1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright (C) 2023. Huawei Technologies Co., Ltd */ 3 #include <vmlinux.h> 4 #include <bpf/bpf_tracing.h> 5 #include <bpf/bpf_helpers.h> 6 7 #include "bpf_misc.h" 8 #include "bpf_experimental.h" 9 10 struct node_data { 11 __u64 data; 12 struct bpf_list_node node; 13 }; 14 15 struct map_value { 16 struct bpf_list_head head __contains(node_data, node); 17 struct bpf_spin_lock lock; 18 }; 19 20 struct inner_array_type { 21 __uint(type, BPF_MAP_TYPE_ARRAY); 22 __type(key, int); 23 __type(value, struct map_value); 24 __uint(max_entries, 1); 25 } inner_array SEC(".maps"); 26 27 struct { 28 __uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS); 29 __uint(key_size, 4); 30 __uint(value_size, 4); 31 __uint(max_entries, 1); 32 __array(values, struct inner_array_type); 33 } outer_array SEC(".maps") = { 34 .values = { 35 [0] = &inner_array, 36 }, 37 }; 38 39 char _license[] SEC("license") = "GPL"; 40 41 int pid = 0; 42 bool done = false; 43 44 SEC("fentry/" SYS_PREFIX "sys_nanosleep") 45 int add_to_list_in_inner_array(void *ctx) 46 { 47 struct map_value *value; 48 struct node_data *new; 49 struct bpf_map *map; 50 int zero = 0; 51 52 if (done || (u32)bpf_get_current_pid_tgid() != pid) 53 return 0; 54 55 map = bpf_map_lookup_elem(&outer_array, &zero); 56 if (!map) 57 return 0; 58 59 value = bpf_map_lookup_elem(map, &zero); 60 if (!value) 61 return 0; 62 63 new = bpf_obj_new(typeof(*new)); 64 if (!new) 65 return 0; 66 67 bpf_spin_lock(&value->lock); 68 bpf_list_push_back(&value->head, &new->node); 69 bpf_spin_unlock(&value->lock); 70 done = true; 71 72 return 0; 73 } 74