From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4927AF9E8 for ; Thu, 24 Jul 2025 21:32:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753392757; cv=none; b=ciCbA9B1v+StecmXCxnQs3lF3zlUu50kkgHQE0IAK78uX3QmuSBcF6UJk7Jb7q1dYrZZRUCSGWTB0t7m/njyKNqazwkWDRYJbgQkFtQKviR8MCxI2m4HhxXowVzWEoWvHi8HgfEsJZkN0P50s/LCGgQ7Za951wu2T9a5g0B0t58= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753392757; c=relaxed/simple; bh=2cGQ56dbsxK1druA/XiJMH+oxCfrEx6kK6FcnWfJKjw=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=naW8ZNI4X/REl75ZjqJPeHFs87VAbNZ5poJQS7bhWELKWNlV0nxu4WdSxgGGiFnDBGWSDkJOEjRiZlkcTHAqNJeA0ABaqaEbZO0/2hkgMrYPHkCTqGikzlD4/NFMch7Y8mVwMUGJdm8Y9CLksO9iIZDl+xJgUStGyd4e5AC1GtI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=SQcUy6ux; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="SQcUy6ux" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1753392754; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=azr2brsZ6Ua8mVeqP54+Ze96cYo9iUAaUmwXzQQMwtE=; b=SQcUy6uxLin3kYmEdEefT72XhVJCYwGsjYpdYzHOW1358NQhq3cI4ysq93b8NzYO4Dhz6C As/8B4ULfuhQeMc91sga/FGJnbHn0D1xrdQavHrcMjbFPBQbvIARCFLgrtMMTr3O79qGzl 2rbjdkr5hRse+3UU/3atArdYcuWplOA= Received: from mail-wr1-f70.google.com (mail-wr1-f70.google.com [209.85.221.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-168-M4bhmrB7P3qQZ92op6cQxg-1; Thu, 24 Jul 2025 17:32:32 -0400 X-MC-Unique: M4bhmrB7P3qQZ92op6cQxg-1 X-Mimecast-MFC-AGG-ID: M4bhmrB7P3qQZ92op6cQxg_1753392751 Received: by mail-wr1-f70.google.com with SMTP id ffacd0b85a97d-3a4eb6fcd88so965364f8f.1 for ; Thu, 24 Jul 2025 14:32:32 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1753392751; x=1753997551; h=content-transfer-encoding:in-reply-to:organization:autocrypt :content-language:from:references:cc:to:subject:user-agent :mime-version:date:message-id:x-gm-message-state:from:to:cc:subject :date:message-id:reply-to; bh=azr2brsZ6Ua8mVeqP54+Ze96cYo9iUAaUmwXzQQMwtE=; b=r9r6GG/8l/lpdYeNc+ZsdC9Apdw186I0Jd1I9Oc3u3noVhYE2w/mBMUBjbBzwWdx2R tgNRzreWQOjHceAISvDL3I6UzyaHvyz7YcLjZvSqNaIZ3voRPA5ZW6rBWk7sGIUnNSak G2cZAkRsrV24F1pB6hxmrCM0XRtNhBoUZen8OThGVFwiEIMtcDw13efWCj+cNdBtNOls HJG0G+owkHd4RIi1ywZIiBEnwXRI344rjTJI1W8IgKIe/dtgJn9bSH5zWcfN8ZNFWa5h vv+ze5D5nPGuTvQ/u0Uw0dfAdZpAOh5Kl/EKkJDlQqkz4+Q2cyRHiPprrbp53Pozl5Oc 6YRw== X-Forwarded-Encrypted: i=1; AJvYcCX2sBVDzAn/BgWmbD5GqqdQKtiea2gCLE7kFWXenY1tzjBIdckfJIjAKGGzthaLT1KaRdmaRvrCT4SfJYY=@vger.kernel.org