zero_pfn = page_to_pfn(ZERO_PAGE(0));
return 0;
}
-core_initcall(init_zero_pfn);
+early_initcall(init_zero_pfn);
void mm_trace_rss_stat(struct mm_struct *mm, int member, long count)
{
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,
* 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;
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) {
/*