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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A0250C77B61 for ; Tue, 25 Apr 2023 11:44:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233921AbjDYLol (ORCPT ); Tue, 25 Apr 2023 07:44:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45208 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233932AbjDYLoj (ORCPT ); Tue, 25 Apr 2023 07:44:39 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EC11349C2 for ; Tue, 25 Apr 2023 04:43:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1682423032; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=vFQziVpAX6XaFGXqO40sBdWG90AbxvK36TAoQxxNkWo=; b=G/yuocio0lYeF5A2R45iQi3YeGd9mYuOuLxTxHVtds970oETROG3diOu9w4YvZMg923iFm QB6HRhHMSkF4SZApBHX5XO4t8u9ezymJVqO7UCuoydZnZQqZHrjIRYS0M+XgRlq/EFIOzg iud4TiGl9TkQ49RNuDQyF+FP7G2hKhI= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-131-UQkMa4ztO0O8A3npY_Q1aA-1; Tue, 25 Apr 2023 07:43:43 -0400 X-MC-Unique: UQkMa4ztO0O8A3npY_Q1aA-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 5506F1C08786; Tue, 25 Apr 2023 11:43:42 +0000 (UTC) Received: from fedora.redhat.com (unknown [10.22.32.181]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5A307C15BA0; Tue, 25 Apr 2023 11:43:35 +0000 (UTC) From: Wander Lairson Costa To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Ian Rogers , Adrian Hunter , Will Deacon , Waiman Long , Boqun Feng , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Daniel Bristot de Oliveira , Valentin Schneider , "Eric W. Biederman" , Wander Lairson Costa , Kefeng Wang , Michael Ellerman , Oleg Nesterov , Andrew Morton , "Liam R. Howlett" , Christian Brauner , Kees Cook , Andrei Vagin , Shakeel Butt , linux-kernel@vger.kernel.org (open list), linux-perf-users@vger.kernel.org (open list:PERFORMANCE EVENTS SUBSYSTEM) Cc: Sebastian Andrzej Siewior Subject: [PATCH v7 1/3] sched/core: warn on call put_task_struct in invalid context Date: Tue, 25 Apr 2023 08:43:01 -0300 Message-Id: <20230425114307.36889-2-wander@redhat.com> In-Reply-To: <20230425114307.36889-1-wander@redhat.com> References: <20230425114307.36889-1-wander@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.1 on 10.11.54.8 Precedence: bulk List-ID: X-Mailing-List: linux-perf-users@vger.kernel.org Under PREEMPT_RT, spinlocks become sleepable locks. put_task_struct() indirectly acquires a spinlock. Therefore, it can't be called in atomic/interrupt context in RT kernels. To prevent such conditions, add a check for atomic/interrupt context before calling put_task_struct(). Signed-off-by: Wander Lairson Costa Suggested-by: Sebastian Andrzej Siewior --- include/linux/sched/task.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/include/linux/sched/task.h b/include/linux/sched/task.h index 357e0068497c..b597b97b1f8f 100644 --- a/include/linux/sched/task.h +++ b/include/linux/sched/task.h @@ -113,14 +113,28 @@ static inline struct task_struct *get_task_struct(struct task_struct *t) extern void __put_task_struct(struct task_struct *t); +#define PUT_TASK_RESCHED_OFFSETS \ + (rcu_preempt_depth() << MIGHT_RESCHED_RCU_SHIFT) + +#define __put_task_might_resched() \ + __might_resched(__FILE__, __LINE__, PUT_TASK_RESCHED_OFFSETS) + +#define put_task_might_resched() \ + do { \ + if (IS_ENABLED(CONFIG_PREEMPT_RT)) \ + __put_task_might_resched(); \ + } while (0) + static inline void put_task_struct(struct task_struct *t) { + put_task_might_resched(); if (refcount_dec_and_test(&t->usage)) __put_task_struct(t); } static inline void put_task_struct_many(struct task_struct *t, int nr) { + put_task_might_resched(); if (refcount_sub_and_test(nr, &t->usage)) __put_task_struct(t); } -- 2.40.0