From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from NAM12-DM6-obe.outbound.protection.outlook.com (mail-dm6nam12on2082.outbound.protection.outlook.com [40.107.243.82]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C72832D3229; Fri, 15 Aug 2025 09:41:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.243.82 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755250894; cv=fail; b=knEQ1bp7ZjKa1jxPRsvBKG2SjSAmDel/vCmxxVl6VnPfsMs8ahYXlsw2HsXR8zVAAXspuw8c7Xw28yKf7br+yx/AnQOdx0rfDFnotSEiAqKw+LPKNClnQIA2nM3YKvtg1+ZSndKwmpcIHD6Wmk5hr7GYplk6cbKmL5jRio48ALg= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755250894; c=relaxed/simple; bh=tRm3zuVCOzgVASz3Gfbu0M5zy37coAalodmspir7Vdg=; h=Message-ID:Date:Subject:To:Cc:References:From:In-Reply-To: Content-Type:MIME-Version; b=c0bmiG75GTQVgAYiYuaRagLjRx5E+J9pFoAxXeHiOAktif5QwUmqwcNCvKd0uHsDPi6uAWlI4fj+fAgDxIfw438bOdievz3hIwdu5o4XaOGnsd4vUDg4wtdu4Bj6k67CqgEzyRK6XxnGYMbMbOYDaqTQJ4WnMDKqnRZEKcbzSVA= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amd.com; spf=fail smtp.mailfrom=amd.com; dkim=pass (1024-bit key) header.d=amd.com header.i=@amd.com header.b=v5lYIwtx; arc=fail smtp.client-ip=40.107.243.82 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amd.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=amd.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=amd.com header.i=@amd.com header.b="v5lYIwtx" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=BE4jplk5Qr+qNJot5EivIzZukBUU2SU6eA6gSclXoesZTf4jDN57FahrNf7uA4gQK0UCG+PjkICAiFBsuP96mWPE/64ZQT5LLiSddFqCAXSf2g++51SCyEb2zfYAhFIDlDnhydDyMZ1CeVsBpyXwHTFZPHKXP7c6e4HPSMzmy3kOp4XwCtNK4c8ZkwUYH//cJaGUiAkbAD+1VhNJ7puoBZvmA9mkbx9831ScMtJjrEieB34Ey49HvOywLfXnvpz+ElGQRicnMvJkswR0ML3aHLpK8f3s//iR3RNt/50CB+AczWfa3QHkxYYn9/jRzK9h442NG9YMphT2OtFMMZceeg== 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=4rqbVsKPamDtry5QTNDvqP9qgysC+pTr/eUEJ/qd9pg=; b=MqIdVNMeZAYqnH2NOxemjB+kCR3F+UvrhMwss+K7+YMx8AaxiGhunr484WFekJF2wp4FvbSyKi0qsudEbAGQA/w83GpkV1UKtpE3STwA46RIMbkl/pU/CT+UpU3E6LAc0aZweO5//5+bQhyaAHx0m+e+AN/XtUoJxJ1tEJdkUnz+G1vM5bkbnYJzm9b+/J3Ddi8rYVQ9WejdvOwAQpT9qxzVhyAgCwu+JvH1/+YMKHbw6Mz9X9RZdA8IiUGwUbIxZQsEexYTsnySD00LTg/54H6JHbh1tmRIWzX2TlXOR5VyYNDHB+MnewQ/Y2shXe0f9XFsWtqO1lbofJRbMEGlLA== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=amd.com; dmarc=pass action=none header.from=amd.com; dkim=pass header.d=amd.