If the resource is located in kernel, it should be guarded by kernel
spinlock, I think. Access operation from userspace must wait with this
spinlock.

If you decribe yor problem more detailed (what is the resource, what are
resource operations from userspace and kernel, for example) other
suggestions may comes.

BTW, preferred language in this forum is Russian, so please forgive me
my terrible English.



zifo wrote:

> I have a resource which must be manipulated through semaphores from user space and from kernel space ... I think the only way is to use a SysV IPC semaphore ...
> but it seems I can't use it from my kernel module .. the kernel doesn't export any of its functions ...