From nobody Sat Apr 18 20:49:21 2026 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 049FCC43334 for ; Mon, 11 Jul 2022 11:13:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230362AbiGKLNT (ORCPT ); Mon, 11 Jul 2022 07:13:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54226 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230146AbiGKLMw (ORCPT ); Mon, 11 Jul 2022 07:12:52 -0400 Received: from JPN01-TYC-obe.outbound.protection.outlook.com (mail-tycjpn01olkn2021.outbound.protection.outlook.com [40.92.99.21]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9868583F37 for ; Mon, 11 Jul 2022 03:25:38 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=ETaxQ2rG7WjlZ1j5AqAWNYXMG6iNKb5pg7YLUf2OFssa9lFSi2tJyoXaFhol+xKq6SMItesTGQyxVeb/eY8wbHjyV/7hdAkkGyW8BvF3PpdL40JEyxduJ+6S82PFpSdauHEhSDyl3v9cLEwDCu75qYe/Ic5lLSR2E1vgjK04woY8et1HlqzzAoVhMcyExmhQqCtNc/Xn4fvH82waFEcKZjhXVkegcynmv+HjT3w+oDV8+xfktmldR7n/TqyO6EcDbR/IsA1tIfRf2A11XA9Vai6/x7r3nOndNT2yf8maLcWtgIhzW7MQdatQe8o8q17x2eAdbLdaqcLLs8lLyb6Otg== 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-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=NHZA5v+NXRrkqH8uxEGKYmNqaKSIJCbT6XfkIbDflVk=; b=ogAKPP6HlfR/PMmn0tLEmWTlij+oiWeXp0LjeuQYFtL4eEd5BDhVt6ePHlrk3SWPILHz+ar6cDW1QxKaciNgJG5rLv/d5/qx0FvT2RAmBepRQ6xnD/wTp2xzjRqFRA2gO8PCTowAfCJbOW/jWevZ3uNPQtl9PLygBhHqHmu7Jy/78dd20WGylZyv1rwi3WP7ISkcUGv4VGP2b0e8SI94dV+BlUg1X48MF8WLTZV7Icl5xemM4/xVqXvLP7uoeKUWCxiA6mIqAWCP+FWEutC0OBa5hx/SR+5cKDaNo+xlc/W7HVbFsVLgkNST3k2DTULU0niD58tFbnK8cHhr1MMrmA== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=none; dmarc=none; dkim=none; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=hotmail.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=NHZA5v+NXRrkqH8uxEGKYmNqaKSIJCbT6XfkIbDflVk=; b=HGkgwdSkaALLTgfFh26q73Z3qs9dM229e9YCpC2Ys0au3P/2FG07poDB6Te8APrTTyp69y22/JwQ8j1zXfhz+5nhGe5yid6iLPeBXZrdZSPBcxOe5rwvUlNiT3OlX7H/mdZIsMghCBysu85CXUT6kKhD+xqQlbI7F53yjd+Nitr8WxlXpka+xcT59bDTqkR6LUMCM0h42O9z8fKg8sxH3imD5/Oa2tdx6H6qYHZG4XfCvVVfr4aY0g+lT84RXAq5HmfB18jvmhZjsCWoI4B132GoD/Bd6IXV4dmNHm46QGwJq4f3l0ZBAEhA+Ys42Li3cR3ZTu47IoghsLoJnM99Yg== Received: from OSZP286MB1725.JPNP286.PROD.OUTLOOK.COM (2603:1096:604:1b9::12) by TYWP286MB2828.JPNP286.PROD.OUTLOOK.COM (2603:1096:400:23d::8) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.5417.20; Mon, 11 Jul 2022 10:25:36 +0000 Received: from OSZP286MB1725.JPNP286.PROD.OUTLOOK.COM ([fe80::5999:44e0:89f9:487d]) by OSZP286MB1725.JPNP286.PROD.OUTLOOK.COM ([fe80::5999:44e0:89f9:487d%9]) with mapi id 15.20.5417.026; Mon, 11 Jul 2022 10:25:36 +0000 From: "anquan.wu" To: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev, john.fastabend@gmail.com Cc: linux-kernel@vger.kernel.org, "anquan.wu" Subject: [PATCH] libbpf: fix the name of a reused map Date: Mon, 11 Jul 2022 18:25:21 +0800 Message-ID: X-Mailer: git-send-email 2.32.