From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 5B7A6606A31C for ; Thu, 29 Oct 2026 20:41:26 +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=Cs7/GV6p Received: by kanga.kvack.org (Postfix) id 755F36B05E2; Thu, 29 Oct 2026 16:41:25 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 72DA46B05E3; Thu, 29 Oct 2026 16:41:25 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 61D886B05E4; Thu, 29 Oct 2026 16:41:25 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 381786B05E2 for ; Thu, 29 Oct 2026 16:41:25 -0400 (EDT) Received: from smtpin13.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay02.hostedemail.com (Postfix) with ESMTP id C79DA1204DA for ; Thu, 29 Oct 2026 20:41:24 +0000 (UTC) X-FDA: 85376834088.13.2130710 Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf01.hostedemail.com (Postfix) with ESMTP id D986740005 for ; Thu, 29 Oct 2026 20:41:22 +0000 (UTC) Authentication-Results: imf01.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b="Cs7/GV6p"; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf01.hostedemail.com: domain of david@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=david@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1793306483; 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=6dCA7l8Qcb+zVMAoQ+u8vRDzaCWYfUWbDIcwuPkJnxE=; b=doOCmizswNTzfTn30NJA4YTG+8dZRR0UZtWEFpyEBYuV1g0MEPpr7VjUVj4z5cLBZvZudl IslDFXAyLRXmQlzzJ+qxd57qn7k5oHwo/ZbkjC9Zgc3fNrna0Z73+l3R/+/qL6lDfCE25s 5cZsBrlxxOcwD9DGGQ+4lOwhztlMRvc= ARC-Authentication-Results: i=1; imf01.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b="Cs7/GV6p"; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf01.hostedemail.com: domain of david@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=david@kernel.org ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1793306483; b=L4jy3G+2s5Ize0Z9sk+8LOCcEyC6GqFlSSy2B0exxwm/MpX0NnFSYxAOFXJCGSLI24/jUM 2RcHcu4mr7pBjrtCh8254VxDGMsKb8KNDfEHB2JqZmnqrJWLoah1/ecuwvn/SSXJ2dmMmL 4Q0A08PSWSe7SkooVoTUcO7WrS++50A= Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 01E7140E4D; Thu, 29 Oct 2026 20:41:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A9C4C1F01824; Thu, 29 Oct 2026 20:41:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793306481; bh=6dCA7l8Qcb+zVMAoQ+u8vRDzaCWYfUWbDIcwuPkJnxE=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=Cs7/GV6pq6eMLJFnqbR9+QKwK6ShcOEk4QCMZXclq06zJpivW8mGEnMOZW9YEUEFr me7PFVPeK46BJU1hjQNgFbL9/Ot6d2rPuJ6UQP4THorxpWzVRPECaHsgmeLmeQaRON Qz3YkhJPUWzx9FFcChAKrp6TTNfjeGiMQn3b2VQ+bZ35CbukcS1MZ9fuoJYnDyK6lG AUytHBl6JsN8niXhnFNeFcHIlaRbkFht1w9q9lGzvdPO5tqDfSobnLfmLK7CA9Um/U /nVJ+0XtYKdEenTS0MtJI5vr91YRIY3EYdRZLofvgfQHN7xXwyvcFndR9Tor8730zm oJFwe5HvlcUCg== From: "David Hildenbrand (Arm)" Date: Thu, 29 Oct 2026 21:33:27 +0100 Subject: [PATCH v2 32/47] mm/mremap: fix moving PUD leaves X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20261029-fixes_core-v2-32-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, Josef Bacik , stable@vger.kernel.org, "David Hildenbrand (Arm)" X-Mailer: b4 0.16.