From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794046842; b=LaEIR6DqSru0jZvN/dqe/AXwnG3J70y+MD1V0dLWUEVMgj1DeGJOU/uLZqpcdh2igx5Y sMR9T8F33AvSj/TAKEYJFELyy39N3cbhIlsk4r8agomXdHHVLhDjAfhd854H6YItnb9m3 pBM1g77K3zOg+CCVE0uKs3zRn1TOXiQ49jWKJZtDB7rnNWdZ9sFNt8e2QyIPAASWMjAia /QWKtAyg+GIVl/KXPgY8kA5Pk6E4QznuqRP06nfLeWN/z0UiU6A4JW2y7VnULvpITqMNs 1KCsMWMC3dYVDsC/faqkJ421xIX+F+JW/p2wKNhf5cquc9QZJWEfehWeWjpqa43e6+Q== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794046842; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=tu/e7EFbVaxsA9hD9MG9gnoqB0lS/QInDuf/3PyQpBE=; b=1zxPOO7dPV69zmcHAGpit3uN5xwq+OkfvwqJzybXc2E2VXP7ABO38ahncrAHrgtVDaSs KbM8RafmG+7yXW0oqJt6AgagyK1JiJIa26kiIsknN4ImAkTeXZpF18Vnkz/VfachpPKaY 0bQB+Vv6nUChsCTtf3pGQgObfa2KfH6oIep80IYZeGwGFP1syPhr2CNRLSOaMO6htYTR4 UJm5k6SWphSAitwoyGD8myzgPKJFgBJyIwUP8QqKSJhcm31DGbd08PlNa+8AmnwEu0mX0 6qGGgyf1fCZwCCgkWH3FLXmjowaqzoZDV56UfPwypbZAmVie7Blu9HlIGW7x+3yZTGw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=GA3gnIQH; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 14072606A334 for ; Sat, 7 Nov 2026 10:20:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=GA3gnIQH Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6C16F1F008A1; Sat, 7 Nov 2026 10:20:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794046841; bh=tu/e7EFbVaxsA9hD9MG9gnoqB0lS/QInDuf/3PyQpBE=; h=From:To:Cc:Subject:Date; b=GA3gnIQHAjrpMUjUgizvNZLy/m4uWXZsDngw5MOsXdd8ibkhvCp2dNSlOoKd10joE e4i1uy6XudnXsh9eDUAnRVAhIPFIkuZpP3PiF7pW2xShXcy9cgI3RzjdNCzft4IqLw c6Ty7h7dOzIpk0JSjFAZiiC8tn4f/jOrL7KVV0h5/LWt+n4TF6sxUV2t5NVlOruOjG 1GqsCi3K8Wi5ncugjNsrwUaV5ClkVnQoUiYpMGYxRyG/pB8xraBehF7UQrtu3TdrIH tOGxcwpxhVRZWYOLE9sWqXDo5jXBf16qaqrl48cb5Lb2b3kTz6gONmhSSjtpAzY1xx /GFxOXpXE10Ig== From: Sasha Levin To: gourry@gourry.net, akpm@linux-foundation.org, sashiko-bot@kernel.org, ljs@kernel.org, david@kernel.org, ziy@nvidia.com, liam@infradead.org, vbabka@kernel.org, jannh@google.com, joshua.hahnjy@gmail.com, rakie.kim@sk.com, ying.huang@linux.alibaba.com, peterx@redhat.com, jgg@ziepe.ca Cc: stable@vger.kernel.org Subject: FAILED: patch "[PATCH] mm/madvise: use vm_normal_folio_pmd() in cold/pageout PMD range" failed to apply to 6.12-stable tree Date: Sat, 7 Nov 2026 05:20:39 -0500 Message-ID: <20261107052039-failed-6.12-0bd719cb607e@kernel.org> X-Mailer: git-send-email 2.53.0 X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.12-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.12.y git checkout FETCH_HEAD git cherry-pick -x 0bd719cb607ef14bcd554e044bbd80dd901b9996 # git commit -s git send-email --to '' --in-reply-to '20261107052039-failed-6.12-0bd719cb607e@kernel.org' --subject-prefix 'PATCH 6.12.y' 'HEAD^..' Thanks, Sasha ------------------ original commit in Linus's tree ------------------ >From 0bd719cb607ef14bcd554e044bbd80dd901b9996 Mon Sep 17 00:00:00 2001 From: Gregory Price Date: Sat, 26 Sep 2026 06:51:10 -0400 Subject: [PATCH] mm/madvise: use vm_normal_folio_pmd() in cold/pageout PMD range 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. Link: https://lore.kernel.org/20260926105110.2156652-3-gourry@gourry.net Fixes: 3c8e44c9b369 ("mm: mark special bits for huge pfn mappings when inject") Signed-off-by: Gregory Price (Meta) Signed-off-by: Andrew Morton Reported-by: sashiko-bot Closes: https://sashiko.dev/#/patchset/20260817220810.1175596-1-gourry%40gourry.net Reviewed-by: Lorenzo Stoakes (ARM) Acked-by: David Hildenbrand (Arm) Reviewed-by: Zi Yan Assisted-by: LLM Cc: Liam R. Howlett Cc: Vlastimil Babka Cc: Jann Horn Cc: Joshua Hahn Cc: Rakie Kim Cc: Ying Huang Cc: Peter Xu Cc: Jason Gunthorpe Cc: # v6.19+ --- mm/madvise.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/mm/madvise.c b/mm/madvise.c index 963337f93a7a1..6c52f699222b2 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -394,16 +394,15 @@ static int madvise_cold_or_pageout_pte_range(pmd_t *pmd, return 0; orig_pmd = *pmd; - if (is_huge_zero_pmd(orig_pmd)) - goto huge_unlock; - if (unlikely(!pmd_present(orig_pmd))) { VM_WARN_ON_ONCE(!pmd_is_migration_entry(orig_pmd) && !pmd_is_device_private_entry(orig_pmd)); goto huge_unlock; } - folio = pmd_folio(orig_pmd); + folio = vm_normal_folio_pmd(vma, addr, orig_pmd); + if (!folio) + goto huge_unlock; if (folio_is_zone_device(folio)) goto huge_unlock; -- 2.53.0