From nobody Sun Sep 14 16:23:33 2025 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 B21A5C05027 for ; Fri, 20 Jan 2023 15:04:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231292AbjATPEm (ORCPT ); Fri, 20 Jan 2023 10:04:42 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38588 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231288AbjATPEc (ORCPT ); Fri, 20 Jan 2023 10:04:32 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BFF84B2E66 for ; Fri, 20 Jan 2023 07:03:49 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1674227028; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Lda/+ml5+8vWZrx9vfKLtfMa+7nWIziVhjlRSwPRz3M=; b=dLYPoSVO6rnvIsMAH9X9Bq66MUJXwYdu+oCku7s5I8eIjgZqlH2i4Qk4sN/zS26eSKFlmp VPRd5N6jYbfUGIPrHsmSYUdiM8xU8u4wVhvQLYcUCkc8aI5KRqechgR1B0VeSA/WXxylEf q9+3J5No++34u6JmW4kGpCeojZBK6fI= 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-554-bhRqpXYPNP-zoGd957nf9Q-1; Fri, 20 Jan 2023 10:03:43 -0500 X-MC-Unique: bhRqpXYPNP-zoGd957nf9Q-1 Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.rdu2.redhat.com [10.11.54.10]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 43D06800DB5; Fri, 20 Jan 2023 15:03:42 +0000 (UTC) Received: from fedora.redhat.com (unknown [10.22.32.187]) by smtp.corp.redhat.com (Postfix) with ESMTP id A7F02492B02; Fri, 20 Jan 2023 15:03:37 +0000 (UTC) From: Wander Lairson Costa To: Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Daniel Bristot de Oliveira , Valentin Schneider , "Eric W. Biederman" , Geert Uytterhoeven , Stafford Horne , "Russell King (Oracle)" , Oleg Nesterov , Wander Lairson Costa , Kefeng Wang , Andrew Morton , Thomas Gleixner , Sebastian Andrzej Siewior , Andy Lutomirski , "Liam R. Howlett" , Fenghua Yu , Andrei Vagin , linux-kernel@vger.kernel.org (open list) Subject: [PATCH v2 4/4] sched/core: use put_task_struct_atomic_safe() to avoid potential splat Date: Fri, 20 Jan 2023 12:02:42 -0300 Message-Id: <20230120150246.20797-5-wander@redhat.com> In-Reply-To: <20230120150246.20797-1-wander@redhat.com> References: <20230120150246.20797-1-wander@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.1 on 10.11.54.10 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" push_cpu_stop() is called form a context in which it must not sleep. Since push_cpu_stop() calls put_task_struct(), it potentially can sleep under PREEMPT_RT if the usage count reaches zero. Use put_task_struct_atomic_safe(0 instead to avoid this potential splat. Signed-off-by: Wander Lairson Costa Cc: Thomas Gleixner --- kernel/sched/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index c437260e19b0..e5d0c66cb90c 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2565,7 +2565,7 @@ int push_cpu_stop(void *arg) raw_spin_rq_unlock(rq); raw_spin_unlock_irq(&p->pi_lock); =20 - put_task_struct(p); + put_task_struct_atomic_safe(p); return 0; } =20 --=20 2.39.0