From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kees Cook Subject: Re: [PATCH v5 15/30] arm64/sve: Signal handling support Date: Mon, 11 Dec 2017 11:23:09 -0800 Message-ID: References: <1509465082-30427-1-git-send-email-Dave.Martin@arm.com> <1509465082-30427-16-git-send-email-Dave.Martin@arm.com> <20171207104948.GE31900@arm.com> <20171211140720.GE2141@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Return-path: Received: from mail-ua0-f195.google.com ([209.85.217.195]:46083 "EHLO mail-ua0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752160AbdLKTXK (ORCPT ); Mon, 11 Dec 2017 14:23:10 -0500 Received: by mail-ua0-f195.google.com with SMTP id t24so12733760uaa.13 for ; Mon, 11 Dec 2017 11:23:10 -0800 (PST) In-Reply-To: <20171211140720.GE2141@arm.com> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Will Deacon Cc: Dave Martin , linux-arm-kernel@lists.infradead.org, linux-arch , Okamoto Takayuki , libc-alpha , Ard Biesheuvel , Szabolcs Nagy , Catalin Marinas , =?UTF-8?B?QWxleCBCZW5uw6ll?= , kvmarm@lists.cs.columbia.edu On Mon, Dec 11, 2017 at 6:07 AM, Will Deacon wrote: > On Thu, Dec 07, 2017 at 10:50:38AM -0800, Kees Cook wrote: >> My question is mainly: why not just use copy_*() everywhere instead? >> Having these things so spread out makes it fragile, and there's very >> little performance benefit from using __copy_*() over copy_*(). > > I think that's more of a general question. Why not just remove the __ > versions from the kernel entirely if they're not worth the perf? That has been something Linus has strongly suggested in the past, so I've kind of been looking for easy places to drop the __copy_* versions. :) -Kees -- Kees Cook Pixel Security From mboxrd@z Thu Jan 1 00:00:00 1970 From: keescook@chromium.org (Kees Cook) Date: Mon, 11 Dec 2017 11:23:09 -0800 Subject: [PATCH v5 15/30] arm64/sve: Signal handling support In-Reply-To: <20171211140720.GE2141@arm.com> References: <1509465082-30427-1-git-send-email-Dave.Martin@arm.com> <1509465082-30427-16-git-send-email-Dave.Martin@arm.com> <20171207104948.GE31900@arm.com> <20171211140720.GE2141@arm.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Mon, Dec 11, 2017 at 6:07 AM, Will Deacon wrote: > On Thu, Dec 07, 2017 at 10:50:38AM -0800, Kees Cook wrote: >> My question is mainly: why not just use copy_*() everywhere instead? >> Having these things so spread out makes it fragile, and there's very >> little performance benefit from using __copy_*() over copy_*(). > > I think that's more of a general question. Why not just remove the __ > versions from the kernel entirely if they're not worth the perf? That has been something Linus has strongly suggested in the past, so I've kind of been looking for easy places to drop the __copy_* versions. :) -Kees -- Kees Cook Pixel Security