Messages in this thread Patch in this message | | | From | Kamal Mostafa <> | Subject | [PATCH 3.13.y-ckt 07/57] xen/gntdevt: Fix race condition in gntdev_release() | Date | Tue, 22 Sep 2015 10:47:56 -0700 |
| |
3.13.11-ckt27 -stable review patch. If anyone has any objections, please let me know.
------------------
From: =?UTF-8?q?Marek=20Marczykowski-G=C3=B3recki?=
commit 30b03d05e07467b8c6ec683ea96b5bffcbcd3931 upstream.
While gntdev_release() is called the MMU notifier is still registered and can traverse priv->maps list even if no pages are mapped (which is the case -- gntdev_release() is called after all). But gntdev_release() will clear that list, so make sure that only one of those things happens at the same time.
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- drivers/xen/gntdev.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c index 0b58069..37c34b8 100644 --- a/drivers/xen/gntdev.c +++ b/drivers/xen/gntdev.c @@ -529,12 +529,14 @@ static int gntdev_release(struct inode *inode, struct file *flip) pr_debug("priv %p\n", priv); + mutex_lock(&priv->lock); while (!list_empty(&priv->maps)) { map = list_entry(priv->maps.next, struct grant_map, next); list_del(&map->next); gntdev_put_map(NULL /* already removed */, map); } WARN_ON(!list_empty(&priv->freeable_maps)); + mutex_unlock(&priv->lock); if (use_ptemod) mmu_notifier_unregister(&priv->mn, priv->mm); -- 1.9.1
| |