1// SPDX-License-Identifier: GPL-2.0
2/* Copyright (c) 2023 Meta Platforms, Inc. and affiliates. */
3
4#include <vmlinux.h>
5#include <bpf/bpf_helpers.h>
6#include <bpf/bpf_tracing.h>
7#include <bpf/bpf_core_read.h>
8#include "../bpf_experimental.h"
9#include "bpf_misc.h"
10
11struct node_data {
12	long key;
13	long data;
14	struct bpf_rb_node node;
15};
16
17struct map_value {
18	struct node_data __kptr *node;
19};
20
21struct node_data2 {
22	long key[4];
23};
24
25/* This is necessary so that LLVM generates BTF for node_data struct
26 * If it's not included, a fwd reference for node_data will be generated but
27 * no struct. Example BTF of "node" field in map_value when not included:
28 *
29 * [10] PTR '(anon)' type_id=35
30 * [34] FWD 'node_data' fwd_kind=struct
31 * [35] TYPE_TAG 'kptr_ref' type_id=34
32 */
33struct node_data *just_here_because_btf_bug;
34
35struct {
36	__uint(type, BPF_MAP_TYPE_ARRAY);
37	__type(key, int);
38	__type(value, struct map_value);
39	__uint(max_entries, 2);
40} some_nodes SEC(".maps");
41
42SEC("tc")
43__failure __msg("invalid kptr access, R2 type=ptr_node_data2 expected=ptr_node_data")
44long stash_rb_nodes(void *ctx)
45{
46	struct map_value *mapval;
47	struct node_data2 *res;
48	int idx = 0;
49
50	mapval = bpf_map_lookup_elem(&some_nodes, &idx);
51	if (!mapval)
52		return 1;
53
54	res = bpf_obj_new(typeof(*res));
55	if (!res)
56		return 1;
57	res->key[0] = 40;
58
59	res = bpf_kptr_xchg(&mapval->node, res);
60	if (res)
61		bpf_obj_drop(res);
62	return 0;
63}
64
65SEC("tc")
66__failure __msg("R1 must have zero offset when passed to release func")
67long drop_rb_node_off(void *ctx)
68{
69	struct map_value *mapval;
70	struct node_data *res;
71	int idx = 0;
72
73	mapval = bpf_map_lookup_elem(&some_nodes, &idx);
74	if (!mapval)
75		return 1;
76
77	res = bpf_obj_new(typeof(*res));
78	if (!res)
79		return 1;
80	/* Try releasing with graph node offset */
81	bpf_obj_drop(&res->node);
82	return 0;
83}
84
85char _license[] SEC("license") = "GPL";
86