Re: [PATCH v2 4/5] mm: Add a NO_INHERIT flag to the PR_SET_MDWE prctl

[Florent Revest <revest@xxxxxxxxxxxx>]

On Mon, May 22, 2023 at 11:01 AM David Hildenbrand <david@xxxxxxxxxx> wrote:
>
> On 17.05.23 17:03, Florent Revest wrote:
> > +#define MMF_INIT_FLAGS(flags)        ({                                      \
> > +     unsigned long new_flags = flags;                                \
> > +     if (new_flags & (1UL << MMF_HAS_MDWE_NO_INHERIT))               \
> > +             new_flags &= ~((1UL << MMF_HAS_MDWE) |                  \
> > +                             (1UL << MMF_HAS_MDWE_NO_INHERIT));      \
> > +     new_flags & MMF_INIT_MASK;                                      \
> > +})
>
> Why the desire for macros here? :)

I just thought that's what the cool kids do nowadays ?! :)

Eh, I'm joking, I completely agree. Somehow this was suggested to me
in v1 as a macro and I didn't think of questioning that, but a static
inline function should be more readable indeed! I will fix this in v3.

> We have a single user of MMF_INIT_FLAGS, why not inline or use a proper
> inline function?

I have a slight preference for a separate function, so we don't spill
over too much of this logic in fork.c.

Thanks for the review David!