subr_log.c revision 36179
11541Srgrimes/* 21541Srgrimes * Copyright (c) 1982, 1986, 1993 31541Srgrimes * The Regents of the University of California. All rights reserved. 41541Srgrimes * 51541Srgrimes * Redistribution and use in source and binary forms, with or without 61541Srgrimes * modification, are permitted provided that the following conditions 71541Srgrimes * are met: 81541Srgrimes * 1. Redistributions of source code must retain the above copyright 91541Srgrimes * notice, this list of conditions and the following disclaimer. 101541Srgrimes * 2. Redistributions in binary form must reproduce the above copyright 111541Srgrimes * notice, this list of conditions and the following disclaimer in the 121541Srgrimes * documentation and/or other materials provided with the distribution. 131541Srgrimes * 3. All advertising materials mentioning features or use of this software 141541Srgrimes * must display the following acknowledgement: 151541Srgrimes * This product includes software developed by the University of 161541Srgrimes * California, Berkeley and its contributors. 171541Srgrimes * 4. Neither the name of the University nor the names of its contributors 181541Srgrimes * may be used to endorse or promote products derived from this software 191541Srgrimes * without specific prior written permission. 201541Srgrimes * 211541Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 221541Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 231541Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 241541Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 251541Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 261541Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 271541Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 281541Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 291541Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 301541Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 311541Srgrimes * SUCH DAMAGE. 321541Srgrimes * 331541Srgrimes * @(#)subr_log.c 8.1 (Berkeley) 6/10/93 3436179Sphk * $Id: subr_log.c,v 1.27 1998/02/20 13:46:56 bde Exp $ 351541Srgrimes */ 361541Srgrimes 371541Srgrimes/* 381541Srgrimes * Error log buffer for kernel printf's. 391541Srgrimes */ 401541Srgrimes 4132726Seivind#include "opt_devfs.h" 4236179Sphk#include "opt_msgbuf.h" 4332726Seivind 441541Srgrimes#include <sys/param.h> 451541Srgrimes#include <sys/systm.h> 4612577Sbde#include <sys/conf.h> 471541Srgrimes#include <sys/proc.h> 481541Srgrimes#include <sys/vnode.h> 4924206Sbde#include <sys/filio.h> 5024206Sbde#include <sys/ttycom.h> 511541Srgrimes#include <sys/msgbuf.h> 523308Sphk#include <sys/signalvar.h> 5312517Sjulian#include <sys/kernel.h> 5429357Speter#include <sys/poll.h> 5512517Sjulian#ifdef DEVFS 5612517Sjulian#include <sys/devfsext.h> 5712517Sjulian#endif /*DEVFS*/ 5812517Sjulian 591541Srgrimes#define LOG_RDPRI (PZERO + 1) 601541Srgrimes 611541Srgrimes#define LOG_ASYNC 0x04 621541Srgrimes#define LOG_RDWAIT 0x08 631541Srgrimes 6412675Sjulianstatic d_open_t logopen; 6512675Sjulianstatic d_close_t logclose; 6612675Sjulianstatic d_read_t logread; 6712675Sjulianstatic d_ioctl_t logioctl; 6829357Speterstatic d_poll_t logpoll; 6912675Sjulian 7012675Sjulian#define CDEV_MAJOR 7 7112678Sphkstatic struct cdevsw log_cdevsw = 7212675Sjulian { logopen, logclose, logread, nowrite, /*7*/ 7312675Sjulian logioctl, nostop, nullreset, nodevtotty,/* klog */ 7429357Speter logpoll, nommap, NULL, "log", NULL, -1 }; 7512675Sjulian 7612819Sphkstatic struct logsoftc { 771541Srgrimes int sc_state; /* see above for possibilities */ 781541Srgrimes struct selinfo sc_selp; /* process waiting on select call */ 791541Srgrimes int sc_pgid; /* process/group for async I/O */ 801541Srgrimes} logsoftc; 811541Srgrimes 821541Srgrimesint log_open; /* also used in log() */ 831541Srgrimes 841541Srgrimes/*ARGSUSED*/ 8512675Sjulianstatic int 861541Srgrimeslogopen(dev, flags, mode, p) 871541Srgrimes dev_t dev; 881541Srgrimes int flags, mode; 891541Srgrimes struct proc *p; 901541Srgrimes{ 911541Srgrimes if (log_open) 921541Srgrimes return (EBUSY); 931541Srgrimes log_open = 1; 941541Srgrimes logsoftc.sc_pgid = p->p_pid; /* signal process only */ 951541Srgrimes return (0); 961541Srgrimes} 971541Srgrimes 981541Srgrimes/*ARGSUSED*/ 9912675Sjulianstatic int 1001541Srgrimeslogclose(dev, flag, mode, p) 1011541Srgrimes dev_t dev; 1021541Srgrimes int flag, mode; 1031541Srgrimes struct proc *p; 1041541Srgrimes{ 1051541Srgrimes 1061541Srgrimes log_open = 0; 1071541Srgrimes logsoftc.sc_state = 0; 1081541Srgrimes return (0); 1091541Srgrimes} 1101541Srgrimes 1111541Srgrimes/*ARGSUSED*/ 11212675Sjulianstatic int 1131541Srgrimeslogread(dev, uio, flag) 1141541Srgrimes dev_t dev; 1151541Srgrimes struct uio *uio; 1161541Srgrimes int flag; 1171541Srgrimes{ 1181541Srgrimes register struct msgbuf *mbp = msgbufp; 1191541Srgrimes register long l; 1201541Srgrimes register int s; 1211541Srgrimes int error = 0; 1221541Srgrimes 1231541Srgrimes s = splhigh(); 1241541Srgrimes while (mbp->msg_bufr == mbp->msg_bufx) { 1251541Srgrimes if (flag & IO_NDELAY) { 1261541Srgrimes splx(s); 1271541Srgrimes return (EWOULDBLOCK); 1281541Srgrimes } 1291541Srgrimes logsoftc.sc_state |= LOG_RDWAIT; 1303098Sphk if ((error = tsleep((caddr_t)mbp, LOG_RDPRI | PCATCH, 1313098Sphk "klog", 0))) { 1321541Srgrimes splx(s); 1331541Srgrimes return (error); 1341541Srgrimes } 1351541Srgrimes } 1361541Srgrimes splx(s); 1371541Srgrimes logsoftc.sc_state &= ~LOG_RDWAIT; 1381541Srgrimes 1391541Srgrimes while (uio->uio_resid > 0) { 1401541Srgrimes l = mbp->msg_bufx - mbp->msg_bufr; 1411541Srgrimes if (l < 0) 14236179Sphk l = mbp->msg_size - mbp->msg_bufr; 1431541Srgrimes l = min(l, uio->uio_resid); 1441541Srgrimes if (l == 0) 1451541Srgrimes break; 14636179Sphk error = uiomove((caddr_t)msgbufp->msg_ptr + mbp->msg_bufr, 14736179Sphk (int)l, uio); 1481541Srgrimes if (error) 1491541Srgrimes break; 1501541Srgrimes mbp->msg_bufr += l; 15136179Sphk if (mbp->msg_bufr >= mbp->msg_size) 1521541Srgrimes mbp->msg_bufr = 0; 1531541Srgrimes } 1541541Srgrimes return (error); 1551541Srgrimes} 1561541Srgrimes 1571541Srgrimes/*ARGSUSED*/ 15812675Sjulianstatic int 15929357Speterlogpoll(dev, events, p) 1601541Srgrimes dev_t dev; 16129357Speter int events; 1621541Srgrimes struct proc *p; 1631541Srgrimes{ 16429357Speter int s; 16529357Speter int revents = 0; 1661541Srgrimes 16729357Speter s = splhigh(); 1681541Srgrimes 16929357Speter if (events & (POLLIN | POLLRDNORM)) 17029357Speter