subr_log.c revision 50254
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 3450254Sphk * $Id: subr_log.c,v 1.36 1999/05/31 11:27:35 phk 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> 4624206Sbde#include <sys/filio.h> 4724206Sbde#include <sys/ttycom.h> 481541Srgrimes#include <sys/msgbuf.h> 493308Sphk#include <sys/signalvar.h> 5012517Sjulian#include <sys/kernel.h> 5129357Speter#include <sys/poll.h> 5241086Struckman#include <sys/filedesc.h> 5312517Sjulian 541541Srgrimes#define LOG_RDPRI (PZERO + 1) 551541Srgrimes 561541Srgrimes#define LOG_ASYNC 0x04 571541Srgrimes#define LOG_RDWAIT 0x08 581541Srgrimes 5912675Sjulianstatic d_open_t logopen; 6012675Sjulianstatic d_close_t logclose; 6112675Sjulianstatic d_read_t logread; 6212675Sjulianstatic d_ioctl_t logioctl; 6329357Speterstatic d_poll_t logpoll; 6412675Sjulian 6512675Sjulian#define CDEV_MAJOR 7 6647625Sphkstatic struct cdevsw log_cdevsw = { 6747625Sphk /* open */ logopen, 6847625Sphk /* close */ logclose, 6947625Sphk /* read */ logread, 7047625Sphk /* write */ nowrite, 7147625Sphk /* ioctl */ logioctl, 7247625Sphk /* stop */ nostop, 7347625Sphk /* reset */ noreset, 7447625Sphk /* devtotty */ nodevtotty, 7547625Sphk /* poll */ logpoll, 7647625Sphk /* mmap */ nommap, 7747625Sphk /* strategy */ nostrategy, 7847625Sphk /* name */ "log", 7947625Sphk /* parms */ noparms, 8047625Sphk /* maj */ CDEV_MAJOR, 8147625Sphk /* dump */ nodump, 8247625Sphk /* psize */ nopsize, 8347625Sphk /* flags */ 0, 8447625Sphk /* maxio */ 0, 8547625Sphk /* bmaj */ -1 8647625Sphk}; 8712675Sjulian 8812819Sphkstatic struct logsoftc { 891541Srgrimes int sc_state; /* see above for possibilities */ 901541Srgrimes struct selinfo sc_selp; /* process waiting on select call */ 9141087Struckman struct sigio *sc_sigio; /* information for async I/O */ 921541Srgrimes} logsoftc; 931541Srgrimes 941541Srgrimesint log_open; /* also used in log() */ 951541Srgrimes 961541Srgrimes/*ARGSUSED*/ 9712675Sjulianstatic int 981541Srgrimeslogopen(dev, flags, mode, p) 991541Srgrimes dev_t dev; 1001541Srgrimes int flags, mode; 1011541Srgrimes struct proc *p; 1021541Srgrimes{ 1031541Srgrimes if (log_open) 1041541Srgrimes return (EBUSY); 1051541Srgrimes log_open = 1; 10641086Struckman fsetown(p->p_pid, &logsoftc.sc_sigio); /* signal process only */ 1071541Srgrimes return (0); 1081541Srgrimes} 1091541Srgrimes 1101541Srgrimes/*ARGSUSED*/ 11112675Sjulianstatic int 1121541Srgrimeslogclose(dev, flag, mode, p) 1131541Srgrimes dev_t dev; 1141541Srgrimes int flag, mode; 1151541Srgrimes struct proc *p; 1161541Srgrimes{ 1171541Srgrimes 1181541Srgrimes log_open = 0; 1191541Srgrimes logsoftc.sc_state = 0; 12041086Struckman funsetown(logsoftc.sc_sigio); 1211541Srgrimes return (0); 1221541Srgrimes} 1231541Srgrimes 1241541Srgrimes/*ARGSUSED*/ 12512675Sjulianstatic int 1261541Srgrimeslogread(dev, uio, flag) 1271541Srgrimes dev_t dev; 1281541Srgrimes struct uio *uio; 1291541Srgrimes int flag; 1301541Srgrimes{ 1311541Srgrimes register struct msgbuf *mbp = msgbufp; 1321541Srgrimes register long l; 1331541Srgrimes register int s; 1341541Srgrimes int error = 0; 1351541Srgrimes 1361541Srgrimes s = splhigh(); 1371541Srgrimes while (mbp->msg_bufr == mbp->msg_bufx) { 1381541Srgrimes if (flag & IO_NDELAY) { 1391541Srgrimes splx(s); 1401541Srgrimes return (EWOULDBLOCK); 1411541Srgrimes } 1421541Srgrimes logsoftc.sc_state |= LOG_RDWAIT; 1433098Sphk if ((error = tsleep((caddr_t)mbp, LOG_RDPRI | PCATCH, 1443098Sphk "klog", 0))) { 1451541Srgrimes splx(s); 1461541Srgrimes return (error); 1471541Srgrimes } 1481541Srgrimes } 1491541Srgrimes splx(s); 1501541Srgrimes logsoftc.sc_state &= ~LOG_RDWAIT; 1511541Srgrimes 1521541Srgrimes while (uio->uio_resid > 0) { 1531541Srgrimes l = mbp->msg_bufx - mbp->msg_bufr; 1541541Srgrimes if (l < 0) 15536179Sphk l = mbp->msg_size - mbp->msg_bufr; 1561541Srgrimes