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// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2023 Meta Platforms, Inc. and affiliates. */
#include <vmlinux.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
#include <bpf/bpf_core_read.h>
#include "../bpf_experimental.h"
#include "bpf_misc.h"
struct node_data {
long key;
long data;
struct bpf_rb_node node;
};
struct map_value {
struct node_data __kptr *node;
};
struct node_data2 {
long key[4];
};
/* This is necessary so that LLVM generates BTF for node_data struct
* If it's not included, a fwd reference for node_data will be generated but
* no struct. Example BTF of "node" field in map_value when not included:
*
* [10] PTR '(anon)' type_id=35
* [34] FWD 'node_data' fwd_kind=struct
* [35] TYPE_TAG 'kptr_ref' type_id=34
*/
struct node_data *just_here_because_btf_bug;
struct {
__uint(type, BPF_MAP_TYPE_ARRAY);
__type(key, int);
__type(value, struct map_value);
__uint(max_entries, 2);
} some_nodes SEC(".maps");
SEC("tc")
__failure __msg("invalid kptr access, R2 type=ptr_node_data2 expected=ptr_node_data")
long stash_rb_nodes(void *ctx)
{
struct map_value *mapval;
struct node_data2 *res;
int idx = 0;
mapval = bpf_map_lookup_elem(&some_nodes, &idx);
if (!mapval)
return 1;
res = bpf_obj_new(typeof(*res));
if (!res)
return 1;
res->key[0] = 40;
res = bpf_kptr_xchg(&mapval->node, res);
if (res)
bpf_obj_drop(res);
return 0;
}
SEC("tc")
__failure __msg("R1 must have zero offset when passed to release func")
long drop_rb_node_off(void *ctx)
{
struct map_value *mapval;
struct node_data *res;
int idx = 0;
mapval = bpf_map_lookup_elem(&some_nodes, &idx);
if (!mapval)
return 1;
res = bpf_obj_new(typeof(*res));
if (!res)
return 1;
/* Try releasing with graph node offset */
bpf_obj_drop(&res->node);
return 0;
}
char _license[] SEC("license") = "GPL";
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