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amd.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=4rqbVsKPamDtry5QTNDvqP9qgysC+pTr/eUEJ/qd9pg=; b=v5lYIwtxlhOMKY5iGpnkXCjo0p83ynGGcoOj7obIjx1oB569Z2zt9xvEyDyI0ebq1HCRMYe022bL15Owq61j3BUqxGDpYKdoB4R4RdjAbw4/3VLyzd+5sdSI1aXzBRPyXFl6D/Ql6WpHrVVgojztNVMdkVVwBqG+CwBGhguaZGY= Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=amd.com; Received: from PH7PR12MB5685.namprd12.prod.outlook.com (2603:10b6:510:13c::22) by SJ0PR12MB5611.namprd12.prod.outlook.com (2603:10b6:a03:426::17) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9031.17; Fri, 15 Aug 2025 09:41:29 +0000 Received: from PH7PR12MB5685.namprd12.prod.outlook.com ([fe80::46fb:96f2:7667:7ca5]) by PH7PR12MB5685.namprd12.prod.outlook.com ([fe80::46fb:96f2:7667:7ca5%5]) with mapi id 15.20.9031.014; Fri, 15 Aug 2025 09:41:22 +0000 Message-ID: <0b963b02-dec0-4bf5-aea9-dbe3050716ee@amd.com> Date: Fri, 15 Aug 2025 11:41:17 +0200 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 0/3] udmabuf: Sync to attached devices To: Andrew Davis , Gerd Hoffmann , Sumit Semwal , Paul Cercueil , Vivek Kasireddy , Daniel Vetter Cc: dri-devel@lists.freedesktop.org, linux-media@vger.kernel.org, linaro-mm-sig@lists.linaro.org, linux-kernel@vger.kernel.org References: <20250814161049.678672-1-afd@ti.com> Content-Language: en-US From: =?UTF-8?Q?Christian_K=C3=B6nig?= In-Reply-To: <20250814161049.678672-1-afd@ti.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-ClientProxiedBy: BL1PR13CA0153.namprd13.prod.outlook.com (2603:10b6:208:2bd::8) To PH7PR12MB5685.namprd12.prod.outlook.com (2603:10b6:510:13c::22) Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: PH7PR12MB5685:EE_|SJ0PR12MB5611:EE_ X-MS-Office365-Filtering-Correlation-Id: 2805e898-e5ec-4740-b3e3-08dddbdfe4bd X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|7416014|376014|366016|1800799024; X-Microsoft-Antispam-Message-Info: =?utf-8?B?MGVrd3MraGZ0UGJMSzR4OTdjVjRCNnJsRW1qREdoTk1xUGVneFBSYjhRcUpi?= =?utf-8?B?VzBsNDN2QmZFV1RGb2huZU52d1B5RWhlNkRobGQ4UkN3YjNOOS94eDBscDdC?= =?utf-8?B?elEzaEgxcDZTT2RGZzBtb3k1V1hEQTdmaHZxU293eHhxZmpSVDZ4WXJQV2wz?= =?utf-8?B?YXBRMnA2QWs0WVBCL2UyZUsxbmFJMzFYZnBPWnNnOFM3NGZmL0RIaUg0U1Ni?