From nobody Sat Apr 11 11:10:14 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 916AAC25B08 for ; Fri, 12 Aug 2022 20:40:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236043AbiHLUkH (ORCPT ); Fri, 12 Aug 2022 16:40:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33500 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230445AbiHLUkD (ORCPT ); Fri, 12 Aug 2022 16:40:03 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id A40AFB5171 for ; Fri, 12 Aug 2022 13:40:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1660336801; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=PTybH4D4WwOeqo3rN415vbeLaTvaxhsUDN/KB9esUqw=; b=N2ehBv8M/aSpVdNfbQP+szRN/WIHAAoLqVBZdIT/IVK16W8HmDORXb/NZeDQnQ2+j5IrxW +vFtp0RX/M+xJ8DwUHSl+t/SB2L0/5aBYUoc3avi/aJMeqvpZxf764ZGKveh0L1V+fmdcG Un07iqrqrNPT63Wi/8g2w2ycsLFgSZs= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-596-wpjNd6xdOL6kePHvfDkgYw-1; Fri, 12 Aug 2022 16:39:59 -0400 X-MC-Unique: wpjNd6xdOL6kePHvfDkgYw-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 1D3DB1857F02; Fri, 12 Aug 2022 20:39:59 +0000 (UTC) Received: from llong.com (unknown [10.22.32.88]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6E51CC15BA6; Fri, 12 Aug 2022 20:39:58 +0000 (UTC) From: Waiman Long To: Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Daniel Bristot de Oliveira , Valentin Schneider , Tejun Heo , Zefan Li , Johannes Weiner , Will Deacon Cc: cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, Linus Torvalds , Waiman Long Subject: [PATCH v3 2/3] sched: Provide copy_user_cpus_mask() to copy out user mask Date: Fri, 12 Aug 2022 16:39:28 -0400 Message-Id: <20220812203929.364341-3-longman@redhat.com> In-Reply-To: <20220812203929.364341-1-longman@redhat.com> References: <20220812203929.364341-1-longman@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 2.85 on 10.11.54.8 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Since accessing the content of the user_cpus_ptr requires lock protection to ensure its validity, provide a helper function copy_user_cpus_mask() to facilitate its reading. Signed-off-by: Waiman Long --- include/linux/sched.h | 1 + kernel/sched/core.c | 18 ++++++++++++++++++ 2 files changed, 19 insertions(+) diff --git a/include/linux/sched.h b/include/linux/sched.h index cf7206a9b29a..e06bc1cbccca 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1831,6 +1831,7 @@ extern int task_can_attach(struct task_struct *p, con= st struct cpumask *cs_effec extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumas= k *new_mask); extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumas= k *new_mask); extern int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *= src, int node); +extern struct cpumask *copy_user_cpus_mask(struct task_struct *p, struct c= pumask *user_mask); extern void release_user_cpus_ptr(struct task_struct *p); extern int dl_task_check_affinity(struct task_struct *p, const struct cpum= ask *mask); extern void force_compatible_cpus_allowed_ptr(struct task_struct *p); diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 7e2576068331..4d3b10e91e1a 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2619,6 +2619,24 @@ void release_user_cpus_ptr(struct task_struct *p) kfree(clear_user_cpus_ptr(p)); } =20 +/* + * Return the copied mask pointer or NULL if user mask not available. + */ +struct cpumask *copy_user_cpus_mask(struct task_struct *p, + struct cpumask *user_mask) +{ + struct rq_flags rf; + struct rq *rq =3D task_rq_lock(p, &rf); + struct cpumask *mask =3D NULL; + + if (p->user_cpus_ptr) { + cpumask_copy(user_mask, p->user_cpus_ptr); + mask =3D user_mask; + } + task_rq_unlock(rq, p, &rf); + return mask; +} + /* * This function is wildly self concurrent; here be dragons. * --=20 2.31.1