Merging upstream version 4.19.260.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 23 insertions, 3 deletions

diff --git a/mm/mmap.c b/mm/mmap.c
index bb8ba3258..38541885e 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1640,8 +1640,12 @@ int vma_wants_writenotify(struct vm_area_struct *vma, pgprot_t vm_page_prot)
 	    pgprot_val(vm_pgprot_modify(vm_page_prot, vm_flags)))
 		return 0;
 
-	/* Do we need to track softdirty? */
-	if (IS_ENABLED(CONFIG_MEM_SOFT_DIRTY) && !(vm_flags & VM_SOFTDIRTY))
+	/*
+	 * Do we need to track softdirty? hugetlb does not support softdirty
+	 * tracking yet.
+	 */
+	if (IS_ENABLED(CONFIG_MEM_SOFT_DIRTY) && !(vm_flags & VM_SOFTDIRTY) &&
+	    !is_vm_hugetlb_page(vma))
 		return 1;
 
 	/* Specialty mapping? */
@@ -1821,7 +1825,6 @@ unmap_and_free_vma:
 
 	/* Undo any partial mapping done by a device driver. */
 	unmap_region(mm, vma, prev, vma->vm_start, vma->vm_end);
-	charged = 0;
 	if (vm_flags & VM_SHARED)
 		mapping_unmap_writable(file->f_mapping);
 allow_write_and_free_vma:
@@ -2564,11 +2567,28 @@ static void unmap_region(struct mm_struct *mm,
 {
 	struct vm_area_struct *next = prev ? prev->vm_next : mm->mmap;
 	struct mmu_gather tlb;
+	struct vm_area_struct *cur_vma;
 
 	lru_add_drain();
 	tlb_gather_mmu(&tlb, mm, start, end);
 	update_hiwater_rss(mm);
 	unmap_vmas(&tlb, vma, start, end);
+
+	/*
+	 * Ensure we have no stale TLB entries by the time this mapping is
+	 * removed from the rmap.
+	 * Note that we don't have to worry about nested flushes here because
+	 * we're holding the mm semaphore for removing the mapping - so any
+	 * concurrent flush in this region has to be coming through the rmap,
+	 * and we synchronize against that using the rmap lock.
+	 */
+	for (cur_vma = vma; cur_vma; cur_vma = cur_vma->vm_next) {
+		if ((cur_vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) != 0) {
+			tlb_flush_mmu(&tlb);
+			break;
+		}
+	}
+
 	free_pgtables(&tlb, vma, prev ? prev->vm_end : FIRST_USER_ADDRESS,
 				 next ? next->vm_start : USER_PGTABLES_CEILING);
 	tlb_finish_mmu(&tlb, start, end);