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=-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=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 1D1AEC433DB for ; Thu, 4 Feb 2021 22:56:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D5A2764FAE for ; Thu, 4 Feb 2021 22:56:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230033AbhBDW4W (ORCPT ); Thu, 4 Feb 2021 17:56:22 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50664 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229785AbhBDW4Q (ORCPT ); Thu, 4 Feb 2021 17:56:16 -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 47204C061794 for ; Thu, 4 Feb 2021 14:55:01 -0800 (PST) Received: by mail-yb1-xb49.google.com with SMTP id q191so4838619ybg.4 for ; Thu, 04 Feb 2021 14:55:01 -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=Wkqh1wBZi1KMSWP9n4B3+7R4NMp7xQIbcrZ87gljot4=; b=iYbKyTjxF+2utdWW8EqdT/kRukPx6bdkOrTGffBQ3EQrvhGlQhMUHl9GQzbCEjBDRk WyU4ioaBh/EghQ4qsB08wQUS+sh9s9/zbXYZUP6fnKZd9xakktG/+CYlj12MKFPFaJC+ RPm4eTDjCGHR9Eyt6MO6LqsklaY2Wtfft1AJ6oFyvC3cE/eCjZQFNRwwkHXe8Oil1Bk9 UgfjWtqPaiBO7r4jVqQb77XUeK5LvbHuUEObXh43X63HHx73M6IwvkvgNll9ofNG/huK e0PGax3yohgTMXAN7PNdMPkK9359NPAuCHEPOhMt2wENbMkcX49Ce3Lbc1kRA4TTv3S3 ZfWQ== 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=Wkqh1wBZi1KMSWP9n4B3+7R4NMp7xQIbcrZ87gljot4=; b=NKPmgZNJVol1TEr9m0YfTBEX+cKYDOJW6dyCCvfbV+VVUok39rcUn9XGaxrcQ9ePNe Vwqpjtq4X89nVJ0oweCctl2C8B9s4rV/gJxJCAi5NAsYZH8AKs4XSuj6238hy5tyXXu4 Pp4ZR6VnDv4x/R50K21KFcTvLn+lTbRMoR9z7qV9SypYdd7anduCaH8p17sTbNMGEl7P Lvu1GncGAjMaFjn/g5e5avd8RZnL+9u9cfCB+vfcXJrE7O1S1aroWunaaacUf6BYxx1c SnoUwcmLa1UtrwYOo54UE8YZwLp4xVY7xfpvor4lpfc2DKC5XNcUm0+oQNtNomif17aG u/mg== X-Gm-Message-State: AOAM5309TlbAD2Z/FkPhO/kvaWLUWN9BtEroEUip5J7K2Hvjm8Lsthiw +kVYGfo1lWAoD08YEuIZWD/4FqpJDS1BsQ== X-Google-Smtp-Source: ABdhPJwoINV61XBqm1+2y6JBPKINVE5ci4YcuQgf9RpZwrWA4UcY6q/lgnsC0tACbu0OUhf3hAuSoOwt1qLA3w== 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:a25:d441:: with SMTP id m62mr1482057ybf.109.1612479300511; Thu, 04 Feb 2021 14:55:00 -0800 (PST) Date: Thu, 4 Feb 2021 14:54:48 -0800 In-Reply-To: <20210204225448.1393741-1-dlatypov@google.com> Message-Id: <20210204225448.1393741-4-dlatypov@google.com> Mime-Version: 1.0 References: <20210204225448.1393741-1-dlatypov@google.com> X-Mailer: git-send-email 2.30.0.478.g8a0d178c01-goog Subject: [PATCH v3 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 Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 Reviewed-by: Brendan Higgins --- 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) -- 2.30.0.478.g8a0d178c01-goog