/* * Copyright (c) 1982, 1986, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)subr_log.c 8.1 (Berkeley) 6/10/93 * $FreeBSD$ */ /* * Error log buffer for kernel printf's. */ #include <sys/param.h> #include <sys/systm.h> #include <sys/conf.h> #include <sys/proc.h> #include <sys/vnode.h> #include <sys/filio.h> #include <sys/ttycom.h> #include <sys/msgbuf.h> #include <sys/signalvar.h> #include <sys/kernel.h> #include <sys/poll.h> #include <sys/filedesc.h> #include <sys/sysctl.h> #define LOG_RDPRI (PZERO + 1) #define LOG_ASYNC 0x04 #define LOG_RDWAIT 0x08 static d_open_t logopen; static d_close_t logclose; static d_read_t logread; static d_ioctl_t logioctl; static d_poll_t logpoll; static void logtimeout(void *arg); #define CDEV_MAJOR 7 static struct cdevsw log_cdevsw = { /* open */ logopen, /* close */ logclose, /* read */ logread, /* write */ nowrite, /* ioctl */ logioctl, /* poll */ logpoll, /* mmap */ nommap, /* strategy */ nostrategy, /* name */ "log", /* maj */ CDEV_MAJOR, /* dump */ nodump, /* psize */ nopsize, /* flags */ 0, }; static struct logsoftc { int sc_state; /* see above for possibilities */ struct selinfo sc_selp; /* process waiting on select call */ struct sigio *sc_sigio; /* information for async I/O */ struct callout sc_callout; /* callout to wakeup syslog */ } logsoftc; int log_open; /* also used in log() */ /* Times per second to check for a pending syslog wakeup. */ static int log_wakeups_per_second = 5; SYSCTL_INT(_kern, OID_AUTO, log_wakeups_per_second, CTLFLAG_RW, &log_wakeups_per_second, 0, ""); /*ARGSUSED*/ static int logopen(dev_t dev, int flags, int mode, struct thread *td) { if (log_open) return (EBUSY); log_open = 1; callout_init(&logsoftc.sc_callout, 0); fsetown(td->td_proc->p_pid, &logsoftc.sc_sigio); /* signal process only */ callout_reset(&logsoftc.sc_callout, hz / log_wakeups_per_second, logtimeout, NULL); return (0); } /*ARGSUSED*/ static int logclose(dev_t dev, int flag, int mode, struct thread *td) { log_open = 0; callout_stop(&logsoftc.sc_callout); logsoftc.sc_state = 0; funsetown(&logsoftc.sc_sigio); return (0); } /*ARGSUSED*/ static int logread(dev_t dev, struct uio *uio, int flag) { struct msgbuf *mbp = msgbufp; int error = 0, l, s; s = splhigh(); while (mbp->msg_bufr == mbp->msg_bufx) { if (flag & IO_NDELAY) { splx(s); return (EWOULDBLOCK); } logsoftc.sc_state |= LOG_RDWAIT; if ((error = tsleep(mbp, LOG_RDPRI | PCATCH, "klog", 0))) { splx(s); return (error); } } splx(s); logsoftc.sc_state &= ~LOG_RDWAIT; while (uio->uio_resid > 0) { l = mbp->msg_bufx - mbp->msg_bufr; if (l < 0) l = mbp->msg_size - mbp->msg_bufr; l = imin(l, uio->uio_resid); if (l == 0) break; error = uiomove((caddr_t)msgbufp->msg_ptr + mbp->msg_bufr, l, uio); if (error) break; mbp->msg_bufr += l; if (mbp->msg_bufr >= mbp->msg_size) mbp->msg_bufr = 0; } return (error); } /*ARGSUSED*/ static int logpoll(dev_t dev, int events, struct thread *td) { int s; int revents = 0; s = splhigh(); if (events & (POLLIN | POLLRDNORM)) { if (msgbufp->msg_bufr != msgbufp->msg_bufx) revents |= events & (POLLIN | POLLRDNORM); else selrecord(td, &logsoftc.sc_selp); } splx(s); return (revents); } static void logtimeout(void *arg) { if (!log_open) return; if (msgbuftrigger == 0) { callout_reset(&logsoftc.sc_callout, hz / log_wakeups_per_second, logtimeout, NULL); return; } msgbuftrigger = 0; selwakeup(&logsoftc.sc_selp); if ((logsoftc.sc_state & LOG_ASYNC) && logsoftc.sc_sigio != NULL) pgsigio(&logsoftc.sc_sigio, SIGIO, 0); if (logsoftc.sc_state & LOG_RDWAIT) { wakeup((caddr_t)msgbufp); logsoftc.sc_state &= ~LOG_RDWAIT; } callout_reset(&logsoftc.sc_callout, hz / log_wakeups_per_second, logtimeout, NULL); } /*ARGSUSED*/ static int logioctl(dev_t dev, u_long com, caddr_t data, int flag, struct thread *td) { int l, s; switch (com) { /* return number of characters immediately available */ case FIONREAD: s = splhigh(); l = msgbufp->msg_bufx - msgbufp->msg_bufr; splx(s); if (l < 0) l += msgbufp->msg_size; *(int *)data = l; break; case FIONBIO: break; case FIOASYNC: if (*(int *)data) logsoftc.sc_state |= LOG_ASYNC; else logsoftc.sc_state &= ~LOG_ASYNC; break; case FIOSETOWN: return (fsetown(*(int *)data, &logsoftc.sc_sigio)); case FIOGETOWN: *(int *)data = fgetown(&logsoftc.sc_sigio); break; /* This is deprecated, FIOSETOWN should be used instead. */ case TIOCSPGRP: return (fsetown(-(*(int *)data), &logsoftc.sc_sigio)); /* This is deprecated, FIOGETOWN should be used instead */ case TIOCGPGRP: *(int *)data = -fgetown(&logsoftc.sc_sigio); break; default: return (ENOTTY); } return (0); } static void log_drvinit(void *unused) { make_dev(&log_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "klog"); } SYSINIT(logdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,log_drvinit,NULL)