[PATCH v0 42/42] notifier: Return an error when callback is already registered

[Geert Uytterhoeven]

Hi Borislav,

On Mon, Nov 8, 2021 at 4:59 PM Borislav Petkov <bp at alien8.de> wrote:
> On Mon, Nov 08, 2021 at 04:25:47PM +0100, Geert Uytterhoeven wrote:
> > I'm not against returning proper errors codes.  I'm against forcing
> > callers to check things that cannot fail and to add individual error
> > printing to each and every caller.
>
> If you're against checking things at the callers, then the registration
> function should be void. IOW, those APIs are not optimally designed atm.

Returning void is the other extreme ;-)

There are 3 levels (ignoring BUG_ON()/panic () inside the callee):
  1. Return void: no one can check success or failure,
  2. Return an error code: up to the caller to decide,
  3. Return a __must_check error code: every caller must check.

I'm in favor of 2, as there are several places where it cannot fail.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds