From: Peter Xu <peterx@redhat.com>
To: linux-mm@kvack.org, linux-kernel@vger.kernel.org
Cc: Rik van Riel <riel@surriel.com>,
Muchun Song <songmuchun@bytedance.com>,
Andrew Morton <akpm@linux-foundation.org>,
peterx@redhat.com, James Houghton <jthoughton@google.com>,
Nadav Amit <nadav.amit@gmail.com>,
Andrea Arcangeli <aarcange@redhat.com>,
David Hildenbrand <david@redhat.com>,
Miaohe Lin <linmiaohe@huawei.com>,
Mike Kravetz <mike.kravetz@oracle.com>
Subject: [PATCH RFC v2 09/12] mm/hugetlb: Use hugetlb walker lock in hugetlb_vma_maps_page()
Date: Thu, 17 Nov 2022 20:10:22 -0500 [thread overview]
Message-ID: <20221118011025.2178986-10-peterx@redhat.com> (raw)
In-Reply-To: <20221118011025.2178986-1-peterx@redhat.com>
Hugetlb walker lock makes sure the pte_t* won't go away from under us.
Signed-off-by: Peter Xu <peterx@redhat.com>
---
fs/hugetlbfs/inode.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index fdb16246f46e..265508981ba1 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -387,21 +387,24 @@ static bool hugetlb_vma_maps_page(struct vm_area_struct *vma,
unsigned long addr, struct page *page)
{
pte_t *ptep, pte;
+ bool result = false;
+ hugetlb_walker_lock();
ptep = huge_pte_offset(vma->vm_mm, addr,
huge_page_size(hstate_vma(vma)));
if (!ptep)
- return false;
+ goto out;
pte = huge_ptep_get(ptep);
if (huge_pte_none(pte) || !pte_present(pte))
- return false;
+ goto out;
if (pte_page(pte) == page)
- return true;
-
- return false;
+ result = true;
+out:
+ hugetlb_walker_unlock();
+ return result;
}
/*
--
2.37.3
next prev parent reply other threads:[~2022-11-18 1:13 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-18 1:10 [PATCH RFC v2 00/12] mm/hugetlb: Make huge_pte_offset() thread-safe for pmd unshare Peter Xu
2022-11-18 1:10 ` [PATCH RFC v2 01/12] mm/hugetlb: Let vma_offset_start() to return start Peter Xu
2022-11-18 1:10 ` [PATCH RFC v2 02/12] mm/hugetlb: Move swap entry handling into vma lock for fault Peter Xu
2022-11-18 1:35 ` Peter Xu
2022-11-18 1:10 ` [PATCH RFC v2 03/12] mm/hugetlb: Don't wait for migration entry during follow page Peter Xu
2022-11-18 1:10 ` [PATCH RFC v2 04/12] mm/hugetlb: Add pgtable walker lock Peter Xu
2022-11-18 1:10 ` [PATCH RFC v2 05/12] mm/hugetlb: Make userfaultfd_huge_must_wait() safe to pmd unshare Peter Xu
2022-11-18 1:10 ` [PATCH RFC v2 06/12] mm/hugetlb: Protect huge_pmd_share() with walker lock Peter Xu
2022-11-18 1:17 ` Peter Xu
2022-11-18 1:10 ` [PATCH RFC v2 07/12] mm/hugetlb: Use hugetlb walker lock in hugetlb_follow_page_mask() Peter Xu
2022-11-18 1:10 ` [PATCH RFC v2 08/12] mm/hugetlb: Use hugetlb walker lock in follow_hugetlb_page() Peter Xu
2022-11-18 1:10 ` Peter Xu [this message]
2022-11-18 1:10 ` [PATCH RFC v2 10/12] mm/hugetlb: Use hugetlb walker lock in walk_hugetlb_range() Peter Xu
2022-11-18 1:11 ` [PATCH RFC v2 11/12] mm/hugetlb: Use hugetlb walker lock in page_vma_mapped_walk() Peter Xu
2022-11-18 1:11 ` [PATCH RFC v2 12/12] mm/hugetlb: Introduce hugetlb_walk() Peter Xu
2022-11-23 9:40 ` [PATCH RFC v2 00/12] mm/hugetlb: Make huge_pte_offset() thread-safe for pmd unshare David Hildenbrand
2022-11-23 15:09 ` Peter Xu
2022-11-23 18:21 ` Mike Kravetz
2022-11-23 18:56 ` Peter Xu
2022-11-23 19:31 ` David Hildenbrand
2022-11-25 9:43 ` David Hildenbrand
2022-11-25 13:55 ` Peter Xu
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