From nobody Fri Dec 19 11:00:30 2025 Received: from NAM11-CO1-obe.outbound.protection.outlook.com (mail-co1nam11on2059.outbound.protection.outlook.com [40.107.220.59]) (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 EE87D1B0430; Tue, 18 Feb 2025 03:56:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.220.59 ARC-Seal: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739851016; cv=fail; b=suFn/qIMlfBmR3ZROoSReP+BnKN+F6yt9FwBlXpLxQXwoFPpVYKI7P7PHpRQjxMvQGgsL2KT4s0CBHSXfaTLHOIk184Pt2h+MsfDkB4Bh24DLr9TsPiYxU6t6FKOIVQi4sDqXs3Y9Th7ep+NV8LTUjuNN4Kg0eo06TJz/NM26gM= ARC-Message-Signature: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739851016; c=relaxed/simple; bh=P/QQbn4mRCiYCkUUlrSYmHK3j3m73UFXSWrT3MHQtEI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: Content-Type:MIME-Version; b=HQyk07y6VXsK0P7vcQXk9cw9ab58hJE29S+yDIEyVEsQopLFgxnVBAWCTSIJMVwj4l5uwKDqAq4aNs85cPu+c8gRZ62AsxHB4OH8fYV4AEODTojUggfH7Hm5Ww44HAKSkHMO1j9c78uJ1FLNcOD7NuZWUj6pOcF2pJHwrK72z8Y= ARC-Authentication-Results: i=2; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com; spf=fail smtp.mailfrom=nvidia.com; dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com header.b=bUSwpuUJ; arc=fail smtp.client-ip=40.107.220.59 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) header.d=Nvidia.com header.i=@Nvidia.com header.b="bUSwpuUJ" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=NYfCw61xd+qJiKENOn3UCbhbdahW6JYJgUfKgd7HSQvmz5p84bSr1nOEqcOhh4vLXF21lsoE9x7oImsV9zdJkH+NXX6sCqJdrVcCeEy/dqno/HTZaDgvbpUzvY12CzMaELFcJ/w5/hsZG5alCIAZUOwgQuTx+XRQ5KcyS0WtzCCGv53LwTypgwjacUXdR0qp3xODG3r/dcDVzlZJdKOSxc5KBptRJLkQ37C3jlRzpOihyk82Dmgnv02nxSYmXlYGguEnIss0t8zNkqPl0LLx7SNFy96Zbg04Xzvf6DacvIGvZxOvT0Dss3QJfT6NNsFN4uBxF0LPV6IBBUFI+cEztg== 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=yNPEvAsPe8G2yTsS4zF2Ou6m25axDDKUOssAOYWV7/4=; b=wdoG7cBgBhOIepuwoB1/vgUa0X5MEKx7MUfyt+q1McduxHAVppRccBUBTXLHyWArCyUXSGksR8tw0xAJ3L9vWMADq6Wm/CCxajw6kQKqIzM1Wjk7VhVoJpFShx6xI845zRomr0wlcoFoQZHjSsbmLOGLpJteWllbvk0S6IwOkE1CnZjyyQvJXrilthe0jQ8yttklV44PQ8Z8WAkc8X3osbMdFQH1RYYfNlZgsF9ChTdbgfwsopa5YxIeuvWlkzRKLb/Lr8hrtOQXv7RYycgklZ3AmvZVDhyXvIdenig9SsqK3y3kKFrgwj8jyMhBd9Xlq13+khmvebMbk+M369uhYA== 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=yNPEvAsPe8G2yTsS4zF2Ou6m25axDDKUOssAOYWV7/4=; b=bUSwpuUJ9FXLYygKXmN3oThkkKzlOmBOmMdpk0Mel/pyys+xzcZVamMl3Ncu5axUcfn2IyWdSLHld5zb4z+6HiBQIShVGg476aXk3iE/Kq6hjIjtTV9epfdznsr3/Gn0Th4xBh1cSS5jO3THNG2cgYM2RrBnYKeto+0C1adWcjtj3W/qoFS5Pz6ag3lqdwuaJ7lEJuBUtBxP35hhgv1TzaI1syFBN3uRZJ8hvbEkwYbetee8z1PehRNW1vp0KK9VaVQLG7Yg02EjH1UKqp+tPbpFPv2N0TYyunT+Ywu071QSXoEb3rLkZGS8aTixZRi7w5sgwX3Y6AvLfeoOdwgOOQ== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nvidia.com; Received: