From owner-freebsd-stable@freebsd.org Tue Dec 18 10:22:56 2018 Return-Path: Delivered-To: freebsd-stable@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 8B3F1134C244 for ; Tue, 18 Dec 2018 10:22:56 +0000 (UTC) (envelope-from alexander.lochmann@tu-dortmund.de) Received: from unimail.uni-dortmund.de (mx1.hrz.uni-dortmund.de [129.217.128.51]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "unimail.tu-dortmund.de", Issuer "TU Dortmund CA - G01" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 032CE8C702 for ; Tue, 18 Dec 2018 10:22:55 +0000 (UTC) (envelope-from alexander.lochmann@tu-dortmund.de) Received: from [129.217.64.44] (dynip-129-217-064-044.wifi.tu-dortmund.de [129.217.64.44]) (authenticated bits=0) by unimail.uni-dortmund.de (8.16.0.29/8.16.0.29) with ESMTPSA id wBIAMs51027349 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT); Tue, 18 Dec 2018 11:22:54 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=tu-dortmund.de; s=unimail; t=1545128574; bh=GIZT37uyGn4YwsVAA2VNZnOlZLs8lnGH+zBbFI+xrNc=; h=To:Cc:References:From:Subject:Date:In-Reply-To; b=ncJub/JbfVs02yXbpBmp0QaIbllZXXnU5utiv3hwHgUwrL7ytk+HEsVr2HRW+y06y 8h40mlVpyUV6tW7A2p0lPiVSwmbEZtlAIFoBa14axGC6OFjRbbMnb/4ftT4KoNqQVX /FQs1zj9OntWwMHcby26k+51Y+Et/cNgxV18J7/Q= To: Konstantin Belousov Cc: freebsd-stable@freebsd.org, Horst Schirmeier References: <38ad0d50-c776-9deb-d56b-db8db548cefc@tu-dortmund.de> <20181218052738.GZ60291@kib.kiev.ua> <40f4db11-84cb-9b8d-2eb5-5882ad01d1d8@tu-dortmund.de> <20181218100159.GE60291@kib.kiev.ua> From: Alexander Lochmann Openpgp: preference=signencrypt Autocrypt: addr=alexander.lochmann@tu-dortmund.de; prefer-encrypt=mutual; keydata= mQINBFQIyUEBEADZ+x+Ssg/46SiU66zm2lPGYAdqYfmXVv+sf/23+/KSj0FQHZKywzWjsmgR vWZZVlGJolwcW3MJ/g6ctZeOpfYiZVpzbZwNgKU0ETGjUmqmlq5/o5KnENKOimZzaKSaNn9p IC+EIeWXvu7pQjW0w1bK/RVVNw0p1Iz82W4Z+vKtD8CS+YJLAcZ6YoZMvQEg84O9odlV2Ryp oVj9EzHH40TWEdtgd4pQkaOks01PEr19sJXUjnP0VxLfs91AZjRnmGJKnI4HcrOKwquoQEeL DtHCxK0VNeoXCWkz33uBxSL5cicQ7D09hxjWthMilUpDZT94x0K452q4nybQ1TSLTYC8mlW+ xKUvJmqfHZbITJ10dTgjNvOe0kLbpXeQ1789lNmnA9bkQAK5Cefo55WbXmr1Mo3PV7y0XCib OaiijPlZo/Isc03EOK3lHPK8NuY8G+ftvphO4RyXCUWXw/o01cDnPaIEcTWkUbXvMhf/6ltP 1QWEfkguzGVjTw7Xssm9YuokC+P+49JKRyZzyCJZ022OxMlsX6c1BNZ4+cWUNmn6xr1xRNse SglpMLL1m3K1KuLf1hdAor6PBzFLiLa33lUhsWtg1ACFhpfZZOQRVas2McXTYUUpmCzOYI5F +km5q6cZStr9m7O3Y3DDGotiaJDpLtATwZ4MIM4ADbg/xl6ZgwARAQABtDZBbGV4YW5kZXIg TG9jaG1hbm4gPGFsZXhhbmRlci5sb2NobWFubkB0dS1kb3J0bXVuZC5kZT6JAj4EEwECACgF AlQIyUECGyMFCQlmAYAGCwkIBwMCBhUIAgkKCwQWAgMBAh4BAheAAAoJEFk+7QW8Pvb9I34Q AIEGy9Pt1nK8r+0baVF5KBXzoZuQIQ7ZfxJ0MFrCQSvRYEWevm2a0p5lBDOpb/VL8VtYMVO2 xZewerWoXyWMIeWmmCeSuVGdLDT/YV6BA54KzJkptmXxQaUVdiY+Fl0jxFODAXvSxI36MdzQ PFMwcSqxs5lZaxxyUWPidwanaQ5QNkShY2ljFD8gnKALiCxd/PqexLRlLinvqJ01EArxmPum