Whoa!, I did not expect so many replies. Thank you for your answers.
The thing is that the Computer Architecture area of the University I
am studying at is developing a parallel filesystem. Currently it works
as a stand-alone program (this is why it uses resources like
environment variables), and I have been told to integrate it in the
Linux kernel.
I have to justify changes on this filesystem code (like avoiding the
use of environment variables) to my tutor. In this case I needed to
find why it is not possible to use environment variables in kernel
space.
I was looking for a reference documentation which give a definition of
environment variables that exclude their use inside the kernel, or,
simply, I expected to find a design decision to justify this. But I
think I have enough information with your answers, I will be able to
elaborate a satisfactory conclusion.
Excuse me if the topic was so obvious (it was not to me) and thank you again,
On 8/18/05, Linh Dang <[EMAIL PROTECTED]> wrote:
> Douglas McNaught <[EMAIL PROTECTED]> wrote:
>
> >
> > If someone is insisting you use environment varaiables in kernel
> > code, challenge them to show you where they are implemented in the
> > kernel. :)
> >
> > -Doug
>
> They're in current process's vm. You just have to parse it yourself.
>
> something along the (untested) lines:
>
> struct mm_struct *mm = current ? get_task_mm(current) : NULL;
>
> if (mm) {
> unsigned env_len = mm->env_end - mm->env_start;
> char* env = kmalloc(env_len, GFP_KERNEL);
> access_process_vm(current, mm->env_start, env,
> env_len, 0);
>
> /* env is now a big buffer containing null-terminated
> strings representing evironment variables */
>
> mmput(mm);
> }
--
Guillermo
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
