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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 40D54CCD1BF for ; Tue, 28 Oct 2025 16:29:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:MIME-Version: Content-Transfer-Encoding:Content-Type:In-Reply-To:From:References:CC:To: Subject:Date:Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=YGFhUjjgQqU2cER8pLmZiTPCbshQvalu6WtZbhMN2E0=; b=bg7K/qF52LbXC5Sy78eAqJGNi3 rqh3jQ2zpFOs+++tb357FxpeljQaNwx9hDzOJ192BJ/6KBOQVVb3h48gbBn2RFqQjiiw2pr3yHmRO j0FcKexgKm2HKxH3FF6CKuTnW046cfnidTxCV3iztZCzXSxwlEPtV/Q/OzuamVjBdwVxNBhl9yqNX gFd6wCQVNupoOtPvVa5eQdwJ0zlmgnzbOxQq+thYrazTTT5dWV/f8JCrj1tFfbbU71N8HGqcnGqPS c7DECmsgq6exj/hcC+1o5BAL9fIyDnqKkdKQ/FElo5QH3+qKDSj337XpT8tQDnS24zqKE5xiT1Ghg cs8fQsUQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vDmZq-0000000GKKN-3ZDL; Tue, 28 Oct 2025 16:29:42 +0000 Received: from mgamail.intel.com ([192.198.163.14]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vDmZo-0000000GKJg-2PE0 for linux-arm-kernel@lists.infradead.org; Tue, 28 Oct 2025 16:29:41 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1761668980; x=1793204980; h=message-id:date:subject:to:cc:references:from: in-reply-to:content-transfer-encoding:mime-version; bh=jpP8oI3Mdg5tS+6VSROLI51wKbl4xmUxgfPT9hGwgIA=; b=Rcd0JoLIyYaZvuWDoA/D24U+2xpurQFOn3AW1VQ5qh4aY/mELBR2s1Zu OMCLnoYst7exSuZD85Ju7CcKCBNTYZ2F42ijLfH/U3kYyYlOSNRrqVPrM i9GPJXiIrNtW0oFRe4Na1PkVMXHwAMwoLfF9ywDOtMCK6n2J8Rg+ZlzpY hpwYB305cvNlYQLk7JIJJx3dbfRoEEtRmX5IbXCacfwwTpKpUWj6q5+HH +yBXQRnv6QAyK/B3Y7s/FQ6ooV3wnQsJZsuE1cSxarsp49XzWW1t37S0r XLY0p+t2OA/+0Ep0LX+8mm3kM2UVMnUA0dt+eO02i4PLhy4SSeZEMAoUQ A==; X-CSE-ConnectionGUID: AUvPO4BWTk+SVZYct9ALhQ== X-CSE-MsgGUID: nYbM2/32SHaaVTxMtaAKWA== X-IronPort-AV: E=McAfee;i="6800,10657,11586"; a="63812435" X-IronPort-AV: E=Sophos;i="6.19,261,1754982000"; d="scan'208";a="63812435" Received: from orviesa002.jf.intel.com ([10.64.159.142]) by fmvoesa108.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Oct 2025 09:29:39 -0700 X-CSE-ConnectionGUID: KsMYOKvXSlWid5UJxyMB/Q== X-CSE-MsgGUID: 4n4alf/JTruG/3pPyjvPGg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.19,261,1754982000"; d="scan'208";a="216054550" Received: from orsmsx903.amr.corp.intel.com ([10.22.229.25]) by orviesa002.