Commit 00c115f1 authored by David Vrabel's avatar David Vrabel Committed by Luis Henriques

xen/gntdev: convert priv->lock to a mutex

commit 1401c00e upstream.

Unmapping may require sleeping and we unmap while holding priv->lock, so
convert it to a mutex.
Signed-off-by: default avatarDavid Vrabel <david.vrabel@citrix.com>
Reviewed-by: default avatarStefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
[ luis: 3.16 prereq for:
  30b03d05 xen/gntdevt: Fix race condition in gntdev_release() ]
Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
parent 1fa60c74
......@@ -67,7 +67,7 @@ struct gntdev_priv {
* Only populated if populate_freeable_maps == 1 */
struct list_head freeable_maps;
/* lock protects maps and freeable_maps */
spinlock_t lock;
struct mutex lock;
struct mm_struct *mm;
struct mmu_notifier mn;
};
......@@ -216,9 +216,9 @@ static void gntdev_put_map(struct gntdev_priv *priv, struct grant_map *map)
}
if (populate_freeable_maps && priv) {
spin_lock(&priv->lock);
mutex_lock(&priv->lock);
list_del(&map->next);
spin_unlock(&priv->lock);
mutex_unlock(&priv->lock);
}
if (map->pages && !use_ptemod)
......@@ -387,9 +387,9 @@ static void gntdev_vma_close(struct vm_area_struct *vma)
* not do any unmapping, since that has been done prior to
* closing the vma, but it may still iterate the unmap_ops list.
*/
spin_lock(&priv->lock);
mutex_lock(&priv->lock);
map->vma = NULL;
spin_unlock(&priv->lock);
mutex_unlock(&priv->lock);
}
vma->vm_private_data = NULL;
gntdev_put_map(priv, map);
......@@ -433,14 +433,14 @@ static void mn_invl_range_start(struct mmu_notifier *mn,
struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn);
struct grant_map *map;
spin_lock(&priv->lock);
mutex_lock(&priv->lock);
list_for_each_entry(map, &priv->maps, next) {
unmap_if_in_range(map, start, end);
}
list_for_each_entry(map, &priv->freeable_maps, next) {
unmap_if_in_range(map, start, end);
}
spin_unlock(&priv->lock);
mutex_unlock(&priv->lock);
}
static void mn_invl_page(struct mmu_notifier *mn,
......@@ -457,7 +457,7 @@ static void mn_release(struct mmu_notifier *mn,
struct grant_map *map;
int err;
spin_lock(&priv->lock);
mutex_lock(&priv->lock);
list_for_each_entry(map, &priv->maps, next) {
if (!map->vma)
continue;
......@@ -476,7 +476,7 @@ static void mn_release(struct mmu_notifier *mn,
err = unmap_grant_pages(map, /* offset */ 0, map->count);
WARN_ON(err);
}
spin_unlock(&priv->lock);
mutex_unlock(&priv->lock);
}
static struct mmu_notifier_ops gntdev_mmu_ops = {
......@@ -498,7 +498,7 @@ static int gntdev_open(struct inode *inode, struct file *flip)
INIT_LIST_HEAD(&priv->maps);
INIT_LIST_HEAD(&priv->freeable_maps);
spin_lock_init(&priv->lock);
mutex_init(&priv->lock);
if (use_ptemod) {
priv->mm = get_task_mm(current);
......@@ -572,10 +572,10 @@ static long gntdev_ioctl_map_grant_ref(struct gntdev_priv *priv,
return -EFAULT;
}
spin_lock(&priv->lock);
mutex_lock(&priv->lock);
gntdev_add_map(priv, map);
op.index = map->index << PAGE_SHIFT;
spin_unlock(&priv->lock);
mutex_unlock(&priv->lock);
if (copy_to_user(u, &op, sizeof(op)) != 0)
return -EFAULT;
......@@ -594,7 +594,7 @@ static long gntdev_ioctl_unmap_grant_ref(struct gntdev_priv *priv,
return -EFAULT;
pr_debug("priv %p, del %d+%d\n", priv, (int)op.index, (int)op.count);
spin_lock(&priv->lock);
mutex_lock(&priv->lock);
map = gntdev_find_map_index(priv, op.index >> PAGE_SHIFT, op.count);
if (map) {
list_del(&map->next);
......@@ -602,7 +602,7 @@ static long gntdev_ioctl_unmap_grant_ref(struct gntdev_priv *priv,
list_add_tail(&map->next, &priv->freeable_maps);
err = 0;
}
spin_unlock(&priv->lock);
mutex_unlock(&priv->lock);
if (map)
gntdev_put_map(priv, map);
return err;
......@@ -670,7 +670,7 @@ static long gntdev_ioctl_notify(struct gntdev_priv *priv, void __user *u)
out_flags = op.action;
out_event = op.event_channel_port;
spin_lock(&priv->lock);
mutex_lock(&priv->lock);
list_for_each_entry(map, &priv->maps, next) {
uint64_t begin = map->index << PAGE_SHIFT;
......@@ -698,7 +698,7 @@ static long gntdev_ioctl_notify(struct gntdev_priv *priv, void __user *u)
rc = 0;
unlock_out:
spin_unlock(&priv->lock);
mutex_unlock(&priv->lock);
/* Drop the reference to the event channel we did not save in the map */
if (out_flags & UNMAP_NOTIFY_SEND_EVENT)
......@@ -748,7 +748,7 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
pr_debug("map %d+%d at %lx (pgoff %lx)\n",
index, count, vma->vm_start, vma->vm_pgoff);
spin_lock(&priv->lock);
mutex_lock(&priv->lock);
map = gntdev_find_map_index(priv, index, count);
if (!map)
goto unlock_out;
......@@ -783,7 +783,7 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
map->flags |= GNTMAP_readonly;
}
spin_unlock(&priv->lock);
mutex_unlock(&priv->lock);
if (use_ptemod) {
err = apply_to_page_range(vma->vm_mm, vma->vm_start,
......@@ -811,11 +811,11 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
return 0;
unlock_out:
spin_unlock(&priv->lock);
mutex_unlock(&priv->lock);
return err;
out_unlock_put:
spin_unlock(&priv->lock);
mutex_unlock(&priv->lock);
out_put_map:
if (use_ptemod)
map->vma = NULL;
......
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