subr_log.c (237fdd787b20699fc2c01387011b06a9ce746cfa) subr_log.c (ca1d2f657ac8942f180f7d1ab328400ae8524bf0)
1/*-
2 * Copyright (c) 1982, 1986, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright

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48#include <sys/kernel.h>
49#include <sys/poll.h>
50#include <sys/filedesc.h>
51#include <sys/sysctl.h>
52
53#define LOG_RDPRI (PZERO + 1)
54
55#define LOG_ASYNC 0x04
1/*-
2 * Copyright (c) 1982, 1986, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright

--- 39 unchanged lines hidden (view full) ---

48#include <sys/kernel.h>
49#include <sys/poll.h>
50#include <sys/filedesc.h>
51#include <sys/sysctl.h>
52
53#define LOG_RDPRI (PZERO + 1)
54
55#define LOG_ASYNC 0x04
56#define LOG_RDWAIT 0x08
57
58static d_open_t logopen;
59static d_close_t logclose;
60static d_read_t logread;
61static d_ioctl_t logioctl;
62static d_poll_t logpoll;
63
64static void logtimeout(void *arg);
65
66static struct cdevsw log_cdevsw = {
67 .d_version = D_VERSION,
56
57static d_open_t logopen;
58static d_close_t logclose;
59static d_read_t logread;
60static d_ioctl_t logioctl;
61static d_poll_t logpoll;
62
63static void logtimeout(void *arg);
64
65static struct cdevsw log_cdevsw = {
66 .d_version = D_VERSION,
68 .d_flags = D_NEEDGIANT,
69 .d_open = logopen,
70 .d_close = logclose,
71 .d_read = logread,
72 .d_ioctl = logioctl,
73 .d_poll = logpoll,
74 .d_name = "log",
75};
76
77static struct logsoftc {
78 int sc_state; /* see above for possibilities */
79 struct selinfo sc_selp; /* process waiting on select call */
80 struct sigio *sc_sigio; /* information for async I/O */
81 struct callout sc_callout; /* callout to wakeup syslog */
82} logsoftc;
83
67 .d_open = logopen,
68 .d_close = logclose,
69 .d_read = logread,
70 .d_ioctl = logioctl,
71 .d_poll = logpoll,
72 .d_name = "log",
73};
74
75static struct logsoftc {
76 int sc_state; /* see above for possibilities */
77 struct selinfo sc_selp; /* process waiting on select call */
78 struct sigio *sc_sigio; /* information for async I/O */
79 struct callout sc_callout; /* callout to wakeup syslog */
80} logsoftc;
81
84int log_open; /* also used in log() */
82int log_open; /* also used in log() */
83static struct cv log_wakeup;
84struct mtx msgbuf_lock;
85MTX_SYSINIT(msgbuf_lock, &msgbuf_lock, "msgbuf lock", MTX_DEF);
85
86/* Times per second to check for a pending syslog wakeup. */
87static int log_wakeups_per_second = 5;
88SYSCTL_INT(_kern, OID_AUTO, log_wakeups_per_second, CTLFLAG_RW,
89 &log_wakeups_per_second, 0, "");
90
91/*ARGSUSED*/
92static int
93logopen(struct cdev *dev, int flags, int mode, struct thread *td)
94{
86
87/* Times per second to check for a pending syslog wakeup. */
88static int log_wakeups_per_second = 5;
89SYSCTL_INT(_kern, OID_AUTO, log_wakeups_per_second, CTLFLAG_RW,
90 &log_wakeups_per_second, 0, "");
91
92/*ARGSUSED*/
93static int
94logopen(struct cdev *dev, int flags, int mode, struct thread *td)
95{
95 if (log_open)
96 return (EBUSY);
97 log_open = 1;
98 callout_init(&logsoftc.sc_callout, 0);
99 fsetown(td->td_proc->p_pid, &logsoftc.sc_sigio); /* signal process only */
96
100 if (log_wakeups_per_second < 1) {
101 printf("syslog wakeup is less than one. Adjusting to 1.\n");
102 log_wakeups_per_second = 1;
103 }
97 if (log_wakeups_per_second < 1) {
98 printf("syslog wakeup is less than one. Adjusting to 1.\n");
99 log_wakeups_per_second = 1;
100 }
101
102 mtx_lock(&msgbuf_lock);
103 if (log_open) {
104 mtx_unlock(&msgbuf_lock);
105 return (EBUSY);
106 }
107 log_open = 1;
104 callout_reset(&logsoftc.sc_callout, hz / log_wakeups_per_second,
105 logtimeout, NULL);
108 callout_reset(&logsoftc.sc_callout, hz / log_wakeups_per_second,
109 logtimeout, NULL);
110 mtx_unlock(&msgbuf_lock);
111
112 fsetown(td->td_proc->p_pid, &logsoftc.sc_sigio); /* signal process only */
106 return (0);
107}
108
109/*ARGSUSED*/
110static int
111logclose(struct cdev *dev, int flag, int mode, struct thread *td)
112{
113
113 return (0);
114}
115
116/*ARGSUSED*/
117static int
118logclose(struct cdev *dev, int flag, int mode, struct thread *td)
119{
120
114 log_open = 0;
121 funsetown(&logsoftc.sc_sigio);
122
123 mtx_lock(&msgbuf_lock);
115 callout_stop(&logsoftc.sc_callout);
116 logsoftc.sc_state = 0;
124 callout_stop(&logsoftc.sc_callout);
125 logsoftc.sc_state = 0;
117 funsetown(&logsoftc.sc_sigio);
126 log_open = 0;
127 mtx_unlock(&msgbuf_lock);
128
118 return (0);
119}
120
121/*ARGSUSED*/
122static int
123logread(struct cdev *dev, struct uio *uio, int flag)
124{
125 char buf[128];
126 struct msgbuf *mbp = msgbufp;
129 return (0);
130}
131
132/*ARGSUSED*/
133static int
134logread(struct cdev *dev, struct uio *uio, int flag)
135{
136 char buf[128];
137 struct msgbuf *mbp = msgbufp;
127 int error = 0, l, s;
138 int error = 0, l;
128
139
129 s = splhigh();
140 mtx_lock(&msgbuf_lock);
130 while (msgbuf_getcount(mbp) == 0) {
131 if (flag & IO_NDELAY) {
141 while (msgbuf_getcount(mbp) == 0) {
142 if (flag & IO_NDELAY) {
132 splx(s);
143 mtx_unlock(&msgbuf_lock);
133 return (EWOULDBLOCK);
134 }
144 return (EWOULDBLOCK);
145 }
135 logsoftc.sc_state |= LOG_RDWAIT;
136 if ((error = tsleep(mbp, LOG_RDPRI | PCATCH, "klog", 0))) {
137 splx(s);
146 if ((error = cv_wait_sig(&log_wakeup, &msgbuf_lock)) != 0) {
147 mtx_unlock(&msgbuf_lock);
138 return (error);
139 }
140 }
148 return (error);
149 }
150 }
141 splx(s);
142 logsoftc.sc_state &= ~LOG_RDWAIT;
143
144 while (uio->uio_resid > 0) {
145 l = imin(sizeof(buf), uio->uio_resid);
146 l = msgbuf_getbytes(mbp, buf, l);
147 if (l == 0)
148 break;
151
152 while (uio->uio_resid > 0) {
153 l = imin(sizeof(buf), uio->uio_resid);
154 l = msgbuf_getbytes(mbp, buf, l);
155 if (l == 0)
156 break;
157 mtx_unlock(&msgbuf_lock);
149 error = uiomove(buf, l, uio);
158 error = uiomove(buf, l, uio);
150 if (error)
151 break;
159 if (error || uio->uio_resid == 0)
160 return (error);
161 mtx_lock(&msgbuf_lock);
152 }
162 }
163 mtx_unlock(&msgbuf_lock);
153 return (error);
154}
155
156/*ARGSUSED*/
157static int
158logpoll(struct cdev *dev, int events, struct thread *td)
159{
164 return (error);
165}
166
167/*ARGSUSED*/
168static int
169logpoll(struct cdev *dev, int events, struct thread *td)
170{
160 int s;
161 int revents = 0;
162
171 int revents = 0;
172
163 s = splhigh();
164
165 if (events & (POLLIN | POLLRDNORM)) {
173 if (events & (POLLIN | POLLRDNORM)) {
174 mtx_lock(&msgbuf_lock);
166 if (msgbuf_getcount(msgbufp) > 0)
167 revents |= events & (POLLIN | POLLRDNORM);
168 else
169 selrecord(td, &logsoftc.sc_selp);
175 if (msgbuf_getcount(msgbufp) > 0)
176 revents |= events & (POLLIN | POLLRDNORM);
177 else
178 selrecord(td, &logsoftc.sc_selp);
179 mtx_unlock(&msgbuf_lock);
170 }
180 }
171 splx(s);
172 return (revents);
173}
174
175static void
176logtimeout(void *arg)
177{
178