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Oct 2025 09:29:40 -0700 Received: from ORSMSX903.amr.corp.intel.com (10.22.229.25) by ORSMSX903.amr.corp.intel.com (10.22.229.25) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.27; Tue, 28 Oct 2025 09:29:39 -0700 Received: from ORSEDG903.ED.cps.intel.com (10.7.248.13) by ORSMSX903.amr.corp.intel.com (10.22.229.25) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.27 via Frontend Transport; Tue, 28 Oct 2025 09:29:39 -0700 Received: from CO1PR03CU002.outbound.protection.outlook.com (52.101.46.63) by edgegateway.intel.com (134.134.137.113) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.27; Tue, 28 Oct 2025 09:29:39 -0700 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=FkmXY1HlJV4Dskesr5nkeg05fMONTKFIy4d4XibxRBP2ot0sv5nDRiJCg9QktfiTw2jQl+WFA7IsOPkKE0CRVIa75vrz9XIgFpikH6nA0hOlztDjM1LwK9NWz+tCA4eT1ETgIKGjOBbTY7CtVk8BmGKQIUuDj+kAlBfsdii8TJPgIPF+Q9lEX/1IyhJL8a/6IXHodIltXiS9zKmHzz7H05C76kdWjTqiT2utb2DscntJYkga2sEa2oxfpv3fgeNyUYK0pBiMnwjDtHzgZ4w23pQFHuRC8/p85EanmCxHr3ql58ouRN5RscRo+E2n2eA8fAJ4X7lMT+Uwa/+P5xy4Yw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; 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=YGFhUjjgQqU2cER8pLmZiTPCbshQvalu6WtZbhMN2E0=; b=Z1uqBTRjJAM8IavMwm7epUKpxDepW62IC1/ZLvRmocdyIXkXy7uIJn6FDQVOOrKbfKY1/TBtcdE+xxZ49g8FsFIXHwfFjMree7tbdqRFR4FW/bZw7JRZ8DOqt/g1Yk0bsM+5jKvTWYfnGSNai1Cte+ZAPaWpPfGMN6P3bn4zpH0qThWxOfdqVYBdrYvxbUpUyAl+cweykuBtfuGXZ85HchPFw15BrW68T0NMKElM2OpDk4EAaeqkCS98aWQw/9QfGPv+yu7N5vNn/97+UAWxuf9Pe9ondLfVJnLktrkJakkMj/yZLaleUShWsW4T97/hdPvYQbIenNh0b/8aJ/qrWQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=intel.com; dmarc=pass action=none header.from=intel.com; dkim=pass header.d=intel.com; arc=none Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=intel.com; Received: from DS0PR11MB8718.namprd11.prod.outlook.com (2603:10b6:8:1b9::20) by PH7PR11MB6673.namprd11.prod.outlook.com (2603:10b6:510:1ab::13) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9253.18; Tue, 28 Oct 2025 16:29:37 +0000 Received: from DS0PR11MB8718.namprd11.prod.outlook.com ([fe80::4b3b:9dbe:f68c:d808]) by DS0PR11MB8718.namprd11.prod.outlook.com ([fe80::4b3b:9dbe:f68c:d808%4]) with mapi id 15.20.9253.018; Tue, 28 Oct 2025 16:29:36 +0000 Message-ID: <5eb7ba26-8ecb-4a39-b9ed-961fffe4aa97@intel.com> Date: Tue, 28 Oct 2025 17:29:30 +0100 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 3/3] libeth: xdp: Disable generic kCFI pass for libeth_xdp_tx_xmit_bulk() To: