From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 90479379ED7 for ; Sat, 17 Oct 2026 02:21:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792203697; cv=none; b=jGCwDwMjJYlN4t4KBl76Aba+PwQ6od7eKtqEHFnw6q8eoccd8yJkzhtp8yXgO76gu7cTTffdMZhmj2iMAyZrFfgV3sww7sqZGDtkPDyrEdwYGIei6jZvi1kbCWhAQ5XKF0hZOqgHOspGLlkE2WZUDu7mGfn1Xk1GZuJOaeyYDyc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792203697; c=relaxed/simple; bh=Iirutwm8PHN1O8i85EYylC0H9krUFHNc9etL6nY5yqs=; h=Date:To:From:Subject:Message-Id; b=l6zKeZzoOpDisFqKeOd0IpMe9RJSf72YzB35aL8f4a6ZgqNjbNBAfhbS+mVYFirZgPfNDQCIMcug3u+gzBso/IhPDOnMft9htXD1YFk3S58dN+0KCEfJtxC21rKdPrq0N975lTfGNg+UDdqvtbePZX5SfSmtrz4uRGRsQrUA16Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=MLYmSN2R; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="MLYmSN2R" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0D7411F000C4; Sat, 17 Oct 2026 02:21:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1792203696; bh=9PiOMUmSkVOch0aKDqpu794Jzm3OO3jn9ZudsT5tqng=; h=Date:To:From:Subject; b=MLYmSN2RNhgXpYQ3m/fKf/OXSOKj0tPWhLrXEbLBoi3R9fX/ZRjHYNxAQKtJju3De xjG3ugeNBAxhZuUc2CpVTWLjs32JjcErvZ/g+t+cq6zLRJesWZMDU3G3OuIYsU7Mq+ HQPMzMmdIJ+aK0icCs6UeKPuKPoHWehfcC9jk5Fc= Date: Fri, 16 Oct 2026 19:21:35 -0700 To: mm-commits@vger.kernel.org,vishal.l.verma@intel.com,rppt@kernel.org,ritesh.list@gmail.com,joao.m.martins@oracle.com,dave.jiang@intel.com,alison.schofield@intel.com,muchun.song@linux.dev,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-warn-on-unaligned-compound-zone-device-ranges.patch added to mm-unstable branch Message-Id: <20261017022136.0D7411F000C4@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: mm: warn on unaligned compound zone device ranges has been added to the -mm mm-unstable branch. Its filename is mm-warn-on-unaligned-compound-zone-device-ranges.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-warn-on-unaligned-compound-zone-device-ranges.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via various branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there most days ------------------------------------------------------ From: Muchun Song Subject: mm: warn on unaligned compound zone device ranges Date: Fri, 16 Oct 2026 21:13:34 +0800 A compound page of order N must start at a PFN aligned to 2^N pages. Therefore, a range used to initialize compound pages must start on a compound-page boundary and contain an integral number of compound pages. Two recent Device DAX bugs were caused by ranges that violated this invariant, but neither was detected by memmap_init_zone_device(). Warn if the adjusted zone-device range violates this invariant so future violations are reported when the compound pages are initialized. Link: https://lore.kernel.org/20261016131334.3419393-1-songmuchun@bytedance.com Link: https://lore.kernel.org/r/20261016053944.2579541-1-songmuchun@bytedance.com Link: https://lore.kernel.org/r/20261016054914.2601510-1-songmuchun@bytedance.com Signed-off-by: Muchun Song Signed-off-by: Andrew Morton Assisted-by: LLM Cc: Mike Rapoport Cc: Vishal Verma Cc: Dave Jiang Cc: Alison Schofield Cc: Joao Martins Cc: Ritesh Harjani (IBM) --- mm/mm_init.c | 2 ++ 1 file changed, 2 insertions(+) --- a/mm/mm_init.c~mm-warn-on-unaligned-compound-zone-device-ranges +++ a/mm/mm_init.c @@ -1142,6 +1142,8 @@ void __ref memmap_init_zone_device(struc if (!nr_pages) return; + VM_WARN_ON(!IS_ALIGNED(start_pfn | nr_pages, pfns_per_compound)); + /* * Seed the reusable head-page template from the first real struct * page. The normal page-init and refcount helpers must operate on _ Patches currently in -mm which might be from muchun.song@linux.dev are mm-sparse-vmemmap-drop-vmemmap_populate_dax.patch mm-sparse-vmemmap-support-device-dax-in-common-vmemmap-path.patch mm-sparse-vmemmap-drop-device-dax-specific-population-path.patch mm-sparse-vmemmap-remove-the-unused-ptpfn-argument.patch mm-sparse-vmemmap-open-code-vmemmap_populate_address.patch mm-mm_init-add-zone-mismatch-warning-during-page-init.patch mm-mm_init-add-zone-mismatch-warning-during-page-init-fix.patch mm-fix-missing-page-table-destructor-in-pagetable_free.patch arm64-mm-fix-destructor-for-unconstructed-hotplug-page-tables.patch mm-warn-on-unaligned-compound-zone-device-ranges.patch