subr_log.c revision 12678
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 3412678Sphk * $Id: subr_log.c,v 1.14 1995/12/08 11:17:06 julian Exp $ 351541Srgrimes */ 361541Srgrimes 371541Srgrimes/* 381541Srgrimes * Error log buffer for kernel printf's. 391541Srgrimes */ 401541Srgrimes 411541Srgrimes#include <sys/param.h> 421541Srgrimes#include <sys/systm.h> 4312577Sbde#include <sys/conf.h> 441541Srgrimes#include <sys/proc.h> 451541Srgrimes#include <sys/vnode.h> 461541Srgrimes#include <sys/ioctl.h> 471541Srgrimes#include <sys/msgbuf.h> 481541Srgrimes#include <sys/file.h> 493308Sphk#include <sys/signalvar.h> 5012517Sjulian#include <sys/kernel.h> 5112517Sjulian#ifdef DEVFS 5212517Sjulian#include <sys/devfsext.h> 5312517Sjulian#endif /*DEVFS*/ 5412517Sjulian 551541Srgrimes#define LOG_RDPRI (PZERO + 1) 561541Srgrimes 571541Srgrimes#define LOG_ASYNC 0x04 581541Srgrimes#define LOG_RDWAIT 0x08 591541Srgrimes 6012675Sjulianstatic d_open_t logopen; 6112675Sjulianstatic d_close_t logclose; 6212675Sjulianstatic d_read_t logread; 6312675Sjulianstatic d_ioctl_t logioctl; 6412675Sjulianstatic d_select_t logselect; 6512675Sjulian 6612675Sjulian#define CDEV_MAJOR 7 6712678Sphkstatic struct cdevsw log_cdevsw = 6812675Sjulian { logopen, logclose, logread, nowrite, /*7*/ 6912675Sjulian logioctl, nostop, nullreset, nodevtotty,/* klog */ 7012675Sjulian logselect, nommap, NULL, "log", NULL, -1 }; 7112675Sjulian 721541Srgrimesstruct logsoftc { 731541Srgrimes int sc_state; /* see above for possibilities */ 741541Srgrimes struct selinfo sc_selp; /* process waiting on select call */ 751541Srgrimes int sc_pgid; /* process/group for async I/O */ 761541Srgrimes} logsoftc; 771541Srgrimes 781541Srgrimesint log_open; /* also used in log() */ 791541Srgrimes 801541Srgrimes/*ARGSUSED*/ 8112675Sjulianstatic int 821541Srgrimeslogopen(dev, flags, mode, p) 831541Srgrimes dev_t dev; 841541Srgrimes int flags, mode; 851541Srgrimes struct proc *p; 861541Srgrimes{ 871541Srgrimes if (log_open) 881541Srgrimes return (EBUSY); 891541Srgrimes log_open = 1; 901541Srgrimes logsoftc.sc_pgid = p->p_pid; /* signal process only */ 911541Srgrimes return (0); 921541Srgrimes} 931541Srgrimes 941541Srgrimes/*ARGSUSED*/ 9512675Sjulianstatic int 961541Srgrimeslogclose(dev, flag, mode, p) 971541Srgrimes dev_t dev; 981541Srgrimes int flag, mode; 991541Srgrimes struct proc *p; 1001541Srgrimes{ 1011541Srgrimes 1021541Srgrimes log_open = 0; 1031541Srgrimes logsoftc.sc_state = 0; 1041541Srgrimes return (0); 1051541Srgrimes} 1061541Srgrimes 1071541Srgrimes/*ARGSUSED*/ 10812675Sjulianstatic int 1091541Srgrimeslogread(dev, uio, flag) 1101541Srgrimes dev_t dev; 1111541Srgrimes struct uio *uio; 1121541Srgrimes int flag; 1131541Srgrimes{ 1141541Srgrimes register struct msgbuf *mbp = msgbufp; 1151541Srgrimes register long l; 1161541Srgrimes register int s; 1171541Srgrimes int error = 0; 1181541Srgrimes 1191541Srgrimes s = splhigh(); 1201541Srgrimes while (mbp->msg_bufr == mbp->msg_bufx) { 1211541Srgrimes if (flag & IO_NDELAY) { 1221541Srgrimes splx(s); 1231541Srgrimes return (EWOULDBLOCK); 1241541Srgrimes } 1251541Srgrimes logsoftc.sc_state |= LOG_RDWAIT; 1263098Sphk if ((error = tsleep((caddr_t)mbp, LOG_RDPRI | PCATCH, 1273098Sphk "klog", 0))) { 1281541Srgrimes splx(s); 1291541Srgrimes return (error); 1301541Srgrimes } 1311541Srgrimes } 1321541Srgrimes splx(s); 1331541Srgrimes logsoftc.sc_state &= ~LOG_RDWAIT; 1341541Srgrimes 1351541Srgrimes while (uio->uio_resid > 0) { 1361541Srgrimes l = mbp->msg_bufx - mbp->msg_bufr; 1371541Srgrimes if (l < 0) 1381541Srgrimes l = MSG_BSIZE - mbp->msg_bufr; 1391541Srgrimes l = min(l, uio->uio_resid); 1401541Srgrimes if (l == 0) 1411541Srgrimes break; 1421541Srgrimes error = uiomove((caddr_t)&mbp->msg_bufc[mbp->msg_bufr], 