Am Donnerstag, den 11.01.2018, 11:54 +0100 schrieb Christian König:
> Yeah, somehow missed that one.
>
> The patch looks mostly good, except for reservation_object_get_excl().
>
> For that one an RCU protection is usually sufficient, so annotating it
> with reservation_object_assert_held() sounds incorrect to me.
Ah, you are correct. I was confused about this one as
reservation_object_get_excl_rcu() exists and and the doc
above reservation_object_get_excl() states "The obj->lock must be
held.", which is misleading for the read-only case.
I'll send a v2 with that fixed.
Regards,
Lucas
> Regards,
> Christian.
>
> Am 11.01.2018 um 11:43 schrieb Lucas Stach:
> > Did this fall through the cracks over the holidays? It really has made
> > my work much easier while reworking some of the reservation object
> > handling in etnaviv and I think it might benefit others.
> >
> > Regards,
> > Lucas
> >
> > Am Freitag, den 01.12.2017, 12:12 +0100 schrieb Lucas Stach:
> > > This adds lockdep asserts to the reservation functions which state in their
> > > documentation that obj->lock must be held. Allows builds with PROVE_LOCKING
> > > enabled to check that the locking requirements are met.
> > >
> > > > Signed-off-by: Lucas Stach <l.stach@xxxxxxxxxxxxxx>
> > >
> > > ---
> > > drivers/dma-buf/reservation.c | 8 ++++++++
> > > include/linux/reservation.h | 2 ++
> > > 2 files changed, 10 insertions(+)
> > >
> > > diff --git a/drivers/dma-buf/reservation.c b/drivers/dma-buf/reservation.c
> > > index b44d9d7db347..accd398e2ea6 100644
> > > --- a/drivers/dma-buf/reservation.c
> > > +++ b/drivers/dma-buf/reservation.c
> > > @@ -71,6 +71,8 @@ int reservation_object_reserve_shared(struct reservation_object *obj)
> > > > > > > > struct reservation_object_list *fobj, *old;
> > > > u32 max;
> > >
> > >
> > > > + reservation_object_assert_held(obj);
> > >
> > > +
> > > > old = reservation_object_get_list(obj);
> > >
> > >
> > > > if (old && old->shared_max) {
> > >
> > > @@ -211,6 +213,8 @@ void reservation_object_add_shared_fence(struct reservation_object *obj,
> > > {
> > > > struct reservation_object_list *old, *fobj = obj->staged;
> > >
> > >
> > > > + reservation_object_assert_held(obj);
> > >
> > > +
> > > > > > > > old = reservation_object_get_list(obj);
> > > > obj->staged = NULL;
> > >
> > >
> > > @@ -236,6 +240,8 @@ void reservation_object_add_excl_fence(struct reservation_object *obj,
> > > > > > > > struct reservation_object_list *old;
> > > > u32 i = 0;
> > >
> > >
> > > > + reservation_object_assert_held(obj);
> > >
> > > +
> > > > > > > > old = reservation_object_get_list(obj);
> > > > > > > > if (old)
> > > > i = old->shared_count;
> > >
> > > @@ -276,6 +282,8 @@ int reservation_object_copy_fences(struct reservation_object *dst,
> > > > > > > > size_t size;
> > > > unsigned i;
> > >
> > >
> > > > + reservation_object_assert_held(dst);
> > >
> > > +
> > > > > > > > rcu_read_lock();
> > > > src_list = rcu_dereference(src->fence);
> > >
> > >
> > > diff --git a/include/linux/reservation.h b/include/linux/reservation.h
> > > index 21fc84d82d41..55e7318800fd 100644
> > > --- a/include/linux/reservation.h
> > > +++ b/include/linux/reservation.h
> > > @@ -212,6 +212,8 @@ reservation_object_unlock(struct reservation_object *obj)
> > > static inline struct dma_fence *
> > > reservation_object_get_excl(struct reservation_object *obj)
> > > {
> > > > + reservation_object_assert_held(obj);
> > >
> > > +
> > > > > > > > return rcu_dereference_protected(obj->fence_excl,
> > > > reservation_object_held(obj));
> > >
> > > }
> >
> > _______________________________________________
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> > dri-devel@xxxxxxxxxxxxxxxxxxxxx
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>
>
