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 X-Spam-Level: X-Spam-Status: No, score=-7.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B33A7C63799 for ; Thu, 22 Jul 2021 14:02:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9C9906135B for ; Thu, 22 Jul 2021 14:02:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232240AbhGVNVY (ORCPT ); Thu, 22 Jul 2021 09:21:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:37064 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231925AbhGVNVX (ORCPT ); Thu, 22 Jul 2021 09:21:23 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 2101B6128A; Thu, 22 Jul 2021 14:01:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1626962518; bh=RmFOlaV6cy8f6I9NP3ukwHIYeNH7OwEP2FaF3KMVtFM=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=FAJNHnFo1L7vDVOiC5UpRkaDx4pid4TNdNlKZLrXeCR+FFSWM3S5SOfKHU3NBCcgi x/mbKRZuCP5sBZWLRH0QyC3jTezIcTdgPNuJkn722HgIPBdCNBSTL40ELD6XBnTs/y 1ZjVc7/Oq6j6jnQceie9Da0nul67XzXgLTZj2GmS3GDKLgwa7unHRN+n/B9s9iygfR gHGpjMzt0PFMYc3FrdBQF57NRhZXStlwHBGM47znuAnJK24bV4xEdnVgYTuM2O9Q9l cPPu7vcO0sT3ruel4hr978oxdF6OQbMo96r5w0ZtG5V3ocVCUbJ85hWT9lKdyIIY8o uhvj1YnfZDenA== Received: by mail-wr1-f42.google.com with SMTP id c15so6078609wrs.5; Thu, 22 Jul 2021 07:01:58 -0700 (PDT) X-Gm-Message-State: AOAM531dTsLBoyXY46jXwvz5czFANrce3/1ohs2mSfcIRgYYh2V2YWfX anOKN93+gKWUubFcGJ5kbFbKeL8DFH7/BeQeBE0= X-Google-Smtp-Source: ABdhPJwKEmOULt07FXrSo8OqydMhW6AyGqw3Y4ZL7MXTHJEhxOwFXM5UwB4aLTKy+iIlhqkT2HtTedqadCpqLwCc8hw= X-Received: by 2002:a5d:438c:: with SMTP id i12mr49853wrq.99.1626962516717; Thu, 22 Jul 2021 07:01:56 -0700 (PDT) MIME-Version: 1.0 References: <20210722124814.778059-1-arnd@kernel.org> <20210722124814.778059-10-arnd@kernel.org> <29adc1c164805e355b37d1d4668ebda9fb7fa872.camel@sipsolutions.net> In-Reply-To: <29adc1c164805e355b37d1d4668ebda9fb7fa872.camel@sipsolutions.net> From: Arnd Bergmann Date: Thu, 22 Jul 2021 16:01:39 +0200 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v3 9/9] asm-generic: reverse GENERIC_{STRNCPY_FROM, STRNLEN}_USER symbols To: Johannes Berg Cc: linux-arch , Arnd Bergmann , "James E.J. Bottomley" , Al Viro , Anton Ivanov , Brian Cain , Chris Zankel , Christian Borntraeger , Christoph Hellwig , Guo Ren , Heiko Carstens , Helge Deller , Jeff Dike , Linus Walleij , Max Filippov , Michal Simek , Richard Weinberger , Thomas Bogendoerfer , Vasily Gorbik , Vineet Gupta , Yoshinori Sato , linux-csky@vger.kernel.org, "open list:QUALCOMM HEXAGON..." , linux-ia64@vger.kernel.org, Linux Kernel Mailing List , "open list:BROADCOM NVRAM DRIVER" , Parisc List , linux-s390 , "open list:SYNOPSYS ARC ARCHITECTURE" , linux-um , "open list:TENSILICA XTENSA PORT (xtensa)" , "moderated list:H8/300 ARCHITECTURE" Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org On Thu, Jul 22, 2021 at 3:57 PM Johannes Berg wrote: > > > > > The remaining architectures at the moment are: ia64, mips, parisc, > > s390, um and xtensa. We should probably convert these as well, but > > I'm not sure it makes sense to convert um, the implementation uses > strncpy(), and that should use the libc implementation, which is tuned > for the actual hardware that the binary is running on, so performance > wise that might be better. > > OTOH, maybe this is all in the noise given the huge syscall overhead in > um, so maybe unifying it would make more sense. Right, makes sense. I suppose if we end up converting mips and s390, we should just do arch/um and the others as well for consistency, even if that adds some overhead. Arnd