PeA6nckWh4PGk1IGm7FiNZ5TYhCaq9lh5Hg5LsSJhJrOfgeT92hI7cLEwjKvRLrjH+NzbNFW tX4gWlwUHU5afP71AY9RfNXt/Ul8w+R5CX6W9xaiuS5MZZS5SZYeHU5QAfqaomSRkVb2uqwf Lahx76ONwOtsVbMLshaA9mxsgMUNDhOYxyKQOnYz2qThwZloEOgICaxIZG7WJug0HL4YGXG7 EJdFn2fEs6WUCeZ1DWGUGf92N+AFMBBJ/HP1fVlkAwuubOF7QdPTrsGwd8Tz0tkFzxd/W496 OvGO/OZZCw+pKnDODJyXtBs3jr6cu9evEasiaQEVL+nfhTGyNVW+dldn6uj7tJ3qLQbuk+o4 BLrUwjWXLdA4nMEGgtm8WabEyjoolP2BfjMTgEFQHhxaW0t4fIYLO5kM3lNphwXxmA4Lys+x RCPyLSitlqwrqDW19v56NTipcAqsczgpGZRGuQINBFQIyUEBEACcIW4RnxXteHv/Hl4/l926 sozOCL8iwT/OD9QvL3171Y1MDX8bt8LneMoh5RG4SegtdVaA4jLkdv8BTmRbY7qZrzJjYJX4 PUyvmuZbqpa+PF1c5uqUcuhwpXlQAupL1dCgO5p1xbdCxEOB9Lm+2hUFJy1LsvidwieJdFqR l09a/IypKtqywJxa6sSJp9ZPPCPMJnJxIVzGqAwHWO84LfIX5I6BRUbqAhxljJm40Bk79z+P HdytD0SaTuWIhsVYRFchKLxqbXokUhJaWupE1v4xFe2Sqty9vSCrJZMRZRTLvngRxbJVHIJJ sK685HNS3QJSrFtql+SGMkPHpX92+ZCmyTH6DAQ3Y0MtjJTcoYKu3fI8KT9BSsLuuXUToX7Y l4RbFB5s0rwZ2XMweKJdkwypC5fSZmLtEwgimMQ4VfBBUPJCvHhmvOHKX3Wls99D7xYWP7Lr iinmjbduiaO/A+bLjAdLqqGJpjQ7T3z+vqxzp3IaeJ3ObSnnnPppcKVAf6qZqu5Yfc31q/OY n19WyGIhwK3MuuVmjatxMmGgkSxzgTTP3jFQ008qymPcgrvgOR+MECCIpXjOMfenOhhsKnhu F7hxUS/6JtYKsEMEwJXVN509sNhJiEzSY9q+VYn9IArHSBMmpi5l6XvI1iwPD9HRNursPxKV lfi8lQsC7zxuTQARAQABiQIlBBgBAgAPBQJUCMlBAhsMBQkJZgGAAAoJEFk+7QW8Pvb9EkkP /2LyGWWOoTAGBhzvgKiYzarS3WQNZCuFHSfB/XXg4SRSX3NsxGVZWdLvVVgzWo1+tC1Qk6wO IVQSSw20wQXe8boZ8yiB8eM4ohfS0lySO9gOkQLYLijWg3JIYwTbqyK2X8LpbCs7eUTXM9NO 6pmVtoc3LBBIXQElX8ir0BZZ19OCSConTkyVHYK6IbEJ11PxjJG5ZS7anI4FQt0muzykZrhk bmf5IV3DtJ/KUfhQjnJa2B/KoT7F6vpTCoyPtaBUHQXEAb2NaZVwF06WXsqfX4yleym3Jlfx Rfa4+BOJ4Gf2EFd3wYCsIb33ulaXBLWa8w3A/FdQSW9NBM4iYlPxRg+5eXn+oajpyKqPLetH WRNMN4NSHVSpu+JRqRlTDO3HCn/peQ0OB/Iaf3HN3DLZdbjtZY40xl1iR9TMgD2fn2MlAFy3 dSKfjeCAQYP9can1MgebE729MI7QhtzuUYdHy+iJO/ENNlSgFo5DLwRqssEGqWag0xWPgcni UAERITTzHJeevSeZh5ThHyD173Pwn+tIhR4bK5RFy/gnzwqHckl8Hw7o06m51yI4dUVeatNT mAiNrmW3iQnvehjLZOYXOXx4ovsWdvQn01dUo3gCXdEWQ5yQLOQRGTCcrq1hzCEd//viy9oT spNrcZJf1pbo3EKkCwUPAltq51ramtYzOu4K Subject: Re: Address Collision using i386 4G/4G Memory Split Message-ID: <24cb941b-1d27-1621-f437-18ed3b22cc7d@tu-dortmund.de> Date: Tue, 18 Dec 2018 11:22:53 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.2.1 MIME-Version: 1.0 In-Reply-To: <20181218100159.GE60291@kib.kiev.ua> Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="sXHw2nIg3q8q7jCYTZEyHv8BEf46lMiT2" X-Rspamd-Queue-Id: 032CE8C702 X-Spamd-Bar: ------ Authentication-Results: mx1.freebsd.org X-Spamd-Result: default: False [-6.99 / 15.00]; NEURAL_HAM_MEDIUM(-1.00)[-1.000,0]; NEURAL_HAM_SHORT(-0.99)[-0.995,0]; REPLY(-4.