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// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2026 KylinSoft Corporation. */
#include <vmlinux.h>
#include <bpf/bpf_helpers.h>
#include "bpf_misc.h"
#include "bpf_experimental.h"
#define NR_NODES 16
struct node_data {
int data;
};
struct tree_node {
struct bpf_rb_node node;
u64 key;
struct node_data __kptr * node_data;
};
struct tree_node_ref {
struct bpf_refcount ref;
struct bpf_rb_node node;
u64 key;
struct node_data __kptr * node_data;
};
#define private(name) SEC(".data." #name) __hidden __aligned(8)
private(A) struct bpf_rb_root root __contains(tree_node, node);
private(A) struct bpf_spin_lock lock;
private(B) struct bpf_rb_root root_r __contains(tree_node_ref, node);
private(B) struct bpf_spin_lock lock_r;
static bool less(struct bpf_rb_node *a, const struct bpf_rb_node *b)
{
struct tree_node *node_a, *node_b;
node_a = container_of(a, struct tree_node, node);
node_b = container_of(b, struct tree_node, node);
return node_a->key < node_b->key;
}
SEC("syscall")
__retval(0)
long rbtree_search_kptr(void *ctx)
{
struct tree_node *tnode;
struct bpf_rb_node *rb_n;
struct node_data __kptr * node_data;
int lookup_key = NR_NODES / 2;
int lookup_data = NR_NODES / 2;
int i, data, ret = 0;
for (i = 0; i < NR_NODES && can_loop; i++) {
tnode = bpf_obj_new(typeof(*tnode));
if (!tnode)
return __LINE__;
node_data = bpf_obj_new(typeof(*node_data));
if (!node_data) {
bpf_obj_drop(tnode);
return __LINE__;
}
tnode->key = i;
node_data->data = i;
node_data = bpf_kptr_xchg(&tnode->node_data, node_data);
if (node_data)
bpf_obj_drop(node_data);
bpf_spin_lock(&lock);
bpf_rbtree_add(&root, &tnode->node, less);
bpf_spin_unlock(&lock);
}
bpf_spin_lock(&lock);
rb_n = bpf_rbtree_root(&root);
while (rb_n && can_loop) {
tnode = container_of(rb_n, struct tree_node, node);
node_data = bpf_kptr_xchg(&tnode->node_data, NULL);
if (!node_data) {
ret = __LINE__;
goto fail;
}
data = node_data->data;
node_data = bpf_kptr_xchg(&tnode->node_data, node_data);
if (node_data) {
bpf_spin_unlock(&lock);
bpf_obj_drop(node_data);
return __LINE__;
}
if (lookup_key == tnode->key) {
if (data == lookup_data)
break;
ret = __LINE__;
goto fail;
}
if (lookup_key < tnode->key)
rb_n = bpf_rbtree_left(&root, rb_n);
else
rb_n = bpf_rbtree_right(&root, rb_n);
}
bpf_spin_unlock(&lock);
while (can_loop) {
bpf_spin_lock(&lock);
rb_n = bpf_rbtree_first(&root);
if (!rb_n) {
bpf_spin_unlock(&lock);
return 0;
}
rb_n = bpf_rbtree_remove(&root, rb_n);
if (!rb_n) {
ret = __LINE__;
goto fail;
}
bpf_spin_unlock(&lock);
tnode = container_of(rb_n, struct tree_node, node);
node_data = bpf_kptr_xchg(&tnode->node_data, NULL);
if (node_data)
bpf_obj_drop(node_data);
bpf_obj_drop(tnode);
}
return 0;
fail:
bpf_spin_unlock(&lock);
return ret;
}
static bool less_r(struct bpf_rb_node *a, const struct bpf_rb_node *b)
{
