From: Peter Xu <peterx@redhat.com>
To: linux-mm@kvack.org, linux-kernel@vger.kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>,
Miaohe Lin <linmiaohe@huawei.com>,
David Hildenbrand <david@redhat.com>,
Nadav Amit <nadav.amit@gmail.com>,
peterx@redhat.com, Andrea Arcangeli <aarcange@redhat.com>,
Jann Horn <jannh@google.com>, John Hubbard <jhubbard@nvidia.com>,
Mike Kravetz <mike.kravetz@oracle.com>,
James Houghton <jthoughton@google.com>,
Rik van Riel <riel@surriel.com>,
Muchun Song <songmuchun@bytedance.com>
Subject: [PATCH v3 6/9] mm/hugetlb: Make hugetlb_follow_page_mask() safe to pmd unshare
Date: Fri, 9 Dec 2022 12:00:57 -0500 [thread overview]
Message-ID: <20221209170100.973970-7-peterx@redhat.com> (raw)
In-Reply-To: <20221209170100.973970-1-peterx@redhat.com>
Since hugetlb_follow_page_mask() walks the pgtable, it needs the vma lock
to make sure the pgtable page will not be freed concurrently.
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
---
mm/hugetlb.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 247702eb9f88..e3af347470ac 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -6227,9 +6227,10 @@ struct page *hugetlb_follow_page_mask(struct vm_area_struct *vma,
if (WARN_ON_ONCE(flags & FOLL_PIN))
return NULL;
+ hugetlb_vma_lock_read(vma);
pte = huge_pte_offset(mm, haddr, huge_page_size(h));
if (!pte)
- return NULL;
+ goto out_unlock;
ptl = huge_pte_lock(h, mm, pte);
entry = huge_ptep_get(pte);
@@ -6252,6 +6253,8 @@ struct page *hugetlb_follow_page_mask(struct vm_area_struct *vma,
}
out:
spin_unlock(ptl);
+out_unlock:
+ hugetlb_vma_unlock_read(vma);
return page;
}
--
2.37.3
next prev parent reply other threads:[~2022-12-09 17:03 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-09 17:00 [PATCH v3 0/9] mm/hugetlb: Make huge_pte_offset() thread-safe for pmd unshare Peter Xu
2022-12-09 17:00 ` [PATCH v3 1/9] mm/hugetlb: Let vma_offset_start() to return start Peter Xu
2022-12-09 17:00 ` [PATCH v3 2/9] mm/hugetlb: Don't wait for migration entry during follow page Peter Xu
2022-12-09 17:00 ` [PATCH v3 3/9] mm/hugetlb: Document huge_pte_offset usage Peter Xu
2022-12-09 17:00 ` [PATCH v3 4/9] mm/hugetlb: Move swap entry handling into vma lock when faulted Peter Xu
2022-12-09 17:00 ` [PATCH v3 5/9] mm/hugetlb: Make userfaultfd_huge_must_wait() safe to pmd unshare Peter Xu
2022-12-09 17:00 ` Peter Xu [this message]
2022-12-09 17:00 ` [PATCH v3 7/9] mm/hugetlb: Make follow_hugetlb_page() " Peter Xu
2022-12-09 17:00 ` [PATCH v3 8/9] mm/hugetlb: Make walk_hugetlb_range() " Peter Xu
2022-12-09 19:58 ` John Hubbard
2022-12-09 17:01 ` [PATCH v3 9/9] mm/hugetlb: Introduce hugetlb_walk() Peter Xu
2022-12-09 20:06 ` John Hubbard
2022-12-09 18:57 ` [PATCH v3 0/9] mm/hugetlb: Make huge_pte_offset() thread-safe for pmd unshare Mike Kravetz
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20221209170100.973970-7-peterx@redhat.com \
--to=peterx@redhat.com \
--cc=aarcange@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=david@redhat.com \
--cc=jannh@google.com \
--cc=jhubbard@nvidia.com \
--cc=jthoughton@google.com \
--cc=linmiaohe@huawei.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mike.kravetz@oracle.com \
--cc=nadav.amit@gmail.com \
--cc=riel@surriel.com \
--cc=songmuchun@bytedance.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.