On Tue, Apr 04, 2006 at 18:55:58 +0530, taha hafeez wrote:
> On Mon, 2006-04-03 at 00:26 +0200, Vincenzo Mallozzi wrote:
> > --- taha siddiqi <tawushafeez@xxxxxxxxx> wrote:
> >
> > > Hi
> > >
> > > Same answer, "please explain the situation !!"
> > >
> > > taha
> > >
> > > Thanks.
> >
> > The array I want to pass from kernel space to user
> > space contains pid_t elements.
> > First, I pass the length of the array from user space
> > to kernel space.
> > Then, I build the array with the given length filling
> > it with the pid of processes I need to monitor.
> > Finally, I've to pass this array of pids to the user
> > space.
> > I hope I've well explained the situation.
> > Thanks all.
> > Vincenzo Mallozzi.
> >
>
> Well, I think I get you now....
>
> Correct me if I am wrong...
>
>
> data buffer
> USER_SPACE ------------> KERNEL SPACE [fill data with pid_t]
> ^ |
> | |
> *------<----------------*
> data buffer
>
> Why do we need to pass the data buffer to kernel ?
> Does it contain any information that kernel needs ?
> if not, then that step can be avoided ?
>
> Then you just need a read call implementation of
> struct file_operations {}.
read call implements passing data FROM KERNEL (because it implements the
read syscall)
write call implements passing data TO KERNEL (because it implements the
write syscall)
> taha
>
>
>
>
> --
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>
--
Jan 'Bulb' Hudec <bulb@xxxxxx>
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