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=-13.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 07346C388F7 for ; Fri, 13 Nov 2020 09:38:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 96F6A22265 for ; Fri, 13 Nov 2020 09:38:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="hJ0sm9lH" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726591AbgKMJiV (ORCPT ); Fri, 13 Nov 2020 04:38:21 -0500 Received: from mail.kernel.org ([198.145.29.99]:50766 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726554AbgKMJiS (ORCPT ); Fri, 13 Nov 2020 04:38:18 -0500 Received: from localhost.localdomain (236.31.169.217.in-addr.arpa [217.169.31.236]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C52D92225E; Fri, 13 Nov 2020 09:38:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1605260297; bh=mEksWh+4+8NCkqXKHhes2krWnYnJe6uXQp/IwoxcPus=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hJ0sm9lHRn2NQcCZTgSUk4cOUP3hLVjvsmBJGt7GyQvLrLB3sw/PHAn3OW4g2y+xf i4IFIQJKyA13wq70oIJuWjkVxl9hcZ6/JOWAJJf+Aemj5zNMUOoqU6CISQ3mo34AUi mJd2vhiTsZioGZxsitQFkZYPgfNNdfOeu7ILmrbE= From: Will Deacon 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 v3 11/14] sched: Reject CPU affinity changes based on arch_cpu_allowed_mask() Date: Fri, 13 Nov 2020 09:37:16 +0000 Message-Id: <20201113093720.21106-12-will@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20201113093720.21106-1-will@kernel.org> References: <20201113093720.21106-1-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 arch_cpu_allowed_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. 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 8df38ebfe769..13bdb2ae4d3f 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1877,6 +1877,7 @@ static int __set_cpus_allowed_ptr_locked(struct task_struct *p, struct rq_flags *rf) { const struct cpumask *cpu_valid_mask = cpu_active_mask; + const struct cpumask *cpu_allowed_mask = arch_cpu_allowed_mask(p); unsigned int dest_cpu; int ret = 0; @@ -1887,6 +1888,9 @@ static int __set_cpus_allowed_ptr_locked(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; } /* -- 2.29.2.299.gdc1121823c-goog