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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 161D8C88E5C for ; Wed, 16 Sep 2026 07:26:15 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id CBE576B0096; Wed, 16 Sep 2026 03:26:14 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C57216B0098; Wed, 16 Sep 2026 03:26:14 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id AF79D6B0099; Wed, 16 Sep 2026 03:26:14 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 7DED76B0096 for ; Wed, 16 Sep 2026 03:26:14 -0400 (EDT) Received: from smtpin10.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 0C772A5C44 for ; Wed, 16 Sep 2026 07:26:14 +0000 (UTC) X-FDA: 85218791868.10.068038E Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf15.hostedemail.com (Postfix) with ESMTP id 3FC43A0007 for ; Wed, 16 Sep 2026 07:26:12 +0000 (UTC) Authentication-Results: imf15.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=oJMnzF5C; spf=pass (imf15.hostedemail.com: domain of david@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=david@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1789543572; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=uiduZlpOSzqWe+j41tpJG7GtdSaFaqUdX9h65p2QPhU=; b=13bZ87BV2dnSfqjitFPA6XLTBqDqS48qyL25KRYdxf7vckTQNrxrbIQ3Fi5M4zj2shZ1d+ YQWTrn6RDQw4SR6ZJZm9fqcT6jTAvU0KC+kbja5nj3ZUKZAiCJlb0xCcNCpVKEIeDCsK9L AD5/U1+O/HoWf5njI4oVKy7O5HSBex4= ARC-Authentication-Results: i=1; imf15.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=oJMnzF5C; spf=pass (imf15.hostedemail.com: domain of david@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=david@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1789543572; b=qfQWLoHBlHmKQeTHUt2gajC57Sj7rsyuMhJVwSMnRqe0KkWHAcjtCVGwTKMLcP9/w3voHx J5DF9s+R7vxMAH4gigWW8lzwy4gMe2NCGdRyz9EtzvYvohgfkiNG/dUahc2S6uEHdRZSjm rkiknOEDfcciHjKhgyy6c5XD+os9dNk= Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 7F99943A22; Wed, 16 Sep 2026 07:26:11 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AF07B1F00893; Wed, 16 Sep 2026 07:26:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789543571; bh=uiduZlpOSzqWe+j41tpJG7GtdSaFaqUdX9h65p2QPhU=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=oJMnzF5C7Ev3Dp3N/bV4RJunca3jlNa4TqP6Tj6wD/sqhaf1CRL+n1udXp+dqT4WV eFwQbg8CoIfWO2+GGOfrhngEwutzN69U/TRLUtq6rcLi3SUIlNtU8ZF5YdjTw7ZOob vs7u+mjt807w0erMTUVqxlTY1i1HBswBBh+r0uYT85FpfeFcw3ZdYCFC3vOptMKJaM jlW6tBfOeNLhMb7tU38QVTUhvk4NTCc10iK13orqu2ElcuJ5XW2RGAaMfiG7Ln0yHG ocTNsYde7HHddUhAp2JRBNVWCLB+xGV1aMmukXbGwcBogIQzk/XLcwYOP3uvMGHkhC mreQEkfBjRSkA== Message-ID: <4efdbc78-308f-46cd-ba3d-ae59b53c7ee2@kernel.org> Date: