Commit 1bf1b431 authored Apr 16, 2015 by Oded Gabbay Committed by Joerg Roedel May 04, 2015

iommu/amd: Fix bug in put_pasid_state_wait



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 <oded.gabbay@amd.com>
Cc: stable@vger.kernel.org #v4.0
Signed-off-by: Joerg Roedel <jroedel@suse.de>

parent 5ebe6afa

drivers/iommu/amd_iommu_v2.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -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);
		}