Nathan Chancellor CC: Kees Cook , "David S. Miller" , "Eric Dumazet" , Jakub Kicinski , Paolo Abeni , Simon Horman , Nick Desaulniers , Bill Wendling , "Justin Stitt" , Sami Tolvanen , Russell King , Tony Nguyen , Michal Kubiak , , , , , References: <20251025-idpf-fix-arm-kcfi-build-error-v1-0-ec57221153ae@kernel.org> <20251025-idpf-fix-arm-kcfi-build-error-v1-3-ec57221153ae@kernel.org> <20251027205409.GB3183341@ax162> From: Alexander Lobakin Content-Language: en-US In-Reply-To: <20251027205409.GB3183341@ax162> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-ClientProxiedBy: DU2PR04CA0338.eurprd04.prod.outlook.com (2603:10a6:10:2b4::8) To DS0PR11MB8718.namprd11.prod.outlook.com (2603:10b6:8:1b9::20) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DS0PR11MB8718:EE_|PH7PR11MB6673:EE_ X-MS-Office365-Filtering-Correlation-Id: 78662264-a201-40cd-1d4e-08de163f2f17 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|376014|1800799024|7416014|7053199007; X-Microsoft-Antispam-Message-Info: =?utf-8?B?RE1hbTFJRnU2M1IyNEFSbnlIM1FISWlmNWc0K1RKNzlDZm93UFhEbGI2Y2la?= =?utf-8?B?WGlvNlg0b3JIQVNCUmJZMVFyUDRsMVlTbkdScWRJZzJIK1YrdmxYRDl3SU1B?= =?utf-8?B?b1BFRXBhRDNhZWxhNWtaWXhUd1RFOHpyU0xwVmFQM2lxeFFRMlBrK0ZQVDJq?= =?utf-8?B?eVAxenpmc08yMDZZWGFENm9XM0RzYUJDaXEvR0dRZElyYXJTWkhOZm9iRzBS?= =?utf-8?B?TjJZWnBwS28zUGQyM0VseUIzYlUxRFFUbGR6clh2REhsZ3FqT3J3UC9ualZY?= =?utf-8?B?bFVoN1lFOVJqM1Jha1JaWTlNUXVGeTA2UWVjbGhnSW5CVENFb0FXVmpneVdF?= =?utf-8?B?NXd6SjBBRHBzSjBxMFBGLzBHM3hMMHNTUW51eW5FREF6WktQd0kzWnVGa09T?= =?utf-8?B?Y1Vjd0lEb0dXMGEzVkJiNmJHazlKK0owa1dRekVaQk9KMkVyQ1dZdmtueGdV?= =?utf-8?B?SVFFcjBFcjZkNVYrdTZIL0p6MURDZDdDR0RxZjBDZUt5dUo1TWxQMkZENVFR?= =?utf-8?B?Q3M0SU5qSE9TOG1QQkF0Ri91SmRaUm1sM2ZHWXViL2U4czdZUFIxd0VJWjJM?= =?utf-8?B?UlZKenF3bW9sMmtVcTNQOTZsd2hiSkZ5bjRBUUpHWGJFRDBRM0RTMG1ncDlB?= =?utf-8?B?VFJrakZicWp2YlZSeDQvNU9pMEdIQlEreWlyV291Zis4b0ZPNFB0bEJuK053?= =?utf-8?B?WU5oc1huVE5iSzJ1dmlQenllMGd6cVNpV2FRbU9kWWlTZmd3UEdIWkJxK3Fh?= =?utf-8?B?T0xmckVNS01qRVN0VmlEM3N0azRNYzhrM2pDUGM5d1I2U0ZxdDIxRmNlM2hQ?= =?utf-8?B?L3YzYW5vN09sWUkrOE5MM2FxMURvS2k0WXcxdFJjdk9VK1hSSlQxZHo2UjlV?= =?utf-8?B?a1YvVnNIQmZ4MjBmUzc1QWgxT04zdHJva2RCS2EvdDlHd0JSb2JYWjFMUis5?= =?utf-8?B?ZzdGSkJ4UC91b0cvSnJ0b0tFQzFLS2l3enU5VFV3S3lVaWJ6Qy9LbTVtS0pL?= =?utf-8?B?NHNYeXozSU5maUZDWXJMS1ErMFZsZW1NNG9XSnV6OEsyTHUvUEt3ejVsWnQv?= =?utf-8?B?WjAxUkp3S2hmRGs0QzhUMzdOQlhFRzdjd3RtL2QzeU8zZWoxK0hLRnBFSFpL?