1#!/bin/bash
2# SPDX-License-Identifier: GPL-2.0-only
3# perf-with-kcore: use perf with a copy of kcore
4# Copyright (c) 2014, Intel Corporation.
5#
6
7set -e
8
9usage()
10{
11        echo "Usage: perf-with-kcore <perf sub-command> <perf.data directory> [<sub-command options> [ -- <workload>]]" >&2
12        echo "       <perf sub-command> can be record, script, report or inject" >&2
13        echo "   or: perf-with-kcore fix_buildid_cache_permissions" >&2
14        exit 1
15}
16
17find_perf()
18{
19	if [ -n "$PERF" ] ; then
20		return
21	fi
22	PERF=`which perf || true`
23	if [ -z "$PERF" ] ; then
24		echo "Failed to find perf" >&2
25	        exit 1
26	fi
27	if [ ! -x "$PERF" ] ; then
28		echo "Failed to find perf" >&2
29	        exit 1
30	fi
31	echo "Using $PERF"
32	"$PERF" version
33}
34
35copy_kcore()
36{
37	echo "Copying kcore"
38
39	if [ $EUID -eq 0 ] ; then
40		SUDO=""
41	else
42		SUDO="sudo"
43	fi
44
45	rm -f perf.data.junk
46	("$PERF" record -o perf.data.junk "${PERF_OPTIONS[@]}" -- sleep 60) >/dev/null 2>/dev/null &
47	PERF_PID=$!
48
49	# Need to make sure that perf has started
50	sleep 1
51
52	KCORE=$(($SUDO "$PERF" buildid-cache -v -f -k /proc/kcore >/dev/null) 2>&1)
53	case "$KCORE" in
54	"kcore added to build-id cache directory "*)
55		KCORE_DIR=${KCORE#"kcore added to build-id cache directory "}
56	;;
57	*)
58		kill $PERF_PID
59		wait >/dev/null 2>/dev/null || true
60		rm perf.data.junk
61		echo "$KCORE"
62		echo "Failed to find kcore" >&2
63		exit 1
64	;;
65	esac
66
67	kill $PERF_PID
68	wait >/dev/null 2>/dev/null || true
69	rm perf.data.junk
70
71	$SUDO cp -a "$KCORE_DIR" "$(pwd)/$PERF_DATA_DIR"
72	$SUDO rm -f "$KCORE_DIR/kcore"
73	$SUDO rm -f "$KCORE_DIR/kallsyms"
74	$SUDO rm -f "$KCORE_DIR/modules"
75	$SUDO rmdir "$KCORE_DIR"
76
77	KCORE_DIR_BASENAME=$(basename "$KCORE_DIR")
78	KCORE_DIR="$(pwd)/$PERF_DATA_DIR/$KCORE_DIR_BASENAME"
79
80	$SUDO chown $UID "$KCORE_DIR"
81	$SUDO chown $UID "$KCORE_DIR/kcore"
82	$SUDO chown $UID "$KCORE_DIR/kallsyms"
83	$SUDO chown $UID "$KCORE_DIR/modules"
84
85	$SUDO chgrp $GROUPS "$KCORE_DIR"
86	$SUDO chgrp $GROUPS "$KCORE_DIR/kcore"
87	$SUDO chgrp $GROUPS "$KCORE_DIR/kallsyms"
88	$SUDO chgrp $GROUPS "$KCORE_DIR/modules"
89
90	ln -s "$KCORE_DIR_BASENAME" "$PERF_DATA_DIR/kcore_dir"
91}
92
93fix_buildid_cache_permissions()
94{
95	if [ $EUID -ne 0 ] ; then
96		echo "This script must be run as root via sudo " >&2
97		exit 1
98	fi
99
100	if [ -z "$SUDO_USER" ] ; then
101		echo "This script must be run via sudo" >&2
102		exit 1
103	fi
104
105	USER_HOME=$(bash <<< "echo ~$SUDO_USER")
106
107	echo "Fixing buildid cache permissions"
108
109	find "$USER_HOME/.debug" -xdev -type d          ! -user "$SUDO_USER" -ls -exec chown    "$SUDO_USER" \{\} \;
110	find "$USER_HOME/.debug" -xdev -type f -links 1 ! -user "$SUDO_USER" -ls -exec chown    "$SUDO_USER" \{\} \;
111	find "$USER_HOME/.debug" -xdev -type l          ! -user "$SUDO_USER" -ls -exec chown -h "$SUDO_USER" \{\} \;
112
113	if [ -n "$SUDO_GID" ] ; then
114		find "$USER_HOME/.debug" -xdev -type d          ! -group "$SUDO_GID" -ls -exec chgrp    "$SUDO_GID" \{\} \;
115		find "$USER_HOME/.debug" -xdev -type f -links 1 ! -group "$SUDO_GID" -ls -exec chgrp    "$SUDO_GID" \{\} \;
116		find "$USER_HOME/.debug" -xdev -type l          ! -group "$SUDO_GID" -ls -exec chgrp -h "$SUDO_GID" \{\} \;
117	fi
118
119	echo "Done"
120}
121
122check_buildid_cache_permissions()
123{
124	if [ $EUID -eq 0 ] ; then
125		return
126	fi
127
