Kernel drivers and IOCTLs

[Greg KH]

On Tue, Jan 21, 2020 at 10:27:01PM -0600, WyoFlippa wrote:
> Hi,
> 
> I'm working on a driver that would verify a Linux or U-Boot image is secure
> and I need to pass parameters such as the public key, starting address, etc.
> I'd heard in talking to developers that IOCTLs are frowned upon. I also
> found this article that seems to indicate that using sysfs or proc is a
> better way to go.
> 
> https://www.linuxjournal.com/article/8110
> 
> 
> but then I see this article from 2013 which is more recent than the article.
> 
> https://www.kernel.org/doc/html/latest/process/botching-up-ioctls.html
> 
> 
> So are IOCTLs discouraged or not?

They are discouraged, except when they are necessary :)

It all depends on exactly what you are trying to do.

greg k-h