= =?utf-8?B?TlJBTk9Uc2tScjJ4NTMxTkZwS3RGdWxNRFhyc1ZmcE1xaUp2N25RS2pMWlVq?= =?utf-8?B?Ty9wUEdiZWdHY2p3Y0ZNNS9RWjBiWVVMQkFjU3k3UnRXNzVUQm9qYjZRb0JY?= =?utf-8?B?L2tITUJsTVZLN1FLenA2QVgwMXZBc2p4cWJQMm1Qd0owMWhKMVRvNXYwTkVH?= =?utf-8?B?NUpjTTBoblBNRFBVNW9ucU94WTVFVWZ5Z050NnVNQWNtWUlrTmxnVHcrMGFJ?= =?utf-8?B?L3plUGt5c0NYUEVwa1k1Ujh5cmMwblRaYlYzN3I1akgvK09STWF0YVBUc0lG?= =?utf-8?B?K2o2SllMclV0dCtkZTZWd20vZTVML3l2M0J0SCtMNzIvSlJGcy83L2dVSzZ1?= =?utf-8?B?SDY5UitJUWJrbTJqWHFUbkRjTGJ1cHFDY09hbW9Dd0JBL3Z4OEd0Uk82c3Rs?= =?utf-8?B?Q2FiVmRSb1hNbTdOVmI3K1pXajdQbzJ3WFFROFJjdkREeVJqeTVxaERVdUJR?= =?utf-8?B?NFhha3N2UnBTVElSQXpqR3N6WkFNV0dQWlo3eFNsRG9reUE4NmFscW4wcjB5?= =?utf-8?B?UURabWV1ci84R0drYXhIU044R2J4M2hpeHgwZzZmTXZYdWg5ejNNNk5LbkZF?= =?utf-8?B?VjI1MmVWQmJjVzdOaTlzdEdnelk5RzE0K1l6WkI0QUErejRLUmRveHJLSkkz?= =?utf-8?B?OXNTbFdwREtLNTdVL0c1NEFJY0x6UGZmOHZHVi9sVUIvcVo0WlJXWWZuSC9k?= =?utf-8?B?bkxndyt2aS9GVkhGd2ZqVjFQQy9QT2dOdHFJdkxkU1ZydDBpRFJkN1RTNDVo?= =?utf-8?B?ZkdXYWRKMXgyd0VsTlBwV04zK2xaVUhEYy9OQnpFSW9ET3V1cXBlUjBTNFBa?= =?utf-8?B?WWFQS2xqK05menROZXRtNUZHcE9tM3FwZ3FUdlM1a0xndzZ5SlpHL2RMUm1V?= =?utf-8?B?MStTeUZDcFdHN0gzbDZoUjAxRXh3K0tnakpBcm5wMnc3K084RDY5anB1U3li?= =?utf-8?B?OUs0YllNMVFWYmdNOWZzY2dnQ1hESUVtKzd2cVpueEh5MnlJTUNvSU5vNWVw?= =?utf-8?B?aEN4Ylp5YjJLcVQyUDVjV2xwTms4MEFUM095aXJRQjBtang1ZENMY2cvUk90?= =?utf-8?B?Rmp2S0l3TGZLMFJRZzNxbUtxQVRYV0NCOE83bDZCOURUMC9NT3NiclZ0OFZZ?= =?utf-8?B?RUlwUDQreFdhV3BpMVBuUGt3WU8yemJBVlEzOGg5YThIMDVaMW52WXQ2NHdi?= =?utf-8?B?Zi9Tc1ZGNmVma3AwcE1LRDBTUVNXQXgwbzU1MnA4MUFHVUNVSzZjM0tGdEVR?= =?utf-8?B?VWR4VnFxaU5LbjYvNzFKOGMxTXpsek9nazNTNDF0WFBNa2hITnpoL1FqcUk5?= =?utf-8?B?K2hFNXpEOTJJY0p4UVN0VXVNNU5CeUxUM3kwckU1cVlwbVQxMHNEbkM1TkhB?= =?utf-8?B?dTlDd0pZcXd4UVoyUTErOVlDY1kzZGRCOUc1N3hWV0FUYTJrOUQ4bDZuQ2dW?= =?utf-8?B?U2dVbGwvK3ZxeUFXa2VQUDlDRXJnYy9xallBalN1KytTMGNKcHlFZjE2L3BZ?= =?utf-8?B?L0FVTDJ5S1FYa2lvRk5vNTdSRHZZWXlIRStIQkR5VktNNStpL2I1K0pDMmFF?= =?utf-8?B?M05hTnV5UGcxOUwvYjVVTXd2cG4vaGdCaEdCZXQ1L3BLNkQ1S25tc05JK01y?= =?utf-8?B?TnQ4b3ZDNlVrNmJVbmsrMTlLcHlNN3Zoa213SE5ObzREUGdvL3NzWU5PSzlP?= =?utf-8?Q?axWaXDd+2AU=3D?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:PH7PR12MB5685.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(7416014)(376014)(366016)(1800799024);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?d3FHYWpjUURyN3hscXM4SUlyMGNTYTh4NXdWdCtQWkhPVVN5QmsxOEYyOVhX?