From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.14]) (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 3BF0D2405E4 for ; Fri, 21 Feb 2025 17:01:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.14 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740157263; cv=none; b=mlXDtMxUeAoskvaFg+eWJ9CQlZSDZ7jc6WFeFnEtwMnhLORvBUHwcr0O0evw1SK5OOTM43fLKcTYA71VVHNGaxlEJaQUTth5VDMfWTKfMpS62UAljqnl/d2m7IUTHjge4yrslTWFA8ZZEIydXDRQHRrZfkS1VAehR2Xk3dNOe+0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740157263; c=relaxed/simple; bh=j+nR+337vj5+MRg/OUYVi4F6tWqvE2RTx8jtkTapEhE=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=hkmuIbpXlufaisFsJKre0+UND45+5nwCzNKSgZC0sYMu8H8rJGwAumlls8UYWVWs0XoWQILmKdM4paR0WcsBOa5de/wwEszmrpXbxiZ3lMrix47DAQnNyU4cGhJkKR5E7xytJ9iOQQVk05XA2vn+gTykarmbowU/s2gaAN2Q2Ms= 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=RtGRm0k7; arc=none smtp.client-ip=198.175.65.14 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="RtGRm0k7" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1740157263; x=1771693263; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=j+nR+337vj5+MRg/OUYVi4F6tWqvE2RTx8jtkTapEhE=; b=RtGRm0k7SBiAnfrEPuQVmuYAo7kTU/+8q/GhOLLhcP3UzK/pOUeR4Uc4 hu9tAbMOSUqYNMDjXxjSWsh7xQdsvNRpmPBNosSBpOxWbDbJfCyeSwCAT /vvDJR8ieDNZuCQxzuEVoGroEU5O2Kj+pU75RlSWjGyh7pIgDKX/PSCM9 msE9Uijn3wok/w+PZ5/DvGxdFmuUK1U+oUAezqHchlB4EOf9M63bXWVOe 4naXlWlDMeN0TOmVAwPACxZXmWJSRMOKV4udQCzy+vKkNNLE7LHOzO5jW 3EYOz34quKRIzW2Evyn79ePNkhGXpH7CHPU81WVZDQVTK52Lflqslv15f Q==; X-CSE-ConnectionGUID: DO/0L/z+SdeBRa2mNqNdVw== X-CSE-MsgGUID: GYVw2SrJTr6s7o1LNuDBng== X-IronPort-AV: E=McAfee;i="6700,10204,11352"; a="44765399" X-IronPort-AV: E=Sophos;i="6.13,305,1732608000"; d="scan'208";a="44765399" Received: from orviesa002.jf.intel.com ([10.64.159.142]) by orvoesa106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Feb 2025 09:01:02 -0800 X-CSE-ConnectionGUID: gMIxSY2/TiGO4+kTXeK1HA== X-CSE-MsgGUID: wO5gwcSXQzykwLKDKs5oOQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.13,305,1732608000"; d="scan'208";a="146261314" Received: from aschofie-mobl2.amr.corp.intel.com (HELO [10.125.110.177]) ([10.125.110.177]) by orviesa002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Feb 2025 09:01:01 -0800 Message-ID: <32af68b8-4280-4c15-8e5c-be807c282f94@intel.com> Date: Fri, 21 Feb 2025 09:01:03 -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 1/4] pkeys: add API to switch to permissive pkey register To: Dmitry Vyukov , mathieu.desnoyers@efficios.com, peterz@infradead.org, boqun.feng@gmail.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, aruna.ramakrishna@oracle.com, elver@google.com Cc: "Paul E. McKenney" , x86@kernel.org, linux-kernel@vger.kernel.org References: 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: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 2/17/25 03:07, Dmitry Vyukov wrote: ... > /* > * If more than 16 keys are ever supported, a thorough audit > * will be necessary to ensure that the types that store key > @@ -123,4 +125,16 @@ static inline int vma_pkey(struct vm_area_struct *vma) > return (vma->vm_flags & vma_pkey_mask) >> VM_PKEY_SHIFT; > } > > +typedef u32 pkey_reg_t; > + > +static inline pkey_reg_t switch_to_permissive_pkey_reg(void) > +{ > + return write_pkru(0); > +} Just a naming nit: the "switch_to" and "reg" parts of this don't quite parse for me. This is writing a _value_ to a register. Maybe: write_permissive_pkey_val() or set_permissive_pkey_val() would be a better name. > diff --git a/include/linux/pkeys.h b/include/linux/pkeys.h > index 86be8bf27b41b..d94a0ae7a784b 100644 > --- a/include/linux/pkeys.h > +++ b/include/linux/pkeys.h > @@ -48,4 +48,26 @@ static inline bool arch_pkeys_enabled(void) > > #endif /* ! CONFIG_ARCH_HAS_PKEYS */ > > +#ifndef CONFIG_ARCH_HAS_PERMISSIVE_PKEY > + > +/* > + * Common name for value of the register that controls access to PKEYs > + * (called differently on different arches: PKRU, POR, AMR). > + */ > +typedef int pkey_reg_t; Tiny nit: Should this be an unsigned type? Nobody should be manipulating it, but I'd be surprised if any of the architectures have a signed type for it.