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authorTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>2014-08-03 19:59:35 +0900
committerDave Airlie <airlied@redhat.com>2014-08-05 10:51:36 +1000
commit11e504cc705e8ccb06ac93a276e11b5e8fee4d40 (patch)
tree7e6feb5fd586ac760f67a319ce19d3c9e9e9883c /drivers/gpu/drm/ttm
parent74cd62ea46f19c41ef20a85792414973ba629cde (diff)
drm/ttm: Fix possible division by 0 in ttm_dma_pool_shrink_scan().
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> Cc: stable <stable@kernel.org> [3.3+] Signed-off-by: Dave Airlie <airlied@redhat.com>
Diffstat (limited to 'drivers/gpu/drm/ttm')
-rw-r--r--drivers/gpu/drm/ttm/ttm_page_alloc_dma.c3
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 fb8259f69839..b751ffffdf0b 100644
--- a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
+++ b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
@@ -1015,6 +1015,8 @@ 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;
@@ -1034,6 +1036,7 @@ 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;
}