSRELE((struct session *) sess);
}

/*
 * tprintf: given tprintf handle to a process [obtained with tprintf_open], 
 * send a message to the controlling tty for that process.
 *
 * => also sends message to /dev/klog
 */
void
#ifdef __STDC__
tprintf(tpr_t tpr, const char *fmt, ...)
#else
tprintf(tpr, fmt, va_alist)
	tpr_t tpr;
	char *fmt;
	va_dcl
#endif
{
	struct session *sess = (struct session *)tpr;
	struct tty *tp = NULL;
	int s, flags = TOLOG;
	va_list ap;

	if (sess && sess->s_ttyvp && ttycheckoutq(sess->s_ttyp, 0)) {
		flags |= TOTTY;
		tp = sess->s_ttyp;
	}

	KPRINTF_MUTEX_ENTER(s);

	klogpri(LOG_INFO);
	va_start(ap, fmt);
	kprintf(fmt, flags, tp, NULL, ap);
	va_end(ap);

	KPRINTF_MUTEX_EXIT(s);

	logwakeup();
}


/*
 * ttyprintf: send a message to a specific tty
 *
 * => should be used only by tty driver or anything that knows the
 *    underlying tty will not be revoked(2)'d away.  [otherwise,
 *    use tprintf]
 */
void
#ifdef __STDC__
ttyprintf(struct tty *tp, const char *fmt, ...)
#else
ttyprintf(tp, fmt, va_alist)
	struct tty *tp;
	char *fmt;
	va_dcl
#endif
{
	va_list ap;

	/* No mutex needed; going to process TTY. */
	va_start(ap, fmt);
	kprintf(fmt, TOTTY, tp, NULL, ap);
	va_end(ap);
}

#ifdef DDB

/*
 * db_printf: printf for DDB (via db_putchar)
 */

void
#ifdef __STDC__
db_printf(const char *fmt, ...)
#else
db_printf(fmt, va_alist)
	char *fmt;
	va_dcl
#endif
{
	va_list ap;

	/* No mutex needed; DDB pauses all processors. */
	va_start(ap, fmt);
	kprintf(fmt, TODDB, NULL, NULL, ap);
	va_end(ap);
}

#endif /* DDB */


/*
 * normal kernel printf functions: printf, vprintf, snprintf, vsnprintf
 */

/*
 * printf: print a message to the console and the log
 */
void
#ifdef __STDC__
printf(const char *fmt, ...)
#else
printf(fmt, va_alist)
	char *fmt;
	va_dcl
#endif
{
	va_list ap;
	int s;

	KPRINTF_MUTEX_ENTER(s);

	va_start(ap, fmt);
	kprintf(fmt, TOCONS | TOLOG, NULL, NULL, ap);
	va_end(ap);

	KPRINTF_MUTEX_EXIT(s);

	if (!panicstr)
		logwakeup();
}

/*
 * vprintf: print a message to the console and the log [already have
 *	va_alist]
 */

void
vprintf(fmt, ap)
	const char *fmt;
	va_list ap;
{
	int s;

	KPRINTF_MUTEX_ENTER(s);

	kprintf(fmt, TOCONS | TOLOG, NULL, NULL, ap);

	KPRINTF_MUTEX_EXIT(s);

	if (!panicstr)
		logwakeup();
}

/*
 * sprintf: print a message to a buffer