BSD 4.4 Lite Kernel Sources

1 files changed, 232 insertions, 0 deletions

diff --git a/sys/kern/subr_log.c b/sys/kern/subr_log.c
new file mode 100644
index 0000000..f065761
--- /dev/null
+++ b/sys/kern/subr_log.c
@@ -0,0 +1,232 @@
+/*
+ * Copyright (c) 1982, 1986, 1993
+ *	The Regents of the University of California.  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.
+ * 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_log.c	8.1 (Berkeley) 6/10/93
+ */
+
+/*
+ * Error log buffer for kernel printf's.
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/proc.h>
+#include <sys/vnode.h>
+#include <sys/ioctl.h>
+#include <sys/msgbuf.h>
+#include <sys/file.h>
+
+#define LOG_RDPRI	(PZERO + 1)
+
+#define LOG_ASYNC	0x04
+#define LOG_RDWAIT	0x08
+
+struct logsoftc {
+	int	sc_state;		/* see above for possibilities */
+	struct	selinfo sc_selp;	/* process waiting on select call */
+	int	sc_pgid;		/* process/group for async I/O */
+} logsoftc;
+
+int	log_open;			/* also used in log() */
+
+/*ARGSUSED*/
+logopen(dev, flags, mode, p)
+	dev_t dev;
+	int flags, mode;
+	struct proc *p;
+{
+	register struct msgbuf *mbp = msgbufp;
+
+	if (log_open)
+		return (EBUSY);
+	log_open = 1;
+	logsoftc.sc_pgid = p->p_pid;		/* signal process only */
+	/*
+	 * Potential race here with putchar() but since putchar should be
+	 * called by autoconf, msg_magic should be initialized by the time
+	 * we get here.
+	 */
+	if (mbp->msg_magic != MSG_MAGIC) {
+		register int i;
+
+		mbp->msg_magic = MSG_MAGIC;
+		mbp->msg_bufx = mbp->msg_bufr = 0;
+		for (i=0; i < MSG_BSIZE; i++)
+			mbp->msg_bufc[i] = 0;
+	}
+	return (0);
+}
+
+/*ARGSUSED*/
+logclose(dev, flag, mode, p)
+	dev_t dev;
+	int flag, mode;
+	struct proc *p;
+{
+
+	log_open = 0;
+	logsoftc.sc_state = 0;
+	return (0);
+}
+
+/*ARGSUSED*/
+logread(dev, uio, flag)
+	dev_t dev;
+	struct uio *uio;
+	int flag;
+{
+	register struct msgbuf *mbp = msgbufp;
+	register long l;
+	register int s;
+	int error = 0;
+
+	s = splhigh();
+	while (mbp->msg_bufr == mbp->msg_bufx) {
+		if (flag & IO_NDELAY) {
+			splx(s);
+			return (EWOULDBLOCK);
+		}
+		logsoftc.sc_state |= LOG_RDWAIT;
+		if (error = tsleep((caddr_t)mbp, LOG_RDPRI | PCATCH,
+		    "klog", 0)) {
+			splx(s);
+			return (error);
+		}
+	}
+	splx(s);
+	logsoftc.sc_state &= ~LOG_RDWAIT;
+
+	while (uio->uio_resid > 0) {
+		l = mbp->msg_bufx - mbp->msg_bufr;
+		if (l < 0)
+			l = MSG_BSIZE - mbp->msg_bufr;
+		l = min(l, uio->uio_resid);
+		if (l == 0)
+			break;
+		error = uiomove((caddr_t)&mbp->msg_bufc[mbp->msg_bufr],
+			(int)l, uio);
+		if (error)
+			break;
+		mbp->msg_bufr += l;
+		if (mbp->msg_bufr < 0 || mbp->msg_bufr >= MSG_BSIZE)
+			mbp->msg_bufr = 0;
+	}
+	return (error);
+}
+
+/*ARGSUSED*/
+logselect(dev, rw, p)
+	dev_t dev;
+	int rw;
+	struct proc *p;
+{
+	int s = splhigh();
+
+	switch (rw) {
+
+	case FREAD:
+		if (msgbufp->msg_bufr != msgbufp->msg_bufx) {
+			splx(s);
+			return (1);
+		}
+		selrecord(p, &logsoftc.sc_selp);
+		break;
+	}
+	splx(s);
+	return (0);
+}
+
+logwakeup()
+{
+	struct proc *p;
+
+	if (!log_open)
+		return;
+	selwakeup(&logsoftc.sc_selp);
+	if (logsoftc.sc_state & LOG_ASYNC) {
+		if (logsoftc.sc_pgid < 0)
+			gsignal(-logsoftc.sc_pgid, SIGIO); 
+		else if (p = pfind(logsoftc.sc_pgid))
+			psignal(p, SIGIO);
+	}
+	if (logsoftc.sc_state & LOG_RDWAIT) {
+		wakeup((caddr_t)msgbufp);
+		logsoftc.sc_state &= ~LOG_RDWAIT;
+	}
+}
+
+/*ARGSUSED*/
+logioctl(dev, com, data, flag, p)
+	dev_t dev;
+	int com;
+	caddr_t data;
+	int flag;
+	struct proc *p;
+{
+	long l;
+	int s;
+
+	switch (com) {
+
+	/* return number of characters immediately available */
+	case FIONREAD:
+		s = splhigh();
+		l = msgbufp->msg_bufx - msgbufp->msg_bufr;
+		splx(s);
+		if (l < 0)
+			l += MSG_BSIZE;
+		*(int *)data = l;
+		break;
+
+	case FIONBIO:
+		break;
+
+	case FIOASYNC:
+		if (*(int *)data)
+			logsoftc.sc_state |= LOG_ASYNC;
+		else
+			logsoftc.sc_state &= ~LOG_ASYNC;
+		break;
+
+	case TIOCSPGRP:
+		logsoftc.sc_pgid = *(int *)data;
+		break;
+
+	case TIOCGPGRP:
+		*(int *)data = logsoftc.sc_pgid;
+		break;
+
+	default:
+		return (-1);
+	}
+	return (0);
+}