Re: Sending IOCTLs from 32-bit userland to 64-bit Kernel module

[Jiri Slaby <jirislaby@gmail.com>]

On 01/29/2008 02:18 PM, Yoav Artzi wrote:
> Thanks. I am aware of these issues and we already have a pretty capable 
> layer to deal with these issues (unfortunately, it was very necessary). 
> My problem is not with the data carried by the IOCTL, but with IOCTL 
> command code itself, which comes out wrong on the kernel side. And my 
> problem is not only in the size data, but also in other fields.
> 
> IOCTL command code:
> 
> 1 byte: W/R/RW                                       -------- Passes 
> through fine
> 
> 1 byte: size of data carried                         -------- DOESN'T 
> PASS THROUGH
> 
> 1 byte: identifier character of the module   -------- Passes through fine
> 
> 1 byte: IOCTL number                               -------- DOESN'T PASS 
> THROUGH
> 
> 
> The funny thing is that I always get the same IOCTL command code on the 
> kernel side, no matter what I send using the ioctl() system call.
> 
> 
> Any idea?

Please show us your code with ioctls implemented both in kernel and userspace. 
And the definitions and fops aswell. Without it it's very hard to say what's 
going wrong.