subr_log.c revision 8161
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 348161Sjkh * $Id: subr_log.c,v 1.6 1995/04/29 05:09:19 jkh Exp $ 351541Srgrimes */ 361541Srgrimes 371541Srgrimes/* 381541Srgrimes * Error log buffer for kernel printf's. 391541Srgrimes */ 401541Srgrimes 411541Srgrimes#include <sys/param.h> 421541Srgrimes#include <sys/systm.h> 431541Srgrimes#include <sys/proc.h> 441541Srgrimes#include <sys/vnode.h> 451541Srgrimes#include <sys/ioctl.h> 461541Srgrimes#include <sys/msgbuf.h> 471541Srgrimes#include <sys/file.h> 483308Sphk#include <sys/signalvar.h> 491541Srgrimes 501541Srgrimes#define LOG_RDPRI (PZERO + 1) 511541Srgrimes 521541Srgrimes#define LOG_ASYNC 0x04 531541Srgrimes#define LOG_RDWAIT 0x08 541541Srgrimes 551541Srgrimesstruct logsoftc { 561541Srgrimes int sc_state; /* see above for possibilities */ 571541Srgrimes struct selinfo sc_selp; /* process waiting on select call */ 581541Srgrimes int sc_pgid; /* process/group for async I/O */ 591541Srgrimes} logsoftc; 601541Srgrimes 611541Srgrimesint log_open; /* also used in log() */ 621541Srgrimes 631541Srgrimes/*ARGSUSED*/ 641549Srgrimesint 651541Srgrimeslogopen(dev, flags, mode, p) 661541Srgrimes dev_t dev; 671541Srgrimes int flags, mode; 681541Srgrimes struct proc *p; 691541Srgrimes{ 701541Srgrimes register struct msgbuf *mbp = msgbufp; 711541Srgrimes 721541Srgrimes if (log_open) 731541Srgrimes return (EBUSY); 741541Srgrimes log_open = 1; 751541Srgrimes logsoftc.sc_pgid = p->p_pid; /* signal process only */ 761541Srgrimes /* 771541Srgrimes * Potential race here with putchar() but since putchar should be 781541Srgrimes * called by autoconf, msg_magic should be initialized by the time 791541Srgrimes * we get here. 801541Srgrimes */ 811541Srgrimes if (mbp->msg_magic != MSG_MAGIC) { 821541Srgrimes register int i; 831541Srgrimes 841541Srgrimes mbp->msg_magic = MSG_MAGIC; 851541Srgrimes mbp->msg_bufx = mbp->msg_bufr = 0; 861541Srgrimes for (i=0; i < MSG_BSIZE; i++) 871541Srgrimes mbp->msg_bufc[i] = 0; 881541Srgrimes } 891541Srgrimes return (0); 901541Srgrimes} 911541Srgrimes 921541Srgrimes/*ARGSUSED*/ 931549Srgrimesint 941541Srgrimeslogclose(dev, flag, mode, p) 951541Srgrimes dev_t dev; 961541Srgrimes int flag, mode; 971541Srgrimes struct proc *p; 981541Srgrimes{ 991541Srgrimes 1001541Srgrimes log_open = 0; 1011541Srgrimes logsoftc.sc_state = 0; 1021541Srgrimes return (0); 1031541Srgrimes} 1041541Srgrimes 1051541Srgrimes/*ARGSUSED*/ 1061549Srgrimesint 1071541Srgrimeslogread(dev, uio, flag) 1081541Srgrimes dev_t dev; 1091541Srgrimes struct uio *uio; 1101541Srgrimes int flag; 1111541Srgrimes{ 1121541Srgrimes register struct msgbuf *mbp = msgbufp; 1131541Srgrimes register long l; 1141541Srgrimes register int s; 1151541Srgrimes int error = 0; 1161541Srgrimes 1171541Srgrimes s = splhigh(); 1181541Srgrimes while (mbp->msg_bufr == mbp->msg_bufx) { 1191541Srgrimes if (flag & IO_NDELAY) { 1201541Srgrimes splx(s); 1211541Srgrimes return (EWOULDBLOCK); 1221541Srgrimes } 1231541Srgrimes logsoftc.sc_state |= LOG_RDWAIT; 1243098Sphk if ((error = tsleep((caddr_t)mbp, LOG_RDPRI | PCATCH, 1253098Sphk "klog", 0))) { 1261541Srgrimes splx(s); 1271541Srgrimes return (error); 1281541Srgrimes } 1291541Srgrimes } 1301541Srgrimes splx(s); 1311541Srgrimes logsoftc.sc_state &= ~LOG_RDWAIT; 