diff options
| author | Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> | 2014-08-03 19:59:35 +0900 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-10-05 14:54:07 -0700 |
| commit | 0f90c9c088df9196dbb322175413a79f41f9975f (patch) | |
| tree | c692dfbdf9e50745130e35b6e6799c423c7fb30b /drivers/gpu | |
| parent | ddb3b2c0ed7d2f9b0f429824c096566c38dfda66 (diff) | |
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: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/gpu')
| -rw-r--r-- | drivers/gpu/drm/ttm/ttm_page_alloc_dma.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c index b8b394319b45..e9f65ad2a0eb 100644 --- a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c +++ b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c @@ -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(); |