From 102a0743326a03cd1a1202ceda21e175b7d3575c Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:20:52 +0000
Subject: [PATCH] add new system file
---
kernel/mm/khugepaged.c | 18 ++++++++++--------
1 files changed, 10 insertions(+), 8 deletions(-)
diff --git a/kernel/mm/khugepaged.c b/kernel/mm/khugepaged.c
index 6ddc276..d0ec863 100644
--- a/kernel/mm/khugepaged.c
+++ b/kernel/mm/khugepaged.c
@@ -623,6 +623,10 @@
result = SCAN_PTE_NON_PRESENT;
goto out;
}
+ if (pte_uffd_wp(pteval)) {
+ result = SCAN_PTE_UFFD_WP;
+ goto out;
+ }
page = vm_normal_page(vma, address, pteval);
if (unlikely(!page)) {
result = SCAN_PAGE_NULL;
@@ -1464,14 +1468,6 @@
if (!hugepage_vma_check(vma, vma->vm_flags | VM_HUGEPAGE))
return;
- /*
- * Symmetry with retract_page_tables(): Exclude MAP_PRIVATE mappings
- * that got written to. Without this, we'd have to also lock the
- * anon_vma if one exists.
- */
- if (vma->anon_vma)
- return;
-
hpage = find_lock_page(vma->vm_file->f_mapping,
linear_page_index(vma, haddr));
if (!hpage)
@@ -1545,6 +1541,10 @@
}
/* step 4: collapse pmd */
+ /* we make no change to anon, but protect concurrent anon page lookup */
+ if (vma->anon_vma)
+ anon_vma_lock_write(vma->anon_vma);
+
mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, NULL, mm, haddr,
haddr + HPAGE_PMD_SIZE);
mmu_notifier_invalidate_range_start(&range);
@@ -1555,6 +1555,8 @@
mmu_notifier_invalidate_range_end(&range);
pte_free(mm, pmd_pgtable(_pmd));
+ if (vma->anon_vma)
+ anon_vma_unlock_write(vma->anon_vma);
i_mmap_unlock_write(vma->vm_file->f_mapping);
drop_hpage:
--
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