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| author | Tianyang Zhang <zhangtianyang@loongson.cn> | 2025-11-09 11:02:01 +0300 |
|---|---|---|
| committer | Huacai Chen <chenhuacai@loongson.cn> | 2025-11-10 03:37:06 +0300 |
| commit | a073d637c8cfbfbab39b7272226a3fbf3b887580 (patch) | |
| tree | e853279e586cdb20be6cffb120fa1b35a2ee67eb | |
| parent | ce5ad03e459ecb3b4993a8f311fd4f2fb3e6ef81 (diff) | |
| download | linux-a073d637c8cfbfbab39b7272226a3fbf3b887580.tar.xz | |
LoongArch: Let {pte,pmd}_modify() record the status of _PAGE_DIRTY
Now if the PTE/PMD is dirty with _PAGE_DIRTY but without _PAGE_MODIFIED,
after {pte,pmd}_modify() we lose _PAGE_DIRTY, then {pte,pmd}_dirty()
return false and lead to data loss. This can happen in certain scenarios
such as HW PTW doesn't set _PAGE_MODIFIED automatically, so here we need
_PAGE_MODIFIED to record the dirty status (_PAGE_DIRTY).
The new modification involves checking whether the original PTE/PMD has
the _PAGE_DIRTY flag. If it exists, the _PAGE_MODIFIED bit is also set,
ensuring that the {pte,pmd}_dirty() interface can always return accurate
information.
Cc: stable@vger.kernel.org
Co-developed-by: Liupu Wang <wangliupu@loongson.cn>
Signed-off-by: Liupu Wang <wangliupu@loongson.cn>
Signed-off-by: Tianyang Zhang <zhangtianyang@loongson.cn>
| -rw-r--r-- | arch/loongarch/include/asm/pgtable.h | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/arch/loongarch/include/asm/pgtable.h b/arch/loongarch/include/asm/pgtable.h index bd128696e96d..03fb60432fde 100644 --- a/arch/loongarch/include/asm/pgtable.h +++ b/arch/loongarch/include/asm/pgtable.h @@ -424,6 +424,9 @@ static inline unsigned long pte_accessible(struct mm_struct *mm, pte_t a) static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) { + if (pte_val(pte) & _PAGE_DIRTY) + pte_val(pte) |= _PAGE_MODIFIED; + return __pte((pte_val(pte) & _PAGE_CHG_MASK) | (pgprot_val(newprot) & ~_PAGE_CHG_MASK)); } @@ -547,9 +550,11 @@ static inline struct page *pmd_page(pmd_t pmd) static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot) { - pmd_val(pmd) = (pmd_val(pmd) & _HPAGE_CHG_MASK) | - (pgprot_val(newprot) & ~_HPAGE_CHG_MASK); - return pmd; + if (pmd_val(pmd) & _PAGE_DIRTY) + pmd_val(pmd) |= _PAGE_MODIFIED; + + return __pmd((pmd_val(pmd) & _HPAGE_CHG_MASK) | + (pgprot_val(newprot) & ~_HPAGE_CHG_MASK)); } static inline pmd_t pmd_mkinvalid(pmd_t pmd) |