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 Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D62DCC433F5 for ; Mon, 14 Feb 2022 20:00:52 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4JyFTH0b0Xz3cYg for ; Tue, 15 Feb 2022 07:00:51 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=none (no SPF record) smtp.mailfrom=lst.de (client-ip=213.95.11.211; helo=verein.lst.de; envelope-from=hch@lst.de; receiver=) Received: from verein.lst.de (verein.lst.de [213.95.11.211]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4JyFSk5y44z2yLP for ; Tue, 15 Feb 2022 07:00:21 +1100 (AEDT) Received: by verein.lst.de (Postfix, from userid 2407) id 2A25C68AA6; Mon, 14 Feb 2022 21:00:11 +0100 (CET) Date: Mon, 14 Feb 2022 21:00:11 +0100 From: Christoph Hellwig To: Arnd Bergmann Subject: Re: [PATCH 04/14] x86: use more conventional access_ok() definition Message-ID: <20220214200011.GA3786@lst.de> References: <20220214163452.1568807-1-arnd@kernel.org> <20220214163452.1568807-5-arnd@kernel.org>

MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Rich Felker , linux-ia64@vger.kernel.org, Linux-sh list , Peter Zijlstra , "open list:BROADCOM NVRAM DRIVER" , Max Filippov , Guo Ren , sparclinux , linux-riscv , Will Deacon , Ard Biesheuvel , linux-arch , linux-s390 , Brian Cain , "open list:QUALCOMM HEXAGON..." , Helge Deller , the arch/x86 maintainers , Russell King - ARM Linux , linux-csky@vger.kernel.org, Christoph Hellwig , Christoph Hellwig , Ingo Molnar , Geert Uytterhoeven , "open list:SYNOPSYS ARC ARCHITECTURE" , "open list:TENSILICA XTENSA PORT \(xtensa\)" , Arnd Bergmann , Heiko Carstens , linux-um , linuxppc-dev , Richard Weinberger , linux-m68k , Openrisc , Greentime Hu , Stafford Horne , Linux ARM , Michal Simek , Thomas Bogendoerfer , Nick Hu , Parisc List , Linux-MM , Linux API , Linux Kernel Mailing List , Dinh Nguyen , "Eric W . Biederman" , alpha , Andrew Morton , Linus Torvalds , David Miller , Al Viro Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Mon, Feb 14, 2022 at 08:45:52PM +0100, Arnd Bergmann wrote: > As Al pointed out, they turned out to be necessary on sparc64, but the only > definitions are on sparc64 and x86, so it's possible that they serve a similar > purpose here, in which case changing the limit from TASK_SIZE to > TASK_SIZE_MAX is probably wrong as well. > > So either I need to revert the original definition as I did on sparc64, or > they can be removed completely. Hopefully Al or the x86 maintainers > can clarify. Looking at the x86 users I think: - valid_user_frame should go away and the caller should use get_user instead of __get_user - the one in copy_code can just go away, as there is another check in copy_from_user_nmi - copy_stack_frame should just use access_ok - as does copy_from_user_nmi but yes, having someone who actually knows this code look over it would be very helpful.