From nobody Mon Feb 9 10:12:41 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BD9D5EB64DC for ; Thu, 6 Jul 2023 22:51:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232258AbjGFWvc (ORCPT ); Thu, 6 Jul 2023 18:51:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56798 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231962AbjGFWvP (ORCPT ); Thu, 6 Jul 2023 18:51:15 -0400 Received: from mail-yw1-x114a.google.com (mail-yw1-x114a.google.com [IPv6:2607:f8b0:4864:20::114a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 60F691FE8 for ; Thu, 6 Jul 2023 15:51:01 -0700 (PDT) Received: by mail-yw1-x114a.google.com with SMTP id 00721157ae682-56942442eb0so14211477b3.1 for ; Thu, 06 Jul 2023 15:51:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1688683860; x=1691275860; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=Qwjh0UAlAYXVze8TCXBt1h/rZKLWFE0vCD0k3jVLMVk=; b=Y2yizmMpjzL0EwPNfj1fzhhPy4fB1Fio/333NC+Pl3+CabD5WvQiBObIAnbDvfdIz0 55qqIyoV/B43yRJQMgc5PRzcnEO7oZ13pzUFcnMsRpYGZDSVSZeMWMJRv9WA6h3i6GfT TXaYPaz84vks82iZ0vbDvAGXP/Ef7g9EhKOVR1CvAJFhj45Vp0/ta+dk/HgbDOBioOwa 2BKF9RsPqJx9l5jS/r3knSsrH/fNyDrHo/fZURqQr/YXnDI5GwojI2TLVLkJxGr1ous4 fBuKAKMZ/SIafScZO/gr72YFQKtZJ6oKMnuQ1yiJQjaFtVwKCY9iv6k7Pl0tvv06AM6a 3A8g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1688683860; x=1691275860; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=Qwjh0UAlAYXVze8TCXBt1h/rZKLWFE0vCD0k3jVLMVk=; b=F1PZt3LzZsWhOcehX913UjRnrh982k6ZJiYpV5R2ePEHRkCCvrMnTfwWxtC+YFTjP4 EmOXReFP95w106KUD0hYaxGOlvjun545vYUCTEHq2qZoqnkj+ku8/eZnMEkkuz+o6sbi dF1KK83uAZPQ7rSQARsgpLJqIK4gNbEo6408mvu1cJecJXS6U+zLGQFl2SsLgBRXaFDy tMfPcez1QPA/BkYReQXCh20ZshKVA7oHXlcp+lmc/oFYEepwc9hgcEVQILtH85d/zmf0 coC1mjXDJ/NKeQbIeWkJYCo8R/jHt+HOwQN+ALhOOJk6/vSZ4pZNuW159Yq2iIXq5Jrm I+aQ== X-Gm-Message-State: ABy/qLbkX7zdVKIypukAFUVApBkRE14Ky3ElPzPJdF7CFYh0exHANV3u lkmkb71Mdsg+vjz5a4EnnuWvuOt0x92sQ7VvecfT X-Google-Smtp-Source: APBJJlEpiTBdlhXFZSaqCdtDMzVQ5W4G5GGFJKBbdNzbEaJCnt1GA18H5a/L9p5DQaoHYiuhi3h9J1K3iDtJg/4EMWJg X-Received: from axel.svl.corp.google.com ([2620:15c:2a3:200:bec3:2b1c:87a:fca2]) (user=axelrasmussen job=sendgmr) by 2002:a81:c642:0:b0:576:d9ea:1331 with SMTP id q2-20020a81c642000000b00576d9ea1331mr27910ywj.4.1688683860327; Thu, 06 Jul 2023 15:51:00 -0700 (PDT) Date: Thu, 6 Jul 2023 15:50:33 -0700 In-Reply-To: <20230706225037.1164380-1-axelrasmussen@google.com> Mime-Version: 1.0 References: <20230706225037.1164380-1-axelrasmussen@google.com> X-Mailer: git-send-email 2.41.0.255.g8b1d071c50-goog Message-ID: <20230706225037.1164380-6-axelrasmussen@google.com> Subject: [PATCH v3 5/8] mm: userfaultfd: support UFFDIO_POISON for hugetlbfs From: Axel Rasmussen To: Alexander Viro , Andrew Morton , Brian Geffon , Christian Brauner , David Hildenbrand , Gaosheng Cui , Huang Ying , Hugh Dickins , James Houghton , "Jan Alexander Steffens (heftig)" , Jiaqi Yan , Jonathan Corbet , Kefeng Wang , "Liam R. Howlett" , Miaohe Lin , Mike Kravetz , "Mike Rapoport (IBM)" , Muchun Song , Nadav Amit , Naoya Horiguchi , Peter Xu , Ryan Roberts , Shuah Khan , Suleiman Souhlal , Suren Baghdasaryan , "T.J. Alumbaugh" , Yu Zhao , ZhangPeng Cc: linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, Axel Rasmussen Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" The behavior here is the same as it is for anon/shmem. This is done separately because hugetlb pte marker handling is a bit different. Signed-off-by: Axel Rasmussen --- mm/hugetlb.c | 19 +++++++++++++++++++ mm/userfaultfd.c | 3 +-- 2 files changed, 20 insertions(+), 2 deletions(-) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 934e129d9939..20c5f6a5420a 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -6263,6 +6263,25 @@ int hugetlb_mfill_atomic_pte(pte_t *dst_pte, int writable; bool folio_in_pagecache =3D false; =20 + if (uffd_flags_mode_is(flags, MFILL_ATOMIC_POISON)) { + ptl =3D huge_pte_lock(h, dst_mm, dst_pte); + + /* Don't overwrite any existing PTEs (even markers) */ + if (!huge_pte_none(huge_ptep_get(dst_pte))) { + spin_unlock(ptl); + return -EEXIST; + } + + _dst_pte =3D make_pte_marker(PTE_MARKER_ERROR); + set_huge_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte); + + /* No need to invalidate - it was non-present before */ + update_mmu_cache(dst_vma, dst_addr, dst_pte); + + spin_unlock(ptl); + return 0; + } + if (is_continue) { ret =3D -EFAULT; folio =3D filemap_lock_folio(mapping, idx); diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c index 899aa621d7c1..9ce129fdd596 100644 --- a/mm/userfaultfd.c +++ b/mm/userfaultfd.c @@ -373,8 +373,7 @@ static __always_inline ssize_t mfill_atomic_hugetlb( * by THP. Since we can not reliably insert a zero page, this * feature is not supported. */ - if (uffd_flags_mode_is(flags, MFILL_ATOMIC_ZEROPAGE) || - uffd_flags_mode_is(flags, MFILL_ATOMIC_POISON)) { + if (uffd_flags_mode_is(flags, MFILL_ATOMIC_ZEROPAGE)) { mmap_read_unlock(dst_mm); return -EINVAL; } --=20 2.41.0.255.g8b1d071c50-goog