Hi! > From: Xiyu Yang <xiyuyang19@xxxxxxxxxxxx> > > [ Upstream commit 1adf30f198c26539a62d761e45af72cde570413d ] > > arm_smmu_rpm_get() invokes pm_runtime_get_sync(), which increases the > refcount of the "smmu" even though the return value is less than 0. Yes. > The reference counting issue happens in some error handling paths of > arm_smmu_rpm_get() in its caller functions. When arm_smmu_rpm_get() > fails, the caller functions forget to decrease the refcount of "smmu" > increased by arm_smmu_rpm_get(), causing a refcount leak. Yes, some error paths do that. But some callers (arm_smmu_map, arm_smmu_unmap, arm_smmu_flush_iotlb_all, ...) ignore return value of arm_smmu_rpm_get(). > Fix this issue by calling pm_runtime_resume_and_get() instead of > pm_runtime_get_sync() in arm_smmu_rpm_get(), which can keep the refcount > balanced in case of failure. So no, this is not fixed; it is just unbalanced in the other (more dangerous) direction now. Best regards, Pavel -- DENX Software Engineering GmbH, Managing Director: Wolfgang Denk HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
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