= =?utf-8?B?SGN1OHh3RHlnY2dVbGZseG9tY2g5Q3JQUE05LzIzUnduVU90RHJoMHlEc3FR?= =?utf-8?B?aytVL2xqcWNkY1FyQU5HQ0lQUm1aaWs5T0VtNDdDRnhubEYyKy8yVG1jUXlV?= =?utf-8?B?UVlZdkZ3bm5UZ05abng3cEZVNEhWLzNQTU1LTWY0NlpoNG0rM1NFaUI2RkNw?= =?utf-8?B?NDRYYTNHeTk3NE9XSkRMd0NyaTNocHVoNjVPb2s1K2pNNmw2QWx5dnBQR3A0?= =?utf-8?B?bEczNHBleldXU2ZFaVpQQ2JKcWNvSFJaRk1Sb2IrYnNwcFc4WVEvYVlJNGho?= =?utf-8?B?L2RCTHNzVHVrL3Exbmp4R0dPT2dpbUt2U0ZuRGd4aUlDemJEWVp0Smp5anBr?= =?utf-8?B?UTl3R1p3aXVOR0pIMVFucjVQS2lIdEVaWEFncVYrd2xzTUZlODhRN2xqTlJo?= =?utf-8?B?aUJUZXArb1lzV3NzaFhSUmM0L3F3c2RvODFyNDByMzRkL3BiNEZaWHQwNHNX?= =?utf-8?B?VkdVVGEybUl5UjRFQk8weDhPWXlxSUI5b3FTQmJSOFB0QjZpL0pIY29ObzN6?= =?utf-8?B?T1lWWDBkY0EwbDRVWDg4eEQ5MGxOc1VKN2NhUUlsZEFDbHB3cjhpTWlVY1Vo?= =?utf-8?B?U3ZvL0xWaG1JK0F2SUdPU2t0R1JKZVdyMVdGbFhqZXV3WW5ldmQ0TVNHWmNR?= =?utf-8?B?VHlHeDRrS0VvaE45T2hGL0FzM2JhK2FjODZ3NUxJbzc3VzE2b3RndTczdWc5?= =?utf-8?B?aFh1OFVKZ3BTeUZBREJ0Y2xGcVBYRnVwUHd3VnhxcHRQVXl0SHNBbDZUZEVi?= =?utf-8?Q?6LOYF0j6XP4HR/1B/TaWJR86STGPChCB?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:DS0PR11MB8718.namprd11.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(366016)(376014)(1800799024)(7416014)(7053199007);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?ZWJJenlKcXZHZ1dDTXpVc0dDcnBGYk8yckx6YkwvY3Nxd0IzZitsa1RaTkFr?= =?utf-8?B?L2FZbHRwT0ozbjNFZXNmNy9sYm9nRGtMeCticC9iWVVWZkpENXBvSzY5MDU5?= =?utf-8?B?VEc0YnZBdDc5U0FCT05HenhpWXc0R0YrR3J4TFlNWDBWYW1vSHFySGhpZUI5?= =?utf-8?B?R0tWa0wwU0Ftamg3SUxwdW8xUmw5ZXdDRDVwNWR2UUxUV1UwcUJIYkgwUVVB?= =?utf-8?B?SnNoTTNiZHVwNjZKRVFQNVc3ZERhUXUyVkFPZ1puS3JaYUFtcGZNeWxkV1Br?= =?utf-8?B?Qm43WlROcHo1R0FuU3hvYWpmMWU1NmNyeGJYL1RlSXZhSC9jMHRLcS9GMVBm?= =?utf-8?B?OHZJSmQwMTloTGc5YjdDMitabFlYc0szOWZER3JmZzN6R3pweXZpeUY4VGlt?= =?utf-8?B?Wmk0akxPNjhxQ3o0RktOTDFBOS9Sb2M0Sm82UVJteVlSNDRzcTdCbE50TnN3?= =?utf-8?B?bTNTSVExanZubjlvWmpaQTJDakhrYWI3WUNZc1NmenZLV2pZRFVpcm04ekNq?= =?utf-8?B?RGZ0aThCZCtITmtjdS9iRnpaUlpmNzRUYXJkZ1pseXVDQ1lad3IyWkFaZXBi?= =?utf-8?B?SUtKcit0NDR6dFN4Z2RRRzBGUU5GYXg3WE5LR1dqOFRiMU10aXdUUnRhN3hl?= =?utf-8?B?cEtWMTNINUM1VDZqL09odmFOZEZrT054azd3bFViSFM3dkM5LzlEbnIrVWJU?= =?utf-8?B?SjVuL1JPMnZYSTA4SDVSejVHRUlxSmF3WXJUVjNObDd1TEZDQmtDYTh2Qmhq?= =?utf-8?B?OW9aUkZlalpKRXlqR2pwK1NnRGZrdlAvSGRBQmIwR1ZUZlBEMmgraTU4NUpB?= =?utf-8?B?L2tFREJ5U3VLcTZudUM0dXhkRm5nK1ZmRGFHT3UvL3RCaUNkNWlYZUtaVU5M?= =?utf-8?B?SzV6NFF4cEdHNTdORWxTRzJveXF0aEdoOTZLaDhLcERQN0VCMXpmeWRUNFFX?