From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BA3F9ECE588 for ; Tue, 15 Oct 2019 14:58:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8A6E22054F for ; Tue, 15 Oct 2019 14:58:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733146AbfJOO6F (ORCPT ); Tue, 15 Oct 2019 10:58:05 -0400 Received: from mx1.redhat.com ([209.132.183.28]:43786 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726523AbfJOO6E (ORCPT ); Tue, 15 Oct 2019 10:58:04 -0400 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 2D3E03175295; Tue, 15 Oct 2019 14:58:04 +0000 (UTC) Received: from redhat.com (dhcp-17-119.bos.redhat.com [10.18.17.119]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 23E7510027C5; Tue, 15 Oct 2019 14:58:03 +0000 (UTC) Date: Tue, 15 Oct 2019 10:58:01 -0400 From: Joe Lawrence To: Miroslav Benes Cc: rostedt@goodmis.org, mingo@redhat.com, jpoimboe@redhat.com, jikos@kernel.org, pmladek@suse.com, linux-kernel@vger.kernel.org, live-patching@vger.kernel.org Subject: Re: [PATCH v2] ftrace: Introduce PERMANENT ftrace_ops flag Message-ID: <20191015145801.GA9922@redhat.com> References: <20191014105923.29607-1-mbenes@suse.cz> <20191014223100.GA16608@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.12.1 (2019-06-15) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.49]); Tue, 15 Oct 2019 14:58:04 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 15, 2019 at 01:23:10PM +0200, Miroslav Benes wrote: > > Hi Miroslav, > > > > Maybe we should add a test to verify this new behavior? See sample > > version below (lightly tested). We can add to this one, or patch > > seperately if you prefer. > > Thanks a lot, Joe. It looks nice. I'll include it in v3. One question > below. > > [ ... snip ... ] > > Shouldn't we call push_ftrace_enabled() somewhere at the beginning of the > test script? set_dynamic_debug() calls its push_dynamic_debug() directly, > but set_ftrace_enabled() is different, because it is called more than once > in the script. > > One could argue that ftrace_enabled has to be true at the beginning of > testing anyway, but I think it would be cleaner. Btw, we should probably > guarantee that ftrace_enabled is true when livepatch selftests are > invoked. > Here's a new version that combines the ftrace_enabled configuration with the debugfs stuff (so its only pushed/pop once per test) and updates all the tests accordingly. Feel free to any tweaks or flourishes when adding to v3. Thanks, -- Joe -->8-- -->8-- -->8-- -->8-- -->8-- -->8-- -->8-- -->8-- -->8-- -->8-- >From a22ca55b3f429b7c9ceed6be87a571f77520994c Mon Sep 17 00:00:00 2001 From: Joe Lawrence Date: Tue, 15 Oct 2019 10:33:18 -0400 Subject: [PATCH] selftests/livepatch: test interaction with ftrace_enabled Since livepatching depends upon ftrace handlers to implement "patched" code functionality, verify that the ftrace_enabled sysctl value interacts with livepatch registration as expected. At the same time, ensure that ftrace_enabled is set and part of the test environment configuration that is saved and restored when running the selftests. Signed-off-by: Joe Lawrence --- tools/testing/selftests/livepatch/Makefile | 3 +- .../testing/selftests/livepatch/functions.sh | 34 +++++++--- .../selftests/livepatch/test-callbacks.sh | 2 +- .../selftests/livepatch/test-ftrace.sh | 65 +++++++++++++++++++ .../selftests/livepatch/test-livepatch.sh | 2 +- .../selftests/livepatch/test-shadow-vars.sh | 2 +- 6 files changed, 95 insertions(+), 13 deletions(-) create mode 100755 tools/testing/selftests/livepatch/test-ftrace.sh diff --git a/tools/testing/selftests/livepatch/Makefile b/tools/testing/selftests/livepatch/Makefile index fd405402c3ff..1886d9d94b88 100644 --- a/tools/testing/selftests/livepatch/Makefile +++ b/tools/testing/selftests/livepatch/Makefile @@ -4,6 +4,7 @@ TEST_PROGS_EXTENDED := functions.sh TEST_PROGS := \ test-livepatch.sh \ test-callbacks.sh \ - test-shadow-vars.sh + test-shadow-vars.sh \ + test-ftrace.sh include ../lib.mk diff --git a/tools/testing/selftests/livepatch/functions.sh b/tools/testing/selftests/livepatch/functions.sh index 79b0affd21fb..31eb09e38729 100644 --- a/tools/testing/selftests/livepatch/functions.sh +++ b/tools/testing/selftests/livepatch/functions.sh @@ -29,29 +29,45 @@ function die() { exit 1 } -function push_dynamic_debug() { - DYNAMIC_DEBUG=$(grep '^kernel/livepatch' /sys/kernel/debug/dynamic_debug/control | \ - awk -F'[: ]' '{print "file " $1 " line " $2 " " $4}') +function push_config() { + DYNAMIC_DEBUG=$(grep '^kernel/livepatch' /sys/kernel/debug/dynamic_debug/control | \ + awk -F'[: ]' '{print "file " $1 " line " $2 " " $4}') + FTRACE_ENABLED=$(sysctl --values kernel.ftrace_enabled) } -function pop_dynamic_debug() { +function pop_config() { if [[ -n "$DYNAMIC_DEBUG" ]]; then echo -n "$DYNAMIC_DEBUG" > /sys/kernel/debug/dynamic_debug/control fi + if [[ -n "$FTRACE_ENABLED" ]]; then + sysctl kernel.ftrace_enabled="$FTRACE_ENABLED" &> /dev/null + fi } -# set_dynamic_debug() - save the current dynamic debug config and tweak -# it for the self-tests. Set a script exit trap -# that restores the original config. function set_dynamic_debug() { - push_dynamic_debug - trap pop_dynamic_debug EXIT INT TERM HUP cat <<-EOF > /sys/kernel/debug/dynamic_debug/control file kernel/livepatch/* +p func klp_try_switch_task -p EOF } +function set_ftrace_enabled() { + local sysctl="$1" + result=$(sysctl kernel.ftrace_enabled="$1" 2>&1 | paste --serial --delimiters=' ') + echo "livepatch: $result" > /dev/kmsg +} + +# setup_config - save the current config and set a script exit trap that +# restores the original config. Setup the dynamic debug +# for verbose livepatching output and turn on +# the ftrace_enabled sysctl. +function setup_config() { + push_config + set_dynamic_debug + set_ftrace_enabled 1 + trap pop_config EXIT INT TERM HUP +} + # loop_until(cmd) - loop a command until it is successful or $MAX_RETRIES, # sleep $RETRY_INTERVAL between attempts # cmd - command and its arguments to run diff --git a/tools/testing/selftests/livepatch/test-callbacks.sh b/tools/testing/selftests/livepatch/test-callbacks.sh index e97a9dcb73c7..a35289b13c9c 100755 --- a/tools/testing/selftests/livepatch/test-callbacks.sh +++ b/tools/testing/selftests/livepatch/test-callbacks.sh @@ -9,7 +9,7 @@ MOD_LIVEPATCH2=test_klp_callbacks_demo2 MOD_TARGET=test_klp_callbacks_mod MOD_TARGET_BUSY=test_klp_callbacks_busy -set_dynamic_debug +setup_config # TEST: target module before livepatch diff --git a/tools/testing/selftests/livepatch/test-ftrace.sh b/tools/testing/selftests/livepatch/test-ftrace.sh new file mode 100755 index 000000000000..e2a76887f40a --- /dev/null +++ b/tools/testing/selftests/livepatch/test-ftrace.sh @@ -0,0 +1,65 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +# Copyright (C) 2019 Joe Lawrence + +. $(dirname $0)/functions.sh + +MOD_LIVEPATCH=test_klp_livepatch + +setup_config + + +# TEST: livepatch interaction with ftrace_enabled sysctl +# - turn ftrace_enabled OFF and verify livepatches can't load +# - turn ftrace_enabled ON and verify livepatch can load +# - verify that ftrace_enabled can't be turned OFF while a livepatch is loaded + +echo -n "TEST: livepatch interaction with ftrace_enabled sysctl ... " +dmesg -C + +set_ftrace_enabled 0 +load_failing_mod $MOD_LIVEPATCH + +set_ftrace_enabled 1 +load_lp $MOD_LIVEPATCH +if [[ "$(cat /proc/cmdline)" != "$MOD_LIVEPATCH: this has been live patched" ]] ; then + echo -e "FAIL\n\n" + die "livepatch kselftest(s) failed" +fi + +set_ftrace_enabled 0 +if [[ "$(cat /proc/cmdline)" != "$MOD_LIVEPATCH: this has been live patched" ]] ; then + echo -e "FAIL\n\n" + die "livepatch kselftest(s) failed" +fi +disable_lp $MOD_LIVEPATCH +unload_lp $MOD_LIVEPATCH + +check_result "livepatch: kernel.ftrace_enabled = 0 +% modprobe $MOD_LIVEPATCH +livepatch: enabling patch '$MOD_LIVEPATCH' +livepatch: '$MOD_LIVEPATCH': initializing patching transition +livepatch: failed to register ftrace handler for function 'cmdline_proc_show' (-16) +livepatch: failed to patch object 'vmlinux' +livepatch: failed to enable patch '$MOD_LIVEPATCH' +livepatch: '$MOD_LIVEPATCH': canceling patching transition, going to unpatch +livepatch: '$MOD_LIVEPATCH': completing unpatching transition +livepatch: '$MOD_LIVEPATCH': unpatching complete +modprobe: ERROR: could not insert '$MOD_LIVEPATCH': Device or resource busy +livepatch: kernel.ftrace_enabled = 1 +% modprobe $MOD_LIVEPATCH +livepatch: enabling patch '$MOD_LIVEPATCH' +livepatch: '$MOD_LIVEPATCH': initializing patching transition +livepatch: '$MOD_LIVEPATCH': starting patching transition +livepatch: '$MOD_LIVEPATCH': completing patching transition +livepatch: '$MOD_LIVEPATCH': patching complete +livepatch: sysctl: setting key \"kernel.ftrace_enabled\": Device or resource busy kernel.ftrace_enabled = 0 +% echo 0 > /sys/kernel/livepatch/$MOD_LIVEPATCH/enabled +livepatch: '$MOD_LIVEPATCH': initializing unpatching transition +livepatch: '$MOD_LIVEPATCH': starting unpatching transition +livepatch: '$MOD_LIVEPATCH': completing unpatching transition +livepatch: '$MOD_LIVEPATCH': unpatching complete +% rmmod $MOD_LIVEPATCH" + + +exit 0 diff --git a/tools/testing/selftests/livepatch/test-livepatch.sh b/tools/testing/selftests/livepatch/test-livepatch.sh index f05268aea859..493e3df415a1 100755 --- a/tools/testing/selftests/livepatch/test-livepatch.sh +++ b/tools/testing/selftests/livepatch/test-livepatch.sh @@ -7,7 +7,7 @@ MOD_LIVEPATCH=test_klp_livepatch MOD_REPLACE=test_klp_atomic_replace -set_dynamic_debug +setup_config # TEST: basic function patching diff --git a/tools/testing/selftests/livepatch/test-shadow-vars.sh b/tools/testing/selftests/livepatch/test-shadow-vars.sh index 04a37831e204..1aae73299114 100755 --- a/tools/testing/selftests/livepatch/test-shadow-vars.sh +++ b/tools/testing/selftests/livepatch/test-shadow-vars.sh @@ -6,7 +6,7 @@ MOD_TEST=test_klp_shadow_vars -set_dynamic_debug +setup_config # TEST: basic shadow variable API -- 2.21.0