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[23.128.96.19]) by mx.google.com with ESMTPS id c8-20020a170902d48800b00153b2d1645csi2343607plg.100.2022.05.18.01.59.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 18 May 2022 01:59:24 -0700 (PDT) Received-SPF: softfail (google.com: domain of transitioning linux-kernel-owner@vger.kernel.org does not designate 23.128.96.19 as permitted sender) client-ip=23.128.96.19; Authentication-Results: mx.google.com; dkim=pass header.i=@linutronix.de header.s=2020 header.b=soOUlAjy; dkim=neutral (no key) header.i=@linutronix.de header.s=2020e header.b=s8ytQ9+p; spf=softfail (google.com: domain of transitioning linux-kernel-owner@vger.kernel.org does not designate 23.128.96.19 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=linutronix.de Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 4BD052FFD7; Wed, 18 May 2022 01:57:31 -0700 (PDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233751AbiERI4T (ORCPT + 99 others); Wed, 18 May 2022 04:56:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46434 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233634AbiERIzp (ORCPT ); Wed, 18 May 2022 04:55:45 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EC283134E1F for ; Wed, 18 May 2022 01:55:40 -0700 (PDT) From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1652864138; 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: in-reply-to:in-reply-to:references:references; bh=UcxXOvDlY2eSV87H7dyKFcZrRDyg8Lk6SHYT9Da8KPE=; b=soOUlAjykXqqw5GqpV6bSf3DeibNHLnZ6JJhWS1tz0XWIkl95zBIzfxO/1jYTTkPn7OsfR h9KH72lIOoy5ev2WAbVGxhYEV0UHr2KAErgvAN1KPJxYGEZxGH25UrMY3en69mYTENKrPF NWMslFjnTkUxO1JgT9hmxu9kpizZF6w1xAd4mdoeZdgbFMLG+NU3pXV0jP5WByg8CYdCpV KttSXwYBw50EDz8AeuzTfGFM+0tvi6WSJgIQrTymJjyiCr/aHAqGL8lv66v1uPXQ+v2gh+ MByCIiIZ5Z9+T7SHN/04HEYtfYgKKcFVcYqPX2LlBBbnHk8GNgi01h46MAMIqg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1652864138; 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: in-reply-to:in-reply-to:references:references; bh=UcxXOvDlY2eSV87H7dyKFcZrRDyg8Lk6SHYT9Da8KPE=; b=s8ytQ9+po5ZeGiw2qixlDDlIyKp3zZx4e06fhU3rnjk9Nc9yTZX0bFm6uZVRwGas7XFl9L D1ZwWtaL2qvHAZAw== To: Chao Liu , linux-kernel@vger.kernel.org, hewenliang4@huawei.com Cc: steven.price@arm.com, Peter Zijlstra Subject: Re: [PATCH] cpu/hotplug: check the return value of idle_thread_get In-Reply-To: <20230327203728.159123-1-liuchao173@huawei.com> References: <20230327203728.159123-1-liuchao173@huawei.com> Date: Wed, 18 May 2022 10:55:37 +0200 Message-ID: <87leuzjk3a.ffs@tglx> MIME-Version: 1.0 Content-Type: text/plain X-Spam-Status: No, score=-2.0 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RDNS_NONE,SPF_HELO_NONE,T_SCC_BODY_TEXT_LINE autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Mar 27 2023 at 20:37, Chao Liu wrote: > ilde may be ERR_PTR() Yes, but if that happens in bringup_cpu() or finish_cpu() it would be a serious bug and the error pointer dereference would be the least of the problems. If the initial check in _cpu_up() failed for a CPU then the above functions cannot be invoked for that CPU ever. Thanks, tglx