diff options
| author | Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> | 2015-06-26 03:28:24 +0200 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2015-10-13 03:46:01 +0100 |
| commit | a97233643dcf324d983d92118099213fd08b7fba (patch) | |
| tree | 8ec7a4e164135cfcb2daeaece59d1b883053ae7e | |
| parent | f96051e525023fcb88fe5df5858cbee0371c0b4a (diff) | |
| download | kernel_samsung_smdk4412-a97233643dcf324d983d92118099213fd08b7fba.zip kernel_samsung_smdk4412-a97233643dcf324d983d92118099213fd08b7fba.tar.gz kernel_samsung_smdk4412-a97233643dcf324d983d92118099213fd08b7fba.tar.bz2 | |
xen/gntdevt: Fix race condition in gntdev_release()
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>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -rw-r--r-- | drivers/xen/gntdev.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c index c819ba1..5027662 100644 --- a/drivers/xen/gntdev.c +++ b/drivers/xen/gntdev.c @@ -493,11 +493,13 @@ 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(map); } + mutex_unlock(&priv->lock); if (use_ptemod) mmu_notifier_unregister(&priv->mn, priv->mm); |