Merge android-msm-wahoo-4.4-pi into -pi-qpr1android-9.0.0_r0.53

Change-Id: I3be7138b281eddc567b5a90dd151338002aeb089
Signed-off-by: Petri Gynther <pgynther@google.com>

2 files changed, 21 insertions, 6 deletions

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 0127b788272f..0a19fe8d4630 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1511,7 +1511,7 @@ int move_huge_pmd(struct vm_area_struct *vma, struct vm_area_struct *new_vma,
 	spinlock_t *old_ptl, *new_ptl;
 	int ret = 0;
 	pmd_t pmd;
-
+	bool force_flush = false;
 	struct mm_struct *mm = vma->vm_mm;
 
 	if ((old_addr & ~HPAGE_PMD_MASK) ||
@@ -1539,6 +1539,8 @@ int move_huge_pmd(struct vm_area_struct *vma, struct vm_area_struct *new_vma,
 		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))
+			force_flush = true;
 		VM_BUG_ON(!pmd_none(*new_pmd));
 
 		if (pmd_move_must_withdraw(new_ptl, old_ptl)) {
@@ -1547,6 +1549,8 @@ int move_huge_pmd(struct vm_area_struct *vma, struct vm_area_struct *new_vma,
 			pgtable_trans_huge_deposit(mm, new_pmd, pgtable);
 		}
 		set_pmd_at(mm, new_addr, new_pmd, pmd_mksoft_dirty(pmd));
+		if (force_flush)
+			flush_tlb_range(vma, old_addr, old_addr + PMD_SIZE);
 		if (new_ptl != old_ptl)
 			spin_unlock(new_ptl);
 		spin_unlock(old_ptl);
diff --git a/mm/mremap.c b/mm/mremap.c
index fe7b7f65f4f4..450b306d473e 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -96,6 +96,8 @@ static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd,
 	struct mm_struct *mm = vma->vm_mm;
 	pte_t *old_pte, *new_pte, pte;
 	spinlock_t *old_ptl, *new_ptl;
+	bool force_flush = false;
+	unsigned long len = old_end - old_addr;
 
 	/*
 	 * When need_rmap_locks is true, we take the i_mmap_rwsem and anon_vma
@@ -143,12 +145,26 @@ static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd,
 		if (pte_none(*old_pte))
 			continue;
 		pte = ptep_get_and_clear(mm, old_addr, old_pte);
+		/*
+		 * If we are remapping a valid PTE, make sure
+		 * to flush TLB before we drop the PTL for the PTE.
+		 *
+		 * 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))
+			force_flush = true;
 		pte = move_pte(pte, new_vma->vm_page_prot, old_addr, new_addr);
 		pte = move_soft_dirty_pte(pte);
 		set_pte_at(mm, new_addr, new_pte, pte);
 	}
 
 	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);
@@ -168,7 +184,6 @@ 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 */
 
@@ -207,7 +222,6 @@ unsigned long move_page_tables(struct vm_area_struct *vma,
 					anon_vma_unlock_write(vma->anon_vma);
 			}
 			if (err > 0) {
-				need_flush = true;
 				continue;
 			} else if (!err) {
 				split_huge_page_pmd(vma, old_addr, old_pmd);
@@ -224,10 +238,7 @@ unsigned long move_page_tables(struct vm_area_struct *vma,
 			extent = LATENCY_LIMIT;
 		move_ptes(vma, old_pmd, old_addr, old_addr + extent,
 			  new_vma, new_pmd, new_addr, need_rmap_locks);
-		need_flush = true;
 	}
-	if (likely(need_flush))
-		flush_tlb_range(vma, old_end-len, old_addr);
 
 	mmu_notifier_invalidate_range_end(vma->vm_mm, mmun_start, mmun_end);