1#!/bin/bash
2# perf-with-kcore: use perf with a copy of kcore
3# Copyright (c) 2014, Intel Corporation.
4#
5# This program is free software; you can redistribute it and/or modify it
6# under the terms and conditions of the GNU General Public License,
7# version 2, as published by the Free Software Foundation.
8#
9# This program is distributed in the hope it will be useful, but WITHOUT
10# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
12# more details.
13
14set -e
15
16usage()
17{
18        echo "Usage: perf-with-kcore <perf sub-command> <perf.data directory> [<sub-command options> [ -- <workload>]]" >&2
19        echo "       <perf sub-command> can be record, script, report or inject" >&2
20        echo "   or: perf-with-kcore fix_buildid_cache_permissions" >&2
21        exit 1
22}
23
24find_perf()
25{
26	if [ -n "$PERF" ] ; then
27		return
28	fi
29	PERF=`which perf || true`
30	if [ -z "$PERF" ] ; then
31		echo "Failed to find perf" >&2
32	        exit 1
33	fi
34	if [ ! -x "$PERF" ] ; then
35		echo "Failed to find perf" >&2
36	        exit 1
37	fi
38	echo "Using $PERF"
39	"$PERF" version
40}
41
42copy_kcore()
43{
44	echo "Copying kcore"
45
46	if [ $EUID -eq 0 ] ; then
47		SUDO=""
48	else
49		SUDO="sudo"
50	fi
51
52	rm -f perf.data.junk
53	("$PERF" record -o perf.data.junk "${PERF_OPTIONS[@]}" -- sleep 60) >/dev/null 2>/dev/null &
54	PERF_PID=$!
55
56	# Need to make sure that perf has started
57	sleep 1
58
59	KCORE=$(($SUDO "$PERF" buildid-cache -v -f -k /proc/kcore >/dev/null) 2>&1)
60	case "$KCORE" in
61	"kcore added to build-id cache directory "*)
62		KCORE_DIR=${KCORE#"kcore added to build-id cache directory "}
63	;;
64	*)
65		kill $PERF_PID
66		wait >/dev/null 2>/dev/null || true
67		rm perf.data.junk
68		echo "$KCORE"
69		echo "Failed to find kcore" >&2
70		exit 1
71	;;
72	esac
73
74	kill $PERF_PID
75	wait >/dev/null 2>/dev/null || true
76	rm perf.data.junk
77
78	$SUDO cp -a "$KCORE_DIR" "$(pwd)/$PERF_DATA_DIR"
79	$SUDO rm -f "$KCORE_DIR/kcore"
80	$SUDO rm -f "$KCORE_DIR/kallsyms"
81	$SUDO rm -f "$KCORE_DIR/modules"
82	$SUDO rmdir "$KCORE_DIR"
83
84	KCORE_DIR_BASENAME=$(basename "$KCORE_DIR")
85	KCORE_DIR="$(pwd)/$PERF_DATA_DIR/$KCORE_DIR_BASENAME"
86
87	$SUDO chown $UID "$KCORE_DIR"
88	$SUDO chown $UID "$KCORE_DIR/kcore"
89	$SUDO chown $UID "$KCORE_DIR/kallsyms"
90	$SUDO chown $UID "$KCORE_DIR/modules"
91
92	$SUDO chgrp $GROUPS "$KCORE_DIR"
93	$SUDO chgrp $GROUPS "$KCORE_DIR/kcore"
94	$SUDO chgrp $GROUPS "$KCORE_DIR/kallsyms"
95	$SUDO chgrp $GROUPS "$KCORE_DIR/modules"
96
97	ln -s "$KCORE_DIR_BASENAME" "$PERF_DATA_DIR/kcore_dir"
98}
99
100fix_buildid_cache_permissions()
101{
102	if [ $EUID -ne 0 ] ; then
103		echo "This script must be run as root via sudo " >&2
104		exit 1
105	fi
106
107	if [ -z "$SUDO_USER" ] ; then
108		echo "This script must be run via sudo" >&2
109		exit 1
110	fi
111
112	USER_HOME=$(bash <<< "echo ~$SUDO_USER")
113
114	if [ "$HOME" != "$USER_HOME" ] ; then
115		echo "Fix unnecessary because root has a home: $HOME" >&2
116		exit 1
117	fi
118
119	echo "Fixing buildid cache permissions"
120
121	find "$USER_HOME/.debug" -xdev -type d          ! -user "$SUDO_USER" -ls -exec chown    "$SUDO_USER" \{\} \;
122	find "$USER_HOME/.debug" -xdev -type f -links 1 ! -user "$SUDO_USER" -ls -exec chown    "$SUDO_USER" \{\} \;
123	find "$USER_HOME/.debug" -xdev -type l          ! -user "$SUDO_USER" -ls -exec chown -h "$SUDO_USER" \{\} \;
124
125	if [ -n "$SUDO_GID" ] ; then
126		find "$USER_HOME/.debug" -xdev -type d          ! -group "$SUDO_GID" -ls -exec chgrp    "$SUDO_GID" \{\} \;
127		find "$USER_HOME/.debug" -xdev -type f -links 1 ! -group "$SUDO_GID" -ls -exec chgrp    "$SUDO_GID" \{\} \;