Wed, 16 Sep 2026 09:26:05 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 2/2] mm/madvise: use vm_normal_folio_pmd() in cold/pageout PMD range To: Gregory Price , linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, kernel-team@meta.com, akpm@linux-foundation.org, liam@infradead.org, ljs@kernel.org, vbabka@kernel.org, jannh@google.com, ziy@nvidia.com, matthew.brost@intel.com, joshua.hahnjy@gmail.com, rakie.kim@sk.com, byungchul@sk.com, ying.huang@linux.alibaba.com, apopple@nvidia.com, peterx@redhat.com, jgg@ziepe.ca, sashiko-bot , stable@vger.kernel.org References: <20260912034833.2952750-1-gourry@gourry.net> <20260912034833.2952750-3-gourry@gourry.net> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzS5EYXZpZCBIaWxk ZW5icmFuZCAoQ3VycmVudCkgPGRhdmlkQGtlcm5lbC5vcmc+wsGQBBMBCAA6AhsDBQkmWAik AgsJBBUKCQgCFgICHgUCF4AWIQQb2cqtc1xMOkYN/MpN3hD3AP+DWgUCaYJt/AIZAQAKCRBN 3hD3AP+DWriiD/9BLGEKG+N8L2AXhikJg6YmXom9ytRwPqDgpHpVg2xdhopoWdMRXjzOrIKD g4LSnFaKneQD0hZhoArEeamG5tyo32xoRsPwkbpIzL0OKSZ8G6mVbFGpjmyDLQCAxteXCLXz ZI0VbsuJKelYnKcXWOIndOrNRvE5eoOfTt2XfBnAapxMYY2IsV+qaUXlO63GgfIOg8RBaj7x 3NxkI3rV0SHhI4GU9K6jCvGghxeS1QX6L/XI9mfAYaIwGy5B68kF26piAVYv/QZDEVIpo3t7 /fjSpxKT8plJH6rhhR0epy8dWRHk3qT5tk2P85twasdloWtkMZ7FsCJRKWscm1BLpsDn6EQ4 jeMHECiY9kGKKi8dQpv3FRyo2QApZ49NNDbwcR0ZndK0XFo15iH708H5Qja/8TuXCwnPWAcJ DQoNIDFyaxe26Rx3ZwUkRALa3iPcVjE0//TrQ4KnFf+lMBSrS33xDDBfevW9+Dk6IISmDH1R HFq2jpkN+FX/PE8eVhV68B2DsAPZ5rUwyCKUXPTJ/irrCCmAAb5Jpv11S7hUSpqtM/6oVESC 3z/7CzrVtRODzLtNgV4r5EI+wAv/3PgJLlMwgJM90Fb3CB2IgbxhjvmB1WNdvXACVydx55V7 LPPKodSTF29rlnQAf9HLgCphuuSrrPn5VQDaYZl4N/7zc2wcWM7BTQRVy5+RARAA59fefSDR 9nMGCb9LbMX+TFAoIQo/wgP5XPyzLYakO+94GrgfZjfhdaxPXMsl2+o8jhp/hlIzG56taNdt VZtPp3ih1AgbR8rHgXw1xwOpuAd5lE1qNd54ndHuADO9a9A0vPimIes78Hi1/yy+ZEEvRkHk /kDa6F3AtTc1m4rbbOk2fiKzzsE9YXweFjQvl9p+AMw6qd/iC4lUk9g0+FQXNdRs+o4o6Qvy iOQJfGQ4UcBuOy1IrkJrd8qq5jet1fcM2j4QvsW8CLDWZS1L7kZ5gT5EycMKxUWb8LuRjxzZ 3QY1aQH2kkzn6acigU3HLtgFyV1gBNV44ehjgvJpRY2cC8VhanTx0dZ9mj1YKIky5N+C0f21 zvntBqcxV0+3p8MrxRRcgEtDZNav+xAoT3G0W4SahAaUTWXpsZoOecwtxi74CyneQNPTDjNg azHmvpdBVEfj7k3p4dmJp5i0U66Onmf6mMFpArvBRSMOKU9DlAzMi4IvhiNWjKVaIE2Se9BY FdKVAJaZq85P2y20ZBd08ILnKcj7XKZkLU5FkoA0udEBvQ0f9QLNyyy3DZMCQWcwRuj1m73D sq8DEFBdZ5eEkj1dCyx+t/ga6x2rHyc8Sl86oK1tvAkwBNsfKou3v+jP/l14a7DGBvrmlYjO 59o3t6inu6H7pt7OL6u6BQj7DoMAEQEAAcLBfAQYAQgAJgIbDBYhBBvZyq1zXEw6Rg38yk3e EPcA/4NaBQJonNqrBQkmWAihAAoJEE3eEPcA/4NaKtMQALAJ8PzprBEXbXcEXwDKQu+P/vts IfUb1UNMfMV76BicGa5NCZnJNQASDP/+bFg6O3gx5NbhHHPeaWz/VxlOmYHokHodOvtL0WCC 8A5PEP8tOk6029Z+J+xUcMrJClNVFpzVvOpb1lCbhjwAV465Hy+NUSbbUiRxdzNQtLtgZzOV Zw7jxUCs4UUZLQTCuBpFgb15bBxYZ/BL9MbzxPxvfUQIPbnzQMcqtpUs21CMK2PdfCh5c4gS