I think, guarding your file operations (read/write/ioctl) with spinlock
in your module should solve the problem. It doesn't matter from where
the file is accessed -- from userspace or from other driver.

wrote:

> Actually, resource is an ordinary node file (file located in /dev directory). There can be processes which open and manipulate the mentioned file and drivers which do the same thing, but at every moment only one module (read driver or process) can work with it. So, I must synchronize this process ...
> Is there any way to synchronize the same resource from kernel space and user space ?