Re: [PATCHv4] MTD: New ioctl calls for >4GiB device support

[Arnd Bergmann]

On Tuesday 31 March 2009, Kevin Cernekee wrote:
> +struct mtd_oob_buf64 {
> +ÂÂÂÂÂÂÂuint64_t start;
> +ÂÂÂÂÂÂÂuint32_t res0;
> +ÂÂÂÂÂÂÂuint32_t length;
> +ÂÂÂÂÂÂÂunsigned char __user *ptr;
> +ÂÂÂÂÂÂÂuint32_t res1[8];
> +};

Does this have to use an indirect pointer? We normally try to avoid
ioctl interfaces like this, because they are hard to trace and you
need a compat wrapper. You might be able to at least avoid the wrapper
by defining the data structure with a __u64 to take the pointer.

If you leave the data structure the way it is, you should at least
move the compat_ioctl handling into mtdchar.c from compat_ioctl.c.
It will simplify your code and help reduce the size of the common
ioctl handling.

	Arnd <><
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