subr_log.c revision 32726
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 3412521Sjulian * $Id: subr_log.c,v 1.25 1997/10/28 15:58:21 bde Exp $ 351541Srgrimes */ 361541Srgrimes 371541Srgrimes/* 381541Srgrimes * Error log buffer for kernel printf's. 391541Srgrimes */ 401541Srgrimes 411541Srgrimes#include "opt_devfs.h" 421541Srgrimes 431541Srgrimes#include <sys/param.h> 441541Srgrimes#include <sys/systm.h> 451541Srgrimes#include <sys/conf.h> 461541Srgrimes#include <sys/proc.h> 471541Srgrimes#include <sys/vnode.h> 483308Sphk#include <sys/filio.h> 491541Srgrimes#include <sys/ttycom.h> 5012517Sjulian#include <sys/msgbuf.h> 5112517Sjulian#include <sys/signalvar.h> 5212517Sjulian#include <sys/kernel.h> 5312517Sjulian#include <sys/poll.h> 5412517Sjulian#ifdef DEVFS 5512517Sjulian#include <sys/devfsext.h> 5612517Sjulian#endif /*DEVFS*/ 5712517Sjulian 5812517Sjulian#define LOG_RDPRI (PZERO + 1) 591541Srgrimes 601541Srgrimes#define LOG_ASYNC 0x04 611541Srgrimes#define LOG_RDWAIT 0x08 621541Srgrimes 631541Srgrimesstatic d_open_t logopen; 641541Srgrimesstatic d_close_t logclose; 651541Srgrimesstatic d_read_t logread; 661541Srgrimesstatic d_ioctl_t logioctl; 671541Srgrimesstatic d_poll_t logpoll; 681541Srgrimes 691541Srgrimes#define CDEV_MAJOR 7 701541Srgrimesstatic struct cdevsw log_cdevsw = 711541Srgrimes { logopen, logclose, logread, nowrite, /*7*/ 721541Srgrimes logioctl, nostop, nullreset, nodevtotty,/* klog */ 731549Srgrimes logpoll, nommap, NULL, "log", NULL, -1 }; 741541Srgrimes 751541Srgrimesstatic struct logsoftc { 761541Srgrimes int sc_state; /* see above for possibilities */ 771541Srgrimes struct selinfo sc_selp; /* process waiting on select call */ 781541Srgrimes int sc_pgid; /* process/group for async I/O */ 791541Srgrimes} logsoftc; 801541Srgrimes 811541Srgrimesint log_open; /* also used in log() */ 821541Srgrimes 831541Srgrimes/*ARGSUSED*/ 841541Srgrimesstatic int 851541Srgrimeslogopen(dev, flags, mode, p) 861541Srgrimes dev_t dev; 871549Srgrimes int flags, mode; 881541Srgrimes struct proc *p; 891541Srgrimes{ 901541Srgrimes if (log_open) 911541Srgrimes return (EBUSY); 921541Srgrimes log_open = 1; 931541Srgrimes logsoftc.sc_pgid = p->p_pid; /* signal process only */ 941541Srgrimes return (0); 951541Srgrimes} 961541Srgrimes 971541Srgrimes/*ARGSUSED*/ 981541Srgrimesstatic int 991541Srgrimeslogclose(dev, flag, mode, p) 1001549Srgrimes dev_t dev; 1011541Srgrimes int flag, mode; 1021541Srgrimes struct proc *p; 1031541Srgrimes{ 1041541Srgrimes 1051541Srgrimes log_open = 0; 1061541Srgrimes logsoftc.sc_state = 0; 1071541Srgrimes return (0); 1081541Srgrimes} 1091541Srgrimes 1101541Srgrimes/*ARGSUSED*/ 1111541Srgrimesstatic int 1121541Srgrimeslogread(dev, uio, flag) 1131541Srgrimes dev_t dev; 1141541Srgrimes struct uio *uio; 1151541Srgrimes int flag; 1161541Srgrimes{ 1171541Srgrimes register struct msgbuf *mbp = msgbufp; 1183098Sphk register long l; 1193098Sphk register int s; 1201541Srgrimes int error = 0; 1211541Srgrimes 1221541Srgrimes s = splhigh(); 1231541Srgrimes while (mbp->msg_bufr == mbp->msg_bufx) { 1241541Srgrimes if (flag & IO_NDELAY) { 1251541Srgrimes splx(s); 1261541Srgrimes return (EWOULDBLOCK); 1271541Srgrimes } 1281541Srgrimes logsoftc.sc_state |= LOG_RDWAIT; 1291541Srgrimes if ((error = tsleep((caddr_t)mbp, LOG_RDPRI | PCATCH, 1301541Srgrimes "klog", 0))) { 1311541Srgrimes splx(s); 1321541Srgrimes return (error); 1331541Srgrimes } 1341541Srgrimes } 1351541Srgrimes splx(s); 1361541Srgrimes logsoftc.sc_state &= ~LOG_RDWAIT; 1371541Srgrimes 1381541Srgrimes while (uio->uio_resid > 0) { 1399979Sdg l = mbp->msg_bufx - mbp->msg_bufr; 1401541Srgrimes if (l < 0) 1411541Srgrimes l = MSG_BSIZE - mbp->msg_bufr; 1421541Srgrimes l = min(l, uio->uio_resid); 1431541Srgrimes if (l == 0) 1441541Srgrimes break; 1451541Srgrimes error = uiomove((caddr_t)&mbp->msg_bufc[mbp->msg_bufr], 