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/*
* Copyright (C) 2010 Stefan Hajnoczi <stefanha@gmail.com>.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
FILE_LICENCE ( GPL2_OR_LATER );
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <ipxe/init.h>
#include <ipxe/uaccess.h>
/** @file
*
* Function trace recorder for crash and hang debugging
*
*/
enum {
/** Constant for identifying valid trace buffers */
fnrec_magic = 'f' << 24 | 'n' << 16 | 'r' << 8 | 'e',
/** Trace buffer length */
fnrec_buffer_length = 4096 / sizeof ( unsigned long ),
};
/** A trace buffer */
struct fnrec_buffer {
/** Constant for identifying valid trace buffers */
uint32_t magic;
/** Next trace buffer entry to fill */
uint32_t idx;
/** Function address trace buffer */
unsigned long data[fnrec_buffer_length];
};
/** The trace buffer */
static struct fnrec_buffer *fnrec_buffer;
/**
* Test whether the trace buffer is valid
*
* @ret is_valid Buffer is valid
*/
static int fnrec_is_valid ( void ) {
return fnrec_buffer && fnrec_buffer->magic == fnrec_magic;
}
/**
* Reset the trace buffer and clear entries
*/
static void fnrec_reset ( void ) {
memset ( fnrec_buffer, 0, sizeof ( *fnrec_buffer ) );
fnrec_buffer->magic = fnrec_magic;
}
/**
* Write a value to the end of the buffer if it is not a repetition
*
* @v l Value to append
*/
static void fnrec_append_unique ( unsigned long l ) {
static unsigned long lastval;
uint32_t idx = fnrec_buffer->idx;
/* Avoid recording the same value repeatedly */
if ( l == lastval )
return;
fnrec_buffer->data[idx] = l;
fnrec_buffer->idx = ( idx + 1 ) % fnrec_buffer_length;
lastval = l;
}
/**
* Print the contents of the trace buffer in chronological order
*/
static void fnrec_dump ( void ) {
size_t i;
if ( !fnrec_is_valid() ) {
printf ( "fnrec buffer not found\n" );
return;
}
printf ( "fnrec buffer dump:\n" );
for ( i = 0; i < fnrec_buffer_length; i++ ) {
unsigned long l = fnrec_buffer->data[
( fnrec_buffer->idx + i ) % fnrec_buffer_length];
printf ( "%08lx%c", l, i % 8 == 7 ? '\n' : ' ' );
}
}
/**
* Function tracer initialisation function
*/
static void fnrec_init ( void ) {
/* Hardcoded to 17 MB */
fnrec_buffer = phys_to_virt ( 17 * 1024 * 1024 );
fnrec_dump();
fnrec_reset();
}
struct init_fn fnrec_init_fn __init_fn ( INIT_NORMAL ) = {
.initialise = fnrec_init,
};
/*
* These functions are called from every C function. The compiler inserts
* these calls when -finstrument-functions is used.
*/
void __cyg_profile_func_enter ( void *called_fn, void *call_site __unused ) {
if ( fnrec_is_valid() )
fnrec_append_unique ( ( unsigned long ) called_fn );
}
void __cyg_profile_func_exit ( void *called_fn __unused, void *call_site __unused ) {
}
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