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=-18.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,MSGID_FROM_MTA_HEADER, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 3C586C4338F for ; Mon, 26 Jul 2021 04:56:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 069D1604AC for ; Mon, 26 Jul 2021 04:56:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229524AbhGZEQM (ORCPT ); Mon, 26 Jul 2021 00:16:12 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:30986 "EHLO mx0b-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229468AbhGZEQM (ORCPT ); Mon, 26 Jul 2021 00:16:12 -0400 Received: from pps.filterd (m0109331.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 16Q4tocm001972; Sun, 25 Jul 2021 21:56:28 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=subject : to : cc : references : from : message-id : date : in-reply-to : content-type : content-transfer-encoding : mime-version; s=facebook; bh=QAGCEGpixwQsax5NIsIrTwly6TzXvLUH7XO+YxhXm6w=; b=d06HMD0sgMF6VDhB1HAddWcqjAuEtAfYwnO/OVLKG60PbBJRP9AFncF09prOkRKze0DZ 1xiiNcm9lmDTfPWmuoTZfj5/fHh0gN+6CTPoatnSAd2ITDgoPeGbP/3IYvjtH1lCcmuE NimCMgGTkSMGr+PWluc/D+4x8Je+NIMLfjE= Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com with ESMTP id 3a0gpw7dam-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT); Sun, 25 Jul 2021 21:56:28 -0700 Received: from NAM12-MW2-obe.outbound.protection.outlook.com (100.104.98.9) by o365-in.thefacebook.com (100.104.94.197) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Sun, 25 Jul 2021 21:56:26 -0700 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=jXfSQ+YIW4v0nQa73lDXoGt6rS6IL0nSF3VFlbCWZYTxt1Bbup0RPGpXDYPJ2OvoDDKYg38dRCUbFdVO+hFC5+IfobQQbcbU7Yoa8lkcyWqphZaC6WeOrxjYLaxx4mgpcTLbU5oLOxTx6I6WsNZPkTA8aJX96HwWR/QI0iW7JNrHmRIUKQlqhF1+M5YVt4ADdQ+9pzCLD0KxsRt1bJgsjWcyvHgBxrCj/NgpCQ1mIYDmbvoWzNmEfKhN8jLlXsKwsu3X6/GnVmJ9bdZdiv6hJl7jXm3enPi5ZhNzlXWNRNHy/T2YPP7UdB0O98d/901z2LaeKvGro3p9CghfzaGxbA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=QAGCEGpixwQsax5NIsIrTwly6TzXvLUH7XO+YxhXm6w=; b=GqPK9ojuzCrAYsSkwcXrewbkyX50QaPokdUwyPwpK/WlrBgxMDbXNrZySx90bctl3QFeb5Xl3lRJsdS0Z0urbO7PO4mqDoQQj/vmNbHJTk+gUEQlGq0+jtzR2HbNccXnfEgACnZPcO2unTgPe5/q+B1wrDTv0sjoyGiMUvTYJY9q3qVJIFcfmz9TS6UKSviUinM59KFxh+Hhy418gOryYL7pb00A1rmxrBiERkdjPbSG1XfRKWHTnNBvdpcnYpq1YNu50aX2PwUqxF2kL5RtbbzIqcvnoV6rnwUM4LHw0X1E4997PF79LgCNsnGgWgxUAiTLXoXYg9bGREPDlfHMYA== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=fb.com; dmarc=pass action=none header.from=fb.com; dkim=pass header.d=fb.com; arc=none Authentication-Results: gmail.com; dkim=none (message not signed) header.d=none;gmail.com; dmarc=none action=none header.from=fb.com; Received: from SN6PR1501MB2064.namprd15.prod.outlook.com (2603:10b6:805:d::27) by SA1PR15MB4917.namprd15.prod.outlook.com (2603:10b6:806:1d0::20) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4352.26; Mon, 26 Jul 2021 04:56:19 +0000 Received: from SN6PR1501MB2064.namprd15.prod.outlook.com ([fe80::c143:fac2:85b4:14cb]) by SN6PR1501MB2064.namprd15.prod.outlook.com ([fe80::c143:fac2:85b4:14cb%7]) with mapi id 15.20.4352.031; Mon, 26 Jul 2021 04:56:19 +0000 Subject: Re: [PATCH bpf-next 1/2] tools/resolve_btfids: emit warnings and patch zero id for missing symbols To: Hengqi Chen , CC: , , , , , References: <20210725141814.2000828-1-hengqi.chen@gmail.com> <20210725141814.2000828-2-hengqi.chen@gmail.com> <95d1c440-bb99-13ad-0227-f9ab20a001f2@gmail.com> From: Yonghong Song Message-ID: Date: Sun, 25 Jul 2021 21:56:17 -0700 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.12.0 In-Reply-To: <95d1c440-bb99-13ad-0227-f9ab20a001f2@gmail.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-ClientProxiedBy: BYAPR04CA0012.namprd04.prod.outlook.com (2603:10b6:a03:40::25) To SN6PR1501MB2064.namprd15.prod.outlook.com (2603:10b6:805:d::27) MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 Received: from [IPv6:2620:10d:c085:21e1::10b9] (2620:10d:c090:400::5:64c5) by BYAPR04CA0012.namprd04.prod.outlook.com (2603:10b6:a03:40::25) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4352.25 via Frontend Transport; Mon, 26 Jul 2021 04:56:19 +0000 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: c456a2aa-8e22-4550-1be1-08d94ff1b53f X-MS-TrafficTypeDiagnostic: SA1PR15MB4917: X-Microsoft-Antispam-PRVS: X-FB-Source: Internal X-MS-Oob-TLC-OOBClassifiers: OLM:758; X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:SN6PR1501MB2064.namprd15.prod.outlook.com;PTR:;CAT:NONE;SFS:(4636009)(366004)(136003)(396003)(376002)(346002)(39860400002)(4326008)(66556008)(66476007)(86362001)(316002)(83380400001)(31696002)(66946007)(6486002)(5660300002)(36756003)(31686004)(53546011)(478600001)(2616005)(186003)(52116002)(8936002)(2906002)(38100700002)(8676002)(43740500002)(45980500001);DIR:OUT;SFP:1102; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?NEpkZjA2N3ZVRlNhSTB2MGdTenRycmZYUkx4UXVPZDB5VGJmaU5CRUV5SEpn?= =?utf-8?B?VEV2WUJhOFhteUFMTnN5aEw2emdEaWlTWmFQajB6bHRiWkhzRE5tQWIwYW5L?= =?utf-8?B?SFFVazZXVmU1bWM3UmVqNDh0b0FvdGdKVG1PUXh1cVhoQTZQSmI5Y2kvQzVy?= =?utf-8?B?dzFjbzdoOUN5SFpMTnorMnFhM0VzWUFNQ0Vac2JxdnhkSWhkajZxRGNSNXpE?= =?utf-8?B?WjM3QjA0b1YwcXBSZWlsamlaczJPZHVHcm8rSFJibldBWGJZOFlTb09pUDVO?= =?utf-8?B?ZnhCN3J2Z1NQSzFlRFFKb0s1UldEYmhsbkZEVGhoYklneXJGUHkwNTh4eFpa?= =?utf-8?B?LzB6ZWYrdnh2ODRtNEk3V0o5czd1bzhBUHpvWk13UUhGM2dCTXh5SGxjcGZs?= =?utf-8?B?Wnp1bVN2bWg0VXJlYS9YTTdBZ085L2lBNDlyYkxLTld3NVBuajZOaGw0RzZI?= =?utf-8?B?dXBWVlk0bndlRUtZdm16Z04rSTJIUnl5UXJYbVNWQ2k4NHVNYWZwK3U2MEZs?