// 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";