X-Gm-Message-State: AOJu0Yw/UYBZc99GNLWJq4+zfEhXD9xPFBPyD/yG2pupOWm+JxTtatuY 8BJ+2zb+81Be/lEPndfY9M+TsVaeQvnvjtKCMjkiXwZyCDcA4mnHX75d3lVMyIGbWOg3iSFRywL D5VIegJbc+jGBI6/+T6a5ASXSTEpzmk1wqQxSLtdNeAOwn38QG334iCDTsPrtrFKbFg== X-Gm-Gg: ASbGncvHNaq5vzzkEfLxWwB09UO3MnOUoq2PZRHDxArMOJ+YVfaVPmgMI6csLSSY4YH EfL5KhFarAz4VOagC+hVXSlkW47Ai0BmsJi+trtSq2BM91tKDGvuOn0VtxFHn7PzCBQweW8TLPe EkDLz74EJTGRdadsMgU/7AXhEI5RKX6KXs3NUWxn29Xr6UyHZ3pKJ3/F8PeGZuoIHSl/QViMq6N e5k8r6iuxmo+xV1y2T0twoewvAQoXX0c2MT7FO/8Bp9X1jR5Ub3QwP+jmgkBUDXcKOv846b2L04 JNy3caLLprokhrLgjvZlTNGDBtr7BXttwXUlDvKVm53DjSIg1D2PgVnBlnf05b55iCElj4I= X-Received: by 2002:a05:6000:1a85:b0:3a3:4baa:3f3d with SMTP id ffacd0b85a97d-3b768c9c13dmr6966259f8f.6.1753392751358; Thu, 24 Jul 2025 14:32:31 -0700 (PDT) X-Google-Smtp-Source: AGHT+IEBbZa9GDR0ki0Hy0VjprS/a9IUEWZpzBMehLKY4L1dDoNNRYdZKztKjdVKH6ITX6Do3wdiKg== X-Received: by 2002:a05:6000:1a85:b0:3a3:4baa:3f3d with SMTP id ffacd0b85a97d-3b768c9c13dmr6966239f8f.6.1753392750862; Thu, 24 Jul 2025 14:32:30 -0700 (PDT) Received: from [192.168.3.141] (p57a1acc3.dip0.t-ipconnect.de. [87.161.172.195]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-3b76fcad2b4sm3213491f8f.47.2025.07.24.14.32.29 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 24 Jul 2025 14:32:30 -0700 (PDT) Message-ID: Date: Thu, 24 Jul 2025 23:32:29 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 2/5] mm/mseal: update madvise() logic To: Kees Cook , Lorenzo Stoakes Cc: Andrew Morton , "Liam R . Howlett" , Vlastimil Babka , Jann Horn , Pedro Falcato , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Jeff Xu References: <202507241352.22634450C9@keescook> From: David Hildenbrand Content-Language: en-US Autocrypt: addr=david@redhat.com; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzSREYXZpZCBIaWxk ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT7CwZgEEwEIAEICGwMGCwkIBwMCBhUIAgkKCwQW AgMBAh4BAheAAhkBFiEEG9nKrXNcTDpGDfzKTd4Q9wD/g1oFAmgsLPQFCRvGjuMACgkQTd4Q 9wD/g1o0bxAAqYC7gTyGj5rZwvy1VesF6YoQncH0yI79lvXUYOX+Nngko4v4dTlOQvrd/vhb 02e9FtpA1CxgwdgIPFKIuXvdSyXAp0xXuIuRPQYbgNriQFkaBlHe9mSf8O09J3SCVa/5ezKM OLW/OONSV/Fr2VI1wxAYj3/Rb+U6rpzqIQ3Uh/5Rjmla6pTl7Z9/o1zKlVOX1SxVGSrlXhqt kwdbjdj/csSzoAbUF/duDuhyEl11/xStm/lBMzVuf3ZhV5SSgLAflLBo4l6mR5RolpPv5wad GpYS/hm7HsmEA0PBAPNb5DvZQ7vNaX23FlgylSXyv72UVsObHsu6pT4sfoxvJ5nJxvzGi69U