Received: by 2002:a25:683:0:0:0:0:0 with SMTP id 125csp242161ybg; Mon, 8 Jun 2020 22:32:19 -0700 (PDT) X-Google-Smtp-Source: ABdhPJwFLo+zsD/K7YqIiVlOzo9bvSzWzq8a6zOOaAnS2LXfdGjHGGD/qYzsqAOGruKHj8hu59y+ X-Received: by 2002:a50:9b16:: with SMTP id o22mr24651998edi.130.1591680739776; Mon, 08 Jun 2020 22:32:19 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1591680739; cv=none; d=google.com; s=arc-20160816; b=Tljrpwlw1jp3mNQn5hNgLD8jfivY9+05akRGj1rwzrjzuembP/7+8zqo6nJvW/Exof 6CzRTqIzJtHiMT+21AQx+Xw9czFNuxf7bjSuz5rOr+/c47muUNFrMViJY3EY/gQdscdp 6k6ba1ytyfu1hXncCOMyNn+vYoml3GrjpQk5A82sra9MSPuOQJ+Jd6FTGC613qWOIh8x XXrTHEgyQ3W/Z3WMldyvMnQcnBqATa7fcR9ny3/Sg0nCF/5UxR1YVqKHjJpPl9lN9tN7 szjTWfPkfBrld3e1doV84+/Jh8YQJ0B7d70PsPZPiepWdGbYQAkmdmF5gYA1obTQcdZe cnyg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:date:message-id:subject:references :in-reply-to:cc:to:from; bh=4SlwSg8P8qcIjLWKhmJuxoQPIcFnRgh9CYpVgWDF8s4=; b=UuXw1itQsH6nAdYVEjLlPPUakqz+YNuau/kiEZzV9VwB0IuqE4RYoqjw8u1IVXGflh Javx0eRdGope86RD9etJ2ZUuetw7IRiShmukbUCBORhCJ6/LIy0S+DTYYAzTbyTLktFZ Adg/8Kq8jdJDZ+z67+VV1MCkP5jwGVbC9ekScZcl34cdc2PC4a8530duQl+jmQQR2dPs ryC3V9CJh2y7mxlYHdW4dG9aNnt1Ut1Vrpm8C0CQVf1LigKEBQe7xG8fwGySnV0ykM3B nMQMDLMKTw4fyLyQywL2/1rFhXIhZGp3ljo73jw5fvAcR68MSICNrz1Esoa13pvOiN4Q hDdQ== ARC-Authentication-Results: i=1; mx.google.com; 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 y18si10037687ejm.315.2020.06.08.22.31.57; Mon, 08 Jun 2020 22:32:19 -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; 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 S1727812AbgFIF2t (ORCPT + 99 others); Tue, 9 Jun 2020 01:28:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39784 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727111AbgFIF2m (ORCPT ); Tue, 9 Jun 2020 01:28:42 -0400 Received: from ozlabs.org (ozlabs.org [IPv6:2401:3900:2:1::2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E730CC03E969 for ; Mon, 8 Jun 2020 22:28:41 -0700 (PDT) Received: by ozlabs.org (Postfix, from userid 1034) id 49gzDm3Vqgz9sTN; Tue, 9 Jun 2020 15:28:40 +1000 (AEST) From: Michael Ellerman To: Christophe Leroy , Paul Mackerras , Benjamin Herrenschmidt , Michael Ellerman Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org In-Reply-To: <154a99399317b096ac1f04827b9f8d7a9179ddc1.1586962586.git.christophe.leroy@c-s.fr> References: <154a99399317b096ac1f04827b9f8d7a9179ddc1.1586962586.git.christophe.leroy@c-s.fr> Subject: Re: [PATCH] powerpc/uaccess: Don't set KUAP by default on book3s/32 Message-Id: <159168035057.1381411.13783600194244224122.b4-ty@ellerman.id.au> Date: Tue, 9 Jun 2020 15:28:40 +1000 (AEST) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 15 Apr 2020 14:57:09 +0000 (UTC), Christophe Leroy wrote: > On book3s/32, KUAP is an heavy process as it requires to > determine which segments are impacted and unlock/lock > each of them. > > And since the implementation of user_access_begin/end, it > is even worth for the time being because unlike __get_user(), > user_access_begin doesn't make difference between read and write > and unlocks access also for read allthought that's unneeded > on book3s/32. > > [...] Applied to powerpc/next. [1/1] powerpc/uaccess: Don't set KUAP by default on book3s/32 https://git.kernel.org/powerpc/c/547e687b2981a115814962506068873d24983af7 cheers