From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932171AbaIQVZN (ORCPT ); Wed, 17 Sep 2014 17:25:13 -0400 Received: from mail.kernel.org ([198.145.19.201]:58044 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932080AbaIQVZJ (ORCPT ); Wed, 17 Sep 2014 17:25:09 -0400 From: Arnaldo Carvalho de Melo To: Ingo Molnar Cc: linux-kernel@vger.kernel.org, Adrian Hunter , David Ahern , Frederic Weisbecker , Jiri Olsa , Namhyung Kim , Paul Mackerras , Peter Zijlstra , Stephane Eranian , Arnaldo Carvalho de Melo Subject: [PATCH 08/20] perf tools: Add perf-with-kcore script Date: Wed, 17 Sep 2014 18:24:11 -0300 Message-Id: <1410989063-14207-9-git-send-email-acme@kernel.org> X-Mailer: git-send-email 1.9.3 In-Reply-To: <1410989063-14207-1-git-send-email-acme@kernel.org> References: <1410989063-14207-1-git-send-email-acme@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Adrian Hunter Decoding an Intel PT trace of the kernel requires an accurate kernel object image. This is provided by making a copy of kcore. However the copy needs to be made under the same conditions as the original recording, and then it needs to be associated with the perf.data file. The perf-with-kcore script does that. The script also checks the permissions on the buildid cache and can be used to fix them. That is needed for distributions where root does not have a home directory and consequently writes to the same buildid cache as the user, resulting in cached files that the user does not have access to. Example: $ ./perf-with-kcore Usage: perf-with-kcore [ [ -- ]] can be record, script, report or inject or: perf-with-kcore fix_buildid_cache_permissions $ ./perf-with-kcore record pt_uname -e intel_pt// -- uname Recording Using /home/ahunter/bin/perf perf version 3.15.rc3.g4549ba /home/ahunter/bin/perf record -o pt_uname/perf.data -e intel_pt// -- uname Linux [ perf record: Woken up 3 times to write data ] [ perf record: Captured and wrote 0.023 MB pt_uname/perf.data ] Copying kcore [sudo] password for ahunter: Done $ tools/perf/perf-with-kcore.sh script pt_uname | head Using /home/ahunter/bin/perf perf version 3.15.rc3.g4549ba /home/ahunter/bin/perf script -i pt_uname/perf.data --kallsyms=pt_uname/kcore_dir/kallsyms swapper 0 [002] 161533.969666: sched:sched_switch: swapper/2:0 [120] R ==> perf:11316 [120] :11315 11315 [003] 161533.969704: sched:sched_switch: perf:11315 [120] S ==> swapper/3:0 [120] :11316 11316 [002] 161533.969783: sched:sched_switch: perf:11316 [120] R ==> migration/2:33 [0] :33 33 [002] 161533.969791: sched:sched_switch: migration/2:33 [0] S ==> swapper/2:0 [120] swapper 0 [003] 161533.969792: sched:sched_switch: swapper/3:0 [120] R ==> perf:11316 [120] :11316 11316 [003] 161533.970062: branches: 0 [unknown] ([unknown]) => ffffffff810532fa native_write_msr_safe ([kernel.kallsyms]) :11316 11316 [003] 161533.970062: branches: ffffffff810532fd native_write_msr_safe ([kernel.kallsyms]) => ffffffff81035b31 pt_config_start ([kernel.kallsyms]) Signed-off-by: Adrian Hunter Cc: David Ahern Cc: Frederic Weisbecker Cc: Jiri