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path: root/drivers/xen/gntdev.c
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Diffstat (limited to 'drivers/xen/gntdev.c')
-rw-r--r--drivers/xen/gntdev.c80
1 files changed, 42 insertions, 38 deletions
diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index 84b143eef395..4d9a3050de6a 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -286,6 +286,9 @@ void gntdev_put_map(struct gntdev_priv *priv, struct gntdev_grant_map *map)
*/
}
+ if (use_ptemod && map->notifier_init)
+ mmu_interval_notifier_remove(&map->notifier);
+
if (map->notify.flags & UNMAP_NOTIFY_SEND_EVENT) {
notify_remote_via_evtchn(map->notify.event);
evtchn_put(map->notify.event);
@@ -298,7 +301,7 @@ void gntdev_put_map(struct gntdev_priv *priv, struct gntdev_grant_map *map)
static int find_grant_ptes(pte_t *pte, unsigned long addr, void *data)
{
struct gntdev_grant_map *map = data;
- unsigned int pgnr = (addr - map->vma->vm_start) >> PAGE_SHIFT;
+ unsigned int pgnr = (addr - map->pages_vm_start) >> PAGE_SHIFT;
int flags = map->flags | GNTMAP_application_map | GNTMAP_contains_pte |
(1 << _GNTMAP_guest_avail0);
u64 pte_maddr;
@@ -367,8 +370,7 @@ int gntdev_map_grant_pages(struct gntdev_grant_map *map)
for (i = 0; i < map->count; i++) {
if (map->map_ops[i].status == GNTST_okay) {
map->unmap_ops[i].handle = map->map_ops[i].handle;
- if (!use_ptemod)
- alloced++;
+ alloced++;
} else if (!err)
err = -EINVAL;
@@ -377,8 +379,7 @@ int gntdev_map_grant_pages(struct gntdev_grant_map *map)
if (use_ptemod) {
if (map->kmap_ops[i].status == GNTST_okay) {
- if (map->map_ops[i].status == GNTST_okay)
- alloced++;
+ alloced++;
map->kunmap_ops[i].handle = map->kmap_ops[i].handle;
} else if (!err)
err = -EINVAL;
@@ -394,8 +395,14 @@ static void __unmap_grant_pages_done(int result,
unsigned int i;
struct gntdev_grant_map *map = data->data;
unsigned int offset = data->unmap_ops - map->unmap_ops;
+ int successful_unmaps = 0;
+ int live_grants;
for (i = 0; i < data->count; i++) {
+ if (map->unmap_ops[offset + i].status == GNTST_okay &&
+ map->unmap_ops[offset + i].handle != INVALID_GRANT_HANDLE)
+ successful_unmaps++;
+
WARN_ON(map->unmap_ops[offset + i].status != GNTST_okay &&
map->unmap_ops[offset + i].handle != INVALID_GRANT_HANDLE);
pr_debug("unmap handle=%d st=%d\n",
@@ -403,6 +410,10 @@ static void __unmap_grant_pages_done(int result,
map->unmap_ops[offset+i].status);
map->unmap_ops[offset+i].handle = INVALID_GRANT_HANDLE;
if (use_ptemod) {
+ if (map->kunmap_ops[offset + i].status == GNTST_okay &&
+ map->kunmap_ops[offset + i].handle != INVALID_GRANT_HANDLE)
+ successful_unmaps++;
+
WARN_ON(map->kunmap_ops[offset + i].status != GNTST_okay &&
map->kunmap_ops[offset + i].handle != INVALID_GRANT_HANDLE);
pr_debug("kunmap handle=%u st=%d\n",
@@ -411,11 +422,15 @@ static void __unmap_grant_pages_done(int result,
map->kunmap_ops[offset+i].handle = INVALID_GRANT_HANDLE;
}
}
+
/*
* Decrease the live-grant counter. This must happen after the loop to
* prevent premature reuse of the grants by gnttab_mmap().