128	PERMISSIONS_OK+=$(find "$HOME/.debug" -xdev -type d          ! -user "$USER" -print -quit)
129	PERMISSIONS_OK+=$(find "$HOME/.debug" -xdev -type f -links 1 ! -user "$USER" -print -quit)
130	PERMISSIONS_OK+=$(find "$HOME/.debug" -xdev -type l          ! -user "$USER" -print -quit)
131
132	PERMISSIONS_OK+=$(find "$HOME/.debug" -xdev -type d          ! -group "$GROUPS" -print -quit)
133	PERMISSIONS_OK+=$(find "$HOME/.debug" -xdev -type f -links 1 ! -group "$GROUPS" -print -quit)
134	PERMISSIONS_OK+=$(find "$HOME/.debug" -xdev -type l          ! -group "$GROUPS" -print -quit)
135
136	if [ -n "$PERMISSIONS_OK" ] ; then
137		echo "*** WARNING *** buildid cache permissions may need fixing" >&2
138	fi
139}
140
141record()
142{
143	echo "Recording"
144
145	if [ $EUID -ne 0 ] ; then
146
147		if [ "$(cat /proc/sys/kernel/kptr_restrict)" -ne 0 ] ; then
148			echo "*** WARNING *** /proc/sys/kernel/kptr_restrict prevents access to kernel addresses" >&2
149		fi
150
151		if echo "${PERF_OPTIONS[@]}" | grep -q ' -a \|^-a \| -a$\|^-a$\| --all-cpus \|^--all-cpus \| --all-cpus$\|^--all-cpus$' ; then
152			echo "*** WARNING *** system-wide tracing without root access will not be able to read all necessary information from /proc" >&2
153		fi
154
155		if echo "${PERF_OPTIONS[@]}" | grep -q 'intel_pt\|intel_bts\| -I\|^-I' ; then
156			if [ "$(cat /proc/sys/kernel/perf_event_paranoid)" -gt -1 ] ; then
157				echo "*** WARNING *** /proc/sys/kernel/perf_event_paranoid restricts buffer size and tracepoint (sched_switch) use" >&2
158			fi
159
160			if echo "${PERF_OPTIONS[@]}" | grep -q ' --per-thread \|^--per-thread \| --per-thread$\|^--per-thread$' ; then
161				true
162			elif echo "${PERF_OPTIONS[@]}" | grep -q ' -t \|^-t \| -t$\|^-t$' ; then
163				true
164			elif [ ! -r /sys/kernel/debug -o ! -x /sys/kernel/debug ] ; then
165				echo "*** WARNING *** /sys/kernel/debug permissions prevent tracepoint (sched_switch) use" >&2
166			fi
167		fi
168	fi
169
170	if [ -z "$1" ] ; then
171		echo "Workload is required for recording" >&2
172		usage
173	fi
174
175	if [ -e "$PERF_DATA_DIR" ] ; then
176		echo "'$PERF_DATA_DIR' exists" >&2
177		exit 1
178	fi
179
180	find_perf
181
182	mkdir "$PERF_DATA_DIR"
183
184	echo "$PERF record -o $PERF_DATA_DIR/perf.data ${PERF_OPTIONS[@]} -- $@"
185	"$PERF" record -o "$PERF_DATA_DIR/perf.data" "${PERF_OPTIONS[@]}" -- "$@" || true
186
187	if rmdir "$PERF_DATA_DIR" > /dev/null 2>/dev/null ; then
188		exit 1
189	fi
190
191	copy_kcore
192
193	echo "Done"
194}
195
196subcommand()
197{
198	find_perf
199	check_buildid_cache_permissions
200	echo "$PERF $PERF_SUB_COMMAND -i $PERF_DATA_DIR/perf.data --kallsyms=$PERF_DATA_DIR/kcore_dir/kallsyms $@"
201	"$PERF" $PERF_SUB_COMMAND -i "$PERF_DATA_DIR/perf.data" "--kallsyms=$PERF_DATA_DIR/kcore_dir/kallsyms" "$@"
202}
203
204if [ "$1" = "fix_buildid_cache_permissions" ] ; then
205	fix_buildid_cache_permissions
206	exit 0
207fi
208
209PERF_SUB_COMMAND=$1
210PERF_DATA_DIR=$2
211shift || true
212shift || true
213
214if [ -z "$PERF_SUB_COMMAND" ] ; then
215	usage
216fi
217
218if [ -z "$PERF_DATA_DIR" ] ; then
219	usage
220fi
221
222case "$PERF_SUB_COMMAND" in
223"record")
224	while [ "$1" != "--" ] ; do
225		PERF_OPTIONS+=("$1")
226		shift || break
227	done
228	if [ "$1" != "--" ] ; then
229		echo "Options and workload are required for recording" >&2
230		usage
231	fi
232	shift
233	record "$@"
234;;
235"script")
236	subcommand "$@"
237;;
238"report")
239	subcommand "$@"
240;;
241"inject")
242	subcommand "$@"
243;;
244*)
245	usage
246;;
247esac
248