from DS0PR12MB7726.namprd12.prod.outlook.com (2603:10b6:8:130::6) by CH3PR12MB7593.namprd12.prod.outlook.com (2603:10b6:610:141::20) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8445.19; Tue, 18 Feb 2025 03:56:52 +0000 Received: from DS0PR12MB7726.namprd12.prod.outlook.com ([fe80::953f:2f80:90c5:67fe]) by DS0PR12MB7726.namprd12.prod.outlook.com ([fe80::953f:2f80:90c5:67fe%7]) with mapi id 15.20.8445.017; Tue, 18 Feb 2025 03:56:52 +0000 From: Alistair Popple To: akpm@linux-foundation.org, dan.j.williams@intel.com, linux-mm@kvack.org Cc: Alistair Popple , Alison Schofield , lina@asahilina.net, zhang.lyra@gmail.com, gerald.schaefer@linux.ibm.com, vishal.l.verma@intel.com, dave.jiang@intel.com, logang@deltatee.com, bhelgaas@google.com, jack@suse.cz, jgg@ziepe.ca, catalin.marinas@arm.com, will@kernel.org, mpe@ellerman.id.au, npiggin@gmail.com, dave.hansen@linux.intel.com, ira.weiny@intel.com, willy@infradead.org, djwong@kernel.org, tytso@mit.edu, linmiaohe@huawei.com, david@redhat.com, peterx@redhat.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, nvdimm@lists.linux.dev, linux-cxl@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org, jhubbard@nvidia.com, hch@lst.de, david@fromorbit.com, chenhuacai@kernel.org, kernel@xen0n.name, loongarch@lists.linux.dev Subject: [PATCH v8 12/20] mm/memory: Enhance insert_page_into_pte_locked() to create writable mappings Date: Tue, 18 Feb 2025 14:55:28 +1100 Message-ID: X-Mailer: git-send-email 2.45.2 In-Reply-To: References: Content-Transfer-Encoding: quoted-printable X-ClientProxiedBy: SY5P282CA0069.AUSP282.PROD.OUTLOOK.COM (2603:10c6:10:203::13) To DS0PR12MB7726.namprd12.prod.outlook.com (2603:10b6:8:130::6) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DS0PR12MB7726:EE_|CH3PR12MB7593:EE_ X-MS-Office365-Filtering-Correlation-Id: f3bc44ad-ed74-4b5f-5dff-08dd4fd04733 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|7416014|1800799024|366016; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?rJ3ImbYysslXd9HxMj76e/txIa3I7pSrc6zoHhJlmfKu8d8PolAAq5ss8l0z?= =?us-ascii?Q?TK/GXRmKvdiqmbRwvCwIjtraZcYm2Y4lCHRpr3M3P+h9SWTGHweqwhILAxEe?= =?us-ascii?Q?EWqfMIzglJUzeedvLilgxgrwiRoicOYR509p7eg4GraIDaH7kkp9h4k5+a/8?= =?us-ascii?Q?X7SHcyUadMc5ihG9F7Y+rRctHKepvSA6/sJWYT7QH4UssTYM16neJiGahzrR?= =?us-ascii?Q?nLOUBdz/TU3lal3Cqw52m7pLIWCi5bFtb+7yHcX10HLN3pRH9TYVmkTnVcjw?= =?us-ascii?Q?32WIeS3hX7rIWpFlOyzyF37JpIxSeEUCFa0rhvoxsHncXU8x6kpm+2eqWUkx?= =?us-ascii?Q?cObJIhaLuoZmfUszYu8dc/odDDoDXK3VAgLQpWakoj6Ruuv+AK4HHFA9ZfCJ?