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| author | David S. Miller <davem@davemloft.net> | 2021-03-26 01:31:22 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2021-03-26 01:31:22 +0300 |
| commit | efd13b71a3fa31413f8d15342e01d44b60b0a432 (patch) | |
| tree | 2ed1b299e25538c5a60485a1047507b49d3e0ecf /mm/memory.c | |
| parent | 84c7f6c33f42a12eb036ebf0f0e3670799304120 (diff) | |
| parent | 002322402dafd846c424ffa9240a937f49b48c42 (diff) | |
| download | linux-efd13b71a3fa31413f8d15342e01d44b60b0a432.tar.xz | |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'mm/memory.c')
| -rw-r--r-- | mm/memory.c | 16 |
1 files changed, 9 insertions, 7 deletions
diff --git a/mm/memory.c b/mm/memory.c index c8e357627318..5efa07fb6cdc 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -809,12 +809,8 @@ copy_present_page(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma pte_t *dst_pte, pte_t *src_pte, unsigned long addr, int *rss, struct page **prealloc, pte_t pte, struct page *page) { - struct mm_struct *src_mm = src_vma->vm_mm; struct page *new_page; - if (!is_cow_mapping(src_vma->vm_flags)) - return 1; - /* * What we want to do is to check whether this page may * have been pinned by the parent process. If so, @@ -828,9 +824,7 @@ copy_present_page(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma * the page count. That might give false positives for * for pinning, but it will work correctly. */ - if (likely(!atomic_read(&src_mm->has_pinned))) - return 1; - if (likely(!page_maybe_dma_pinned(page))) + if (likely(!page_needs_cow_for_dma(src_vma, page))) return 1; new_page = *prealloc; @@ -3103,6 +3097,14 @@ static vm_fault_t do_wp_page(struct vm_fault *vmf) return handle_userfault(vmf, VM_UFFD_WP); } + /* + * Userfaultfd write-protect can defer flushes. Ensure the TLB + * is flushed in this case before copying. + */ + if (unlikely(userfaultfd_wp(vmf->vma) && + mm_tlb_flush_pending(vmf->vma->vm_mm))) + flush_tlb_page(vmf->vma, vmf->address); + vmf->page = vm_normal_page(vma, vmf->address, vmf->orig_pte); if (!vmf->page) { /* |