From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=pass header.oldest-pass=0 smtp.remote-ip=52.101.46.14 ARC-Seal: i=2; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=pass; t=1794431726; b=lbUec4drrQWI1AuL+5fD3Rg8e4m/KV79kKEwUhDfVaS2HTqB52UpZClr54To0RJ5Bjc4 Ho6uVvf3WJH5yfAiG2t2zgI4nYTwaCmJe01ZbfEQ3ZqIJhwfJPNXrLCdMSqdcuTGQwnlP 93mTuumjFovkLpBsSRhXN+DYIzgb9FKKM69mYnLv/MK2tkcg74rjxGFgeImJ6p55WLTsn ATO8eh7SAz7YkkvfHycPu8qY2f4RwmP36MuJzDRZcdNJUI/PoJcmvg5mPZLvnCImGV4lt HIDo7wFrHYz5rc+PfsNU2I8WhcBpM4Mkc2+7AgIXV7UkdvPVFssD67jsSc64tq7QJbw== ARC-Message-Signature: i=2; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794431726; h=DMARC-Filter:DKIM-Signature:Received:Received:Date:From:To:Cc: Subject:Message-ID:References:Content-Type:Content-Disposition: In-Reply-To:X-ClientProxiedBy:MIME-Version:X-MS-PublicTrafficType: X-MS-TrafficTypeDiagnostic:X-MS-Office365-Filtering-Correlation-Id: X-MS-Exchange-SenderADCheck:X-MS-Exchange-AntiSpam-Relay: X-Microsoft-Antispam:X-Microsoft-Antispam-Message-Info: X-Forefront-Antispam-Report: X-MS-Exchange-AntiSpam-MessageData-ChunkCount: X-MS-Exchange-AntiSpam-MessageData-0:X-OriginatorOrg: X-MS-Exchange-CrossTenant-Network-Message-Id: X-MS-Exchange-CrossTenant-AuthSource:X-MS-Exchange-CrossTenant-AuthAs: X-MS-Exchange-CrossTenant-OriginalArrivalTime: X-MS-Exchange-CrossTenant-FromEntityHeader: X-MS-Exchange-CrossTenant-Id:X-MS-Exchange-CrossTenant-MailboxType: X-MS-Exchange-CrossTenant-UserPrincipalName: X-MS-Exchange-Transport-CrossTenantHeadersStamped; bh=GcuRJmfhHEBE5TyuhOQ91Uqf1/3c2UeMK9MFRYr348I=; b=xm1P5kvDZqlmvV3o38dCq70BJ+vOxjW6XPqxvmC66vLu1/E+jKXNF0Uqt9GOgdrzO/p8 Y0EOXrvPWeqRgqlLbDzpCFR8U6iMtp2uzXj6Y+gJ2Z4tte+gDxgBI1nZjxxH2odkcn8iw Vpxtw2VhmwrlQpuo93Ovh9t5HKPaXGzlw1pWzkYeiFBl5JHEeWfg3MeNrXvGmZ2XDP4/0 ILBz3f37Fw7tHcWEG/QV4JxEt15OTs9NwpaPCeWvBYXh64d8rfbjyu++09koygJ5mZYbd /hrWBEFJR1PuJRVRsDkVeiCnqeAzxbAtMCyR9A/p9L49z1JgmSSmHu6IROmJHhXPe4Q== ARC-Authentication-Results: i=2; smtp.subspace.kernel.org; dmarc=pass header.from=nvidia.com; spf=fail smtp.mailfrom=nvidia.com; dkim=pass header.d=Nvidia.com header.i=@Nvidia.com header.a=rsa-sha256 header.s=selector2 header.b=t5sK0DVe; arc=pass header.oldest-pass=0 smtp.remote-ip=52.101.46.14 Received: from CO1PR03CU002.outbound.protection.outlook.com (mail-westus2azon11010014.outbound.protection.outlook.com [52.101.46.14]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (secp384r1) server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9FDF4606A326; Wed, 11 Nov 2026 21:15:25 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 9FDF4606A326 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=nvidia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=Nvidia.com header.i=@Nvidia.com header.a=rsa-sha256 header.s=selector2 header.b=t5sK0DVe ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=xb4v1U8QRUBoCTiC8Mn9EW5tE7bo76mx2A52qbRjqjdo3lzmYQX6buNgql61KHvMiV+zmGta2iShtfcANcRE/ezUKdmkWcv9kwF/WKkmWT6N4Yg1QSioq4pZtVY45j/OTk8aTKa3f/jEsUyk9DNrT/QKf6a+zaSsjifJkWMzqPQG6iyyKyWjpH0GyLRXKpz45gLnLkshCGm/lrV7QsqRyYht+yjkZdDD3x3kLD0Swggo6jt6H5nNOKB0w+FYZ+5Pafe92i0Hy3WlQsouiq1gPEPQbzaUdFCUx6icgJWj1TxyQUYnUigx16JrMmn4pNk84oQxc/epk1u7PH9RRx206w== 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=GcuRJmfhHEBE5TyuhOQ91Uqf1/3c2UeMK9MFRYr348I=; b=Lb0FdoPTJlONtgMxUFFIx/7kCpgfqV7cnLtQJVrIznPUPVGYzohSmvghHLBLcs3vnwxDSozFMhQYyADxeAHw2mHEUfeZhyFPDOhClexFPqOh7PD4mV3w+tlTRlrziEuTs72ghKduHyHwnUFLdVVKO8PoQzZxfTc98fqorL1SjnMqAQnwvDFqtMltTFkmtmMSZiwpoBm0/UzyEhIt5OhmuRXUIspJ+NtXBlBkG9zeazgeBu9aD7aU8oOykVz8qscrg1/j6hCfOriA85HNDisNmMgBK+osZUtxMeU5V7V+HkE9UFsDrXAMqMzMyNKStWfTi5/2XS1CdSbnQ4Hh5ouGGg== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=nvidia.com; dmarc=pass action=none header.from=nvidia.com; dkim=pass header.d=nvidia.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=Nvidia.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=GcuRJmfhHEBE5TyuhOQ91Uqf1/3c2UeMK9MFRYr348I=; b=t5sK0DVeLjPXHhus3oLXADtmfSiy2LMOIzLMUieWh6a+8eogqWxsVIkNZGRL5/hGSJDHuhkIqv0xRaZRzr3TZoDtPzEO6s8I4O11X/MHVa7trYMUaWwLlvmgt4pO30IsKqkNApWTb0Og9icOeEfz/aowgcB57KYpJSiskdqKnEJ/IQg+Y6Wh1JzqgRrNHhcgvLv9Kx3uyx08iZgVaeZQJ83SVyqBzmjW0N2gJKNL425D2i5EWhiT4OpkKLaN+5QHA20L9n9KEpLRjxa+1Z21UFuqDbIriXwweHmWf9UmQgsexcD1jMvNynVU51fYcy5L3w/a8OfN4v734/MtlG3OBQ== Authentication-Results: mx.microsoft.com 1; dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nvidia.com; Received: from CH3PR12MB9730.namprd12.prod.outlook.com (2603:10b6:610:253::9) by CH3PR12MB9456.namprd12.prod.outlook.com (2603:10b6:610:1c2::11) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.615.8; Wed, 11 Nov 2026 21:15:13 +0000 Received: from CH3PR12MB9730.namprd12.prod.outlook.com ([fe80::843d:c1f0:b2ed:4128]) by CH3PR12MB9730.namprd12.prod.outlook.com ([fe80::843d:c1f0:b2ed:4128%4]) with mapi id 15.21.0615.007; Wed, 11 Nov 2026 21:15:12 +0000 Date: Thu, 12 Nov 2026 08:15:07 +1100 From: Balbir Singh To: "Lorenzo Stoakes (ARM)" Cc: David Hildenbrand , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , David Rientjes , Shakeel Butt , Andrew Morton , Jann Horn , Pedro Falcato , "Matthew Wilcox (Oracle)" , Jan Kara , Nhat Pham , Johannes Weiner , Zi Yan , Matthew Brost , Joshua Hahn , Byungchul Park , Gregory Price , Ying Huang , Alistair Popple , Usama Arif , Kairui Song , =?utf-8?B?SsOpcsO0bWU=?= Glisse , Kiryl Shutsemau , Yu-cheng Yu , Dave Hansen , Dennis Zhou , Tejun Heo , Christoph Lameter , Peng Fan , Josef Bacik , Chris Mason , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, "Borislav Petkov (AMD)" , Mark Brown , "Dennis Zhou (Facebook)" , Rick Edgecombe , stable@vger.kernel.org Subject: Re: [PATCH 10/13] mm/migrate_device: refuse to migrate shadow stacks Message-ID: References: <20261111-mason-migrate-et-al-fixes-v1-0-3d2454362e8d@kernel.org> <20261111-mason-migrate-et-al-fixes-v1-10-3d2454362e8d@kernel.org> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261111-mason-migrate-et-al-fixes-v1-10-3d2454362e8d@kernel.org> X-ClientProxiedBy: