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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A9869C001DD for ; Thu, 29 Jun 2023 20:51:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232242AbjF2UvD (ORCPT ); Thu, 29 Jun 2023 16:51:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45988 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232154AbjF2Uuz (ORCPT ); Thu, 29 Jun 2023 16:50:55 -0400 Received: from mail-yw1-x1149.google.com (mail-yw1-x1149.google.com [IPv6:2607:f8b0:4864:20::1149]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B3CE63593 for ; Thu, 29 Jun 2023 13:50:52 -0700 (PDT) Received: by mail-yw1-x1149.google.com with SMTP id 00721157ae682-57704aa6c69so9777987b3.0 for ; Thu, 29 Jun 2023 13:50:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1688071852; x=1690663852; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=oot+BFijmfKZ0KO/nJIrIU5HcDe1IwfMU2NYWHhWcUA=; b=dv8waobWVaNSUsOT47GOsDx8vV/iRkGODf8zThZKK4JKq0ZSnTrMWy7R3IAiX1fM4t tegdL5nlYEw74WxJbU4ciZTSnZwOVQYCywDP/6JAHDEF3YVNRNQoSLNsxO+X0jE8+WLZ 4ib0DDeM9eP9xJoybwRbj9HMMqb5rE/qTj6br4mOJWTUvJsbEgikpTHZ4BkIpODJP7uS FeOaZbb/LsG8QdVorLcYBayDjEa0cgjzLqqSuGqP5etuMwIPhztE5czIvy2CmabhCZfJ vnsHoy7ITFctcEgQKTEC1tg/xVWWYMTZvhXULy5xYz0ZzCxTiOdKZ00s3BGxSv+HUqqN HmAw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1688071852; x=1690663852; 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=oot+BFijmfKZ0KO/nJIrIU5HcDe1IwfMU2NYWHhWcUA=; b=DpeTWDGILm54Hb9yPCPIB6dzFwpAOm8gLXdsJZ4xENiKZv0QPfo7IUlvXb9W+zQHQC Q7NYphfb9R7BDa+StAtRIhQAMrxSaNYcxPhVFEIiz3aRTYuIGyZDpGDpRMAzWweB+rIF aKG4+CUmjquxBxokPvY6Xi8V+JvNuVKdFFbEHrvZ9PvyaEycgNfnoekbxD5O0N6GJ1RL L9V103faueJvfS/P+lzRUvy8ktaymqcpa9+2pc9Ei8w0Nf8cgOXYbPFxUQ6Ap0K2jcfW F+hSkOcVcrd0Lmup43S3lzCCBdUNW7nqqFN0bVbRbajlx/TjeEE7iF8QTSqtiXVkh+Ql g6vw== X-Gm-Message-State: ABy/qLbZY/Qz13O2F+B7cqnjESjvpDXq2VBa1/wKuiy8B1Eiyv614aF8 YAjFAme1exjFXSaGFKJiCZHmVmNU/fS2oDslSCwN X-Google-Smtp-Source: APBJJlG01gugR5pBeLSzgr9QaRAnN1lelWD28Wisa41iTTVqrwvQyIgcQU0WMKN/qYg/ivXFlgsOpx2irKkAZegi36c2 X-Received: from axel.svl.corp.google.com ([2620:15c:2a3:200:e20f:5917:3efa:d4bb]) (user=axelrasmussen job=sendgmr) by 2002:a25:f621:0:b0:bc7:f6af:8cff with SMTP id t33-20020a25f621000000b00bc7f6af8cffmr5650ybd.2.1688071852014; Thu, 29 Jun 2023 13:50:52 -0700 (PDT) Date: Thu, 29 Jun 2023 13:50:37 -0700 In-Reply-To: <20230629205040.665834-1-axelrasmussen@google.com> Mime-Version: 1.0 References: <20230629205040.665834-1-axelrasmussen@google.com> X-Mailer: git-send-email 2.41.0.255.g8b1d071c50-goog Message-ID: <20230629205040.665834-3-axelrasmussen@google.com> Subject: [PATCH v2 3/6] mm: userfaultfd: support UFFDIO_POISON for hugetlbfs From: Axel Rasmussen To: Alexander Viro , Andrew Morton , Christian Brauner , David Hildenbrand , Huang Ying , Hugh Dickins , James Houghton , Jiaqi Yan , Jonathan Corbet , "Liam R. Howlett" , Miaohe Lin , Mike Kravetz , "Mike Rapoport (IBM)" , Muchun Song , Nadav Amit , Naoya Horiguchi , Peter Xu , Shuah Khan , 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 Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org 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 | 33 +++++++++++++++++++++++++++++++-- mm/userfaultfd.c | 6 +----- 2 files changed, 32 insertions(+), 7 deletions(-) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 38711d49e4db..05abe88986b6 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -6090,14 +6090,24 @@ vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, } entry = huge_ptep_get(ptep); - /* PTE markers should be handled the same way as none pte */ - if (huge_pte_none_mostly(entry)) + if (huge_pte_none_mostly(entry)) { + if (is_pte_marker(entry)) { + unsigned long marker = pte_marker_get(pte_to_swp_entry(entry)); + + if (marker & PTE_MARKER_UFFD_POISON) { + ret = VM_FAULT_HWPOISON_LARGE; + goto out_mutex; + } + } /* + * Other PTE markers should be handled the same way as none PTE. + * * hugetlb_no_page will drop vma lock and hugetlb fault * mutex internally, which make us return immediately. */ return hugetlb_no_page(mm, vma, mapping, idx, address, ptep, entry, flags); + } ret = 0; @@ -6253,6 +6263,25 @@ int hugetlb_mfill_atomic_pte(pte_t *dst_pte, int writable; bool folio_in_pagecache = false; + if (uffd_flags_mode_is(flags, MFILL_ATOMIC_POISON)) { + ptl = 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 = make_pte_marker(PTE_MARKER_UFFD_POISON); + 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 = -EFAULT; folio = filemap_lock_folio(mapping, idx); diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c index 87b62ca1e09e..4436cae1c7a8 100644 --- a/mm/userfaultfd.c +++ b/mm/userfaultfd.c @@ -381,12 +381,8 @@ static __always_inline ssize_t mfill_atomic_hugetlb( * supported by hugetlb. A PMD_SIZE huge pages may exist as used * by THP. Since we can not reliably insert a zero page, this * feature is not supported. - * - * PTE marker handling for hugetlb is a bit special, so for now - * UFFDIO_POISON 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; } -- 2.41.0.255.g8b1d071c50-goog