freebsd-dev/stand/common/tslog.c
Colin Percival c8dfc327db stand/common: Add support for timestamp logging (tslog)
This adds tslog_init, which allocates a 2MB buffer for recording
timestamped events; and tslog_publish, which takes the buffer and
passes it to the kernel as a "preloaded module".  These functions
will be used in a later commit.

Reviewed by:	kevans
2021-06-20 20:09:43 -07:00

82 lines
2.6 KiB
C

/*-
* Copyright (c) 2021 Colin Percival
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <stand.h>
#include "bootstrap.h"
/* Buffer for holding tslog data in string format. */
#ifndef LOADER_TSLOGSIZE
#define LOADER_TSLOGSIZE (2 * 1024 * 1024)
#endif
int
tslog_init(void)
{
void * tslog_buf;
/* Allocate buffer and pass to libsa tslog code. */
if ((tslog_buf = malloc(LOADER_TSLOGSIZE)) == NULL)
return (-1);
tslog_setbuf(tslog_buf, LOADER_TSLOGSIZE);
/* Record this as when we entered the loader. */
TSRAW("ENTER", "loader", NULL);
return (0);
}
/*
* Pass our tslog buffer as a preloaded "module" to the kernel. This should
* be called as late as possible prior to the kernel being executed, since
* any timestamps logged after this is called will not be visible to the
* kernel.
*/
int
tslog_publish(void)
{
void * tslog_buf;
size_t tslog_bufpos;
/* Record a log entry for ending logging. */
TSRAW("EXIT", "loader", NULL);
/* Get the buffer and its current length. */
tslog_getbuf(&tslog_buf, &tslog_bufpos);
/* If we never allocated a buffer, return an error. */
if (tslog_buf == NULL)
return (-1);
/* Store the buffer where the kernel can read it. */
return (file_addbuf("TSLOG", "TSLOG data", tslog_bufpos, tslog_buf));
}