Re: [PATCH 1/1] Introduce Intel RAPL cooling device driver

From: Greg KH
Date: Tue Apr 02 2013 - 19:48:14 EST


On Tue, Apr 02, 2013 at 04:33:57PM -0700, Jacob Pan wrote:
> On Tue, 2 Apr 2013 16:00:42 -0700
> Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>
> > > +#include "intel_rapl.h"
> > > +#include "../../../fs/sysfs/sysfs.h"
> >
> > WTF?
> >
> > Oh, that's a sure sign you are not doing something properly, if you
> > think it's ok to muck around with the internals of sysfs.
> >
> > There's a reason that file is "private", why do you think it's ok to
> > use it directly? Did you just think that I somehow "forgot" to put
> > it in the proper include directory?
> I did feel unsure about this but i saw some precedence in the kernel.

Someone else is doing this with the sysfs api? I don't see any other
code in Linus's tree doing this at the moment, where did you see this?
Let me know and I'll fix it up right away.

> Anyway, I needed a way to validate a userspace file passed to rapl
> driver belong to the same sysfs directory. I will look for alternative
> ways.

What do you mean by this? What exactly are you trying to do? No normal
driver code should _ever_ call sysfs functions directly, nor should they
ever care about sysfs internals.

And, odds are, you didn't test your code as a module, right, as any
internal sysfs function that you could get from this .h file, wouldn't
be exported for a module to use, unless I missed one somewhere?

greg k-h
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/