From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ob0-f173.google.com ([209.85.214.173]:40661 "EHLO mail-ob0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753597AbaIKVnw (ORCPT ); Thu, 11 Sep 2014 17:43:52 -0400 Received: by mail-ob0-f173.google.com with SMTP id m8so685931obr.18 for ; Thu, 11 Sep 2014 14:43:51 -0700 (PDT) Message-ID: <54121651.50004@converseincode.com> Date: Thu, 11 Sep 2014 16:38:25 -0500 From: Behan Webster MIME-Version: 1.0 To: Chris Mason , jbacik@fb.com CC: linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org, =?UTF-8?B?Vmluw61jaXVzIFRpbnRp?= , =?UTF-8?B?SmFuLVNpbW9uIE3DtmxsZXI=?= , Mark Charlebois Subject: Re: [PATCH v2] btrfs: LLVMLinux: Remove VLAIS References: <1409957901-28962-1-git-send-email-behanw@converseincode.com> <5411B304.4000203@fb.com> In-Reply-To: <5411B304.4000203@fb.com> Content-Type: text/plain; charset=utf-8; format=flowed Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 09/11/14 09:34, Chris Mason wrote: > > On 09/05/2014 06:58 PM, behanw@converseincode.com wrote: >> From: Vinícius Tinti >> >> Replaced the use of a Variable Length Array In Struct (VLAIS) with a C99 >> compliant equivalent. This is the original VLAIS struct. >> >> struct { >> struct shash_desc shash; >> char ctx[crypto_shash_descsize(tfm)]; >> } desc; >> >> This patch instead allocates the appropriate amount of memory using an char >> array. >> >> The new code can be compiled with both gcc and clang. >> >> struct shash_desc contains a flexible array member member ctx declared with >> CRYPTO_MINALIGN_ATTR, so sizeof(struct shash_desc) aligns the beginning >> of the array declared after struct shash_desc with long long. >> >> No trailing padding is required because it is not a struct type that can >> be used in an array. >> >> The CRYPTO_MINALIGN_ATTR is required so that desc is aligned with long long >> as would be the case for a struct containing a member with >> CRYPTO_MINALIGN_ATTR. > We copied this from one of the other crypto api users, and I'm sure > cooking up all these patches was not a great way to your afternoon. > > But, can I talk you into making a helper macro of some kind for this and > putting it into the crypto api headers? Honestly this setup seems > really error prone. You're not the only person to ask for this. I've got one already coded up based on suggestions from tglx. I've regenerated all the patches. I will resubmit soon. Will fix. Behan -- Behan Webster behanw@converseincode.com