From patchwork Thu Feb 4 17:30:45 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniel Latypov X-Patchwork-Id: 377279 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=-26.2 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=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 D1648C433E0 for ; Thu, 4 Feb 2021 17:41:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9504264E4E for ; Thu, 4 Feb 2021 17:41:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238495AbhBDRlQ (ORCPT ); Thu, 4 Feb 2021 12:41:16 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37106 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238598AbhBDRcv (ORCPT ); Thu, 4 Feb 2021 12:32:51 -0500 Received: from mail-qt1-x849.google.com (mail-qt1-x849.google.com [IPv6:2607:f8b0:4864:20::849]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8056DC061224 for ; Thu, 4 Feb 2021 09:31:02 -0800 (PST) Received: by mail-qt1-x849.google.com with SMTP id k90so3146179qte.4 for ; Thu, 04 Feb 2021 09:31:02 -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=Thvd174F9a+GsewOT+nlcPKlXmhil/8YBJC6kx0cQirSj3kOEGPIWE8+idsYw/Jt/D 4+BPW1mdGFi0Rkh5ZAT/GedqQOr8xgFt+rmK97J+dp+Ochcs4qZnfIIE1BJB5LPaFcYp JfwwAlORU8NGAtvPlQAJhvBr0yfxL6C5EA0+gFdlv6DPwNhxYkDiwPn14I0E+SAX+CPH WX/TaymNi6HCVBh/ogLhTWVwiIFPrq4HTnAo9nEPSmB3O2Zmf/E1M8UIRSOLYarJAEEo 7kq6GemeNytdIJxjXaMhUk5RYqcoJhRBPQav2eRcI+KM+xDVwl1nJO1V74nDIQw0ooeK N5XQ== 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=rexql2cPoL5TnqEpt4RuwBcAzisGwDIFD83CkMHjx2hDi90892KUVqkCukAeToCrcB mBHVJu2QYQ4zagUPyOnf3EGZ92z0HzS7Ch8aoc96HQRXkHXwAmvWsFmtohugnrrp3NJ/ 82KRJPfBha6749iDm7/eyFW5YyrieY2XS5dxiouqSEuvLgAwCq+IAGBoQSzWrVQH1zs/ 7UmcZXhr/LRbBsTzCKq3VBQ3bohyrqApnfuOM6ogEJtHa30UodDCIF1uk2ZvhkU+o8yl Z+B04Qv5qpxLmu2oypOWHNObLFmTQeRKZbfzSD6yoQzEcwFnrjlXUZT+iAjR9keNkAJS V8jw== X-Gm-Message-State: AOAM530w98B3Yg3uhNv4fRqXpgxc/GCPuZ/+rEeyxhchhvxUKTp6uHU2 JM5QmBVCqLQOYXnq9cFiXP+5hqyulWhJbA== X-Google-Smtp-Source: ABdhPJxeiBQhDE8ipCm5Yam3J5DXGKIM5RehWcKf6aRy7SPNSKUDJBO2mDGDRSy/Rz3KEXmTwZZRGuB2CbHeqw== 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:a0c:ee89:: with SMTP id u9mr514981qvr.40.1612459861632; Thu, 04 Feb 2021 09:31:01 -0800 (PST) Date: Thu, 4 Feb 2021 09:30:45 -0800 In-Reply-To: <20210204173045.1138504-1-dlatypov@google.com> Message-Id: <20210204173045.1138504-4-dlatypov@google.com> Mime-Version: 1.0 References: <20210204173045.1138504-1-dlatypov@google.com> X-Mailer: git-send-email 2.30.0.365.g02bc693789-goog Subject: [PATCH v2 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)