Re: [PATCH] optee: Fix multi page dynamic shm pool alloc

[Jens Wiklander]

Hi Sumit,

On Tue, Nov 19, 2019 at 12:44:26PM +0530, Sumit Garg wrote:
> optee_shm_register() expected pages to be passed as an array of page
> pointers rather than as an array of contiguous pages. So fix that via
> correctly passing pages as per expectation.
> 
> Fixes: a249dd200d03 ("tee: optee: Fix dynamic shm pool allocations")
> Reported-by: Vincent Cao <vincent.t.cao@xxxxxxxxx>
> Signed-off-by: Sumit Garg <sumit.garg@xxxxxxxxxx>
> Tested-by: Vincent Cao <vincent.t.cao@xxxxxxxxx>
> ---
>  drivers/tee/optee/shm_pool.c | 14 +++++++++++++-
>  1 file changed, 13 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/tee/optee/shm_pool.c b/drivers/tee/optee/shm_pool.c
> index 0332a53..85aa5bb 100644
> --- a/drivers/tee/optee/shm_pool.c
> +++ b/drivers/tee/optee/shm_pool.c
> @@ -28,8 +28,20 @@ static int pool_op_alloc(struct tee_shm_pool_mgr *poolm,
>  	shm->size = PAGE_SIZE << order;
>  
>  	if (shm->flags & TEE_SHM_DMA_BUF) {
> +		unsigned int nr_pages = 1 << order, i;
> +		struct page **pages;
> +
> +		pages = kcalloc(nr_pages, sizeof(pages), GFP_KERNEL);
> +		if (!pages)
> +			return -ENOMEM;
> +
> +		for (i = 0; i < nr_pages; i++) {
> +			pages[i] = page;
> +			page++;
> +		}
> +
>  		shm->flags |= TEE_SHM_REGISTER;
> -		rc = optee_shm_register(shm->ctx, shm, &page, 1 << order,
> +		rc = optee_shm_register(shm->ctx, shm, pages, nr_pages,
>  					(unsigned long)shm->kaddr);
>  	}

Apoligies for the later reply. It seems that this will leak memory.
The pointer pages isn't freed after the call to optee_shm_register().

Thanks,
Jens