tools/testing/selftests/ftrace/test.d/ftrace/fgraph-filter-stack.tc

#!/bin/sh
# SPDX-License-Identifier: GPL-2.0
# description: ftrace - function graph filters with stack tracer

# Make sure that function graph filtering works, and is not
# affected by other tracers enabled (like stack tracer)

if ! grep -q function_graph available_tracers; then
    echo "no function graph tracer configured"
    exit_unsupported
fi

if [ ! -f set_ftrace_filter ]; then
    echo "set_ftrace_filter not found? Is dynamic ftrace not set?"
    exit_unsupported
fi

do_reset() {
    reset_tracer
    if [ -e /proc/sys/kernel/stack_tracer_enabled ]; then
	    echo 0 > /proc/sys/kernel/stack_tracer_enabled
    fi
    enable_tracing
    clear_trace
    echo > set_ftrace_filter
}

fail() { # msg
    do_reset
    echo $1
    exit $FAIL
}

disable_tracing
clear_trace;

# filter something, schedule is always good
if ! echo "schedule" > set_ftrace_filter; then
    # test for powerpc 64
    if ! echo ".schedule" > set_ftrace_filter; then
	fail "can not enable schedule filter"
    fi
fi

echo function_graph > current_tracer

if [ ! -f stack_trace ]; then
    echo "Stack tracer not configured"
    do_reset
    exit_unsupported;
fi

echo "Now testing with stack tracer"

echo 1 > /proc/sys/kernel/stack_tracer_enabled

disable_tracing
clear_trace
enable_tracing
sleep 1

count=`cat trace | grep '()' | grep -v schedule | wc -l`

if [ $count -ne 0 ]; then
    fail "Graph filtering not working with stack tracer?"
fi

# Make sure we did find something
count=`cat trace | grep 'schedule()' | wc -l` 
if [ $count -eq 0 ]; then
    fail "No schedule traces found?"
fi

echo 0 > /proc/sys/kernel/stack_tracer_enabled
clear_trace
sleep 1


count=`cat trace | grep '()' | grep -v schedule | wc -l`

if [ $count -ne 0 ]; then
    fail "Graph filtering not working after stack tracer disabled?"
fi

count=`cat trace | grep 'schedule()' | wc -l` 
if [ $count -eq 0 ]; then
    fail "No schedule traces found?"
fi

do_reset

exit 0