if (msgbufp->msg_bufr != msgbufp->msg_bufx) 17129357Speter revents |= events & (POLLIN | POLLRDNORM); 17229357Speter else 17329357Speter selrecord(p, &logsoftc.sc_selp); 17429357Speter 1751541Srgrimes splx(s); 17629357Speter return (revents); 1771541Srgrimes} 1781541Srgrimes 1791549Srgrimesvoid 1801541Srgrimeslogwakeup() 1811541Srgrimes{ 1821541Srgrimes struct proc *p; 1831541Srgrimes 1841541Srgrimes if (!log_open) 1851541Srgrimes return; 1861541Srgrimes selwakeup(&logsoftc.sc_selp); 1871541Srgrimes if (logsoftc.sc_state & LOG_ASYNC) { 1881541Srgrimes if (logsoftc.sc_pgid < 0) 1898876Srgrimes gsignal(-logsoftc.sc_pgid, SIGIO); 1903098Sphk else if ((p = pfind(logsoftc.sc_pgid))) 1911541Srgrimes psignal(p, SIGIO); 1921541Srgrimes } 1931541Srgrimes if (logsoftc.sc_state & LOG_RDWAIT) { 1941541Srgrimes wakeup((caddr_t)msgbufp); 1951541Srgrimes logsoftc.sc_state &= ~LOG_RDWAIT; 1961541Srgrimes } 1971541Srgrimes} 1981541Srgrimes 1991541Srgrimes/*ARGSUSED*/ 20012675Sjulianstatic int 2011541Srgrimeslogioctl(dev, com, data, flag, p) 2021541Srgrimes dev_t dev; 2031541Srgrimes int com; 2041541Srgrimes caddr_t data; 2051541Srgrimes int flag; 2061541Srgrimes struct proc *p; 2071541Srgrimes{ 2081541Srgrimes long l; 2091541Srgrimes int s; 2101541Srgrimes 2111541Srgrimes switch (com) { 2121541Srgrimes 2131541Srgrimes /* return number of characters immediately available */ 2141541Srgrimes case FIONREAD: 2151541Srgrimes s = splhigh(); 2161541Srgrimes l = msgbufp->msg_bufx - msgbufp->msg_bufr; 2171541Srgrimes splx(s); 2181541Srgrimes if (l < 0) 21936179Sphk l += msgbufp->msg_size; 2201541Srgrimes *(int *)data = l; 2211541Srgrimes break; 2221541Srgrimes 2231541Srgrimes case FIONBIO: 2241541Srgrimes break; 2251541Srgrimes 2261541Srgrimes case FIOASYNC: 2271541Srgrimes if (*(int *)data) 2281541Srgrimes logsoftc.sc_state |= LOG_ASYNC; 2291541Srgrimes else 2301541Srgrimes logsoftc.sc_state &= ~LOG_ASYNC; 2311541Srgrimes break; 2321541Srgrimes 2331541Srgrimes case TIOCSPGRP: 2341541Srgrimes logsoftc.sc_pgid = *(int *)data; 2351541Srgrimes break; 2361541Srgrimes 2371541Srgrimes case TIOCGPGRP: 2381541Srgrimes *(int *)data = logsoftc.sc_pgid; 2391541Srgrimes break; 2401541Srgrimes 2411541Srgrimes default: 2428161Sjkh return (ENOTTY); 2431541Srgrimes } 2441541Srgrimes return (0); 2451541Srgrimes} 24612517Sjulian 24733679Sbdestatic int log_devsw_installed; 24817040Swollman#ifdef DEVFS 24912675Sjulianstatic void *log_devfs_token; 25017040Swollman#endif 25112517Sjulian 25229506Sbdestatic void log_drvinit __P((void *unused)); 25312675Sjulianstatic void 25429506Sbdelog_drvinit(unused) 25529506Sbde void *unused; 25612517Sjulian{ 25712517Sjulian dev_t dev; 25812517Sjulian 25912517Sjulian if( ! log_devsw_installed ) { 26012517Sjulian dev = makedev(CDEV_MAJOR,0); 26112517Sjulian cdevsw_add(&dev,&log_cdevsw,NULL); 26212517Sjulian log_devsw_installed = 1; 26312517Sjulian#ifdef DEVFS 26414851Sbde log_devfs_token = devfs_add_devswf(&log_cdevsw, 0, DV_CHR, 26514851Sbde UID_ROOT, GID_WHEEL, 0600, 26614851Sbde "klog"); 26712521Sjulian#endif 26812517Sjulian } 26912517Sjulian} 27012517Sjulian 27112517SjulianSYSINIT(logdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,log_drvinit,NULL) 27212517Sjulian 27312517Sjulian 274