= =?utf-8?B?NFZqa1JKNG9uOVBTd1c3b2FOYytsNE81YU01UEMrN3FDTENxZ2dhM2FvZE5O?= =?utf-8?B?Q0ZzRHMxV2RRcGpmaFZQUFNvT1BuN2ZmbDJ3OHBRZkRJTVZNd1NOUWVwQkhO?= =?utf-8?B?bk55MmZkZVZra2dFUlRNVGp0WmRmd0RWYUtSbWdSeVNvdkoxWXdLQXJpSjlY?= =?utf-8?B?dCtlcnJvSnFjaC9LcXZCRE05WDkvU3E3SmFCMWEzd1V1bzZyR1BrbjNzaXNW?= =?utf-8?B?MlRWakllQXdZRTFyVTl2N05ZR1RDVGM3bDNocHVPYVRGL3JXbXhCb0VCU3p2?= =?utf-8?B?eVRBUlNwRWhYendlVS9Ta29CTElUUDY3bGk0b1ZlbjliSUErbmxpeE81YTEy?= =?utf-8?B?dXZnSkdTSDQ2YTlOVDEybzhWZ25aRi9GMmQxN2xqZk52SHorbXhTOVYyS0hk?= =?utf-8?B?R09Ld2FocVkrMkNOd3E0a3E5UnE4UnBveWtHbjdGa0pXaGdtakJtSVV4OXpw?= =?utf-8?B?RytkaDFjamc2NzBTTEozaFpybUtpdUFrcndWL1JDTUl4c3BLNGZxZHpzMzVx?= =?utf-8?B?MW1qK2dsOEt5bm1teFZLVzRtTHZEaG9UZjZtT1pJWmdLNnowNEVvdWJvb29w?= =?utf-8?B?TW1DQWpSLzVsSy94NXIxQldMWlJwRS9paVZtWFBqSzBpeFp6YmNaWTFCaVVh?= =?utf-8?B?bEhhSXRNVFVLb1RFUXNJWERHenBVVW5SYnNUTXAwMTd1RkxzS0NISjBoRGFL?= =?utf-8?B?aTBnclRQM01vZkNDc05jcDZZdUhVb1BJUHhjaXBIbW5mYkc4WUozV1Z5SWVR?= =?utf-8?B?RmFobXVCZ24zRkh4Q0R4S0doQ2pHaHhJUXV0NHAzSEtLRE5sUWlBZFpPQjNJ?= =?utf-8?B?NWpSMER6bGtwM2xTZnpVYUZVaGY1NnkzSytCVktMdmU4R1dueXhHVnZsdEpx?= =?utf-8?B?M0d2SEM4VUNUYkRUM0d1djJYTUNKUVFZcFQyTnVGdjhYUTVUUkJpZzBUWEpT?= =?utf-8?B?WkhoNzBVaUFNeFQ2Tk5QY01rUmM1UDMwSFNHSEZ4bTJLaGx5RytUdHdWQU50?= =?utf-8?B?ZkZOQkdJVko2cWNHK2JZbVJ2RU9qRFNVNXI2RXJlMnJjTW11NzJ1QTdRNzh6?= =?utf-8?B?SW5jOWlCMjBXajg2Zzlha2huQi9wYXJtZjhDWUhYOFN2ekFndTl6Q1MrUmJH?= =?utf-8?B?YVFCcVFHYWJCdHpHQzVERWx3elRxZDRjYUNvekFPMkZaN3h3QktlNkZsa0pV?= =?utf-8?B?bnJCcERPZnNvdysySlBPYzd5bVJ4MVE1N0E1aTFCQ2FKTjdJZWQ5ZlhXSmF0?= =?utf-8?B?cGg1YkptVEgrNDg5RTJ0Zz09?= X-MS-Exchange-CrossTenant-Network-Message-Id: c456a2aa-8e22-4550-1be1-08d94ff1b53f X-MS-Exchange-CrossTenant-AuthSource: SN6PR1501MB2064.namprd15.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 26 Jul 2021 04:56:19.7549 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 8ae927fe-1255-47a7-a2af-5f3a069daaa2 X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: pGTrvdjO9FzEoAuIto96UxoveT/1LTZHwT0+oF2fdugqv55snagPe1gMZL79iLsi X-MS-Exchange-Transport-CrossTenantHeadersStamped: SA1PR15MB4917 X-OriginatorOrg: fb.com X-Proofpoint-GUID: Kn-VeuQ37vTeYxKOWliFdmzXJ_CJcYZW X-Proofpoint-ORIG-GUID: Kn-VeuQ37vTeYxKOWliFdmzXJ_CJcYZW X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.391,18.0.790 definitions=2021-07-26_01:2021-07-23,2021-07-26 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 spamscore=0 clxscore=1015 priorityscore=1501 malwarescore=0 impostorscore=0 phishscore=0 bulkscore=0 mlxscore=0 mlxlogscore=999 lowpriorityscore=0 adultscore=0 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2104190000 definitions=main-2107260028 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On 