ME4P282CA0008.AUSP282.PROD.OUTLOOK.COM (2603:10c6:220:90::18) To CH3PR12MB9730.namprd12.prod.outlook.com (2603:10b6:610:253::9) X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CH3PR12MB9730:EE_|CH3PR12MB9456:EE_ X-MS-Office365-Filtering-Correlation-Id: 3f355f30-d647-46fb-f66b-08df4038dfd3 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|7416014|376014|23010399003|366016|1800799024|4143699003|11063799006|56012099006|261022075727099003|261026121527099003|261021121427099003|261102123227099003|10067099003|18002099003|22082099003; X-Microsoft-Antispam-Message-Info: Dst/5E5NTGSUMT/xrFXRrPBjBpFuFuDqZjjAagSt+6wU4PECULKrkDfeZlaTgybqhJBe+EgJxBrHCAFoDDm/6zGqi7kI2Et+bJfMxTqSpxpUrz7lYz1A8fQ4th+UX2iyb0voA5So2K7w/Y0J35YQ5qZz+md4tyaK8AXDOwqZAtKqwhKseoY/kpxF0DOOLEpXPltP5t1NBlQIsD+Szwt8tyzflOhuRrjpcZszyJVxO/8gh0Xf4LMvG2Sp8QBjJmrg5Wuq1vm2BIdQ8zT2GG8z9Sm5LeeRCaQEyLdPZwzUx50A6znywv0UMvsb7kDef8cparW0L6F2O1X65er4cXGppodfhVPZdbGzfxIuiz6JxR1UJiBgyjUNodLc0DRW45URZ7cXBvn2nc4tQ02WSb1BGlfcjLappTNrxThhrHQx9CcAaRjqoA05RiVarVy2XoLql8kco7Fbg4Oqnz3AGSgNLt2lZCceEHP6//uoSff9o9C1D5SL/7piCRfEhNx/tbnqeWrElJclmzRghOlmHDN/ETVES0f3RaJLmPwoPwoWjZR2+AgPiH34WNQmh3Qk5feW5QrIrIVYDwBthLm45dzsQUYGyweJjhp2zDQhw/5ONVJseJODctrWIWhou7M32mm9aJeDKXqwkavedStzrovpnU2fF5Snp8Zen7RWRwLcUn4= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:CH3PR12MB9730.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(7416014)(376014)(23010399003)(366016)(1800799024)(4143699003)(11063799006)(56012099006)(261022075727099003)(261026121527099003)(261021121427099003)(261102123227099003)(10067099003)(18002099003)(22082099003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?kYi+Qx08rtrDz1MDNyKLTVSPy+V08cYtHrJsZ/4pXuMKy6g4bncpSpiu3Dh1?= =?us-ascii?Q?TSHLTYLn1Fg7vwnXQeIsi5o66ZW8VgZiEYq0kyJRNk1FOqzGI9x6Q0Z/3vBf?= =?us-ascii?Q?vMvNxIyo5DcbGv3UxeTZH0rBjJOvOkAjGEWrzw5MsF/gwsnbLRAeqCdIkrpN?= =?us-ascii?Q?qwa83h5xvOkUouKlhBkBcnWL3NYkanNtnHZhWAvJ89u2A5OFli+5sdUE1D2h?= =?us-ascii?Q?sJKnuDWqTq/x4UKcjcWgbiQrxFDk+CLGF1yWUjUgHdcYnItuvfigos2hczZZ?= =?us-ascii?Q?4/F5JDJkaziXFtggf64zLcHAD5p0uWYw7puoxWLrhVtr3jHJxkFHS3Mp/PMS?= =?us-ascii?Q?l4zT8pQac3HYFonn5YpPKeeTZ4PI8tLt7VrLf3HvpGblyuao0x9fGCPWF5Nc?= =?us-ascii?Q?eOjCLpLbYFUm3pUJ4Z7PplPuEzJJSoY2yHFc9irzuhHuPDxsy0o8YUpk1zEr?= =?us-ascii?Q?buQaJDMGoZn+4vqfzw13LrBzkb+zppzJS1TsdcEjtmGdR9167P59+Ql6Ei8E?= =?us-ascii?Q?mTHzFIlcp6whcDuTKwozEd+gF+pqoG6bUapPnodg2DPu/gTLp5Q80wFxA32G?= =?us-ascii?Q?raMsTtUGLwp7eBrXE7KeSrZ/a6fpS8twTLETs55MrToed3WOR6WLkFo7rIzF?= =?us-ascii?Q?sDKWgVm/R5GvIBU9afn2TW/PACCPaA8cYc6AlVAzCu+x0exEqYuKU8dwbe1c?= =?us-ascii?Q?mdEDxxDoYH/9dN8RNg3kFIcW/EKRccdYxUZO28ZGihPiQSBWqL4/WLQRX6XT?= =?us-ascii?Q?1R0J8wE5/uk2n3/gpHgeqPiqoIz/nK9U/0EKQhlUJmWfHK8jR5OZzdyyYtwf?= =?us-ascii?Q?kvyDsdcEroPQc6P9WM/+MKOIiSM+yALZ3oqzLsSi2t1fk+f+nPD1Wu53i/0w?= =?us-ascii?Q?2FZG9SEXSoy18Of+kDnqKRMuygpTnj/XNMG/WGEEZBnKAHTJ99oMY6yY72Tj?