On Wed, Nov 4, 2020 at 7:32 AM Souptick Joarder <jrdr.linux@xxxxxxxxx> wrote:
>
> Inside alloc_user_pages() based on flag value either pin_user_pages()
> or get_user_pages_fast() will be called. However, these API might fail.
>
> But free_user_pages() called in error handling path doesn't bother
> about return value and will try to unpin bo->pgnr pages, which is
> incorrect.
>
> Fix this by passing the page_nr to free_user_pages(). If page_nr > 0
> pages will be unpinned based on bo->mem_type. This will also take care
> of non error handling path.
>
> Fixes: 14a638ab96c5 ("media: atomisp: use pin_user_pages() for memory
> allocation")
> Signed-off-by: Souptick Joarder <jrdr.linux@xxxxxxxxx>
> Reviewed-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> Cc: John Hubbard <jhubbard@xxxxxxxxxx>
> Cc: Ira Weiny <ira.weiny@xxxxxxxxx>
> Cc: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> ---
> v2:
> Added review tag.
Any further comment ? If no, can we get this patch in queue for 5.11 ?
>
> drivers/staging/media/atomisp/pci/hmm/hmm_bo.c | 13 ++++++++-----
> 1 file changed, 8 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/staging/media/atomisp/pci/hmm/hmm_bo.c b/drivers/staging/media/atomisp/pci/hmm/hmm_bo.c
> index f13af23..0168f98 100644
> --- a/drivers/staging/media/atomisp/pci/hmm/hmm_bo.c
> +++ b/drivers/staging/media/atomisp/pci/hmm/hmm_bo.c
> @@ -857,16 +857,17 @@ static void free_private_pages(struct hmm_buffer_object *bo,
> kfree(bo->page_obj);
> }
>
> -static void free_user_pages(struct hmm_buffer_object *bo)
> +static void free_user_pages(struct hmm_buffer_object *bo,
> + unsigned int page_nr)
> {
> int i;
>
> hmm_mem_stat.usr_size -= bo->pgnr;
>
> if (bo->mem_type == HMM_BO_MEM_TYPE_PFN) {
> - unpin_user_pages(bo->pages, bo->pgnr);
> + unpin_user_pages(bo->pages, page_nr);
> } else {
> - for (i = 0; i < bo->pgnr; i++)
> + for (i = 0; i < page_nr; i++)
> put_page(bo->pages[i]);
> }
> kfree(bo->pages);
> @@ -942,6 +943,8 @@ static int alloc_user_pages(struct hmm_buffer_object *bo,
> dev_err(atomisp_dev,
> "get_user_pages err: bo->pgnr = %d, pgnr actually pinned = %d.\n",
> bo->pgnr, page_nr);
> + if (page_nr < 0)
> + page_nr = 0;
> goto out_of_mem;
> }
>
> @@ -954,7 +957,7 @@ static int alloc_user_pages(struct hmm_buffer_object *bo,
>
> out_of_mem:
>
> - free_user_pages(bo);
> + free_user_pages(bo, page_nr);
>
> return -ENOMEM;
> }
> @@ -1037,7 +1040,7 @@ void hmm_bo_free_pages(struct hmm_buffer_object *bo)
> if (bo->type == HMM_BO_PRIVATE)
> free_private_pages(bo, &dynamic_pool, &reserved_pool);
> else if (bo->type == HMM_BO_USER)
> - free_user_pages(bo);
> + free_user_pages(bo, bo->pgnr);
> else
> dev_err(atomisp_dev, "invalid buffer type.\n");
> mutex_unlock(&bo->mutex);
> --
> 1.9.1
>
