I am working on a kernel module where I need to be "aware" that a given process has crashed.

Right now my approach is to set up a periodic timer interrupt in the kernel module; on every timer interrupt, I check the task_struct.state and task_struct.exitstate values for that process.

I am wondering if there's a way to set up an interrupt in the kernel module that would go off when the process terminates, or, when the process receives a given signal (e.g., SIGINT or SIGHUP).

Thanks!

I think maybe you need to install an Interrupt Handler? <guessing>
http://www.makelinux.net/ldd3/chp-10-sect-2

http://www.tldp.org/LDP/lkmpg/2.4/html/x1210.html

https://www.google.com/search?q=webc...kernel+module+

HTH

Good Luck-

Thank you Ztcorcat; I think the crux would be, what kind of interrupt is available to set up to trigger the interrupt handler - i.e., whether it is possible to set up an interrupt that would fire when a user process receives a signal or terminates.

I has been suggested to me elsewhere to set up a character device and put a signal handler into the process that sends a message to the character device. It has also been suggested to me to use a watchdog timer. But here's another kink: I really don't want to modify the user process code - I don't think my customer would go for that type of solution.

You're Welcome.

Sorry I've never used Watchdog timer.

If your customer doesn't want the process code modified I can see where that could make it difficult for you.

Maybe other members will chime in and know what you could try.

If you don't know what to do than do what you know.-

Another idea that comes to mind is that you could implement the thing as a virtual filesystem. In other words, the client process opens the "file," then uses read/write/ioctl semantics to manipulate it. If the process terminates, all of its file-handles will be closed, thus giving you automatic notification of the event.

Perhaps you could put the monkey on the user-process's back, requiring it to set its own signal-handler and to, say, issue some ioctl() call against the file-handler if the handler goes off.