1321541Srgrimes 1331541Srgrimes while (uio->uio_resid > 0) { 1341541Srgrimes l = mbp->msg_bufx - mbp->msg_bufr; 1351541Srgrimes if (l < 0) 1361541Srgrimes l = MSG_BSIZE - mbp->msg_bufr; 1371541Srgrimes l = min(l, uio->uio_resid); 1381541Srgrimes if (l == 0) 1391541Srgrimes break; 1401541Srgrimes error = uiomove((caddr_t)&mbp->msg_bufc[mbp->msg_bufr], 1411541Srgrimes (int)l, uio); 1421541Srgrimes if (error) 1431541Srgrimes break; 1441541Srgrimes mbp->msg_bufr += l; 1451541Srgrimes if (mbp->msg_bufr < 0 || mbp->msg_bufr >= MSG_BSIZE) 1461541Srgrimes mbp->msg_bufr = 0; 1471541Srgrimes } 1481541Srgrimes return (error); 1491541Srgrimes} 1501541Srgrimes 1511541Srgrimes/*ARGSUSED*/ 1521549Srgrimesint 1531541Srgrimeslogselect(dev, rw, p) 1541541Srgrimes dev_t dev; 1551541Srgrimes int rw; 1561541Srgrimes struct proc *p; 1571541Srgrimes{ 1581541Srgrimes int s = splhigh(); 1591541Srgrimes 1601541Srgrimes switch (rw) { 1611541Srgrimes 1621541Srgrimes case FREAD: 1631541Srgrimes if (msgbufp->msg_bufr != msgbufp->msg_bufx) { 1641541Srgrimes splx(s); 1651541Srgrimes return (1); 1661541Srgrimes } 1671541Srgrimes selrecord(p, &logsoftc.sc_selp); 1681541Srgrimes break; 1691541Srgrimes } 1701541Srgrimes splx(s); 1711541Srgrimes return (0); 1721541Srgrimes} 1731541Srgrimes 1741549Srgrimesvoid 1751541Srgrimeslogwakeup() 1761541Srgrimes{ 1771541Srgrimes struct proc *p; 1781541Srgrimes 1791541Srgrimes if (!log_open) 1801541Srgrimes return; 1811541Srgrimes selwakeup(&logsoftc.sc_selp); 1821541Srgrimes if (logsoftc.sc_state & LOG_ASYNC) { 1831541Srgrimes if (logsoftc.sc_pgid < 0) 1841541Srgrimes gsignal(-logsoftc.sc_pgid, SIGIO); 1853098Sphk else if ((p = pfind(logsoftc.sc_pgid))) 1861541Srgrimes psignal(p, SIGIO); 1871541Srgrimes } 1881541Srgrimes if (logsoftc.sc_state & LOG_RDWAIT) { 1891541Srgrimes wakeup((caddr_t)msgbufp); 1901541Srgrimes logsoftc.sc_state &= ~LOG_RDWAIT; 1911541Srgrimes } 1921541Srgrimes} 1931541Srgrimes 1941541Srgrimes/*ARGSUSED*/ 1951549Srgrimesint 1961541Srgrimeslogioctl(dev, com, data, flag, p) 1971541Srgrimes dev_t dev; 1981541Srgrimes int com; 1991541Srgrimes caddr_t data; 2001541Srgrimes int flag; 2011541Srgrimes struct proc *p; 2021541Srgrimes{ 2031541Srgrimes long l; 2041541Srgrimes int s; 2051541Srgrimes 2061541Srgrimes switch (com) { 2071541Srgrimes 2081541Srgrimes /* return number of characters immediately available */ 2091541Srgrimes case FIONREAD: 2101541Srgrimes s = splhigh(); 2111541Srgrimes l = msgbufp->msg_bufx - msgbufp->msg_bufr; 2121541Srgrimes splx(s); 2131541Srgrimes if (l < 0) 2141541Srgrimes l += MSG_BSIZE; 2151541Srgrimes *(int *)data = l; 2161541Srgrimes break; 2171541Srgrimes 2181541Srgrimes case FIONBIO: 2191541Srgrimes break; 2201541Srgrimes 2211541Srgrimes case FIOASYNC: 2221541Srgrimes if (*(int *)data) 2231541Srgrimes logsoftc.sc_state |= LOG_ASYNC; 2241541Srgrimes else 2251541Srgrimes logsoftc.sc_state &= ~LOG_ASYNC; 2261541Srgrimes break; 2271541Srgrimes 2281541Srgrimes case TIOCSPGRP: 2291541Srgrimes logsoftc.sc_pgid = *(int *)data; 2301541Srgrimes break; 2311541Srgrimes 2321541Srgrimes case TIOCGPGRP: 2331541Srgrimes *(int *)data = logsoftc.sc_pgid; 2341541Srgrimes break; 2351541Srgrimes 2361541Srgrimes default: 2378161Sjkh return (ENOTTY); 2381541Srgrimes } 2391541Srgrimes return (0); 2401541Srgrimes} 241