From patchwork Thu May 28 13:48:46 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yannick Cote X-Patchwork-Id: 208461 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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED autolearn=ham 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 0CC09C433DF for ; Thu, 28 May 2020 13:49:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E0741207D3 for ; Thu, 28 May 2020 13:49:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="HtT/Njkv" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390550AbgE1NtC (ORCPT ); Thu, 28 May 2020 09:49:02 -0400 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:53503 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2390514AbgE1NtB (ORCPT ); Thu, 28 May 2020 09:49:01 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1590673739; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=TJL20W3ir/b9MVshm2OPM91U5HXtTb+5zv6fUX0lrTk=; b=HtT/Njkv8+nbSIQvIVK9aSqxJsCJUcUcBR7szaTro33Y//AGxtP8uj057u+PJSh8d61C2z C2Kcj7vDAAHRVF/YkLw1nz09DhvcpZczwrJLvd2xC6Mx0CmSR/PeJnCPZh/pXXw02KREtI uYPjxKX6jF+UkIxYJjNevGT4LZGKyNo= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-39-bU2HXs-YPTyO22tTMBRIRg-1; Thu, 28 May 2020 09:48:57 -0400 X-MC-Unique: bU2HXs-YPTyO22tTMBRIRg-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 628CD107ACCA; Thu, 28 May 2020 13:48:56 +0000 (UTC) Received: from dm.redhat.com (ovpn-114-140.rdu2.redhat.com [10.10.114.140]) by smtp.corp.redhat.com (Postfix) with ESMTP id D20B9797EB; Thu, 28 May 2020 13:48:55 +0000 (UTC) From: Yannick Cote To: live-patching@vger.kernel.org Cc: linux-kselftest@vger.kernel.org, joe.lawrence@redhat.com Subject: [PATCH 1/4] selftests/livepatch: rework test-klp-callbacks to use completion variables Date: Thu, 28 May 2020 09:48:46 -0400 Message-Id: <20200528134849.7890-2-ycote@redhat.com> In-Reply-To: <20200528134849.7890-1-ycote@redhat.com> References: <20200528134849.7890-1-ycote@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Sender: linux-kselftest-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org From: Joe Lawrence The test-klp-callbacks script includes a few tests which rely on kernel task timings that may not always execute as expected under system load. These will generate out of sequence kernel log messages that result in test failure. Instead of using sleep timing windows to orchestrate the test, rework the test_klp_callbacks_busy module to use completion variables. Signed-off-by: Joe Lawrence Signed-off-by: Yannick Cote --- lib/livepatch/test_klp_callbacks_busy.c | 42 +++++++++++++++---- .../selftests/livepatch/test-callbacks.sh | 29 +++++++------ 2 files changed, 47 insertions(+), 24 deletions(-) diff --git a/lib/livepatch/test_klp_callbacks_busy.c b/lib/livepatch/test_klp_callbacks_busy.c index 40beddf8a0e2..c3df12f47e5e 100644 --- a/lib/livepatch/test_klp_callbacks_busy.c +++ b/lib/livepatch/test_klp_callbacks_busy.c @@ -5,34 +5,58 @@ #include #include +#include #include #include -static int sleep_secs; -module_param(sleep_secs, int, 0644); -MODULE_PARM_DESC(sleep_secs, "sleep_secs (default=0)"); +/* load/run-time control from sysfs writer */ +static bool block_transition; +module_param(block_transition, bool, 0644); +MODULE_PARM_DESC(block_transition, "block_transition (default=false)"); static void busymod_work_func(struct work_struct *work); -static DECLARE_DELAYED_WORK(work, busymod_work_func); +static DECLARE_WORK(work, busymod_work_func); +static DECLARE_COMPLETION(busymod_work_complete); static void busymod_work_func(struct work_struct *work) { - pr_info("%s, sleeping %d seconds ...