From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AG47ELuPS2zQBESACElHcPbldxAwq52TeaFvZMtgFlTLqwxF69nLPtugQFAYEcVtfRrBI2LSinu7 ARC-Seal: i=1; a=rsa-sha256; t=1521050100; cv=none; d=google.com; s=arc-20160816; b=sT378CTlNUpWRyb0RAe/BpFuX9JIxiTKY/hoJNB5lJelnPh7c3kvt0KOtl3TFvQsuJ bkZGX+s/bIfyC9IbNHCvBoCyo7xe+BStJNuXdkqZiKQVwe3X2ECqfA3/IAYPGE16sN70 Tr6w4IyWmtE+U+FUoUW+4qzOFXBZ1E93wRfVHg7wM4dk+mF+CnF8T6ERu27oKZrQyvo/ onbKGK+L8/FU+n9Yx5o9pxClQATzrUcisRXhe7aH0K8SSf0hSsfghR+y5kMu3TiBwp57 pSSFQ+3PuuBzmwo0yewHfqjzPPNCNdvdmIxS0cUxv9/7eEDybBKt+li3t4lnYTJrkcjR fnSA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=user-agent:in-reply-to:content-disposition:mime-version:references :mail-followup-to:message-id:subject:cc:to:from:date:delivered-to :delivered-to:list-id:list-subscribe:list-unsubscribe:list-help :list-post:precedence:mailing-list:arc-authentication-results; bh=fBb/kMZ0ZtzmvWGUuFFUcCh5xHovYnYn9j7YI1rbQpE=; b=WeWRChvE1dhU5oGvWyvO3jgaNVSzh3+dHfoHaDSplJVj8mchFMoQe9PuppKiFMOfgg +CBaGK0c8ogo0N2XlqdQ3n/PeBaVF5kaMcNKxFdXnZuGBT3Nji1vuG86nx1X4sgJcHvK J1lQC9o+Ec4Dni3idF5nevAeCBtzb0T+QsCwvmxZdbwNb+sGJYfknEOnv+sLp+4abx4q XyLW2jD8gwYHzdnNW/+G4Ywe6EXbvkXNNzSknshF8kW+n3kh6Mh1SCKYKFioHXEho2/Q w0CEfmaMU+DTL/2K9W1/vhoRVuxbZcQCFxCzeha7IdTLlgV0wusL1FWfUQ/PsN6DDYae 0G5Q== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of kernel-hardening-return-12613-gregkh=linuxfoundation.org@lists.openwall.com designates 195.42.179.200 as permitted sender) smtp.mailfrom=kernel-hardening-return-12613-gregkh=linuxfoundation.org@lists.openwall.com Authentication-Results: mx.google.com; spf=pass (google.com: domain of kernel-hardening-return-12613-gregkh=linuxfoundation.org@lists.openwall.com designates 195.42.179.200 as permitted sender) smtp.mailfrom=kernel-hardening-return-12613-gregkh=linuxfoundation.org@lists.openwall.com Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm List-Post: List-Help: List-Unsubscribe: List-Subscribe: Date: Wed, 14 Mar 2018 16:42:48 +0100 From: David Sterba To: Salvatore Mesoraca Cc: linux-kernel@vger.kernel.org, kernel-hardening@lists.openwall.com, linux-btrfs@vger.kernel.org, Chris Mason , David Sterba , Josef Bacik , Kees Cook Subject: Re: [PATCH] Btrfs: drop a VLA in btrfs_check_super_csum() Message-ID: <20180314154248.GL32007@twin.jikos.cz> Mail-Followup-To: dsterba@suse.cz, Salvatore Mesoraca , linux-kernel@vger.kernel.org, kernel-hardening@lists.openwall.com, linux-btrfs@vger.kernel.org, Chris Mason , David Sterba , Josef Bacik , Kees Cook References: <1520970622-19535-1-git-send-email-s.mesoraca16@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1520970622-19535-1-git-send-email-s.mesoraca16@gmail.com> User-Agent: Mutt/1.5.23.1 (2014-03-12) X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1594853328339341486?= X-GMAIL-MSGID: =?utf-8?q?1594936630069700772?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On Tue, Mar 13, 2018 at 08:50:22PM +0100, Salvatore Mesoraca wrote: > Avoid a VLA[1] by using a real constant expression instead of a variable. > The compiler should be able to optimize the original code and avoid using > an actual VLA. Anyway this change is useful because it will avoid a false > positive with -Wvla, it might also help the compiler generating better > code. > > [1] https://lkml.org/lkml/2018/3/7/621 > > Signed-off-by: Salvatore Mesoraca We already have a patch for that from a few days ago, but thanks anyway. https://patchwork.kernel.org/patch/10277901/