This patch fixes a bug in put_pasid_state_wait that appeared in kernel 4.0 The bug is that pasid_state->count wasn't decremented before entering the wait_event. Thus, the condition in wait_event will never be true.
The fix is to decrement (atomically) the pasid_state->count before the wait_event. Signed-off-by: Oded Gabbay <[email protected]> Cc: [email protected] --- drivers/iommu/amd_iommu_v2.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/iommu/amd_iommu_v2.c b/drivers/iommu/amd_iommu_v2.c index 6d5a5c4..173e70d 100644 --- a/drivers/iommu/amd_iommu_v2.c +++ b/drivers/iommu/amd_iommu_v2.c @@ -266,6 +266,7 @@ static void put_pasid_state(struct pasid_state *pasid_state) static void put_pasid_state_wait(struct pasid_state *pasid_state) { + atomic_dec(&pasid_state->count); wait_event(pasid_state->wq, !atomic_read(&pasid_state->count)); free_pasid_state(pasid_state); } -- 1.9.1 _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
