A kernel module that dynamically patches the Linux kernel scheduler so as to allow running a custom function upon thread reschedule This is the schedule-hook kernel module, to allow running a custom function e.g. in another module, upon thread reschedule
This module can be used either in cross compilation with the one containing the custom function or not
This module patches at run-time the kernel schedule() and enables running a schedule-hook function as the last task of thread re-schedule
The schdule-hook function is embedded within this module, it checks the value of a function pointer and in case it is not null the target functio is called
In cross compilation the function pointer is exported as a symbol to be updated while mounting the module containing the custom functions to be run
Otherwise, the function ponter is accessible as a pseudofile called /sys/module/schedule_hook/parameters/the_hook
In the latter configuraiton, after mounting the module, you can load any function pointer you would like (pointing to kernel stuff) by writing it on that pseudofile
The custom function to be run needs to get no paramter in input
Please check with the follosing configuration macros to manage the configuration of this module:
- DEBUG and DEBUG_SCHEDULE_HOOK for enalbing or disabling debugging/audit stuff
- SYS_FS for enabling of disabling the reliance on /sys
NOTE: the custom function is expected to be non-blocking, in case it is blocking the unmount of this module may hang
NOTE: this module shoudl be unmounted before unmounting the one containing the custom function otherwise your kernel wil likely crash
The code has been developed by:
- Francesco Quaglia [email protected]
- Alessandro Pellegrini [email protected]
and is Copyright (C) 2015 HPDCS Group, http://www.dis.uniroma1.it/~hpdcs
For installation and usage information, please refer to INSTALL.