Re: [PATCH v4] dma-buf: system_heap: Use 'for_each_sgtable_sg' in pages free flow

[John Stultz]

On Thu, Nov 25, 2021 at 11:48 PM <guangming.cao@xxxxxxxxxxxx> wrote:
>
> From: Guangming <Guangming.Cao@xxxxxxxxxxxx>
>
> 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@xxxxxxxxxxxx>
> Reviewed-by: Robin Murphy <robin.murphy@xxxxxxx>
> Cc: <stable@xxxxxxxxxxxxxxx> # 5.11.*

Thanks so much for catching this and sending in all the revisions!

Reviewed-by: John Stultz <john.stultz@xxxxxxxxxx>