From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 9F665C5DF8C for ; Sun, 23 Aug 2026 12:18:17 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 937956B00A3; Sun, 23 Aug 2026 08:18:16 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 90F166B00A4; Sun, 23 Aug 2026 08:18:16 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 84C336B00A5; Sun, 23 Aug 2026 08:18:16 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 61F706B00A3 for ; Sun, 23 Aug 2026 08:18:16 -0400 (EDT) Received: from smtpin23.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay01.hostedemail.com (Postfix) with ESMTP id E0E0D1C1302 for ; Sun, 23 Aug 2026 12:18:15 +0000 (UTC) X-FDA: 85132436550.23.C100598 Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf10.hostedemail.com (Postfix) with ESMTP id 32F55C000A for ; Sun, 23 Aug 2026 12:18:14 +0000 (UTC) Authentication-Results: imf10.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b="g1iX059/"; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf10.hostedemail.com: domain of rppt@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=rppt@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1787487494; 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=nPcwKjVe7nvZQyU74ZGx+OhASVw5VhjTqdhj+ioxLpo=; b=0geEVegJ6aEa7CbECCluw07e9ncMZdI/wkPkvlskTcUvGuieELnT2UDxeaKpKuJkZftuOh h4v10aqsgPRSNpWIMIx+gyL1lowHMQIeh80AQeDLe/ODqEhwMKV4GYxScYnvIwKTZ6JAWb dnmgejQor99ST9IJy1mh6/NQc0qVAaM= ARC-Authentication-Results: i=1; imf10.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b="g1iX059/"; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf10.hostedemail.com: domain of rppt@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=rppt@kernel.org ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1787487494; b=5JTo6vk2c5DQMoYAX/cf5Jj1UdfEVhlhtWsk+xdJna+xmhtupVFQdZtBUnGGYhhyO2JStZ 8zTxpfAKX/52Dbp8QemiCdxPrBvatJQf/JQmQBLBI6aKvpy1N2kg0Y9mkhtpe/N+vcLgn8 6kgAoPTYzXKItrS1HmVMQUSNPmjpRks= Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 8108F4018A; Sun, 23 Aug 2026 12:18:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C8BB31F00A3A; Sun, 23 Aug 2026 12:18:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1787487493; bh=nPcwKjVe7nvZQyU74ZGx+OhASVw5VhjTqdhj+ioxLpo=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=g1iX059/4fd671ipoP1cbd8ep4SvuMjBn2cP6Nmd1GFSZz4JBgseMsWqA3UYSw0An HQRWbf0n89PZVfi9hwgTvOF3htN9Dwr2umNmTOcziuGSoCxI6MrTZDkJonFATEkoXu bOUH7gWOBRjroBmd9mMq+HVynUNmUXmAk3TcKzFkUV5z0NK6tKfCBzg528GuJtHtm3 1XHuHpTTiAWfznjJ2OKA6uRkSHTeREfiJNjVC/jBH7YeanuaqHH+/u6L0Rw0uHETqZ kOywUx3JSn3XISIR1I+COtEeys1DRIiGtfh/TxvThI1iwPvEISDqM8MZJgZnUoDJ+y J3FXqk71iVqwQ== From: "Mike Rapoport (Microsoft)" Date: Sun, 23 Aug 2026 15:17:40 +0300 Subject: [PATCH 3/6] userfaultfd: use userfaultfd_*() helpers instead of open coded flag tests MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260823-uffd-vm-flags-v1-v1-3-3086981b33cf@kernel.org> References: <20260823-uffd-vm-flags-v1-v1-0-3086981b33cf@kernel.org> In-Reply-To: <20260823-uffd-vm-flags-v1-v1-0-3086981b33cf@kernel.org> To: Andrew Morton , David Hildenbrand Cc: Baolin Wang , Barry Song , Dev Jain , Hugh Dickins , Jann Horn , Jason Gunthorpe , John Hubbard , Jonathan Corbet , Lance Yang , "Liam R. Howlett" , Lorenzo Stoakes , Masami Hiramatsu , Mathieu Desnoyers , Mike Rapoport , Michal Hocko , Muchun Song , Nico Pache , Oscar Salvador , Pedro Falcato , Peter Xu , Ryan Roberts , Shakeel Butt , Shuah Khan , Steven Rostedt , Suren Baghdasaryan , Usama Arif , Vlastimil Babka , Zi Yan , linux-doc@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org X-Mailer: b4 0.17-dev X-Rspam-User: X-Stat-Signature: 9ys8s6syo3jmfoa7wuuzapb5cqrfycn9 X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 32F55C000A X-HE-Tag: 1787487494-538763 X-HE-Meta: U2FsdGVkX18eaCB0GTc1Cqoy/qAlt2Vp90FLs4TODlgckMnSpZPmJbLa33ZBPXOVka1WKXyj1hSBzpOe827jWhZ0Fi9cCjyMEu1LshLEwpaJDurZ2WAyX1P38gPeWDRkEBFL9Z1Nf+keEHvoO20aHYZ8QpJ/5BqXoOJS41VkJoNF2jK2MKbiC+CIdRRHuNnZocy+tUt96as+7a1j7NHsTvcjz1/xl0fW8OQJ9UQ2fnZpVPC9nCjx/Ji8V3tHDYU/atIeD3CTXFCa0Va4JfTHA2A0YpdVpr9jIg+76rrehxcZ6LKAIn6W9hV3oKrTosjQZv2Rb44LpuY/hsklagd8iCvuOrGKQMnR+tDAz/pg7BbMXFNv+ihWZSXmK4rpw6ZfI1C8NtZttr6IEP0LuZkzD7z5PqNJvwW///BHgOHuwznF5s81zwLE3+MmHVrqXuos9vHgRRVTYtQNhJaNBE/p4cO0dQbreMbnWhEObNBNoLA/WObfh3nPPTgUcIXb1boiPvwkVgAmh8Bt/CqQY/m9qJGh0DrVChH/4np5xLjD3fB317EbhqQbfiAb5OOop5lve9m3ow5pTWY/3sC8UROJcrUq8lyi3m/iTg1OPcWRPQ8wzpROKMjUVPMhG1RK76UzDQzRe2E8XiwrM4it1sjdUVfyB2J0SwJ/oGP6F8GhhPv4yOnjee7E5eUNJKdCEDQObRZ2U5XR8/8nK8pvF0Rf2Lu2jwdq+R9u0PtzSZ34mx6tdLDhYTQQseNzHSsOWkt7Es3aVnHSyLgLEx7zvnJMvTec6ZJ6NmY7IG8DfmQflPpP5I5ZQPSZn4pEaR/mRpYwSf2rHXkw1DZzDQ/uDhKPj99RMFyDaj1YA+OJmEDS7IXDHN4tEOG1h+ffzWAP1pPeS1REd7vn85deaf/owH2KCP7Icpvt3+K10ZgQ/y3zGzlartfQlmJzg/gtcUROFwU6ZQeDphzfpWcwnz5JCfJ LMhp44oF 9+SUZ1/KLHtZZ4PxlrsLB7soWfoNDrTlWHtHYUTxFPRTlWj9e8UrTKcIiBGkTO2DssR5YukOYLClqAt99DSWL/wfC7T7fNJPeMMTYGq1TpHPeVlJ+c+r6ygdueYZdtZuk34dfovNfbCLVBojAVf2onzG9082ML8PVfughcUlenSnESQobLxsZzdZWlnVS6UV9YkgaJ0mXJUhceBbwlx+Mg3AWLoBuXpTxZGpZwFwGuKOBTD4NeHRlOr4/m/7ypNllL/m3uJjgO7vd/LdZiPPKYqLySgxA2bzF7TmrweNzsxxvk2Y= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Move userfaultfd_{missing,wp,minor,rwp}() and userfaultfd_protected() ahead of uffd_disable_huge_pmd_share() and uffd_disable_fault_around() and make the latter two use the helpers rather than open coded VMA flag masks. Convert open coded VMA flag test in mfill_get_vma() to userfaultfd_wp() as well. With every user of the per-VMA uffd modes going through the helpers, their underlying representation can be changed in the next step. No functional change. Assisted-by: copilot:claude-opus-5 Signed-off-by: Mike Rapoport (Microsoft) --- include/linux/userfaultfd_k.h | 70 +++++++++++++++++++++---------------------- mm/userfaultfd.c | 2 +- 2 files changed, 35 insertions(+), 37 deletions(-) diff --git a/include/linux/userfaultfd_k.h b/include/linux/userfaultfd_k.h index 3396d270b159..d8262e3dc134 100644 --- a/include/linux/userfaultfd_k.h +++ b/include/linux/userfaultfd_k.h @@ -168,42 +168,6 @@ static inline bool is_mergeable_vm_userfaultfd_ctx(struct vm_area_struct *vma, return vma->vm_userfaultfd_ctx.ctx == vm_ctx.ctx; } -/* - * Never enable huge pmd sharing on some uffd registered vmas: - * - * - VM_UFFD_WP and VM_UFFD_RWP VMAs, because the write protect / access - * tracking information is per pgtable entry. - * - * - VM_UFFD_MINOR VMAs, because otherwise we would never get minor faults for - * VMAs which share huge pmds. (If you have two mappings to the same - * underlying pages, and fault in the non-UFFD-registered one with a write, - * with huge pmd sharing this would *also* setup the second UFFD-registered - * mapping, and we'd not get minor faults.) - */ -static inline bool uffd_disable_huge_pmd_share(struct vm_area_struct *vma) -{ - return vma_test_any_mask(vma, - mk_vma_flags_from_masks(VMA_UFFD_WP, VMA_UFFD_RWP, - VMA_UFFD_MINOR)); -} - -/* - * Don't do fault around for WP, RWP or MINOR registered uffd range. For - * MINOR registered range, fault around will be a total disaster and ptes can - * be installed without notifications; for WP it should mostly be fine as long - * as the fault around checks for pte_none() before the installation, however - * to be super safe we just forbid it; for RWP, pre-faulted neighbours would - * be indistinguishable from accessed pages in PAGEMAP_SCAN (PAGE_IS_ACCESSED) - * and pollute the tracked working set, so each page must be populated by its - * own fault. - */ -static inline bool uffd_disable_fault_around(struct vm_area_struct *vma) -{ - return vma_test_any_mask(vma, - mk_vma_flags_from_masks(VMA_UFFD_WP, VMA_UFFD_RWP, - VMA_UFFD_MINOR)); -} - static inline bool userfaultfd_missing(const struct vm_area_struct *vma) { return vma_test_any_mask(vma, VMA_UFFD_MISSING); @@ -235,6 +199,40 @@ static inline bool userfaultfd_protected(const struct vm_area_struct *vma) return userfaultfd_wp(vma) || userfaultfd_rwp(vma); } +/* + * Never enable huge pmd sharing on some uffd registered vmas: + * + * - uffd-WP and uffd-RWP VMAs, because the write protect / access tracking + * information is per pgtable entry. + * + * - uffd-MINOR VMAs, because otherwise we would never get minor faults for + * VMAs which share huge pmds. (If you have two mappings to the same + * underlying pages, and fault in the non-UFFD-registered one with a write, + * with huge pmd sharing this would *also* setup the second UFFD-registered + * mapping, and we'd not get minor faults.) + */ +static inline bool uffd_disable_huge_pmd_share(struct vm_area_struct *vma) +{ + return userfaultfd_minor(vma) || userfaultfd_wp(vma) || + userfaultfd_rwp(vma); +} + +/* + * Don't do fault around for WP, RWP or MINOR registered uffd range. For + * MINOR registered range, fault around will be a total disaster and ptes can + * be installed without notifications; for WP it should mostly be fine as long + * as the fault around checks for pte_none() before the installation, however + * to be super safe we just forbid it; for RWP, pre-faulted neighbours would + * be indistinguishable from accessed pages in PAGEMAP_SCAN (PAGE_IS_ACCESSED) + * and pollute the tracked working set, so each page must be populated by its + * own fault. + */ +static inline bool uffd_disable_fault_around(struct vm_area_struct *vma) +{ + return userfaultfd_minor(vma) || userfaultfd_wp(vma) || + userfaultfd_rwp(vma); +} + static inline bool userfaultfd_pte_wp(struct vm_area_struct *vma, pte_t pte) { diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c index 74f04c323c50..32003aa04943 100644 --- a/mm/userfaultfd.c +++ b/mm/userfaultfd.c @@ -261,7 +261,7 @@ static int mfill_get_vma(struct mfill_state *state) * validate 'mode' now that we know the dst_vma: don't allow * a wrprotect copy if the userfaultfd didn't register as WP. */ - if ((flags & MFILL_ATOMIC_WP) && !(dst_vma->vm_flags & VM_UFFD_WP)) + if ((flags & MFILL_ATOMIC_WP) && !userfaultfd_wp(dst_vma)) goto out_unlock; if (is_vm_hugetlb_page(dst_vma)) -- 2.53.0