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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5FE43C54E60 for ; Thu, 14 Mar 2024 16:39:55 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C195F800C5; Thu, 14 Mar 2024 12:39:54 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id BC7E8800B4; Thu, 14 Mar 2024 12:39:54 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A4153800C5; Thu, 14 Mar 2024 12:39:54 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 9299F800B4 for ; Thu, 14 Mar 2024 12:39:54 -0400 (EDT) Received: from smtpin21.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 622A11C19A5 for ; Thu, 14 Mar 2024 16:39:54 +0000 (UTC) X-FDA: 81896206308.21.85CB1F7 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.18]) by imf16.hostedemail.com (Postfix) with ESMTP id CD11D18001C for ; Thu, 14 Mar 2024 16:39:51 +0000 (UTC) Authentication-Results: imf16.hostedemail.com; dkim=pass header.d=intel.com header.s=Intel header.b=nnG78UqB; dmarc=pass (policy=none) header.from=intel.com; spf=pass (imf16.hostedemail.com: domain of dave.hansen@intel.com designates 192.198.163.18 as permitted sender) smtp.mailfrom=dave.hansen@intel.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1710434392; h=from:from:sender: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:dkim-signature; bh=mKwGkya3SJGlIBvnMnco4QNhzB2rqy23vTNx6dPVjcM=; b=a8I9gi7Uvo4Yt0gAv7LZKbjPgrt2p8+IhpZ+z83boHB/jz4Ovn8UAodiUXwCL+eVCE52u8 wIo49iIDq2mPX5fBQLf95sYTzxzy6Dmg994beu4zSI3rOQN8CHQTABwKqNL/AhkJi/CcXN ghd/jKAFNUN/H8aXuLCiPI2jhIDJNvc= ARC-Authentication-Results: i=1; imf16.hostedemail.com; dkim=pass header.d=intel.com header.s=Intel header.b=nnG78UqB; dmarc=pass (policy=none) header.from=intel.com; spf=pass (imf16.hostedemail.com: domain of dave.hansen@intel.com designates 192.198.163.18 as permitted sender) smtp.mailfrom=dave.hansen@intel.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1710434392; a=rsa-sha256; cv=none; b=4OxV06O7tUKEZ2Q+6Q9ecjHjz70PEamttM4dAcPG4Uw1YZcGzIgrJxnK6iTPRnr1/QzPXj 0bQZaOwsBZEO+YkzHJNP8oCHrgkkoVd3xLk5BUD7tEl1x2Zakirwz7MKpZbETpJp7SchQw 8PdFgP6lJnP6HWzuNwPvpduuwccRHkU= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1710434392; x=1741970392; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=djlTZ+NXt62CYBQD0EYVhAEkHu02AG1U5oefnk9Umf8=; b=nnG78UqBosY/HxQ9UuCzBXcahpQTZtkfWldfbYFOZuEpN1XMGsQckkNe PWD59iwDrvgfJrDUmeyudOEVImtOl2D/Pg9JjghRnjdDHa6CC29yZpSbq 4QPY9JE9PGnEm9exre4qSfR4zZaEzCbc+o+MB9mlQ1xtyaUJ0/Yo96q5S ou1/A962nPCiP9pakOzi3+Rz/tVriG9MCvy9SCzREZFYLUruyv3+yn7YW B2HPtdqfdfTad5+/trN6oldHjIRSRjtFN3FdT62OoEL9fXxngtQ3H0TQb acbYg+d4oyMsqwbq5j3fcCqexVR4bD8EX92tUgGBeJ7A8kdXqQdS9i9fe g==; X-IronPort-AV: E=McAfee;i="6600,9927,11013"; a="5116166" X-IronPort-AV: E=Sophos;i="6.07,125,1708416000"; d="scan'208";a="5116166" Received: from orviesa004.jf.intel.com ([10.64.159.144]) by fmvoesa112.