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=-17.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 98D4EC2BBCA for ; Tue, 8 Dec 2020 13:30:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6F38623A79 for ; Tue, 8 Dec 2020 13:30:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729514AbgLHNaV (ORCPT ); Tue, 8 Dec 2020 08:30:21 -0500 Received: from mail.kernel.org ([198.145.29.99]:49434 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728786AbgLHNaQ (ORCPT ); Tue, 8 Dec 2020 08:30:16 -0500 From: Will Deacon Authentication-Results: mail.kernel.org; dkim=permerror (bad message/signature format) To: linux-arm-kernel@lists.infradead.org Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, Will Deacon , Catalin Marinas , Marc Zyngier , Greg Kroah-Hartman , Peter Zijlstra , Morten Rasmussen , Qais Yousef , Suren Baghdasaryan , Quentin Perret , Tejun Heo , Li Zefan , Johannes Weiner , Ingo Molnar , Juri Lelli , Vincent Guittot , kernel-team@android.com Subject: [PATCH v5 09/15] sched: Reject CPU affinity changes based on task_cpu_possible_mask() Date: Tue, 8 Dec 2020 13:28:29 +0000 Message-Id: <20201208132835.6151-10-will@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20201208132835.6151-1-will@kernel.org> References: <20201208132835.6151-1-will@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Reject explicit requests to change the affinity mask of a task via set_cpus_allowed_ptr() if the requested mask is not a subset of the mask returned by task_cpu_possible_mask(). This ensures that the 'cpus_mask' for a given task cannot contain CPUs which are incapable of executing it, except in cases where the affinity is forced. Reviewed-by: Quentin Perret Signed-off-by: Will Deacon --- kernel/sched/core.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 58474569a2ea..92ac3e53f50a 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1875,6 +1875,7 @@ static int __set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask, bool check) { const struct cpumask *cpu_valid_mask = cpu_active_mask; + const struct cpumask *cpu_allowed_mask = task_cpu_possible_mask(p); unsigned int dest_cpu; struct rq_flags rf; struct rq *rq; @@ -1888,6 +1889,9 @@ static int __set_cpus_allowed_ptr(struct task_struct *p, * Kernel threads are allowed on online && !active CPUs */ cpu_valid_mask = cpu_online_mask; + } else if (!cpumask_subset(new_mask, cpu_allowed_mask)) { + ret = -EINVAL; + goto out; } /* -- 2.29.2.576.ga3fc446d84-goog