Re: [PATCH] iommu/vt-d: Fix PASID reference leak
On 2021/8/14 2:13, Fenghua Yu wrote: A PASID reference is increased whenever a device is bound to an mm (and its PASID) successfully (i.e. the device's sdev user count is increased). But the reference is not dropped every time the device is unbound successfully from the mm (i.e. the device's sdev user count is decreased). The reference is dropped only once by calling intel_svm_free_pasid() when there isn't any device bound to the mm. intel_svm_free_pasid() drops the reference and only frees the PASID on zero reference. Fix the issue by dropping the PASID reference and freeing the PASID when no reference on successful unbinding the device by calling intel_svm_free_pasid() . Signed-off-by: Fenghua Yu Patch has been queued for iommu/fix. Best regards, baolu ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
Re: [PATCH] iommu/vt-d: Fix PASID reference leak
On 2021/8/14 2:13, Fenghua Yu wrote: A PASID reference is increased whenever a device is bound to an mm (and its PASID) successfully (i.e. the device's sdev user count is increased). But the reference is not dropped every time the device is unbound successfully from the mm (i.e. the device's sdev user count is decreased). The reference is dropped only once by calling intel_svm_free_pasid() when there isn't any device bound to the mm. intel_svm_free_pasid() drops the reference and only frees the PASID on zero reference. Fix the issue by dropping the PASID reference and freeing the PASID when no reference on successful unbinding the device by calling intel_svm_free_pasid() . Signed-off-by: Fenghua Yu Nice catch! Thanks! Fixes: 4048377414162 ("iommu/vt-d: Use iommu_sva_alloc(free)_pasid() helpers") Acked-by: Lu Baolu Best regards, baolu --- drivers/iommu/intel/svm.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c index 9b0f22bc0514..4b9b3f35ba0e 100644 --- a/drivers/iommu/intel/svm.c +++ b/drivers/iommu/intel/svm.c @@ -675,7 +675,6 @@ static int intel_svm_unbind_mm(struct device *dev, u32 pasid) kfree_rcu(sdev, rcu); if (list_empty(>devs)) { - intel_svm_free_pasid(mm); if (svm->notifier.ops) { mmu_notifier_unregister(>notifier, mm); /* Clear mm's pasid. */ @@ -690,6 +689,8 @@ static int intel_svm_unbind_mm(struct device *dev, u32 pasid) kfree(svm); } } + /* Drop a PASID reference and free it if no reference. */ + intel_svm_free_pasid(mm); } out: return ret; ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
[PATCH] iommu/vt-d: Fix PASID reference leak
A PASID reference is increased whenever a device is bound to an mm (and its PASID) successfully (i.e. the device's sdev user count is increased). But the reference is not dropped every time the device is unbound successfully from the mm (i.e. the device's sdev user count is decreased). The reference is dropped only once by calling intel_svm_free_pasid() when there isn't any device bound to the mm. intel_svm_free_pasid() drops the reference and only frees the PASID on zero reference. Fix the issue by dropping the PASID reference and freeing the PASID when no reference on successful unbinding the device by calling intel_svm_free_pasid() . Signed-off-by: Fenghua Yu --- drivers/iommu/intel/svm.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c index 9b0f22bc0514..4b9b3f35ba0e 100644 --- a/drivers/iommu/intel/svm.c +++ b/drivers/iommu/intel/svm.c @@ -675,7 +675,6 @@ static int intel_svm_unbind_mm(struct device *dev, u32 pasid) kfree_rcu(sdev, rcu); if (list_empty(>devs)) { - intel_svm_free_pasid(mm); if (svm->notifier.ops) { mmu_notifier_unregister(>notifier, mm); /* Clear mm's pasid. */ @@ -690,6 +689,8 @@ static int intel_svm_unbind_mm(struct device *dev, u32 pasid) kfree(svm); } } + /* Drop a PASID reference and free it if no reference. */ + intel_svm_free_pasid(mm); } out: return ret; -- 2.32.0 ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu