tools/bootconfig: Add a script to generates bootconfig from ftrace

#!/bin/sh

# SPDX-License-Identifier: GPL-2.0-only

usage() {

	echo "Dump boot-time tracing bootconfig from ftrace"

	echo "Usage: $0 [--debug] [ > BOOTCONFIG-FILE]"

	exit 1

}

DEBUG=

while [ x"$1" != x ]; do

	case "$1" in

	"--debug")

		DEBUG=$1;;

	-*)

		usage

		;;

	esac

	shift 1

done

if [ x"$DEBUG" != x ]; then

	set -x

fi

TRACEFS=`grep -m 1 -w tracefs /proc/mounts | cut -f 2 -d " "`

if [ -z "$TRACEFS" ]; then

	if ! grep -wq debugfs /proc/mounts; then

		echo "Error: No tracefs/debugfs was mounted."

		exit 1

	fi

	TRACEFS=`grep -m 1 -w debugfs /proc/mounts | cut -f 2 -d " "`/tracing

	if [ ! -d $TRACEFS ]; then

		echo "Error: ftrace is not enabled on this kernel." 1>&2

		exit 1

	fi

fi

######## main #########

set -e

emit_kv() { # key =|+= value

	echo "$@"

}

global_options() {

	val=`cat $TRACEFS/max_graph_depth`

	[ $val != 0 ] && emit_kv kernel.fgraph_max_depth = $val

	if grep -qv "^#" $TRACEFS/set_graph_function $TRACEFS/set_graph_notrace ; then

		cat 1>&2 << EOF

# WARN: kernel.fgraph_filters and kernel.fgraph_notrace are not supported, since the wild card expression was expanded and lost from memory.

EOF

	fi

}

kprobe_event_options() {

	cat $TRACEFS/kprobe_events | while read p args; do

		case $p in

		r*)

		cat 1>&2 << EOF

# WARN: A return probe found but it is not supported by bootconfig. Skip it.

EOF

		continue;;

		esac

		p=${p#*:}

		event=${p#*/}

		group=${p%/*}

		if [ $group != "kprobes" ]; then

			cat 1>&2 << EOF

# WARN: kprobes group name $group is changed to "kprobes" for bootconfig.

EOF

		fi

		emit_kv $PREFIX.event.kprobes.$event.probes += $args

	done

}

synth_event_options() {

	cat $TRACEFS/synthetic_events | while read event fields; do

		emit_kv $PREFIX.event.synthetic.$event.fields = `echo $fields | sed "s/;/,/g"`

	done

}

# Variables resolver

DEFINED_VARS=

UNRESOLVED_EVENTS=

defined_vars() { # event-dir

	grep "^hist" $1/trigger | grep -o ':[a-zA-Z0-9]*='

}

referred_vars() {

	grep "^hist" $1/trigger | grep -o '$[a-zA-Z0-9]*'

}

per_event_options() { # event-dir

	evdir=$1

	# Check the special event which has no filter and no trigger

	[ ! -f $evdir/filter ] && return

	if grep -q "^hist:" $evdir/trigger; then

		# hist action can refer the undefined variables

		__vars=`defined_vars $evdir`

		for v in `referred_vars $evdir`; do

			if echo $DEFINED_VARS $__vars | grep -vqw ${v#$}; then

				# $v is not defined yet, defer it

				UNRESOLVED_EVENTS="$UNRESOLVED_EVENTS $evdir"

				return;

			fi

		done

		DEFINED_VARS="$DEFINED_VARS "`defined_vars $evdir`

	fi

	grep -v "^#" $evdir/trigger | while read action active; do

		emit_kv $PREFIX.event.$group.$event.actions += \'$action\'

	done

	# enable is not checked; this is done by set_event in the instance.

	val=`cat $evdir/filter`

	if [ "$val" != "none" ]; then

		emit_kv $PREFIX.event.$group.$event.filter = "$val"

	fi

}

retry_unresolved() {

	unresolved=$UNRESOLVED_EVENTS

	UNRESOLVED_EVENTS=

	for evdir in $unresolved; do

		event=${evdir##*/}

		group=${evdir%/*}; group=${group##*/}

		per_event_options $evdir

	done

}

event_options() {

	# PREFIX and INSTANCE must be set

	if [ $PREFIX = "ftrace" ]; then

		# define the dynamic events

		kprobe_event_options

		synth_event_options

	fi

	for group in `ls $INSTANCE/events/` ; do

		[ ! -d $INSTANCE/events/$group ] && continue

		for event in `ls $INSTANCE/events/$group/` ;do

			[ ! -d $INSTANCE/events/$group/$event ] && continue

			per_event_options $INSTANCE/events/$group/$event

		done

	done

	retry=0

	while [ $retry -lt 3 ]; do

		retry_unresolved

		retry=$((retry + 1))

	done

	if [ "$UNRESOLVED_EVENTS" ]; then

		cat 1>&2 << EOF

! ERROR: hist triggers in $UNRESOLVED_EVENTS use some undefined variables.

EOF

	fi

}

is_default_trace_option() { # option

grep -qw $1 << EOF

print-parent

nosym-offset

nosym-addr

noverbose

noraw

nohex

nobin

noblock

trace_printk

annotate

nouserstacktrace

nosym-userobj

noprintk-msg-only

context-info

nolatency-format

record-cmd

norecord-tgid

overwrite

nodisable_on_free

irq-info

markers

noevent-fork

nopause-on-trace

function-trace

nofunction-fork

nodisplay-graph

nostacktrace

notest_nop_accept

notest_nop_refuse

EOF

}

instance_options() { # [instance-name]

	if [ $# -eq 0 ]; then

		PREFIX="ftrace"

		INSTANCE=$TRACEFS

	else

		PREFIX="ftrace.instance.$1"

		INSTANCE=$TRACEFS/instances/$1

	fi

	val=

	for i in `cat $INSTANCE/trace_options`; do

		is_default_trace_option $i && continue

		val="$val, $i"

	done

	[ "$val" ] && emit_kv $PREFIX.options = "${val#,}"

	val="local"

	for i in `cat $INSTANCE/trace_clock` ; do

		[ "${i#*]}" ] && continue

		i=${i%]}; val=${i#[}

	done

	[ $val != "local" ] && emit_kv $PREFIX.trace_clock = $val

	val=`cat $INSTANCE/buffer_size_kb`

	if echo $val | grep -vq "expanded" ; then

		emit_kv $PREFIX.buffer_size = $val"KB"

	fi

	if grep -q "is allocated" $INSTANCE/snapshot ; then

		emit_kv $PREFIX.alloc_snapshot

	fi

	val=`cat $INSTANCE/tracing_cpumask`

	if [ `echo $val | sed -e s/f//g`x != x ]; then

		emit_kv $PREFIX.cpumask = $val

	fi

	val=

	for i in `cat $INSTANCE/set_event`; do

		val="$val, $i"

	done

	[ "$val" ] && emit_kv $PREFIX.events = "${val#,}"

	val=`cat $INSTANCE/current_tracer`

	[ $val != nop ] && emit_kv $PREFIX.tracer = $val

	if grep -qv "^#" $INSTANCE/set_ftrace_filter $INSTANCE/set_ftrace_notrace; then

		cat 1>&2 << EOF

# WARN: kernel.ftrace.filters and kernel.ftrace.notrace are not supported, since the wild card expression was expanded and lost from memory.

EOF

	fi

	event_options

}

global_options

instance_options

for i in `ls $TRACEFS/instances` ; do

	instance_options $i

done