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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1C49DC19F2D for ; Tue, 9 Aug 2022 20:21:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345290AbiHIUV3 (ORCPT ); Tue, 9 Aug 2022 16:21:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44860 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345844AbiHIUU6 (ORCPT ); Tue, 9 Aug 2022 16:20:58 -0400 Received: from mail-ed1-x529.google.com (mail-ed1-x529.google.com [IPv6:2a00:1450:4864:20::529]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C1224193F2 for ; Tue, 9 Aug 2022 13:20:54 -0700 (PDT) Received: by mail-ed1-x529.google.com with SMTP id s11so16490256edd.13 for ; Tue, 09 Aug 2022 13:20:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=google; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc; bh=DGKHHAUwuZfCazjxcNKKHUT7rJIi8ll9zTOb4y7hCUc=; b=WEfpeEZLySvke8oWrURAvNB0cuhg5p2fhHNFSr8Ptu4Bkc8DH9B5yKXXkiA0f8ZSUv Wk+tTMhRbTpst7yfa9aNELS/+G+R2Y1Y3t1e8NW7tW/W29tb/gDh8ah0vHJT8w/US+Z4 v7PoDdCm6NLn1YJYubR0e9eymGioz29VRHsSE= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc; bh=DGKHHAUwuZfCazjxcNKKHUT7rJIi8ll9zTOb4y7hCUc=; b=pFUxNF6KHCoIp5X7CAYhn9P+hNqKvUN/IYyFR5ytZTLi4ybhBqv5nX/bo+rJhDDqyM pOCIMlAdZ1KvzZPXTaxY8fXfUZ4piA2HYQrGo1QEtUrYc9sNZIM3k7LkE63uEHW8GzIi 4rEJVB/PS/NBg135tD+W7At1RWjJZHYaaVvHpBJr4XFzLSrcCD2AUx5UXnk8M1tM+w1k T49/A6k7Kj8dfy8zMZyu5g19+fA8X9NtQMG06pnLLPA4fX0lGDVVegWr69rRcs0lJiQY FoSu2tNpYMCmdCZOYSzPCAgxT3g0XMBP/59lzXaU1WuH+Eoh7uUwPKUFwnEPu1DUl2xQ A8uw== X-Gm-Message-State: ACgBeo1N+c+qDaLVUnkUGeoQ/l0KK6DbWFsR1drzakPNKEFzEa8hNn7h isOPbTVWZUL/cag2QCq6qonlf/xxfdXAh2GZ+0E= X-Google-Smtp-Source: AA6agR5Y6wVYgHL588850zPI8L7NdpCC6nJ0vVEZ7PCr/AW5aUbpx6RX7OE2et7HIIWxDGQdtwT1PA== X-Received: by 2002:a05:6402:1703:b0:43c:c03a:db3d with SMTP id y3-20020a056402170300b0043cc03adb3dmr23288404edu.384.1660076453110; Tue, 09 Aug 2022 13:20:53 -0700 (PDT) Received: from mail-wr1-f52.google.com (mail-wr1-f52.google.com. [209.85.221.52]) by smtp.gmail.com with ESMTPSA id hx22-20020a170906847600b0070efa110afcsm1491885ejc.83.2022.08.09.13.20.52 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 09 Aug 2022 13:20:52 -0700 (PDT) Received: by mail-wr1-f52.google.com with SMTP id z12so15510885wrs.9 for ; Tue, 09 Aug 2022 13:20:52 -0700 (PDT) X-Received: by 2002:a5d:6248:0:b0:222:cd3b:94c8 with SMTP id m8-20020a5d6248000000b00222cd3b94c8mr7137394wrv.97.1660076452117; Tue, 09 Aug 2022 13:20:52 -0700 (PDT) MIME-Version: 1.0 References: <20220808073232.8808-1-david@redhat.com> <91e18a2f-c93d-00b8-7c1b-6d8493c3b2d5@redhat.com> In-Reply-To: From: Linus Torvalds Date: Tue, 9 Aug 2022 13:20:36 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v1] mm/gup: fix FOLL_FORCE COW security issue and remove FOLL_COW To: David Hildenbrand Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, stable@vger.kernel.org, Andrew Morton , Greg Kroah-Hartman , Axel Rasmussen , Peter Xu , Hugh Dickins , Andrea Arcangeli , Matthew Wilcox , Vlastimil Babka , John Hubbard , Jason Gunthorpe Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Aug 9, 2022 at 1:14 PM Linus Torvalds wrote: > > But as there are two bits, I'm sure somebody ends up touching one and > not the other. Ugh. The nommu code certainly does odd things here. That just looks wrong. And the hugetlb code does something horrible too, but never *sets* it, so it looks like some odd subset of VM_SHARED. Linus