From: Peter Xu <peterx@redhat.com>
To: linux-kernel@vger.kernel.org, linux-mm@kvack.org
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>,
peterx@redhat.com, Andrew Morton <akpm@linux-foundation.org>,
Mike Kravetz <mike.kravetz@oracle.com>,
Jerome Glisse <jglisse@redhat.com>,
Miaohe Lin <linmiaohe@huawei.com>,
Nadav Amit <nadav.amit@gmail.com>,
Hugh Dickins <hughd@google.com>,
Matthew Wilcox <willy@infradead.org>,
Jason Gunthorpe <jgg@ziepe.ca>,
"Kirill A . Shutemov" <kirill@shutemov.name>,
Andrea Arcangeli <aarcange@redhat.com>,
Axel Rasmussen <axelrasmussen@google.com>
Subject: [PATCH v3 18/27] hugetlb/userfaultfd: Hook page faults for uffd write protection
Date: Thu, 27 May 2021 16:23:11 -0400 [thread overview]
Message-ID: <20210527202311.31937-1-peterx@redhat.com> (raw)
In-Reply-To: <20210527201927.29586-1-peterx@redhat.com>
Hook up hugetlbfs_fault() with the capability to handle userfaultfd-wp faults.
We do this slightly earlier than hugetlb_cow() so that we can avoid taking some
extra locks that we definitely don't need.
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
---
mm/hugetlb.c | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 69a4b551c157..4cbbffd50080 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -4980,6 +4980,25 @@ vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
if (unlikely(!pte_same(entry, huge_ptep_get(ptep))))
goto out_ptl;
+ /* Handle userfault-wp first, before trying to lock more pages */
+ if (userfaultfd_wp(vma) && huge_pte_uffd_wp(huge_ptep_get(ptep)) &&
+ (flags & FAULT_FLAG_WRITE) && !huge_pte_write(entry)) {
+ struct vm_fault vmf = {
+ .vma = vma,
+ .address = haddr,
+ .flags = flags,
+ };
+
+ spin_unlock(ptl);
+ if (pagecache_page) {
+ unlock_page(pagecache_page);
+ put_page(pagecache_page);
+ }
+ mutex_unlock(&hugetlb_fault_mutex_table[hash]);
+ i_mmap_unlock_read(mapping);
+ return handle_userfault(&vmf, VM_UFFD_WP);
+ }
+
/*
* hugetlb_cow() requires page locks of pte_page(entry) and
* pagecache_page, so here we need take the former one
--
2.31.1
next prev parent reply other threads:[~2021-05-27 20:23 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-27 20:19 [PATCH v3 00/27] userfaultfd-wp: Support shmem and hugetlbfs Peter Xu
2021-05-27 20:19 ` [PATCH v3 01/27] mm/shmem: Unconditionally set pte dirty in mfill_atomic_install_pte Peter Xu
2021-05-27 20:19 ` [PATCH v3 02/27] shmem/userfaultfd: Take care of UFFDIO_COPY_MODE_WP Peter Xu
2021-05-27 20:19 ` [PATCH v3 03/27] mm: Clear vmf->pte after pte_unmap_same() returns Peter Xu
2021-05-27 20:19 ` [PATCH v3 04/27] mm/userfaultfd: Introduce special pte for unmapped file-backed mem Peter Xu
2021-05-28 8:32 ` Alistair Popple
2021-05-28 12:56 ` Peter Xu
2021-06-03 11:53 ` Alistair Popple
2021-06-03 14:51 ` Peter Xu
2021-06-04 0:55 ` Alistair Popple
2021-06-04 3:14 ` Hugh Dickins
2021-06-04 6:16 ` Alistair Popple
2021-06-04 16:01 ` Peter Xu
2021-06-08 13:18 ` Alistair Popple
2021-06-09 13:06 ` Alistair Popple
2021-06-09 14:43 ` Peter Xu
