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v0.8.1
https://github.com/torvalds/linux
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Tip revision: 4fe89d07dcc2804c8b562f6c7896a45643d34b2f authored by Linus Torvalds on 02 October 2022, 21:09:07 UTC
Linux 6.0
Tip revision: 4fe89d0
func-filter-pid.tc
#!/bin/sh
# SPDX-License-Identifier: GPL-2.0
# description: ftrace - function pid filters
# requires: set_ftrace_pid set_ftrace_filter function:tracer
# flags: instance

# Make sure that function pid matching filter works.
# Also test it on an instance directory

do_function_fork=1

if [ ! -f options/function-fork ]; then
    do_function_fork=0
    echo "no option for function-fork found. Option will not be tested."
fi

read PID _ < /proc/self/stat

if [ $do_function_fork -eq 1 ]; then
    # default value of function-fork option
    orig_value=`grep function-fork trace_options`
fi

do_reset() {
    if [ $do_function_fork -eq 0 ]; then
	return
    fi

    echo $orig_value > trace_options
}

fail() { # msg
    do_reset
    echo $1
    exit_fail
}

do_test() {
    disable_tracing

    echo do_execve* > set_ftrace_filter
    echo $FUNCTION_FORK >> set_ftrace_filter

    echo $PID > set_ftrace_pid
    echo function > current_tracer

    if [ $do_function_fork -eq 1 ]; then
	# don't allow children to be traced
	echo nofunction-fork > trace_options
    fi

    enable_tracing
    yield

    count_pid=`cat trace | grep -v ^# | grep $PID | wc -l`
    count_other=`cat trace | grep -v ^# | grep -v $PID | wc -l`

    # count_other should be 0
    if [ $count_pid -eq 0 -o $count_other -ne 0 ]; then
	fail "PID filtering not working?"
    fi

    disable_tracing
    clear_trace

    if [ $do_function_fork -eq 0 ]; then
	return
    fi

    # allow children to be traced
    echo function-fork > trace_options

    enable_tracing
    yield

    count_pid=`cat trace | grep -v ^# | grep $PID | wc -l`
    count_other=`cat trace | grep -v ^# | grep -v $PID | wc -l`

    # count_other should NOT be 0
    if [ $count_pid -eq 0 -o $count_other -eq 0 ]; then
	fail "PID filtering not following fork?"
    fi
}

do_test
do_reset

exit 0
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