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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3DE3CC433F5 for ; Tue, 16 Nov 2021 22:13:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 22B8263222 for ; Tue, 16 Nov 2021 22:13:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231389AbhKPWQB (ORCPT ); Tue, 16 Nov 2021 17:16:01 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33840 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231974AbhKPWQA (ORCPT ); Tue, 16 Nov 2021 17:16:00 -0500 Received: from mail-oi1-x22d.google.com (mail-oi1-x22d.google.com [IPv6:2607:f8b0:4864:20::22d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6558EC061570 for ; Tue, 16 Nov 2021 14:13:03 -0800 (PST) Received: by mail-oi1-x22d.google.com with SMTP id n66so1668187oia.9 for ; Tue, 16 Nov 2021 14:13:03 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=message-id:date:mime-version:user-agent:subject:content-language:to :cc:references:from:in-reply-to:content-transfer-encoding; bh=p/HdqS5kDuJMFXdNImf7h/iqKkUm/UzJZ6dBcWIsy5M=; b=Ndk2tFRXgz5JMlYDKXjhpxhy2XRrm521I9yPLvlBi0v5lIjxTfcZXdM55/ES2WSfOB l1frxDpV96sbtHzJDjGbvtz7MPszj9tnIYXUnttn7bqZxSpsSKubnYGulr34RR1BOlYU 8sNbatjlOWVwgUvqPfdf8821EOajMSfkwzB/ETjTWwjIIUezxeYD/yQn6xRNEFG5ouIZ CJ7+wPVwr4UG+/fUc+Si/9ZccMSYvlTdFGtrBwKoXs3JnNd2Rxic4SFAJ3K0KYPJ3pw3 t0KMNVJ6fiC1pcvmA4XDQnkeTe1WWdIVWIK5Xt5Top/f3Hqm+9zMGN0xBuV7vZ2WYD6M 9kNA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=p/HdqS5kDuJMFXdNImf7h/iqKkUm/UzJZ6dBcWIsy5M=; b=VgQzTXNO/iw/KJeXRm2kTlhP+hc7Mi7rRRkw433Gqx69Xx9+E2HHAlL3tbnncG5OsW JL/JbO6cD0TMHDFiA5iShfSVVcGYt9C5sDwbsawBgnrQC4VufbtmyRr0jZf+mmqBs19H 00N1hfCT5Sdnlx1t1IEjDgdT5A9/1YIHTh3IdbO+i60OFH5qDUR4ETHYwiic2Py/MVfb 2aECI1BsdwNv8Zo1cgIXclziowvESqOQTqLsz6M3+OTt3WNBX20x98kjqyT8PxSBRZGG RwIT6K/w1/0I8JQt9vsOG3G1ENswgRtxMdNxxNpy7Q9DERTDnzblOGpvrVUN1BPFLyvQ 3mbw== X-Gm-Message-State: AOAM531jiXxyFvOzhYUkEU0X8NWI/izHTbyGWgmWOu/uO2EGroobp+vo ZN3Oj2YjR8kueipzzi+8hHY= X-Google-Smtp-Source: ABdhPJzuipRGNKEKlAnssvAPLv9GEkWDc1QlJ+NufNektC0WLZ4+aBntCHSyMvfg6DU9bX4RJ6Zv9g== X-Received: by 2002:a05:6808:1185:: with SMTP id j5mr56084669oil.16.1637100782537; Tue, 16 Nov 2021 14:13:02 -0800 (PST) Received: from ?IPV6:2600:1700:e72:80a0:1061:bd63:e16a:f842? ([2600:1700:e72:80a0:1061:bd63:e16a:f842]) by smtp.gmail.com with ESMTPSA id n22sm3298866oop.29.2021.11.16.14.13.01 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 16 Nov 2021 14:13:01 -0800 (PST) Message-ID: Date: Tue, 16 Nov 2021 17:12:59 -0500 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.3.1 Subject: Re: [PATCH] t5319: corrupt more bytes of the midx checksum Content-Language: en-US To: Jeff King , Taylor Blau Cc: =?UTF-8?Q?SZEDER_G=c3=a1bor?= , git@vger.kernel.org, dstolee@microsoft.com References: <94e9de44e3b52513c5ab48aecd74f809dc34cbe3.1624473543.git.me@ttaylorr.com> <20211110231132.GB5811@szeder.dev> From: Derrick Stolee In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org On 11/16/2021 4:38 PM, Jeff King wrote: > So very occasionally we can end up with a real 0xff byte, and the test > fails. The most robust fix would be to read out the final byte and then > change it to something else (e.g., adding 1 mod 256). But that's awkward > to do in shell. Let's just blindly corrupt 10 bytes instead of 1, which > reduces our chances of an accidental noop to 1 in 2^80. > > Reported-by: SZEDER Gábor > Signed-off-by: Jeff King > --- > t/t5319-multi-pack-index.sh | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/t/t5319-multi-pack-index.sh b/t/t5319-multi-pack-index.sh > index 3f69e43178..a612e44547 100755 > --- a/t/t5319-multi-pack-index.sh > +++ b/t/t5319-multi-pack-index.sh > @@ -482,8 +482,10 @@ test_expect_success 'corrupt MIDX is not reused' ' > ' > > test_expect_success 'verify incorrect checksum' ' > - pos=$(($(wc -c <$objdir/pack/multi-pack-index) - 1)) && > - corrupt_midx_and_verify $pos "\377" $objdir "incorrect checksum" > + pos=$(($(wc -c <$objdir/pack/multi-pack-index) - 10)) && > + corrupt_midx_and_verify $pos \ > + "\377\377\377\377\377\377\377\377\377\377" \ > + $objdir "incorrect checksum" > ' Thanks for taking the time to make this a patch. This approach looks good to me. Thanks, -Stolee