[alsa-devel] [PATCH 28/44] fireworks: Add command/response functionality into hwdep interface

[Clemens Ladisch]

Takashi Sakamoto wrote:
> +++ b/include/uapi/sound/firewire.h
>  #define SNDRV_FIREWIRE_EVENT_LOCK_STATUS	0x000010cc
>  #define SNDRV_FIREWIRE_EVENT_DICE_NOTIFICATION	0xd1ce004e
> +#define SNDRV_FIREWIRE_EVENT_EFW_RESPONSE	0x4e617475

Why "Natu"?  ;-)

> +/* each field should be in big endian */
> +struct snd_efw_transaction {
> +	uint32_t length;
> +	uint32_t version;
> +	uint32_t seqnum;
> +	uint32_t category;
> +	uint32_t command;
> +	uint32_t status;
> +	uint32_t params[0];
> +};

uint32_t is not guaranteed to be available in a userspace header.
Add <linux/types.h>, and use __u32.

> +++ b/sound/firewire/fireworks/fireworks.c
>  static int index[SNDRV_CARDS]	= SNDRV_DEFAULT_IDX;
>  static char *id[SNDRV_CARDS]	= SNDRV_DEFAULT_STR;
>  static bool enable[SNDRV_CARDS]	= SNDRV_DEFAULT_ENABLE_PNP;
> +unsigned int resp_buf_size	= 1024;
> +bool resp_buf_debug		= false;

When the driver is compiled into the kernel, these variable names could
introduce conflicts.  Use a prefix like "efw_" or "fireworks_"; the
parameter names can then be made pretty by using module_param_named().

> +static long
> +hwdep_write(struct snd_hwdep *hwdep, const char __user *data, long count,
> +	    loff_t *offset)
> +{
> +	...
> +	if (count < sizeof(struct snd_efw_transaction))
> +		return -EINVAL;

The size must not be larger than allowed for a single write transaction.
This would eventually be caught by the firewire core, but checking it
here would avoid allocating lots of memory.


Regards,
Clemens