Commit 1a414428 authored by Steven Rostedt (Red Hat)'s avatar Steven Rostedt (Red Hat) Committed by Steven Rostedt
Browse files

tracing/fgraph: Have wakeup and irqsoff tracers ignore graph functions too 



Currently both the wakeup and irqsoff traces do not handle set_graph_notrace
well. The ftrace infrastructure will ignore the return paths of all
functions leaving them hanging without an end:

  # echo '*spin*' > set_graph_notrace
  # cat trace
  [...]
          _raw_spin_lock() {
            preempt_count_add() {
            do_raw_spin_lock() {
          update_rq_clock();

Where the '*spin*' functions should have looked like this:

          _raw_spin_lock() {
            preempt_count_add();
            do_raw_spin_lock();
          }
          update_rq_clock();

Instead, have the wakeup and irqsoff tracers ignore the functions that are
set by the set_graph_notrace like the function_graph tracer does. Move
the logic in the function_graph tracer into a header to allow wakeup and
irqsoff tracers to use it as well.

Cc: Namhyung Kim <namhyung.kim@lge.com>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent 794de08a

kernel/trace/trace.h

+11 −0
Original line number Diff line number Diff line
@@ -846,6 +846,17 @@ static inline int ftrace_graph_notrace_addr(unsigned long addr) 
	return 0;

}

#endif /* CONFIG_DYNAMIC_FTRACE */



extern unsigned int fgraph_max_depth;



static inline bool ftrace_graph_ignore_func(struct ftrace_graph_ent *trace)

{

	/* trace it when it is-nested-in or is a function enabled. */

	return !(trace->depth || ftrace_graph_addr(trace->func)) ||

		(trace->depth < 0) ||

		(fgraph_max_depth && trace->depth >= fgraph_max_depth);

}



#else /* CONFIG_FUNCTION_GRAPH_TRACER */

static inline enum print_line_t

print_graph_function_flags(struct trace_iterator *iter, u32 flags)

kernel/trace/trace_functions_graph.c

+7 −7
Original line number Diff line number Diff line
@@ -65,7 +65,7 @@ struct fgraph_data { 


#define TRACE_GRAPH_INDENT	2



static unsigned int max_depth;

unsigned int fgraph_max_depth;



static struct tracer_opt trace_opts[] = {

	/* Display overruns? (for self-debug purpose) */
@@ -384,10 +384,10 @@ int trace_graph_entry(struct ftrace_graph_ent *trace) 
	if (!ftrace_trace_task(tr))

		return 0;



	/* trace it when it is-nested-in or is a function enabled. */

	if ((!(trace->depth || ftrace_graph_addr(trace->func)) ||

	     ftrace_graph_ignore_irqs()) || (trace->depth < 0) ||

	    (max_depth && trace->depth >= max_depth))

	if (ftrace_graph_ignore_func(trace))

		return 0;



	if (ftrace_graph_ignore_irqs())

		return 0;



	/*
@@ -1500,7 +1500,7 @@ graph_depth_write(struct file *filp, const char __user *ubuf, size_t cnt, 
	if (ret)

		return ret;



	max_depth = val;

	fgraph_max_depth = val;



	*ppos += cnt;
@@ -1514,7 +1514,7 @@ graph_depth_read(struct file *filp, char __user *ubuf, size_t cnt, 
	char buf[15]; /* More than enough to hold UINT_MAX + "\n"*/

	int n;



	n = sprintf(buf, "%d\n", max_depth);

	n = sprintf(buf, "%d\n", fgraph_max_depth);



	return simple_read_from_buffer(ubuf, cnt, ppos, buf, n);

}

kernel/trace/trace_irqsoff.c

+12 −0
Original line number Diff line number Diff line
@@ -175,6 +175,18 @@ static int irqsoff_graph_entry(struct ftrace_graph_ent *trace) 
	int ret;

	int pc;



	if (ftrace_graph_ignore_func(trace))

		return 0;

	/*

	 * Do not trace a function if it's filtered by set_graph_notrace.

	 * Make the index of ret stack negative to indicate that it should

	 * ignore further functions.  But it needs its own ret stack entry

	 * to recover the original index in order to continue tracing after

	 * returning from the function.

	 */

	if (ftrace_graph_notrace_addr(trace->func))

		return 1;



	if (!func_prolog_dec(tr, &data, &flags))

		return 0;

kernel/trace/trace_sched_wakeup.c

+12 −0
Original line number Diff line number Diff line
@@ -239,6 +239,18 @@ static int wakeup_graph_entry(struct ftrace_graph_ent *trace) 
	unsigned long flags;

	int pc, ret = 0;



	if (ftrace_graph_ignore_func(trace))

		return 0;

	/*

	 * Do not trace a function if it's filtered by set_graph_notrace.

	 * Make the index of ret stack negative to indicate that it should

	 * ignore further functions.  But it needs its own ret stack entry

	 * to recover the original index in order to continue tracing after

	 * returning from the function.

	 */

	if (ftrace_graph_notrace_addr(trace->func))

		return 1;



	if (!func_prolog_preempt_disable(tr, &data, &pc))

		return 0;

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