[PATCH AUTOSEL for 4.9 49/54] vfio/spapr: Fix missing mutex unlock when creating a window

From: alexander . levin
Date: Wed Nov 22 2017 - 18:15:10 EST


From: Alexey Kardashevskiy <aik@xxxxxxxxx>

[ Upstream commit 2da64d20a0b20046d688e44f4033efd09157e29d ]

Commit d9c728949ddc ("vfio/spapr: Postpone default window creation")
added an additional exit to the VFIO_IOMMU_SPAPR_TCE_CREATE case and
made it possible to return from tce_iommu_ioctl() without unlocking
container->lock; this fixes the issue.

Fixes: d9c728949ddc ("vfio/spapr: Postpone default window creation")
Signed-off-by: Alexey Kardashevskiy <aik@xxxxxxxxx>
Reviewed-by: David Gibson <david@xxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Alex Williamson <alex.williamson@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
---
drivers/vfio/vfio_iommu_spapr_tce.c | 11 +++++------
1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/vfio/vfio_iommu_spapr_tce.c b/drivers/vfio/vfio_iommu_spapr_tce.c
index 85d3e648bdea..59b3f62a2d64 100644
--- a/drivers/vfio/vfio_iommu_spapr_tce.c
+++ b/drivers/vfio/vfio_iommu_spapr_tce.c
@@ -1123,12 +1123,11 @@ static long tce_iommu_ioctl(void *iommu_data,
mutex_lock(&container->lock);

ret = tce_iommu_create_default_window(container);
- if (ret)
- return ret;
-
- ret = tce_iommu_create_window(container, create.page_shift,
- create.window_size, create.levels,
- &create.start_addr);
+ if (!ret)
+ ret = tce_iommu_create_window(container,
+ create.page_shift,
+ create.window_size, create.levels,
+ &create.start_addr);

mutex_unlock(&container->lock);

--
2.11.0