128		find "$USER_HOME/.debug" -xdev -type l          ! -group "$SUDO_GID" -ls -exec chgrp -h "$SUDO_GID" \{\} \;
129	fi
130
131	echo "Done"
132}
133
134check_buildid_cache_permissions()
135{
136	if [ $EUID -eq 0 ] ; then
137		return
138	fi
139
140	PERMISSIONS_OK+=$(find "$HOME/.debug" -xdev -type d          ! -user "$USER" -print -quit)
141	PERMISSIONS_OK+=$(find "$HOME/.debug" -xdev -type f -links 1 ! -user "$USER" -print -quit)
142	PERMISSIONS_OK+=$(find "$HOME/.debug" -xdev -type l          ! -user "$USER" -print -quit)
143
144	PERMISSIONS_OK+=$(find "$HOME/.debug" -xdev -type d          ! -group "$GROUPS" -print -quit)
145	PERMISSIONS_OK+=$(find "$HOME/.debug" -xdev -type f -links 1 ! -group "$GROUPS" -print -quit)
146	PERMISSIONS_OK+=$(find "$HOME/.debug" -xdev -type l          ! -group "$GROUPS" -print -quit)
147
148	if [ -n "$PERMISSIONS_OK" ] ; then
149		echo "*** WARNING *** buildid cache permissions may need fixing" >&2
150	fi
151}
152
153record()
154{
155	echo "Recording"
156
157	if [ $EUID -ne 0 ] ; then
158
159		if [ "$(cat /proc/sys/kernel/kptr_restrict)" -ne 0 ] ; then
160			echo "*** WARNING *** /proc/sys/kernel/kptr_restrict prevents access to kernel addresses" >&2
161		fi
162
163		if echo "${PERF_OPTIONS[@]}" | grep -q ' -a \|^-a \| -a$\|^-a$\| --all-cpus \|^--all-cpus \| --all-cpus$\|^--all-cpus$' ; then
164			echo "*** WARNING *** system-wide tracing without root access will not be able to read all necessary information from /proc" >&2
165		fi
166
167		if echo "${PERF_OPTIONS[@]}" | grep -q 'intel_pt\|intel_bts\| -I\|^-I' ; then
168			if [ "$(cat /proc/sys/kernel/perf_event_paranoid)" -gt -1 ] ; then
169				echo "*** WARNING *** /proc/sys/kernel/perf_event_paranoid restricts buffer size and tracepoint (sched_switch) use" >&2
170			fi
171
172			if echo "${PERF_OPTIONS[@]}" | grep -q ' --per-thread \|^--per-thread \| --per-thread$\|^--per-thread$' ; then
173				true
174			elif echo "${PERF_OPTIONS[@]}" | grep -q ' -t \|^-t \| -t$\|^-t$' ; then
175				true
176			elif [ ! -r /sys/kernel/debug -o ! -x /sys/kernel/debug ] ; then
177				echo "*** WARNING *** /sys/kernel/debug permissions prevent tracepoint (sched_switch) use" >&2
178			fi
179		fi
180	fi
181
182	if [ -z "$1" ] ; then
183		echo "Workload is required for recording" >&2
184		usage
185	fi
186
187	if [ -e "$PERF_DATA_DIR" ] ; then
188		echo "'$PERF_DATA_DIR' exists" >&2
189		exit 1
190	fi
191
192	find_perf
193
194	mkdir "$PERF_DATA_DIR"
195
196	echo "$PERF record -o $PERF_DATA_DIR/perf.data ${PERF_OPTIONS[@]} -- $@"
197	"$PERF" record -o "$PERF_DATA_DIR/perf.data" "${PERF_OPTIONS[@]}" -- "$@" || true
198
199	if rmdir "$PERF_DATA_DIR" > /dev/null 2>/dev/null ; then
200		exit 1
201	fi
202
203	copy_kcore
204
205	echo "Done"
206}
207
208subcommand()
209{
210	find_perf
211	check_buildid_cache_permissions
212	echo "$PERF $PERF_SUB_COMMAND -i $PERF_DATA_DIR/perf.data --kallsyms=$PERF_DATA_DIR/kcore_dir/kallsyms $@"
213	"$PERF" $PERF_SUB_COMMAND -i "$PERF_DATA_DIR/perf.data" "--kallsyms=$PERF_DATA_DIR/kcore_dir/kallsyms" "$@"
214}
215
216if [ "$1" = "fix_buildid_cache_permissions" ] ; then
217	fix_buildid_cache_permissions
218	exit 0
219fi
220
221PERF_SUB_COMMAND=$1
222PERF_DATA_DIR=$2
223shift || true
224shift || true
225
226if [ -z "$PERF_SUB_COMMAND" ] ; then
227	usage
228fi
229
230if [ -z "$PERF_DATA_DIR" ] ; then
231	usage
232fi
233
234case "$PERF_SUB_COMMAND" in
235"record")
236	while [ "$1" != "--" ] ; do
237		PERF_OPTIONS+=("$1")
238		shift || break
239	done
240	if [ "$1" != "--" ] ; then
241		echo "Options and workload are required for recording" >&2
242		usage
243	fi
244	shift
245	record "$@"
246;;
247"script")
248	subcommand "$@"
249;;
250"report")
251	subcommand "$@"
252;;
253"inject")
254	subcommand "$@"
255;;
256*)
257	usage
258;;
259esac
260