From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 8EE692EB861; Sun, 19 Oct 2025 15:03:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760886215; cv=none; b=dZhcnwDOnShEoqgn+jToU2j5cON4KtqEsduFQuE2mriNzgCnnl0Dw/FqTmFqwfPXSq8g10Bskq9/duK+XVFjCn+tfgD+i3C2vEZAjQwVIFXycwHXNnxdZktUSHxXmiKLiX4HwDem/kObHfgN2HuufwnWJlQcF8z8/eAPHFVWo7M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760886215; c=relaxed/simple; bh=CvUdrAhJKrAFPUNmEfVgBrHXrqkfuXKEui6HESMt9gc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=D22CDUN7uQF5ZJ7HcRBj8rAfQIMR0EwngYgdLaeCO/fvdmK3xrGwKNT81c4i9F3fTlRnmHVfBYMLmJBR1/9/gu1V1n2DB5sry+wM8KbP+YHL/aiQ6GQyg8NBdLFLMOmSFcu61hZHbjzja72ZgCWy3R8lwohytqet1SQcq77RIMQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b=YCb3pyJw; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b="YCb3pyJw" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8C015C4CEF1; Sun, 19 Oct 2025 15:03:33 +0000 (UTC) Authentication-Results: smtp.kernel.org; dkim=pass (1024-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b="YCb3pyJw" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zx2c4.com; s=20210105; t=1760886208; 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=Jir822fJVXvlFL1pNOJ9mf5/pCTgHfz0MI2r7sxik9s=; b=YCb3pyJw9PTsualD3YKs1UTSHYeVss1rYlK6EUPUxqfqb2QS9dOJHNCOLB64NY3Bjd+zhp ncMsXdgBHYZuIY0hjF7i61ytYmSlKahfU9p0Wy4sfF6C3IMclpYyVqrPiR0FQxChK0G+fJ BWLWbKuckw00Wc5YxzAAyc2ThTnVY6A= Received: by mail.zx2c4.com (ZX2C4 Mail Server) with ESMTPSA id bc093c64 (TLSv1.3:TLS_AES_256_GCM_SHA384:256:NO); Sun, 19 Oct 2025 15:03:28 +0000 (UTC) Date: Sun, 19 Oct 2025 17:03:25 +0200 From: "Jason A. Donenfeld" To: Borislav Petkov Cc: Gregory Price , x86@kernel.org, linux-kernel@vger.kernel.org, tglx@linutronix.de, mingo@redhat.com, dave.hansen@linux.intel.com, hpa@zytor.com, peterz@infradead.org, mario.limonciello@amd.com, riel@surriel.com, yazen.ghannam@amd.com, me@mixaill.net, kai.huang@intel.com, sandipan.das@amd.com, darwi@linutronix.de, stable@vger.kernel.org Subject: Re: [PATCH v2] x86/amd: Disable RDSEED on AMD Zen5 because of an error. Message-ID: References: <20251018024010.4112396-1-gourry@gourry.net> <20251018100314.GAaPNl4ngomUnreTbZ@fat_crate.local> <20251019150027.GAaPT9Cz6NjB9S2d2a@fat_crate.local> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20251019150027.GAaPT9Cz6NjB9S2d2a@fat_crate.local> On Sun, Oct 19, 2025 at 05:00:27PM +0200, Borislav Petkov wrote: > On Sun, Oct 19, 2025 at 04:46:06PM +0200, Jason A. Donenfeld wrote: > > While your team is checking into this, I'd be most interested to know > > one way or the other whether this affects RDRAND too. > > No it doesn't, AFAIK. The only one affected is the 32-bit or 16-bit dest > operand version of RDSEED. Again, AFAIK. Oh good. So on 64-bit kernels, the impact to random.c is zilch. Jason