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2222; i=david@kernel.org; h=from:subject:message-id; bh=/15IZZT8ry+ExEMoaMWjieutil1+NN7piBMJHRZeGuI=; b=owGbwMvMwCF2/OVpCdfQ3ZWMp9WSGLIer+3odp3/SFVqszD/9KmpUY5brG9yzZ8jcP7lKREXI 8UDqbdLOkpZGMQ4GGTFFFmCgu8bvHy5rrbajY8ZZg4rE8gQBi5OAZjIG2FGhi0fIzf8PaAuzKQZ dYKBuzLwhYbeshPx4vtiqgxnXdy2z5aR4doFmTtHUgTvnzzV//uy0tLr5xwkZ8wVz4721PU8ELn WkhEA X-Developer-Key: i=david@kernel.org; a=openpgp; fpr=1BD9CAAD735C4C3A460DFCCA4DDE10F700FF835A X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: D986740005 X-Stat-Signature: fn7pw31ioj5s74hhjbgfa3ahj4a8fjcn X-Spam-Status: No, score=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_PASS, SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=4.0.1 X-Rspam-User: X-HE-Tag: 1793306482-224372 X-HE-Meta: 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 k298GRtS iyvqwaQV4K0/CDXpzr3F5tdChic7pnZ1Dxn5fchcM4Fo7MZOoSK4fG1GGOeA5Sq2yitrCS05KmahQLUgrjAEOB5KEi8oEPnKMRKw+ZK9/qrjh6eX2Il5tzJJSI8reH4+dAGdfFDwZP/DQHGJ1nQ/xmQVUwdt+Gq//mYfCjae+UKKatP4tdSlMIaR+gm9eXnrx+lRphNUWrrqAWy5fJbEPTnFHKcYepT4gKmntxOHjtAZbRTL3MAXkOLWiZdwTsLRwY4re8oAHXuIkdN1lsNDE1X6VwI7lyGpkLH2UGTo8tNnjm7X62l0i18Hr17zsoefnT4szeo14PHCqcGAM9oEu6mOiDq305kFRqGBcMV4s1fbh36adqqsIotuNB3+c+tgCP4+z Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 From: Josef Bacik pud_none_or_clear_bad() only really works on page tables. PUD leaves confuse the check and make us clear the page table entry and print a warning. Since commit aed877c2b4257 ("device/dax: properly refcount device dax pages when mapping"), this also leaks device-DAX folio references, mapcounts and RSS accounting, resulting in "Bad rss-counter state" warnings on exit. Allow PUD leaves in get_old_pud(). If a PUD leaf cannot be moved as a whole or the move fails, split it. This unmaps it with proper accounting instead of treating the leaf entry as a PMD table. Keep using pud_trans_huge() for now, in the future this code should be cleaned up to just check for PUD leaves. Fix generated by an LLM and sent by Josef Bacik in private. Fixes: a00cc7d9dd93 ("mm, x86: add support for PUD-sized transparent hugepages") Cc: stable@vger.kernel.org Signed-off-by: Josef Bacik Reviewed-by: Lorenzo Stoakes (ARM) [ david: fallthrough after splitting ] Reviewed-by: Pedro Falcato Signed-off-by: David Hildenbrand (Arm) --- mm/mremap.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/mm/mremap.c b/mm/mremap.c index 91f0865f6aee..1237718848f5 100644 --- a/mm/mremap.c +++ b/mm/mremap.c @@ -87,7 +87,7 @@ static pud_t *get_old_pud(struct mm_struct *mm, unsigned long addr) return NULL; pud = pud_offset(p4d, addr); - if (pud_none_or_clear_bad(pud)) + if (!pud_trans_huge(*pud) && pud_none_or_clear_bad(pud)) return NULL; return pud; @@ -847,11 +847,10 @@ unsigned long move_page_tables(struct pagetable_move_control *pmc) if (!new_pud) break; if (pud_trans_huge(*old_pud)) { - if (extent == HPAGE_PUD_SIZE) { - move_pgt_entry(pmc, HPAGE_PUD, old_pud, new_pud); - /* We ignore and continue on error? */ + if (extent == HPAGE_PUD_SIZE && + move_pgt_entry(pmc, HPAGE_PUD, old_pud, new_pud)) continue; - } + split_huge_pud(pmc->old, old_pud, pmc->old_addr); } else if (IS_ENABLED(CONFIG_HAVE_MOVE_PUD) && extent == PUD_SIZE) { if (move_pgt_entry(pmc, NORMAL_PUD, old_pud, new_pud)) continue; -- 2.43.0