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authorFenghua Yu <fenghua.yu@intel.com>2021-08-17 20:43:20 +0800
committerJoerg Roedel <jroedel@suse.de>2021-08-18 13:15:58 +0200
commit62ef907a045e1a81830941c48004d7af71c9d75a (patch)
tree247165bf15479a794b90d29f384f6a336083d3c1 /drivers
parent5aa95d8834e07907e64937d792c12ffef7fb271f (diff)
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() . Fixes: 4048377414162 ("iommu/vt-d: Use iommu_sva_alloc(free)_pasid() helpers") Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Link: https://lore.kernel.org/r/20210813181345.1870742-1-fenghua.yu@intel.com Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Link: https://lore.kernel.org/r/20210817124321.1517985-2-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/iommu/intel/svm.c3
1 files changed, 2 insertions, 1 deletions
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(&svm->devs)) {
- intel_svm_free_pasid(mm);
if (svm->notifier.ops) {
mmu_notifier_unregister(&svm->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;