Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752067AbbKIPGb (ORCPT ); Mon, 9 Nov 2015 10:06:31 -0500 Received: from mail-ig0-f179.google.com ([209.85.213.179]:37146 "EHLO mail-ig0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751556AbbKIPG2 (ORCPT ); Mon, 9 Nov 2015 10:06:28 -0500 Subject: Re: [PATCH 0/4] dm verity: add support for error correction To: Mikulas Patocka , Sami Tolvanen References: <1446688954-29589-1-git-send-email-samitolvanen@google.com> <563B066C.6050202@redhat.com> <20151106190634.GA2813@google.com> Cc: Milan Broz , device-mapper development , Mandeep Baines , Will Drewry , Kees Cook , Mike Snitzer , linux-kernel@vger.kernel.org, Alasdair Kergon , Mark Salyzyn From: Austin S Hemmelgarn Message-ID: <5640B669.6030905@gmail.com> Date: Mon, 9 Nov 2015 10:06:17 -0500 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: Content-Type: multipart/signed; protocol="application/pkcs7-signature"; micalg=sha-512; boundary="------------ms080107040803070309070605" X-Antivirus: avast! (VPS 151109-0, 2015-11-09), Outbound message X-Antivirus-Status: Clean Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6133 Lines: 104 This is a cryptographically signed message in MIME format. --------------ms080107040803070309070605 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: quoted-printable On 2015-11-07 10:18, Mikulas Patocka wrote: > > > On Fri, 6 Nov 2015, Sami Tolvanen wrote: > >> On Fri, Nov 06, 2015 at 12:23:29PM -0500, Mikulas Patocka wrote: >>> Do you have some real case where such error corrections >>> increase longevity of some device? >> >> Yes, there have been several cases where read-only partition errors >> have rendered a device unusable. The sheer volume of mobile devices >> means that even if a tiny fraction of them suffer from such a problem,= >> it's going to affect a large number of people. > > Why don't you reflash the device from bootloader? (by holding power and= > volume keys simultaneously on startup and using the fastboot utility) Requiring an end user to re-flash their device is not good business=20 practice, even if it is a rare occurrence (it adds a potential=20 attack-vector for malware, and is decidedly non-trivial to do for=20 someone without programming background). Phones, tablets, and other=20 embedded systems are the type of thing where the device