[PATCH] iommufd/driver: Fix counter initialization for counted_by annotation

["Gustavo A. R. Silva" <gustavoars@kernel.org>]

One of the requirements for counted_by annotations is that the counter
member must be initialized before the first reference to the
flexible-array member.

Move the vevent->data_len = data_len; initialization to before the
first access to flexible array vevent->event_data.

Cc: stable@vger.kernel.org
Fixes: e8e1ef9b77a7 ("iommufd/viommu: Add iommufd_viommu_report_event helper")
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
 drivers/iommu/iommufd/driver.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iommu/iommufd/driver.c b/drivers/iommu/iommufd/driver.c
index 6f1010da221c..21d4a35538f6 100644
--- a/drivers/iommu/iommufd/driver.c
+++ b/drivers/iommu/iommufd/driver.c
@@ -161,8 +161,8 @@ int iommufd_viommu_report_event(struct iommufd_viommu *viommu,
 		vevent = &veventq->lost_events_header;
 		goto out_set_header;
 	}
-	memcpy(vevent->event_data, event_data, data_len);
 	vevent->data_len = data_len;
+	memcpy(vevent->event_data, event_data, data_len);
 	veventq->num_events++;
 
 out_set_header:
-- 
2.43.0