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 
11 struct node_data {
12 	long key;
13 	long data;
14 	struct bpf_rb_node node;
15 };
16 
17 struct map_value {
18 	struct node_data __kptr *node;
19 };
20 
21 struct 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  */
33 struct node_data *just_here_because_btf_bug;
34 
35 struct {
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 
42 SEC("tc")
43 __failure __msg("invalid kptr access, R2 type=ptr_node_data2 expected=ptr_node_data")
44 long 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 
65 SEC("tc")
66 __failure __msg("R1 must have zero offset when passed to release func")
67 long 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 
85 char _license[] SEC("license") = "GPL";
86