/*
* Simple trace backend
*
* Copyright IBM, Corp. 2010
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*
*/
#include <stdlib.h>
#include <stdint.h>
#include <stdio.h>
#include <time.h>
#include "trace.h"
/** Trace file header event ID */
#define HEADER_EVENT_ID (~(uint64_t)0) /* avoids conflicting with TraceEventIDs */
/** Trace file magic number */
#define HEADER_MAGIC 0xf2b177cb0aa429b4ULL
/** Trace file version number, bump if format changes */
#define HEADER_VERSION 0
/** Trace buffer entry */
typedef struct {
uint64_t event;
uint64_t timestamp_ns;
uint64_t x1;
uint64_t x2;
uint64_t x3;
uint64_t x4;
uint64_t x5;
uint64_t x6;
} TraceRecord;
enum {
TRACE_BUF_LEN = 64 * 1024 / sizeof(TraceRecord),
};
static TraceRecord trace_buf[TRACE_BUF_LEN];
static unsigned int trace_idx;
static FILE *trace_fp;
static char *trace_file_name = NULL;
static bool trace_file_enabled = false;
void st_print_trace_file_status(FILE *stream, int (*stream_printf)(FILE *stream, const char *fmt, ...))
{
stream_printf(stream, "Trace file \"%s\" %s.\n",
trace_file_name, trace_file_enabled ? "on" : "off");
}
static bool write_header(FILE *fp)
{
static const TraceRecord header = {
.event = HEADER_EVENT_ID,
.timestamp_ns = HEADER_MAGIC,
.x1 = HEADER_VERSION,
};
return fwrite(&header, sizeof header, 1, fp) == 1;
}
/**
* set_trace_file : To set the name of a trace file.
* @file : pointer to the name to be set.
* If NULL, set to the default name-<pid> set at config time.
*/
bool st_set_trace_file(const char *file)
{
st_set_trace_file_enabled(false);
free(trace_file_name);
if (!file) {
if (asprintf(&trace_file_name, CONFIG_TRACE_FILE, getpid()) < 0) {
trace_file_name = NULL;
return false;
}
} else {
if (asprintf(&trace_file_name, "%s", file) < 0) {
trace_file_name = NULL;
return false;
}
}
st_set_trace_file_enabled(true);
return true;
}
static void flush_trace_file(void)
{
/* If the trace file is not open yet, open it now */
if (!trace_fp) {
trace_fp = fopen(trace_file_name, "w");
if (!trace_fp) {
/* Avoid repeatedly trying to open file on failure */
trace_file_enabled = false;
return;
}
write_header(trace_fp);
}
if (trace_fp) {
size_t unused; /* for when fwrite(3) is declared warn_unused_result */
unused = fwrite(trace_buf, trace_idx * sizeof(trace_buf[0]), 1, trace_fp);
}
}
void st_flush_trace_buffer(void)
{
if (trace_file_enabled) {
flush_trace_file();
}
/* Discard written trace records */
trace_idx = 0;
}
void st_set_trace_file_enabled(bool enable)
{
if (enable == trace_file_enabled) {
return; /* no change */
}
/* Flush/discard trace buffer */
st_flush_trace_buffer();
/* To disable, close trace file */
if (!enable) {
fclose(trace_fp);
trace_fp = NULL;
}
trace_file_enabled = enable;
}
static void trace(TraceEventID event, uint64_t x1, uint64_t x2, uint64_t x3,
uint64_t x4, uint64_t x5, uint64_t x6)
{
TraceRecord *rec = &trace_buf[trace_idx];
struct timespec ts;
/* TODO Windows? It would be good to use qemu-timer here but that isn't
* linked into qemu-tools. Also we should avoid recursion in the tracing
* code, therefore it is useful to be self-contained.
*/
clock_gettime(CLOCK_MONOTONIC, &ts);
if (!trace_list[event].state) {
return;
}
rec->event = event;
rec->timestamp_ns = ts.tv_sec * 1000000000LL + ts.tv_nsec;
rec->x1 = x1;
rec->x2 = x2;
rec->x3 = x3;
rec->x4 = x4;
rec->x5 = x5;
rec->x6 = x6;
if (++trace_idx == TRACE_BUF_LEN) {
st_flush_trace_buffer();
}
}
void trace0(TraceEventID event)
{
trace(event, 0, 0, 0, 0, 0, 0);
}
void trace1(TraceEventID event, uint64_t x1)
{
trace(event, x1, 0, 0, 0, 0, 0);
}
void trace2(TraceEventID event, uint64_t x1, uint64_t x2)
{
trace(event, x1, x2, 0, 0, 0, 0);
}
void trace3(TraceEventID event, uint64_t x1, uint64_t x2, uint64_t x3)
{
trace(event, x1, x2, x3, 0, 0, 0);
}
void trace4(TraceEventID event, uint64_t x1, uint64_t x2, uint64_t x3, uint64_t x4)
{
trace(event, x1, x2, x3, x4, 0, 0);
}
void trace5(TraceEventID event, uint64_t x1, uint64_t x2, uint64_t x3, uint64_t x4, uint64_t x5)
{
trace(event, x1, x2, x3, x4, x5, 0);
}
void trace6(TraceEventID event, uint64_t x1, uint64_t x2, uint64_t x3, uint64_t x4, uint64_t x5, uint64_t x6)
{
trace(event, x1, x2, x3, x4, x5, x6);
}
/**
* Flush the trace buffer on exit
*/
static void __attribute__((constructor)) st_init(void)
{
atexit(st_flush_trace_buffer);
}
void st_print_trace(FILE *stream, int (*stream_printf)(FILE *stream, const char *fmt, ...))
{
unsigned int i;
for (i = 0; i < trace_idx; i++) {
stream_printf(stream, "Event %lu : %lx %lx %lx %lx %lx\n",
trace_buf[i].event, trace_buf[i].x1, trace_buf[i].x2,
trace_buf[i].x3, trace_buf[i].x4, trace_buf[i].x5);
}
}
void st_print_trace_events(FILE *stream, int (*stream_printf)(FILE *stream, const char *fmt, ...))
{
unsigned int i;
for (i = 0; i < NR_TRACE_EVENTS; i++) {
stream_printf(stream, "%s [Event ID %u] : state %u\n",
trace_list[i].tp_name, i, trace_list[i].state);
}
}
static TraceEvent* find_trace_event_by_name(const char *tname)
{
unsigned int i;
if (!tname) {
return NULL;
}
for (i = 0; i < NR_TRACE_EVENTS; i++) {
if (!strcmp(trace_list[i].tp_name, tname)) {
return &trace_list[i];
}
}
return NULL; /* indicates end of list reached without a match */
}
void st_change_trace_event_state(const char *tname, bool tstate)
{
TraceEvent *tp;
tp = find_trace_event_by_name(tname);
if (tp) {
tp->state = tstate;
}
}