1431541Srgrimes (int)l, uio); 1441541Srgrimes if (error) 1451541Srgrimes break; 1461541Srgrimes mbp->msg_bufr += l; 1479979Sdg if (mbp->msg_bufr >= MSG_BSIZE) 1481541Srgrimes mbp->msg_bufr = 0; 1491541Srgrimes } 1501541Srgrimes return (error); 1511541Srgrimes} 1521541Srgrimes 1531541Srgrimes/*ARGSUSED*/ 15412675Sjulianstatic int 1551541Srgrimeslogselect(dev, rw, p) 1561541Srgrimes dev_t dev; 1571541Srgrimes int rw; 1581541Srgrimes struct proc *p; 1591541Srgrimes{ 1601541Srgrimes int s = splhigh(); 1611541Srgrimes 1621541Srgrimes switch (rw) { 1631541Srgrimes 1641541Srgrimes case FREAD: 1651541Srgrimes if (msgbufp->msg_bufr != msgbufp->msg_bufx) { 1661541Srgrimes splx(s); 1671541Srgrimes return (1); 1681541Srgrimes } 1691541Srgrimes selrecord(p, &logsoftc.sc_selp); 1701541Srgrimes break; 1711541Srgrimes } 1721541Srgrimes splx(s); 1731541Srgrimes return (0); 1741541Srgrimes} 1751541Srgrimes 1761549Srgrimesvoid 1771541Srgrimeslogwakeup() 1781541Srgrimes{ 1791541Srgrimes struct proc *p; 1801541Srgrimes 1811541Srgrimes if (!log_open) 1821541Srgrimes return; 1831541Srgrimes selwakeup(&logsoftc.sc_selp); 1841541Srgrimes if (logsoftc.sc_state & LOG_ASYNC) { 1851541Srgrimes if (logsoftc.sc_pgid < 0) 1868876Srgrimes gsignal(-logsoftc.sc_pgid, SIGIO); 1873098Sphk else if ((p = pfind(logsoftc.sc_pgid))) 1881541Srgrimes psignal(p, SIGIO); 1891541Srgrimes } 1901541Srgrimes if (logsoftc.sc_state & LOG_RDWAIT) { 1911541Srgrimes wakeup((caddr_t)msgbufp); 1921541Srgrimes logsoftc.sc_state &= ~LOG_RDWAIT; 1931541Srgrimes } 1941541Srgrimes} 1951541Srgrimes 1961541Srgrimes/*ARGSUSED*/ 19712675Sjulianstatic int 1981541Srgrimeslogioctl(dev, com, data, flag, p) 1991541Srgrimes dev_t dev; 2001541Srgrimes int com; 2011541Srgrimes caddr_t data; 2021541Srgrimes int flag; 2031541Srgrimes struct proc *p; 2041541Srgrimes{ 2051541Srgrimes long l; 2061541Srgrimes int s; 2071541Srgrimes 2081541Srgrimes switch (com) { 2091541Srgrimes 2101541Srgrimes /* return number of characters immediately available */ 2111541Srgrimes case FIONREAD: 2121541Srgrimes s = splhigh(); 2131541Srgrimes l = msgbufp->msg_bufx - msgbufp->msg_bufr; 2141541Srgrimes splx(s); 2151541Srgrimes if (l < 0) 2161541Srgrimes l += MSG_BSIZE; 2171541Srgrimes *(int *)data = l; 2181541Srgrimes break; 2191541Srgrimes 2201541Srgrimes case FIONBIO: 2211541Srgrimes break; 2221541Srgrimes 2231541Srgrimes case FIOASYNC: 2241541Srgrimes if (*(int *)data) 2251541Srgrimes logsoftc.sc_state |= LOG_ASYNC; 2261541Srgrimes else 2271541Srgrimes logsoftc.sc_state &= ~LOG_ASYNC; 2281541Srgrimes break; 2291541Srgrimes 2301541Srgrimes case TIOCSPGRP: 2311541Srgrimes logsoftc.sc_pgid = *(int *)data; 2321541Srgrimes break; 2331541Srgrimes 2341541Srgrimes case TIOCGPGRP: 2351541Srgrimes *(int *)data = logsoftc.sc_pgid; 2361541Srgrimes break; 2371541Srgrimes 2381541Srgrimes default: 2398161Sjkh return (ENOTTY); 2401541Srgrimes } 2411541Srgrimes return (0); 2421541Srgrimes} 24312517Sjulian 24412517Sjulianstatic log_devsw_installed = 0; 24512675Sjulianstatic void *log_devfs_token; 24612517Sjulian 24712675Sjulianstatic void 24812675Sjulianlog_drvinit(void *unused) 24912517Sjulian{ 25012517Sjulian dev_t dev; 25112517Sjulian 25212517Sjulian if( ! log_devsw_installed ) { 25312517Sjulian dev = makedev(CDEV_MAJOR,0); 25412517Sjulian cdevsw_add(&dev,&log_cdevsw,NULL); 25512517Sjulian log_devsw_installed = 1; 25612517Sjulian#ifdef DEVFS 25712675Sjulian log_devfs_token = devfs_add_devsw( 25812675Sjulian "/", "log", &log_cdevsw, 0, DV_CHR, 0, 0, 0600); 25912521Sjulian#endif 26012517Sjulian } 26112517Sjulian} 26212517Sjulian 26312517SjulianSYSINIT(logdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,log_drvinit,NULL) 26412517Sjulian 26512517Sjulian 266