On Fri, Nov 26, 2021 at 11:16:05AM +0800, guangming.cao@mediatek.com wrote:

From: Guangming Guangming.Cao@mediatek.com

For previous version, it uses 'sg_table.nent's to traverse sg_table in pages free flow. However, 'sg_table.nents' is reassigned in 'dma_map_sg', it means the number of created entries in the DMA adderess space. So, use 'sg_table.nents' in pages free flow will case some pages can't be freed.

Here we should use sg_table.orig_nents to free pages memory, but use the sgtable helper 'for each_sgtable_sg'(, instead of the previous rather common helper 'for_each_sg' which maybe cause memory leak) is much better.

Fixes: d963ab0f15fb0 ("dma-buf: system_heap: Allocate higher order pages if available")

Signed-off-by: Guangming Guangming.Cao@mediatek.com

drivers/dma-buf/heaps/system_heap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/dma-buf/heaps/system_heap.c b/drivers/dma-buf/heaps/system_heap.c index 23a7e74ef966..8660508f3684 100644 --- a/drivers/dma-buf/heaps/system_heap.c +++ b/drivers/dma-buf/heaps/system_heap.c @@ -289,7 +289,7 @@ static void system_heap_dma_buf_release(struct dma_buf *dmabuf) int i; table = &buffer->sg_table;

• for_each_sg(table->sgl, sg, table->nents, i) {

• for_each_sgtable_sg(table, sg, i) { struct page *page = sg_page(sg);

__free_pages(page, compound_order(page)); -- 2.17.1

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This is not the correct way to submit patches for inclusion in the stable kernel tree. Please read: https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html for how to do this properly.

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