= =?us-ascii?Q?BlLRNwbFEAUjR33tlhMxf7cuFpfpbXdsgBrSa+Ad9+lICXcIzWOxv9B3xO2G?= =?us-ascii?Q?64iU7YfCC5sz753U+fRz5NFtxLJo65KF6r8hNUF394SQj73YZgucL/eu7Ka1?= =?us-ascii?Q?szZt7cEv4kdrfxxxEL4OnqyPDOk+sGzeMPIQ0fdZzBme5zufeD+CE6JLOOyp?= =?us-ascii?Q?OZW4TjYRxQkV4NQ78KG3IU78TDrwT87suw5TvZ/WGcENgBLnQc4qbliaLBcw?= =?us-ascii?Q?Mh0Y8Goerazt30rsZA5wMO4YlbXba0p3OvQjiMnFL+YV6V2meqJ/CekaJxyc?= =?us-ascii?Q?oYkXxKHNX2R/ktjyme4EBgEppwjTLFA3WxdubCQwqq/w3a7RYqD8jP+kBoI7?= =?us-ascii?Q?rBTZmkk6uR/jhdtWG0QXnLdWZ76ilYrNo0rG47kMFgYhS7mzLbrcOJq9SUOZ?= =?us-ascii?Q?qy9UKiY34YgKJdj405pttjzJZk6wcpPKdVbazE5hU64Wn9uv8y5sjxpzKghM?= =?us-ascii?Q?6p+3ZASX/Qce4mnFlCiCnKPtP1gac32ao/vhbkcvn1GCJXik2vDfW8fp+4BR?= =?us-ascii?Q?knHnYl4jWNQpZ4Fmi2KEAndsQyV7k1k8zTj8t7c+horeiVOEwTk49+vNgj1q?= =?us-ascii?Q?Qwj8Ahk/PRI2EAv591l2wujIdIQwgUV8x4gS0EhAHDQDn8VjUJI/oSbacAOR?= =?us-ascii?Q?yf6vXxVSRBaETHx3ubU+mm8Uassi49uyBAlyY8UB7xOgsIqw54SEBttW85bw?= =?us-ascii?Q?wLNIFkTAgupCe2whTCOD4R526U/VcJ3bZS0m/Xl7wfOGrXcxPg09vtq5L3Pw?= =?us-ascii?Q?kY0mOn1tMGn78wlCaLIuCHDhEli15glm+qT5Wbx4Qr2t1ITxvXLNVtj7OvpG?= =?us-ascii?Q?s39rmyPYhZ5Wo3M20wO8LLn9igQiLPZu++0mqFYwhu5qhr5zUOEXKFboevKH?= =?us-ascii?Q?jTC0ddgD3xIQ85mNgqJSkl63VAi8GKaX/5OckmZzrOhclTk2xnVXodr7Jbif?= =?us-ascii?Q?GfKEfBvuI5R2cJIqqexR6U6S6njJ?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:DS0PR12MB7726.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(376014)(7416014)(1800799024)(366016);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?lnSzF5AfJ0Lhe1w2EWsCybFKAZZTXxqdTQkvzJioFlXKo87AFLK4B39e2NPa?= =?us-ascii?Q?wBfkK1hA4o4rcj/pjlmvkVfuKiZ6TAsDzhXza2pMBWK5gpMngufdTJ7Dj2xB?= =?us-ascii?Q?VOBDabIIYTo+trObKgqNpUUD4/DgK/SJJqpxGUAQu6Ur7t+jtWhCi11hzLGF?= =?us-ascii?Q?rxKUCB0G9ns6vKbxl4slxtGTpcgHcaEXFvWiw3wqV5oKj1FylLkw06Eoljo0?= =?us-ascii?Q?Cj1CwltRKrQFJ54gu3m5vgZLb9u8njBNv7Ja70hWw0JK7NVrSxuOz0mzQHFn?= =?us-ascii?Q?E8mrKSfb5MnkwIaz3UrpOF+ABi3cejHmljYHkHWwsS02yILgfOo5PK/Pm5jj?= =?us-ascii?Q?79Mykna1Q7UrBuc+3YjGTlM3mh2OcAE/X+1TK2jbHg5rkuInn4CN7nk7w4rE?= =?us-ascii?Q?ooCt9Lpy8Na5V96qkooTlFz96Qp9ZFxpxyLGtEn4JMSQ8D0DwtUxUEJIdd6j?= =?us-ascii?Q?+x9hmWdpRZ4+s/DBk6ncaH78az2PNGd5SH1GXm6KeXSPC6ZFmgT+L/dVdpVG?= =?us-ascii?Q?fjoeqN1ToP5yZwnQW8OFAoCJRjRZCd26TcVYaLVuaxll/IUcik7wV7qtad3f?= =?us-ascii?Q?lWjTcxj3UewvSYB8BlKmLNrggK34X/2OnUBwgUTRTEntB8uOcx9ZHZcV8Rjz?= =?us-ascii?Q?clLPCFG466P50qXIJUhDE/RE9aKe3Rwz43ifLXXocsltNkIf4lQWz+D2p5NW?= =?us-ascii?Q?rCmftZ6mRtE5v5VG23WYpj6epZoHmGxWXvAG2p0f3IsS/C/nYdirdWoPXwk1?= =?us-ascii?Q?b8UVBNujUwsPABUei5t/eoLS4i2yK/rF+EEqpmV2Y3w99caw8Rmpm6gBWdao?= =?us-ascii?Q?SE7Yc4NJ6qHIODKMVH6QmP9QxTUcE+P2rs4PjvWnr6DteopfOBUpcY9G6bg4?