From patchwork Fri Jul 30 11:24:32 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Will Deacon X-Patchwork-Id: 12411059 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=-17.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 AFEEDC4320E for ; Fri, 30 Jul 2021 11:27:37 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7DBDE6103B for ; Fri, 30 Jul 2021 11:27:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 7DBDE6103B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=RS0yFlbyyqqggOyEfd1ufNQJMvnifeoy9IBp+Xgc2RQ=; b=5A7H2sD4O2Bpnu tDM3OivqnhCsApT07SomxUvSjC29TUcR6EnbUz4IJXzp9B7D/QtBCQ6bN11FLFZNtywGQkmETktBG n5e2Fr9jJJIf5FEevCCdcrYIVJ79xQxlWNs4sOzbJUYINPqENl0I844DWXWEqOw+zaQTx/7j6ZN3S bDOoZEpSpYJaNnrIJppvG+hv5j+fGVE/ZPi5HKxfEJUnXzveXrePoLDX0BIOgFyOWCngez75fclJy /bNxuP+Yw0DbZDXrZWasQjw16NunaTwYkA1xiXSW4QwsPPyAPOndpED+2/j/c9OE9koCmOqmutMQS 5haJOaccT0UTQcBxjVqg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1m9QeP-008HiH-GO; Fri, 30 Jul 2021 11:26:01 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1m9Qdb-008HQK-QS for linux-arm-kernel@lists.infradead.org; Fri, 30 Jul 2021 11:25:13 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id D444961050; Fri, 30 Jul 2021 11:25:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1627644311; bh=7LEh2aSH3zOeZLBW6RvesFNL9tENH6Ea6cYaqsgwy6w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ozkspCQJ9DpTuoIeGCM/4uUwKbVKkHbVMiC0KEvv6XbS1PVA/kZ6mdQ53FueMXklP WheblWgaAXsP74bkbNQTnN5+Vp57tDXVrVi89tYSEE2PDLjd8S7XI0M+OPRdlnJ8VE boZBzgHXOOlC2KyaByjBmOHZm4PDgoHR3HGXSowAcmxrwQDXSxtQxtptPPJoXMugd5 FgwFshx/uhv8iXf3lLXQCPdJ4H8BXRFJtbyDrwWZPR3Z1tYyHwGjEnk+ff+aCwPiad XRzYq4NTTAlBT0tDVDMuBlGB6UCq+DnsqcKFt6Eryf+kSSsZxzLSM1yr+Q57MrXzKE M/e//lQTmGnyA== 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 , Johannes Weiner , Ingo Molnar , Juri Lelli , Vincent Guittot , "Rafael J. Wysocki" , Dietmar Eggemann , Daniel Bristot de Oliveira , Valentin Schneider , Mark Rutland , kernel-team@android.com, Valentin Schneider Subject: [PATCH v11 05/16] sched: Reject CPU affinity changes based on task_cpu_possible_mask() Date: Fri, 30 Jul 2021 12:24:32 +0100 Message-Id: <20210730112443.23245-6-will@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210730112443.23245-1-will@kernel.org> References: <20210730112443.23245-1-will@kernel.org> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210730_042511_926849_A24E14D3 X-CRM114-Status: GOOD ( 15.00 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.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: Valentin Schneider Reviewed-by: Quentin Perret Signed-off-by: Will Deacon --- kernel/sched/core.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 9fd598b8dac5..dbce9cd83a53 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2700,15 +2700,17 @@ 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; int ret = 0; + bool kthread = p->flags & PF_KTHREAD; rq = task_rq_lock(p, &rf); update_rq_clock(rq); - if (p->flags & PF_KTHREAD || is_migration_disabled(p)) { + if (kthread || is_migration_disabled(p)) { /* * Kernel threads are allowed on online && !active CPUs, * however, during cpu-hot-unplug, even these might get pushed @@ -2722,6 +2724,11 @@ static int __set_cpus_allowed_ptr(struct task_struct *p, cpu_valid_mask = cpu_online_mask; } + if (!kthread && !cpumask_subset(new_mask, cpu_allowed_mask)) { + ret = -EINVAL; + goto out; + } + /* * Must re-check here, to close a race against __kthread_bind(), * sched_setaffinity() is not guaranteed to observe the flag.