On Fri, 1 Apr 2022 at 16:09, Geert Uytterhoeven <geert+renesas@xxxxxxxxx> wrote:
>
> When running on an system without any quirks (e.g. R-Car V3U), the
> kernel crashes with a NULL pointer dereference:
>
> Unable to handle kernel NULL pointer dereference at virtual address 0000000000000002
> ...
> Hardware name: Renesas Falcon CPU and Breakout boards based on r8a779a0 (DT)
> Workqueue: events_freezable mmc_rescan
> ...
> Call trace:
> renesas_sdhi_internal_dmac_start_dma+0x54/0x12c
> tmio_process_mrq+0x124/0x274
>
> Fix this by adding the missing checks for the validatity of the
> priv->quirks pointer.
>
> Fixes: dce2ba8b2ee8cef6 ("mmc: renesas_sdhi: make 'dmac_only_one_rx' a quirk")
> Fixes: d4bfa17a655c6de2 ("mmc: renesas_sdhi: make 'fixed_addr_mode' a quirk")
> Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Applied for next, thanks!
Kind regards
Uffe
> ---
> drivers/mmc/host/renesas_sdhi_internal_dmac.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mmc/host/renesas_sdhi_internal_dmac.c b/drivers/mmc/host/renesas_sdhi_internal_dmac.c
> index 6dd5ade3851b2ba8..90048f74e6221add 100644
> --- a/drivers/mmc/host/renesas_sdhi_internal_dmac.c
> +++ b/drivers/mmc/host/renesas_sdhi_internal_dmac.c
> @@ -374,7 +374,7 @@ renesas_sdhi_internal_dmac_start_dma(struct tmio_mmc_host *host,
> struct scatterlist *sg = host->sg_ptr;
> u32 dtran_mode = DTRAN_MODE_BUS_WIDTH;
>
> - if (!priv->quirks->fixed_addr_mode)
> + if (!(priv->quirks && priv->quirks->fixed_addr_mode))
> dtran_mode |= DTRAN_MODE_ADDR_MODE;
>
> if (!renesas_sdhi_internal_dmac_map(host, data, COOKIE_MAPPED))
> @@ -382,7 +382,7 @@ renesas_sdhi_internal_dmac_start_dma(struct tmio_mmc_host *host,
>
> if (data->flags & MMC_DATA_READ) {
> dtran_mode |= DTRAN_MODE_CH_NUM_CH1;
> - if (priv->quirks->dma_one_rx_only &&
> + if (priv->quirks && priv->quirks->dma_one_rx_only &&
> test_and_set_bit(SDHI_INTERNAL_DMAC_RX_IN_USE, &global_flags))
> goto force_pio_with_unmap;
> } else {
> --
> 2.25.1
>