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Mar 2024 09:39:50 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.07,125,1708416000"; d="scan'208";a="17014261" Received: from laallen-mobl.amr.corp.intel.com (HELO [10.209.21.198]) ([10.209.21.198]) by orviesa004-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Mar 2024 09:39:50 -0700 Message-ID: <24f71d52-0891-4cfc-8dec-9f13ed618eee@intel.com> Date: Thu, 14 Mar 2024 09:39:51 -0700 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 1/1] x86/elf: Add a new .note section containing Xfeatures information to x86 core files Content-Language: en-US To: Borislav Petkov Cc: Vignesh Balasubramanian , linux-kernel@vger.kernel.org, linux-toolchains@vger.kernel.org, mpe@ellerman.id.au, npiggin@gmail.com, christophe.leroy@csgroup.eu, aneesh.kumar@kernel.org, naveen.n.rao@linux.ibm.com, ebiederm@xmission.com, keescook@chromium.org, x86@kernel.org, linuxppc-dev@lists.ozlabs.org, linux-mm@kvack.org, jinisusan.george@amd.com, matz@suse.de, binutils@sourceware.org, jhb@freebsd.org, felix.willgerodt@intel.com References: <20240314112359.50713-1-vigbalas@amd.com> <20240314112359.50713-2-vigbalas@amd.com> <20240314160824.GDZfMg-J1VOyjxIMiV@fat_crate.local> <6ce6aa20-25d2-4784-823f-2a18f592e002@intel.com> <20240314162954.GAZfMmAnYQoRjRbRzc@fat_crate.local> From: Dave Hansen Autocrypt: addr=dave.hansen@intel.com; keydata= xsFNBE6HMP0BEADIMA3XYkQfF3dwHlj58Yjsc4E5y5G67cfbt8dvaUq2fx1lR0K9h1bOI6fC oAiUXvGAOxPDsB/P6UEOISPpLl5IuYsSwAeZGkdQ5g6m1xq7AlDJQZddhr/1DC/nMVa/2BoY 2UnKuZuSBu7lgOE193+7Uks3416N2hTkyKUSNkduyoZ9F5twiBhxPJwPtn/wnch6n5RsoXsb ygOEDxLEsSk/7eyFycjE+btUtAWZtx+HseyaGfqkZK0Z9bT1lsaHecmB203xShwCPT49Blxz VOab8668QpaEOdLGhtvrVYVK7x4skyT3nGWcgDCl5/Vp3TWA4K+IofwvXzX2ON/Mj7aQwf5W iC+3nWC7q0uxKwwsddJ0Nu+dpA/UORQWa1NiAftEoSpk5+nUUi0WE+5DRm0H+TXKBWMGNCFn c6+EKg5zQaa8KqymHcOrSXNPmzJuXvDQ8uj2J8XuzCZfK4uy1+YdIr0yyEMI7mdh4KX50LO1 pmowEqDh7dLShTOif/7UtQYrzYq9cPnjU2ZW4qd5Qz2joSGTG9eCXLz5PRe5SqHxv6ljk8mb ApNuY7bOXO/A7T2j5RwXIlcmssqIjBcxsRRoIbpCwWWGjkYjzYCjgsNFL6rt4OL11OUF37wL QcTl7fbCGv53KfKPdYD5hcbguLKi/aCccJK18ZwNjFhqr4MliQARAQABzUVEYXZpZCBDaHJp c3RvcGhlciBIYW5zZW4gKEludGVsIFdvcmsgQWRkcmVzcykgPGRhdmUuaGFuc2VuQGludGVs LmNvbT7CwXgEEwECACIFAlQ+9J0CGwMGCwkIBwMCBhUIAgkKCwQWAgMBAh4BAheAAAoJEGg1 lTBwyZKwLZUP/0dnbhDc229u2u6WtK1s1cSd9WsflGXGagkR6liJ4um3XCfYWDHvIdkHYC1t MNcVHFBwmQkawxsYvgO8kXT3SaFZe4ISfB4K4CL2qp4JO+nJdlFUbZI7cz/Td9z8nHjMcWYF IQuTsWOLs/LBMTs+ANumibtw6UkiGVD3dfHJAOPNApjVr+M0P/lVmTeP8w0uVcd2syiaU5jB aht9CYATn+ytFGWZnBEEQFnqcibIaOrmoBLu2b3fKJEd8Jp7NHDSIdrvrMjYynmc6sZKUqH2 I1qOevaa8jUg7wlLJAWGfIqnu85kkqrVOkbNbk4TPub7VOqA6qG5GCNEIv6ZY7HLYd/vAkVY E8Plzq/NwLAuOWxvGrOl7OPuwVeR4hBDfcrNb990MFPpjGgACzAZyjdmYoMu8j3/MAEW4P0z F5+EYJAOZ+z212y1pchNNauehORXgjrNKsZwxwKpPY9qb84E3O9KYpwfATsqOoQ6tTgr+1BR CCwP712H+E9U5HJ0iibN/CDZFVPL1bRerHziuwuQuvE0qWg0+0SChFe9oq0KAwEkVs6ZDMB2 P16MieEEQ6StQRlvy2YBv80L1TMl3T90Bo1UUn6ARXEpcbFE0/aORH/jEXcRteb+vuik5UGY 5TsyLYdPur3TXm7XDBdmmyQVJjnJKYK9AQxj95KlXLVO38lczsFNBFRjzmoBEACyAxbvUEhd GDGNg0JhDdezyTdN8C9BFsdxyTLnSH31NRiyp1QtuxvcqGZjb2trDVuCbIzRrgMZLVgo3upr