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 CCA7A606A327 for ; Thu, 29 Oct 2026 20:40:55 +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=yRXbN0Q7; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=BizzfTpX DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Cc:To:In-Reply-To:References :Message-Id:Content-Transfer-Encoding:Content-Type:MIME-Version:Subject:Date: From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Unsubscribe-Post: List-Owner; bh=X+A4bDZDQi3RaQKtCdHq4Q8CuoDLcygQanGTwpRAvoc=; b=yRXbN0Q7nxZYui xWNizg+KzOiBk7QbxCK1GVFV75/L8aoEjC0TmlH7Za6/p8W6Gw5exO6SREEkf+wKhH8wu9AY0Ct6X OQg9sA1eyvdc0K/+RNyoTsZBw/MaICtFQX7xjxLgWvpySXzpNjh/kxRvJ4DdpS2TL6bqUadYddeEM T7AzeLjTtSdGK9iGBEdpGTNLvWu3ANgI9N87jUwabbCvrP3JG94Pmmz3VzOU7yIAQC58EwSd2nFWk ohFEUXfyVXQiEEB7GXB+3iTC9SNoQQXnUKusHbJvi2o6WipEhjBgYCijYIwQZXDUYRl49Pjpx2O+O 5Mh6e56TnZULoHpqZTIA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xMWvf-0000000ALqk-2JMx; Thu, 29 Oct 2026 20:40:55 +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 1xMWve-0000000ALqT-0RBr for kexec@lists.infradead.org; Thu, 29 Oct 2026 20:40:54 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id B040A43981; Thu, 29 Oct 2026 20:40:52 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C7BA41F01816; Thu, 29 Oct 2026 20:40:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793306452; bh=X+A4bDZDQi3RaQKtCdHq4Q8CuoDLcygQanGTwpRAvoc=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=BizzfTpXd6POIT2VXSctKqd3AYlrKo21t0yuW7k67ZzOykQkrmsF70tvdF27m6nHR yNjzirG7yxUIMePV6cd6o6LqX0pSAl/IgEUme2KHxm9O9PpZuALo6dRUKAQxGfhH+t DA4gWLZ8yol5BW+DLrHcMvUGxusQPKgKUrtfujihDYvPnJt/TJ6tSS39u2H8P+KZTy nZoUv3JERjR/gKqqgwAYI7hfD8T9nuqpmpfN6GDlxYR++om/RP/DZmQULDWoiS4s/L v9kzIakhQuG4RHlpqlhNNq5l4cyBf7BOUkPJX3p8OED7PzmsQ16EQbSRbPchOgEa/p CExcoOfTYv/tA== From: "David Hildenbrand (Arm)" Date: Thu, 29 Oct 2026 21:33:25 +0100 Subject: [PATCH v2 30/47] mm/mremap: use pudp_huge_get_and_clear() when moving huge PUDs X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20261029-fixes_core-v2-30-a64ce7f83abb@kernel.org> References: <20261029-fixes_core-v2-0-a64ce7f83abb@kernel.org> In-Reply-To: <20261029-fixes_core-v2-0-a64ce7f83abb@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, stable@vger.kernel.org, "David Hildenbrand (Arm)" X-Mailer: b4 0.16.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1293; i=david@kernel.org; h=from:subject:message-id; bh=Bwj0I+EdpwxOB+DXKGU57G1Zy0OI6QgT1Ao2qNPPN2Q=; b=owGbwMvMwCF2/OVpCdfQ3ZWMp9WSGLIer+1YqffjAfvFE1GvVCPrynaJrxGaF5yRGLK27FbyY f3NFjY8HaUsDGIcDLJiiixBwfcNXr5cV1vtxscMM4eVCWQIAxenAEzEtJDhvzePiszu11vf/Jz+ fcHuUKufNir2r8+1Gp+U2pslsLRl02qG/4lXDK3vLmCe9X8G+/cET8cdsvu85+ru1m57H2Vyc9r crywA X-Developer-Key: i=david@kernel.org; a=openpgp; fpr=1BD9CAAD735C4C3A460DFCCA4DDE10F700FF835A X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "kexec" X-Spam-Status: No, score=-18.9 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,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 move_huge_pud() reads the old PUD and clears it in separate operations. Hardware accessed or dirty updates between those operations can be lost when the saved entry is installed at the new address. The raw pud_clear() also bypasses page_table_check_pud_clear(), while set_pud_at() accounts for the destination mapping. This leaves the checker counts unbalanced for mappings tracked by page table checking. To fix it, simply use pudp_huge_get_and_clear(). Fixes: 7d846db7d0e2 ("mm/mremap: convert huge PUD move to separate helper") Cc: stable@vger.kernel.org Reviewed-by: Lorenzo Stoakes (ARM) Reviewed-by: Pedro Falcato Reviewed-by: Dev Jain Signed-off-by: David Hildenbrand (Arm) --- mm/mremap.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/mm/mremap.c b/mm/mremap.c index 0d06d7f37f19..16e736c72d9c 100644 --- a/mm/mremap.c +++ b/mm/mremap.c @@ -509,8 +509,7 @@ static bool move_huge_pud(struct pagetable_move_control *pmc, spin_lock_nested(new_ptl, SINGLE_DEPTH_NESTING); /* Clear the pud */ - pud = *old_pud; - pud_clear(old_pud); + pud = pudp_huge_get_and_clear(mm, pmc->old_addr, old_pud); VM_BUG_ON(!pud_none(*new_pud)); -- 2.43.0