Before restore pages takes mmap read or write lock, vma maybe removed.
Check if vma exists before creating unregistered range or verifying
range access permission, and return 0 if vma is removed to avoid restore
pages return failure to report GPU vm fault to application.
Signed-off-by: Philip Yang <philip.y...@amd.com>
---
drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 64 ++++++++++++++++------------
1 file changed, 37 insertions(+), 27 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
index 64f642935600..8f77d5746b2c 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
@@ -2336,20 +2336,13 @@ svm_range_best_restore_location(struct svm_range
*prange,
}
static int
-svm_range_get_range_boundaries(struct kfd_process *p, int64_t addr,
- unsigned long *start, unsigned long *last,
- bool *is_heap_stack)
+svm_range_get_range_boundaries(struct kfd_process *p, struct vm_area_struct
*vma,
+ int64_t addr, unsigned long *start,
+ unsigned long *last, bool *is_heap_stack)
{
- struct vm_area_struct *vma;
struct interval_tree_node *node;
unsigned long start_limit, end_limit;
- vma = find_vma(p->mm, addr << PAGE_SHIFT);
- if (!vma || (addr << PAGE_SHIFT) < vma->vm_start) {
- pr_debug("VMA does not exist in address [0x%llx]\n", addr);
- return -EFAULT;
- }
-
*is_heap_stack = (vma->vm_start <= vma->vm_mm->brk &&
vma->vm_end >= vma->vm_mm->start_brk) ||
(vma->vm_start <= vma->vm_mm->start_stack &&
@@ -2444,9 +2437,10 @@ svm_range_check_vm_userptr(struct kfd_process *p,
uint64_t start, uint64_t last,
static struct
svm_range *svm_range_create_unregistered_range(struct amdgpu_device *adev,
- struct kfd_process *p,
- struct mm_struct *mm,
- int64_t addr)
+ struct kfd_process *p,
+ struct mm_struct *mm,
+ struct vm_area_struct *vma,
+ int64_t addr)
{
struct svm_range *prange = NULL;
unsigned long start, last;
@@ -2456,7 +2450,7 @@ svm_range *svm_range_create_unregistered_range(struct
amdgpu_device *adev,
uint64_t bo_l = 0;
int r;
- if (svm_range_get_range_boundaries(p, addr, &start, &last,
+ if (svm_range_get_range_boundaries(p, vma, addr, &start, &last,
&is_heap_stack))
return NULL;
@@ -2558,21 +2552,22 @@ svm_range_count_fault(struct amdgpu_device *adev,
struct kfd_process *p,
WRITE_ONCE(pdd->faults, pdd->faults + 1);
}
-static bool
-svm_fault_allowed(struct mm_struct *mm, uint64_t addr, bool write_fault)
+static int
+svm_fault_allowed(struct mm_struct *mm, struct vm_area_struct *vma,
+ uint64_t addr, 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;
+ if (!vma) {
+ 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 -EFAULT;
+ }
}
-
pr_debug("requested 0x%lx, vma permission flags 0x%lx\n", requested,
vma->vm_flags);
return (vma->vm_flags & requested) == requested;
@@ -2590,6 +2585,7 @@ 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 = NULL;
int r = 0;
if (!KFD_IS_SVM_API_SUPPORTED(adev->kfd.dev)) {
@@ -2636,7 +2632,15 @@ svm_range_restore_pages(struct amdgpu_device *adev,
unsigned int pasid,
write_locked = true;
goto retry_write_locked;
}
- prange = svm_range_create_unregistered_range(adev, p, mm, addr);
+
+ vma = find_vma(p->mm, addr << PAGE_SHIFT);
+ if (!vma || (addr << PAGE_SHIFT) < vma->vm_start) {
+ pr_debug("VMA not found address [0x%llx]\n", addr);
+ mmap_write_downgrade(mm);
+ r = 0;
+ goto out_unlock_svms;
+ }
+ prange = svm_range_create_unregistered_range(adev, p, mm, vma,
addr);
if (!prange) {
pr_debug("failed to create unregistered range svms 0x%p
address [0x%llx]\n",
svms, addr);
@@ -2663,10 +2667,16 @@ svm_range_restore_pages(struct amdgpu_device *adev,
unsigned int pasid,
goto out_unlock_range;
}
- if (!svm_fault_allowed(mm, addr, write_fault)) {
- pr_debug("fault addr 0x%llx no %s permission\n", addr,
- write_fault ? "write" : "read");
- r = -EPERM;
+ r = svm_fault_allowed(mm, vma, addr, write_fault);
+ if (r <= 0) {
+ if (!r) {
+ pr_debug("fault addr 0x%llx no %s permission\n", addr,
+ write_fault ? "write" : "read");
+ r = -EPERM;
+ } else {
+ pr_debug("fault addr 0x%llx is unmapping\n", addr);
+ r = 0;
+ }
goto out_unlock_range;
}
--
2.17.1