\n", __func__, sleep_secs); - msleep(sleep_secs * 1000); + bool early_complete = block_transition; + + pr_info("%s enter\n", __func__); + + /* + * When blocking the livepatch transition, set completion flag + * early so subsequent test commands see the transition. + */ + if (early_complete) + complete(&busymod_work_complete); + + while (block_transition) + msleep(1000); + pr_info("%s exit\n", __func__); + + /* + * In non-blocking case, wait until we're done to complete to + * ensure kernel log ordering + */ + if (!early_complete) + complete(&busymod_work_complete); } static int test_klp_callbacks_busy_init(void) { pr_info("%s\n", __func__); - schedule_delayed_work(&work, - msecs_to_jiffies(1000 * 0)); + schedule_work(&work); + wait_for_completion(&busymod_work_complete); + return 0; } static void test_klp_callbacks_busy_exit(void) { - cancel_delayed_work_sync(&work); + block_transition = false; + cancel_work_sync(&work); pr_info("%s\n", __func__); } diff --git a/tools/testing/selftests/livepatch/test-callbacks.sh b/tools/testing/selftests/livepatch/test-callbacks.sh index a35289b13c9c..32b57ba07f4f 100755 --- a/tools/testing/selftests/livepatch/test-callbacks.sh +++ b/tools/testing/selftests/livepatch/test-callbacks.sh @@ -356,9 +356,7 @@ livepatch: '$MOD_LIVEPATCH': unpatching complete echo -n "TEST: multiple target modules ... " dmesg -C -load_mod $MOD_TARGET_BUSY sleep_secs=0 -# give $MOD_TARGET_BUSY::busymod_work_func() a chance to run -sleep 5 +load_mod $MOD_TARGET_BUSY block_transition=N load_lp $MOD_LIVEPATCH load_mod $MOD_TARGET unload_mod $MOD_TARGET @@ -366,9 +364,9 @@ disable_lp $MOD_LIVEPATCH unload_lp $MOD_LIVEPATCH unload_mod $MOD_TARGET_BUSY -check_result "% modprobe $MOD_TARGET_BUSY sleep_secs=0 +check_result "% modprobe $MOD_TARGET_BUSY block_transition=N $MOD_TARGET_BUSY: ${MOD_TARGET_BUSY}_init -$MOD_TARGET_BUSY: busymod_work_func, sleeping 0 seconds ... +$MOD_TARGET_BUSY: busymod_work_func enter $MOD_TARGET_BUSY: busymod_work_func exit % modprobe $MOD_LIVEPATCH livepatch: enabling patch '$MOD_LIVEPATCH' @@ -404,11 +402,10 @@ livepatch: '$MOD_LIVEPATCH': unpatching complete $MOD_TARGET_BUSY: ${MOD_TARGET_BUSY}_exit" - # TEST: busy target module # # A similar test as the previous one, but force the "busy" kernel module -# to do longer work. +# to block the livepatch transition. # # The livepatching core will refuse to patch a task that is currently # executing a to-be-patched function -- the consistency model stalls the @@ -417,8 +414,7 @@ $MOD_TARGET_BUSY: ${MOD_TARGET_BUSY}_exit" # function for a long time. Meanwhile, load and unload other target # kernel modules while the livepatch transition is in progress. # -# - Load the "busy" kernel module, this time make it do 10 seconds worth -# of work. +# - Load the "busy" kernel module, this time make its work function loop # # - Meanwhile, the livepatch is loaded. Notice that the patch # transition does not complete as the targeted "busy" module is @@ -438,20 +434,23 @@ $MOD_TARGET_BUSY: ${MOD_TARGET_BUSY}_exit" echo -n "TEST: busy target module ... " dmesg -C -load_mod $MOD_TARGET_BUSY sleep_secs=10 +load_mod $MOD_TARGET_BUSY block_transition=Y load_lp_nowait $MOD_LIVEPATCH -# Don't wait for transition, load $MOD_TARGET while the transition -# is still stalled in $MOD_TARGET_BUSY::busymod_work_func() -sleep 5 + +# Wait until the livepatch reports in-transition state, i.e. that it's +# stalled on $MOD_TARGET_BUSY::busymod_work_func() +loop_until 'grep -q '^1$' /sys/kernel/livepatch/$MOD_LIVEPATCH/transition' || + die "failed to stall transition" + load_mod $MOD_TARGET unload_mod $MOD_TARGET disable_lp $MOD_LIVEPATCH unload_lp $MOD_LIVEPATCH unload_mod $MOD_TARGET_BUSY -check_result "% modprobe $MOD_TARGET_BUSY sleep_secs=10 +check_result "% modprobe $MOD_TARGET_BUSY block_transition=Y $MOD_TARGET_BUSY: ${MOD_TARGET_BUSY}_init -$MOD_TARGET_BUSY: busymod_work_func, sleeping 10 seconds ... +$MOD_TARGET_BUSY: busymod_work_func enter % modprobe $MOD_LIVEPATCH livepatch: enabling patch '$MOD_LIVEPATCH' livepatch: '$MOD_LIVEPATCH': initializing patching transition