= =?utf-8?B?Sm5ZcTlTalVrTVZ3YnVVTFAvUEhQSFExY2IrR0N5ODlNNFl0RkNiRTAwbHVT?= =?utf-8?B?ZzNra09YaGZMc1haQW9aUU5abUtZNkRBSDZIT3RLWCtFYU1neTc0emtOaW5U?= =?utf-8?B?bkd2Z2ZXSnVZRm9RQTZJMmtkdFBVNEtOUEdVN0ladXlwdDBZMWx4VitwTFFU?= =?utf-8?B?TkpsdXVtYTEvbmRNTUJBYzhxVmpFa3RCa0VObmg5MU1UNHJMaWxWMUZHT0lV?= =?utf-8?B?cWxCYzBoNUJjdy92UDFtUnNKUEx2UlF2ZzkyRjNGNjczRk9aWWlUMVJicENZ?= =?utf-8?B?MGVTL25jUnFDbkd4cjhlck5kSWhJMU8yY0dLb1NFY1ZWVitHOGtIbDc4Q08x?= =?utf-8?B?OTZyaGF2akNQZU5aY0hJTlphbWFTSUl2b1ZMYUwxc3AreVBWdmFGM2lOSDZu?= =?utf-8?B?SkI1NUlsVEVnRXJ2QTZjbmZSYm9PUUsvbGxSZ1ZRSU5mRTBOblc5TkVZczVw?= =?utf-8?B?YW1QNktZckJybm5jd01HY1FQS25DbkZCMDVONnJ4NWIrcXpGZG1pV3BBaWhn?= =?utf-8?B?THVwMkw4WGRsUE5tQVFkTnN5WGdzM1JKWjZmbC9wQVJyRVJHRks2eCswUTlP?= =?utf-8?B?azFPb1o2a284Tm1VVUIzanhSQ0JGdmM3OGpZOEpoTE1hTSt5VER4dmtMeWRX?= =?utf-8?B?TVZpaE1odHg3eUZ5Y1JBcVBCV1U0UlVEaEpZU2xrMkpxNkQ0R29CeWZoamtw?= =?utf-8?B?MCswK05zU1lMUDlBTVBlUDFibzFUYyt1TGkrNFRnRS9MK2Q4WDVicVhSQ1lX?= =?utf-8?B?YjFLazFrRWVCSlVxby9qdmdvTjJzNkQveGI2UHFMTFZCZDFBM0FydkNDS09K?= =?utf-8?B?MkE5eGZucksvZExqdkhyOERHUG9waVpGdWswK1c4M2tuck9yZnJVUmg1SFlW?= =?utf-8?B?UldaUERNYU1aQVlwb29EWVZvd2V3WmxtQXYyVXVKaUhpZU56OTFVVlBMMnlw?= =?utf-8?B?SWRDcmdVSTdZL1o0cXdVUHRQVzBJT0xzTEtDZTd6eUZCYkpRMjJ6UmVEOWF1?= =?utf-8?B?Q1F4YnZaT0w1ZXI3dkdncmlsQ0tpYTZoeHFMalJYTHF5RTZXNVhtSmVvdEIw?= =?utf-8?B?T1BYNi9xalZibENiRkdMeXRiNk1EdVdCYVkxNmE5S2phUnY1MEpTM1oxL3Jw?= =?utf-8?B?akJNd21iMGhzZjcxSUp2enI3MlQ1UDNSNjRBMUVaRzZhUWErVHdjd05oV2lR?= =?utf-8?B?cFdOV2lHakc0Tys2dzYxWEFRMyt2cXEvSFRIeHdDNzMrNCt5QitKZmQ3bVdS?= =?utf-8?B?VklIbXhndjgvR0haMGpIcmkvdHplZURib0ZIdGliV2tiZlhpRGt5STZQSXds?= =?utf-8?B?akxBUkxBWFkrSFd6dm1RdWRzSDJUTEdBV1I0eEhQQXQvMUx0WVRJd3NyakRG?= =?utf-8?B?ZXBPZXE1S1FNOU84Z2J5b0pXRTlEVU4wTURUVVNuNWkyRWYwK3drc0I1NmRL?= =?utf-8?B?UFczRTVTWllnMUx6QXNNTGVvMXFCR0ZQZk1vV1dRNG5OMkMyNy80SHdDVUJq?= =?utf-8?B?UFo4amsza2ZaSmJ5NThBMU94cWZ0b3RKNTlLYk1KUHR2SG5SUDdyZDhSUnAr?= =?utf-8?B?U1g3MjZMK1lXZWREOG83bFhjN25JOW1Yd3Y2N1hRVnZZbHNhdXpoeEdUVFFP?= =?utf-8?B?Q3JpVkxoZkFMZzEvczZ2T2o4ZWJOeGJFWW1uTkQ5OFZFMldhQ1ozVjF0elFD?= =?utf-8?B?cVdMQlZrZ2dhUWlUZVU1SndtMTQ0N0xuVzFvNEVrN2xFWGhmRW5yWE14dXVC?= =?utf-8?B?b0lMeVVYRlhKOERENHEzdy9JU1h3V3ZmUXgrM3VyNXlaTWh4UlBEcmNIQUVx?= =?utf-8?B?Ulg1UjdPdGJMdllKYVlLL0cwUnNpZW1zSDUvMkRQU1BRcWwwVGt2Zk5RU21m?