2021-05-27 20:21 ` [PATCH v3 05/27] mm/swap: Introduce the idea of special swap ptes Peter Xu
2021-05-27 20:21 ` [PATCH v3 06/27] shmem/userfaultfd: Handle uffd-wp special pte in page fault handler Peter Xu
2021-06-17 8:59 ` Alistair Popple
2021-06-17 15:10 ` Peter Xu
2021-05-27 20:21 ` [PATCH v3 07/27] mm: Drop first_index/last_index in zap_details Peter Xu
2021-06-21 12:20 ` Alistair Popple
2021-05-27 20:21 ` [PATCH v3 08/27] mm: Introduce zap_details.zap_flags Peter Xu
2021-06-21 12:09 ` Alistair Popple
2021-06-21 16:16 ` Peter Xu
2021-06-22 2:07 ` Alistair Popple
2021-05-27 20:21 ` [PATCH v3 09/27] mm: Introduce ZAP_FLAG_SKIP_SWAP Peter Xu
2021-06-21 12:36 ` Alistair Popple
2021-06-21 16:26 ` Peter Xu
2021-06-22 2:11 ` Alistair Popple
2021-05-27 20:21 ` [PATCH v3 10/27] mm: Pass zap_flags into unmap_mapping_pages() Peter Xu
2021-05-27 20:22 ` [PATCH v3 11/27] shmem/userfaultfd: Persist uffd-wp bit across zapping for file-backed Peter Xu
2021-06-21 8:41 ` Alistair Popple
2021-06-22 0:40 ` Peter Xu
2021-06-22 12:47 ` Alistair Popple
2021-06-22 15:44 ` Peter Xu
2021-06-23 6:04 ` Alistair Popple
2021-06-23 15:31 ` Peter Xu
2021-07-06 5:40 ` Alistair Popple
2021-07-06 15:35 ` Peter Xu
2021-07-08 2:49 ` Alistair Popple
2021-05-27 20:22 ` [PATCH v3 12/27] shmem/userfaultfd: Allow wr-protect none pte for file-backed mem Peter Xu
2021-05-27 20:22 ` [PATCH v3 13/27] shmem/userfaultfd: Allows file-back mem to be uffd wr-protected on thps Peter Xu
2021-05-27 20:22 ` [PATCH v3 14/27] shmem/userfaultfd: Handle the left-overed special swap ptes Peter Xu
2021-05-27 20:22 ` [PATCH v3 15/27] shmem/userfaultfd: Pass over uffd-wp special swap pte when fork() Peter Xu
2021-05-27 20:23 ` [PATCH v3 16/27] mm/hugetlb: Drop __unmap_hugepage_range definition from hugetlb.h Peter Xu
2021-05-27 20:23 ` [PATCH v3 17/27] mm/hugetlb: Introduce huge pte version of uffd-wp helpers Peter Xu
2021-05-27 20:23 ` Peter Xu [this message]
2021-05-27 20:23 ` [PATCH v3 19/27] hugetlb/userfaultfd: Take care of UFFDIO_COPY_MODE_WP Peter Xu
2021-05-27 20:23 ` [PATCH v3 20/27] hugetlb/userfaultfd: Handle UFFDIO_WRITEPROTECT Peter Xu
2021-05-27 20:23 ` [PATCH v3 21/27] mm/hugetlb: Introduce huge version of special swap pte helpers Peter Xu
2021-05-27 20:23 ` [PATCH v3 22/27] hugetlb/userfaultfd: Handle uffd-wp special pte in hugetlb pf handler Peter Xu
2021-05-27 20:23 ` [PATCH v3 23/27] hugetlb/userfaultfd: Allow wr-protect none ptes Peter Xu
2021-05-27 20:23 ` [PATCH v3 24/27] hugetlb/userfaultfd: Only drop uffd-wp special pte if required Peter Xu
2021-05-27 20:23 ` [PATCH v3 25/27] mm/pagemap: Recognize uffd-wp bit for shmem/hugetlbfs Peter Xu
2021-05-27 20:23 ` [PATCH v3 26/27] mm/userfaultfd: Enable write protection for shmem & hugetlbfs Peter Xu
2021-05-27 20:23 ` [PATCH v3 27/27] userfaultfd/selftests: Enable uffd-wp for shmem/hugetlbfs Peter Xu
2021-06-02 14:40 ` [PATCH v3 00/27] userfaultfd-wp: Support shmem and hugetlbfs Peter Xu
2021-06-02 22:36 ` Andrew Morton
2021-06-03 0:09 ` Peter Xu
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