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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,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 59525C6377D for ; Thu, 22 Jul 2021 13:59:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 429A661244 for ; Thu, 22 Jul 2021 13:59:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232246AbhGVNSi (ORCPT ); Thu, 22 Jul 2021 09:18:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38510 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232105AbhGVNSg (ORCPT ); Thu, 22 Jul 2021 09:18:36 -0400 Received: from sipsolutions.net (s3.sipsolutions.net [IPv6:2a01:4f8:191:4433::2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 82173C061575; Thu, 22 Jul 2021 06:59:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sipsolutions.net; s=mail; h=Content-Transfer-Encoding:MIME-Version: Content-Type:References:In-Reply-To:Date:Cc:To:From:Subject:Message-ID:Sender :Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-To: Resent-Cc:Resent-Message-ID; bh=NNcV9llPrdlEYkKe7+LBF3xFYLJpZdKYVGYe+A5Q+4I=; t=1626962351; x=1628171951; b=S42X4+0j590vY4yyWmE9Z6M2vfPMqU6ZVMC2NpDqG24s75X p0VZ8+yPU7I8uMB2QbDCZIQ7OJA8yoYCNeFdQ5UqXC/Idybgz5gps27YZ+QR3rh+AMb1OWtUbbZQm 2ssk/Dr1IEv1rXw45C4ldEf+xi0ArjFqXXHtP9O1VtD32/0BbUZzOwRxxPBwQxOCzBnlNDCypoDZv 9x0cWOUr/h0K/snr4No81FkSnb+J5iULPldNGBxi8glSLKV6+9yYyASglCaRxtYXNoa0fYMTjenpS JIUvnJ/0MIX77P07mRDjzRwlrE6v/Zn86xf+2RgfyG+F3i5gjtghrRspjZ3Pk4Cg==; Received: by sipsolutions.net with esmtpsa (TLS1.3:ECDHE_SECP256R1__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.94.2) (envelope-from ) id 1m6ZAW-0007sj-NN; Thu, 22 Jul 2021 15:57:59 +0200 Message-ID: <29adc1c164805e355b37d1d4668ebda9fb7fa872.camel@sipsolutions.net> Subject: Re: [PATCH v3 9/9] asm-generic: reverse GENERIC_{STRNCPY_FROM, STRNLEN}_USER symbols From: Johannes Berg To: Arnd Bergmann , linux-arch@vger.kernel.org Cc: 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, linux-hexagon@vger.kernel.org, linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linux-s390@vger.kernel.org, linux-snps-arc@lists.infradead.org, linux-um@lists.infradead.org, linux-xtensa@linux-xtensa.org, uclinux-h8-devel@lists.sourceforge.jp Date: Thu, 22 Jul 2021 15:57:56 +0200 In-Reply-To: <20210722124814.778059-10-arnd@kernel.org> References: <20210722124814.778059-1-arnd@kernel.org> <20210722124814.778059-10-arnd@kernel.org> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.38.4 (3.38.4-1.fc33) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-malware-bazaar: not-scanned Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > > 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. johannes