Merge remote-tracking branch 'torvalds/master' into perf/core

[linux-2.6-microblaze.git] / mm / page_vma_mapped.c

diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c
index 2cf01d9..e37bd43 100644 (file)
--- a/mm/page_vma_mapped.c
+++ b/mm/page_vma_mapped.c
@@ -212,23 +212,34 @@ restart:
                        pvmw->ptl = NULL;
                }
        } else if (!pmd_present(pmde)) {
+               /*
+                * If PVMW_SYNC, take and drop THP pmd lock so that we
+                * cannot return prematurely, while zap_huge_pmd() has
+                * cleared *pmd but not decremented compound_mapcount().
+                */
+               if ((pvmw->flags & PVMW_SYNC) &&
+                   PageTransCompound(pvmw->page)) {
+                       spinlock_t *ptl = pmd_lock(mm, pvmw->pmd);
+
+                       spin_unlock(ptl);
+               }
                return false;
        }
        if (!map_pte(pvmw))
                goto next_pte;
        while (1) {
+               unsigned long end;
+
                if (check_pte(pvmw))
                        return true;
 next_pte:
                /* Seek to next pte only makes sense for THP */
                if (!PageTransHuge(pvmw->page) || PageHuge(pvmw->page))
                        return not_found(pvmw);
+               end = vma_address_end(pvmw->page, pvmw->vma);
                do {
                        pvmw->address += PAGE_SIZE;
-                       if (pvmw->address >= pvmw->vma->vm_end ||
-                           pvmw->address >=
-                                       __vma_address(pvmw->page, pvmw->vma) +
-                                       thp_size(pvmw->page))
+                       if (pvmw->address >= end)
                                return not_found(pvmw);
                        /* Did we cross page table boundary? */
                        if (pvmw->address % PMD_SIZE == 0) {
@@ -266,14 +277,10 @@ int page_mapped_in_vma(struct page *page, struct vm_area_struct *vma)
                .vma = vma,
                .flags = PVMW_SYNC,
        };
-       unsigned long start, end;
-
-       start = __vma_address(page, vma);
-       end = start + thp_size(page) - PAGE_SIZE;
 
-       if (unlikely(end < vma->vm_start || start >= vma->vm_end))
+       pvmw.address = vma_address(page, vma);
+       if (pvmw.address == -EFAULT)
                return 0;
-       pvmw.address = max(start, vma->vm_start);
        if (!page_vma_mapped_walk(&pvmw))
                return 0;
        page_vma_mapped_walk_done(&pvmw);