xen-gntdev: Use map->vma for checking map validity

The is_mapped flag used to be set at the completion of the map operation,
but was not checked in all error paths. Use map->vma instead, which will
now be cleared if the initial grant mapping fails.

Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

1 files changed, 2 insertions, 6 deletions

diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index 75f8037c9833..4ca4262d3d19 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -77,7 +77,6 @@ struct grant_map {
         int index;
         int count;
         int flags;
-        int is_mapped;
         atomic_t users;
         struct unmap_notify notify;
         struct ioctl_gntdev_grant_ref *grants;
@@ -322,7 +321,6 @@ static void gntdev_vma_close(struct vm_area_struct *vma)
         struct grant_map *map = vma->vm_private_data;
 
         pr_debug("close %p\n", vma);
-        map->is_mapped = 0;
         map->vma = NULL;
         vma->vm_private_data = NULL;
         gntdev_put_map(map);
@@ -347,8 +345,6 @@ static void mn_invl_range_start(struct mmu_notifier *mn,
         list_for_each_entry(map, &priv->maps, next) {
                 if (!map->vma)
                         continue;
-                if (!map->is_mapped)
-                        continue;
                 if (map->vma->vm_start >= end)
                         continue;
                 if (map->vma->vm_end <= start)
@@ -663,8 +659,6 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
         if (err)
                 goto out_put_map;
 
-        map->is_mapped = 1;
-
         if (!use_ptemod) {
                 for (i = 0; i < count; i++) {
                         err = vm_insert_page(vma, vma->vm_start + i*PAGE_SIZE,
@@ -681,6 +675,8 @@ unlock_out:
         return err;
 
 out_put_map:
+        if (use_ptemod)
+                map->vma = NULL;
         gntdev_put_map(map);
         return err;
 }