subr_log.c revision 1549
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 341541Srgrimes */ 351541Srgrimes 361541Srgrimes/* 371541Srgrimes * Error log buffer for kernel printf's. 381541Srgrimes */ 391541Srgrimes 401541Srgrimes#include <sys/param.h> 411541Srgrimes#include <sys/systm.h> 421541Srgrimes#include <sys/proc.h> 431541Srgrimes#include <sys/vnode.h> 441541Srgrimes#include <sys/ioctl.h> 451541Srgrimes#include <sys/msgbuf.h> 461541Srgrimes#include <sys/file.h> 471541Srgrimes 481541Srgrimes#define LOG_RDPRI (PZERO + 1) 491541Srgrimes 501541Srgrimes#define LOG_ASYNC 0x04 511541Srgrimes#define LOG_RDWAIT 0x08 521541Srgrimes 531541Srgrimesstruct logsoftc { 541541Srgrimes int sc_state; /* see above for possibilities */ 551541Srgrimes struct selinfo sc_selp; /* process waiting on select call */ 561541Srgrimes int sc_pgid; /* process/group for async I/O */ 571541Srgrimes} logsoftc; 581541Srgrimes 591541Srgrimesint log_open; /* also used in log() */ 601541Srgrimes 611541Srgrimes/*ARGSUSED*/ 621549Srgrimesint 631541Srgrimeslogopen(dev, flags, mode, p) 641541Srgrimes dev_t dev; 651541Srgrimes int flags, mode; 661541Srgrimes struct proc *p; 671541Srgrimes{ 681541Srgrimes register struct msgbuf *mbp = msgbufp; 691541Srgrimes 701541Srgrimes if (log_open) 711541Srgrimes return (EBUSY); 721541Srgrimes log_open = 1; 731541Srgrimes logsoftc.sc_pgid = p->p_pid; /* signal process only */ 741541Srgrimes /* 751541Srgrimes * Potential race here with putchar() but since putchar should be 761541Srgrimes * called by autoconf, msg_magic should be initialized by the time 771541Srgrimes * we get here. 781541Srgrimes */ 791541Srgrimes if (mbp->msg_magic != MSG_MAGIC) { 801541Srgrimes register int i; 811541Srgrimes 821541Srgrimes mbp->msg_magic = MSG_MAGIC; 831541Srgrimes mbp->msg_bufx = mbp->msg_bufr = 0; 841541Srgrimes for (i=0; i < MSG_BSIZE; i++) 851541Srgrimes mbp->msg_bufc[i] = 0; 861541Srgrimes } 871541Srgrimes return (0); 881541Srgrimes} 891541Srgrimes 901541Srgrimes/*ARGSUSED*/ 911549Srgrimesint 921541Srgrimeslogclose(dev, flag, mode, p) 931541Srgrimes dev_t dev; 941541Srgrimes int flag, mode; 951541Srgrimes struct proc *p; 961541Srgrimes{ 971541Srgrimes 981541Srgrimes log_open = 0; 991541Srgrimes logsoftc.sc_state = 0; 1001541Srgrimes return (0); 1011541Srgrimes} 1021541Srgrimes 1031541Srgrimes/*ARGSUSED*/ 1041549Srgrimesint 1051541Srgrimeslogread(dev, uio, flag) 1061541Srgrimes dev_t dev; 1071541Srgrimes struct uio *uio; 1081541Srgrimes int flag; 1091541Srgrimes{ 1101541Srgrimes register struct msgbuf *mbp = msgbufp; 1111541Srgrimes register long l; 1121541Srgrimes register int s; 1131541Srgrimes int error = 0; 1141541Srgrimes 1151541Srgrimes s = splhigh(); 1161541Srgrimes while (mbp->msg_bufr == mbp->msg_bufx) { 1171541Srgrimes if (flag & IO_NDELAY) { 1181541Srgrimes splx(s); 1191541Srgrimes return (EWOULDBLOCK); 1201541Srgrimes } 1211541Srgrimes logsoftc.sc_state |= LOG_RDWAIT; 1221541Srgrimes if (error = tsleep((caddr_t)mbp, LOG_RDPRI | PCATCH, 1231541Srgrimes "klog", 0)) { 1241541Srgrimes splx(s); 1251541Srgrimes return (error); 1261541Srgrimes } 1271541Srgrimes } 1281541Srgrimes splx(s); 1291541Srgrimes logsoftc.sc_state &= ~LOG_RDWAIT; 1301541Srgrimes 1311541Srgrimes while (uio->uio_resid > 0) { 1321541Srgrimes l = mbp->msg_bufx - mbp->msg_bufr; 1331541Srgrimes if (l < 0) 1341541Srgrimes l = MSG_BSIZE - mbp->msg_bufr; 1351541Srgrimes l = min(l, uio->uio_resid); 1361541Srgrimes if (l == 0) 1371541Srgrimes break; 1381541Srgrimes error = uiomove((caddr_t)&mbp->msg_bufc[mbp->msg_bufr], 1391541Srgrimes (int)l, uio); 1401541Srgrimes if (error) 1411541Srgrimes break; 1421541Srgrimes mbp->msg_bufr += l; 1431541Srgrimes if (mbp->msg_bufr < 0 || mbp->msg_bufr >= MSG_BSIZE) 1441541Srgrimes mbp->msg_bufr = 0; 1451541Srgrimes } 1461541Srgrimes return (error); 1471541Srgrimes} 1481541Srgrimes 1491541Srgrimes/*ARGSUSED*/ 1501549Srgrimesint 1511541Srgrimeslogselect(dev, rw, p) 1521541Srgrimes dev_t dev; 1531541Srgrimes int rw; 1541541Srgrimes struct proc *p; 1551541Srgrimes{ 1561541Srgrimes int s = splhigh(); 1571541Srgrimes 1581541Srgrimes switch (rw) { 1591541Srgrimes 1601541Srgrimes case FREAD: 1611541Srgrimes if (msgbufp->msg_bufr != msgbufp->msg_bufx) { 1621541Srgrimes splx(s); 1631541Srgrimes return (1); 1641541Srgrimes } 1651541Srgrimes selrecord(p, &logsoftc.sc_selp); 1661541Srgrimes break; 1671541Srgrimes } 1681541Srgrimes splx(s); 1691541Srgrimes return (0); 1701541Srgrimes} 1711541Srgrimes 1721549Srgrimesvoid 1731541Srgrimeslogwakeup() 1741541Srgrimes{ 1751541Srgrimes struct proc *p; 1761541Srgrimes 1771541Srgrimes if (!log_open) 1781541Srgrimes return; 1791541Srgrimes selwakeup(&logsoftc.sc_selp); 1801541Srgrimes if (logsoftc.sc_state & LOG_ASYNC) { 1811541Srgrimes if (logsoftc.sc_pgid < 0) 1821541Srgrimes gsignal(-logsoftc.sc_pgid, SIGIO); 1831541Srgrimes else if (p = pfind(logsoftc.sc_pgid)) 1841541Srgrimes psignal(p, SIGIO); 1851541Srgrimes } 1861541Srgrimes if (logsoftc.sc_state & LOG_RDWAIT) { 1871541Srgrimes wakeup((caddr_t)msgbufp); 1881541Srgrimes logsoftc.sc_state &= ~LOG_RDWAIT; 1891541Srgrimes } 1901541Srgrimes} 1911541Srgrimes 1921541Srgrimes/*ARGSUSED*/ 1931549Srgrimesint 1941541Srgrimeslogioctl(dev, com, data, flag, p) 1951541Srgrimes dev_t dev; 1961541Srgrimes int com; 1971541Srgrimes caddr_t data; 1981541Srgrimes int flag; 1991541Srgrimes struct proc *p; 2001541Srgrimes{ 2011541Srgrimes long l; 2021541Srgrimes int s; 2031541Srgrimes 2041541Srgrimes switch (com) { 2051541Srgrimes 2061541Srgrimes /* return number of characters immediately available */ 2071541Srgrimes case FIONREAD: 2081541Srgrimes s = splhigh(); 2091541Srgrimes l = msgbufp->msg_bufx - msgbufp->msg_bufr; 2101541Srgrimes splx(s); 2111541Srgrimes if (l < 0) 2121541Srgrimes l += MSG_BSIZE; 2131541Srgrimes *(int *)data = l; 2141541Srgrimes break; 2151541Srgrimes 2161541Srgrimes case FIONBIO: 2171541Srgrimes break; 2181541Srgrimes 2191541Srgrimes case FIOASYNC: 2201541Srgrimes if (*(int *)data) 2211541Srgrimes logsoftc.sc_state |= LOG_ASYNC; 2221541Srgrimes else 2231541Srgrimes logsoftc.sc_state &= ~LOG_ASYNC; 2241541Srgrimes break; 2251541Srgrimes 2261541Srgrimes case TIOCSPGRP: 2271541Srgrimes logsoftc.sc_pgid = *(int *)data; 2281541Srgrimes break; 2291541Srgrimes 2301541Srgrimes case TIOCGPGRP: 2311541Srgrimes *(int *)data = logsoftc.sc_pgid; 2321541Srgrimes break; 2331541Srgrimes 2341541Srgrimes default: 2351541Srgrimes return (-1); 2361541Srgrimes } 2371541Srgrimes return (0); 2381541Srgrimes} 239