= =?us-ascii?Q?K/c6oFChALz1cMVsuTHN+MxYEgewD2Gc0pTcNExBcyRnR454EnLaT3kIi+/S?= =?us-ascii?Q?c4afMHc1Pq4mkq0vjpYlNSFBTmtkjaMhYXJPk4EaPQixGzPZDa9E1n3UzbSb?= =?us-ascii?Q?dBZBhah3RtZxC6EeGehHDwy5j62aPuTsawvbkJ0Wl18ZNiUfxDc8vLLMVD8u?= =?us-ascii?Q?7uTv5jZ5N1yk7xotkzadBbofUCpteJLPd0ZFeWh9+d7KcbZBdfObqY6ZajBc?= =?us-ascii?Q?a9mMSxEEsL/uljCf/0yF7t8XoWiOowzMRrjGc5fDFx/5cK88T4TW4cve0JAP?= =?us-ascii?Q?S1Swx42TnxSmm+5rQ7YXzjFsEvSvOOCf+2Up7Cv51IZy/7hNXrzFGCyKk3iG?= =?us-ascii?Q?cyIEK+GsDXzXO1XIjvYAOqFHqmrshvPuJd4j9jhriXtk6Q6+PCsDbMtJig/a?= =?us-ascii?Q?coV2eakjee/rwsT3YV1LIpPzfGxo/SK2Wv60GfmF6u6VIdHIxubBKna9TZKj?= =?us-ascii?Q?UnzaZruH5m43p6svyKNNJ6qztEpyBbfpHdFoMbzdkyWz4pd0UoYa8ZuRFgI8?= =?us-ascii?Q?8nDIhP6vo+tsfCK3yQOQ2E0Py4mzaNOyY83N3pII69YWxgpu8piKl+6PGpzC?= =?us-ascii?Q?CRxx4lVM6mD1l67Seepvhj+Tz1Hrt52tMCIp3DiQptLukzvpfW4n7+OUZRD4?= =?us-ascii?Q?DoB38vqxXXAYLHWX3pjJTmAJBmFliogcbiBmKv28?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: f3bc44ad-ed74-4b5f-5dff-08dd4fd04733 X-MS-Exchange-CrossTenant-AuthSource: DS0PR12MB7726.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 18 Feb 2025 03:56:52.6265 (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: Ql/tmcaoeAwlY1ViqPDqSRvtTGCHk0jIizKZ60Tb7KtSdTv+yko7qiRFaq2bPAww4wKbIkKz80l9e/dU0ofkSA== X-MS-Exchange-Transport-CrossTenantHeadersStamped: CH3PR12MB7593 Content-Type: text/plain; charset="utf-8" In preparation for using insert_page() for DAX, enhance insert_page_into_pte_locked() to handle establishing writable mappings. Recall that DAX returns VM_FAULT_NOPAGE after installing a PTE which bypasses the typical set_pte_range() in finish_fault. Signed-off-by: Alistair Popple Suggested-by: Dan Williams Reviewed-by: Dan Williams Acked-by: David Hildenbrand --- Changes for v7: - Drop entry and reuse pteval as suggested by David. Changes for v5: - Minor comment/formatting fixes suggested by David Hildenbrand Changes since v2: - New patch split out from "mm/memory: Add dax_insert_pfn" --- mm/memory.c | 39 ++++++++++++++++++++++++++++++--------- 1 file changed, 30 insertions(+), 9 deletions(-) diff --git a/mm/memory.c b/mm/memory.c index 905ed2f..becfaf4 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -2126,19 +2126,39 @@ static int validate_page_before_insert(struct vm_ar= ea_struct *vma, } =20 static int insert_page_into_pte_locked(struct vm_area_struct *vma, pte_t *= pte, - unsigned long addr, struct page *page, pgprot_t prot) + unsigned long addr, struct page *page, + pgprot_t prot, bool mkwrite) { struct folio *folio =3D page_folio(page); - pte_t pteval; + pte_t pteval =3D ptep_get(pte); + + if (!pte_none(pteval)) { + if (!mkwrite) + return -EBUSY; + + /* see insert_pfn(). */ + if (pte_pfn(pteval) !