/* * 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 * $Id: subr_log.c,v 1.21 1997/03/23 03:36:22 bde Exp $ */ /* * Error log buffer for kernel printf's. */ #include <sys/param.h> #include <sys/systm.h> #include <sys/conf.h> #include <sys/proc.h> #include <sys/vnode.h> #include <sys/filio.h> #include <sys/ttycom.h> #include <sys/msgbuf.h> #include <sys/fcntl.h> #include <sys/signalvar.h> #include <sys/kernel.h> #ifdef DEVFS #include <sys/devfsext.h> #endif /*DEVFS*/ #define LOG_RDPRI (PZERO + 1) #define LOG_ASYNC 0x04 #define LOG_RDWAIT 0x08 static d_open_t logopen; static d_close_t logclose; static d_read_t logread; static d_ioctl_t logioctl; static d_select_t logselect; #define CDEV_MAJOR 7 static struct cdevsw log_cdevsw = { logopen, logclose, logread, nowrite, /*7*/ logioctl, nostop, nullreset, nodevtotty,/* klog */ logselect, nommap, NULL, "log", NULL, -1 }; static 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*/ static int logopen(dev, flags, mode, p) dev_t dev; int flags, mode; struct proc *p; { if (log_open) return (EBUSY); log_open = 1; logsoftc.sc_pgid = p->p_pid; /* signal process only */ return (0); } /*ARGSUSED*/ static int logclose(dev, flag, mode, p) dev_t dev; int flag, mode; struct proc *p; { log_open = 0; logsoftc.sc_state = 0; return (0); } /*ARGSUSED*/ static int 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 >= MSG_BSIZE) mbp->msg_bufr = 0; } return (error); } /*ARGSUSED*/ static int 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); } void 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*/ static int 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 (ENOTTY); } return (0); } static log_devsw_installed = 0; #ifdef DEVFS static void *log_devfs_token; #endif static void log_drvinit(void *unused) { dev_t dev; if( ! log_devsw_installed ) { dev = makedev(CDEV_MAJOR,0); cdevsw_add(&dev,&log_cdevsw,NULL); log_devsw_installed = 1; #ifdef DEVFS log_devfs_token = devfs_add_devswf(&log_cdevsw, 0, DV_CHR, UID_ROOT, GID_WHEEL, 0600, "klog"); #endif } } SYSINIT(logdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,log_drvinit,NULL)