l = min(l, uio->uio_resid); 1571541Srgrimes if (l == 0) 1581541Srgrimes break; 15936179Sphk error = uiomove((caddr_t)msgbufp->msg_ptr + mbp->msg_bufr, 16036179Sphk (int)l, uio); 1611541Srgrimes if (error) 1621541Srgrimes break; 1631541Srgrimes mbp->msg_bufr += l; 16436179Sphk if (mbp->msg_bufr >= mbp->msg_size) 1651541Srgrimes mbp->msg_bufr = 0; 1661541Srgrimes } 1671541Srgrimes return (error); 1681541Srgrimes} 1691541Srgrimes 1701541Srgrimes/*ARGSUSED*/ 17112675Sjulianstatic int 17229357Speterlogpoll(dev, events, p) 1731541Srgrimes dev_t dev; 17429357Speter int events; 1751541Srgrimes struct proc *p; 1761541Srgrimes{ 17729357Speter int s; 17829357Speter int revents = 0; 1791541Srgrimes 18029357Speter s = splhigh(); 1811541Srgrimes 18246568Speter if (events & (POLLIN | POLLRDNORM)) { 18329357Speter if (msgbufp->msg_bufr != msgbufp->msg_bufx) 18429357Speter revents |= events & (POLLIN | POLLRDNORM); 18529357Speter else 18629357Speter selrecord(p, &logsoftc.sc_selp); 18746568Speter } 1881541Srgrimes splx(s); 18929357Speter return (revents); 1901541Srgrimes} 1911541Srgrimes 1921549Srgrimesvoid 1931541Srgrimeslogwakeup() 1941541Srgrimes{ 1951541Srgrimes if (!log_open) 1961541Srgrimes return; 1971541Srgrimes selwakeup(&logsoftc.sc_selp); 19841086Struckman if ((logsoftc.sc_state & LOG_ASYNC) && logsoftc.sc_sigio != NULL) 19941086Struckman pgsigio(logsoftc.sc_sigio, SIGIO, 0); 2001541Srgrimes if (logsoftc.sc_state & LOG_RDWAIT) { 2011541Srgrimes wakeup((caddr_t)msgbufp); 2021541Srgrimes logsoftc.sc_state &= ~LOG_RDWAIT; 2031541Srgrimes } 2041541Srgrimes} 2051541Srgrimes 2061541Srgrimes/*ARGSUSED*/ 20712675Sjulianstatic int 2081541Srgrimeslogioctl(dev, com, data, flag, p) 2091541Srgrimes dev_t dev; 21036735Sdfr u_long com; 2111541Srgrimes caddr_t data; 2121541Srgrimes int flag; 2131541Srgrimes struct proc *p; 2141541Srgrimes{ 2151541Srgrimes long l; 2161541Srgrimes int s; 2171541Srgrimes 2181541Srgrimes switch (com) { 2191541Srgrimes 2201541Srgrimes /* return number of characters immediately available */ 2211541Srgrimes case FIONREAD: 2221541Srgrimes s = splhigh(); 2231541Srgrimes l = msgbufp->msg_bufx - msgbufp->msg_bufr; 2241541Srgrimes splx(s); 2251541Srgrimes if (l < 0) 22636179Sphk l += msgbufp->msg_size; 2271541Srgrimes *(int *)data = l; 2281541Srgrimes break; 2291541Srgrimes 2301541Srgrimes case FIONBIO: 2311541Srgrimes break; 2321541Srgrimes 2331541Srgrimes case FIOASYNC: 2341541Srgrimes if (*(int *)data) 2351541Srgrimes logsoftc.sc_state |= LOG_ASYNC; 2361541Srgrimes else 2371541Srgrimes logsoftc.sc_state &= ~LOG_ASYNC; 2381541Srgrimes break; 2391541Srgrimes 24041086Struckman case FIOSETOWN: 24141086Struckman return (fsetown(*(int *)data, &logsoftc.sc_sigio)); 24241086Struckman 24341086Struckman case FIOGETOWN: 24441086Struckman *(int *)data = fgetown(logsoftc.sc_sigio); 2451541Srgrimes break; 2461541Srgrimes 24741086Struckman /* This is deprecated, FIOSETOWN should be used instead. */ 24841086Struckman case TIOCSPGRP: 24941086Struckman return (fsetown(-(*(int *)data), &logsoftc.sc_sigio)); 25041086Struckman 25141086Struckman /* This is deprecated, FIOGETOWN should be used instead */ 2521541Srgrimes case TIOCGPGRP: 25341086Struckman *(int *)data = -fgetown(logsoftc.sc_sigio); 2541541Srgrimes break; 2551541Srgrimes 2561541Srgrimes default: 2578161Sjkh return (ENOTTY); 2581541Srgrimes } 2591541Srgrimes return (0); 2601541Srgrimes} 26112517Sjulian 26212517Sjulian 26329506Sbdestatic void log_drvinit __P((void *unused)); 26450254Sphk 26512675Sjulianstatic void 26629506Sbdelog_drvinit(unused) 26729506Sbde void *unused; 26812517Sjulian{ 26950254Sphk make_dev(&log_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "klog"); 27012517Sjulian} 27112517Sjulian 27212517SjulianSYSINIT(logdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,log_drvinit,NULL) 273