From patchwork Wed Feb 3 23:41:16 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniel Latypov X-Patchwork-Id: 375647 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=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT,USER_IN_DEF_DKIM_WL 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 A3925C433E9 for ; Wed, 3 Feb 2021 23:43:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 76A7E64F51 for ; Wed, 3 Feb 2021 23:43:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233362AbhBCXnC (ORCPT ); Wed, 3 Feb 2021 18:43:02 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33486 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234050AbhBCXmq (ORCPT ); Wed, 3 Feb 2021 18:42:46 -0500 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5657EC061793 for ; Wed, 3 Feb 2021 15:41:29 -0800 (PST) Received: by mail-yb1-xb49.google.com with SMTP id v7so1457801ybl.15 for ; Wed, 03 Feb 2021 15:41:29 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=sender:date:in-reply-to:message-id:mime-version:references:subject :from:to:cc; bh=/SVhbM2uQkfhx0nM8S6aEm/0ZcJ7ciNGwmg4LfVvDlo=; b=Q+TS3qW6SM6wIum0mxOGE5YURZnsMYYXVSeHKas03nAKV+6CXav4beYt/9wPKkYXU6 W7jrNlSwqIxTLQK14x0h5aIOha4ZURMIfOSQfORcGG8lxtMT1NLiKJWFCSyrtFKDBLI+ OBD/YYnJKDCm/OXCc+d2le2RtKUf126s9WMiQHkHe0oSGLf1PwxnmLbyapGx3yC7AIzA 3iguXBVmPPf1f80hNqk25+6EINJkRiJ6JwMYJpTlrWAxulcRsYIZhjlTu5nPPWpYSS7k /uHRc7Xbi186oOVVHyj/z4my/C0QM++n7iTgbkqPXswDLlj70yQViF+QgstB2XfXEsQd 327g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=/SVhbM2uQkfhx0nM8S6aEm/0ZcJ7ciNGwmg4LfVvDlo=; b=A/1vmU/LEnUdKQtUH1JzSbtBfIJWje8soaod+uqZBKiIjq8x2zLRByCy4Psf5zdFx4 xfQdv3HcXmt2og9vRaVq2qsnLfPWsGw5N+TWI9G1cn1Yleb6pE9SKuE96lv5/RvTFcbt X9zvuVN09CVQMtEiBXjd0DHjI4btvIjzGq/p592RRoqNXJc1Wieq8eRHwmZ3jW7jLbWd cqb6sLEEBI6DOtPG2W3owEhSJ20JGfwjtpQGCK7BE0WNWpn75Z7TannVcLkhvppRrUju huLYDLvdlHYFlbO3FsiRPYZrShBlklp12yJ034y+07aaLMcGa0uS20hTpRpddkn/wtLm P4UA== X-Gm-Message-State: AOAM531RaxT2rA8sCvlt26b9FNhJ/BtKWElVJn2NCub70z8YHpxkyGtC XMbgCeR050VdgCiCw/ZGMojGFg9YWCSHNQ== X-Google-Smtp-Source: ABdhPJxW1mSlBMiPe8VFlR0C0NhwCMngW1NOxzWO+d2kKzqhcyVSzN7MogWuLZ/h8WcbhdA1GJCFqxYTIbPQ1g== Sender: "dlatypov via sendgmr" X-Received: from dlatypov.svl.corp.google.com ([2620:15c:2cd:202:bd7a:7717:5b5b:de27]) (user=dlatypov job=sendgmr) by 2002:a05:6902:706:: with SMTP id k6mr8182212ybt.52.1612395688574; Wed, 03 Feb 2021 15:41:28 -0800 (PST) Date: Wed, 3 Feb 2021 15:41:16 -0800 In-Reply-To: <20210203234116.839819-1-dlatypov@google.com> Message-Id: <20210203234116.839819-4-dlatypov@google.com> Mime-Version: 1.0 References: <20210203234116.839819-1-dlatypov@google.com> X-Mailer: git-send-email 2.30.0.365.g02bc693789-goog Subject: [PATCH 3/3] kunit: tool: fix unintentional statefulness in run_kernel() From: Daniel Latypov To: brendanhiggins@google.com, davidgow@google.com Cc: linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, skhan@linuxfoundation.org, Daniel Latypov Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org This is a bug that has been present since the first version of this code. Using [] as a default parameter is dangerous, since it's mutable. Example using the REPL: >>> def bad(param = []): ... param.append(len(param)) ... print(param) ... >>> bad() [0] >>> bad() [0, 1] This wasn't a concern in the past since it would just keep appending the same values to it. E.g. before, `args` would just grow in size like: [mem=1G', 'console=tty'] [mem=1G', 'console=tty', mem=1G', 'console=tty'] But with now filter_glob, this is more dangerous, e.g. run_kernel(filter_glob='my-test*') # default modified here run_kernel() # filter_glob still applies here! That earlier `filter_glob` will affect all subsequent calls that don't specify `args`. Note: currently the kunit tool only calls run_kernel() at most once, so it's not possible to trigger any negative side-effects right now. Fixes: 6ebf5866f2e8 ("kunit: tool: add Python wrappers for running KUnit tests") Signed-off-by: Daniel Latypov --- tools/testing/kunit/kunit_kernel.py | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/tools/testing/kunit/kunit_kernel.py b/tools/testing/kunit/kunit_kernel.py index 71b1942f5ccd..6dd3cf6e8efa 100644 --- a/tools/testing/kunit/kunit_kernel.py +++ b/tools/testing/kunit/kunit_kernel.py @@ -199,7 +199,9 @@ class LinuxSourceTree(object): return False return self.validate_config(build_dir) - def run_kernel(self, args=[], build_dir='', filter_glob='', timeout=None) -> Iterator[str]: + def run_kernel(self, args=None, build_dir='', filter_glob='', timeout=None) -> Iterator[str]: + if not args: + args = [] args.extend(['mem=1G', 'console=tty']) if filter_glob: args.append('kunit.filter_glob='+filter_glob)