From patchwork Thu Aug 10 14:40:50 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Derrick Stolee X-Patchwork-Id: 13349538 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 2E16AC001E0 for ; Thu, 10 Aug 2023 14:40:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235061AbjHJOk4 (ORCPT ); Thu, 10 Aug 2023 10:40:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54888 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233148AbjHJOkz (ORCPT ); Thu, 10 Aug 2023 10:40:55 -0400 Received: from mail-wm1-x32b.google.com (mail-wm1-x32b.google.com [IPv6:2a00:1450:4864:20::32b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 49D8DE53 for ; Thu, 10 Aug 2023 07:40:54 -0700 (PDT) Received: by mail-wm1-x32b.google.com with SMTP id 5b1f17b1804b1-3fe4ad22eb0so8713745e9.3 for ; Thu, 10 Aug 2023 07:40:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1691678452; x=1692283252; h=cc:to:mime-version:content-transfer-encoding:fcc:subject:date:from :message-id:from:to:cc:subject:date:message-id:reply-to; bh=Xu7l+qsAOMwKzvgAzO8VkWEzsnC9H+1izWFXL/XgSzA=; b=XsGAOxwI7//GpE8pv+A1rXzfxTMn2W7GZiVbUBs2Msv73IVDfPu1JmLkcCBMT827DI SNPPpnFd81wRYnWuP9mUkgqte9IIb1zZ7uBZSCrhGUVRnXq7uiuTWHBsNmNDdI2Tr3L/ RhEz5sbkaoD5r8diw4GE9g0R1NrQQ3BfwgZRItoqHzkXeLIRKGUoSFEoQF8Gswvs3eBN iA0vRz9Mu6h0rEYwrJdO0GvlKIlM7GomQc+N/V/x0Jz1BYdUVECgokguW4qkVfuMmJBz w7a1S0+UXmZ+UX5VJFgOasx3mDpMR0IbDqSz7ML0PAkvZvVFXXgHOrV+PXBa2AZ1T4FJ 5Xiw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1691678452; x=1692283252; h=cc:to:mime-version:content-transfer-encoding:fcc:subject:date:from :message-id:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=Xu7l+qsAOMwKzvgAzO8VkWEzsnC9H+1izWFXL/XgSzA=; b=eghUIqB/wVFgmUZMqkwOpWoPCwOv8cUUKj2dDD3FP910oMhMhqIt9oPd0BFre8TNPt gGNctubL32/7PZtE36Kr8MfOfq68AtyWzzxoiWffzVqLtKWMi/tpSV2n2v67ahyj974v +hCjFOg4vGCs75kSx6n2N9saPrOJaPsshHck2Pgsh4zqDwW46Kr0ykccQLT0jlIJmRku Ha19Li3AS/Wvf0ORT/5OoI8MpVOa1Q5zFIYe95vrgqCkiUD5pQPHA3p8Q3r8rTpDDaKs JDiOUezltxdsSsTcYSzVzZ6OUpnSD7oKusCJ0mjaA/yus/RH5XHiUlov1Km+qIZwLBHW OQyw== X-Gm-Message-State: AOJu0YxDWKHPkFYAYOT2cKavmbsA+1jnbL0WaApcBtvDE/M+B9acjVJy AIS+OTq87242oH1OnMSUFm1Aucuyzbc= X-Google-Smtp-Source: AGHT+IHFqPKerhPIRx6uvX9rgKuJE+93l+ttKXKpPHe6cUAd+rol41M4/XaClyF/T5agMyIXoatTCw== X-Received: by 2002:a7b:c398:0:b0:3fe:173e:4a54 with SMTP id s24-20020a7bc398000000b003fe173e4a54mr2143039wmj.17.1691678452211; Thu, 10 Aug 2023 07:40:52 -0700 (PDT) Received: from [127.0.0.1] ([13.74.141.28]) by smtp.gmail.com with ESMTPSA id f1-20020a5d6641000000b00314367cf43asm2384995wrw.106.2023.08.10.07.40.51 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 10 Aug 2023 07:40:51 -0700 (PDT) Message-ID: Date: Thu, 10 Aug 2023 14:40:50 +0000 Subject: [PATCH] upload-pack: fix race condition in error messages Fcc: Sent MIME-Version: 1.0 To: git@vger.kernel.org Cc: gitster@pobox.com, Derrick Stolee , Derrick Stolee Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org From: Derrick Stolee From: Derrick Stolee Test t5516-fetch-push.sh has a test 'deny fetch unreachable SHA1, allowtipsha1inwant=true' that checks stderr for a specific error string from the remote. In some build environments the error sent over the remote connection gets mingled with the error from the die() statement. Since both signals are being output to the same file descriptor (but from parent and child processes), the output we are matching with grep gets split. To reduce the risk of this failure, follow this process instead: 1. Write an error message to stderr. 2. Write an error message across the connection. 3. exit(1). This reorders the events so the error is written entirely before the client receives a message from the remote, removing the race condition. Signed-off-by: Derrick Stolee --- upload-pack: fix race condition in error messages Here is another quick patch that we've been holding in the microsoft/git fork for years because it helped prevent some test flakiness, especially in our more involved functional test environment. Thanks, -Stolee Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1572%2Fderrickstolee%2Fupload-pack-race-v1 Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1572/derrickstolee/upload-pack-race-v1 Pull-Request: https://github.com/gitgitgadget/git/pull/1572 upload-pack.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) base-commit: a82fb66fed250e16d3010c75404503bea3f0ab61 diff --git a/upload-pack.c b/upload-pack.c index 94751477ab2..7b25129f0f6 100644 --- a/upload-pack.c +++ b/upload-pack.c @@ -801,11 +801,12 @@ error: for (i = 0; i < data->want_obj.nr; i++) { struct object *o = data->want_obj.objects[i].item; if (!is_our_ref(o, data->allow_uor)) { + error("git upload-pack: not our ref %s", + oid_to_hex(&o->oid)); packet_writer_error(&data->writer, "upload-pack: not our ref %s", oid_to_hex(&o->oid)); - die("git upload-pack: not our ref %s", - oid_to_hex(&o->oid)); + exit(1); } } }