From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B10D2606A31D for ; Tue, 27 Oct 2026 00:12:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=L+8xWqYn; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=D4IjNm97 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Reply-To:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:Date: Content-Transfer-Encoding:Content-Type:References:In-Reply-To:Cc:To:Subject: From:Message-ID:MIME-Version:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Unsubscribe-Post:List-Owner; bh=wWznlW56BSTL0Eu75Sj/9RCSS36Y1BuLcw5xAkLI7/Y=; b=L+8xWqYnoVsuQ6IwMGm0LXr4yN ym3KTGtN4Bm08Xmb8SGE4V/E8BsrdxrKFz+ciD9YtXBVEFccqy9W2y+BSc3p/KhxMpcEVF4aiGGNG Eqjb3/KkBg+sE9FdqlL8TV42hYjBbASVMxbH9Lvt4IDtDsj40UM/eXVALLaS+BJOkeWoKnLV7Broz 4YnuSzXzXNkxQ2n9OnBSA9M0lzBoJAT3OcuGR7ipkczHWLI+Oonz2c6FQwCIiSp3KfqSsgVXVSSBH sTvwUabSSgfp7hG8XLG8uOkEqV4UCBbR2ycOR1zFib8bbzpGVCt/Lwd5bTpW+72onAB6JF03pW5wb xq30F8Jw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xLUo2-00000003V34-1iAp; Tue, 27 Oct 2026 00:12:46 +0000 Received: from sea.source.kernel.org ([172.234.252.31]) by bombadil.infradead.org with esmtps (Exim 4.100.1 #2 (Red Hat Linux)) id 1xLUo1-00000003V20-0W0k for kexec@lists.infradead.org; Tue, 27 Oct 2026 00:12:45 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id CA5AD40141; Tue, 27 Oct 2026 00:12:44 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 79FBB1F01828; Tue, 27 Oct 2026 00:12:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793059964; bh=wWznlW56BSTL0Eu75Sj/9RCSS36Y1BuLcw5xAkLI7/Y=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=D4IjNm97WtwDr9dvhiqRb5JZ5ExQ+p+VQaFRUAeFCLX99FvNhZ6AuwwiXBJm4UM55 xZiVqpvSuvPbnFci/YcL7xGU0UNTENFaR/PjGjFsjE2TW6bg7iJJFgdACyeo3VTEiU FjAgs2RxOqLU37aQiDkPEtqi8ZfZQPybf2CXkGnWMeoQTGC4k1zfqg2KdNFypUo4Ik IeTdYnOS1J/4rSGGz2dzEnPZE/JXHS+MvYjlW7CzsszbQRbAhMg/ITZrdNuN8RbaJw T29XgGJhioFw/BimC/o0Jm+LEnO0C30HCp93CHM3w4xsjE0j1zqyJnuHObxN0Rskjo ChD8j/WqsBzXg== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH 13/46] mm/huge_memory: fix truncate racing with PMD zapping To: =?utf-8?b?RGF2aWQgSGlsZGVuYnJhbmQgKEFybSk=?= , "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" , =?utf-8?b?TWF0dGhldyBXaWxjb3ggKE9yYWNsZSk=?= , "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: kexec@lists.infradead.org, "Chris Mason" In-Reply-To: <20261027-fixes_core-v1-13-6f74bec9a5bb@kernel.org> References: <20261027-fixes_core-v1-0-6f74bec9a5bb@kernel.org> <20261027-fixes_core-v1-13-6f74bec9a5bb@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Tue, 27 Oct 2026 00:12:41 +0000 X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: sashiko-reviews@lists.linux.dev Sender: "kexec" X-Spam-Status: No, score=-11.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 X-Archived-By: > From: Chris Mason >=20 > zap_huge_pmd_folio() removes the rmap before calling folio_mark_dirty(). > If this was the last mapping, truncation can skip unmapping the folio > and proceed without waiting for the PMD lock, racing with dirtying. >=20 > ifs_set_range_dirty() can oops if MADV_DONTNEED races with > ftruncate() on XFS, when we get the folio set dirty after it was found > to not be mapped anymore. >=20 > Move folio_mark_dirty() and folio_mark_accessed() before rmap removal, > matching the PTE zap path. This keeps the folio mapped while updating > its state, so truncation must wait for the page table lock. >=20 > Fix generated by an LLM and sent by Chris Mason in private. >=20 > Fixes: fe6cf984939d ("mm/huge_memory: transfer the pmd dirty bit to the f= olio on zap") > Cc: stable@vger.kernel.org > Signed-off-by: Chris Mason > [ david: simplify comment and description ] > Signed-off-by: David Hildenbrand (Arm) Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261027-fixes_core= -v1-0-6f74bec9a5bb@kernel.org?part=3D13