179 if (!log_open)
180 return;
181 if (log_wakeups_per_second < 1) {
182 printf("syslog wakeup is less than one. Adjusting to 1.\n");
183 log_wakeups_per_second = 1;
184 }
185 if (msgbuftrigger == 0) {
181 return (revents);
182}
183
184static void
185logtimeout(void *arg)
186{
187
188 if (!log_open)
189 return;
190 if (log_wakeups_per_second < 1) {
191 printf("syslog wakeup is less than one. Adjusting to 1.\n");
192 log_wakeups_per_second = 1;
193 }
194 if (msgbuftrigger == 0) {
186 callout_reset(&logsoftc.sc_callout,
187 hz / log_wakeups_per_second, logtimeout, NULL);
195 callout_schedule(&logsoftc.sc_callout,
196 hz / log_wakeups_per_second);
188 return;
189 }
190 msgbuftrigger = 0;
191 selwakeuppri(&logsoftc.sc_selp, LOG_RDPRI);
192 if ((logsoftc.sc_state & LOG_ASYNC) && logsoftc.sc_sigio != NULL)
193 pgsigio(&logsoftc.sc_sigio, SIGIO, 0);
197 return;
198 }
199 msgbuftrigger = 0;
200 selwakeuppri(&logsoftc.sc_selp, LOG_RDPRI);
201 if ((logsoftc.sc_state & LOG_ASYNC) && logsoftc.sc_sigio != NULL)
202 pgsigio(&logsoftc.sc_sigio, SIGIO, 0);
194 if (logsoftc.sc_state & LOG_RDWAIT) {
195 wakeup(msgbufp);
196 logsoftc.sc_state &= ~LOG_RDWAIT;
197 }
198 callout_reset(&logsoftc.sc_callout, hz / log_wakeups_per_second,
199 logtimeout, NULL);
203 cv_broadcastpri(&log_wakeup, LOG_RDPRI);
204 callout_schedule(&logsoftc.sc_callout, hz / log_wakeups_per_second);
200}
201
202/*ARGSUSED*/
203static int
204logioctl(struct cdev *dev, u_long com, caddr_t data, int flag, struct thread *td)
205{
206
207 switch (com) {
208
209 /* return number of characters immediately available */
210 case FIONREAD:
211 *(int *)data = msgbuf_getcount(msgbufp);
212 break;
213
214 case FIONBIO:
215 break;
216
217 case FIOASYNC:
205}
206
207/*ARGSUSED*/
208static int
209logioctl(struct cdev *dev, u_long com, caddr_t data, int flag, struct thread *td)
210{
211
212 switch (com) {
213
214 /* return number of characters immediately available */
215 case FIONREAD:
216 *(int *)data = msgbuf_getcount(msgbufp);
217 break;
218
219 case FIONBIO:
220 break;
221
222 case FIOASYNC:
223 mtx_lock(&msgbuf_lock);
218 if (*(int *)data)
219 logsoftc.sc_state |= LOG_ASYNC;
220 else
221 logsoftc.sc_state &= ~LOG_ASYNC;
224 if (*(int *)data)
225 logsoftc.sc_state |= LOG_ASYNC;
226 else
227 logsoftc.sc_state &= ~LOG_ASYNC;
228 mtx_unlock(&msgbuf_lock);
222 break;
223
224 case FIOSETOWN:
225 return (fsetown(*(int *)data, &logsoftc.sc_sigio));
226
227 case FIOGETOWN:
228 *(int *)data = fgetown(&logsoftc.sc_sigio);
229 break;

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242 }
243 return (0);
244}
245
246static void
247log_drvinit(void *unused)
248{
249
229 break;
230
231 case FIOSETOWN:
232 return (fsetown(*(int *)data, &logsoftc.sc_sigio));
233
234 case FIOGETOWN:
235 *(int *)data = fgetown(&logsoftc.sc_sigio);
236 break;

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249 }
250 return (0);
251}
252
253static void
254log_drvinit(void *unused)
255{
256
257 cv_init(&log_wakeup, "klog");
258 callout_init_mtx(&logsoftc.sc_callout, &msgbuf_lock, 0);
250 make_dev(&log_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "klog");
251}
252
253SYSINIT(logdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,log_drvinit,NULL);
259 make_dev(&log_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "klog");
260}
261
262SYSINIT(logdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,log_drvinit,NULL);