1461549Srgrimes (int)l, uio); 1471541Srgrimes if (error) 1481541Srgrimes break; 1491541Srgrimes mbp->msg_bufr += l; 1501541Srgrimes if (mbp->msg_bufr >= MSG_BSIZE) 1511541Srgrimes mbp->msg_bufr = 0; 1521541Srgrimes } 1531541Srgrimes return (error); 1541541Srgrimes} 1551541Srgrimes 1561541Srgrimes/*ARGSUSED*/ 1571541Srgrimesstatic int 1581541Srgrimeslogpoll(dev, events, p) 1591541Srgrimes dev_t dev; 1601541Srgrimes int events; 1611541Srgrimes struct proc *p; 1621541Srgrimes{ 1631541Srgrimes int s; 1641541Srgrimes int revents = 0; 1651541Srgrimes 1661541Srgrimes s = splhigh(); 1671541Srgrimes 1681549Srgrimes if (events & (POLLIN | POLLRDNORM)) 1691541Srgrimes if (msgbufp->msg_bufr != msgbufp->msg_bufx) 1701541Srgrimes revents |= events & (POLLIN | POLLRDNORM); 1711541Srgrimes else 1721541Srgrimes selrecord(p, &logsoftc.sc_selp); 1731541Srgrimes 1741541Srgrimes splx(s); 1751541Srgrimes return (revents); 1761541Srgrimes} 1771541Srgrimes 1788876Srgrimesvoid 1793098Sphklogwakeup() 1801541Srgrimes{ 1811541Srgrimes struct proc *p; 1821541Srgrimes 1831541Srgrimes if (!log_open) 1841541Srgrimes return; 1851541Srgrimes selwakeup(&logsoftc.sc_selp); 1861541Srgrimes if (logsoftc.sc_state & LOG_ASYNC) { 1871541Srgrimes if (logsoftc.sc_pgid < 0) 1881541Srgrimes gsignal(-logsoftc.sc_pgid, SIGIO); 1891549Srgrimes else if ((p = pfind(logsoftc.sc_pgid))) 1901541Srgrimes psignal(p, SIGIO); 1911541Srgrimes } 1921541Srgrimes if (logsoftc.sc_state & LOG_RDWAIT) { 1931541Srgrimes wakeup((caddr_t)msgbufp); 1941541Srgrimes logsoftc.sc_state &= ~LOG_RDWAIT; 1951541Srgrimes } 1961541Srgrimes} 1971541Srgrimes 1981541Srgrimes/*ARGSUSED*/ 1991541Srgrimesstatic int 2001541Srgrimeslogioctl(dev, com, data, flag, p) 2011541Srgrimes dev_t dev; 2021541Srgrimes int com; 2031541Srgrimes caddr_t data; 2041541Srgrimes int flag; 2051541Srgrimes struct proc *p; 2061541Srgrimes{ 2071541Srgrimes long l; 2081541Srgrimes int s; 2091541Srgrimes 2101541Srgrimes switch (com) { 2111541Srgrimes 2121541Srgrimes /* return number of characters immediately available */ 2131541Srgrimes case FIONREAD: 2141541Srgrimes s = splhigh(); 2151541Srgrimes l = msgbufp->msg_bufx - msgbufp->msg_bufr; 2161541Srgrimes splx(s); 2171541Srgrimes if (l < 0) 2181541Srgrimes l += MSG_BSIZE; 2191541Srgrimes *(int *)data = l; 2201541Srgrimes break; 2211541Srgrimes 2221541Srgrimes case FIONBIO: 2231541Srgrimes break; 2241541Srgrimes 2251541Srgrimes case FIOASYNC: 2261541Srgrimes if (*(int *)data) 2271541Srgrimes logsoftc.sc_state |= LOG_ASYNC; 2281541Srgrimes else 2291541Srgrimes logsoftc.sc_state &= ~LOG_ASYNC; 2301541Srgrimes break; 2318161Sjkh 2321541Srgrimes case TIOCSPGRP: 2331541Srgrimes logsoftc.sc_pgid = *(int *)data; 2341541Srgrimes break; 23512517Sjulian 23612517Sjulian case TIOCGPGRP: 23712517Sjulian *(int *)data = logsoftc.sc_pgid; 23812517Sjulian break; 23912517Sjulian 24012517Sjulian default: 24112517Sjulian return (ENOTTY); 24212517Sjulian } 24312517Sjulian return (0); 24412517Sjulian} 24512517Sjulian 24612517Sjulianstatic log_devsw_installed = 0; 24712517Sjulian#ifdef DEVFS 24812517Sjulianstatic void *log_devfs_token; 24912517Sjulian#endif 25012517Sjulian 25112517Sjulianstatic void log_drvinit __P((void *unused)); 25212517Sjulianstatic void 25312517Sjulianlog_drvinit(unused) 25412517Sjulian void *unused; 25512517Sjulian{ 25612517Sjulian dev_t dev; 25712517Sjulian 25812517Sjulian if( ! log_devsw_installed ) { 25912517Sjulian dev = makedev(CDEV_MAJOR,0); 26012521Sjulian cdevsw_add(&dev,&log_cdevsw,NULL); 26112517Sjulian log_devsw_installed = 1; 26212517Sjulian#ifdef DEVFS 26312517Sjulian log_devfs_token = devfs_add_devswf(&log_cdevsw, 0, DV_CHR, 26412517Sjulian UID_ROOT, GID_WHEEL, 0600, 26512517Sjulian "klog"); 26612517Sjulian#endif 26712517Sjulian } 268} 269 270SYSINIT(logdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,log_drvinit,NULL) 271 272 273