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000,0] X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 18 Dec 2018 10:22:56 -0000 This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --sXHw2nIg3q8q7jCYTZEyHv8BEf46lMiT2 Content-Type: multipart/mixed; boundary="L6ZdTpH16fJuq47p8YUAwJClhfaRYs6G3"; protected-headers="v1" From: Alexander Lochmann To: Konstantin Belousov Cc: freebsd-stable@freebsd.org, Horst Schirmeier Message-ID: <24cb941b-1d27-1621-f437-18ed3b22cc7d@tu-dortmund.de> Subject: Re: Address Collision using i386 4G/4G Memory Split References: <38ad0d50-c776-9deb-d56b-db8db548cefc@tu-dortmund.de> <20181218052738.GZ60291@kib.kiev.ua> <40f4db11-84cb-9b8d-2eb5-5882ad01d1d8@tu-dortmund.de> <20181218100159.GE60291@kib.kiev.ua> In-Reply-To: <20181218100159.GE60291@kib.kiev.ua> --L6ZdTpH16fJuq47p8YUAwJClhfaRYs6G3 Content-Type: text/plain; charset=utf-8 Content-Language: de-DE Content-Transfer-Encoding: quoted-printable >> Some context: We are doing VM-based tracing in the FreeBSD kernel. For= >> that, we observe parts of the kernel memory (allocations, accesses,...= ). >> Before 12.0 we simply knew that kernel addresses that we logged were >> unique. Moreover, when a memory access to a region of interest happene= d >> we knew that could only be kernel memory. >> We know have to ensure that we only record memory accesses that happen= >> within the kernel. >> Our approach is to record the kernels value for the CR3 register, and >> record memory accesses if the CR3 registers holds the aforementioned v= alue. > You must use CPL to see if the current operation mode is user or kernel= =2E > If user, nothing should be done (this would avoid vm86). If kernel, you= > need to compare current %cr3 with IdlePTD (IdlePTDP for PAE case). >=20 Thanks for the advice! We'll include that in our toolchain. Do you use PLs other than 0(=3Dkernel) and 3(=3Duser)? - Alex --=20 Technische Universit=C3=A4t Dortmund Alexander Lochmann PGP key: 0xBC3EF6FD Otto-Hahn-Str. 16 phone: +49.231.7556141 D-44227 Dortmund fax: +49.231.7556116 http://ess.cs.tu-dortmund.de/Staff/al --L6ZdTpH16fJuq47p8YUAwJClhfaRYs6G3-- --sXHw2nIg3q8q7jCYTZEyHv8BEf46lMiT2 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCgAdFiEElhZsUHzVP0dbkjCRWT7tBbw+9v0FAlwYyn4ACgkQWT7tBbw+ 9v2ZWQ/9HKwtTN7ztCaHUeiiW235scwYh9nLxXLJpHhwh1qCUre+jIVXMJpSXlkv gSo1b9Uc0EjDaBokRmlPUZek1gw1bcNyZ5acJkqBP6N/5F+g6xlhwANIGrBNtm8u AJX4PXyzMFDBVlSol3pE3xwwMVEVC9/Dc11dFEy9CBCCTiU0FslLMZCSguIAcwD9 M7dh0C0alNgWbanmRz9jRjvXymPAZy6ULx/FJKi2zO6R18qray3O1E5T3WP0xu9y ujYnZ2WBxx7WaFhHw7hAlzAiMHSUxmjXE2gEjnkZS6Pxn7IwcMs7BI9kpaj71o3H mHLFAH/D8t8Fs844PDQ4u8xgZx6+UtQ2umKT845LNA865xP9yD6tA12ACa/3gZyp YwwTjJ2tv2C7E2lLTe8lqmNTdUrWBUvnOu69+YXjIVi/DK019tCjV7H9DkoToc1w UdfB7cRf+u8xzLd+sDxkNIln9zIO6kFKArkRUaUIuzegwQGduZEpI/fEI++/6YDr UBHuPuFCBQE4rv+xZC2QpRvdL4iIvsCDE9VIvwKq6CKwh6tUWsLCjSPFLcPjegtW BSiS1Fc9Jmv4cJq6fIFIGhNaST2hcMNNErMAxTaBJDhsO+Pvu/aYPdFv45P0FI+R p6vk2DuMOCEuSZvEtTwROKh6MEX7b3D16pI6+Q85BCIL88zjw8A= =QXY5 -----END PGP SIGNATURE----- --sXHw2nIg3q8q7jCYTZEyHv8BEf46lMiT2--