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=-17.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 06FA3C433DB for ; Fri, 22 Jan 2021 13:00:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C377623444 for ; Fri, 22 Jan 2021 13:00:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727381AbhAVNAQ (ORCPT ); Fri, 22 Jan 2021 08:00:16 -0500 Received: from mail.kernel.org ([198.145.29.99]:47288 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727309AbhAVM7q (ORCPT ); Fri, 22 Jan 2021 07:59:46 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 16C16230FC; Fri, 22 Jan 2021 12:59:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1611320346; bh=KOC8i4h1phIqdtjvrL9AXOG1eCZg1fJIiF3yQKhxk/w=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=XKwMLC7OELm1PbA4JHPkLogTkoeY7R76FpH0BAn7Ij2QjRx7SUJgilab19RUDzBY2 ekl0NLm2XESpjNZs48mIRcmB7L8Ye+RjI1Wj3SAAFLoI7m5rXPBAgvZZimJmmB0Nlr I8lbf5rObXUcg3OT7WUgkXnw8TWOCy6KgvjHQhQ9obeL/KDb6nXGa6dPqx7vPkN8Rj 22VOj370oOZQh5t5OQwMZWOMNk3VmbjwJWatKGkxEgdGTRSXjwx4+zLRz06Yq9i8i8 IXkwpi7O8D7aN/KibydQfqrjQJqkRjZKEAOFpm10/90zwkcNOR4+kDPmcrp3nuNSTO RSPWPXMyMKZtA== Date: Fri, 22 Jan 2021 12:58:58 +0000 From: Will Deacon To: Dmitry Safonov Cc: linux-kernel@vger.kernel.org, Dmitry Safonov <0x7f454c46@gmail.com>, Alexander Viro , Andrew Morton , Andy Lutomirski , Brian Geffon , Catalin Marinas , Dan Williams , Dave Jiang , Hugh Dickins , Ingo Molnar , "Kirill A. Shutemov" , Mike Kravetz , Minchan Kim , Russell King , Thomas Bogendoerfer , Thomas Gleixner , Vishal Verma , Vlastimil Babka , linux-aio@kvack.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 6/6] mm: Forbid splitting special mappings Message-ID: <20210122125858.GC24102@willie-the-truck> References: <20201013013416.390574-1-dima@arista.com> <20201013013416.390574-7-dima@arista.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201013013416.390574-7-dima@arista.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Tue, Oct 13, 2020 at 02:34:16AM +0100, Dmitry Safonov wrote: > Don't allow splitting of vm_special_mapping's. > It affects vdso/vvar areas. Uprobes have only one page in xol_area so > they aren't affected. > > Those restrictions were enforced by checks in .mremap() callbacks. > Restrict resizing with generic .split() callback. > > Signed-off-by: Dmitry Safonov > --- > arch/arm/kernel/vdso.c | 9 --------- > arch/arm64/kernel/vdso.c | 41 +++------------------------------------ > arch/mips/vdso/genvdso.c | 4 ---- > arch/s390/kernel/vdso.c | 11 +---------- > arch/x86/entry/vdso/vma.c | 17 ---------------- > mm/mmap.c | 12 ++++++++++++ > 6 files changed, 16 insertions(+), 78 deletions(-) For arm64: Acked-by: Will Deacon Will