sDci6D5/ZIBw94UQWmGpM/O1ilGXde2ZzzGYl64glmccD8e87OnEgKnH3FbnJnT4iJchtSvx yJNi1+t0+qDti4m88+/9IuPqCKb6Stl+s2dnLtJNrjXBGJtsQG/sRpqsJz5x1/2nPJSRMsx9 5YfqbdrJSOFXDzZ8/r82HgQEtUvlSXNaXCa95ez0UkOG7+bDm2b3s0XahBQeLVCH0mw3RAQg r7xDAYKIrAwfHHmMTnBQDPJwVqxJjVNr7yBic4yfzVWGCGNE4DnOW0vcIeoyhy9vnIa3w1uZ 3iyY2Nsd7JxfKu1PRhCGwXzRw5TlfEsoRI7V9A8isUCoqE2Dzh3FvYHVeX4Us+bRL/oqareJ CIFqgYMyvHj7Q06kTKmauOe4Nf0l0qEkIuIzfoLJ3qr5UyXc2hLtWyT9Ir+lYlX9efqh7mOY qIws/H2t In-Reply-To: <20260912034833.2952750-3-gourry@gourry.net> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspam-User: X-Stat-Signature: o9fqz6w953nney9ejruo65w39kxxpgw5 X-Rspamd-Queue-Id: 3FC43A0007 X-Rspamd-Server: rspam07 X-HE-Tag: 1789543572-230734 X-HE-Meta: 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 +HFQmsBO 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 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 9/12/26 05:48, Gregory Price wrote: > mmap a VM_MIXEDMAP region whose ->huge_fault installs a PMD through > vmf_insert_pfn_pmd() - mshv_vtl_low does this, and needs CAP_SYS_ADMIN > to open - then: > > madvise(p, PMD_SIZE, MADV_PAGEOUT); > > With a stand-in module for the driver: > > BUG: unable to handle page fault for address: fffff587c0000008 > RIP: 0010:madvise_cold_or_pageout_pte_range+0x410/0x9b0 > walk_pgd_range+0x52b/0xaf0 > __walk_page_range+0x6a/0x1d0 > walk_page_range_vma_unsafe+0x8e/0x120 > madvise_pageout+0xb2/0x180 > madvise_vma_behavior+0x46b/0xa90 > do_madvise+0x108/0x190 > __x64_sys_madvise+0x26/0x30 > > Nothing validates the pfn on the way in: > > can_madv_lru_vma() rejects VM_PFNMAP, but not VM_MIXEDMAP > can_fault() *pfn = vmf->pgoff & ~(mask >> PAGE_SHIFT); > vmf_insert_pfn_pmd() no pfn_valid() check > pmd_folio() pfn_to_page() -> unpopulated vmemmap > > Even with a valid pfn the path is wrong. The mapping carries no rmap, so > folio_maybe_mapped_shared() sees mapcount 0, and the walker goes on to > folio_deactivate(), or folio_isolate_lru() plus reclaim_pages(), against a > folio this mapping does not own. > > Use vm_normal_folio_pmd() and skip on NULL, as the PTE half of this same > walker already does with vm_normal_folio(). This also filters the huge > zero PMD, so its separate check is no longer needed. > > Fixes: 3c8e44c9b369 ("mm: mark special bits for huge pfn mappings when inject") > Reported-by: sashiko-bot > Closes: https://sashiko.dev/#/patchset/20260817220810.1175596-1-gourry%40gourry.net > Cc: stable@vger.kernel.org # v6.19+ > Assisted-by: LLM > Signed-off-by: Gregory Price (Meta) > --- Acked-by: David Hildenbrand (Arm) -- Cheers, David