s1uryvlAfS6E+D5ULrV35taTwSpcBAh0/RqRbV0mTc57vvAoXofBDcs3Z30IReFS34QSpjvl Hxbe7itHGuuhEVM1qmq2U72ezOQ7MzADbwCtn+yGeISQqeFn9QMAZVAkXsc9Wp0SW/WQKb76 FkSRalBZcc2vXM0VqhFVzTb6iNqYXqVKyuPKwhBunhTt6XnIfhpRgqveCPNIasSX05VQR6/a OBHZX3seTikp7A1z9iZIsdtJxB88dGkpeMj6qJ5RLzUsPUVPodEcz1B5aTEbYK6428H8MeLq NFPwmknOlDzQNC6RND8Ez7YEhzqvw7263MojcmmPcLelYbfOwU0EVcufkQEQAOfX3n0g0fZz Bgm/S2zF/kxQKCEKP8ID+Vz8sy2GpDvveBq4H2Y34XWsT1zLJdvqPI4af4ZSMxuerWjXbVWb T6d4odQIG0fKx4F8NccDqbgHeZRNajXeeJ3R7gAzvWvQNLz4piHrO/B4tf8svmRBL0ZB5P5A 2uhdwLU3NZuK22zpNn4is87BPWF8HhY0L5fafgDMOqnf4guJVJPYNPhUFzXUbPqOKOkL8ojk CXxkOFHAbjstSK5Ca3fKquY3rdX3DNo+EL7FvAiw1mUtS+5GeYE+RMnDCsVFm/C7kY8c2d0G NWkB9pJM5+mnIoFNxy7YBcldYATVeOHoY4LyaUWNnAvFYWp08dHWfZo9WCiJMuTfgtH9tc75 7QanMVdPt6fDK8UUXIBLQ2TWr/sQKE9xtFuEmoQGlE1l6bGaDnnMLcYu+Asp3kDT0w4zYGsx 5r6XQVRH4+5N6eHZiaeYtFOujp5n+pjBaQK7wUUjDilPQ5QMzIuCL4YjVoylWiBNknvQWBXS lQCWmavOT9sttGQXdPCC5ynI+1ymZC1ORZKANLnRAb0NH/UCzcsstw2TAkFnMEbo9Zu9w7Kv AxBQXWeXhJI9XQssfrf4Gusdqx8nPEpfOqCtbbwJMATbHyqLt7/oz/5deGuwxgb65pWIzufa N7eop7uh+6bezi+rugUI+w6DABEBAAHCwXwEGAEIACYCGwwWIQQb2cqtc1xMOkYN/MpN3hD3 AP+DWgUCaCwtJQUJG8aPFAAKCRBN3hD3AP+DWlDnD/4k2TW+HyOOOePVm23F5HOhNNd7nNv3 Vq2cLcW1DteHUdxMO0X+zqrKDHI5hgnE/E2QH9jyV8mB8l/ndElobciaJcbl1cM43vVzPIWn 01vW62oxUNtEvzLLxGLPTrnMxWdZgxr7ACCWKUnMGE2E8eca0cT2pnIJoQRz242xqe/nYxBB /BAK+dsxHIfcQzl88G83oaO7vb7s/cWMYRKOg+WIgp0MJ8DO2IU5JmUtyJB+V3YzzM4cMic3 bNn8nHjTWw/9+QQ5vg3TXHZ5XMu9mtfw2La3bHJ6AybL0DvEkdGxk6YHqJVEukciLMWDWqQQ RtbBhqcprgUxipNvdn9KwNpGciM+hNtM9kf9gt0fjv79l/FiSw6KbCPX9b636GzgNy0Ev2UV m00EtcpRXXMlEpbP4V947ufWVK2Mz7RFUfU4+ETDd1scMQDHzrXItryHLZWhopPI4Z+ps0rB CQHfSpl+wG4XbJJu1D8/Ww3FsO42TMFrNr2/cmqwuUZ0a0uxrpkNYrsGjkEu7a+9MheyTzcm vyU2knz5/stkTN2LKz5REqOe24oRnypjpAfaoxRYXs+F8wml519InWlwCra49IUSxD1hXPxO WBe5lqcozu9LpNDH/brVSzHCSb7vjNGvvSVESDuoiHK8gNlf0v+epy5WYd7CGAgODPvDShGN g3eXuA== Organization: Red Hat In-Reply-To: <202507241352.22634450C9@keescook> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit > As an aside, why should discard work in this case even without step 4? > Wouldn't setting "read-only" imply you don't want the memory to change > out from under you? I guess I'm not clear on the semantics: how do memory > protection bits map to madvise actions like this? They generally don't affect MADV_DONTNEED behavior. The only documented (man page) reason for EPERM in the man page is related to MADV_HWPOISON. -- Cheers, David / dhildenb