needs to be=20 usable when the user wants to access it, period. Minimizing the chances = of the device not working (even for less common causes like this patch=20 tries to protect against) is crucial to making the user experience as=20 good as possible (and reducing customer support costs). --------------ms080107040803070309070605 Content-Type: application/pkcs7-signature; name="smime.p7s" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="smime.p7s" Content-Description: S/MIME Cryptographic Signature MIAGCSqGSIb3DQEHAqCAMIACAQExDzANBglghkgBZQMEAgMFADCABgkqhkiG9w0BBwEAAKCC Brgwgga0MIIEnKADAgECAgMRLfgwDQYJKoZIhvcNAQENBQAweTEQMA4GA1UEChMHUm9vdCBD QTEeMBwGA1UECxMVaHR0cDovL3d3dy5jYWNlcnQub3JnMSIwIAYDVQQDExlDQSBDZXJ0IFNp Z25pbmcgQXV0aG9yaXR5MSEwHwYJKoZIhvcNAQkBFhJzdXBwb3J0QGNhY2VydC5vcmcwHhcN MTUwOTIxMTEzNTEzWhcNMTYwMzE5MTEzNTEzWjBjMRgwFgYDVQQDEw9DQWNlcnQgV29UIFVz ZXIxIzAhBgkqhkiG9w0BCQEWFGFoZmVycm9pbjdAZ21haWwuY29tMSIwIAYJKoZIhvcNAQkB FhNhaGVtbWVsZ0BvaGlvZ3QuY29tMIICIjANBgkqhkiG9w0BAQEFAAOCAg8AMIICCgKCAgEA nQ/81tq0QBQi5w316VsVNfjg6kVVIMx760TuwA1MUaNQgQ3NyUl+UyFtjhpkNwwChjgAqfGd LIMTHAdObcwGfzO5uI2o1a8MHVQna8FRsU3QGouysIOGQlX8jFYXMKPEdnlt0GoQcd+BtESr pivbGWUEkPs1CwM6WOrs+09bAJP3qzKIr0VxervFrzrC5Dg9Rf18r9WXHElBuWHg4GYHNJ2V Ab8iKc10h44FnqxZK8RDN8ts/xX93i9bIBmHnFfyNRfiOUtNVeynJbf6kVtdHP+CRBkXCNRZ qyQT7gbTGD24P92PS2UTmDfplSBcWcTn65o3xWfesbf02jF6PL3BCrVnDRI4RgYxG3zFBJuG qvMoEODLhHKSXPAyQhwZINigZNdw5G1NqjXqUw+lIqdQvoPijK9J3eijiakh9u2bjWOMaleI SMRR6XsdM2O5qun1dqOrCgRkM0XSNtBQ2JjY7CycIx+qifJWsRaYWZz0aQU4ZrtAI7gVhO9h pyNaAGjvm7PdjEBiXq57e4QcgpwzvNlv8pG1c/hnt0msfDWNJtl3b6elhQ2Pz4w/QnWifZ8E BrFEmjeeJa2dqjE3giPVWrsH+lOvQQONsYJOuVb8b0zao4vrWeGmW2q2e3pdv0Axzm/60cJQ haZUv8+JdX9ZzqxOm5w5eUQSclt84u+D+hsCAwEAAaOCAVkwggFVMAwGA1UdEwEB/wQCMAAw VgYJYIZIAYb4QgENBEkWR1RvIGdldCB5b3VyIG93biBjZXJ0aWZpY2F0ZSBmb3IgRlJFRSBo ZWFkIG92ZXIgdG8gaHR0cDovL3d3dy5DQWNlcnQub3JnMA4GA1UdDwEB/wQEAwIDqDBABgNV HSUEOTA3BggrBgEFBQcDBAYIKwYBBQUHAwIGCisGAQQBgjcKAwQGCisGAQQBgjcKAwMGCWCG SAGG+EIEATAyBggrBgEFBQcBAQQmMCQwIgYIKwYBBQUHMAGGFmh0dHA6Ly9vY3NwLmNhY2Vy dC5vcmcwMQYDVR0fBCowKDAmoCSgIoYgaHR0cDovL2NybC5jYWNlcnQub3JnL3Jldm9rZS5j cmwwNAYDVR0RBC0wK4EUYWhmZXJyb2luN0BnbWFpbC5jb22BE2FoZW1tZWxnQG9oaW9ndC5j b20wDQYJKoZIhvcNAQENBQADggIBADMnxtSLiIunh/TQcjnRdf63yf2D8jMtYUm4yDoCF++J jCXbPQBGrpCEHztlNSGIkF3PH7ohKZvlqF4XePWxpY9dkr/pNyCF1PRkwxUURqvuHXbu8Lwn 