*/
- atomic_sub(data->count, &map->live_grants);
+ live_grants = atomic_sub_return(successful_unmaps, &map->live_grants);
+ if (WARN_ON(live_grants < 0))
+ pr_err("%s: live_grants became negative (%d) after unmapping %d pages!\n",
+ __func__, live_grants, successful_unmaps);
/* Release reference taken by __unmap_grant_pages */
gntdev_put_map(NULL, map);
@@ -496,11 +511,7 @@ static void gntdev_vma_close(struct vm_area_struct *vma)
struct gntdev_priv *priv = file->private_data;
pr_debug("gntdev_vma_close %p\n", vma);
- if (use_ptemod) {
- WARN_ON(map->vma != vma);
- mmu_interval_notifier_remove(&map->notifier);
- map->vma = NULL;
- }
+
vma->vm_private_data = NULL;
gntdev_put_map(priv, map);
}
@@ -528,29 +539,30 @@ static bool gntdev_invalidate(struct mmu_interval_notifier *mn,
struct gntdev_grant_map *map =
container_of(mn, struct gntdev_grant_map, notifier);
unsigned long mstart, mend;
+ unsigned long map_start, map_end;
if (!mmu_notifier_range_blockable(range))
return false;
+ map_start = map->pages_vm_start;
+ map_end = map->pages_vm_start + (map->count << PAGE_SHIFT);
+
/*
* If the VMA is split or otherwise changed the notifier is not
* updated, but we don't want to process VA's outside the modified
* VMA. FIXME: It would be much more understandable to just prevent
* modifying the VMA in the first place.
*/
- if (map->vma->vm_start >= range->end ||
- map->vma->vm_end <= range->start)
+ if (map_start >= range->end || map_end <= range->start)
return true;
- mstart = max(range->start, map->vma->vm_start);
- mend = min(range->end, map->vma->vm_end);
+ mstart = max(range->start, map_start);
+ mend = min(range->end, map_end);
pr_debug("map %d+%d (%lx %lx), range %lx %lx, mrange %lx %lx\n",
- map->index, map->count,
- map->vma->vm_start, map->vma->vm_end,
- range->start, range->end, mstart, mend);
- unmap_grant_pages(map,
- (mstart - map->vma->vm_start) >> PAGE_SHIFT,
- (mend - mstart) >> PAGE_SHIFT);
+ map->index, map->count, map_start, map_end,
+ range->start, range->end, mstart, mend);
+ unmap_grant_pages(map, (mstart - map_start) >> PAGE_SHIFT,
+ (mend - mstart) >> PAGE_SHIFT);
return true;
}
@@ -1030,18 +1042,15 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
return -EINVAL;
pr_debug("map %d+%d at %lx (pgoff %lx)\n",
- index, count, vma->vm_start, vma->vm_pgoff);
+ index, count, vma->vm_start, vma->vm_pgoff);
mutex_lock(&priv->lock);
map = gntdev_find_map_index(priv, index, count);
if (!map)
goto unlock_out;
- if (use_ptemod && map->vma)
+ if (!atomic_add_unless(&map->in_use, 1, 1))
goto unlock_out;
- if (atomic_read(&map->live_grants)) {
- err = -EAGAIN;
- goto unlock_out;
- }
+
refcount_inc(&map->users);
vma->vm_ops = &gntdev_vmops;
@@ -1062,15 +1071,16 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
map->flags |= GNTMAP_readonly;
}
+ map->pages_vm_start = vma->vm_start;
+
if (use_ptemod) {
- map->vma = vma;
err = mmu_interval_notifier_insert_locked(
&map->notifier, vma->vm_mm, vma->vm_start,
vma->vm_end - vma->vm_start, &gntdev_mmu_ops);
- if (err) {
- map->vma = NULL;
+ if (err)
goto out_unlock_put;
- }
+
+ map->notifier_init = true;
}
mutex_unlock(&priv->lock);
@@ -1087,7 +1097,6 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
*/
mmu_interval_read_begin(&map->notifier);
- map->pages_vm_start = vma->vm_start;
err = apply_to_page_range(vma->vm_mm, vma->vm_start,
vma->vm_end - vma->vm_start,
find_grant_ptes, map);
@@ -1116,13 +1125,8 @@ unlock_out:
out_unlock_put:
mutex_unlock(&priv->lock);
out_put_map:
- if (use_ptemod) {
+ if (use_ptemod)
unmap_grant_pages(map, 0, map->count);
- if (map->vma) {
- mmu_interval_notifier_remove(&map->notifier);
- map->vma = NULL;
- }
- }
gntdev_put_map(priv, map);
return err;
}
generated by cgit v1.2.3 (git 2.39.0) at 2024-07-14 04:09:32 +0300