minix/drivers/log/diag.c

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/* This file handle diagnostic output that is directly sent to the LOG driver.
* This output can either be a kernel message (announced through a SYS_EVENT
* with a SIGKMESS in the signal set) or output from another system process
* (announced through a DIAGNOSTICS message).
*
* Changes:
* 21 July 2005: Created (Jorrit N. Herder)
*/
#include <stdio.h>
#include <fcntl.h>
#include "log.h"
#include "../../kernel/const.h"
#include "../../kernel/config.h"
#include "../../kernel/type.h"
/*==========================================================================*
* do_new_kmess *
*==========================================================================*/
PUBLIC int do_new_kmess(m)
message *m; /* notification message */
{
/* Notification for a new kernel message. */
struct kmessages kmess; /* entire kmess structure */
char print_buf[KMESS_BUF_SIZE]; /* copy new message here */
static int prev_next = 0;
int bytes;
int i, r;
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if (m->m_source == TTY_PROC_NR)
{
message mess;
/* Ask TTY driver for log output */
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mess.GETKM_PTR= (char *) &kmess;
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mess.m_type = GET_KMESS;
r= sendrec(TTY_PROC_NR, &mess);
if (r == OK) r= mess.m_type;
if (r != OK)
{
report("LOG","couldn't get copy of kmessages from TTY", r);
return EDONTREPLY;
}
}
else
{
/* Try to get a fresh copy of the buffer with kernel messages. */
if ((r=sys_getkmessages(&kmess)) != OK) {
report("LOG","couldn't get copy of kmessages", r);
return EDONTREPLY;
}
}
/* Print only the new part. Determine how many new bytes there are with
* help of the current and previous 'next' index. Note that the kernel
* buffer is circular. This works fine if less then KMESS_BUF_SIZE bytes
* is new data; else we miss % KMESS_BUF_SIZE here.
* Check for size being positive, the buffer might as well be emptied!
*/
if (kmess.km_size > 0) {
bytes = ((kmess.km_next + KMESS_BUF_SIZE) - prev_next) % KMESS_BUF_SIZE;
r=prev_next; /* start at previous old */
i=0;
while (bytes > 0) {
print_buf[i] = kmess.km_buf[(r%KMESS_BUF_SIZE)];
bytes --;
r ++;
i ++;
}
/* Now terminate the new message and save it in the log. */
print_buf[i] = 0;
log_append(print_buf, i);
}
/* Almost done, store 'next' so that we can determine what part of the
* kernel messages buffer to print next time a notification arrives.
*/
prev_next = kmess.km_next;
return EDONTREPLY;
}
/*===========================================================================*
* do_diagnostics *
*===========================================================================*/
PUBLIC int do_diagnostics(message *m)
{
/* The LOG server handles all diagnostic messages from servers and device
* drivers. It forwards the message to the TTY driver to display it to the
* user. It also saves a copy in a local buffer so that messages can be
* reviewed at a later time.
*/
int proc_nr_e;
vir_bytes src;
int count;
char c;
int i = 0;
static char diagbuf[10240];
/* Change SELF to actual process number. */
if ((proc_nr_e = m->DIAG_ENDPT) == SELF)
m->DIAG_ENDPT = proc_nr_e = m->m_source;
/* Now also make a copy for the private buffer at the LOG server, so
* that the messages can be reviewed at a later time.
*/
src = (vir_bytes) m->DIAG_PRINT_BUF;
count = m->DIAG_BUF_COUNT;
while (count > 0 && i < sizeof(diagbuf)-1) {
if (sys_datacopy(proc_nr_e, src, SELF, (vir_bytes) &c, 1) != OK)
break; /* stop copying on error */
src ++;
count --;
diagbuf[i++] = c;
}
log_append(diagbuf, i);
return OK;
}