From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.zytor.com (terminus.zytor.com [198.137.202.136]) (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 712C0375AB2 for ; Sat, 4 Jul 2026 18:53:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.136 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783191188; cv=none; b=ir8xg0izax966MLxvpGoPbsH9W4LmkFBDkIrgmAvByobsUaRlvLgqI09EFOfN4pNSIWGKjpy96M4H1/cGIsJZYhijgFlSFCkDiOIqG3WedVIhNAkTx/2l47NHNfcZW08p0btY7ok7vPX+leYarX33XPYrttS9Vjh+QLgvY6sFVY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783191188; c=relaxed/simple; bh=SR+4dycvLeCKLHdc2fn4h7aPvucD4jvAQM1x3jFB8vI=; h=Date:From:To:CC:Subject:In-Reply-To:References:Message-ID: MIME-Version:Content-Type; b=A8o6Qkj82Qa8U/6eGHSgXH2z8geG5jDINFXG2Q0/9uwxkNkurgsBkFJ1ihkpfjRyUbEcOYDMiZFDIfxKGxyqvnoFzjdzAklAEaS9zrwg42W1GSLWgHi7BNJ8/F0gtPJMhZQ61gqkwnsqu/Js7ES6dnY12a0Xge8PCQPKk4P1SKk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com; spf=pass smtp.mailfrom=zytor.com; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b=EuwrDyHm; arc=none smtp.client-ip=198.137.202.136 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=zytor.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b="EuwrDyHm" Received: from ehlo.thunderbird.net (c-76-133-66-138.hsd1.ca.comcast.net [76.133.66.138]) (authenticated bits=0) by mail.zytor.com (8.18.1/8.17.1) with ESMTPSA id 664IqK7D1891567 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NO); Sat, 4 Jul 2026 11:52:20 -0700 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.zytor.com 664IqK7D1891567 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2026062701; t=1783191141; bh=NFIoOWfzZMcyBQ19fWQ7c+pDePPLIo6I4EJEU1IDUTk=; h=Date:From:To:CC:Subject:In-Reply-To:References:From; b=EuwrDyHm8PBj/im2GkGeOhn73pbSbgL0VexAiPpYQ4ZtK4ziM9HQ39jcFBIF2ph1t NJVeRj8uaUbzVjy3Z8tfBE2F8uYewlfmp8NxWkWwLOR/omV4aCQEHlHu93m0HOcuoj EYS1ZnomjP38DNM3NHRSXj23Lnw7+5bMg2rTv5YJjyfDqiXIPDXHCABLh4P9aTB2Uz WcuwI+C212OHAXpXpwx1lgu9ANEs1xnsK9NCsmsuzjYnaE6jDDS1Sf8MTtF0G5TE9E 2KBCdBQRa4AS9Xn+LELIFrsoE3zJ37eicMqmbjU8nSA2lJx5U/u/OHdpGaswoQd0sJ 1uCPn8OVIv6aQ== Date: Sat, 04 Jul 2026 11:52:14 -0700 From: "H. Peter Anvin" To: Borislav Petkov , Evalyn Goemer , dave.hansen@linux.intel.com CC: ludloff@gmail.com, linux-kernel@vger.kernel.org, tglx@kernel.org, mingo@redhat.com, x86@kernel.org, joe@perches.com, Andrew Cooper Subject: =?US-ASCII?Q?Re=3A_=5BPATCH=5D_platform/x86=3A_handle_Intel?= =?US-ASCII?Q?_CPUs_falsely_reporting_as_GenuineIotel?= User-Agent: K-9 Mail for Android In-Reply-To: <20260704182952.GAaklRINnc6XDFoGcE@fat_crate.local> References: <31nKPXtCQwaVciQ3mSoYDQ@evalyngoemer.com> <20260704182952.GAaklRINnc6XDFoGcE@fat_crate.local> Message-ID: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On July 4, 2026 11:29:52 AM PDT, Borislav Petkov wrote: >On Sat, Jul 04, 2026 at 02:15:02PM -0400, Evalyn Goemer wrote: >> > Overall, it's an outlier, and I'd flag such systems, not placate them= =2E >>=20 >> Yeah it's a very strange thing I have found and thought could be worth= =20 >> handling=2E I ended up making the patch this way since this is the only= case of=20 >> this I could see as well other codebases online handled it similarly=2E > >Well, Sashiko pointed out a couple more places: > >https://sashiko=2Edev/#/patchset/20260704025147=2E585133-1-git%40evalyngo= emer=2Ecom > >which would need to be taken care of too=2E > >But I tend to agree with Christian and even go a step further - completel= y >stop booting on them=2E Because who knows what else has been tampered wit= h in >them=2E > >Yeah, yeah, bit flips, sure, but a system which generates bit flips relia= bly >gets its DRAM replaced so why should we treat this thing differently=2E= =2E=2E > >Let's see what Intel folks say here too=2E > To tell you the truth this is literally the first time I have heard of thi= s at all!=20 At the very least we should taint these as CPU_OUT_OF_SPEC=2E It doesn't s= eem like a bad idea either to halt *by default*=2E I would like to see a command line option to override that behavior, thoug= h=2E Heck, an x86=2Ecpu_vendor=3D command line option might be usef= ul for debugging in general=2E