qemu/trace/control.c

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6.3 KiB
C
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/*
* Interface for configuring and controlling the state of tracing events.
*
* Copyright (C) 2011-2016 Lluís Vilanova <vilanova@ac.upc.edu>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/
#include "qemu/osdep.h"
#include "trace/control.h"
#include "qemu/help_option.h"
#ifdef CONFIG_TRACE_SIMPLE
#include "trace/simple.h"
#endif
#ifdef CONFIG_TRACE_FTRACE
#include "trace/ftrace.h"
#endif
#ifdef CONFIG_TRACE_LOG
#include "qemu/log.h"
#endif
#ifdef CONFIG_TRACE_SYSLOG
#include <syslog.h>
#endif
#include "qapi/error.h"
#include "qemu/error-report.h"
#include "qemu/config-file.h"
#include "monitor/monitor.h"
int trace_events_enabled_count;
QemuOptsList qemu_trace_opts = {
.name = "trace",
.implied_opt_name = "enable",
.head = QTAILQ_HEAD_INITIALIZER(qemu_trace_opts.head),
.desc = {
{
.name = "enable",
.type = QEMU_OPT_STRING,
},
{
.name = "events",
.type = QEMU_OPT_STRING,
},{
.name = "file",
.type = QEMU_OPT_STRING,
},
{ /* end of list */ }
},
};
TraceEvent *trace_event_name(const char *name)
{
assert(name != NULL);
TraceEventIter iter;
TraceEvent *ev;
trace_event_iter_init(&iter, NULL);
while ((ev = trace_event_iter_next(&iter)) != NULL) {
if (strcmp(trace_event_get_name(ev), name) == 0) {
return ev;
}
}
return NULL;
}
static bool pattern_glob(const char *pat, const char *ev)
{
while (*pat != '\0' && *ev != '\0') {
if (*pat == *ev) {
pat++;
ev++;
}
else if (*pat == '*') {
if (pattern_glob(pat, ev+1)) {
return true;
} else if (pattern_glob(pat+1, ev)) {
return true;
} else {
return false;
}
} else {
return false;
}
}
while (*pat == '*') {
pat++;
}
if (*pat == '\0' && *ev == '\0') {
return true;
} else {
return false;
}
}
void trace_event_iter_init(TraceEventIter *iter, const char *pattern)
{
iter->event = 0;
iter->pattern = pattern;
}
TraceEvent *trace_event_iter_next(TraceEventIter *iter)
{
while (trace_events[iter->event] != NULL) {
TraceEvent *ev = trace_events[iter->event];
iter->event++;
if (!iter->pattern ||
pattern_glob(iter->pattern,
trace_event_get_name(ev))) {
return ev;
}
}
return NULL;
}
void trace_list_events(void)
{
TraceEventIter iter;
TraceEvent *ev;
trace_event_iter_init(&iter, NULL);
while ((ev = trace_event_iter_next(&iter)) != NULL) {
fprintf(stderr, "%s\n", trace_event_get_name(ev));
}
}
static void do_trace_enable_events(const char *line_buf)
{
const bool enable = ('-' != line_buf[0]);
const char *line_ptr = enable ? line_buf : line_buf + 1;
TraceEventIter iter;
TraceEvent *ev;
bool is_pattern = trace_event_is_pattern(line_ptr);
trace_event_iter_init(&iter, line_ptr);
while ((ev = trace_event_iter_next(&iter)) != NULL) {
if (!trace_event_get_state_static(ev)) {
if (!is_pattern) {
error_report("WARNING: trace event '%s' is not traceable",
line_ptr);
return;
}
continue;
}
/* start tracing */
trace_event_set_state_dynamic(ev, enable);
if (!is_pattern) {
return;
}
}
if (!is_pattern) {
error_report("WARNING: trace event '%s' does not exist",
line_ptr);
}
}
void trace_enable_events(const char *line_buf)
{
if (is_help_option(line_buf)) {
trace_list_events();
if (cur_mon == NULL) {
exit(0);
}
} else {
do_trace_enable_events(line_buf);
}
}
static void trace_init_events(const char *fname)
{
Location loc;
FILE *fp;
char line_buf[1024];
size_t line_idx = 0;
if (fname == NULL) {
return;
}
loc_push_none(&loc);
loc_set_file(fname, 0);
fp = fopen(fname, "r");
if (!fp) {
error_report("%s", strerror(errno));
exit(1);
}
while (fgets(line_buf, sizeof(line_buf), fp)) {
loc_set_file(fname, ++line_idx);
size_t len = strlen(line_buf);
if (len > 1) { /* skip empty lines */
line_buf[len - 1] = '\0';
if ('#' == line_buf[0]) { /* skip commented lines */
continue;
}
trace_enable_events(line_buf);
}
}
if (fclose(fp) != 0) {
loc_set_file(fname, 0);
error_report("%s", strerror(errno));
exit(1);
}
loc_pop(&loc);
}
void trace_init_file(const char *file)
{
#ifdef CONFIG_TRACE_SIMPLE
st_set_trace_file(file);
#elif defined CONFIG_TRACE_LOG
/* If both the simple and the log backends are enabled, "-trace file"
* only applies to the simple backend; use "-D" for the log backend.
*/
if (file) {
qemu_set_log_filename(file, &error_fatal);
}
#else
if (file) {
fprintf(stderr, "error: -trace file=...: "
"option not supported by the selected tracing backends\n");
exit(1);
}
#endif
}
bool trace_init_backends(void)
{
#ifdef CONFIG_TRACE_SIMPLE
if (!st_init()) {
fprintf(stderr, "failed to initialize simple tracing backend.\n");
return false;
}
#endif
#ifdef CONFIG_TRACE_FTRACE
if (!ftrace_init()) {
fprintf(stderr, "failed to initialize ftrace backend.\n");
return false;
}
#endif
#ifdef CONFIG_TRACE_SYSLOG
openlog(NULL, LOG_PID, LOG_DAEMON);
#endif
return true;
}
char *trace_opt_parse(const char *optarg)
{
char *trace_file;
QemuOpts *opts = qemu_opts_parse_noisily(qemu_find_opts("trace"),
optarg, true);
if (!opts) {
exit(1);
}
if (qemu_opt_get(opts, "enable")) {
trace_enable_events(qemu_opt_get(opts, "enable"));
}
trace_init_events(qemu_opt_get(opts, "events"));
trace_file = g_strdup(qemu_opt_get(opts, "file"));
qemu_opts_del(opts);
return trace_file;
}