On Tue, May 2, 2017 at 1:15 PM, Simon Horman <horms+renesas@xxxxxxxxxxxx> wrote:
> @@ -202,6 +214,15 @@ void tmio_mmc_enable_mmc_irqs(struct tmio_mmc_host *host, u32 i);
> void tmio_mmc_disable_mmc_irqs(struct tmio_mmc_host *host, u32 i);
> irqreturn_t tmio_mmc_irq(int irq, void *devid);
>
> +#if IS_ENABLED(CONFIG_MMC_SDHI)
> +const struct tmio_mmc_dma_ops *tmio_mmc_get_dma_ops(void);
> +#else
> +static inline const struct tmio_mmc_dma_ops *tmio_mmc_get_dma_ops(void)
> +{
> + return NULL;
> +}
> +#endif
> +
> static inline char *tmio_mmc_kmap_atomic(struct scatterlist *sg,
> unsigned long *flags)
> {
Here you return a NULL pointer for the operations structure
> +
> +static inline void tmio_mmc_enable_dma(struct tmio_mmc_host *host, bool enable)
> +{
> + if (host->dma_ops->enable)
> + host->dma_ops->enable(host, enable);
> +}
>
And here you check the ->enable callback but not the dma_ops pointer.
In the other callbacks you check the dma_ops pointer but not the callback.
Is that intentional? Maybe always check the dma_ops pointer first for
consistency, as a NULL operations structure (resulting from a future bug)
might lead running user space with kernel privileges.
Arnd
