freebsd-nq/stand/libsa/tslog.c
Colin Percival 242923eb84 loader tslog: Don't use sprintf
Instead, append the log entry "manually".

MFC after:	1 week
Sponsored by:	https://www.patreon.com/cperciva
2021-09-24 20:23:37 -07:00

121 lines
3.2 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>
#if defined(__amd64__) || defined(__i386__)
#include <machine/cpufunc.h>
#elif defined(__aarch64__)
#include <machine/armreg.h>
#endif
#include <stand.h>
/* Buffer for holding tslog data in string format. */
static char * tslog_buf = NULL;
static size_t tslog_buflen = 0;
static size_t tslog_bufpos = 0;
static size_t
tsccat(char * buf, uint64_t tsc)
{
size_t len;
/* Handle upper digits. */
if (tsc >= 10)
len = tsccat(buf, tsc / 10);
else
len = 0;
/* Write the last digit. */
buf[len] = "0123456789"[tsc % 10];
/* Return the length written. */
return (len + 1);
}
void
tslog_setbuf(void * buf, size_t len)
{
tslog_buf = (char *)buf;
tslog_buflen = len;
tslog_bufpos = 0;
}
void
tslog_getbuf(void ** buf, size_t * len)
{
*buf = (void *)tslog_buf;
*len = tslog_bufpos;
}
void
tslog(const char * type, const char * f, const char * s)
{
#if defined(__amd64__) || defined(__i386__)
uint64_t tsc = rdtsc();
#elif defined(__aarch64__)
uint64_t tsc = READ_SPECIALREG(cntvct_el0);
#else
uint64_t tsc = 0;
#endif
/* If we have no buffer, do nothing. */
if (tslog_buf == NULL)
return;
/* Check that we have enough space. */
if (tslog_buflen - tslog_bufpos < 32 + strlen(type) + strlen(f) +
(s ? strlen(s) : 0))
return;
/* Append to existing buffer. */
strcpy(&tslog_buf[tslog_bufpos], "0x0 ");
tslog_bufpos += 4;
tslog_bufpos += tsccat(&tslog_buf[tslog_bufpos], tsc);
strcpy(&tslog_buf[tslog_bufpos], " ");
tslog_bufpos += 1;
strcpy(&tslog_buf[tslog_bufpos], type);
tslog_bufpos += strlen(type);
strcpy(&tslog_buf[tslog_bufpos], " ");
tslog_bufpos += 1;
strcpy(&tslog_buf[tslog_bufpos], f);
tslog_bufpos += strlen(f);
if (s != NULL) {
strcpy(&tslog_buf[tslog_bufpos], " ");
tslog_bufpos += 1;
strcpy(&tslog_buf[tslog_bufpos], s);
tslog_bufpos += strlen(s);
}
strcpy(&tslog_buf[tslog_bufpos], "\n");
tslog_bufpos += 1;
}