/*
* Pretty much the same than for the function tracer from which the selftest
* has been borrowed.
*/
__init int
trace_selftest_startup_function_graph(struct tracer *trace,
struct trace_array *tr)
{
int ret;
unsigned long count;
#ifdef CONFIG_DYNAMIC_FTRACE
if (ftrace_filter_param) {
printk(KERN_CONT " ... kernel command line filter set: force PASS ... ");
return 0;
}
#endif
/*
* Simulate the init() callback but we attach a watchdog callback
* to detect and recover from possible hangs
*/
tracing_reset_online_cpus(&tr->trace_buffer);
set_graph_array(tr);
ret = register_ftrace_graph(&fgraph_ops);
if (ret) {
warn_failed_init_tracer(trace, ret);
goto out;
}
tracing_start_cmdline_record();
/* Sleep for a 1/10 of a second */
msleep(100);
/* Have we just recovered from a hang? */
if (graph_hang_thresh > GRAPH_MAX_FUNC_TEST) {
tracing_selftest_disabled = true;
ret = -1;
goto out;
}
tracing_stop();
/* check the trace buffer */
ret = trace_test_buffer(&tr->trace_buffer, &count);
trace->reset(tr);
tracing_start();
if (!ret && !count) {
printk(KERN_CONT ".. no entries found ..");
ret = -1;
goto out;
}
/* Don't test dynamic tracing, the function tracer already did */
out:
/* Stop it if we failed */
if (ret)
ftrace_graph_stop();
return ret;
}
int
trace_selftest_startup_function_graph(struct tracer *trace,
struct trace_array *tr)
{
int ret;
unsigned long count;
/*
*/
tracing_reset_online_cpus(tr);
set_graph_array(tr);
ret = register_ftrace_graph(&trace_graph_return,
&trace_graph_entry_watchdog);
if (ret) {
warn_failed_init_tracer(trace, ret);
goto out;
}
tracing_start_cmdline_record();
/* */
msleep(100);
/* */
if (graph_hang_thresh > GRAPH_MAX_FUNC_TEST) {
tracing_selftest_disabled = true;
ret = -1;
goto out;
}
tracing_stop();
/* */
ret = trace_test_buffer(tr, &count);
trace->reset(tr);
tracing_start();
if (!ret && !count) {
printk(KERN_CONT ".. no entries found ..");
ret = -1;
goto out;
}
/* */
out:
/* */
if (ret)
ftrace_graph_stop();
return ret;
}
static int trace_graph_entry_watchdog(struct ftrace_graph_ent *trace)
{
if (unlikely(++graph_hang_thresh > GRAPH_MAX_FUNC_TEST)) {
ftrace_graph_stop();
printk(KERN_WARNING "BUG: Function graph tracer hang!\n");
if (ftrace_dump_on_oops)
__ftrace_dump(false);
return 0;
}
return trace_graph_entry(trace);
}
/* Wrap the real function entry probe to avoid possible hanging */
static int trace_graph_entry_watchdog(struct ftrace_graph_ent *trace)
{
/* This is harmlessly racy, we want to approximately detect a hang */
if (unlikely(++graph_hang_thresh > GRAPH_MAX_FUNC_TEST)) {
ftrace_graph_stop();
printk(KERN_WARNING "BUG: Function graph tracer hang!\n");
if (ftrace_dump_on_oops)
__ftrace_dump(false, DUMP_ALL);
return 0;
}
return trace_graph_entry(trace);
}