= =?utf-8?B?VVA3U2kzRzkrMVY3NVM1OFhId3J0NS9zSWtnN3JKK2lCU0RSaVZBT1g0SXJF?= =?utf-8?B?WXplTzFqeDVidHJKUWdsTEQ3T3NkaWFYSE9TbDRiU0E0Vzk5N2cyUTVaZldk?= =?utf-8?B?YWNiTERMbkRuc01Nb1IvcmswZ05OT3FIbWZYNUNBU1Y3T0FibmNvYjc4S0I3?= =?utf-8?Q?rBufG3G/9nG1NPvD+tgRQ+iSv?= X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-Network-Message-Id: 2805e898-e5ec-4740-b3e3-08dddbdfe4bd X-MS-Exchange-CrossTenant-AuthSource: PH7PR12MB5685.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 15 Aug 2025 09:41:21.9685 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: 80+k9/jsT6cv0w9eEI7PYI8mJgWxDEStSWU9IJaMGsZf+U/q6Ygpw+Iv51yCU98U X-MS-Exchange-Transport-CrossTenantHeadersStamped: SJ0PR12MB5611 On 14.08.25 18:10, Andrew Davis wrote: > Hello all, > > This series makes it so the udmabuf will sync the backing buffer > with the set of attached devices as required for DMA-BUFs when > doing {begin,end}_cpu_access. Yeah the reason why we didn't do that is that this doesn't even work 100% reliable in theory. So this patchset here might make your use case work but is a bit questionable in general. udmabuf is about turning a file descriptor created by memfd_create() into a DMA-buf. Mapping that memory can happen through the memfd as well and so it is perfectly valid to skip the DMA-buf begin_access and end_access callbacks. Additional to that when CONFIG_DMABUF_DEBUG is enabled the DMA-buf code mangles the page addresses in the sg table to prevent importers from abusing it. That makes dma_sync_sgtable_for_cpu() and dma_sync_sgtable_for_device() on the exporter side crash. That's the reason why DMA-buf heaps uses a copy of the sg table for calling dma_sync_sgtable_for_cpu()/dma_sync_sgtable_for_device(). It's basically a hack and should be removed, but for this we need to change all clients which is tons of work. Regards, Christian. > > Thanks > Andrew > > Changes for v2: > - fix attachment table use-after-free > - rebased on v6.17-rc1 > > Andrew Davis (3): > udmabuf: Keep track current device mappings > udmabuf: Sync buffer mappings for attached devices > udmabuf: Use module_misc_device() to register this device > > drivers/dma-buf/udmabuf.c | 133 +++++++++++++++++++------------------- > 1 file changed, 67 insertions(+), 66 deletions(-) >