1 // SPDX-License-Identifier: GPL-2.0 2 // Copyright (c) 2020 Facebook 3 4 #include <linux/ptrace.h> 5 #include <linux/bpf.h> 6 #include <bpf/bpf_helpers.h> 7 #include <bpf/bpf_tracing.h> 8 9 #define VAR_NUM 2 10 11 struct hmap_elem { 12 struct bpf_spin_lock lock; 13 int var[VAR_NUM]; 14 }; 15 16 struct { 17 __uint(type, BPF_MAP_TYPE_HASH); 18 __uint(max_entries, 1); 19 __type(key, __u32); 20 __type(value, struct hmap_elem); 21 } hash_map SEC(".maps"); 22 23 SEC("freplace/handle_kprobe") 24 int new_handle_kprobe(struct pt_regs *ctx) 25 { 26 struct hmap_elem *val; 27 int key = 0; 28 29 val = bpf_map_lookup_elem(&hash_map, &key); 30 if (!val) 31 return 1; 32 /* spin_lock in hash map */ 33 bpf_spin_lock(&val->lock); 34 val->var[0] = 99; 35 bpf_spin_unlock(&val->lock); 36 37 return 0; 38 } 39 40 char _license[] SEC("license") = "GPL"; 41