Commit 326c2597 authored Nov 05, 2015 by Laurent Dufour Committed by Linus Torvalds Nov 05, 2015

mm: clear pte in clear_soft_dirty()



As mentioned in the commit 56eecdb9 ("mm: Use ptep/pmdp_set_numa()
for updating _PAGE_NUMA bit"), architectures like ppc64 don't do tlb
flush in set_pte/pmd functions.

So when dealing with existing pte in clear_soft_dirty, the pte must be
cleared before being modified.

Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent c8f95ed1

fs/proc/task_mmu.c

+4 −3

Original line number	Diff line number	Diff line
		@@ -792,19 +792,20 @@ static inline void clear_soft_dirty(struct vm_area_struct *vma,
		pte_t ptent = *pte;

		if (pte_present(ptent)) {
		ptent = ptep_modify_prot_start(vma->vm_mm, addr, pte);
		ptent = pte_wrprotect(ptent);
		ptent = pte_clear_soft_dirty(ptent);
		ptep_modify_prot_commit(vma->vm_mm, addr, pte, ptent);
		} else if (is_swap_pte(ptent)) {
		ptent = pte_swp_clear_soft_dirty(ptent);
		}

		set_pte_at(vma->vm_mm, addr, pte, ptent);
		}
		}

		static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
		unsigned long addr, pmd_t *pmdp)
		{
		pmd_t pmd = *pmdp;
		pmd_t pmd = pmdp_huge_get_and_clear(vma->vm_mm, addr, pmdp);

		pmd = pmd_wrprotect(pmd);
		pmd = pmd_clear_soft_dirty(pmd);