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DateSun, 29 Oct 2006 11:19:53 +0000 (GMT)
Fromranjith kumar <>
SubjectRe: How to run an a.out file in a kernel module
Hi,
    1) What is the synatx of call_usermodehelper()
function?
        I found out that it takes 4 arguments. But
what values  we have to pass as argumets.
I did searched in internet. But could not find out.
Sorry to post this question.

2) How to print something  using C code such that it
will be displayed when corresponding a.out file is
called in a kernel module using call_usermodehelper()
function.

Thanks in advance.

--- Erik Mouw <erik@harddisk-recovery.com> wrote:
> On Fri, Oct 27, 2006 at 11:16:11AM +0100, ranjith
> kumar wrote:
> >           How to run an a.out file in a kernel
> module
> >              I tried to include
> > 
> system("./a.out");
> >      in the C file. But I got compilation errors.
> 
> Simple: you don't. There are a bunch of problems
> over here:
> 
> 1) The system() call is a userland libc call and
> doesn't exist in the
>    kernel
> 2) You can't be sure you're in user context
> 3) You don't know in what filesytem namespace you
> are
> 
> You could use call_usermodehelper() if you really
> need to call a
> usermode helper, but usually it's a sign of bad
> design if you need to.
> 
> 
> Erik
> 
> -- 
> +-- Erik Mouw -- www.harddisk-recovery.com -- +31 70
> 370 12 90 --
> | Lab address: Delftechpark 26, 2628 XH, Delft, The
> Netherlands
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