Received: by 2002:a05:7412:ba23:b0:fa:4c10:6cad with SMTP id jp35csp631096rdb; Thu, 18 Jan 2024 14:01:51 -0800 (PST) X-Google-Smtp-Source: AGHT+IGskdzy1biQny2qlR/G/5cx4JIkPqxC9LBLsrESyrDXuMslrdV1Fea6mysdpJh/DaTuvkkx X-Received: by 2002:a05:620a:28c8:b0:783:22b2:7bcc with SMTP id l8-20020a05620a28c800b0078322b27bccmr402790qkp.21.1705615311383; Thu, 18 Jan 2024 14:01:51 -0800 (PST) ARC-Seal: i=2; a=rsa-sha256; t=1705615311; cv=pass; d=google.com; s=arc-20160816; b=EYf8ZiFIo3oan9rn5B7zHkRb4BWuUc8ftcAAZHEJAIaWl7+pwao2JtSjOZxFjwiMy6 VzOD4Pt94x6b7ttjYjw3ubDklOwSnNBblfOeki7h+WOyoImFWTZMocBmFz7zl7aT3n3/ WPEG0pO/PbqpCiaDvKF2o7uJRs03JlhfQ6ZsSYqUU6eEs9DOS65Zb+ZL6hHRWTARbepo iQyl3PEmbzKp8lX0kXPmP592PSUQiRtVDT3qIV990k9n3rgdz8E3ZnwnUJYWNQBa8ChJ DLUjOcqJZlBVbPIimEZ5mPzvtwt4PGQBhOLZGpn8OUEHhNdUBqH+KHxHQlQxb143Xdve naxA== ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:in-reply-to:autocrypt:from:references:cc :to:content-language:subject:user-agent:mime-version :list-unsubscribe:list-subscribe:list-id:precedence:date:message-id :dkim-signature; bh=wWRDK/4ZzaT31PsFrzVKlomvAFq3jsvHArf9wpsCBM0=; fh=iC7baX6J/RRP0roI9y+fSGKJEWFOjnGkn3svuB3HBoI=; b=fIW8UjX+gqezPN6N0XaYggbpPJNq1NXr7DBYWbydvI1ngzODPG3Uk6wXw/a433OCC+ pIGvAZWgytJWCctsWcSAJZXyLjdZuAvM+Wp1LHmdQFgBTRBJ8c1K5KMuzFO6Kw9xZDVV pOOQq/8lpL0V6b42QnNqlUF6RagdX6u2JdYFj1190BNApHst9eUemVt/pa3Xj/g3If+M F8a7M7xvrUMVMQ69MB7X1Kh7AdXrng87oZgZJ2zjhOTceVM0qTRVR3VtSsQCOv9oe13L HeBL3CYUeehHkou4jrqnLkOTe9gCep2nXSL7VxDaUssMplEyBS4N5wBRS4PpyiWWgCCV tZwg== ARC-Authentication-Results: i=2; mx.google.com; dkim=pass header.i=@intel.com header.s=Intel header.b=QnEgnSEL; arc=pass (i=1 spf=pass spfdomain=intel.com dkim=pass dkdomain=intel.com dmarc=pass fromdomain=intel.com); spf=pass (google.com: domain of linux-kernel+bounces-30591-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.199.223 as permitted sender) smtp.mailfrom="linux-kernel+bounces-30591-linux.lists.archive=gmail.com@vger.kernel.org"; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=intel.com Return-Path: Received: from ny.mirrors.kernel.org (ny.mirrors.kernel.org. [147.75.199.223]) by mx.google.com with ESMTPS id vq22-20020a05620a559600b00783139dd015si14715391qkn.604.2024.01.18.14.01.51 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 18 Jan 2024 14:01:51 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel+bounces-30591-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.199.223 as permitted sender) client-ip=147.75.199.223; Authentication-Results: mx.google.com; dkim=pass header.i=@intel.com header.s=Intel header.b=QnEgnSEL; arc=pass (i=1 spf=pass spfdomain=intel.com dkim=pass dkdomain=intel.com dmarc=pass fromdomain=intel.com); spf=pass (google.com: domain of linux-kernel+bounces-30591-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.199.223 as permitted sender) smtp.mailfrom="linux-kernel+bounces-30591-linux.lists.archive=gmail.com@vger.kernel.org"; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=intel.com Received: from smtp.subspace.kernel.org (wormhole.subspace.