From: Zhang Qiang <qiang.zhang@xxxxxxxxxxxxx>
When traversing "pool->page" linked list, to prevent possible
other path operations this list, causing it to be destroyed, we
should add lock protect for this list in dma_pool_destroy func.
Signed-off-by: Zhang Qiang <qiang.zhang@xxxxxxxxxxxxx>
---
mm/dmapool.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/mm/dmapool.c b/mm/dmapool.c
index f9fb9bbd733e..f7375b25af6c 100644
--- a/mm/dmapool.c
+++ b/mm/dmapool.c
@@ -267,6 +267,9 @@ static void pool_free_page(struct dma_pool *pool, struct dma_page *page)
void dma_pool_destroy(struct dma_pool *pool)
{
bool empty = false;
+ LIST_HEAD(discard);
+ struct dma_page *page,*h;
+ unsigned long flags;
if (unlikely(!pool))
return;
@@ -281,8 +284,8 @@ void dma_pool_destroy(struct dma_pool *pool)
device_remove_file(pool->dev, &dev_attr_pools);
mutex_unlock(&pools_reg_lock);
+ spin_lock_irqsave(&pool->lock, flags);
while (!list_empty(&pool->page_list)) {
- struct dma_page *page;
page = list_entry(pool->page_list.next,
struct dma_page, page_list);
if (is_page_busy(page)) {
@@ -297,8 +300,12 @@ void dma_pool_destroy(struct dma_pool *pool)
list_del(&page->page_list);
kfree(page);
} else
- pool_free_page(pool, page);
+ list_move(&page->page_list, &discard);
}
+ spin_unlock_irqrestore(&pool->lock, flags);
+
+ list_for_each_entry_safe(page, h, &discard, page_list)
+ pool_free_page(pool, page);
kfree(pool);
}
--
2.26.2
