source: trunk/minix/drivers/log/diag.c@ 20

Last change on this file since 20 was 9, checked in by Mattia Monga, 14 years ago

Minix 3.1.2a
File size: 3.6 KB
Line 
1/* This file handle diagnostic output that is directly sent to the LOG driver.
2 * This output can either be a kernel message (announced through a SYS_EVENT
3 * with a SIGKMESS in the signal set) or output from another system process
4 * (announced through a DIAGNOSTICS message).
5 *
6 * Changes:
7 * 21 July 2005: Created (Jorrit N. Herder)
8 */
9
10#include <stdio.h>
11#include <fcntl.h>
12
13#include "log.h"
14#include "../../kernel/const.h"
15#include "../../kernel/config.h"
16#include "../../kernel/type.h"
17
18/*==========================================================================*
19 * do_new_kmess *
20 *==========================================================================*/
21PUBLIC int do_new_kmess(m)
22message *m; /* notification message */
23{
24/* Notification for a new kernel message. */
25 struct kmessages kmess; /* entire kmess structure */
26 char print_buf[KMESS_BUF_SIZE]; /* copy new message here */
27 static int prev_next = 0;
28 int bytes;
29 int i, r;
30
31 if (m->m_source == TTY_PROC_NR)
32 {
33 message mess;
34
35 /* Ask TTY driver for log output */
36 mess.GETKM_PTR= (char *) &kmess;
37 mess.m_type = GET_KMESS;
38 r= sendrec(TTY_PROC_NR, &mess);
39 if (r == OK) r= mess.m_type;
40 if (r != OK)
41 {
42 report("LOG","couldn't get copy of kmessages from TTY", r);
43 return EDONTREPLY;
44 }
45 }
46 else
47 {
48 /* Try to get a fresh copy of the buffer with kernel messages. */
49 if ((r=sys_getkmessages(&kmess)) != OK) {
50 report("LOG","couldn't get copy of kmessages", r);
51 return EDONTREPLY;
52 }
53 }
54
55 /* Print only the new part. Determine how many new bytes there are with
56 * help of the current and previous 'next' index. Note that the kernel
57 * buffer is circular. This works fine if less then KMESS_BUF_SIZE bytes
58 * is new data; else we miss % KMESS_BUF_SIZE here.
59 * Check for size being positive, the buffer might as well be emptied!
60 */
61 if (kmess.km_size > 0) {
62 bytes = ((kmess.km_next + KMESS_BUF_SIZE) - prev_next) % KMESS_BUF_SIZE;
63 r=prev_next; /* start at previous old */
64 i=0;
65 while (bytes > 0) {
66 print_buf[i] = kmess.km_buf[(r%KMESS_BUF_SIZE)];
67 bytes --;
68 r ++;
69 i ++;
70 }
71 /* Now terminate the new message and save it in the log. */
72 print_buf[i] = 0;
73 log_append(print_buf, i);
74 }
75
76 /* Almost done, store 'next' so that we can determine what part of the
77 * kernel messages buffer to print next time a notification arrives.
78 */
79 prev_next = kmess.km_next;
80 return EDONTREPLY;
81}
82
83/*===========================================================================*
84 * do_diagnostics *
85 *===========================================================================*/
86PUBLIC int do_diagnostics(message *m)
87{
88/* The LOG server handles all diagnostic messages from servers and device
89 * drivers. It forwards the message to the TTY driver to display it to the
90 * user. It also saves a copy in a local buffer so that messages can be
91 * reviewed at a later time.
92 */
93 int proc_nr_e;
94 vir_bytes src;
95 int count;
96 char c;
97 int i = 0;
98 static char diagbuf[10240];
99
100 /* Change SELF to actual process number. */
101 if ((proc_nr_e = m->DIAG_ENDPT) == SELF)
102 m->DIAG_ENDPT = proc_nr_e = m->m_source;
103
104 /* Now also make a copy for the private buffer at the LOG server, so
105 * that the messages can be reviewed at a later time.
106 */
107 src = (vir_bytes) m->DIAG_PRINT_BUF;
108 count = m->DIAG_BUF_COUNT;
109 while (count > 0 && i < sizeof(diagbuf)-1) {
110 if (sys_datacopy(proc_nr_e, src, SELF, (vir_bytes) &c, 1) != OK)
111 break; /* stop copying on error */
112 src ++;
113 count --;
114 diagbuf[i++] = c;
115 }
116 log_append(diagbuf, i);
117
118 return OK;
119}
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