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 X-Spam-Level: X-Spam-Status: No, score=-10.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,SUBJ_ALL_CAPS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F164EC433E0 for ; Mon, 11 Jan 2021 23:21:00 +0000 (UTC) Received: from lists.zx2c4.com (lists.zx2c4.com [165.227.139.114]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id C0B2F22D07 for ; Mon, 11 Jan 2021 23:20:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C0B2F22D07 Authentication-Results: mail.kernel.org; dmarc=pass (p=none dis=none) header.from=zx2c4.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=wireguard-bounces@lists.zx2c4.com Received: by lists.zx2c4.com (ZX2C4 Mail Server) with ESMTP id e9c75659; Mon, 11 Jan 2021 23:20:57 +0000 (UTC) Received: from mail.zx2c4.com (mail.zx2c4.com [167.71.246.149]) by lists.zx2c4.com (ZX2C4 Mail Server) with ESMTPS id 77de4c7e (TLSv1.3:AEAD-AES256-GCM-SHA384:256:NO) for ; Mon, 11 Jan 2021 23:20:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zx2c4.com; s=20210105; t=1610407252; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=YfknsT5Nff3vSIxpPDeH16Neo9fyfXmZ5rsJnqtpp4I=; b=A33LnmDZDpctAPGVvwyTK2KGyc0ULLA6JMO+Xhxzdho/1236/Jsqkt8pIZNwYw7HJh89xG Gu50m9OpqGg0n74D9mrUU4o7wdQehM1/l7Jl49OsEUx+9P1wXbXCeO35P008BzwS4+Kw3Q fLrQuZVuKs6iy4K5kFSgmnD4hmDQvTo= Received: by mail.zx2c4.com (ZX2C4 Mail Server) with ESMTPSA id 84d4d503 (TLSv1.3:AEAD-AES256-GCM-SHA384:256:NO) for ; Mon, 11 Jan 2021 23:20:52 +0000 (UTC) Received: by mail-yb1-f179.google.com with SMTP id f13so396551ybk.11 for ; Mon, 11 Jan 2021 15:20:52 -0800 (PST) X-Gm-Message-State: AOAM533QChRXfnc/Wig33TBGl+RljCuaJ+jh7A4/WXvGJAmH4ir9YzY4 I4KssN69OiLiQZ4QSYy3kOaMt7RlMDbva6xDugY= X-Google-Smtp-Source: ABdhPJy6FwZykhP6XVg/bq+mFdUwua2fkp8TXrD19qWJnibyt4WPX7ClP/QVJgcen3xCYXJajBezL9rQOWg4FykBsiU= X-Received: by 2002:a25:4d7:: with SMTP id 206mr3178181ybe.306.1610407251371; Mon, 11 Jan 2021 15:20:51 -0800 (PST) MIME-Version: 1.0 References: <78d6a7df-fa89-7d75-480b-aea3c52f72ee@gmail.com> In-Reply-To: <78d6a7df-fa89-7d75-480b-aea3c52f72ee@gmail.com> From: "Jason A. Donenfeld" Date: Tue, 12 Jan 2021 00:20:40 +0100 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: AMD RDRAND To: Germano Massullo Cc: WireGuard mailing list Content-Type: text/plain; charset="UTF-8" X-BeenThere: wireguard@lists.zx2c4.com X-Mailman-Version: 2.1.30rc1 Precedence: list List-Id: Development discussion of WireGuard List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: wireguard-bounces@lists.zx2c4.com Sender: "WireGuard" Hi Germano, On Mon, Jan 11, 2021 at 10:54 PM Germano Massullo wrote: > > I would like to inform Wireguard developers about the following. > it seems that this [1] old AMD RDRAND problem is still present: > RDRAND on AMD Ryzen 9 5900X is flakey - > https://github.com/systemd/systemd/issues/18184 > > I own 2x Ryzen 3600, feel free to write me in case you would like to run > some tests > > [1]: > https://arstechnica.com/gadgets/2019/10/how-a-months-old-amd-microcode-bug-destroyed-my-weekend/ I fixed this already, by removing the use of RDRAND from get_random_{u32,u64,int,long} entirely: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=69efea712f5b0489e67d07565aad5c94e09a3e52 This happened almost a year ago back in February, and was backported to the stable kernels too, which means you should have no issues finding a working kernel for your brand new Ryzen. Is this actually a problem you're experiencing or is your report mostly just speculation based on that systemd issue you linked to? Jason