struct tree_node_ref *node_a, *node_b;
node_a = container_of(a, struct tree_node_ref, node);
node_b = container_of(b, struct tree_node_ref, node);
return node_a->key < node_b->key;
}
SEC("syscall")
__retval(0)
long rbtree_search_kptr_ref(void *ctx)
{
struct tree_node_ref *tnode_r, *tnode_m;
struct bpf_rb_node *rb_n;
struct node_data __kptr * node_data;
int lookup_key = NR_NODES / 2;
int lookup_data = NR_NODES / 2;
int i, data, ret = 0;
for (i = 0; i < NR_NODES && can_loop; i++) {
tnode_r = bpf_obj_new(typeof(*tnode_r));
if (!tnode_r)
return __LINE__;
node_data = bpf_obj_new(typeof(*node_data));
if (!node_data) {
bpf_obj_drop(tnode_r);
return __LINE__;
}
tnode_r->key = i;
node_data->data = i;
node_data = bpf_kptr_xchg(&tnode_r->node_data, node_data);
if (node_data)
bpf_obj_drop(node_data);
/* Unused reference */
tnode_m = bpf_refcount_acquire(tnode_r);
if (!tnode_m)
return __LINE__;
bpf_spin_lock(&lock_r);
bpf_rbtree_add(&root_r, &tnode_r->node, less_r);
bpf_spin_unlock(&lock_r);
bpf_obj_drop(tnode_m);
}
bpf_spin_lock(&lock_r);
rb_n = bpf_rbtree_root(&root_r);
while (rb_n && can_loop) {
tnode_r = container_of(rb_n, struct tree_node_ref, node);
node_data = bpf_kptr_xchg(&tnode_r->node_data, NULL);
if (!node_data) {
ret = __LINE__;
goto fail;
}
data = node_data->data;
node_data = bpf_kptr_xchg(&tnode_r->node_data, node_data);
if (node_data) {
bpf_spin_unlock(&lock_r);
bpf_obj_drop(node_data);
return __LINE__;
}
if (lookup_key == tnode_r->key) {
if (data == lookup_data)
break;
ret = __LINE__;
goto fail;
}
if (lookup_key < tnode_r->key)
rb_n = bpf_rbtree_left(&root_r, rb_n);
else
rb_n = bpf_rbtree_right(&root_r, rb_n);
}
bpf_spin_unlock(&lock_r);
while (can_loop) {
bpf_spin_lock(&lock_r);
rb_n = bpf_rbtree_first(&root_r);
if (!rb_n) {
bpf_spin_unlock(&lock_r);
return 0;
}
rb_n = bpf_rbtree_remove(&root_r, rb_n);
if (!rb_n) {
ret = __LINE__;
goto fail;
}
bpf_spin_unlock(&lock_r);
tnode_r = container_of(rb_n, struct tree_node_ref, node);
node_data = bpf_kptr_xchg(&tnode_r->node_data, NULL);
if (node_data)
bpf_obj_drop(node_data);
bpf_obj_drop(tnode_r);
}
return 0;
fail:
bpf_spin_unlock(&lock_r);
return ret;
}
SEC("syscall")
__failure __msg("R1 type=scalar expected=map_value, ptr_, ptr_")
long non_own_ref_kptr_xchg_no_lock(void *ctx)
{
struct tree_node *tnode;
struct bpf_rb_node *rb_n;
struct node_data __kptr * node_data;
int data;
bpf_spin_lock(&lock);
rb_n = bpf_rbtree_first(&root);
if (!rb_n) {
bpf_spin_unlock(&lock);
return __LINE__;
}
bpf_spin_unlock(&lock);
tnode = container_of(rb_n, struct tree_node, node);
node_data = bpf_kptr_xchg(&tnode->node_data, NULL);
if (!node_data)
return __LINE__;
data = node_data->data;
if (data < 0)
return __LINE__;
node_data = bpf_kptr_xchg(&tnode->node_data, node_data);
if (node_data)
return __LINE__;
return 0;
}
char _license[] SEC("license") = "GPL";
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