From: Peter Xu <peterx@redhat.com>
To: linux-mm@kvack.org, linux-kernel@vger.kernel.org
Cc: James Houghton <jthoughton@google.com>,
Jann Horn <jannh@google.com>,
peterx@redhat.com, Andrew Morton <akpm@linux-foundation.org>,
Andrea Arcangeli <aarcange@redhat.com>,
Rik van Riel <riel@surriel.com>,
Nadav Amit <nadav.amit@gmail.com>,
Miaohe Lin <linmiaohe@huawei.com>,
Muchun Song <songmuchun@bytedance.com>,
Mike Kravetz <mike.kravetz@oracle.com>,
David Hildenbrand <david@redhat.com>
Subject: [PATCH 07/10] mm/hugetlb: Make follow_hugetlb_page() safe to pmd unshare
Date: Tue, 29 Nov 2022 14:35:23 -0500 [thread overview]
Message-ID: <20221129193526.3588187-8-peterx@redhat.com> (raw)
In-Reply-To: <20221129193526.3588187-1-peterx@redhat.com>
Since follow_hugetlb_page() walks the pgtable, it needs the vma lock
to make sure the pgtable page will not be freed concurrently.
Signed-off-by: Peter Xu <peterx@redhat.com>
---
mm/hugetlb.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index d6bb1d22f1c4..df645a5824e3 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -6290,6 +6290,7 @@ long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
break;
}
+ hugetlb_vma_lock_read(vma);
/*
* Some archs (sparc64, sh*) have multiple pte_ts to
* each hugepage. We have to make sure we get the
@@ -6314,6 +6315,7 @@ long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
!hugetlbfs_pagecache_present(h, vma, vaddr)) {
if (pte)
spin_unlock(ptl);
+ hugetlb_vma_unlock_read(vma);
remainder = 0;
break;
}
@@ -6335,6 +6337,8 @@ long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
if (pte)
spin_unlock(ptl);
+ hugetlb_vma_unlock_read(vma);
+
if (flags & FOLL_WRITE)
fault_flags |= FAULT_FLAG_WRITE;
else if (unshare)
@@ -6394,6 +6398,7 @@ long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
remainder -= pages_per_huge_page(h);
i += pages_per_huge_page(h);
spin_unlock(ptl);
+ hugetlb_vma_unlock_read(vma);
continue;
}
@@ -6421,6 +6426,7 @@ long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
if (WARN_ON_ONCE(!try_grab_folio(pages[i], refs,
flags))) {
spin_unlock(ptl);
+ hugetlb_vma_unlock_read(vma);
remainder = 0;
err = -ENOMEM;
break;
@@ -6432,6 +6438,7 @@ long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
i += refs;
spin_unlock(ptl);
+ hugetlb_vma_unlock_read(vma);
}
*nr_pages = remainder;
/*
--
2.37.3
next prev parent reply other threads:[~2022-11-29 19:38 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-29 19:35 [PATCH 00/10] mm/hugetlb: Make huge_pte_offset() thread-safe for pmd unshare Peter Xu
2022-11-29 19:35 ` [PATCH 01/10] mm/hugetlb: Let vma_offset_start() to return start Peter Xu
2022-11-30 10:11 ` David Hildenbrand
2022-11-29 19:35 ` [PATCH 02/10] mm/hugetlb: Don't wait for migration entry during follow page Peter Xu
2022-11-30 4:37 ` Mike Kravetz
2022-11-30 10:15 ` David Hildenbrand
2022-11-29 19:35 ` [PATCH 03/10] mm/hugetlb: Document huge_pte_offset usage Peter Xu
2022-11-30 4:55 ` Mike Kravetz
2022-11-30 15:58 ` Peter Xu
2022-12-05 21:47 ` Mike Kravetz
2022-11-30 10:21 ` David Hildenbrand
2022-11-30 10:24 ` David Hildenbrand
2022-11-30 16:09 ` Peter Xu
2022-11-30 16:11 ` David Hildenbrand
2022-11-30 16:25 ` Peter Xu
2022-11-30 16:31 ` David Hildenbrand
2022-11-29 19:35 ` [PATCH 04/10] mm/hugetlb: Move swap entry handling into vma lock when faulted Peter Xu
2022-12-05 22:14 ` Mike Kravetz
2022-12-05 23:36 ` Peter Xu
2022-11-29 19:35 ` [PATCH 05/10] mm/hugetlb: Make userfaultfd_huge_must_wait() safe to pmd unshare Peter Xu
2022-11-30 16:08 ` David Hildenbrand
2022-12-05 22:23 ` Mike Kravetz
2022-11-29 19:35 ` [PATCH 06/10] mm/hugetlb: Make hugetlb_follow_page_mask() " Peter Xu
2022-11-30 16:09 ` David Hildenbrand
2022-12-05 22:29 ` Mike Kravetz
2022-11-29 19:35 ` Peter Xu [this message]
2022-11-30 16:09 ` [PATCH 07/10] mm/hugetlb: Make follow_hugetlb_page() " David Hildenbrand
2022-12-05 22:45 ` Mike Kravetz
2022-11-29 19:35 ` [PATCH 08/10] mm/hugetlb: Make walk_hugetlb_range() " Peter Xu
2022-11-30 16:11 ` David Hildenbrand
2022-12-05 23:33 ` Mike Kravetz
2022-12-05 23:52 ` John Hubbard
2022-12-06 16:45 ` Peter Xu
2022-12-06 18:50 ` Mike Kravetz
2022-12-06 21:03 ` John Hubbard
2022-12-06 21:51 ` Peter Xu
2022-12-06 22:31 ` John Hubbard
2022-12-07 0:07 ` Peter Xu
2022-12-07 2:38 ` John Hubbard
2022-12-07 14:58 ` Peter Xu
2022-11-29 19:35 ` [PATCH 09/10] mm/hugetlb: Make page_vma_mapped_walk() " Peter Xu
2022-11-30 16:18 ` David Hildenbrand
2022-11-30 16:32 ` Peter Xu
2022-11-30 16:39 ` David Hildenbrand
2022-12-05 23:52 ` Mike Kravetz
2022-12-06 17:10 ` Mike Kravetz
2022-12-06 17:39 ` Peter Xu
2022-12-06 17:43 ` Peter Xu
2022-12-06 19:58 ` Mike Kravetz
2022-11-29 19:35 ` [PATCH 10/10] mm/hugetlb: Introduce hugetlb_walk() Peter Xu
2022-11-30 5:18 ` Eric Biggers
2022-11-30 15:37 ` Peter Xu
2022-12-06 0:21 ` Mike Kravetz
2022-11-29 20:49 ` [PATCH 00/10] mm/hugetlb: Make huge_pte_offset() thread-safe for pmd unshare Andrew Morton
2022-11-29 21:19 ` Peter Xu
2022-11-29 21:26 ` Andrew Morton
2022-11-29 20:51 ` Andrew Morton
2022-11-29 21:36 ` Peter Xu
2022-11-30 9:46 ` David Hildenbrand
2022-11-30 16:23 ` Peter Xu
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=20221129193526.3588187-8-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=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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).