Date: Thu, 17 Mar 2005 13:49:03 -0800 From: John-Mark Gurney <gurney_j@resnet.uoregon.edu> To: Aziz KEZZOU <opensource.enthousiat@gmail.com> Cc: freebsd-hackers@freebsd.org Subject: Re: How to send a signal from inside the kernel? Message-ID: <20050317214903.GL89312@funkthat.com> In-Reply-To: <37e1316605031711555c47c8ca@mail.gmail.com> References: <37e13166050317093477de8f7a@mail.gmail.com> <20050317181200.GK89312@funkthat.com> <37e1316605031711555c47c8ca@mail.gmail.com>
next in thread | previous in thread | raw e-mail | index | archive | help
Aziz KEZZOU wrote this message on Thu, Mar 17, 2005 at 14:55 -0500:
> > Aziz KEZZOU wrote this message on Thu, Mar 17, 2005 at 12:34 -0500:
> > > Hi all,
> > > I would like to send a signal (e.g SIGUSR1) to a user process from
> > > inside the kernel (kld module).
> > > Can any one tell me how to do it ?
> > > I tried the following code inspired from sys/kern/kern_sig.c :
> > > ==============================================================
> > > #include <sys/types.h>
> > > #include <sys/signal.h>
> > >
> > > int process_pid;
> > > struct kill_args {
> > > int pid;
> > > int signum;
> > > };
> > >
> > > void send_SIGUSR1() {
> > > struct kill_args uap;
> > > uap.pid = process_pid;
> > > uap.signum = SIGUSR1;
> > > kill((struct thread *)0, &uap);
> > > }
> > > ===============================================================
> > >
> > > but that causes a page fault in kernel mode (ie. Kernel panic :-)
> > >
> > > Any help is appreciated, thanks.
> >
> > Take a look at psignal(9)... You'll need to look up the struct proc
> > for psignal with pfind(9)... and then PROC_UNLOCK the struct proc
> > after you've used psignal...
> >
> > so:
> > struct proc *p;
> >
> > p = pfind(pid);
> > if (p != NULL) {
> > psignal(p, SIGUSR1);
> > PROC_UNLOCK(p);
> > }
> >
> > I haven't tried the code above, but that should do what you want...
>
> It works, thanks a lot !!
> Here are the headers needed in case someone reads this thread:
>
> #include <unistd.h> /*needed only for NULL, can be removed*/
This header (unistd.h) shouldn't be included in kernel code...
> #include <sys/types.h>
> #include <sys/param.h>
style(9) says:
Kernel include files (i.e. sys/*.h) come first; normally, include
<sys/types.h> OR <sys/param.h>, but not both.
It also looks like sys/param.h is suppose to define NULL since it
includes _null.h (on -current) or defines it directly (on RELENG_4)...
so you could should just include sys/param.h, and ditch sys/types.h
and unistd.h and it should work...
> #include <sys/lock.h>
> #include <sys/mutex.h>
> #include <sys/proc.h>
--
John-Mark Gurney Voice: +1 415 225 5579
"All that I will do, has been done, All that I have, has not."
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20050317214903.GL89312>