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From:   Tomasz Figa <tfiga@chromium.org>
Date:   Thu, 12 Oct 2023 15:19:19 +0900
Message-ID: <CAAFQd5AgK0ZmOABxnvtUHLJ7nPzPL7cZp_ezUifpSJWEDVFHWQ@mail.gmail.com>
Subject: Re: [PATCH] media: videobuf2: Fix IS_ERR checking in vb2_dc_put_userptr()
To:     Ma Ke <make_ruc2021@163.com>
Cc:     m.szyprowski@samsung.com, mchehab@kernel.org,
        linux-media@vger.kernel.org, linux-kernel@vger.kernel.org
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On Tue, Oct 3, 2023 at 6:23=E2=80=AFPM Ma Ke <make_ruc2021@163.com> wrote:
>
> In order to avoid error pointers from frame_vector_pages(), we could
> use IS_ERR() to check the return value to fix this. This checking
> operation could make sure that vector contains pages.
>
> Signed-off-by: Ma Ke <make_ruc2021@163.com>
> ---
>  .../media/common/videobuf2/videobuf2-dma-contig.c   | 13 +++++++------
>  1 file changed, 7 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/media/common/videobuf2/videobuf2-dma-contig.c b/driv=
ers/media/common/videobuf2/videobuf2-dma-contig.c
> index 2fa455d4a048..5001f2a258dd 100644
> --- a/drivers/media/common/videobuf2/videobuf2-dma-contig.c
> +++ b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
> @@ -542,13 +542,14 @@ static void vb2_dc_put_userptr(void *buf_priv)
>                  */
>                 dma_unmap_sgtable(buf->dev, sgt, buf->dma_dir,
>                                   DMA_ATTR_SKIP_CPU_SYNC);
> -               pages =3D frame_vector_pages(buf->vec);
> -               /* sgt should exist only if vector contains pages... */
> -               BUG_ON(IS_ERR(pages));
>                 if (buf->dma_dir =3D=3D DMA_FROM_DEVICE ||
> -                   buf->dma_dir =3D=3D DMA_BIDIRECTIONAL)
> -                       for (i =3D 0; i < frame_vector_count(buf->vec); i=
++)
> -                               set_page_dirty_lock(pages[i]);
> +                   buf->dma_dir =3D=3D DMA_BIDIRECTIONAL){

Missing space between ) and { .

Otherwise:

Acked-by: Tomasz Figa <tfiga@chromium.org>

Best regards,
Tomasz

> +                       pages =3D frame_vector_pages(buf->vec);
> +                       /* sgt should exist only if vector contains pages=
... */
> +                       if (!WARN_ON_ONCE(IS_ERR(pages)))
> +                               for (i =3D 0; i < frame_vector_count(buf-=
>vec); i++)
> +                                       set_page_dirty_lock(pages[i]);
> +               }
>                 sg_free_table(sgt);
>                 kfree(sgt);
>         } else {
> --
> 2.37.2
>