[PATCH] mmc: renesas_sdhi: Add missing checks for the presence of quirks

[PATCH] mmc: renesas_sdhi: Add missing checks for the presence of quirks

[Geert Uytterhoeven]

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@glider.be>
---
 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

Re: [PATCH] mmc: renesas_sdhi: Add missing checks for the presence of quirks

[Wolfram Sang]

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On Fri, Apr 01, 2022 at 04:09:28PM +0200, Geert Uytterhoeven 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@glider.be>

Thanks for catching this!

Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>


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Re: [PATCH] mmc: renesas_sdhi: Add missing checks for the presence of quirks

[Ulf Hansson]

On Fri, 1 Apr 2022 at 16:09, Geert Uytterhoeven <geert+renesas@glider.be> 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@glider.be>

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
>