Using SIGNALS in linux kernel modules

shathil · 04-23-2010, 06:23 AM

Hello
I am writing a kernel module which need to do something at some interval. Now this problem can be solved by using a user process, which will send signal to the kernel and the kernel would do accordingly. But it would be nice, i could do it within the kernel module itself. Is there any way to use SIGNALs inside the kernel module?

BR
Mohammad Hoque

Aquarius_Girl · 04-23-2010, 09:01 AM

Hi,

Quote:

a user process, which will send signal to the kernel and the kernel would do accordingly.

AFAIK signals can only be sent from kernel space to user space, not vice-versa.

Quote:

Is there any way to use SIGNALs inside the kernel module?

Explain what exactly you want to achieve when you say that you want to use signals inside kernel module ?

There is a discussion going on here w.r.t sending signals from kernel space to user space:
http://www.linuxquestions.org/questi...rocess-803485/

also see:
http://linux.die.net/man/2/kill

sundialsvcs · 04-23-2010, 10:35 PM

Go with your first idea. (I mean that!)

Use a user-space process. Have it request kernel services when necessary.

"The kernel" is an extremely special-purpose environment. It exists only to support userland processes (privileged or not).

For example: "the kernel is not 'signaled.'" Rather, "the kernel exists to implement the concept of 'signals.' (And for that matter... of 'processes' and 'threads.')" It creates these things: therefore, it does not (and cannot...) live by them.

paulsm4 · 04-24-2010, 03:06 PM

As anishakaul and sundialsvcs both implied:

Quote:

If you *can* do something in user space ... then you usually *should* do it in user space!