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=1793056938; b=hLIt9rfSSZDqH4CChK4GLCW6dHGE3596oGoOpCFXB1SU4PEDQVTbPkXebT4yjxOL1VaX QQ9XLdPRZ5+zAz8eSVKbvU7airzfa9mjTVb16JklOCvGcdEL0Wl2b+T8ItwOkARLeqhcl mZ0zRPD8VWq7Pu29gHKPMhGWZHBgRzuEWTzMiiqJCSXPduIZM+iunj6Jh7ZtIfh7exMHU 5BmXjHf++fXHwkSw9B8O1ndPIptp40SL4LSDpyvR+8xtA+/IPy/wHWOag9sB8bb1Y0KBY iKP5HAUoeew68hacsqmPK/q2ZxMgV2iru9t1HwUVdRM14HjHjohDmfudaZjF+NJ5YGg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793056938; h=Received:DKIM-Signature:From:Date:Subject:MIME-Version:Content-Type: Content-Transfer-Encoding:Message-Id:References:In-Reply-To:To:Cc: X-Mailer:X-Developer-Signature:X-Developer-Key; bh=ord/cNP4CRsRT4Xvi9c7rgpbK1vGRFp0LVhUmuKhqjI=; b=g/Aw8ofccEcGa+ruI9FSRhZt+mYzAkp0cqTbgImRqGqYsekXdTIorDupeianIN6aK8g7 tSiHauvuPVaWOPQ6/wTCweAcwObX3ZhbN3HemFyKEoQvkaiLAVh2FedlSsjkR8Xf4pb35 41ejMaq7YXCwJXek4UITXt9DbIaOfr/cIXJF/HcXgAyPbhk1QuTlod2JogstOtgR8dJ1J Uu1C+Sy3mYu6wc4ETjUF8fstSH7fv6/5oS1xq9eJ4FNv0dOLzN3mmZMtYAYBIVEXY3V8W vDbkcP0wpMbnbmhCVIeXOExUkRDRInI7/jK0DbLgYOjYZ3Ydvzmg/B+H5JUqq4XnUfA== 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="A/EO6/mr"; 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 AB9B7606A31B; Mon, 26 Oct 2026 23:22:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=A/EO6/mr Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2B94E1F01825; Mon, 26 Oct 2026 23:21:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793056937; bh=ord/cNP4CRsRT4Xvi9c7rgpbK1vGRFp0LVhUmuKhqjI=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=A/EO6/mrzkD/mg3LADo0kMno6NcudvbnDZM8+tP9DZDoU8h9co0wU4clyW6YZLGFl ez77QV1LIY6IfUQBxzaqwM2+Y8X4xFpLbUPyaBW70KMfkz7RLbSPEpjilPcUHcVlaz Nc9VIAX3oxSv0TtODqmK33x8Gw+Djny92ATTXKcaqlSN630jZjUPuTr//5PNs6+tUj Bv42ssVm1ha1+CGtMl3ZCTjR1Vr36giZAnOD4Sa1XOnawJ5sMZ9PD0aJQeKTO0fxuS lWZTZeTL6k/4c+Sx5wtd160zyY8s+XW3ZtFGyroIsKFMK3n51Km+Sv+lIi+J0jrgRR 77f61FFUxGTOQ== From: "David Hildenbrand (Arm)" Date: Tue, 27 Oct 2026 00:17:34 +0100 Subject: [PATCH 14/46] mm/huge_memory: fix zapping migration entries for device-private THPs 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 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20261027-fixes_core-v1-14-6f74bec9a5bb@kernel.org> References: <20261027-fixes_core-v1-0-6f74bec9a5bb@kernel.org> In-Reply-To: <20261027-fixes_core-v1-0-6f74bec9a5bb@kernel.org> To: Andrew Morton , Johannes Weiner , Michal Hocko , Qi Zheng , Shakeel Butt , Lorenzo Stoakes , Kairui Song , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Baoquan He , Baolin Wang , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Kees Cook , Peter Zijlstra , Jann Horn , Pedro Falcato , Hugh Dickins , Pasha Tatashin , Pratyush Yadav , "Matthew Wilcox (Oracle)" , Jan Kara , Zi Yan , Lance Yang , Rik van Riel , Harry Yoo , Alistair Popple , Nico Pache , Ryan Roberts , Dev Jain , Usama Arif , Kiryl Shutsemau , Matthew Brost , John Hubbard , Peter Xu , Will Deacon , "Aneesh Kumar K.V" , Nick Piggin , Oscar Salvador , Minchan Kim , Muchun Song , Xu Xin , Chengming Zhou , Chris Li , Kemeng Shi , Nhat Pham , Youngjun Park , Gregory Price , Joshua Hahn , Rakie Kim , Ying Huang , Jason Gunthorpe Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, kexec@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-cxl@vger.kernel.org, Chris Mason , stable@vger.kernel.org, "David Hildenbrand (Arm)" X-Mailer: b4 0.16.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1559; i=david@kernel.org; h=from:subject:message-id; bh=0T8y59LcTWa+97MvrqvLjbP/3maGmTKua0tBD9F4/0I=; b=owGbwMvMwCF2/OVpCdfQ3ZWMp9WSGLLu35+ia/cvPpk1zX/O+d5dB20O/XTZps6+dGX6/C/Wn 32/e/6/1FHKwiDGwSArpsgSFHzf4OXLdbXVbnzMMHNYmUCGMHBxCsBEdq5m+J++r4l1Vdemiaxr 97IsOrB126Hm5Fs1z7zO++7NmFr9v2YlI8MSV+slVydHMX/KX/44/mLh7Gc8sTxTlc/N5lTMr6r ZxMMDAA== X-Developer-Key: i=david@kernel.org; a=openpgp; fpr=1BD9CAAD735C4C3A460DFCCA4DDE10F700FF835A From: Chris Mason A PMD migration entry can refer to a device-private folio. zap_huge_pmd_folio() checks the folio type instead of the entry type, so it treats such a migration entry as a device-private entry. Installing the migration entry already removed the reverse mapping and dropped the mapping reference. Zapping it must not repeat those operations. Concurrent MADV_DONTNEED during migration back to system memory can trigger this. Check the PMD entry type using pmd_is_device_private_entry(). Fix generated by an LLM and sent by Chris Mason in private. Fixes: 368076f52ebe ("mm/huge_memory: add device-private THP support to PMD operations") Cc: stable@vger.kernel.org Signed-off-by: Chris Mason [ david: simplify description ] Signed-off-by: David Hildenbrand (Arm) --- mm/huge_memory.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index eda020dd6e33f..1b50cc2b35351 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2493,7 +2493,7 @@ static inline void zap_deposited_table(struct mm_struct *mm, pmd_t *pmd) static void zap_huge_pmd_folio(struct mm_struct *mm, struct vm_area_struct *vma, pmd_t pmdval, struct folio *folio, bool is_present) { - const bool is_device_private = folio_is_device_private(folio); + const bool is_device_private = !is_present && pmd_is_device_private_entry(pmdval); /* Transfer young+dirty while the folio is still mapped. */ if (is_present && !folio_test_anon(folio)) { -- 2.43.0