From: Philip Yang <[email protected]>

[ Upstream commit 0cc53cb450669cf1def4ff89e8cbcd8ec3c62380 ]

VMA may be removed before unmap notifier callback, and deferred list
work remove range, return success for this special case as we are
handling stale retry fault.

Signed-off-by: Philip Yang <[email protected]>
Reviewed-by: Felix Kuehling <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
---
 drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c 
b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
index 179080329af89..4e933fb0fc698 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
@@ -2448,20 +2448,13 @@ svm_range_count_fault(struct amdgpu_device *adev, 
struct kfd_process *p,
 }
 
 static bool
-svm_fault_allowed(struct mm_struct *mm, uint64_t addr, bool write_fault)
+svm_fault_allowed(struct vm_area_struct *vma, bool write_fault)
 {
        unsigned long requested = VM_READ;
-       struct vm_area_struct *vma;
 
        if (write_fault)
                requested |= VM_WRITE;
 
-       vma = find_vma(mm, addr << PAGE_SHIFT);
-       if (!vma || (addr << PAGE_SHIFT) < vma->vm_start) {
-               pr_debug("address 0x%llx VMA is removed\n", addr);
-               return true;
-       }
-
        pr_debug("requested 0x%lx, vma permission flags 0x%lx\n", requested,
                vma->vm_flags);
        return (vma->vm_flags & requested) == requested;
@@ -2479,6 +2472,7 @@ svm_range_restore_pages(struct amdgpu_device *adev, 
unsigned int pasid,
        int32_t best_loc;
        int32_t gpuidx = MAX_GPU_INSTANCE;
        bool write_locked = false;
+       struct vm_area_struct *vma;
        int r = 0;
 
        if (!KFD_IS_SVM_API_SUPPORTED(adev->kfd.dev)) {
@@ -2552,7 +2546,17 @@ svm_range_restore_pages(struct amdgpu_device *adev, 
unsigned int pasid,
                goto out_unlock_range;
        }
 
-       if (!svm_fault_allowed(mm, addr, write_fault)) {
+       /* __do_munmap removed VMA, return success as we are handling stale
+        * retry fault.
+        */
+       vma = find_vma(mm, addr << PAGE_SHIFT);
+       if (!vma || (addr << PAGE_SHIFT) < vma->vm_start) {
+               pr_debug("address 0x%llx VMA is removed\n", addr);
+               r = 0;
+               goto out_unlock_range;
+       }
+
+       if (!svm_fault_allowed(vma, write_fault)) {
                pr_debug("fault addr 0x%llx no %s permission\n", addr,
                        write_fault ? "write" : "read");
                r = -EPERM;
-- 
2.33.0

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