From c02895577b834a6148f6d9d0006a6f196511cc79 Mon Sep 17 00:00:00 2001 From: Felix Kuehling Date: Mon, 8 Aug 2022 17:00:38 -0400 Subject: [PATCH] drm/amdkfd: Fix mm reference in SVM eviction worker Use the mm reference from the fence. This allows removing the svm_bo->svms pointer, which was problematic because we cannot assume that the struct kfd_process containing the svms is still allocated without holding a refcount on the process. Use mmget_not_zero to ensure the mm is still valid, and drop the svm_bo reference if it isn't. Signed-off-by: Felix Kuehling Reviewed-by: Philip Yang Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 17 +++++++---------- drivers/gpu/drm/amd/amdkfd/kfd_svm.h | 1 - 2 files changed, 7 insertions(+), 11 deletions(-) diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c index a67ba8879a56..11074cc8c333 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c @@ -541,7 +541,6 @@ svm_range_vram_node_new(struct amdgpu_device *adev, struct svm_range *prange, kfree(svm_bo); return -ESRCH; } - svm_bo->svms = prange->svms; svm_bo->eviction_fence = amdgpu_amdkfd_fence_create(dma_fence_context_alloc(1), mm, @@ -3273,7 +3272,6 @@ int svm_range_schedule_evict_svm_bo(struct amdgpu_amdkfd_fence *fence) static void svm_range_evict_svm_bo_worker(struct work_struct *work) { struct svm_range_bo *svm_bo; - struct kfd_process *p; struct mm_struct *mm; int r = 0; @@ -3281,13 +3279,12 @@ static void svm_range_evict_svm_bo_worker(struct work_struct *work) if (!svm_bo_ref_unless_zero(svm_bo)) return; /* svm_bo was freed while eviction was pending */ - /* svm_range_bo_release destroys this worker thread. So during - * the lifetime of this thread, kfd_process and mm will be valid. - */ - p = container_of(svm_bo->svms, struct kfd_process, svms); - mm = p->mm; - if (!mm) + if (mmget_not_zero(svm_bo->eviction_fence->mm)) { + mm = svm_bo->eviction_fence->mm; + } else { + svm_range_bo_unref(svm_bo); return; + } mmap_read_lock(mm); spin_lock(&svm_bo->list_lock); @@ -3305,8 +3302,7 @@ static void svm_range_evict_svm_bo_worker(struct work_struct *work) mutex_lock(&prange->migrate_mutex); do { - r = svm_migrate_vram_to_ram(prange, - svm_bo->eviction_fence->mm, + r = svm_migrate_vram_to_ram(prange, mm, KFD_MIGRATE_TRIGGER_TTM_EVICTION); } while (!r && prange->actual_loc && --retries); @@ -3324,6 +3320,7 @@ static void svm_range_evict_svm_bo_worker(struct work_struct *work) } spin_unlock(&svm_bo->list_lock); mmap_read_unlock(mm); + mmput(mm); dma_fence_signal(&svm_bo->eviction_fence->base); diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.h b/drivers/gpu/drm/amd/amdkfd/kfd_svm.h index 9156b041ef17..cfac13ad06ef 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.h +++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.h @@ -46,7 +46,6 @@ struct svm_range_bo { spinlock_t list_lock; struct amdgpu_amdkfd_fence *eviction_fence; struct work_struct eviction_work; - struct svm_range_list *svms; uint32_t evicting; struct work_struct release_work; }; -- 2.39.5