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-TMN: [cA8xopi+Vv4OKQesrdq5ig1NtTyERmpw] X-ClientProxiedBy: SG2P153CA0043.APCP153.PROD.OUTLOOK.COM (2603:1096:4:c6::12) To OSZP286MB1725.JPNP286.PROD.OUTLOOK.COM (2603:1096:604:1b9::12) X-Microsoft-Original-Message-ID: <20220711102521.2880073-1-leiqi96@hotmail.com> MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: 0153555b-10b8-4441-4680-08da6327b173 X-MS-Exchange-SLBlob-MailProps: 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 X-MS-TrafficTypeDiagnostic: TYWP286MB2828:EE_ X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?ZlhLZ0RrUU5KdktZSjlLQWJtbzJVRjZVL01rb00xcUFBNDRQNTNSWDZDTVlN?= =?utf-8?B?cDhBeEVXWWQ2RUJJZXI5dDB0ZkZ1MnYyUWRrR29oUS9QZHZidzMyeUtqeHNZ?= =?utf-8?B?enVIZ3YvOXNQam1tWVorZ3QybVVqSGN5ek5aVno4ekJQL2FpMWk3bHVSQU4y?= =?utf-8?B?UHRpN0psdHNDM3p5TnNuR2QrYWFmZmNNeHlaWWZPajM3WENUQnhMNU5SMFZ5?= =?utf-8?B?d05IaGwwMEZQV2xnUjVSOXZBOENZdFlKcDBaUTVjZStxOHl3SEVEa01sVjg0?= =?utf-8?B?VGZyZGxiaVhIZWYxei83YnVsOVJLSXFXVnVvaStZazg0eTlSZlFObXQvWSt5?= =?utf-8?B?T0Q3VXRLa3U2cmVZekdNbmswWU43Mm1PTHk4dlJSODdLcnAvVWNJeUZvTzVV?= =?utf-8?B?M0lpRUtvUXlDK3hLVWRLb2UrRlJPWmt5N092K3VzbDlHUC9KQWxPVXRjOFRJ?= =?utf-8?B?bEYrOGM2T1JtMExZNkVVakcvREdwMHYzZ0RNWFB5cEZ6WnJnSHdvK2ZPKzlm?= =?utf-8?B?c0FaZklJZ0hpU0VuaDlULzBFU2tXUFVMZnNvS0k5YnlKWVdXNFkwQ2I5NE9t?= =?utf-8?B?WkdzcGVmenlvZERSZllIQ3dBZ2l4ZkU1NFpnRnlTN0FURVZvWDIrQVY4REdO?= =?utf-8?B?SzhtZGFFTENZK3BVdGtmTGxXSXZXNUN5Y0ZjUkRyVk5IMkZDbkt4alZ1c2Zi?= =?utf-8?B?T0NVWDhzckdLbXhicnBaVVFDQktuWkl6OWM4SGJoNG45K0piZGtEdk9nQW1Q?= =?utf-8?B?a2xqSjdENW94U1I0L2xOTHhZUEkrV3B6TitqZXhNbTJiWmRTNFJHTzVUMmVL?= =?utf-8?B?NVNNeDZzMDgxRVhIdzE5TkdQa09UNkRrMEQ5REFkbm4yblY0ajNrZGx2SDFO?= =?utf-8?B?MWNzdnFEOWF5MXdYaW44eVZiOEZsOXhlWXNNT3ovYk1ydnIzdy85ZlJ4VWtS?= =?utf-8?B?UjI0K3Y3bXNtMDZRRkNMVzFnS3ppNitPT083cDdCdWZoV2RnVjEzMjdmM2Uy?= =?utf-8?B?MVA1YUJBcHBkV1V4MDNtS3YvTENzd0s3aVNKajduazNXMmd6Zk5RcTBCc3h3?= =?utf-8?B?SkZENEpJVU5nVit4elZzUnNxeXJaUmFxQnVvR25OZHJIVFQvbVF1aFBrMUxp?= =?utf-8?B?K1Q5T2dVM1RlcnJpUUpRdWtlTGpFaWZ5amY1QUlJcUxpKzIyWkVpRW8zVG9o?= =?utf-8?B?a3FuelVoOHJkVFNuWUJ4M3JyQzZRaWduL2NUekY5bnhjbmVxTTRwc3NXaHVy?= =?utf-8?B?U1JjM0ZyWW00ME5iNkFlb2o5NElkaTJKOVB3MDNQMitQNzY5ZnI3eENWQnl0?= =?utf-8?B?c0dDMXNZckJMYW0rd3BQNEdtTDdLaExFWEp5WEpPQUh1K3hyWTB6UWNFTDY1?= =?utf-8?B?a3FuMlgxaVB1L2RlZUo4ekpvUVF2L1pmTFFBVTB4MjI0Wnh4cW1JWWdZVzdP?= =?utf-8?B?MFFQcC9iKzlzTnhNdXR1a1RIR2Y1RkdJMVBhR1N0bXZnTTBlS3BJb1A4ZDFa?= =?utf-8?B?eEhZR2ZWYjA1MG9tdmo2Mjc3bEIyYUZvN0RXbGJuaFZhQ3VvUnB6VU9zdDFD?= =?utf-8?B?WTEzSGYzYUpEcXg5bllYNHcrMmF2dXNGYmF5enV5bDNiMDlrOXBaUzlFQW5n?