Re: [PATCH v5 3/6] mm/memfd: add MFD_NOEXEC_SEAL and MFD_EXEC

[Jeff Xu]

On Tue, Dec 6, 2022 at 8:04 AM Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>
> On Tue, Dec 06, 2022 at 03:23:55PM +0000, jeffxu@xxxxxxxxxxxx wrote:
> > --- a/kernel/pid_namespace.c
> > +++ b/kernel/pid_namespace.c
> > @@ -110,6 +110,11 @@ static struct pid_namespace *create_pid_namespace(struct user_namespace *user_ns
> >       ns->ucounts = ucounts;
> >       ns->pid_allocated = PIDNS_ADDING;
> >
> > +#if defined(CONFIG_SYSCTL) && defined(CONFIG_MEMFD_CREATE)
> > +     ns->memfd_noexec_scope =
> > +             task_active_pid_ns(current)->memfd_noexec_scope;
> > +#endif
>
> .c files should never have #if in them.  Can't you put this in a .h file
> properly so that this does not get really messy over time?
>
>
Thanks for reviewing.
It seems to me that checking for CONFIG_XXX is  common in c code in
kernel/ path.
Do you have a sample code pattern (link/function) that I can follow?

Thanks
Jeff

>
> > +
> >       return ns;
> >
> >  out_free_idr:
> > @@ -255,6 +260,45 @@ void zap_pid_ns_processes(struct pid_namespace *pid_ns)
> >       return;
> >  }
> >
> > +#if defined(CONFIG_SYSCTL) && defined(CONFIG_MEMFD_CREATE)
>
> Same here.
>
> thanks,
>
> greg k-h