7/25/21 9:41 PM, Hengqi Chen wrote: > > > On 2021/7/26 11:32 AM, Yonghong Song wrote: >> >> >> On 7/25/21 7:18 AM, Hengqi Chen wrote: >>> Kernel functions referenced by .BTF_ids may changed from global to static >>> and get inlined and thus disappears from BTF. This causes kernel build >> >> the function could be renamed or removed too. >> >>> failure when resolve_btfids do id patch for symbols in .BTF_ids in vmlinux. >>> Update resolve_btfids to emit warning messages and patch zero id for missing >>> symbols instead of aborting kernel build process. >>> >>> Signed-off-by: Hengqi Chen >> >> LGTM with one minor comment below. >> >> Acked-by: Yonghong Song >> >>> --- >>>   tools/bpf/resolve_btfids/main.c | 13 +++++++------ >>>   1 file changed, 7 insertions(+), 6 deletions(-) >>> >>> diff --git a/tools/bpf/resolve_btfids/main.c b/tools/bpf/resolve_btfids/main.c >>> index 3ad9301b0f00..3ea19e33250d 100644 >>> --- a/tools/bpf/resolve_btfids/main.c >>> +++ b/tools/bpf/resolve_btfids/main.c >>> @@ -291,7 +291,7 @@ static int compressed_section_fix(Elf *elf, Elf_Scn *scn, GElf_Shdr *sh) >>>       sh->sh_addralign = expected; >>> >>>       if (gelf_update_shdr(scn, sh) == 0) { >>> -        printf("FAILED cannot update section header: %s\n", >>> +        pr_err("FAILED cannot update section header: %s\n", >>>               elf_errmsg(-1)); >>>           return -1; >>>       } >>> @@ -317,6 +317,7 @@ static int elf_collect(struct object *obj) >>> >>>       elf = elf_begin(fd, ELF_C_RDWR_MMAP, NULL); >>>       if (!elf) { >>> +        close(fd); >>>           pr_err("FAILED cannot create ELF descriptor: %s\n", >>>               elf_errmsg(-1)); >>>           return -1; >>> @@ -484,7 +485,7 @@ static int symbols_resolve(struct object *obj) >>>       err = libbpf_get_error(btf); >>>       if (err) { >>>           pr_err("FAILED: load BTF from %s: %s\n", >>> -            obj->path, strerror(-err)); >>> +            obj->btf ?: obj->path, strerror(-err)); >> >> Why you change "obj->path" to "obj->btf ?: obj->path"? >> Note that obj->path cannot be NULL. > > The diff didn't see the whole picture. Let me quote it here: > ``` > btf = btf__parse(obj->btf ?: obj->path, NULL); > err = libbpf_get_error(btf); > if (err) { > pr_err("FAILED: load BTF from %s: %s\n", > obj->path, strerror(-err)); > return -1; > } > ``` > > Because btf__parse parses either obj->btf or obj->path, > I think the error message should reveal this. Okay, I see, obj->btf may not be NULL due to OPT_STRING(0, "btf", &obj.btf, "BTF data", "BTF data"), How about obj->btf ? "input BTF data" : obj->path The error message like FAILED: load BTF from : does not sound good. > >> >>>           return -1; >>>       } >>> >> [...]