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=-6.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,URIBL_BLOCKED autolearn=ham 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 06AE9C54E4B for ; Tue, 12 May 2020 08:03:11 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id C6A352075E for ; Tue, 12 May 2020 08:03:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="co7FP3Vg" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C6A352075E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=oracle.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:37910 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jYPsc-000757-0Y for qemu-devel@archiver.kernel.org; Tue, 12 May 2020 04:03:10 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:59988) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jYPrW-00067H-07 for qemu-devel@nongnu.org; Tue, 12 May 2020 04:02:02 -0400 Received: from aserp2120.oracle.com ([141.146.126.78]:39136) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jYPrU-0004ot-UJ for qemu-devel@nongnu.org; Tue, 12 May 2020 04:02:01 -0400 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 04C7l1wQ148252; Tue, 12 May 2020 08:01:59 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : in-reply-to : references : date : message-id : mime-version : content-type; s=corp-2020-01-29; bh=5IMmnEnffuj4VRXJfytQyjtbOaAo9hK3PVrs4zKPBC4=; b=co7FP3Vgo0CVkI2uYPE4Pli4rHWeUu435iI7tDqzg7ksVxT2vPNdIGasxQyteLkmwD97 P5/1V0XO3ZFhdR7VbtdQsA/VxrbKiM9Ib7n51aDD+PZRQw7T74KQT7F0EGq94ScoCBnP lRIK4MkasfnfYirVgz5jaBzXnVVxs605hjVwdIV4Y8eDLQeFbfEzdlbZZuC2zfgdTFeS WGdw3lTQuDITKYOOzVEJrrSZVlY7eN0B+sKFfUZNrxpMhzb8uyNMUBkth+3lGvMMm3ie lssmeN/7UtK0A4Z79JoDhdPv1oSrJHlQJ2kaWxEfAZ2V4S0nuKqRqS15bswmdorITCW+ Tg== Received: from userp3020.oracle.com (userp3020.oracle.com [156.151.31.79]) by aserp2120.oracle.com with ESMTP id 30x3gshdea-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Tue, 12 May 2020 08:01:59 +0000 Received: from pps.filterd (userp3020.oracle.com [127.0.0.1]) by userp3020.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 04C7gJFx076474; Tue, 12 May 2020 08:01:58 GMT Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by userp3020.oracle.com with ESMTP id 30x69spngc-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 12 May 2020 08:01:58 +0000 Received: from abhmp0020.oracle.com (abhmp0020.oracle.com [141.146.116.26]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id 04C81vIv002096; Tue, 12 May 2020 08:01:57 GMT Received: from starbug-mbp.localdomain (/79.97.215.145) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 12 May 2020 01:01:56 -0700 Received: by starbug-mbp.localdomain (Postfix, from userid 501) id 3A2576920C67; Tue, 12 May 2020 09:01:54 +0100 (IST) From: Darren Kenny To: Alexander Bulekov , qemu-devel@nongnu.org Subject: Re: [PATCH 3/4] fuzz: add mangled object name to linker script In-Reply-To: <20200512030133.29896-4-alxndr@bu.edu> References: <20200512030133.29896-1-alxndr@bu.edu> <20200512030133.29896-4-alxndr@bu.edu> Date: Tue, 12 May 2020 09:01:54 +0100 Message-ID: MIME-Version: 1.0 Content-Type: text/plain X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9618 signatures=668687 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 bulkscore=0 malwarescore=0 adultscore=0 spamscore=0 suspectscore=1 mlxscore=0 mlxlogscore=999 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2005120067 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9618 signatures=668687 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 mlxlogscore=999 malwarescore=0 adultscore=0 mlxscore=0 priorityscore=1501 lowpriorityscore=0 impostorscore=0 clxscore=1015 bulkscore=0 phishscore=0 suspectscore=1 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2005120067 Received-SPF: pass client-ip=141.146.126.78; envelope-from=darren.kenny@oracle.com; helo=aserp2120.oracle.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/05/12 03:59:36 X-ACL-Warn: Detected OS = Linux 3.1-3.10 [fuzzy] X-Spam_score_int: -43 X-Spam_score: -4.4 X-Spam_bar: ---- X-Spam_report: (-4.4 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001, UNPARSEABLE_RELAY=0.001, URIBL_BLOCKED=0.001 autolearn=_AUTOLEARN X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Laurent Vivier , Thomas Huth , Alexander Bulekov , bsd@redhat.com, stefanha@redhat.com, Paolo Bonzini Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Monday, 2020-05-11 at 23:01:32 -04, Alexander Bulekov wrote: > Previously, we relied on "FuzzerTracePC*(.bss*)" to place libfuzzer's > fuzzer::TPC object into our contiguous shared-memory region. This does > not work for some libfuzzer builds, so this addition identifies the > region by its mangled name: *(.bss._ZN6fuzzer3TPCE); > > Signed-off-by: Alexander Bulekov FWIW, since I'm not really familiar with the syntax, but I understand what the intent is: Reviewed-by: Darren Kenny > --- > tests/qtest/fuzz/fork_fuzz.ld | 5 +++++ > 1 file changed, 5 insertions(+) > > This isn't ideal, but I looked at the libfuzzer builds packaged for > debian, for versions 6, 7, 8, 9, 10 and 11 and this (mangled) object > name appears consistently in the symbol tables. > > diff --git a/tests/qtest/fuzz/fork_fuzz.ld b/tests/qtest/fuzz/fork_fuzz.ld > index e086bba873..bfb667ed06 100644 > --- a/tests/qtest/fuzz/fork_fuzz.ld > +++ b/tests/qtest/fuzz/fork_fuzz.ld > @@ -28,6 +28,11 @@ SECTIONS > > /* Internal Libfuzzer TracePC object which contains the ValueProfileMap */ > FuzzerTracePC*(.bss*); > + /* > + * In case the above line fails, explicitly specify the (mangled) name of > + * the object we care about > + */ > + *(.bss._ZN6fuzzer3TPCE); > } > .data.fuzz_end : ALIGN(4K) > { > -- > 2.26.2