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da7c5cc6 KM |
1 | /* |
2 | * Copyright (c) 1982 Regents of the University of California. | |
3 | * All rights reserved. The Berkeley software License Agreement | |
4 | * specifies the terms and conditions for redistribution. | |
5 | * | |
6 | * @(#)subr_log.c 6.5 (Berkeley) %G% | |
7 | */ | |
c45816fa RC |
8 | |
9 | /* | |
10 | * Error log buffer for kernel printf's. | |
11 | */ | |
12 | ||
94368568 JB |
13 | #include "param.h" |
14 | #include "dir.h" | |
15 | #include "user.h" | |
16 | #include "proc.h" | |
17 | #include "ioctl.h" | |
18 | #include "msgbuf.h" | |
19 | #include "file.h" | |
20 | #include "errno.h" | |
c45816fa RC |
21 | |
22 | #define LOG_RDPRI (PZERO + 1) | |
23 | ||
c45816fa RC |
24 | #define LOG_NBIO 0x02 |
25 | #define LOG_ASYNC 0x04 | |
26 | #define LOG_RDWAIT 0x08 | |
27 | ||
28 | struct logsoftc { | |
29 | int sc_state; /* see above for possibilities */ | |
30 | struct proc *sc_selp; /* process waiting on select call */ | |
31 | int sc_pgrp; /* process group for async I/O */ | |
32 | } logsoftc; | |
33 | ||
bd10af3f MK |
34 | int log_open; /* also used in log() */ |
35 | ||
18c9b20d RC |
36 | #ifdef LOGDEBUG |
37 | /*VARARGS1*/ | |
38 | xprintf(fmt, x1) | |
39 | char *fmt; | |
40 | unsigned x1; | |
41 | { | |
42 | ||
43 | prf(fmt, &x1, 1, (struct tty *)0); | |
44 | } | |
45 | #endif | |
46 | ||
c45816fa RC |
47 | logopen(dev) |
48 | dev_t dev; | |
49 | { | |
50 | ||
51 | #ifdef LOGDEBUG | |
18c9b20d | 52 | xprintf("logopen: dev=0x%x\n", dev); |
c45816fa | 53 | #endif |
bd10af3f | 54 | if (log_open) |
18c9b20d | 55 | return (EBUSY); |
bd10af3f | 56 | log_open = 1; |
c45816fa RC |
57 | logsoftc.sc_selp = 0; |
58 | logsoftc.sc_pgrp = u.u_procp->p_pgrp; | |
59 | /* | |
60 | * Potential race here with putchar() but since putchar should be | |
61 | * called by autoconf, msg_magic should be initialized by the time | |
62 | * we get here. | |
63 | */ | |
64 | if (msgbuf.msg_magic != MSG_MAGIC) { | |
65 | register int i; | |
66 | ||
67 | msgbuf.msg_magic = MSG_MAGIC; | |
68 | msgbuf.msg_bufx = msgbuf.msg_bufr = 0; | |
69 | for (i=0; i < MSG_BSIZE; i++) | |
70 | msgbuf.msg_bufc[i] = 0; | |
71 | } | |
18c9b20d RC |
72 | #ifdef LOGDEBUG |
73 | xprintf("logopen: bufx=%d, bufr=%d\n", msgbuf.msg_bufx, msgbuf.msg_bufr); | |
74 | #endif | |
75 | return (0); | |
c45816fa RC |
76 | } |
77 | ||
78 | logclose(dev, flag) | |
79 | dev_t dev; | |
80 | { | |
bd10af3f | 81 | log_open = 0; |
c45816fa RC |
82 | logsoftc.sc_state = 0; |
83 | logsoftc.sc_selp = 0; | |
84 | logsoftc.sc_pgrp = 0; | |
85 | #ifdef LOGDEBUG | |
18c9b20d | 86 | xprintf("logclose: dev=0x%x\n", dev); |
c45816fa RC |
87 | #endif |
88 | } | |
89 | ||
90 | logread(dev, uio) | |
91 | dev_t dev; | |
92 | struct uio *uio; | |
93 | { | |
94 | register long l; | |
95 | register u_int c; | |
96 | register struct iovec *iov; | |
97 | register int s; | |
98 | int error = 0; | |
99 | ||
100 | #ifdef LOGDEBUG | |
18c9b20d | 101 | xprintf("logread: dev=0x%x\n", dev); |
c45816fa RC |
102 | #endif |
103 | ||
104 | s = splhigh(); | |
105 | while (msgbuf.msg_bufr == msgbuf.msg_bufx) { | |
106 | if (logsoftc.sc_state & LOG_NBIO) { | |
107 | splx(s); | |
18c9b20d | 108 | return (EWOULDBLOCK); |
c45816fa RC |
109 | } |
110 | logsoftc.sc_state |= LOG_RDWAIT; | |
