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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 F19B3C433B4 for ; Tue, 18 May 2021 09:49:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D23E5613F5 for ; Tue, 18 May 2021 09:49:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242318AbhERJuQ (ORCPT ); Tue, 18 May 2021 05:50:16 -0400 Received: from mail.kernel.org ([198.145.29.99]:50126 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348135AbhERJt1 (ORCPT ); Tue, 18 May 2021 05:49:27 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id BD153613CB; Tue, 18 May 2021 09:48:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1621331289; bh=nWVmEPeR0hM9A1fN5XIKmBdskSrJ1G92PsqLDEhYaSM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bJZqDMYB1gHPG9YMTA0G3FEGVzf5TtzSg0BgVnZHPLaioxVDGWkxXh8gwz/OvrV6a d9QkWGIU208DCKa/xvr3mO7xf8vPcLQ2XYb3DyrfBR/iom3FBG3Bh4TFhJb7gMXYbQ nny2uINhbOB96DwiMBfoVcXVt+l1BQ9+RR2EQxK65Ltxuh4hAQU5XREskaMI56htpu 7oRAlRX4ZpVgEAUlSkoz7G/o6qi6RIp7p37jAJ9tBXOK7HbX2TYOPr3BPeo8Ck8A2P 7NQ/uHCz1LgDyo8aUGO95xjD2rMEqBqzCOTyLYbV3v25w5ag6+TYDrqIc3VPeuOO9y 1NELW1ysbLwmQ== 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 , "Rafael J. Wysocki" , kernel-team@android.com Subject: [PATCH v6 09/21] sched: Reject CPU affinity changes based on task_cpu_possible_mask() Date: Tue, 18 May 2021 10:47:13 +0100 Message-Id: <20210518094725.7701-10-will@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210518094725.7701-1-will@kernel.org> References: <20210518094725.7701-1-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 482f7fdca0e8..21da3d7f9e47 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2350,6 +2350,7 @@ static int __set_cpus_allowed_ptr(struct task_struct *p, u32 flags) { 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; @@ -2370,6 +2371,9 @@ static int __set_cpus_allowed_ptr(struct task_struct *p, * set_cpus_allowed_common() and actually reset p->cpus_ptr. */ cpu_valid_mask = cpu_online_mask; + } else if (!cpumask_subset(new_mask, cpu_allowed_mask)) { + ret = -EINVAL; + goto out; } /* -- 2.31.1.751.gd2f1c929bd-goog