From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.19]) (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 433AF1AAE28 for ; Thu, 12 Dec 2024 21:18:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.19 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734038301; cv=none; b=tjNJ3NoTCwSuKhunaHBOpWT4p5/rlrkCAB2eqPYVSPbGoLeWVUyBX7PPQShd7NPBDk9MyRn5ZMr/xvHUPMQa1r2Wr87moVB+h4dTeulDBnBkW0T0kuY5JW0qWPQp/zNhyz7qDeWXzv0B7EZZxWMqqyisiW4vuxJQUNrKep2O+cM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734038301; c=relaxed/simple; bh=f5ACnRexztK7l9ld99nnyP9ovl7Hc7HhsC6nVgy4KoY=; h=Content-Type:Message-ID:Date:MIME-Version:Subject:To:Cc: References:From:In-Reply-To; b=BrrvAuzRBXivCpDmzkAJ7vNxNVN2W7xHg6ieNjvTuaK4NVJb8X0r21CjKKEyIcesJVWxo1wUp60ZQrczUFoojnBS6iUf7YmNw14S8038M9jmsNtRCvWxJ6GtiWfl0Lxnh1+eNi2jm6BkjE2BLlpIs/WzCmsWPFCciEKQUa0KXoA= 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=ZEPNuBDJ; arc=none smtp.client-ip=192.198.163.19 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 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="ZEPNuBDJ" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1734038300; x=1765574300; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to; bh=f5ACnRexztK7l9ld99nnyP9ovl7Hc7HhsC6nVgy4KoY=; b=ZEPNuBDJS8YgN4IIeXZA8dRers0HhFz7/nlGJ8NJhZHMYZ98EUMQRFO+ 5Rsyt1JHMvwMYeNqr9vzn2zMcd/lQ2jpooru7N6YwclZWo+poxWVTGLrK XJBMjFO8FXLuhbiDqrUGY7FA1x95Ck43+OMuqSsY96fSo17UIQA+NWib6 1yQu5c50lA5RcUyiG/5iZSxKZNJWKmLn5PYyJbHg29S6stAE2s13XhkzG Y2z6mCqWmXNefbb4QJLc7be5OncvmunANWjKjhYykrRPdyBL0FdAVxwmh FDLWgwXDyqYs9OrAwYQpTncLWENknNYJqewqf3oANR0pFbj3OSYRGh9eJ Q==; X-CSE-ConnectionGUID: j8CZo+/eSp2+lfxw8dFPbg== X-CSE-MsgGUID: VQCrvR+fQKCdU/sNWhzJAA== X-IronPort-AV: E=McAfee;i="6700,10204,11284"; a="33784141" X-IronPort-AV: E=Sophos;i="6.12,229,1728975600"; d="scan'208";a="33784141" Received: from orviesa004.jf.intel.com ([10.64.159.144]) by fmvoesa113.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Dec 2024 13:18:20 -0800 X-CSE-ConnectionGUID: uS/bY5rLQAi0T4BJtOq2gA== X-CSE-MsgGUID: H85enkTyQ6aRaXBgOeRBOQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.12,229,1728975600"; d="scan'208";a="101375786" Received: from ccbilbre-mobl3.amr.corp.intel.com (HELO [10.124.223.26]) ([10.124.223.26]) by orviesa004-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Dec 2024 13:18:19 -0800 Content-Type: multipart/mixed; boundary="------------OxHzUR6N6tQ0toSbMptMxSQY" Message-ID: <4517cb69-3c5c-4e75-8a14-dab136b29c19@intel.com> Date: Thu, 12 Dec 2024 13:18:10 -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/kexec: Only write through identity mapping of control page To: David Woodhouse , Nathan Chancellor Cc: "Ning, Hongyu" , kexec@lists.infradead.org, Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , "Kirill A. Shutemov" , Kai Huang , Nikolay Borisov , linux-kernel@vger.kernel.org, Simon Horman , Dave Young , Peter Zijlstra , jpoimboe@kernel.org, bsz@amazon.de References: <20241205153343.3275139-1-dwmw2@infradead.org> <20241205153343.3275139-14-dwmw2@infradead.org> <20241212014418.GA532802@ax162> <10a4058d9a667ca7aef7e1862375c2da84ef53a3.camel@infradead.org> <20241212150408.GA542727@ax162> <38aaf87162d10c79b3d3ecae38df99e89ad16fce.camel@infradead.org> <20241212174243.GA2149156@ax162> <9c68688625f409104b16164da30aa6d3eb494e5d.camel@infradead.org> From: Dave Hansen Content-Language: en-US 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: <9c68688625f409104b16164da30aa6d3eb494e5d.camel@infradead.org> This is a multi-part message in MIME format. --------------OxHzUR6N6tQ0toSbMptMxSQY Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 12/12/24 12:11, David Woodhouse wrote: > From: David Woodhouse > > The virtual mapping of the control page may have been _PAGE_GLOBAL and > thus its PTE might not have been flushed on the %cr3 switch and it might > effectively still be read-only. Move the writes to it down into the > identity_mapped() function where the same %rip-relative addressing will > get the new mapping. > > The stack is fine, as that's using the identity mapped address anyway. Shouldn't we also ensure that Global entries don't bite anyone else? Something like the completely untested attached patch? --------------OxHzUR6N6tQ0toSbMptMxSQY Content-Type: text/x-patch; charset=UTF-8; name="pge.patch" Content-Disposition: attachment; filename="pge.patch" Content-Transfer-Encoding: base64 ZGlmZiAtLWdpdCBhL2FyY2gveDg2L2tlcm5lbC9yZWxvY2F0ZV9rZXJuZWxfNjQuUyBiL2Fy Y2gveDg2L2tlcm5lbC9yZWxvY2F0ZV9rZXJuZWxfNjQuUwppbmRleCBlOWU4OGMzNDJmNzUy Li5lY2JkNzdhYWIxMjIxIDEwMDY0NAotLS0gYS9hcmNoL3g4Ni9rZXJuZWwvcmVsb2NhdGVf a2VybmVsXzY0LlMKKysrIGIvYXJjaC94ODYva2VybmVsL3JlbG9jYXRlX2tlcm5lbF82NC5T CkBAIC0xNTUsNiArMTU1LDggQEAgU1lNX0NPREVfU1RBUlRfTE9DQUxfTk9BTElHTihpZGVu dGl0eV9tYXBwZWQpCiAJICovCiAJYW5kbAkkKFg4Nl9DUjRfUEFFIHwgWDg2X0NSNF9MQTU3 KSwgJXIxM2QKIAlBTFRFUk5BVElWRSAiIiwgX19zdHJpbmdpZnkob3JsICRYODZfQ1I0X01D RSwgJXIxM2QpLCBYODZfRkVBVFVSRV9URFhfR1VFU1QKKwkvKiBJbnZhbGlkYXRlIEdsb2Jh bCBlbnRyaWVzIGZyb20gdGhlIFRMQjogKi8KKwlhbmRxCSR+KFg4Nl9DUjBfUEdFKSwgJXIx M2QKIAltb3ZxCSVyMTMsICVjcjQKIAogCS8qIEZsdXNoIHRoZSBUTEIgKG5lZWRlZD8pICov Cg== --------------OxHzUR6N6tQ0toSbMptMxSQY--