Commit d43eaf1d749b ("virtio: silence KCSAN warning in
virtqueue_kick_prepare") introduced a compile error in
__vringh_notify_enable() because __vringh_notify_enable dereferences the
return of the vring_avail_event() macro making it incompatible with the
data_race() annotation added in d43eaf1d749b.
Remove the data_race() annotation in vring_avail_event() and move it
into it's callers instead.
Fixes: d43eaf1d749b ("virtio: silence KCSAN warning in virtqueue_kick_prepare")
Reported-by: kernel test robot <[email protected]>
Closes:
https://lore.kernel.org/oe-kbuild-all/[email protected]/
Signed-off-by: Johannes Thumshirn <[email protected]>
---
Michael: I wasn't sure if you want a patch on top (what I did) or a new
version of the broken patch to replace it. Just drop me a note if I
should take the other way.
drivers/vhost/vringh.c | 4 ++--
drivers/virtio/virtio_ring.c | 2 +-
include/uapi/linux/virtio_ring.h | 2 +-
3 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/vhost/vringh.c b/drivers/vhost/vringh.c
index 925858cc6096..47d3a8bb9c52 100644
--- a/drivers/vhost/vringh.c
+++ b/drivers/vhost/vringh.c
@@ -556,10 +556,10 @@ static inline bool __vringh_notify_enable(struct vringh
*vrh,
return true;
}
} else {
- if (putu16(vrh, &vring_avail_event(&vrh->vring),
+ if (putu16(vrh, data_race(&vring_avail_event(&vrh->vring)),
vrh->last_avail_idx) != 0) {
vringh_bad("Updating avail event index %p",
- &vring_avail_event(&vrh->vring));
+ data_race(&vring_avail_event(&vrh->vring)));
return true;
}
}
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 1db27ee2d89f..95744d03b284 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -737,7 +737,7 @@ static bool virtqueue_kick_prepare_split(struct virtqueue
*_vq)
if (vq->event) {
needs_kick = vring_need_event(virtio16_to_cpu(_vq->vdev,
- vring_avail_event(&vq->split.vring)),
+
data_race(vring_avail_event(&vq->split.vring))),
new, old);
} else {
needs_kick = !(vq->split.vring.used->flags &
diff --git a/include/uapi/linux/virtio_ring.h b/include/uapi/linux/virtio_ring.h
index 32568cfa1c63..f8c20d3de8da 100644
--- a/include/uapi/linux/virtio_ring.h
+++ b/include/uapi/linux/virtio_ring.h
@@ -194,7 +194,7 @@ struct vring {
/* We publish the used event index at the end of the available ring, and vice
* versa. They are at the end for backwards compatibility. */
#define vring_used_event(vr) ((vr)->avail->ring[(vr)->num])
-#define vring_avail_event(vr) (data_race(*(__virtio16
*)&(vr)->used->ring[(vr)->num]))
+#define vring_avail_event(vr) (*(__virtio16 *)&(vr)->used->ring[(vr)->num])
static inline void vring_init(struct vring *vr, unsigned int num, void *p,
unsigned long align)
--
2.52.0