= =?utf-8?B?VkhsZ0NjWnk0bnV2enpxbnhxUmpOWWNqaS85TmtIRHNhTTZ3UzlNZ0lNcWI2?= =?utf-8?B?c2pzK2hpd3JrS1NYck56QVlnWGhWejd1ZExmcWNzMWVrbjNnc2R2NDV3PT0=?= X-OriginatorOrg: sct-15-20-4755-11-msonline-outlook-05f45.templateTenant X-MS-Exchange-CrossTenant-Network-Message-Id: 0153555b-10b8-4441-4680-08da6327b173 X-MS-Exchange-CrossTenant-AuthSource: OSZP286MB1725.JPNP286.PROD.OUTLOOK.COM X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 11 Jul 2022 10:25:36.1456 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 84df9e7f-e9f6-40af-b435-aaaaaaaaaaaa X-MS-Exchange-CrossTenant-RMS-PersistedConsumerOrg: 00000000-0000-0000-0000-000000000000 X-MS-Exchange-Transport-CrossTenantHeadersStamped: TYWP286MB2828 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org BPF map name was limited to BPF_OBJ_NAME_LEN. If a map name is defined as being longer than BPF_OBJ_NAME_LEN, it will be truncated to BPF_OBJ_NAME_LEN when a userspace program calls libbpf to create the map. A pinned map also generates a path in the /sys. If the previous program wanted to reuse the map=EF=BC=8Cit can not get bpf_= map by name, because the name of the map is only partially the same as the name which get from pinned path. The syscall information below show that map name "process_pinned_map" is truncated to process_pinned_" bpf(BPF_OBJ_GET, {pathname=3D"/sys/fs/bpf/process_pinned_map", bpf_fd=3D0, file_flags=3D0}, 144) =3D -1 ENOENT (No such file or directory) bpf(BPF_MAP_CREATE, {map_type=3DBPF_MAP_TYPE_HASH, key_size=3D4, value_size= =3D4, max_entries=3D1024, map_flags=3D0, inner_map_fd=3D0, map_name=3D"process_pi= nned_", map_ifindex=3D0, btf_fd=3D3, btf_key_type_id=3D6, btf_value_type_id=3D10, btf_vmlinux_value_type_id=3D0}, 72) =3D 4 This patch check that if the name of pinned map are the same as the actual name for the first (BPF_OBJ_NAME_LEN - 1), bpf map still uses the name which is included in bpf object. Signed-off-by: anquan.wu --- tools/lib/bpf/libbpf.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index e89cc9c885b3..5ad52a8accd1 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -4328,6 +4328,7 @@ int bpf_map__reuse_fd(struct bpf_map *map, int fd) { struct bpf_map_info info =3D {}; __u32 len =3D sizeof(info); + __u32 name_len; int new_fd, err; char *new_name; =20 @@ -4337,7 +4338,12 @@ int bpf_map__reuse_fd(struct bpf_map *map, int fd) if (err) return libbpf_err(err); =20 - new_name =3D strdup(info.name); + name_len =3D strlen(info.name); + if ((BPF_OBJ_NAME_LEN - 1) =3D=3D name_len && !strncmp(map->name, info.na= me, name_len)) + new_name =3D strdup(map->name); + else + new_name =3D strdup(info.name); + if (!new_name) return libbpf_err(-errno); =20 --=20 2.32.0