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=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_NEOMUTT 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 EC73CECDFB0 for ; Fri, 13 Jul 2018 05:21:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5B036208E2 for ; Fri, 13 Jul 2018 05:21:08 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5B036208E2 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=gondor.apana.org.au Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726591AbeGMFeC (ORCPT ); Fri, 13 Jul 2018 01:34:02 -0400 Received: from orcrist.hmeau.com ([104.223.48.154]:45148 "EHLO deadmen.hmeau.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725912AbeGMFeC (ORCPT ); Fri, 13 Jul 2018 01:34:02 -0400 Received: from gondobar.mordor.me.apana.org.au ([192.168.128.4] helo=gondobar) by deadmen.hmeau.com with esmtps (Exim 4.89 #2 (Debian)) id 1fdqVS-00038S-Ba; Fri, 13 Jul 2018 13:20:38 +0800 Received: from herbert by gondobar with local (Exim 4.89) (envelope-from ) id 1fdqVJ-0006nx-A0; Fri, 13 Jul 2018 13:20:29 +0800 Date: Fri, 13 Jul 2018 13:20:29 +0800 From: Herbert Xu To: Kees Cook Cc: Arnd Bergmann , "Gustavo A. R. Silva" , Eric Biggers , Alasdair Kergon , Giovanni Cabiddu , Lars Persson , Mike Snitzer , Rabin Vincent , Tim Chen , "David S. Miller" , Masahiro Yamada , "open list:HARDWARE RANDOM NUMBER GENERATOR CORE" , qat-linux@intel.com, dm-devel@redhat.com, Linux Kernel Mailing List Subject: Re: [PATCH v4 11/14] treewide: Prepare to remove VLA usage for AHASH_REQUEST_ON_STACK Message-ID: <20180713052029.cfo24bsr5swtbdja@gondor.apana.org.au> References: <20180711203619.1020-1-keescook@chromium.org> <20180711203619.1020-12-keescook@chromium.org> <20180713004038.lwibdesz7ohhoind@gondor.apana.org.au> <20180713034406.zwu2pkp3f2onybxs@gondor.apana.org.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 12, 2018 at 10:17:29PM -0700, Kees Cook wrote: > > Then why does the instrumented tcrypt output show the huge size? Is > tcrypt doing something incorrectly? tcrypt doesn't even use AHASH_REQUEST_ON_STACK so I don't understand your point. > What is the correct value to use for AHASH_REQUEST_ON_STACK? As I said to arrive at a fixed value you should examine all sync ahash algorithms (e.g., all shash ones plus ahash ones marked as sync if there are any). Cheers, -- Email: Herbert Xu Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt