[PATCH] uml: avoid already done dirtying

The PTE returned from handle_mm_fault is already marked as dirty and accessed
if needed.

Also, since this is not set with set_pte() (which sets NEWPAGE and NEWPROT as
needed), this wouldn't work anyway.

This version has been updated and fixed, thanks to some feedback from Jeff Dike.

Signed-off-by: Paolo 'Blaisorblade' Giarrusso <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

arch/um/kernel/trap_kern.c

···
 		pte = pte_offset_kernel(pmd, address);
 	} while(!pte_present(*pte));
 	err = 0;
-	*pte = pte_mkyoung(*pte);
-	if(pte_write(*pte)) *pte = pte_mkdirty(*pte);
+	WARN_ON(!pte_young(*pte) || (is_write && !pte_dirty(*pte)));
 	flush_tlb_page(vma, address);
 out:
 	up_read(&mm->mmap_sem);