= =?us-ascii?Q?m1dAiOsk4RjYxocvF+jclyObGYS0D531cMfn6vuw0i300d5/g3IGbIIRNpiA?= =?us-ascii?Q?TkdiguDbVTsXFKr452AgmCQ4HjIZiimE8YOnJq2RxXrnxkJUmORtiObI/MKj?= =?us-ascii?Q?Y4+Fputvzw3i3OjesYjzP3kPdO66OFkW2RhAbeWIQfT9aUxwU78WpP9ss2Uw?= =?us-ascii?Q?ywoSdJKt78bv37luZOsMqIOWSa24f6dRNz10COjqNt+EUkjeaWfsSllrm26f?= =?us-ascii?Q?3qXgTpsqjTZCSyKEzK1V0+DAWw3GKaS4IfAUV5mZGi8K1grmkF5XKm6WlHkZ?= =?us-ascii?Q?+Ll9Vy0irSG+dv2k25IfF6u0PpUfDmC3srP/0ShRLw4CFezF/q2YsVVVxoWQ?= =?us-ascii?Q?Yt4zjHKpCkuJ4+6AtLAMzOK2+JWVqGa75JEit4TNgwxhQlhKXNFwCCGmXDXq?= =?us-ascii?Q?kPg5vq4b4e5PYZdwXX+TXTvBK4MN7bisadAXlCfuVHT28CUMbGlYqhw1qyo/?= =?us-ascii?Q?sdvXz5RQ7qHgFjlkQn7d+ScNohK+Np2mI3ZNlRRhb6cYgmlL/19NHp+V8PWL?= =?us-ascii?Q?4EbMZNZcGW4Ft6+QA98A8/CNYTrBzOsQcvcqCfEzbn6i79Eg9GPdndtSfJaz?= =?us-ascii?Q?RZ1UjvcDciMiHQm4ip6BYQ+3TZpaqm/JQu7XDKgiYK6+yRfLyZPwPOz0DAYb?= =?us-ascii?Q?cvaqbFJ06Xwg7+kqGq9drrSFxBq4AN19yO51dFx/VLAbBBYq3Xddrc2YDdvN?= =?us-ascii?Q?aXTYFwS4mS99QP6j0VbvOtxs37gY8TC1MZXs/SSCi3g/aU36GyjKCcxaVCNI?= =?us-ascii?Q?C3oCsKpAUQ=3D=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 3f355f30-d647-46fb-f66b-08df4038dfd3 X-MS-Exchange-CrossTenant-AuthSource: CH3PR12MB9730.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 11 Nov 2026 21:15:12.8654 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: nBbLPHLmVHq8g7o+vvbAV+2Z0cwtJ8wuXQ7zYpe1/nZRwE4NRJRePOIRpNbGtxMYK+9eTIGlfgsh+S9zuF75dg== X-MS-Exchange-Transport-CrossTenantHeadersStamped: CH3PR12MB9456 On Wed, Nov 11, 2026 at 06:13:24PM +0000, Lorenzo Stoakes (ARM) wrote: > From: Chris Mason > > The kernel blocks ordinary writes to a shadow stack. But pte_write() is > true for a shadow stack entry, and migrate_vma_setup() sets > MIGRATE_PFN_WRITE for each page where pte_write() is true. > > Notably, the nouveau GPU driver takes that flag as permission to map its > copy of the page writable for the GPU, meaning that the next CPU access > migrates the page back into the shadow stack, and the page then holds what > the GPU wrote. > > Be consistent and disallow this for migration. > > Fixes: 54007f818206 ("mm: Introduce VM_SHADOW_STACK for shadow stack memory") > Cc: > Signed-off-by: Chris Mason > [ ljs: removed unnecessary comment, refined commit msg ] > Signed-off-by: Lorenzo Stoakes (ARM) > --- > mm/migrate_device.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/mm/migrate_device.c b/mm/migrate_device.c > index 5fe11dd01291..a59864f2e9a6 100644 > --- a/mm/migrate_device.c > +++ b/mm/migrate_device.c > @@ -759,6 +759,8 @@ int migrate_vma_setup(struct migrate_vma *args) > /* The migrate_vma page walk has no hugetlb support. */ > if (!vma_is_mm_backed(vma) || vma_is_hugetlb(vma) || vma_is_dax(vma)) > return -EINVAL; > + if (vma_test_single_mask(vma, VMA_SHADOW_STACK)) > + return -EINVAL; > if (nr_pages <= 0) > return -EINVAL; > if (args->start < vma->vm_start || args->start >= vma->vm_end) > Reviewed-by: Balbir Singh