8D3U2HeOEU3KmrfEo65DcbanJCMTTW7+mU9lZICPP7ZA9/zB+L0Gm1UNFZ6AU50N/86vjQfY WgkCd6dZD4rQ5y8L+d/lRbJW7ZGEQw1bSFVTRpkxxDTOwXH4/GpQfnfqTAtQuJ1CsKT12e+H NSD/RUWGTr289dA3P4nunBlz7qfvKamxPymHeBEUcuICKkL9/OZrnuYnGROFwcdvfjGE5iLB kjp/ttrY4aaVW5EsLASNgiRmA6mbgEAMlw3RwVx0sVelbiIAJg9Twzk4Ct6U9uBKiJ8S0sS2 8RCSyTmCRhJs0vvva5W9QUFGmp5kyFQEoSfBRJlbZfGX2ehI2Hi3U2/PMUm2ONuQG1E+a0AP u7I0NJc/Xil7rqR0gdbfkbWp0a+8dAvaM6J00aIcNo+HkcQkUgtfrw+C2Oyl3q8IjivGXZqT 5UdGUb2KujLjqjG91Dun3/RJ/qgQlotH7WkVBs7YJVTCxfkdN36rToPcnMYOI30FWa0Q06gn F6gUv9/mo6riv3A5bem/BdbgaJoPnWQD9D8wSyci9G4LKC+HQAMdLmGoeZfpJzKHMYIE0TCC BM0CAQEwgYAweTEQMA4GA1UEChMHUm9vdCBDQTEeMBwGA1UECxMVaHR0cDovL3d3dy5jYWNl cnQub3JnMSIwIAYDVQQDExlDQSBDZXJ0IFNpZ25pbmcgQXV0aG9yaXR5MSEwHwYJKoZIhvcN AQkBFhJzdXBwb3J0QGNhY2VydC5vcmcCAxEt+DANBglghkgBZQMEAgMFAKCCAiEwGAYJKoZI hvcNAQkDMQsGCSqGSIb3DQEHATAcBgkqhkiG9w0BCQUxDxcNMTUxMTA5MTUwNjE3WjBPBgkq hkiG9w0BCQQxQgRAmI840ckN1AoKR9QUwo43KphELvqKAjgEsheeBGFATSnlsxDOyTsExXjG iENCHb6YpiR4u4+9SpRnRRn+kQaGgjBsBgkqhkiG9w0BCQ8xXzBdMAsGCWCGSAFlAwQBKjAL BglghkgBZQMEAQIwCgYIKoZIhvcNAwcwDgYIKoZIhvcNAwICAgCAMA0GCCqGSIb3DQMCAgFA MAcGBSsOAwIHMA0GCCqGSIb3DQMCAgEoMIGRBgkrBgEEAYI3EAQxgYMwgYAweTEQMA4GA1UE ChMHUm9vdCBDQTEeMBwGA1UECxMVaHR0cDovL3d3dy5jYWNlcnQub3JnMSIwIAYDVQQDExlD QSBDZXJ0IFNpZ25pbmcgQXV0aG9yaXR5MSEwHwYJKoZIhvcNAQkBFhJzdXBwb3J0QGNhY2Vy dC5vcmcCAxEt+DCBkwYLKoZIhvcNAQkQAgsxgYOggYAweTEQMA4GA1UEChMHUm9vdCBDQTEe MBwGA1UECxMVaHR0cDovL3d3dy5jYWNlcnQub3JnMSIwIAYDVQQDExlDQSBDZXJ0IFNpZ25p bmcgQXV0aG9yaXR5MSEwHwYJKoZIhvcNAQkBFhJzdXBwb3J0QGNhY2VydC5vcmcCAxEt+DAN BgkqhkiG9w0BAQEFAASCAgACEvnt+VKQo/KRRptB5nc9Bq9vshbGPNYfIP1ii0JJwJ6OpnF2 roGIQoaK8ptbakTxtlemIWz6pPTxJRvzTrtUib3bPkCwwR4EJyeGyBpgcRfcZL0oqaTzXWB/ Ju5MRRRdPbfrYB9U0y4isWmSOcItEgiBv+gqVGZRCbjuywsukwh55ZwcrE9KQaVFohEBeUEo O07ppcqfOJCBb7Zx/qM8/FQwwIVxHxRvnXkAWnC9FpAnVVL04kdBVUr+hVYmqm5RBkG8T//u UBHI7r8UCXjOiZVUrkDKJSMDX0tpiz09WdVpm+ztuW71bLqBF66E/qn2+bsuCPXWvKOvelx4 i43wX7c6rVrR5nilUZxw6rMcbNG37Q0UNS9Me8i0jNLrifMCHYPH/v6U0mqwIfyipbW5CFMa /1SSJnE2yG6Nd0riUm6R3LcMQwlIVgAZEiApgDACUJTgmsb6t17/S2ooAsndht53ww3WimOA R8rVP5HlgsOpuUBTOe4YPEXaD/WzGt6ih9BOSqn95fLssNzoGs3LgdB/Rbo0FaoSiVTy8cVF 6tUTX+lpj2e5/dvz88/HhAWgqaQWDcwrfVJ2jbN7FLS0hwE+ezkKWH6vwkHlFF8DlGpFrgCg MNftWdI4a3Pn1fabskIVvVQNOTnkdTyamQ1URO7ikCQgbf2KHCpydMV8+wAAAAAAAA== --------------ms080107040803070309070605-- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/