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=-11.3 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 650EDC433DF for ; Mon, 20 Jul 2020 22:10:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 375B822B4E for ; Mon, 20 Jul 2020 22:10:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="rEffvtAR" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726907AbgGTWKu (ORCPT ); Mon, 20 Jul 2020 18:10:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42690 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726021AbgGTWKt (ORCPT ); Mon, 20 Jul 2020 18:10:49 -0400 Received: from mail-pj1-x1041.google.com (mail-pj1-x1041.google.com [IPv6:2607:f8b0:4864:20::1041]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7521CC061794; Mon, 20 Jul 2020 15:10:49 -0700 (PDT) Received: by mail-pj1-x1041.google.com with SMTP id o22so637871pjw.2; Mon, 20 Jul 2020 15:10:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=h0GEicoGZvUY4aSOetLAK7yh5EuOCMqYG/Hqy0bSab8=; b=rEffvtAR5yY0laEVInca+LKZUHy7fvvHGPywogRX7YS2qAduLQJ0l+6YVHo0eZh2+J xB8kMhyRt6fstkCPtgGeoMwCFEvHRsfx9PtG0/ZgvhduN38XzekAFIKa0oniNUvqnFru +qG/DOKHpgFgAntgCwTdaZjaY8Nx6dk606FiOtWk0hdKFfhFV7O0o8Oz9pGv6Pqon2Cd 99wrcDypHEybAOdNoNA3FhZWnbYQb6ggkFFfmQOQQIelNIIphQ4A3IqRDCeq6hGWy0zq uZAkEZqTPYeAMyDKrPTkKBPrXc6XqXor0opjNfNwor9pdTsYMleGK8hfzVkj0nbGL6bQ qopw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to:user-agent; bh=h0GEicoGZvUY4aSOetLAK7yh5EuOCMqYG/Hqy0bSab8=; b=jUwKlnXGTiMLSqx26r668fPEsCnZHc6YDDg3Rtb0DZ8tK5ozBAMSGqELE5dBrb6L25 TEGSaF+Fl/ScC3gwsIedvZD/sKuN6WZIAMxwMZ9Y/nE+xVqcohavjSvty2eZva07scQP 8GAzrJAEDKsVgRsoY5raVb+wJcZGwrWYK6h8/zVVnyAI0pehLTP0UFPclqT+yXVNFOUE s2G4ChxtI4E/w6LImxPq2OCTRAqnNfhNX9+uPxzmMr4ZuUvdQDtsrUWZxmJvmq/Ot10f RnOkglIL/UIRsXPVL9P34U8KCHt/VshT4YH/JRZFoTSwJX4c6euuL0cBRuxXZFJLEkHR Asvw== X-Gm-Message-State: AOAM5337nv7IWU/Lvz0IZpKFZ9t9n7DLu0ufRuqZhBzErbP17xxSrA/d Phk7gcoMhi0NvHi49Krd4DE= X-Google-Smtp-Source: ABdhPJyAtwghREh+cNVe4GBVZ28Uhys24HSMBEM0bwHPLTtJGq3WqPh0KHblwq+XQJwxzII+Zp5Afg== X-Received: by 2002:a17:90a:d684:: with SMTP id x4mr1458894pju.62.1595283049018; Mon, 20 Jul 2020 15:10:49 -0700 (PDT) Received: from localhost ([2600:1700:e321:62f0:329c:23ff:fee3:9d7c]) by smtp.gmail.com with ESMTPSA id e28sm17823273pfm.177.2020.07.20.15.10.47 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Mon, 20 Jul 2020 15:10:47 -0700 (PDT) Date: Mon, 20 Jul 2020 15:10:46 -0700 From: Guenter Roeck To: Christoph Hellwig Cc: Nick Hu , Greentime Hu , Vincent Chen , Paul Walmsley , Palmer Dabbelt , Andrew Morton , Linus Torvalds , linux-riscv@lists.infradead.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/6] syscalls: use uaccess_kernel in addr_limit_user_check Message-ID: <20200720221046.GA86726@roeck-us.net> References: <20200714105505.935079-1-hch@lst.de> <20200714105505.935079-2-hch@lst.de> <20200718013849.GA157764@roeck-us.net> <20200718094846.GA8593@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200718094846.GA8593@lst.de> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Jul 18, 2020 at 11:48:46AM +0200, Christoph Hellwig wrote: > On Fri, Jul 17, 2020 at 06:38:50PM -0700, Guenter Roeck wrote: > > Hi, > > > > On Tue, Jul 14, 2020 at 12:55:00PM +0200, Christoph Hellwig wrote: > > > Use the uaccess_kernel helper instead of duplicating it. > > > > > > Signed-off-by: Christoph Hellwig > > > > This patch causes a severe hiccup with my mps2-an385 boot test. > I had another look into the code. Right after this patch, I see #define uaccess_kernel() segment_eq(get_fs(), KERNEL_DS) Yet, this patch is: - if (CHECK_DATA_CORRUPTION(!segment_eq(get_fs(), USER_DS), + if (CHECK_DATA_CORRUPTION(uaccess_kernel(), So there is a negation in the condition. Indeed, the following change on top of next-20200720 fixes the problem for mps2-an385. - if (CHECK_DATA_CORRUPTION(uaccess_kernel(), + if (CHECK_DATA_CORRUPTION(!uaccess_kernel(), How does this work anywhere ? Thanks, Guenter > I guess that is a nommu config? > > Can you try this patch? > > diff --git a/arch/arm/include/asm/uaccess.h b/arch/arm/include/asm/uaccess.h > index b19c9bec1f7a63..cc7daf374a6eb6 100644 > --- a/arch/arm/include/asm/uaccess.h > +++ b/arch/arm/include/asm/uaccess.h > @@ -263,7 +263,7 @@ extern int __put_user_8(void *, unsigned long long); > */ > #define USER_DS KERNEL_DS > > -#define uaccess_kernel() (true) > +#define uaccess_kernel() (false) > #define __addr_ok(addr) ((void)(addr), 1) > #define __range_ok(addr, size) ((void)(addr), 0) > #define get_fs() (KERNEL_DS)