MIOx1CXEgmn23Zhh0EpdVHM8IKx9Z7V0r+rrpRWFE8/wQZngKYVi49PGoZj50ZEifEJ5qn/H Nsp2+Y+bTUjDdgWMATg9DiFMyv8fvoqgNsNyrrZTnSgoLzdxr89FGHZCoSoAK8gfgFHuO54B lI8QOfPDG9WDPJ66HCodjTlBEr/Cwq6GruxS5i2Y33YVqxvFvDa1tUtl+iJ2SWKS9kCai2DR 3BwVONJEYSDQaven/EHMlY1q8Vln3lGPsS11vSUK3QcNJjmrgYxH5KsVsf6PNRj9mp8Z1kIG qjRx08+nnyStWC0gZH6NrYyS9rpqH3j+hA2WcI7De51L4Rv9pFwzp161mvtc6eC/GxaiUGuH BNAVP0PY0fqvIC68p3rLIAW3f97uv4ce2RSQ7LbsPsimOeCo/5vgS6YQsj83E+AipPr09Caj 0hloj+hFoqiticNpmsxdWKoOsV0PftcQvBCCYuhKbZV9s5hjt9qn8CE86A5g5KqDf83Fxqm/ vXKgHNFHE5zgXGZnrmaf6resQzbvJHO0Fb0CcIohzrpPaL3YepcLDoCCgElGMGQjdCcSQ+Ci FCRl0Bvyj1YZUql+ZkptgGjikQARAQABwsFfBBgBAgAJBQJUY85qAhsMAAoJEGg1lTBwyZKw l4IQAIKHs/9po4spZDFyfDjunimEhVHqlUt7ggR1Hsl/tkvTSze8pI1P6dGp2XW6AnH1iayn yRcoyT0ZJ+Zmm4xAH1zqKjWplzqdb/dO28qk0bPso8+1oPO8oDhLm1+tY+cOvufXkBTm+whm +AyNTjaCRt6aSMnA/QHVGSJ8grrTJCoACVNhnXg/R0g90g8iV8Q+IBZyDkG0tBThaDdw1B2l asInUTeb9EiVfL/Zjdg5VWiF9LL7iS+9hTeVdR09vThQ/DhVbCNxVk+DtyBHsjOKifrVsYep WpRGBIAu3bK8eXtyvrw1igWTNs2wazJ71+0z2jMzbclKAyRHKU9JdN6Hkkgr2nPb561yjcB8 sIq1pFXKyO+nKy6SZYxOvHxCcjk2fkw6UmPU6/j/nQlj2lfOAgNVKuDLothIxzi8pndB8Jju KktE5HJqUUMXePkAYIxEQ0mMc8Po7tuXdejgPMwgP7x65xtfEqI0RuzbUioFltsp1jUaRwQZ MTsCeQDdjpgHsj+P2ZDeEKCbma4m6Ez/YWs4+zDm1X8uZDkZcfQlD9NldbKDJEXLIjYWo1PH hYepSffIWPyvBMBTW2W5FRjJ4vLRrJSUoEfJuPQ3vW9Y73foyo/qFoURHO48AinGPZ7PC7TF vUaNOTjKedrqHkaOcqB185ahG2had0xnFsDPlx5y In-Reply-To: <20240314162954.GAZfMmAnYQoRjRbRzc@fat_crate.local> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: CD11D18001C X-Stat-Signature: msf8157sxdx5i9ctx5utq4br1jzdqumf X-Rspam-User: X-HE-Tag: 1710434391-777713 X-HE-Meta: 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 3/14/24 09:29, Borislav Petkov wrote: > >> That argument breaks down a bit on the flags though: >> >> xc.xfeat_flags = xstate_flags[i]; >> >> Because it comes _directly_ from CPUID with zero filtering: >> >> cpuid_count(XSTATE_CPUID, i, &eax, &ebx, &ecx, &edx); >> ... >> xstate_flags[i] = ecx; >> >> So this layout is quite dependent on what's in x86's CPUID. > Yeah, no, this should not be copying CPUID flags - those flags should be > *translated* to independently defined flags which describe those > buffers. Ditto for: xc.xfeat_type = i; Right now, that's bound to CPUID and XSAVE. "feat_type==10" can only ever be PKRU and that's derived from the XSAVE architecture. If you want this to be extensible to things outside of the XSAVE architecture, it needs to be something actually extensible and not entangled with XSAVE. In other words "xc.xfeat_type" can enumerate XSAVE state components being in the dump, but it should not be limited to XSAVE. Just as an example: enum feat_type { FEATURE_XSAVE_PKRU, FEATURE_XSAVE__YMM, FEATURE_XSAVE_BNDREGS, FEATURE_XSAVE_BNDCSR, ... RANDOM_STATE_NOT_XSAVE }; See how feat_type==1 is PKRU and *NOT* feat_type==10? That opens the door to RANDOM_STATE_NOT_XSAVE or anything else you want. This would be _actually_ extensible.