From: Joerg Roedel <[email protected]> With calling te mmu_notifier_register function we hold a reference to the mm_struct that needs to be released in mmu_notifier_unregister. This is true even if the notifier was already unregistered from exit_mmap and the .release call-back has already run.
So make sure we call mmu_notifier_unregister unconditionally in amd_iommu_unbind_pasid. Signed-off-by: Joerg Roedel <[email protected]> Tested-by: Oded Gabbay <[email protected]> --- drivers/iommu/amd_iommu_v2.c | 20 +++----------------- 1 file changed, 3 insertions(+), 17 deletions(-) diff --git a/drivers/iommu/amd_iommu_v2.c b/drivers/iommu/amd_iommu_v2.c index a195c78..2b7de88 100644 --- a/drivers/iommu/amd_iommu_v2.c +++ b/drivers/iommu/amd_iommu_v2.c @@ -320,13 +320,6 @@ static void unbind_pasid(struct pasid_state *pasid_state) /* Make sure no more pending faults are in the queue */ flush_workqueue(iommu_wq); - - /* - * No more faults are in the work queue and no new faults will be queued - * from here on. We can safely set pasid_state->mm to NULL now as the - * mm_struct might go away after we return. - */ - pasid_state->mm = NULL; } static void free_pasid_states_level1(struct pasid_state **tbl) @@ -756,17 +749,10 @@ void amd_iommu_unbind_pasid(struct pci_dev *pdev, int pasid) clear_pasid_state(dev_state, pasid_state->pasid); /* - * Check if pasid_state->mm is still valid. If mn_release has already - * run it will be NULL and we can't (and don't need to) call - * mmu_notifier_unregister() on it anymore. + * Call mmu_notifier_unregister to drop our reference + * to pasid_state->mm */ - if (pasid_state->mm) { - /* - * This will call the mn_release function and unbind - * the PASID. - */ - mmu_notifier_unregister(&pasid_state->mn, pasid_state->mm); - } + mmu_notifier_unregister(&pasid_state->mn, pasid_state->mm); put_pasid_state_wait(pasid_state); /* Reference taken in amd_iommu_pasid_bind */ -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
