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=-1.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,T_DKIMWL_WL_HIGH autolearn=ham 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 B3255C04AB5 for ; Mon, 3 Jun 2019 16:09:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 872A827440 for ; Mon, 3 Jun 2019 16:09:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559578142; bh=FVVoo4+poeWonnJJM6ojm7XX1p60P1ky76MuzIox/T4=; h=References:In-Reply-To:From:Date:Subject:To:Cc:List-ID:From; b=k18X1b9pBk7tT//vO56Sp9y5P78356EwdCXxShlYUvGOG6E84TOD2lKkplk7ljN6t ltzNG2qf5x7Vyb7zwk0W4skwHSu6w59UVoDKFU4Ie/kO8czI8Pe1yghoaL10U5W36G lClWFpUKQ1fSrWu/juVTOpgMy2SOW5bDDUW2UwLA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728068AbfFCQJC (ORCPT ); Mon, 3 Jun 2019 12:09:02 -0400 Received: from mail-lj1-f194.google.com ([209.85.208.194]:43123 "EHLO mail-lj1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727501AbfFCQJC (ORCPT ); Mon, 3 Jun 2019 12:09:02 -0400 Received: by mail-lj1-f194.google.com with SMTP id 16so3182701ljv.10 for ; Mon, 03 Jun 2019 09:09:00 -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=lgsfrWNkeAwXitTJcoIdmm+S5jV0yGJC2wH7GAyc/RM=; b=WCXqjpyK9CxskKR1Rsa2JsUVjNbLjTBCO3DKbpdiCOAgDG3/x4OwA5zT3oR9AF+TAb KoxRzjysV3/yPddUMg57RzzWz8pj3wl00UXp/zI8qmqY5Pxb0GSO0BkOluklf9MnQYLn o8mf30F5cjoqsx0tY+OcCybKIrmRF+OMKq7aY= 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=lgsfrWNkeAwXitTJcoIdmm+S5jV0yGJC2wH7GAyc/RM=; b=pJOcXcjwFw1vVySkZ3lYGRLAHPdwDM2NxsB6F1V8N9yLcbBF8f5wSZCIoduKmmSDUd mTfKSiWNULHxnE99IiyBEj3KeEfBA/I7xt31isfvt6ZhV5KGdSgwuGgG/vcU4vjmG/A0 2CFTPeBlg1JeOKIg1j7bPtrRnzJBd1BibRyv5fa4U3nypP71legaLUqDL+9DxYrcGxxt nT/010Likprfk0mrnqToRS7eTE48RJan93xuvPhKkOPDlENadPaK6rRopQK4lXJ3Vg1D iXI5lfcNYvLSri3DMV9c3peHmX1JOnw/mXOEp7rrWLFrfwUDEwdsWohF8KkkbiRu8qr1 uFgg== X-Gm-Message-State: APjAAAU+diqzPsAvZsUhTsoONNXQC3bRm87KL5rX2fu91tjsz9Rn++mn KILzFDp5QFZAY8c6rVcyuhLcwP/dUpI= X-Google-Smtp-Source: APXvYqxEGOcK1zdO1CWoUJUJZw5xyIT2BPUtgf/Zu8/Py3QlU8t2RS55UN5RsL7CFlCNcL8Bii4tPg== X-Received: by 2002:a2e:81c4:: with SMTP id s4mr1706895ljg.182.1559578140173; Mon, 03 Jun 2019 09:09:00 -0700 (PDT) Received: from mail-lj1-f171.google.com (mail-lj1-f171.google.com. [209.85.208.171]) by smtp.gmail.com with ESMTPSA id i23sm512111ljb.7.2019.06.03.09.08.59 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 03 Jun 2019 09:09:00 -0700 (PDT) Received: by mail-lj1-f171.google.com with SMTP id 16so3182633ljv.10 for ; Mon, 03 Jun 2019 09:08:59 -0700 (PDT) X-Received: by 2002:a2e:4246:: with SMTP id p67mr14377820lja.44.1559578139147; Mon, 03 Jun 2019 09:08:59 -0700 (PDT) MIME-Version: 1.0 References: <20190601074959.14036-1-hch@lst.de> <20190601074959.14036-4-hch@lst.de> <20190603074121.GA22920@lst.de> In-Reply-To: <20190603074121.GA22920@lst.de> From: Linus Torvalds Date: Mon, 3 Jun 2019 09:08:43 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH 03/16] mm: simplify gup_fast_permitted To: Christoph Hellwig Cc: Paul Burton , James Hogan , Yoshinori Sato , Rich Felker , "David S. Miller" , Nicholas Piggin , Khalid Aziz , Andrey Konovalov , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , linux-mips@vger.kernel.org, Linux-sh list , sparclinux@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, Linux-MM , "the arch/x86 maintainers" , Linux List Kernel Mailing Content-Type: text/plain; charset="UTF-8" Sender: linux-mips-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org On Mon, Jun 3, 2019 at 12:41 AM Christoph Hellwig wrote: > > I only removed a duplicate of it. I don't see any remaining cases. > The full (old) code in get_user_pages_fast() looks like this: > > if (nr_pages <= 0) > return 0; > > if (unlikely(!access_ok((void __user *)start, len))) > return -EFAULT; > > if (gup_fast_permitted(start, nr_pages)) { Yes, and that code was correct. The new code has no test at all for "nr_pages == 0", afaik. Linus