Hi Pravin, > ... > I need to provide a hook from kernel-space to userspace. > ... > ... > I am also looking for possibility for pausing the execution > kernel thread till userspace function acknowlages the data > and take certain action on it. > ... This is not possible. And well, as others may advice, not at all logical. If you really need access to kernel data-structures and you feel your code needs to be called in middle of some kernel code path, a better decision might be to include your code in the kernel space itself. Sitting in the userspace, the closest you can get to it is using call_usermodehelper() that allows you call a userspace binary. Thanks, Rajat -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