54e6cd42a1
Set _PAGE_DIRTY only if _PAGE_MODIFIED is set in {pmd,pte}_mkwrite().
Otherwise, _PAGE_DIRTY silences the TLB modify exception and make us
have no chance to mark a pmd/pte dirty (_PAGE_MODIFIED) for software.
Reviewed-by: Guo Ren <guoren@kernel.org>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>