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 C56AF248BA1; Wed, 15 Jan 2025 10:49:34 +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=1736938174; cv=none; b=buAj4+OZzM+yJ+Sc338uI7dQKSsllGgLyXflVJZzMWqVbo+ZQd/DAK8v3JXK0iI5foMFR9h6LCvZdFWX36TfNjwu8yJcCd2qXUrACFbOlMRHYq6A08uVl4PxT9Ib8J8XU7/4IKgWqsBwyMkF7O/3c9lmhhOdVd8b+/f139mOr/8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736938174; c=relaxed/simple; bh=LL6G4yCqeJ7Z55shYK0thCXdg+1TrAxK0o2VOoci3qw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=lPSJ1QpLPHhdpl5xQA2UapF7yLcekavCOASN8mDVyU0K6JM5pFbsJdcWxGbd6rOulIvbIo+iMmo1LLqaWNjKILaOLITmbCdoQMQvDKhDaNeAvvwjLBxNG7VZaqU9pEDM02Jap8YLBhNLSRln6ZrGgo0Brbyav9B6Rguj735BayI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=WKvf6IKK; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="WKvf6IKK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4AB8EC4CEDF; Wed, 15 Jan 2025 10:49:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1736938174; bh=LL6G4yCqeJ7Z55shYK0thCXdg+1TrAxK0o2VOoci3qw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WKvf6IKKF5UJPods7HaJBD2gRHSQiGtLVzC5U/c5XPwxuhegrG5VJ+Ahfcxcd8amH +SV35YzfhC9M7whaPNCjO515SX1hxTNBk05u93s6j7qFweGwgYDVba+MgxUPckrPQp 1GhmIHIYV4VRitVJfVyEK0099s9bmWd9rcsY6pT0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Waiman Long , Tejun Heo , Sasha Levin Subject: [PATCH 6.12 106/189] cgroup/cpuset: Prevent leakage of isolated CPUs into sched domains Date: Wed, 15 Jan 2025 11:36:42 +0100 Message-ID: <20250115103610.684207139@linuxfoundation.org> X-Mailer: git-send-email 2.48.0 In-Reply-To: <20250115103606.357764746@linuxfoundation.org> References: <20250115103606.357764746@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Waiman Long [ Upstream commit 9b496a8bbed9cc292b0dfd796f38ec58b6d0375f ] Isolated CPUs are not allowed to be used in a non-isolated partition. The only exception is the top cpuset which is allowed to contain boot time isolated CPUs. Commit ccac8e8de99c ("cgroup/cpuset: Fix remote root partition creation problem") introduces a simplified scheme of including only partition roots in sched domain generation. However, it does not properly account for this exception case. This can result in leakage of isolated CPUs into a sched domain. Fix it by making sure that isolated CPUs are excluded from the top cpuset before generating sched domains. Also update the way the boot time isolated CPUs are handled in test_cpuset_prs.sh to make sure that those isolated CPUs are really isolated instead of just skipping them in the tests. Fixes: ccac8e8de99c ("cgroup/cpuset: Fix remote root partition creation problem") Signed-off-by: Waiman Long Signed-off-by: Tejun Heo Signed-off-by: Sasha Levin --- kernel/cgroup/cpuset.c | 10 +++++- .../selftests/cgroup/test_cpuset_prs.sh | 33 +++++++++++-------- 2 files changed, 28 insertions(+), 15 deletions(-) diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index a4dd285cdf39..c431c50512bd 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -862,7 +862,15 @@ static int generate_sched_domains(cpumask_var_t **domains, */ if (cgrpv2) { for (i = 0; i < ndoms; i++) { - cpumask_copy(doms[i], csa[i]->effective_cpus); + /* + * The top cpuset may contain some boot time isolated + * CPUs that need to be excluded from the sched domain. + */ + if (csa[i] == &top_cpuset) + cpumask_and(doms[i], csa[i]->effective_cpus, + housekeeping_cpumask(HK_TYPE_DOMAIN)); + else + cpumask_copy(doms[i], csa[i]->effective_cpus); if (dattr) dattr[i] = SD_ATTR_INIT; } diff --git a/tools/testing/selftests/cgroup/test_cpuset_prs.sh b/tools/testing/selftests/cgroup/test_cpuset_prs.sh index 03c1bdaed2c3..400a696a0d21 100755 --- a/tools/testing/selftests/cgroup/test_cpuset_prs.sh +++ b/tools/testing/selftests/cgroup/test_cpuset_prs.sh @@ -86,15 +86,15 @@ echo "" > test/cpuset.cpus # # If isolated CPUs have been reserved at boot time (as shown in -# cpuset.cpus.isolated), these isolated CPUs should be outside of CPUs 0-7 +# cpuset.cpus.isolated), these isolated CPUs should be outside of CPUs 0-8 # that will be used by this script for testing purpose. If not, some of -# the tests may fail incorrectly. These isolated CPUs will also be removed -# before being compared with the expected results. +# the tests may fail incorrectly. These pre-isolated CPUs should stay in +# an isolated state throughout the testing process for now. # BOOT_ISOLCPUS=$(cat $CGROUP2/cpuset.cpus.isolated) if [[ -n "$BOOT_ISOLCPUS" ]] then - [[ $(echo $BOOT_ISOLCPUS | sed -e "s/[,-].*//") -le 7 ]] && + [[ $(echo $BOOT_ISOLCPUS | sed -e "s/[,-].*//") -le 8 ]] && skip_test "Pre-isolated CPUs ($BOOT_ISOLCPUS) overlap CPUs to be tested" echo "Pre-isolated CPUs: $BOOT_ISOLCPUS" fi @@ -683,15 +683,19 @@ check_isolcpus() EXPECT_VAL2=$EXPECT_VAL fi + # + # Appending pre-isolated CPUs + # Even though CPU #8 isn't used for testing, it can't be pre-isolated + # to make appending those CPUs easier. + # + [[ -n "$BOOT_ISOLCPUS" ]] && { + EXPECT_VAL=${EXPECT_VAL:+${EXPECT_VAL},}${BOOT_ISOLCPUS} + EXPECT_VAL2=${EXPECT_VAL2:+${EXPECT_VAL2},}${BOOT_ISOLCPUS} + } + # # Check cpuset.cpus.isolated cpumask # - if [[ -z "$BOOT_ISOLCPUS" ]] - then - ISOLCPUS=$(cat $ISCPUS) - else - ISOLCPUS=$(cat $ISCPUS | sed -e "s/,*$BOOT_ISOLCPUS//") - fi [[ "$EXPECT_VAL2" != "$ISOLCPUS" ]] && { # Take a 50ms pause and try again pause 0.05 @@ -731,8 +735,6 @@ check_isolcpus() fi done [[ "$ISOLCPUS" = *- ]] && ISOLCPUS=${ISOLCPUS}$LASTISOLCPU - [[ -n "BOOT_ISOLCPUS" ]] && - ISOLCPUS=$(echo $ISOLCPUS | sed -e "s/,*$BOOT_ISOLCPUS//") [[ "$EXPECT_VAL" = "$ISOLCPUS" ]] } @@ -836,8 +838,11 @@ run_state_test() # if available [[ -n "$ICPUS" ]] && { check_isolcpus $ICPUS - [[ $? -ne 0 ]] && test_fail $I "isolated CPU" \ - "Expect $ICPUS, get $ISOLCPUS instead" + [[ $? -ne 0 ]] && { + [[ -n "$BOOT_ISOLCPUS" ]] && ICPUS=${ICPUS},${BOOT_ISOLCPUS} + test_fail $I "isolated CPU" \ + "Expect $ICPUS, get $ISOLCPUS instead" + } } reset_cgroup_states # -- 2.39.5