=3D page_to_pfn(page)) { + WARN_ON_ONCE(!is_zero_pfn(pte_pfn(pteval))); + return -EFAULT; + } + pteval =3D maybe_mkwrite(pteval, vma); + pteval =3D pte_mkyoung(pteval); + if (ptep_set_access_flags(vma, addr, pte, pteval, 1)) + update_mmu_cache(vma, addr, pte); + return 0; + } =20 - if (!pte_none(ptep_get(pte))) - return -EBUSY; /* Ok, finally just insert the thing.. */ pteval =3D mk_pte(page, prot); if (unlikely(is_zero_folio(folio))) { pteval =3D pte_mkspecial(pteval); } else { folio_get(folio); + pteval =3D mk_pte(page, prot); + if (mkwrite) { + pteval =3D pte_mkyoung(pteval); + pteval =3D maybe_mkwrite(pte_mkdirty(pteval), vma); + } inc_mm_counter(vma->vm_mm, mm_counter_file(folio)); folio_add_file_rmap_pte(folio, page, vma); } @@ -2147,7 +2167,7 @@ static int insert_page_into_pte_locked(struct vm_area= _struct *vma, pte_t *pte, } =20 static int insert_page(struct vm_area_struct *vma, unsigned long addr, - struct page *page, pgprot_t prot) + struct page *page, pgprot_t prot, bool mkwrite) { int retval; pte_t *pte; @@ -2160,7 +2180,8 @@ static int insert_page(struct vm_area_struct *vma, un= signed long addr, pte =3D get_locked_pte(vma->vm_mm, addr, &ptl); if (!pte) goto out; - retval =3D insert_page_into_pte_locked(vma, pte, addr, page, prot); + retval =3D insert_page_into_pte_locked(vma, pte, addr, page, prot, + mkwrite); pte_unmap_unlock(pte, ptl); out: return retval; @@ -2174,7 +2195,7 @@ static int insert_page_in_batch_locked(struct vm_area= _struct *vma, pte_t *pte, err =3D validate_page_before_insert(vma, page); if (err) return err; - return insert_page_into_pte_locked(vma, pte, addr, page, prot); + return insert_page_into_pte_locked(vma, pte, addr, page, prot, false); } =20 /* insert_pages() amortizes the cost of spinlock operations @@ -2310,7 +2331,7 @@ int vm_insert_page(struct vm_area_struct *vma, unsign= ed long addr, BUG_ON(vma->vm_flags & VM_PFNMAP); vm_flags_set(vma, VM_MIXEDMAP); } - return insert_page(vma, addr, page, vma->vm_page_prot); + return insert_page(vma, addr, page, vma->vm_page_prot, false); } EXPORT_SYMBOL(vm_insert_page); =20 @@ -2590,7 +2611,7 @@ static vm_fault_t __vm_insert_mixed(struct vm_area_st= ruct *vma, * result in pfn_t_has_page() =3D=3D false. */ page =3D pfn_to_page(pfn_t_to_pfn(pfn)); - err =3D insert_page(vma, addr, page, pgprot); + err =3D insert_page(vma, addr, page, pgprot, mkwrite); } else { return insert_pfn(vma, addr, pfn, pgprot, mkwrite); } --=20 git-series 0.9.1