Handling alarm signal in system call implementation

[samarf]

I am trying to implement a system call in linux that performs a specifc functionality after some seconds have elapsed. For this pupose i use sys_alarm() in my system call and pass to it the number of seconds i want the process to wait. When the alarm goes off i call a handler function that is registered using sys_signal(). The problem is that whenever i invoke the system call through a user program, the user program gets stuck...Could you please go through the code and check what is missing ?

#include <linux/linkage.h> //for linking a system call
#include <linux/kernel.h>
#include<linux/reboot.h>
#include<linux/sched.h>
#include<linux/time.h>
#include<linux/signal.h>
#include<linux/unistd.h>
#include<linux/syscalls.h>


volatile int keep_going = 1;

void alarm_handler(int signal)
{
keep_going = 0;

}

asmlinkage long sys_myservice(int arg) {

int delay=20;
sys_signal(SIGALRM, alarm_handler);
sys_alarm(20);

while (keep_going){

//do nothing
}

//write functionality here


return 1;

}

[Rubberman]

What do you mean by "whenever i invoke the system call through a user program"? Are you trying to invoke the call directly? Have you written and installed a kernel module to handle the call from the user?