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drm/amdkfd: handle VMA remove race

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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 <Philip.Yang@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
This commit is contained in:
Philip Yang 2021-11-19 16:16:39 -05:00 committed by Alex Deucher
parent cda0817b41
commit 0cc53cb450
1 changed files with 13 additions and 9 deletions
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22
drivers/gpu/drm/amd/amdkfd/kfd_svm.c
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@ -2559,20 +2559,13 @@ 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;
@ -2590,6 +2583,7 @@ 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)) {
@ -2665,7 +2659,17 @@ retry_write_locked:
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;