From: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> This patch has been added to the 3.12 stable tree. If you have any objections, please let us know. =============== 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@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Dave Airlie <airlied@xxxxxxxxxx> Signed-off-by: Jiri Slaby <jslaby@xxxxxxx> --- drivers/gpu/drm/ttm/ttm_page_alloc_dma.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c index 7957beeeaf73..eeb8527aba90 100644 --- a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c +++ b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c @@ -1014,6 +1014,8 @@ ttm_dma_pool_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) return SHRINK_STOP; 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 @@ ttm_dma_pool_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) p->pool->dev_name, p->pool->name, current->pid, nr_free, shrink_pages); } +out: mutex_unlock(&_manager->lock); return freed; } -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html