Commit 6479325e authored by Steven Rostedt's avatar Steven Rostedt Committed by Steven Rostedt (Google)
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tracing: Have function graph tracer option funcgraph-irqs be per instance 

Currently the option to trace interrupts in the function graph tracer is
global when the interface is per-instance. Changing the value in one
instance will affect the results of another instance that is also running
the function graph tracer. This can lead to confusing results.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://patch.msgid.link/20251114192318.613867934@kernel.org


Fixes: c132be2c ("function_graph: Have the instances use their own ftrace_ops for filtering")
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
parent 97e047f4

kernel/trace/trace_functions_graph.c

+31 −10
Original line number Diff line number Diff line
@@ -16,7 +16,7 @@ 
#include "trace.h"

#include "trace_output.h"



/* When set, irq functions will be ignored */

/* When set, irq functions might be ignored */

static int ftrace_graph_skip_irqs;



struct fgraph_cpu_data {
@@ -190,11 +190,14 @@ int __trace_graph_retaddr_entry(struct trace_array *tr, 
}

#endif



static inline int ftrace_graph_ignore_irqs(void)

static inline int ftrace_graph_ignore_irqs(struct trace_array *tr)

{

	if (!ftrace_graph_skip_irqs || trace_recursion_test(TRACE_IRQ_BIT))

		return 0;



	if (tracer_flags_is_set(tr, TRACE_GRAPH_PRINT_IRQS))

		return 0;



	return in_hardirq();

}
@@ -238,7 +241,7 @@ static int graph_entry(struct ftrace_graph_ent *trace, 
	if (ftrace_graph_ignore_func(gops, trace))

		return 0;



	if (ftrace_graph_ignore_irqs())

	if (ftrace_graph_ignore_irqs(tr))

		return 0;



	if (fgraph_sleep_time) {
@@ -451,6 +454,9 @@ static int graph_trace_init(struct trace_array *tr) 
	else

		tr->gops->retfunc = trace_graph_return;



	if (!tracer_flags_is_set(tr, TRACE_GRAPH_PRINT_IRQS))

		ftrace_graph_skip_irqs++;



	/* Make gops functions visible before we start tracing */

	smp_mb();
@@ -468,10 +474,6 @@ static int ftrace_graph_trace_args(struct trace_array *tr, int set) 
{

	trace_func_graph_ent_t entry;



	/* Do nothing if the current tracer is not this tracer */

	if (tr->current_trace != &graph_trace)

		return 0;



	if (set)

		entry = trace_graph_entry_args;

	else
@@ -492,6 +494,11 @@ static int ftrace_graph_trace_args(struct trace_array *tr, int set) 


static void graph_trace_reset(struct trace_array *tr)

{

	if (!tracer_flags_is_set(tr, TRACE_GRAPH_PRINT_IRQS))

		ftrace_graph_skip_irqs--;

	if (WARN_ON_ONCE(ftrace_graph_skip_irqs < 0))

		ftrace_graph_skip_irqs = 0;



	tracing_stop_cmdline_record();

	unregister_ftrace_graph(tr->gops);

}
@@ -1617,15 +1624,29 @@ void graph_trace_close(struct trace_iterator *iter) 
static int

func_graph_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set)

{

	if (bit == TRACE_GRAPH_PRINT_IRQS)

		ftrace_graph_skip_irqs = !set;



	if (bit == TRACE_GRAPH_SLEEP_TIME)

		ftrace_graph_sleep_time_control(set);



	if (bit == TRACE_GRAPH_GRAPH_TIME)

		ftrace_graph_graph_time_control(set);



	/* Do nothing if the current tracer is not this tracer */

	if (tr->current_trace != &graph_trace)

		return 0;



	/* Do nothing if already set. */

	if (!!set == !!(tr->current_trace_flags->val & bit))

		return 0;



	if (bit == TRACE_GRAPH_PRINT_IRQS) {

		if (set)

			ftrace_graph_skip_irqs--;

		else

			ftrace_graph_skip_irqs++;

		if (WARN_ON_ONCE(ftrace_graph_skip_irqs < 0))

			ftrace_graph_skip_irqs = 0;

	}



	if (bit == TRACE_GRAPH_ARGS)

		return ftrace_graph_trace_args(tr, set);