From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from szxga05-in.huawei.com (szxga05-in.huawei.com [45.249.212.191]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C69491DBB13; Wed, 6 Nov 2024 09:55:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.191 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730886923; cv=none; b=KbCdJGsKBaHfLXgdkGPX5s3+K6dATeiLLwtwk1dTzy2gRGob7sC/9JZejXUhvjmGSan47M2QwxKyDgYEbI7mvlsqNMw+1SwBPsZhL52w0oGGgekty5DJa4zYj2KC/498urKQmpMIwm2Zq3ymzI3fQ7g77WOlUY6gFSSXv5Nbwfg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730886923; c=relaxed/simple; bh=7Opzae6eJxnPKWoay/5QnazLgTYEphKcrHcvH2svUe4=; h=Message-ID:Date:MIME-Version:Subject:From:To:CC:References: In-Reply-To:Content-Type; b=F8TV+AxLM7bqJmuR/daVfNEfxlOalHZ7/RkAgXLrrGfU3AT7uBT8M5+mUJI8Ma0fw57O2RPgJ/IM3KdtJFDGCduv2FpvAOIc/e+YdOz1qOjVWybLWXdJpPeAaRr7sQxKEojUgARc7ZIk9/aYmWdgK8dBxkhVSJWmxdehDwNlB4k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.191 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.163.17]) by szxga05-in.huawei.com (SkyGuard) with ESMTP id 4Xk0rx1sg5z1jxjs; Wed, 6 Nov 2024 17:53:37 +0800 (CST) Received: from kwepemd200013.china.huawei.com (unknown [7.221.188.133]) by mail.maildlp.com (Postfix) with ESMTPS id 198391A0188; Wed, 6 Nov 2024 17:55:18 +0800 (CST) Received: from [10.67.110.108] (10.67.110.108) by kwepemd200013.china.huawei.com (7.221.188.133) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1258.34; Wed, 6 Nov 2024 17:55:17 +0800 Message-ID: <3d166642-4062-42ed-9e24-1771cd819110@huawei.com> Date: Wed, 6 Nov 2024 17:55:16 +0800 Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] arm64: uprobes: Optimize cache flushes for xol slot From: "Liao, Chang" To: , , , , , CC: , , References: <20240919121719.2148361-1-liaochang1@huawei.com> In-Reply-To: <20240919121719.2148361-1-liaochang1@huawei.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To kwepemd200013.china.huawei.com (7.221.188.133) Hi, Will and Catalin 在 2024/9/19 20:17, Liao Chang 写道: > On 09/23, Will Deacon wrote: >> However, we should use __GFP_ZERO anyway >> because I don't think it's a good idea to map an uninitialised page into >> userspace. > Agreed, and imo this even needs a separate "fix info leak" patch. > > Oleg. Given that Oleg's fix info leak patch has been merged [1], the risk of leakage is gone. So I am looking forward to your options about this patch. As many functions start with same instructions like 'stp fp, lr, [sp, #imm]' or 'paciasp'. So I think this patch could avoid unnecessary D/I cache synchronization. [1] https://lore.kernel.org/all/20240929162047.GA12611@redhat.com/ -- BR Liao, Chang