Capture hrtimer interrupts with linux kernel module .. possible?

Question

I would like to be able to 'capture' an hrtimer interrupt with a linux kernel module and replay the interrupt at a later period in time. Any thoughts on how to go about doing this?

Use case: A program that calls sleep(1). My module will grab the hrtimer interrupt when it fires after 1 second, wait for 'x' amount of time, then re-fire the interrupt, waking the process.

Note: I do not want to hook the sleep system call.

Thanks!

Answer 1

Quite honestly, writing a Linux kernel module just to modify the behavior of sleep() for a single application sounds like overkill.

For most cases you should be able to use a preloadable shared object to intercept/override the sleep() function family with your own implementations. The application will call your implementation and your code may then call the real function with a modified parameter list.

This method is much simpler and less intrusive than anything involving kernel programming, although it will not work if your application is statically linked or if it uses direct system calls instead of library functions.