From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 11C6B18E05C for ; Mon, 9 Sep 2024 23:41:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725925305; cv=none; b=KwMJDr5uTaOvh7nS5kCmrTErN/pZhIWma+w7io5o0MTtdCpnNqkbUAjsibyRPTxdL3UFAqiTs3K8wDzG27Q5wD2W/IQhg8apSLFo9L4frJjIPEJDdNFXWAupVI012VMuvez8XyeYoKv6DlwyoXJKCvfVmplqbFvpi6Ms3dz6btA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725925305; c=relaxed/simple; bh=xd9BDlstJ7xGVPBQ+9VTg0Knnf1ecfeK2d+Ws4CKW34=; h=Date:To:From:Subject:Message-Id; b=iQbnWV6x9B2oa98o68Sg6ZVUY930J4ut5lvM6tYsIGRmBwX9Gm6hAtBDka+ozY/L3uzoqu0yXB6n3+rcRBF+yIcj5mOPEM04H6SpOIEgBdxtC2K0zLnzmlEYP/8e59vHOXhsQI6uegKIsvfesj/e5/lBhVioed3BvMgMGxxEEew= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=cBPa+Okf; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="cBPa+Okf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DB0CBC4CEC5; Mon, 9 Sep 2024 23:41:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1725925304; bh=xd9BDlstJ7xGVPBQ+9VTg0Knnf1ecfeK2d+Ws4CKW34=; h=Date:To:From:Subject:From; b=cBPa+Okf1TYBwh6uzVRpM2nR0glh6sA9yHgbMs+cSXl6ry5U1IdI0EZBcZDXG9CQW tzB1p5wCd7oa5jsTPRn6jWWUYD3Ovh0wMLXJt3zxAa/rUqS4rjueWHWca+CYUldlvu a9NxSf4XhssyQl0tB44Kf/Qr66GAAElp+GqlK4lc= Date: Mon, 09 Sep 2024 16:41:44 -0700 To: mm-commits@vger.kernel.org,linux@roeck-us.net,davidgow@google.com,brendanhiggins@google.com,sj@kernel.org,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] mm-damon-tests-core-kunit-skip-damon_test_nr_accesses_to_accesses_bp-if-aggr_interval-is-zero.patch removed from -mm tree Message-Id: <20240909234144.DB0CBC4CEC5@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: mm/damon/tests/core-kunit: skip damon_test_nr_accesses_to_accesses_bp() if aggr_interval is zero has been removed from the -mm tree. Its filename was mm-damon-tests-core-kunit-skip-damon_test_nr_accesses_to_accesses_bp-if-aggr_interval-is-zero.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: SeongJae Park Subject: mm/damon/tests/core-kunit: skip damon_test_nr_accesses_to_accesses_bp() if aggr_interval is zero Date: Thu, 5 Sep 2024 09:24:23 -0700 The aggregation interval of test purpose damon_attrs for damon_test_nr_accesses_to_accesses_bp() becomes zero on 32 bit architecture, since size of int and long types are same. As a result, damon_nr_accesses_to_accesses_bp() call with the test data triggers divide-by-zero exception. damon_nr_accesses_to_accesses_bp() shouldn't be called with such data, and the non-test code avoids that by checking the case on damon_update_monitoring_results(). Skip the test code in the case, and add an explicit caution of the case on the comment for the test target function. Link: https://lkml.kernel.org/r/20240905162423.74053-1-sj@kernel.org Fixes: 5e06ad590096 ("mm/damon/core-test: test max_nr_accesses overflow caused divide-by-zero") Signed-off-by: SeongJae Park Reported-by: Guenter Roeck Closes: https://lore.kernel.org/c771b962-a58f-435b-89e4-1211a9323181@roeck-us.net Cc: Brendan Higgins Cc: David Gow Cc: Guenter Roeck Signed-off-by: Andrew Morton --- mm/damon/core.c | 8 +++++++- mm/damon/tests/core-kunit.h | 12 ++++++++++++ 2 files changed, 19 insertions(+), 1 deletion(-) --- a/mm/damon/core.c~mm-damon-tests-core-kunit-skip-damon_test_nr_accesses_to_accesses_bp-if-aggr_interval-is-zero +++ a/mm/damon/core.c @@ -552,7 +552,13 @@ static unsigned int damon_accesses_bp_to return accesses_bp * damon_max_nr_accesses(attrs) / 10000; } -/* convert nr_accesses to access ratio in bp (per 10,000) */ +/* + * Convert nr_accesses to access ratio in bp (per 10,000). + * + * Callers should ensure attrs.aggr_interval is not zero, like + * damon_update_monitoring_results() does . Otherwise, divide-by-zero would + * happen. + */ static unsigned int damon_nr_accesses_to_accesses_bp( unsigned int nr_accesses, struct damon_attrs *attrs) { --- a/mm/damon/tests/core-kunit.h~mm-damon-tests-core-kunit-skip-damon_test_nr_accesses_to_accesses_bp-if-aggr_interval-is-zero +++ a/mm/damon/tests/core-kunit.h @@ -320,6 +320,18 @@ static void damon_test_nr_accesses_to_ac .aggr_interval = ((unsigned long)UINT_MAX + 1) * 10 }; + /* + * In some cases such as 32bit architectures where UINT_MAX is + * ULONG_MAX, attrs.aggr_interval becomes zero. Calling + * damon_nr_accesses_to_accesses_bp() in the case will cause + * divide-by-zero. Such case is prohibited in normal execution since + * the caution is documented on the comment for the function, and + * damon_update_monitoring_results() does the check. Skip the test in + * the case. + */ + if (!attrs.aggr_interval) + kunit_skip(test, "aggr_interval is zero."); + KUNIT_EXPECT_EQ(test, damon_nr_accesses_to_accesses_bp(123, &attrs), 0); } _ Patches currently in -mm which might be from sj@kernel.org are