From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 08C5AC77B7F for ; Mon, 23 Jun 2025 10:22:20 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 905A46B00BA; Mon, 23 Jun 2025 06:22:20 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 8DCEC6B00BB; Mon, 23 Jun 2025 06:22:20 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7F2B36B00BD; Mon, 23 Jun 2025 06:22:20 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 662656B00BA for ; Mon, 23 Jun 2025 06:22:20 -0400 (EDT) Received: from smtpin22.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 0735B59C28 for ; Mon, 23 Jun 2025 10:22:20 +0000 (UTC) X-FDA: 83586275640.22.A1840C7 Received: from mail.alien8.de (mail.alien8.de [65.109.113.108]) by imf28.hostedemail.com (Postfix) with ESMTP id 6FCE8C0016 for ; Mon, 23 Jun 2025 10:22:17 +0000 (UTC) Authentication-Results: imf28.hostedemail.com; dkim=pass header.d=alien8.de header.s=alien8 header.b="HbQHWs/l"; dmarc=pass (policy=none) header.from=alien8.de; spf=pass (imf28.hostedemail.com: domain of bp@alien8.de designates 65.109.113.108 as permitted sender) smtp.mailfrom=bp@alien8.de ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1750674138; a=rsa-sha256; cv=none; b=Eu65GnYoeneJMykRVQ540gpelX7Idt6fgIoYDOyLeWizvYes/yFPxVgyTWJlP8vF8IrzKo 3TBMvXIirEPtGcAUZFpp81XNKP3fUposj9KFYALbTraDmMcrKJI1TOcZqe50Us7IA56U6h PBeguh5zu4g4cP8mP14FwLg5/wxKeZo= ARC-Authentication-Results: i=1; imf28.hostedemail.com; dkim=pass header.d=alien8.de header.s=alien8 header.b="HbQHWs/l"; dmarc=pass (policy=none) header.from=alien8.de; spf=pass (imf28.hostedemail.com: domain of bp@alien8.de designates 65.109.113.108 as permitted sender) smtp.mailfrom=bp@alien8.de ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1750674138; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=bit8kbTV4D3YTiOYptKHmiW7XfvgF+MCkFLAQajwdzk=; b=ls+SRojHQXVI2In3F3Ekbw7J/d/UhkDx855iEBvvFHKYEKsnhMqZEuXM+tmNyLvUWto3I0 U5KKttkUHOcU8rJAPS7wAmAg1FVOIjfXzljCRKlZTfzu5sEcEjUI0C9vtQOj9KDz90OtVW JuSeJdkWTJEcd6//65mC0DKiE0EzOw8= Received: from localhost (localhost.localdomain [127.0.0.1]) by mail.alien8.de (SuperMail on ZX Spectrum 128k) with ESMTP id 6633040E019C; Mon, 23 Jun 2025 10:22:13 +0000 (UTC) X-Virus-Scanned: Debian amavisd-new at mail.alien8.de Received: from mail.alien8.de ([127.0.0.1]) by localhost (mail.alien8.de [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id X3JkVTcSfEkT; Mon, 23 Jun 2025 10:22:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=alien8; t=1750674123; bh=bit8kbTV4D3YTiOYptKHmiW7XfvgF+MCkFLAQajwdzk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=HbQHWs/ls8gZcfaGZhZv31VGHo7gwnSdUS6tcGx5ju6fZNZNY7nrxFpxNwZjLu2Oh XS7v/Ipqm7R5Gt4bJzO3gvfy9+TK/sEn4+UhrNhM2kODyyMDVofQNtyFmoAmi4pUvu 7Bof7QehSI7Qhhp6CaQIgBS2XBwOGZTRQHy9D3jF2xfNhlFkQphtrKTYysOrLuQlcd 5DZW3HGSwtZej+UmB3Q7HkqF9IHfDm5nYLDrrCzgOrASUWqXO4WHmmFy2xLrJ3Y4LB +J9SiPoSMBzFfPPuo/wXAZzC1UYbclUgVJJV0P+iFAo0GOH9d0cw3TvPC97R/QbMe+ kfoFG7keh2xnoyupNaPcs/pZm2+ZEEFNlcrVOP07MwYrwdVqsTN++R93nArt0KvMOY