Olsa Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/r/1406786474-9306-30-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/.gitignore | 1 + tools/perf/Makefile.perf | 5 +- tools/perf/perf-with-kcore.sh | 259 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 264 insertions(+), 1 deletion(-) create mode 100644 tools/perf/perf-with-kcore.sh diff --git a/tools/perf/.gitignore b/tools/perf/.gitignore index 782d86e961b9..717221e98450 100644 --- a/tools/perf/.gitignore +++ b/tools/perf/.gitignore @@ -15,6 +15,7 @@ perf.data perf.data.old output.svg perf-archive +perf-with-kcore tags TAGS cscope* diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf index 95e832b1bc3c..171f4e65601b 100644 --- a/tools/perf/Makefile.perf +++ b/tools/perf/Makefile.perf @@ -126,6 +126,7 @@ PYRF_OBJS = SCRIPT_SH = SCRIPT_SH += perf-archive.sh +SCRIPT_SH += perf-with-kcore.sh grep-libs = $(filter -l%,$(1)) strip-libs = $(filter-out -l%,$(1)) @@ -878,6 +879,8 @@ install-bin: all install-gtk $(INSTALL) -d -m 755 '$(DESTDIR_SQ)$(perfexec_instdir_SQ)' $(call QUIET_INSTALL, perf-archive) \ $(INSTALL) $(OUTPUT)perf-archive -t '$(DESTDIR_SQ)$(perfexec_instdir_SQ)' + $(call QUIET_INSTALL, perf-with-kcore) \ + $(INSTALL) $(OUTPUT)perf-with-kcore -t '$(DESTDIR_SQ)$(perfexec_instdir_SQ)' ifndef NO_LIBPERL $(call QUIET_INSTALL, perl-scripts) \ $(INSTALL) -d -m 755 '$(DESTDIR_SQ)$(perfexec_instdir_SQ)/scripts/perl/Perf-Trace-Util/lib/Perf/Trace'; \ @@ -923,7 +926,7 @@ config-clean: @$(MAKE) -C config/feature-checks clean >/dev/null clean: $(LIBTRACEEVENT)-clean $(LIBAPIKFS)-clean config-clean - $(call QUIET_CLEAN, core-objs) $(RM) $(LIB_OBJS) $(BUILTIN_OBJS) $(LIB_FILE) $(OUTPUT)perf-archive $(OUTPUT)perf.o $(LANG_BINDINGS) $(GTK_OBJS) + $(call QUIET_CLEAN, core-objs) $(RM) $(LIB_OBJS) $(BUILTIN_OBJS) $(LIB_FILE) $(OUTPUT)perf-archive $(OUTPUT)perf-with-kcore $(OUTPUT)perf.o $(LANG_BINDINGS) $(GTK_OBJS) $(call QUIET_CLEAN, core-progs) $(RM) $(ALL_PROGRAMS) perf $(call QUIET_CLEAN, core-gen) $(RM) *.spec *.pyc *.pyo */*.pyc */*.pyo $(OUTPUT)common-cmds.h TAGS tags cscope* $(OUTPUT)PERF-VERSION-FILE $(OUTPUT)PERF-CFLAGS $(OUTPUT)PERF-FEATURES $(OUTPUT)util/*-bison* $(OUTPUT)util/*-flex* $(QUIET_SUBDIR0)Documentation $(QUIET_SUBDIR1) clean diff --git a/tools/perf/perf-with-kcore.sh b/tools/perf/perf-with-kcore.sh new file mode 100644 index 000000000000..c7ff90a90e4e --- /dev/null +++ b/tools/perf/perf-with-kcore.sh @@ -0,0 +1,259 @@ +#!/bin/bash +# perf-with-kcore: use perf with a copy of kcore +# Copyright (c) 2014, Intel Corporation. +# +# This program is free software; you can redistribute it and/or modify it +# under the terms and conditions of the GNU General Public License, +# version 2, as published by the Free Software Foundation. +# +# This program is distributed in the hope it will be useful, but WITHOUT +# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or +# FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for +# more details. + +set -e + +usage() +{ + echo "Usage: perf-with-kcore [ [ -- ]]" >&2 + echo " can be record, script, report or