From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.11]) (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 EEF0917DFF1; Mon, 28 Oct 2024 22:00:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.11 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730152854; cv=none; b=Uv8hFyaSeJtQOQOV8CZ2cAof0FVgxxCk8PMMPJ25LC69eCgWc6MJVSGitZoIbr5IvihUDUSd8GM3R0kPt8P/57ILkCUOCkILPyquHmQCQv807MTHljfwadWXuIjOdbdpPbvAp+mNmPAWDHRYbSV3Lz5Cxswl6bnTo4o6Q0Yc87k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730152854; c=relaxed/simple; bh=J0cj6572cT41BEImfr7FQU44fU/3kuMbptIfwmfZeMs=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=A32lPSX6+bVWz+5ZSWBMZSUdjitr/t8PXssiJKcvppgyXbSjfaZ0Hod3/IasMz9pc8Ku/lPlvfjCp0meQjsEG7/+4pfgbYB9SyJzRpCq8Bn+aRt+7LjD0SNgagxyEriF4gbfK9dID2UKJYHbRq44Ta81alG8Bc0yEPj5jjqVs5g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=Pr5s7lsV; arc=none smtp.client-ip=192.198.163.11 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="Pr5s7lsV" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1730152852; x=1761688852; h=from:to:cc:subject:in-reply-to:references:date: message-id:mime-version; bh=J0cj6572cT41BEImfr7FQU44fU/3kuMbptIfwmfZeMs=; b=Pr5s7lsVtqP3DHyakmiDWupMk13GAFvmWs+duOrjWwEiEWcUPb1b8VmU bua5V2HaZivJwPJTQ26fyt2bVh2EoBSI58QTVgS2F/P7OJQdfKkA2Dozq FrqkAq7lxkgT7DN3skAjmu3OvpaOS5XpjZMIXv77Hh5r28DGrE4oAqPkM mG6gys92Auxv7FWKweOSZ/bLZEU3aqVftJw1nG4RYGuT+Zd9zeOepbjWL jw95qAjGn6uxAAoNHjPWCbgR3LGdcjPt9zObkS7sXm4AHRXfdqPmnNXb/ Hf5Li8utiTYtKFEHfDsc5S05dhUhnvEge/9Hil+7zaWp/C49I5M31jeIA g==; X-CSE-ConnectionGUID: 9lt0vBrlQy2K8NWUXLHePQ== X-CSE-MsgGUID: 9nSb9x7yT4O2kfdm55BcLQ== X-IronPort-AV: E=McAfee;i="6700,10204,11239"; a="40347782" X-IronPort-AV: E=Sophos;i="6.11,240,1725346800"; d="scan'208";a="40347782" Received: from orviesa005.jf.intel.com ([10.64.159.145]) by fmvoesa105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Oct 2024 15:00:51 -0700 X-CSE-ConnectionGUID: O2pVeB6cQBqhdhUJbCUfWg== X-CSE-MsgGUID: qf9XLHZ/SseSNwdSQW5EgA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.11,240,1725346800"; d="scan'208";a="86541125" Received: from ubik.fi.intel.com (HELO localhost) ([10.237.72.184]) by orviesa005.jf.intel.com with ESMTP; 28 Oct 2024 15:00:39 -0700 From: Alexander Shishkin To: "Kirill A. Shutemov" Cc: Andy Lutomirski , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Peter Zijlstra , Ard Biesheuvel , "Paul E. McKenney" , Josh Poimboeuf , Xiongwei Song , Xin Li , "Mike Rapoport (IBM)" , Brijesh Singh , Michael Roth , Tony Luck , "Kirill A. Shutemov" , Alexey Kardashevskiy , Jonathan Corbet , Sohil Mehta , Ingo Molnar , Pawan Gupta , Daniel Sneddon , Kai Huang , Sandipan Das , Breno Leitao , Rick Edgecombe , Alexei Starovoitov , Hou Tao , Juergen Gross , Vegard Nossum , Kees Cook , Eric Biggers , Jason Gunthorpe , "Masami Hiramatsu (Google)" , Andrew Morton , Luis Chamberlain , Yuntao Wang , Rasmus Villemoes , Christophe Leroy , Tejun Heo , Changbin Du , Huang Shijie , Geert Uytterhoeven , Namhyung Kim , Arnaldo Carvalho de Melo , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-efi@vger.kernel.org, alexander.shishkin@linux.intel.com Subject: Re: [PATCH v5 16/16] Revert "x86/lam: Disable ADDRESS_MASKING in most cases" In-Reply-To: References: <20241028160917.1380714-1-alexander.shishkin@linux.intel.com> <20241028160917.1380714-17-alexander.shishkin@linux.intel.com> Date: Tue, 29 Oct 2024 00:00:38 +0200 Message-ID: <87sesfubuh.fsf@ubik.fi.intel.com> Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain "Kirill A. Shutemov" writes: > On Mon, Oct 28, 2024 at 06:08:04PM +0200, Alexander Shishkin wrote: >> This reverts commit 3267cb6d3a174ff83d6287dcd5b0047bbd912452. >> >> LASS mitigates the Spectre based on LAM (SLAM) [1] and an earlier >> commit made LAM depend on LASS, so we no longer need to disable LAM at >> compile time, so revert the commit that disables LAM. >> >> [1] https://download.vusec.net/papers/slam_sp24.pdf >> >> Signed-off-by: Alexander Shishkin >> CC: Pawan Gupta > > Before re-enabling LAM, you need to uncomment X86_FEATURE_LAM check in > arch/x86/kernel/cpu/common.c introduced in recent 86e6b1547b3d ("x86: fix > user address masking non-canonical speculation issue"). Forgot about that one. Thanks! Regards, -- Alex