From: Fenghua Yu fenghua.yu@intel.com
[ Upstream commit a21518cb23a3c7d49bafcb59862fd389fd829d4b ]
The mm->pasid will be used in intel_svm_free_pasid() after load_pasid() during unbinding mm. Clearing it in load_pasid() will cause PASID cannot be freed in intel_svm_free_pasid().
Additionally mm->pasid was updated already before load_pasid() during pasid allocation. No need to update it again in load_pasid() during binding mm. Don't update mm->pasid to avoid the issues in both binding mm and unbinding mm.
Fixes: 4048377414162 ("iommu/vt-d: Use iommu_sva_alloc(free)_pasid() helpers") Reported-and-tested-by: Dave Jiang dave.jiang@intel.com Co-developed-by: Jacob Pan jacob.jun.pan@linux.intel.com Signed-off-by: Jacob Pan jacob.jun.pan@linux.intel.com Signed-off-by: Fenghua Yu fenghua.yu@intel.com Link: https://lore.kernel.org/r/20210826215918.4073446-1-fenghua.yu@intel.com Signed-off-by: Lu Baolu baolu.lu@linux.intel.com Link: https://lore.kernel.org/r/20210828070622.2437559-2-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel jroedel@suse.de Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/iommu/intel/svm.c | 3 --- 1 file changed, 3 deletions(-)
diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c index 4b9b3f35ba0e..ceeca633a5f9 100644 --- a/drivers/iommu/intel/svm.c +++ b/drivers/iommu/intel/svm.c @@ -516,9 +516,6 @@ static void load_pasid(struct mm_struct *mm, u32 pasid) { mutex_lock(&mm->context.lock);
- /* Synchronize with READ_ONCE in update_pasid(). */ - smp_store_release(&mm->pasid, pasid); - /* Update PASID MSR on all CPUs running the mm's tasks. */ on_each_cpu_mask(mm_cpumask(mm), _load_pasid, NULL, true);