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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EA35BC4332F for ; Tue, 18 Oct 2022 14:12:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230020AbiJROMI (ORCPT ); Tue, 18 Oct 2022 10:12:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52792 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231381AbiJROLg (ORCPT ); Tue, 18 Oct 2022 10:11:36 -0400 Received: from fanzine2.igalia.com (fanzine.igalia.com [178.60.130.6]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 38AE97D78E; Tue, 18 Oct 2022 07:11:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Content-Transfer-Encoding:Content-Type:In-Reply-To:From: References:Cc:To:Subject:MIME-Version:Date:Message-ID:Sender:Reply-To: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=j86gyI86b1ZCBfCx7LMeZ2ebnxH6k+wMdKl4XDSS43U=; b=JGiKivI9rOFU0nX92BHk01p0ZO tnzVZKP+YZFd2bNPGOkKSmXr5oH/8XIs+/y3U5M3zKAD2nG0jWezbwcZFmqoUs/Pli3e5Sqqp5QFN SJYsWCca1jAuUGuupyWk2e8eUXmmDUzbalU8W/ym/udYJ8+QzSWepguZYvMk1bRgHCFUeZ3wOOR+6 XWCqDlPbRod/fMF46OxnbAH+zkBCg0bTqUjz3fhsDEDNKNNXJ0DLWtRHOn4GpENFIulckmDNUy70V jI4N5hLkUSZMY6cG6VNsCjeq0W20dSNNvC/E1DqVvhPG0Mp2kCf5I28COq33/QUDwYxxB1URbydT/ /73I0g7Q==; Received: from [179.113.159.85] (helo=[192.168.1.60]) by fanzine2.igalia.com with esmtpsa (Cipher TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_128_GCM:128) (Exim) id 1oknJ6-0013bB-B1; Tue, 18 Oct 2022 16:11:00 +0200 Message-ID: <8d40dad4-4b20-2ec3-a8e1-706dd415f0d2@igalia.com> Date: Tue, 18 Oct 2022 11:10:53 -0300 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.3.2 Subject: Re: [PATCH 0/5] pstore: Use zstd directly by default for compression To: Ard Biesheuvel , Kees Cook Cc: Tony Luck , Nick Terrell , linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org References: <20221018020519.never.337-kees@kernel.org> Content-Language: en-US From: "Guilherme G. Piccoli" In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 18/10/2022 05:20, Ard Biesheuvel wrote: > [...] > So again, I suggest to simply drop this non-feature, and standardize > on either zlib or zstd using the library interface exclusively. If > someone present a compelling use case, we can always consider adding > it back in some form. > > As for the choice of algorithm, given the equal performance using the > default compression level, and the difference in code size, I don't > see why zstd should be preferred here. If anything, it only increases > the likelihood of hitting another error if we are panicking due to > some memory corruption issue. I think it's a good argument - would zlib be simpler in code than zstd? I've checked the zstd patch from Kees - not complex per se, but would be great if we could have a simple mechanism, without the need of the ifdef there for example... Cheers, Guilherme