selftests/bpf: rbtree: Fix incorrect global variable usage

Within __add_three() function, should use function parameters instead of
global variables. So that the variables groot_nested.inner.root and
groot_nested.inner.glock in rbtree_add_nodes_nested() are tested
correctly.

Signed-off-by: Rong Tao <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>

Author: Rtoax

tools/testing/selftests/bpf/progs/rbtree.c

@@ -61,19 +61,19 @@ static long __add_three(struct bpf_rb_root *root, struct bpf_spin_lock *lock)
 	}
 	m->key = 1;
 
-	bpf_spin_lock(&glock);
-	bpf_rbtree_add(&groot, &n->node, less);
-	bpf_rbtree_add(&groot, &m->node, less);
-	bpf_spin_unlock(&glock);
+	bpf_spin_lock(lock);
+	bpf_rbtree_add(root, &n->node, less);
+	bpf_rbtree_add(root, &m->node, less);
+	bpf_spin_unlock(lock);
 
 	n = bpf_obj_new(typeof(*n));
 	if (!n)
 		return 3;
 	n->key = 3;
 
-	bpf_spin_lock(&glock);
-	bpf_rbtree_add(&groot, &n->node, less);
-	bpf_spin_unlock(&glock);
+	bpf_spin_lock(lock);
+	bpf_rbtree_add(root, &n->node, less);
+	bpf_spin_unlock(lock);
 	return 0;
 }