From nobody Sun Dec 28 02:40:20 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 57034C19774 for ; Wed, 13 Dec 2023 19:03:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1442031AbjLMTDq (ORCPT ); Wed, 13 Dec 2023 14:03:46 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33630 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1379292AbjLMTDm (ORCPT ); Wed, 13 Dec 2023 14:03:42 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9126595 for ; Wed, 13 Dec 2023 11:03:49 -0800 (PST) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BC743C433C8; Wed, 13 Dec 2023 19:03:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1702494229; bh=gjBQjP/YI+pvMOKNh4ddMdbLJ3KLmfM9HXn1Dp4kPVs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gh6j4zF8l93bobVI7GSErZD+7LyrzAOafaTw/R+gygXqiWV4CRdqWwXQ4WHnfcO5A ntCVTNa3MG2BjUATa9SvAKwQAfINk5MJbH1cQsimTz2xBRm2XyU16JA/pkCDCVZBLM tYqx26QhH06nd6+RI/CnV0NU7hK5ynOAW+Z0EaxqXgVK7aTJLDK+cN15J+KLBe+wGl FPY1GTm8dlM/DZ8CdH2eMVZ9cww7cSXDsMBAbUrukA7Khyyau/bnOZiSGqHIhpwnXk UQuZluFbU+/gS0nN3hGdfFYeZSaojRVgc0zs0RTAEI3p5ZqKWxiCp7cU9I6UkJIWWW PXaXBm0veoOYA== From: SeongJae Park To: Andrew Morton Cc: SeongJae Park , damon@lists.linux.dev, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH 2/6] mm/damon/core-test: test max_nr_accesses overflow caused divide-by-zero Date: Wed, 13 Dec 2023 19:03:34 +0000 Message-Id: <20231213190338.54146-3-sj@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231213190338.54146-1-sj@kernel.org> References: <20231213190338.54146-1-sj@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Commit 35f5d94187a6 ("mm/damon: implement a function for max nr_accesses safe calculation") has fixed an overflow bug that could cause divide-by-zero. Add a kunit test for the bug to ensure similar bugs are not introduced again. Signed-off-by: SeongJae Park --- mm/damon/core-test.h | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/mm/damon/core-test.h b/mm/damon/core-test.h index 876e398557b0..0cee634f3544 100644 --- a/mm/damon/core-test.h +++ b/mm/damon/core-test.h @@ -302,6 +302,16 @@ static void damon_test_set_regions(struct kunit *test) damon_destroy_target(t); } =20 +static void damon_test_nr_accesses_to_accesses_bp(struct kunit *test) +{ + struct damon_attrs attrs =3D { + .sample_interval =3D 10, + .aggr_interval =3D ((unsigned long)UINT_MAX + 1) * 10 + }; + + KUNIT_EXPECT_EQ(test, damon_nr_accesses_to_accesses_bp(123, &attrs), 0); +} + static void damon_test_update_monitoring_result(struct kunit *test) { struct damon_attrs old_attrs =3D { @@ -487,6 +497,7 @@ static struct kunit_case damon_test_cases[] =3D { KUNIT_CASE(damon_test_split_regions_of), KUNIT_CASE(damon_test_ops_registration), KUNIT_CASE(damon_test_set_regions), + KUNIT_CASE(damon_test_nr_accesses_to_accesses_bp), KUNIT_CASE(damon_test_update_monitoring_result), KUNIT_CASE(damon_test_set_attrs), KUNIT_CASE(damon_test_moving_sum), --=20 2.34.1