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 { 21 __uint(type, BPF_MAP_TYPE_ARRAY); 22 __type(key, int); 23 __type(value, struct map_value); 24 __uint(max_entries, 1); 25 } array SEC(".maps"); 26 27 char _license[] SEC("license") = "GPL"; 28 29 int pid = 0; 30 bool done = false; 31 32 SEC("fentry/" SYS_PREFIX "sys_nanosleep") 33 int add_to_list_in_array(void *ctx) 34 { 35 struct map_value *value; 36 struct node_data *new; 37 int zero = 0; 38 39 if (done || (int)bpf_get_current_pid_tgid() != pid) 40 return 0; 41 42 value = bpf_map_lookup_elem(&array, &zero); 43 if (!value) 44 return 0; 45 46 new = bpf_obj_new(typeof(*new)); 47 if (!new) 48 return 0; 49 50 bpf_spin_lock(&value->lock); 51 bpf_list_push_back(&value->head, &new->node); 52 bpf_spin_unlock(&value->lock); 53 done = true; 54 55 return 0; 56 } 57