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ny.mirrors.kernel.org (Postfix) with ESMTPS id 28A331C231F6 for ; Thu, 18 Jan 2024 22:01:51 +0000 (UTC) Received: from localhost.localdomain (localhost.localdomain [127.0.0.1]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 5302A328A7; Thu, 18 Jan 2024 22:01:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="QnEgnSEL" Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.11]) (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 C0F5E321BA for ; Thu, 18 Jan 2024 22:01:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.11 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705615293; cv=none; b=OLhX255b446uTu/R64xe6dfId+h2nGK+KlIXi98LBCcYRCOZOKIGdkK0lFmgFdq2ow6Sbz31ivuUChdTa9bw4JE0BiRN4EvoTP0nLVsC8BAKftiyWPslPheiDNd1Ai8LqGljpaEpYyHA7uYPTocroMauDGQ3GhtTodYrdDaKhvs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705615293; c=relaxed/simple; bh=1l2k0DCIGCSpNoESefovU5y1nH2h9QDA2SjwEwTldHA=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=XvfqtYYeWNtrwRn1amSsHCiRf1MCaq6cE1qz/nVSip5vON9P3pbioK898Gf+oXAfVkw2oOsHegIhc9ngaUpEeaX/Dlkh8rvohc0a/BZI7cbqJEicfFvHRkgQI8pnejSuVs645GlA9znOg76TgR2aIkNytNF0UPcjg5mfvhfSCTg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=QnEgnSEL; arc=none smtp.client-ip=198.175.65.11 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1705615292; x=1737151292; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=1l2k0DCIGCSpNoESefovU5y1nH2h9QDA2SjwEwTldHA=; b=QnEgnSELJsIxXWqRzS4HGlPZiKnJtZrbHvPtf5Cl6WMiDkVceNPCqsFW 48peYUTMCJW+WIXfw9j/0Kl+BS+nBAzmgffm2bbFscU31SpRWEsRS/Z6s Gtb3tNuSu+XZ694bIMT/ZpKYRH9BrMNI06j2aMfqkvT02B5BJrOx4tyFb YblaP0EeuMuLjCjrtmZZzs4CqFMVg9nguf1BBpM1XpLzJFIU6rSlBNwxD PKojG1ZZVcBDBRZRgXSIZ7goALjK+Woumem+cEYjGJ8AN4Cz6YkKp6Nyq gyrC1YbHA+kosII4nw3sMgZyB4ooJyQ/I+xJNjC+M30hRGbNys5z0R1WZ g==; X-IronPort-AV: E=McAfee;i="6600,9927,10956"; a="7280835" X-IronPort-AV: E=Sophos;i="6.05,203,1701158400"; d="scan'208";a="7280835" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orvoesa103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Jan 2024 14:01:31 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10956"; a="818893221" X-IronPort-AV: E=Sophos;i="6.05,203,1701158400"; d="scan'208";a="818893221" Received: from dfast-mobl.amr.corp.intel.com (HELO [10.251.13.41]) ([10.251.13.41]) by orsmga001-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Jan 2024 14:01:30 -0800 Message-ID: <5bddbb34-4081-494b-8c12-c2e70898a608@intel.com> Date: Thu, 18 Jan 2024 14:02:08 -0800 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] x86/fpu: verify xstate buffer size according with requested features Content-Language: en-US To: Thomas Gleixner , Andrei Vagin Cc: Andrei Vagin , Ingo Molnar , Borislav Petkov , Dave Hansen , LKML , x86@kernel.org, "H. Peter Anvin" References: <20240116234901.3238852-1-avagin@google.com> <30cd0be4-705f-4d63-bdad-fc57301e7eda@intel.com> <54bcb902-0fab-4a53-8b8e-85b6e4484b03@intel.com> <87cytyfmd8.ffs@tglx> 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: <87cytyfmd8.ffs@tglx> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 1/18/24 11:54, Thomas Gleixner wrote: > On Thu, Jan 18 2024 at 10:27, Dave Hansen wrote: >> If we have nice, reliable fault handling and then decide that we've got >> XRSTOR's running amok reading random memory all over the place that need >> a nicer error message, then we can add that code to predict the future. >> If our "predict the future" code goes wrong, then we lose an error >> message -- not a big deal. > After staring more at it, it's arguable to pass fpstate->user_size to > fault_in_readable() and ignore fx_sw->xstate_size completely. > > That's a guaranteed to be reliable size which prevents endless loops > because arguably that's the maximum size which can be touched by XRSTOR, > no? I like it. It takes fx_sw completely out of the picture, which was the root of the problem in the first place.