111 | sleep((caddr_t)&msgbuf, LOG_RDPRI); | |
112 | } | |
113 | splx(s); | |
114 | logsoftc.sc_state &= ~LOG_RDWAIT; | |
115 | ||
116 | while (uio->uio_resid > 0) { | |
117 | l = msgbuf.msg_bufx - msgbuf.msg_bufr; | |
118 | if (l < 0) | |
119 | l = MSG_BSIZE - msgbuf.msg_bufr; | |
120 | c = min((u_int) l, (u_int)uio->uio_resid); | |
18c9b20d RC |
121 | #ifdef LOGDEBUG |
122 | xprintf("logread: bufx=%d, bufr=%d, l=%d, c=%d\n", | |
123 | msgbuf.msg_bufx, msgbuf.msg_bufr, l, c); | |
124 | #endif | |
125 | if (c <= 0) | |
126 | break; | |
c45816fa RC |
127 | error = uiomove((caddr_t)&msgbuf.msg_bufc[msgbuf.msg_bufr], |
128 | (int)c, UIO_READ, uio); | |
129 | if (error) | |
130 | break; | |
131 | msgbuf.msg_bufr += c; | |
132 | if (msgbuf.msg_bufr < 0 || msgbuf.msg_bufr >= MSG_BSIZE) | |
133 | msgbuf.msg_bufr = 0; | |
134 | } | |
18c9b20d | 135 | return (error); |
c45816fa RC |
136 | } |
137 | ||
138 | logselect(dev, rw) | |
139 | dev_t dev; | |
140 | int rw; | |
141 | { | |
142 | int s = splhigh(); | |
143 | ||
144 | switch (rw) { | |
145 | ||
146 | case FREAD: | |
147 | if (msgbuf.msg_bufr != msgbuf.msg_bufx) | |
148 | goto win; | |
149 | #ifdef LOGDEBUG | |
150 | if (logsoftc.sc_selp) | |
18c9b20d | 151 | xprintf("logselect: collision\n"); |
c45816fa RC |
152 | #endif |
153 | logsoftc.sc_selp = u.u_procp; | |
154 | break; | |
155 | ||
156 | case FWRITE: | |
157 | #ifdef LOGDEBUG | |
18c9b20d | 158 | xprintf("logselect: FWRITE\n"); |
c45816fa RC |
159 | #endif |
160 | break; | |
161 | } | |
162 | splx(s); | |
18c9b20d | 163 | return (0); |
c45816fa RC |
164 | win: |
165 | splx(s); | |
18c9b20d | 166 | return (1); |
c45816fa RC |
167 | } |
168 | ||
169 | logwakeup() | |
170 | { | |
171 | ||
bd10af3f MK |
172 | if (!log_open) |
173 | return; | |
c45816fa RC |
174 | if (logsoftc.sc_selp) { |
175 | selwakeup(logsoftc.sc_selp, 0); | |
176 | logsoftc.sc_selp = 0; | |
177 | } | |
178 | if (logsoftc.sc_state & LOG_ASYNC) | |
179 | gsignal(logsoftc.sc_pgrp, SIGIO); | |
180 | if (logsoftc.sc_state & LOG_RDWAIT) { | |
181 | wakeup((caddr_t)&msgbuf); | |
182 | logsoftc.sc_state &= ~LOG_RDWAIT; | |
183 | } | |
184 | } | |
185 | ||
186 | /*ARGSUSED*/ | |
187 | logioctl(com, data, flag) | |
188 | caddr_t data; | |
189 | { | |
190 | long l; | |
191 | int s; | |
192 | ||
193 | switch (com) { | |
194 | ||
195 | /* return number of characters immediately available */ | |
196 | case FIONREAD: | |
197 | s = splhigh(); | |
198 | l = msgbuf.msg_bufx - msgbuf.msg_bufr; | |
199 | splx(s); | |
200 | if (l < 0) | |
201 | l += MSG_BSIZE; | |
202 | *(off_t *)data = l; | |
203 | break; | |
204 | ||
205 | case FIONBIO: | |
206 | if (*(int *)data) | |
207 | logsoftc.sc_state |= LOG_NBIO; | |
208 | else | |
209 | logsoftc.sc_state &= ~LOG_NBIO; | |
210 | break; | |
211 | ||
212 | case FIOASYNC: | |
213 | if (*(int *)data) | |
214 | logsoftc.sc_state |= LOG_ASYNC; | |
215 | else | |
216 | logsoftc.sc_state &= ~LOG_ASYNC; | |
217 | break; | |
218 | ||
219 | case TIOCSPGRP: | |
220 | logsoftc.sc_pgrp = *(int *)data; | |
221 | break; | |
222 | ||
223 | case TIOCGPGRP: | |
224 | *(int *)data = logsoftc.sc_pgrp; | |
225 | break; | |
226 | ||
227 | default: | |
18c9b20d | 228 | return (-1); |
c45816fa | 229 | } |
18c9b20d | 230 | return (0); |
c45816fa | 231 | } |