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=-1.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 1A528C433E2 for ; Wed, 13 May 2020 19:37:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C0C9A206CC for ; Wed, 13 May 2020 19:37:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589398655; bh=VWs4NpfAEV+Wf9gSeX0e5o0koUyBavjyGOUsk1rJZSE=; h=References:In-Reply-To:From:Date:Subject:To:Cc:List-ID:From; b=XBBpo7c/r9zmzfGQ86OgvaQNeJl+58VbJ4/JGjB8s2LmDgsw06T7ndJUosaYcMt5b AaFUuKqDoPiDTqf0lgnGIEJASy0B5psOrBcuS47shAgLBSWtRtcnhYVEfhXf07FciL JJy8kGc6W4QxEFkeE73qrRJv6pAssDHzJfWDsFRY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390726AbgEMThe (ORCPT ); Wed, 13 May 2020 15:37:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56470 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S2390623AbgEMThd (ORCPT ); Wed, 13 May 2020 15:37:33 -0400 Received: from mail-lf1-x141.google.com (mail-lf1-x141.google.com [IPv6:2a00:1450:4864:20::141]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 30E1DC061A0E for ; Wed, 13 May 2020 12:37:32 -0700 (PDT) Received: by mail-lf1-x141.google.com with SMTP id 188so511939lfa.10 for ; Wed, 13 May 2020 12:37:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=5FRYECFHiQr3Nfb1uzqLNFih4Bcng0OOjZJ5V5m4DAs=; b=ZjLEDdjhfQ+ZsfStprzo3boptGtjEB8xMJMPV9hfgVHHrrYSleH8mLbHC8Rk2rWQqc NnCj3BIzoVOHPTIgSoBKM0vWlfW3SuT0UoYyIfcumKGQE/4wsqoLb39sPYuJ5/AuOelG tGQKJ8l9ywdlX+FMm4CTzGEq2pztEwBhTbMlg= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=5FRYECFHiQr3Nfb1uzqLNFih4Bcng0OOjZJ5V5m4DAs=; b=b69G/Xd/4OgwPK4xotQ+lF7ckPKoebtlsNX/RK1xx+XiWdu6q0Fihl2wrzL3f7yYEi Vy6XS4gULnoIj5UoEQ4wgulJltIUm7u8gYLegrY6BfoqtYl6VxIyiOrpsbpdL86AjcBr /Sp0AzC/zXiEQ7C46a3/Ja6wF9D+1x1mE4bXmGQcOgJ8U9py1lA3eLs+MAmXrsjQdMNi FkkXdPAxErhpmppNaoJedu6StsdF5Lk8efcF3ocgo6Q3ELFoIyzApFrmQ893YCQuEgfr cInbszaRq8jYC6amyxigLhL1lfw5XKaat4Xfsg50CPo8LcdmKXo/t7cTbIZ/nfhYHBQI LJcg== X-Gm-Message-State: AOAM533UbD6DCYeXk/9ttzm6tHCE+YYzq7LdAUGzuwq6YAuvYHkcm7KD GpjHqFxpJ5acxvEsXyCqdVhSS8aXzIU= X-Google-Smtp-Source: ABdhPJxITX82Gs+F7FLTKT+ypYtZWWOhyisq5m6V4cCLakT+hiKX5Mwg3kGrYXWRKa1cO9H5xXyy5w== X-Received: by 2002:ac2:5212:: with SMTP id a18mr680991lfl.83.1589398650086; Wed, 13 May 2020 12:37:30 -0700 (PDT) Received: from mail-lf1-f53.google.com (mail-lf1-f53.google.com. [209.85.167.53]) by smtp.gmail.com with ESMTPSA id n2sm308418lfl.53.2020.05.13.12.37.28 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 13 May 2020 12:37:29 -0700 (PDT) Received: by mail-lf1-f53.google.com with SMTP id c21so548244lfb.3 for ; Wed, 13 May 2020 12:37:28 -0700 (PDT) X-Received: by 2002:ac2:4da1:: with SMTP id h1mr686949lfe.152.1589398648496; Wed, 13 May 2020 12:37:28 -0700 (PDT) MIME-Version: 1.0 References: <20200513160038.2482415-1-hch@lst.de> In-Reply-To: <20200513160038.2482415-1-hch@lst.de> From: Linus Torvalds Date: Wed, 13 May 2020 12:37:12 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: clean up and streamline probe_kernel_* and friends v2 To: Christoph Hellwig Cc: "the arch/x86 maintainers" , Alexei Starovoitov , Daniel Borkmann , Masami Hiramatsu , Andrew Morton , linux-parisc@vger.kernel.org, linux-um , Netdev , bpf@vger.kernel.org, Linux-MM , Linux Kernel Mailing List Content-Type: text/plain; charset="UTF-8" Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Wed, May 13, 2020 at 9:00 AM Christoph Hellwig wrote: > > this series start cleaning up the safe kernel and user memory probing > helpers in mm/maccess.c, and then allows architectures to implement > the kernel probing without overriding the address space limit and > temporarily allowing access to user memory. It then switches x86 > over to this new mechanism by reusing the unsafe_* uaccess logic. Ok, I think I found a bug, and I had one more suggestion, but other than the two emails I sent this all looks like an improvement to me. Linus