[PATCH v2] iommu/arm-smmu-v3: Free MSIs in case of ENOMEM

[Aleksandr Aprelkov]

If devm_add_action() returns ENOMEM, then MSIs allocated but
not freed on teardown.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 166bdbd23161 ("iommu/arm-smmu: Add support for MSI on SMMUv3")
Signed-off-by: Aleksandr Aprelkov <aaprelkov@xxxxxxxxxxxx>
---
v2: Use appropriate function for registration failure as 
Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> suggested.

 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index 41f93c3ab160..8800af041e5f 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -3402,7 +3402,9 @@ static void arm_smmu_setup_msis(struct arm_smmu_device *smmu)
 	smmu->priq.q.irq = msi_get_virq(dev, PRIQ_MSI_INDEX);
 
 	/* Add callback to free MSIs on teardown */
-	devm_add_action(dev, arm_smmu_free_msis, dev);
+	ret = devm_add_action_or_reset(dev, arm_smmu_free_msis, dev);
+	if (ret)
+		dev_warn(dev, "failed to add free MSIs callback - falling back to wired irqs\n");
 }
 
 static void arm_smmu_setup_unique_irqs(struct arm_smmu_device *smmu)
-- 
2.34.1