ydmbpOUhFb7ypo+ObodoI3r5FfJABlmwGtjNbrPsgjLll9uf+hsXla0XB1hZesRsII 0eAaH/vcQNEBsfbaHJk/dOvuGpSfecQHK5l+IqHnYT4NReLwCFb8yC7BhdFDlja4sv s4a0Hdz4FbszW8nVDNGvy3o+s+gonkxnzBWmVYIyqizfNXpKKqigDzu+ChQ2Na2PP+ ToXCf8yvBgwWs7vd0+P4AcRe9tvgUAkqSUj/RpcQUgLU50z0XqT5EuTjBVWrshIEVU ciO9IULS86WrYB8ItxO4v1dc= Received: from zn.tnic (p57969c58.dip0.t-ipconnect.de [87.150.156.88]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature ECDSA (P-256) server-digest SHA256) (No client certificate requested) by mail.alien8.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id D19B440E01A0; Mon, 23 Jun 2025 10:21:10 +0000 (UTC) Date: Mon, 23 Jun 2025 12:21:05 +0200 From: Borislav Petkov To: "Kirill A. Shutemov" Cc: Andy Lutomirski , Thomas Gleixner , Ingo Molnar , 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 , Alexey Kardashevskiy , Alexander Shishkin , 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, linux-mm@kvack.org, Yian Chen Subject: Re: [PATCHv6 01/16] x86/cpu: Enumerate the LASS feature bits Message-ID: <20250623102105.GCaFkqkatFSbyl1YeN@fat_crate.local> References: <20250620135325.3300848-1-kirill.shutemov@linux.intel.com> <20250620135325.3300848-2-kirill.shutemov@linux.intel.com> <20250620163504.GCaFWNuI-8QFqAM0yI@fat_crate.local> <6y2iqv6c2idn7yebaec7tyhzl5zcsrwqq4lcsokumlqeophzaf@ljnmxorblgcj> <20250620182943.GDaFWolxhwogB2tTxb@fat_crate.local> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: 6FCE8C0016 X-Stat-Signature: 3h7bx5c79iz8ih8h4m7t97dbgfctz8qt X-Rspam-User: X-HE-Tag: 1750674137-625397 X-HE-Meta: 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 5qk0O/9K RPL6TTsMG7tnnxYeDOOVBAIKAAAaR93QD7oWRkHOzFMQAJtYLHbLNziDDgtJt5iirUF6LqLCFsouphv2wCviU3xddp1UHpHR1Bb6Rx0LTQ5nhk3ABY6+/WQd7MgP/tuTWY3anWgC1DWk/EafI+CBviJiWgbsM5lyPlQgC8NrPKfqtsuvhlEuVcxxh3zfEf76YpEnz8o9dfHegMl/PU3VUsvQbdvl5zcaMZm7I21GcKmiVgaTXB9CkoZr1lxMAZKjKlmuQSsMVDYx3i5MJMJ8fkJVOd832UoUp3ojdMgwjYm8CTTVyer83Z5YJgZyI/aPstI4LhznZQKeUOQKwTuu4oxNuUEAiXVAn9z5l X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Mon, Jun 23, 2025 at 11:17:02AM +0300, Kirill A. Shutemov wrote: > What about this: > > LASS provides protection against a class of speculative attacks, such as > SLAM[1]. Add the "lass" flag to /proc/cpuinfo to indicate that the feature > is supported by hardware and enabled by the kernel. This allows userspace > to determine if the setup is secure against such attacks. Yeah, thanks. I'm still not fully on board with userspace determining whether they're mitigated or not but that's a general problem with our mitigations. Also, I haven't looked at the patchset yet but I think it should be also adding code to bugs.c to make all those vulns which it addresses, report that they're mitigated by LASS now in grep -r . /sys/devices/system/cpu/vulnerabilities/ output. Which makes your cpuinfo flag not really needed as we already have a special method for the mitigations reporting. But ok, it has gotten kernel enablement so stating so in cpuinfo is ok. Thx. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette