From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lists.gentoo.org (pigeon.gentoo.org [208.92.234.80]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by finch.gentoo.org (Postfix) with ESMTPS id 896ED1382C5 for ; Thu, 4 Jan 2018 16:18:52 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 082ACE0952; Thu, 4 Jan 2018 16:18:46 +0000 (UTC) Received: from mail-pl0-x231.google.com (mail-pl0-x231.google.com [IPv6:2607:f8b0:400e:c01::231]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by pigeon.gentoo.org (Postfix) with ESMTPS id 96485E093E for ; Thu, 4 Jan 2018 16:18:45 +0000 (UTC) Received: by mail-pl0-x231.google.com with SMTP id z5so1282078plo.10 for ; Thu, 04 Jan 2018 08:18:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:sender:in-reply-to:references:from:date:message-id :subject:to; bh=OehZ5FWbbR4BnP/kXMGeYC3ssNO7EJezsjJ+Gda1plY=; b=rRh6cQpj2XflCuw3GS3M/liOSV6NB/Y+d7Am+mCpq8E/Ghw/cYc6HC6GYjrWd2J1P5 U0jWnmg4Xp49F3TUscYKiIoY1fFRaUEG0UwYA6CHPP9dqZ+Ew99XlVgXWCezFQWzx5D/ s8lQfYluf6GZiPY/T+q8EkhPAPkfullYV56Dr8MR0sGL+zZEylg8tQXBvfC9lC7k9Hcn lMYfjwBPcXLHmwn0ZhQDj/VGFJXJk+Mmih6BNgJ+4UC1Q6sIWVtM0FZnZH/7yLeVcpVd s+LPhnRnYhUPgirzXeoSczQuOH8g/ZPT4MtHC/QgaEkFnzsJIN45ZI8SciAZWoCCPS3N AULg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:sender:in-reply-to:references:from :date:message-id:subject:to; bh=OehZ5FWbbR4BnP/kXMGeYC3ssNO7EJezsjJ+Gda1plY=; b=WXTrh4/c8BcQ9J/w6knNlkX5IQIWB3WFy9qgQHyo00UU4CaV+eXDUXwAFDxsDbroXZ eTozdLBckXOgRMi4J8d4Rkt7V5oB3WAXuem6h09lzj/phMXQP4wJhjJflyffTup/mFIA YSyGUN/qR0s56yw4lzN5C5OnbiWNlHjWg/UUZtxJc0paPk1aRBkj+T4qLppFXcM+LFyb 2GFC9LpK004RSGYTM4BnRK0zRGHs4oy3U7RaOfxihrJnDmIzA4fIHjGj7/7OdE+SCPFA T6VUCTcKYG+KMbWYU8rul5Q7CF9RK3FoYI1+t3tej6OrsRnIILccrvgUXPMV3SxHd9UY EEzA== X-Gm-Message-State: AKGB3mKSS1UYaCGxauiUkBYur5gXmlh9zGmIAq3lvx3l/QD1KgBAGD0J qaLkmUkzpRDXpc/3GX+AM7OEUpFxmrS2GTNvHkoozDCv X-Google-Smtp-Source: ACJfBouiEi9jRbLyKs7mMh83EKJj0zNi6XeSWxO1mJ0UYJApR9svMxQRmwu4ONyhr+yvaG3ycGwym31AFdffpb1jQC4= X-Received: by 10.84.251.143 with SMTP id w15mr66078pll.221.1515082724343; Thu, 04 Jan 2018 08:18:44 -0800 (PST) Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org MIME-Version: 1.0 Sender: freemanrich@gmail.com Received: by 10.100.151.169 with HTTP; Thu, 4 Jan 2018 08:18:43 -0800 (PST) In-Reply-To: References: <92ab5d0f-6111-cdec-5443-4f0cb0712eaf@charter.net> From: Rich Freeman Date: Thu, 4 Jan 2018 11:18:43 -0500 X-Google-Sender-Auth: n_ZwiK0DV4BncZSnzMXlbWBIRpA Message-ID: Subject: Re: [gentoo-user] Expect a ~15% average slowdown if you use an Intel processor To: gentoo-user@lists.gentoo.org Content-Type: text/plain; charset="UTF-8" X-Archives-Salt: 17ee28a3-44c2-492d-8a4e-d2b642333787 X-Archives-Hash: 921ed18a30bcb9e9a566e0cd382a619b On Thu, Jan 4, 2018 at 10:44 AM, R0b0t1 wrote: > > I am still working through the information myself, but it looks like > BPF filters are an easy way to make sure you have something to look > for in kernelspace. My understanding is that for exploit 1 to work you need to have the kernel execute some code for you, and BPF is a way to do that because it is a JIT compiler. The bits about finding where BPF is in kernelspace is for exploit 2, which requires branching into that code, which requires knowing its address. > On Thu, Jan 4, 2018 at 9:44 AM, R0b0t1 wrote: >> But, if they do, > > then AMD processors are susceptible in the same way, and the issue can > not be fixed. There are some news pieces and commenters claiming that > AMD processors suffer similar issues. AMD published this: https://www.amd.com/en/corporate/speculative-execution This tends to go along with Google's statement that AMD is vulnerable to variant 1, but not 2 or 3. There is plenty of speculation going on with the hazy info that was provided, but none of the original sources suggest that AMD is vulnerable to variant 3. For variants 1/2 Google says that AMD is susceptible to only 1, and the white paper says that they're vulnerable to either 1/2 but they don't say which specifically. In any case, short of somebody publishing actual exploit code so that people can run their own tests, I'm going to go with AMD. Nobody reputable is outright contradicting their statements. For variant 1 the only known vulnerability is BPF which probably next to nobody uses, and for variant 2 there really aren't any alternatives available right now anyway. -- Rich