[PATCH] drm/amdkfd: Fix 'node' NULL check in 'svm_range_get_range_boundaries()'

[Srinivasan Shanmugam]

Range interval [start, last] is ordered by rb_tree, rb_prev, rb_next
return value still needs NULL check, thus modified from "node" to "rb_node".

Fixes the below:
drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_svm.c:2691 
svm_range_get_range_boundaries() warn: can 'node' even be NULL?

Suggested-by: Philip Yang <philip.y...@amd.com>
Cc: Felix Kuehling <felix.kuehl...@amd.com>
Cc: Christian König <christian.koe...@amd.com>
Cc: Alex Deucher <alexander.deuc...@amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmu...@amd.com>
---
 drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c 
b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
index 3b78e48832e9..6aa032731ddc 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
@@ -2656,6 +2656,7 @@ svm_range_get_range_boundaries(struct kfd_process *p, 
int64_t addr,
 {
        struct vm_area_struct *vma;
        struct interval_tree_node *node;
+       struct rb_node *rb_node;
        unsigned long start_limit, end_limit;
 
        vma = vma_lookup(p->mm, addr << PAGE_SHIFT);
@@ -2678,16 +2679,15 @@ svm_range_get_range_boundaries(struct kfd_process *p, 
int64_t addr,
        if (node) {
                end_limit = min(end_limit, node->start);
                /* Last range that ends before the fault address */
-               node = container_of(rb_prev(&node->rb),
-                                   struct interval_tree_node, rb);
+               rb_node = rb_prev(&node->rb);
        } else {
                /* Last range must end before addr because
                 * there was no range after addr
                 */
-               node = container_of(rb_last(&p->svms.objects.rb_root),
-                                   struct interval_tree_node, rb);
+               rb_node = rb_last(&p->svms.objects.rb_root);
        }
-       if (node) {
+       if (rb_node) {
+               node = container_of(rb_node, struct interval_tree_node, rb);
                if (node->last >= addr) {
                        WARN(1, "Overlap with prev node and page fault addr\n");
                        return -EFAULT;
-- 
2.34.1