#include "trace.h"
#include "trace_output.h"
+static bool kill_ftrace_graph;
+
+/**
+ * ftrace_graph_is_dead - returns true if ftrace_graph_stop() was called
+ *
+ * ftrace_graph_stop() is called when a severe error is detected in
+ * the function graph tracing. This function is called by the critical
+ * paths of function graph to keep those paths from doing any more harm.
+ */
+bool ftrace_graph_is_dead(void)
+{
+ return kill_ftrace_graph;
+}
+
+/**
+ * ftrace_graph_stop - set to permanently disable function graph tracincg
+ *
+ * In case of an error int function graph tracing, this is called
+ * to try to keep function graph tracing from causing any more harm.
+ * Usually this is pretty severe and this is called to try to at least
+ * get a warning out to the user.
+ */
+void ftrace_graph_stop(void)
+{
+ kill_ftrace_graph = true;
+}
+
/* When set, irq functions will be ignored */
static int ftrace_graph_skip_irqs;
unsigned long long calltime;
int index;
+ if (unlikely(ftrace_graph_is_dead()))
+ return -EBUSY;
+
if (!current->ret_stack)
return -EBUSY;
return ret;
}
-int trace_graph_thresh_entry(struct ftrace_graph_ent *trace)
+static int trace_graph_thresh_entry(struct ftrace_graph_ent *trace)
{
if (tracing_thresh)
return 1;
smp_mb();
}
-void trace_graph_thresh_return(struct ftrace_graph_ret *trace)
+static void trace_graph_thresh_return(struct ftrace_graph_ret *trace)
{
if (tracing_thresh &&
(trace->rettime - trace->calltime < tracing_thresh))
unregister_ftrace_graph();
}
+static int graph_trace_update_thresh(struct trace_array *tr)
+{
+ graph_trace_reset(tr);
+ return graph_trace_init(tr);
+}
+
static int max_bytes_for_cpu;
static enum print_line_t
seq_printf(s, " | | | |\n");
}
-void print_graph_headers(struct seq_file *s)
+static void print_graph_headers(struct seq_file *s)
{
print_graph_headers_flags(s, tracer_flags.val);
}
static struct tracer graph_trace __tracer_data = {
.name = "function_graph",
+ .update_thresh = graph_trace_update_thresh,
.open = graph_trace_open,
.pipe_open = graph_trace_open,
.close = graph_trace_close,