Received: by 2002:a25:1985:0:0:0:0:0 with SMTP id 127csp1090494ybz; Fri, 1 May 2020 14:21:19 -0700 (PDT) X-Google-Smtp-Source: APiQypIAiJJAf8SzlDTOO/ykK0aBsQ1mL9ZaeUvyN6AdnA8N7eyuzyoJy6W8gi7t5XosIHZJgp4x X-Received: by 2002:a17:906:d9cf:: with SMTP id qk15mr5418391ejb.55.1588368079514; Fri, 01 May 2020 14:21:19 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1588368079; cv=none; d=google.com; s=arc-20160816; b=mM7WLG5MSlG86wNzDYFKVUEvBfQLdZ076mgCEdCp7cYRBvJPJ3Rkilgp7jmw2JQ36k D0g9KbmdgRYTo5syrMulYZGpnXkLh92MH615cVffBNse2fN1Gkg0orWWjR7B0P+x7ygs V/HPgGd1Sk3Qw76D0bfyvYZsX6KriQcvzbLPoYhr1l2fhYkkxlKKtPacd5ib0ZHcFbvx 4Jx7XOmVdKGFHQ+MjrzRchR2lkiAxt0g6UAd6M/68bZD1F9nqnBSmMUV4hqiC/fzoFCU b1YBRtO0GU3EUVPyHjdE1UDJGjc0G72dSi+ztG8Sw4JWg/EpO7oT8eZXmwIjXgbRx6XD 66sA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding:mime-version :references:in-reply-to:message-id:subject:cc:to:from:date :dkim-signature; bh=Gxdn/ANQaCe8HxCn4SX7/xQfunxeO2QiKSi7vP4a114=; b=rZhpk2tD7WlkBcjEh/WPBQ+YTS/rr7NgFrBUZ0u/ZEjAtpwm+Wa0IQbQTJjDpuwFY7 8ZHthcF6GebOy2/knkFWeGqFovMJp2CXpjkph/LZ7p7rIFQ7zXdqaFfpZMiXLrED0zLC 24XoIRCmab4UjAkv9xUZyigIdY4qOyrWBsg4+h5+d2zlCITrdTmdKi0oF6WwS8QD25b3 B1ad6bB+x4Q8QIWgoaIomwUbScLtAQNud6eO4GRwIC7lxYlZc7KLWy4p54+TTDCzAiaL KAUNl1mtuutRJhZdBpLrDHiCXWFM8xHqrNkxyey4X5tm9fvP4RrIHhY/yKSWXPOio6rP bmtw== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=1OURwhfW; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id cw21si2421373ejb.158.2020.05.01.14.20.55; Fri, 01 May 2020 14:21:19 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=1OURwhfW; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726415AbgEAVTF (ORCPT + 99 others); Fri, 1 May 2020 17:19:05 -0400 Received: from mail.kernel.org ([198.145.29.99]:39232 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726045AbgEAVTF (ORCPT ); Fri, 1 May 2020 17:19:05 -0400 Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 88E9E20787; Fri, 1 May 2020 21:19:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588367945; bh=eS4UFrsPzGu4rvp9KfgUzgHF9eFBoLTYHJ7BQe382wk=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=1OURwhfWhQ712LzjrmsRXv/qnPOWXnqXvqPjKnaoB1zOxQmDB2UaYfMMzEs4gZ8MP Bt4ZnmD5d8sdd3IzGK5ZtRkNTg7zhWibaEwEUoFROYrODSFbELcTnYf+g936Wdu8vn 3ag5Fotuv7+d67bdifx+GdSZSf/mA6VoHUab1ekw= Date: Fri, 1 May 2020 14:19:03 -0700 From: Andrew Morton To: Christoph Hellwig Cc: Alexander Viro , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] exec: open code copy_string_kernel Message-Id: <20200501141903.5f7b1f81fdd38ae372d91f0e@linux-foundation.org> In-Reply-To: <20200501104105.2621149-3-hch@lst.de> References: <20200501104105.2621149-1-hch@lst.de> <20200501104105.2621149-3-hch@lst.de> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 1 May 2020 12:41:05 +0200 Christoph Hellwig wrote: > Currently copy_string_kernel is just a wrapper around copy_strings that > simplifies the calling conventions and uses set_fs to allow passing a > kernel pointer. But due to the fact the we only need to handle a single > kernel argument pointer, the logic can be sigificantly simplified while > getting rid of the set_fs. > I don't get why this is better? copy_strings() is still there and won't be going away - what's wrong with simply reusing it in this fashion? I guess set_fs() is a bit hacky, but there's the benefit of not having to maintain two largely similar bits of code?