On 04/12/2023 17:26, James Houghton wrote: > Make it impossible to create a sw-dirty, hw-clean PTE with pte_modify. > Such a PTE should be impossible to create, and there may be places that > assume that pte_dirty() implies pte_hw_dirty(). > > Signed-off-by: James Houghton <jthoughton@xxxxxxxxxx> Reviewed-by: Ryan Roberts <ryan.roberts@xxxxxxx> > > diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h > index b19a8aee684c..79ce70fbb751 100644 > --- a/arch/arm64/include/asm/pgtable.h > +++ b/arch/arm64/include/asm/pgtable.h > @@ -834,6 +834,12 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) > pte = set_pte_bit(pte, __pgprot(PTE_DIRTY)); > > pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask); > + /* > + * If we end up clearing hw dirtiness for a sw-dirty PTE, set hardware > + * dirtiness again. > + */ > + if (pte_sw_dirty(pte)) > + pte = pte_mkdirty(pte); > return pte; > } >
