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 X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9EFE3C433E0 for ; Thu, 4 Mar 2021 15:29:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 65EA264F21 for ; Thu, 4 Mar 2021 15:29:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234630AbhCDP2w (ORCPT ); Thu, 4 Mar 2021 10:28:52 -0500 Received: from mx.kolabnow.com ([95.128.36.41]:42142 "EHLO mx.kolabnow.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233616AbhCDP2U (ORCPT ); Thu, 4 Mar 2021 10:28:20 -0500 Received: from localhost (unknown [127.0.0.1]) by ext-mx-out002.mykolab.com (Postfix) with ESMTP id CD81BBCD; Thu, 4 Mar 2021 16:26:27 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kolabnow.com; h= content-transfer-encoding:content-language:content-type :content-type:in-reply-to:mime-version:date:date:message-id:from :from:references:subject:subject:received:received:received; s= dkim20160331; t=1614871587; x=1616685988; bh=JQZJoflvvfq8p8tHV8w XAEZ9rRIIVrCRIMUuZCKTdhc=; b=QLLwB1b5Arr1iBGVUcg8s1AxejKLUJD66ff 9YDKPxgCxYD1aJxqA4evQGKkN5TtmE3UP9E0gNRLdUxd1riDeYPErDw6mZvkH+sR zYk5nJ4ZnRybsA71eXwi+HKp/ZfvFLTTBUUE/LbAJe/wWYVfF9vTY1L7Ks7w5BJK pnIk8Ld3LmYZWVy51h05m3HsjeHXTIziRBj/mN1/sQYhL0EnRCGi+hYDtSkYKbg6 B4HwZ17hqxdMpOpmfOtRBLzGGqTGsiJAfBM2HnhvhDCKaRkhWPz/AbCg8rGXe9P5 drcQoihSHFraQXtFis1d0PEmLPbFU850J5MLyCkv6X8Hg4xae3vOhK+DpxYb+zv2 vPXAk9brnIoPk99bRboFuEOHtAVuQXWkxHiGNTno45rJwGmln6ZcT+k6VxtskXRi rRNQCMM1uskA4tJ6D/VMTkNj3QgZejsmtV1yQEstoWAhzkFDxAwafkJH3xiwbRom plo+blCCfeQrM0/tT/G57SmmoSmPXv8oa2bKmxoFXzSSFprmoHjEkCgFUcPEBdBg gxJoQXxxIgo27WKJhXJ0efwy06qi6xPD22tXTXfm+4hO2EEhMyv/rY7ro8AlFRqK AWW6iUMWhQYoQH/s6tP4WoGhySEDuzROioFOHlf20pQp8T3fWN97kb+yutTDPJJb bv9htGaM= X-Virus-Scanned: amavisd-new at mykolab.com Received: from mx.kolabnow.com ([127.0.0.1]) by localhost (ext-mx-out002.mykolab.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 4ye-iO-PnBC3; Thu, 4 Mar 2021 16:26:27 +0100 (CET) Received: from int-mx003.mykolab.com (unknown [10.9.13.3]) by ext-mx-out002.mykolab.com (Postfix) with ESMTPS id F1763BCC; Thu, 4 Mar 2021 16:26:26 +0100 (CET) Received: from ext-subm002.mykolab.com (unknown [10.9.6.2]) by int-mx003.mykolab.com (Postfix) with ESMTPS id 87186310C; Thu, 4 Mar 2021 16:26:23 +0100 (CET) Subject: Re: [PATCH] Update 'make fuzz-all' docs to reflect modern clang To: Josh Steadmon , Andrzej Hunt via GitGitGadget , git@vger.kernel.org, Andrzej Hunt References: From: Andrzej Hunt Message-ID: <094d75bf-707a-5b0d-fead-5c9ad08e0a18@ahunt.org> Date: Thu, 4 Mar 2021 16:26:21 +0100 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org On 01/03/2021 23:39, Josh Steadmon wrote: > Thanks for taking a look at this! This looked correct to me, but when I > tried to run the fuzzers I got an error about > "-fsanitize-coverage=trace-pc-guard" not being supported any longer. Oops, I realised I was accidentally using clang 7 (instead of 11) locally. I can reproduce the same error with my copy of clang-11. Thanks for catching this! > Looking at the LLVM 11.0.0 docs [1], I see that it recommends using > "-fsanitize=fuzzer-no-link" instead (the "-no-link" is because we're > also building executables that have their own main()). > > So we'd also want to change CFLAGS to > "-fsanitize=fuzzer-no-link,address". I will fix this too! I suspect that when I built without fuzzer-no-link, the fuzzer binaries included libFuzzer, but were missing whatever fuzzing-related instrumentation clang should have added. (Fortunately oss-fuzz seems to be adding this to the CFLAGS automatically [1].) [1] https://oss-fuzz-build-logs.storage.googleapis.com/log-74f40f33-f384-475b-b141-0e44afb272f5.txt