= =?utf-8?B?d0trVHgvNWl2MmJ4VFRzK2Z4anZCUWFOTzBlbGNMR0ZhdnlsOFBvUmlrdjlL?= =?utf-8?B?cm9XYUgzS1pXaS8wT3ZmMXFDbmlTRVpza04wRkNlSUVLVXhlQ2RRWGhzcGNB?= =?utf-8?B?MFlYeUZGS2RrUkczbGY3UXBmKzNuckg0YTJGL0djREVNM3VZNDVxb2hybzJ0?= =?utf-8?B?L1Q0M2lCRUdFSXVRZEYxeGpQQjhZUkEzS3pRU3l5bG5GMVprQjhDbTNZWk93?= =?utf-8?B?R3owWUZFbFRsWU5WamVaRy85OEU2MVFaZkVrYjBmK0NGdkswM2JwcU1kKzN6?= =?utf-8?B?b0RBSFVUbG1wSm5QaWNsdzRTdHM2djBCQ1l3Um1TTWJyQXN5MjRDeTNpbnox?= =?utf-8?B?Z21HaVNCajJmY2h1WmFWSXRQK0FwK1k0STlycHdHTUNwZ2JWSmZKeFU2aXJq?= =?utf-8?B?enhHUDVqRHVYTkkxNFRDbnptbmgvNitRY1lsQU9TYWVKakM3MjczRjFFTnlk?= =?utf-8?B?MG92bVBFVTdEdzZDNVpqbVdCRU44STlleFpmTE5PS3pCVzlqVE85ZlJqVFRR?= =?utf-8?B?WGR1bzZhaGpqNVJXUWVMdHZQTkRZUlpLTzduZUUrank2ejQ5d1EzcGM0MzFY?= =?utf-8?B?SVA3VU00RTBVUE5KMHAwdXpuTFdmZjEweExqdzROcFJyOCs3T0tLbjVJOUo5?= =?utf-8?B?clh2dGtrQ01vVW0vOUdEelc3ZkZhemMvT00rNnZ0dkF3UkZ5Zjc2VXZXeFli?= =?utf-8?B?M3kxQnl6UmVCYXJ5Y2pRSEplbU9QQUVQTG9DRU5oTHQ1TmkrWmlSN3BlbFBq?= =?utf-8?B?ZUVoQWE2TUxKdFNEd0R6bU5sVjRZY1gyeHVkeFR2a3lUcEtvV2VpbjhmNjI1?= =?utf-8?B?Z01OblYvSlM2cHlQSlY4b1M5R1FvbktXbWtTTUdVOUF1bjhVdk5BRGp6Mkht?= =?utf-8?B?OVJub0xwWVlQREE4akhkWEFjWkRZak80NlJZelZwQTBpejdtL2VvSklTN1BR?= =?utf-8?B?OTJ4OGVLZEI3OG1aSlVRNDBPdU02NisvZHFkcW9sbTBGY3o2Q2ZiTzIzcjJP?= =?utf-8?B?aUI0ak1GcUdoaDFKQ3gwQjQzZnd4SG9BSHdubURMd3NNL2xaS0NuSmRkdkhr?= =?utf-8?B?M2tEVllPcGFtVmxLbTAwdTlEbmMyV0RVSzRROURWK3FJSXBldEZyQWJ3QlY2?= =?utf-8?B?S2l4SG1zaFFBRmYwaGtHeEpQaWdjMzNZMXFOY0pONHk5K21uVlA1NWVCZXY4?= =?utf-8?B?WEE9PQ==?= X-MS-Exchange-CrossTenant-Network-Message-Id: 78662264-a201-40cd-1d4e-08de163f2f17 X-MS-Exchange-CrossTenant-AuthSource: DS0PR11MB8718.namprd11.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 28 Oct 2025 16:29:36.4946 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 46c98d88-e344-4ed4-8496-4ed7712e255d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: DbNB6qsFRrVeIlQGCIDm0J+exKEwF9KGKAEpLECV5APqiH+/yU7mHrFqYCvc8a30ALAIEN2pYuKRmLIQXVv+2aKOfd2+T5NpRYhuyRazZTk= X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH7PR11MB6673 X-OriginatorOrg: intel.com X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20251028_092940_638270_93E57107 X-CRM114-Status: GOOD ( 25.54 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Nathan Chancellor Date: Mon, 27 Oct 2025 13:54:09 -0700 > On Mon, Oct 27, 2025 at 03:59:51PM +0100, Alexander Lobakin wrote: >> Hmmm, >> >> For