diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h index 99c19b06d9a4..fdcb45999b26 100644 --- a/include/linux/huge_mm.h +++ b/include/linux/huge_mm.h @@ -43,7 +43,7 @@ extern int mincore_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, unsigned char *vec); extern bool move_huge_pmd(struct vm_area_struct *vma, unsigned long old_addr, unsigned long new_addr, unsigned long old_end, - pmd_t *old_pmd, pmd_t *new_pmd, bool *need_flush); + pmd_t *old_pmd, pmd_t *new_pmd); extern int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, unsigned long addr, pgprot_t newprot, int prot_numa); diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 58269f8ba7c4..deed97fba979 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1780,7 +1780,7 @@ static pmd_t move_soft_dirty_pmd(pmd_t pmd) bool move_huge_pmd(struct vm_area_struct *vma, unsigned long old_addr, unsigned long new_addr, unsigned long old_end, - pmd_t *old_pmd, pmd_t *new_pmd, bool *need_flush) + pmd_t *old_pmd, pmd_t *new_pmd) { spinlock_t *old_ptl, *new_ptl; pmd_t pmd; @@ -1811,7 +1811,7 @@ bool move_huge_pmd(struct vm_area_struct *vma, unsigned long old_addr, if (new_ptl != old_ptl) spin_lock_nested(new_ptl, SINGLE_DEPTH_NESTING); pmd = pmdp_huge_get_and_clear(mm, old_addr, old_pmd); - if (pmd_present(pmd) && pmd_dirty(pmd)) + if (pmd_present(pmd)) force_flush = true; VM_BUG_ON(!pmd_none(*new_pmd)); @@ -1822,12 +1822,10 @@ bool move_huge_pmd(struct vm_area_struct *vma, unsigned long old_addr, } pmd = move_soft_dirty_pmd(pmd); set_pmd_at(mm, new_addr, new_pmd, pmd); - if (new_ptl != old_ptl) - spin_unlock(new_ptl); if (force_flush) flush_tlb_range(vma, old_addr, old_addr + PMD_SIZE); - else - *need_flush = true; + if (new_ptl != old_ptl) + spin_unlock(new_ptl); spin_unlock(old_ptl); return true; } diff --git a/mm/mremap.c b/mm/mremap.c index 5c2e18505f75..a9617e72e6b7 100644 --- a/mm/mremap.c +++ b/mm/mremap.c @@ -115,7 +115,7 @@ static pte_t move_soft_dirty_pte(pte_t pte) static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd, unsigned long old_addr, unsigned long old_end, struct vm_area_struct *new_vma, pmd_t *new_pmd, - unsigned long new_addr, bool need_rmap_locks, bool *need_flush) + unsigned long new_addr, bool need_rmap_locks) { struct mm_struct *mm = vma->vm_mm; pte_t *old_pte, *new_pte, pte; @@ -163,15 +163,17 @@ static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd, pte = ptep_get_and_clear(mm, old_addr, old_pte); /* - * If we are remapping a dirty PTE, make sure + * If we are remapping a valid PTE, make sure * to flush TLB before we drop the PTL for the - * old PTE or we may race with page_mkclean(). + * PTE. * - * This check has to be done after we removed the - * old PTE from page tables or another thread may - * dirty it after the check and before the removal. + * NOTE! Both old and new PTL matter: the old one + * for racing with page_mkclean(), the new one to + * make sure the physical page stays valid until + * the TLB entry for the old mapping has been + * flushed. */ - if (pte_present(pte) && pte_dirty(pte)) + if (pte_present(pte)) force_flush = true; pte = move_pte(pte, new_vma->vm_page_prot, old_addr, new_addr); pte = move_soft_dirty_pte(pte); @@ -179,13 +181,11 @@ static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd, } arch_leave_lazy_mmu_mode(); + if (force_flush) + flush_tlb_range(vma, old_end - len, old_end); if (new_ptl != old_ptl) spin_unlock(new_ptl); pte_unmap(new_pte - 1); - if (force_flush) - flush_tlb_range(vma, old_end - len, old_end); - else - *need_flush = true; pte_unmap_unlock(old_pte - 1, old_ptl); if (need_rmap_locks) drop_rmap_locks(vma); @@ -198,7 +198,6 @@ unsigned long move_page_tables(struct vm_area_struct *vma, { unsigned long extent, next, old_end; pmd_t *old_pmd, *new_pmd; - bool need_flush = false; unsigned long mmun_start; /* For mmu_notifiers */ unsigned long mmun_end; /* For mmu_notifiers */ @@ -229,8 +228,7 @@ unsigned long move_page_tables(struct vm_area_struct *vma, if (need_rmap_locks) take_rmap_locks(vma); moved = move_huge_pmd(vma, old_addr, new_addr, - old_end, old_pmd, new_pmd, - &need_flush); + old_end, old_pmd, new_pmd); if (need_rmap_locks) drop_rmap_locks(vma); if (moved) @@ -246,10 +244,8 @@ unsigned long move_page_tables(struct vm_area_struct *vma, if (extent > next - new_addr) extent = next - new_addr; move_ptes(vma, old_pmd, old_addr, old_addr + extent, new_vma, - new_pmd, new_addr, need_rmap_locks, &need_flush); + new_pmd, new_addr, need_rmap_locks); } - if (need_flush) - flush_tlb_range(vma, old_end-len, old_addr); mmu_notifier_invalidate_range_end(vma->vm_mm, mmun_start, mmun_end);