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| author | Peter Xu <peterx@redhat.com> | 2022-05-12 20:22:54 -0700 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2022-05-13 07:20:11 -0700 |
| commit | 5a90d5a103c2badfcf12d48e2fec350969e3f486 (patch) | |
| tree | 86e472727415249843f8f422011d859bedbe95fd /mm | |
| parent | 6041c69179034278ac6d57f90a55b09e588f4b90 (diff) | |
| download | linux-stable-5a90d5a103c2badfcf12d48e2fec350969e3f486.tar.gz linux-stable-5a90d5a103c2badfcf12d48e2fec350969e3f486.tar.bz2 linux-stable-5a90d5a103c2badfcf12d48e2fec350969e3f486.zip | |
mm/hugetlb: handle UFFDIO_WRITEPROTECT
This starts from passing cp_flags into hugetlb_change_protection() so
hugetlb will be able to handle MM_CP_UFFD_WP[_RESOLVE] requests.
huge_pte_clear_uffd_wp() is introduced to handle the case where the
UFFDIO_WRITEPROTECT is requested upon migrating huge page entries.
Link: https://lkml.kernel.org/r/20220405014906.14708-1-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: "Kirill A . Shutemov" <kirill@shutemov.name>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/hugetlb.c | 13 | ||||
| -rw-r--r-- | mm/mprotect.c | 3 | ||||
| -rw-r--r-- | mm/userfaultfd.c | 8 |
3 files changed, 22 insertions, 2 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 2550b434cabd..4b8f413e011d 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -6233,7 +6233,8 @@ long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, } unsigned long hugetlb_change_protection(struct vm_area_struct *vma, - unsigned long address, unsigned long end, pgprot_t newprot) + unsigned long address, unsigned long end, + pgprot_t newprot, unsigned long cp_flags) { struct mm_struct *mm = vma->vm_mm; unsigned long start = address; @@ -6243,6 +6244,8 @@ unsigned long hugetlb_change_protection(struct vm_area_struct *vma, unsigned long pages = 0; bool shared_pmd = false; struct mmu_notifier_range range; + bool uffd_wp = cp_flags & MM_CP_UFFD_WP; + bool uffd_wp_resolve = cp_flags & MM_CP_UFFD_WP_RESOLVE; /* * In the case of shared PMDs, the area to flush could be beyond @@ -6289,6 +6292,10 @@ unsigned long hugetlb_change_protection(struct vm_area_struct *vma, entry = make_readable_migration_entry( swp_offset(entry)); newpte = swp_entry_to_pte(entry); + if (uffd_wp) + newpte = pte_swp_mkuffd_wp(newpte); + else if (uffd_wp_resolve) + newpte = pte_swp_clear_uffd_wp(newpte); set_huge_swap_pte_at(mm, address, ptep, newpte, huge_page_size(h)); pages++; @@ -6303,6 +6310,10 @@ unsigned long hugetlb_change_protection(struct vm_area_struct *vma, old_pte = huge_ptep_modify_prot_start(vma, address, ptep); pte = huge_pte_modify(old_pte, newprot); pte = arch_make_huge_pte(pte, shift, vma->vm_flags); + if (uffd_wp) + pte = huge_pte_mkuffd_wp(huge_pte_wrprotect(pte)); + else if (uffd_wp_resolve) + pte = huge_pte_clear_uffd_wp(pte); huge_ptep_modify_prot_commit(vma, address, ptep, old_pte, pte); pages++; } diff --git a/mm/mprotect.c b/mm/mprotect.c index cccad7974b3b..ba5592655ee3 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -460,7 +460,8 @@ unsigned long change_protection(struct mmu_gather *tlb, BUG_ON((cp_flags & MM_CP_UFFD_WP_ALL) == MM_CP_UFFD_WP_ALL); if (is_vm_hugetlb_page(vma)) - pages = hugetlb_change_protection(vma, start, end, newprot); + pages = hugetlb_change_protection(vma, start, end, newprot, + cp_flags); else pages = change_protection_range(tlb, vma, start, end, newprot, cp_flags); diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c index be2a61f4b55e..01edc18902c5 100644 --- a/mm/userfaultfd.c +++ b/mm/userfaultfd.c @@ -705,6 +705,7 @@ int mwriteprotect_range(struct mm_struct *dst_mm, unsigned long start, atomic_t *mmap_changing) { struct vm_area_struct *dst_vma; + unsigned long page_mask; struct mmu_gather tlb; pgprot_t newprot; int err; @@ -742,6 +743,13 @@ int mwriteprotect_range(struct mm_struct *dst_mm, unsigned long start, if (!vma_is_anonymous(dst_vma)) goto out_unlock; + if (is_vm_hugetlb_page(dst_vma)) { + err = -EINVAL; + page_mask = vma_kernel_pagesize(dst_vma) - 1; + if ((start & page_mask) || (len & page_mask)) + goto out_unlock; + } + if (enable_wp) newprot = vm_get_page_prot(dst_vma->vm_flags & ~(VM_WRITE)); else |