this patch: >> >> Acked-by: Alexander Lobakin > > Thanks a lot for taking a look, even if it seems like we might not > actually go the route of working around this. > >> However, >> >> The XSk metadata infra in the kernel relies on that when we call >> xsk_tx_metadata_request(), we pass a static const struct with our >> callbacks and then the compiler makes all these calls direct. >> This is not limited to libeth (although I realize that it triggered >> this build failure due to the way how I pass these callbacks), every >> driver which implements XSk Tx metadata and calls >> xsk_tx_metadata_request() relies on that these calls will be direct, >> otherwise there'll be such performance penalty that is unacceptable >> for XSk speeds. > > Hmmmm, I am not really sure how you could guarantee that these calls are > turned direct from indirect aside from placing compile time assertions > around like this... when you say "there'll be such performance penalty You mean in case of CFI or in general? Because currently on both GCC and Clang with both OPTIMIZE_FOR_{SIZE,SPEED} they get inlined in every driver. > that is unacceptable for XSk speeds", does that mean that everything > will function correctly but slower than expected or does the lack of > proper speed result in functionality degredation? Nothing would break, just work way slower than expected. xsk_tx_metadata_request() is called for each Tx packet (when Tx metadata is enabled). Average XSK Tx perf is ~35-40 Mpps (millions of packets per second), often [much] higher. Having an indirect call there would divide it by n. > >> Maybe xsk_tx_metadata_request() should be __nocfi as well? Or all >> the callers of it? > > I would only expect __nocfi_generic to be useful for avoiding a problem > such as this. __nocfi would be too big of a hammer because it would Yep, sorry, I actually meant __nocfi_generic... > cause definite problems if these calls were emitted as indirect ones, as > they would not have the CFI setup on the caller side, resulting in > problems that are now flagged by commit 894af4a1cde6 ("objtool: Validate > kCFI calls") in mainline. It sounds like it could be useful on > xsk_tx_metadata_request() if we decide to further pursue this series but > given we could just bump the version of LLVM necessary for CONFIG_CFI on > ARM, we may just go that route. > > Cheers, > Nathan Thanks, Olek