inject" >&2 + echo " or: perf-with-kcore fix_buildid_cache_permissions" >&2 + exit 1 +} + +find_perf() +{ + if [ -n "$PERF" ] ; then + return + fi + PERF=`which perf || true` + if [ -z "$PERF" ] ; then + echo "Failed to find perf" >&2 + exit 1 + fi + if [ ! -x "$PERF" ] ; then + echo "Failed to find perf" >&2 + exit 1 + fi + echo "Using $PERF" + "$PERF" version +} + +copy_kcore() +{ + echo "Copying kcore" + + if [ $EUID -eq 0 ] ; then + SUDO="" + else + SUDO="sudo" + fi + + rm -f perf.data.junk + ("$PERF" record -o perf.data.junk $PERF_OPTIONS -- sleep 60) >/dev/null 2>/dev/null & + PERF_PID=$! + + # Need to make sure that perf has started + sleep 1 + + KCORE=$(($SUDO "$PERF" buildid-cache -v -f -k /proc/kcore >/dev/null) 2>&1) + case "$KCORE" in + "kcore added to build-id cache directory "*) + KCORE_DIR=${KCORE#"kcore added to build-id cache directory "} + ;; + *) + kill $PERF_PID + wait >/dev/null 2>/dev/null || true + rm perf.data.junk + echo "$KCORE" + echo "Failed to find kcore" >&2 + exit 1 + ;; + esac + + kill $PERF_PID + wait >/dev/null 2>/dev/null || true + rm perf.data.junk + + $SUDO cp -a "$KCORE_DIR" "$(pwd)/$PERF_DATA_DIR" + $SUDO rm -f "$KCORE_DIR/kcore" + $SUDO rm -f "$KCORE_DIR/kallsyms" + $SUDO rm -f "$KCORE_DIR/modules" + $SUDO rmdir "$KCORE_DIR" + + KCORE_DIR_BASENAME=$(basename "$KCORE_DIR") + KCORE_DIR="$(pwd)/$PERF_DATA_DIR/$KCORE_DIR_BASENAME" + + $SUDO chown $UID "$KCORE_DIR" + $SUDO chown $UID "$KCORE_DIR/kcore" + $SUDO chown $UID "$KCORE_DIR/kallsyms" + $SUDO chown $UID "$KCORE_DIR/modules" + + $SUDO chgrp $GROUPS "$KCORE_DIR" + $SUDO chgrp $GROUPS "$KCORE_DIR/kcore" + $SUDO chgrp $GROUPS "$KCORE_DIR/kallsyms" + $SUDO chgrp $GROUPS "$KCORE_DIR/modules" + + ln -s "$KCORE_DIR_BASENAME" "$PERF_DATA_DIR/kcore_dir" +} + +fix_buildid_cache_permissions() +{ + if [ $EUID -ne 0 ] ; then + echo "This script must be run as root via sudo " >&2 + exit 1 + fi + + if [ -z "$SUDO_USER" ] ; then + echo "This script must be run via sudo" >&2 + exit 1 + fi + + USER_HOME=$(bash <<< "echo ~$SUDO_USER") + + if [ "$HOME" != "$USER_HOME" ] ; then + echo "Fix unnecessary because root has a home: $HOME" >&2 + exit 1 + fi + + echo "Fixing buildid cache permissions" + + find "$USER_HOME/.debug" -xdev -type d ! -user "$SUDO_USER" -ls -exec chown "$SUDO_USER" \{\} \; + find "$USER_HOME/.debug" -xdev -type f -links 1 ! -user "$SUDO_USER" -ls -exec chown "$SUDO_USER" \{\} \; + find "$USER_HOME/.debug" -xdev -type l ! -user "$SUDO_USER" -ls -exec chown -h "$SUDO_USER" \{\} \; + + if [ -n "$SUDO_GID" ] ; then + find "$USER_HOME/.debug" -xdev -type d ! -group "$SUDO_GID" -ls -exec chgrp "$SUDO_GID" \{\} \; + find "$USER_HOME/.debug" -xdev -type f -links 1 ! -group "$SUDO_GID" -ls -exec chgrp "$SUDO_GID" \{\} \; + find "$USER_HOME/.debug" -xdev -type l ! -group "$SUDO_GID" -ls -exec chgrp -h "$SUDO_GID" \{\} \; + fi + + echo "Done" +} + +check_buildid_cache_permissions() +{ + if [ $EUID -eq 0 ] ; then + return + fi + + PERMISSIONS_OK+=$(find "$HOME/.debug" -xdev -type d ! -user "$USER" -print -quit) + PERMISSIONS_OK+=$(find "$HOME/.debug" -xdev -type f -links 1 ! -user "$USER" -print -quit) + PERMISSIONS_OK+=$(find "$HOME/.debug" -xdev -type l ! -user "$USER" -print -quit) + + PERMISSIONS_OK+=$(find "$HOME/.debug" -xdev -type d ! -group "$GROUPS" -print -quit) + PERMISSIONS_OK+=$(find "$HOME/.debug" -xdev -type f -links 1 ! -group "$GROUPS" -print -quit) + PERMISSIONS_OK+=$(find "$HOME/.debug" -xdev -type l ! -group "$GROUPS" -print -quit) + + if [ -n "$PERMISSIONS_OK" ] ; then + echo "*** WARNING *** buildid cache permissions may need fixing" >&2 + fi +} + +record() +{ + echo "Recording" + + if [ $EUID -ne 0 ] ; then + + if [ "$(cat /proc/sys/kernel/kptr_restrict)" -ne 0 ] ; then + echo "*** WARNING *** /proc/sys/kernel/kptr_restrict prevents access to kernel addresses" >&2 + fi + + if echo "$PERF_OPTIONS" | grep -q ' -a \|^-a \| -a$\|^-a$\| --all-cpus \|^--all-cpus \| --all-cpus$\|^--all-cpus$' ; then + echo "*** WARNING *** system-wide tracing without root access will not be able to read all necessary information from /proc" >&2 + fi + + if echo "$PERF_OPTIONS" | grep -q 'intel_pt\|intel_bts\| -I\|^-I' ; then + if [ "$(cat /proc/sys/kernel/perf_event_paranoid)" -gt -1 ] ; then + echo "*** WARNING *** /proc/sys/kernel/perf_event_paranoid restricts buffer size and tracepoint (sched_switch) use" >&2 + fi + + if echo "$PERF_OPTIONS" | grep -q ' --per-thread \|^--per-thread \| --per-thread$\|^--per-thread$' ; then + true + elif echo "$PERF_OPTIONS" | grep -q ' -t \|^-t \| -t$\|^-t$' ; then + true + elif [ ! -r /sys/kernel/debug -o ! -x /sys/kernel/debug ] ; then + echo "*** WARNING *** /sys/kernel/debug permissions prevent tracepoint (sched_switch) use" >&2 + fi + fi + fi + + if [ -z "$1" ] ; then + echo "Workload is required for recording" >&2 + usage + fi + + if [ -e "$PERF_DATA_DIR" ] ; then + echo "'$PERF_DATA_DIR' exists" >&2 + exit 1 + fi + + find_perf + + mkdir "$PERF_DATA_DIR" + + echo "$PERF record -o $PERF_DATA_DIR/perf.data $PERF_OPTIONS -- $*" + "$PERF" record -o "$PERF_DATA_DIR/perf.data" $PERF_OPTIONS -- $* || true + + if rmdir "$PERF_DATA_DIR" > /dev/null 2>/dev/null ; then + exit 1 + fi + + copy_kcore + + echo "Done" +} + +subcommand() +{ + find_perf + check_buildid_cache_permissions + echo "$PERF $PERF_SUB_COMMAND -i $PERF_DATA_DIR/perf.data --kallsyms=$PERF_DATA_DIR/kcore_dir/kallsyms $*" + "$PERF" $PERF_SUB_COMMAND -i "$PERF_DATA_DIR/perf.data" "--kallsyms=$PERF_DATA_DIR/kcore_dir/kallsyms" $* +} + +if [ "$1" = "fix_buildid_cache_permissions" ] ; then + fix_buildid_cache_permissions + exit 0 +fi + +PERF_SUB_COMMAND=$1 +PERF_DATA_DIR=$2 +shift || true +shift || true + +if [ -z "$PERF_SUB_COMMAND" ] ; then + usage +fi + +if [ -z "$PERF_DATA_DIR" ] ; then + usage +fi + +case "$PERF_SUB_COMMAND" in +"record") + while [ "$1" != "--" ] ; do + PERF_OPTIONS+="$1 " + shift || break + done + if [ "$1" != "--" ] ; then + echo "Options and workload are required for recording" >&2 + usage + fi + shift + record $* +;; +"script") + subcommand $* +;; +"report") + subcommand $* +;; +"inject") + subcommand $* +;; +*) + usage +;; +esac -- 1.9.3