Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965248AbbD0TLB (ORCPT ); Mon, 27 Apr 2015 15:11:01 -0400 Received: from mail.eperm.de ([89.247.134.16]:34544 "EHLO mail.eperm.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965122AbbD0TK4 (ORCPT ); Mon, 27 Apr 2015 15:10:56 -0400 From: Stephan Mueller To: Daniel Borkmann Cc: Hannes Frederic Sowa , mancha , tytso@mit.edu, linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org, herbert@gondor.apana.org.au, dborkman@redhat.com Subject: Re: [BUG/PATCH] kernel RNG and its secrets Date: Mon, 27 Apr 2015 21:10:14 +0200 Message-ID: <11353383.zL7vZDIZ69@tauon> User-Agent: KMail/4.14.6 (Linux/3.19.4-200.fc21.x86_64; KDE/4.14.6; x86_64; ; ) In-Reply-To: <2604864.n87lBBrmsR@tauon> References: <20150318095345.GA12923@zoho.com> <5527E22C.9080909@iogearbox.net> <2604864.n87lBBrmsR@tauon> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1391 Lines: 44 Am Freitag, 10. April 2015, 16:50:22 schrieb Stephan Mueller: Hi Stephan, >Am Freitag, 10. April 2015, 16:46:04 schrieb Daniel Borkmann: > >Hi Daniel, > >>On 04/10/2015 04:36 PM, Stephan Mueller wrote: >>> Am Freitag, 10. April 2015, 16:26:00 schrieb Hannes Frederic Sowa: >>... >> >>>> I suspected a problem in how volatile with non-present output args could >>>> be different, but this seems not to be the case. >>>> >>>> I would contact llvm/clang mailing list and ask. Maybe there is a >>>> problem? It seems kind of strange to me... >> >>+1 >> >>> Do you really think this is a compiler issue? >> >>If clang/LLVM advertises "GCC compatibility", then this would >>certainly be a different behavior. > >As you wish. I will contact the clang folks. As the proposed fix is not super >urgend, I think we can leave it until I got word from clang. I posted the issue on the clang mailing list on April 10 -- no word so far. I would interpret this as a sign that it is a no-issue for them. Thus, I propose we update our memzero_explicit implementation to use __asm__ __volatile__("" : "=r" (s) : "0" (s) : "memory"); Concerns? Ciao Stephan -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/