Commit 0f90c9c0 authored by Tetsuo Handa's avatar Tetsuo Handa Committed by Greg Kroah-Hartman

drm/ttm: Fix possible division by 0 in ttm_dma_pool_shrink_scan().

commit 11e504cc705e8ccb06ac93a276e11b5e8fee4d40 upstream.

list_empty(&_manager->pools) being false before taking _manager->lock
does not guarantee that _manager->npools != 0 after taking _manager->lock
because _manager->npools is updated under _manager->lock.
Signed-off-by: default avatarTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: default avatarDave Airlie <airlied@redhat.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent ddb3b2c0
......@@ -1016,6 +1016,8 @@ static int ttm_dma_pool_mm_shrink(struct shrinker *shrink,
return 0;
mutex_lock(&_manager->lock);
if (!_manager->npools)
goto out;
pool_offset = pool_offset % _manager->npools;
list_for_each_entry(p, &_manager->pools, pools) {
unsigned nr_free;
......@@ -1033,6 +1035,7 @@ static int ttm_dma_pool_mm_shrink(struct shrinker *shrink,
p->pool->dev_name, p->pool->name, current->pid,
nr_free, shrink_pages);
}
out:
mutex_unlock(&_manager->lock);
/* return estimated number of unused pages in pool */
return ttm_dma_pool_get_num_unused_pages();
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment