The patch titled
Subject: mm/userfaultfd: fix a few thp pmd missing uffd-wp bit
has been added to the -mm tree. Its filename is
mm-userfaultfd-fix-a-few-thp-pmd-missing-uffd-wp-bit.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-userfaultfd-fix-a-few-thp-pmd-missing-uffd-wp-bit.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-userfaultfd-fix-a-few-thp-pmd-missing-uffd-wp-bit.patch
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The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Peter Xu <peterx@xxxxxxxxxx>
Subject: mm/userfaultfd: fix a few thp pmd missing uffd-wp bit
These include:
1. When remove migration pmd entry, should keep the uffd-wp bit from
swap pte. Note that we need to do this after setting write bit just in
case we need to remove it.
2. When change huge pmd and convert write -> read migration entry,
persist the same uffd-wp bit.
3. When convert pmd to swap entry, should drop the uffd-wp bit always.
Link: https://lkml.kernel.org/r/20210428225030.9708-4-peterx@xxxxxxxxxx
Signed-off-by: Peter Xu <peterx@xxxxxxxxxx>
Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: Axel Rasmussen <axelrasmussen@xxxxxxxxxx>
Cc: Brian Geffon <bgeffon@xxxxxxxxxx>
Cc: "Dr . David Alan Gilbert" <dgilbert@xxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Jerome Glisse <jglisse@xxxxxxxxxx>
Cc: Joe Perches <joe@xxxxxxxxxxx>
Cc: Kirill A. Shutemov <kirill@xxxxxxxxxxxxx>
Cc: Lokesh Gidra <lokeshgidra@xxxxxxxxxx>
Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Cc: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx>
Cc: Mina Almasry <almasrymina@xxxxxxxxxx>
Cc: Oliver Upton <oupton@xxxxxxxxxx>
Cc: Shaohua Li <shli@xxxxxx>
Cc: Shuah Khan <shuah@xxxxxxxxxx>
Cc: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
Cc: Wang Qing <wangqing@xxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/swapops.h | 2 ++
mm/huge_memory.c | 4 ++++
2 files changed, 6 insertions(+)
--- a/include/linux/swapops.h~mm-userfaultfd-fix-a-few-thp-pmd-missing-uffd-wp-bit
+++ a/include/linux/swapops.h
@@ -258,6 +258,8 @@ static inline swp_entry_t pmd_to_swp_ent
if (pmd_swp_soft_dirty(pmd))
pmd = pmd_swp_clear_soft_dirty(pmd);
+ if (pmd_swp_uffd_wp(pmd))
+ pmd = pmd_swp_clear_uffd_wp(pmd);
arch_entry = __pmd_to_swp_entry(pmd);
return swp_entry(__swp_type(arch_entry), __swp_offset(arch_entry));
}
--- a/mm/huge_memory.c~mm-userfaultfd-fix-a-few-thp-pmd-missing-uffd-wp-bit
+++ a/mm/huge_memory.c
@@ -1823,6 +1823,8 @@ int change_huge_pmd(struct vm_area_struc
newpmd = swp_entry_to_pmd(entry);
if (pmd_swp_soft_dirty(*pmd))
newpmd = pmd_swp_mksoft_dirty(newpmd);
+ if (pmd_swp_uffd_wp(*pmd))
+ newpmd = pmd_swp_mkuffd_wp(newpmd);
set_pmd_at(mm, addr, pmd, newpmd);
}
goto unlock;
@@ -3234,6 +3236,8 @@ void remove_migration_pmd(struct page_vm
pmde = pmd_mksoft_dirty(pmde);
if (is_write_migration_entry(entry))
pmde = maybe_pmd_mkwrite(pmde, vma);
+ if (pmd_swp_uffd_wp(*pvmw->pmd))
+ pmde = pmd_wrprotect(pmd_mkuffd_wp(pmde));
flush_cache_range(vma, mmun_start, mmun_start + HPAGE_PMD_SIZE);
if (PageAnon(new))
_
Patches currently in -mm which might be from peterx@xxxxxxxxxx are
mm-hugetlb-fix-f_seal_future_write.patch
mm-hugetlb-fix-cow-where-page-writtable-in-child.patch
mm-gup_benchmark-support-threading.patch
userfaultfd-selftests-use-user-mode-only.patch
userfaultfd-selftests-remove-the-time-check-on-delayed-uffd.patch
userfaultfd-selftests-dropping-verify-check-in-locking_thread.patch
userfaultfd-selftests-only-dump-counts-if-mode-enabled.patch
userfaultfd-selftests-unify-error-handling.patch
mm-thp-simplify-copying-of-huge-zero-page-pmd-when-fork.patch
mm-userfaultfd-fix-uffd-wp-special-cases-for-fork.patch
mm-userfaultfd-fix-a-few-thp-pmd-missing-uffd-wp-bit.patch
mm-userfaultfd-fail-uffd-wp-registeration-if-not-supported.patch
mm-pagemap-export-uffd-wp-protection-information.patch
userfaultfd-selftests-add-pagemap-uffd-wp-test.patch
