Re: [PATCH 1/3] rust: implement `kernel::sync::Refcount`

[Dirk Behme]

Am 04.10.24 um 21:08 schrieb Gary Guo:
> On Fri, 04 Oct 2024 20:51:22 +0200
> Andreas Hindborg <a.hindborg@xxxxxxxxxx> wrote:
>
> > Hi Gary,
> >
> > "Gary Guo" <gary@xxxxxxxxxxx> writes:
> >
> > [...]
> >
> > > diff --git a/rust/helpers/refcount.c b/rust/helpers/refcount.c
> > > index f47afc148ec3..39649443426b 100644
> > > --- a/rust/helpers/refcount.c
> > > +++ b/rust/helpers/refcount.c
> > > @@ -8,11 +8,26 @@ refcount_t rust_helper_REFCOUNT_INIT(int n)
> > >   	return (refcount_t)REFCOUNT_INIT(n);
> > >   }
> > >
> > > +unsigned int rust_helper_refcount_read(refcount_t *r)
> > > +{
> > > +	return refcount_read(r);
> > > +}
> >
> > +EXPORT_SYMBOL_GPL(rust_helper_refcount_read);
> >
> > > +
> > > +void rust_helper_refcount_set(refcount_t *r, int n)
> > > +{
> > > +	refcount_set(r, n);
> > > +}
> >
> > +EXPORT_SYMBOL_GPL(rust_helper_refcount_set);
> >
> > BR Andreas
>
> Helper symbol export is automatic after
> e26fa546042a (rust: kbuild: auto generate helper exports)

Yes :)

What results in a question, though:

When to use exports.h and when not?

There are several users of

#include <linux/export.h>

like

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/rust/helpers/err.c
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/rust/helpers/kunit.c
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/rust/helpers/mutex.c

but some don't use it

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/rust/helpers/rbtree.c
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/rust/helpers/uaccess.c

Any rule?

Best regards

Dirk