1 /* Copyright (c) 2017 Facebook 2 * 3 * This program is free software; you can redistribute it and/or 4 * modify it under the terms of version 2 of the GNU General Public 5 * License as published by the Free Software Foundation. 6 */ 7 #include <uapi/linux/bpf.h> 8 #include "bpf_helpers.h" 9 10 struct syscalls_enter_open_args { 11 unsigned long long unused; 12 long syscall_nr; 13 long filename_ptr; 14 long flags; 15 long mode; 16 }; 17 18 struct syscalls_exit_open_args { 19 unsigned long long unused; 20 long syscall_nr; 21 long ret; 22 }; 23 24 struct bpf_map_def SEC("maps") enter_open_map = { 25 .type = BPF_MAP_TYPE_ARRAY, 26 .key_size = sizeof(u32), 27 .value_size = sizeof(u32), 28 .max_entries = 1, 29 }; 30 31 struct bpf_map_def SEC("maps") exit_open_map = { 32 .type = BPF_MAP_TYPE_ARRAY, 33 .key_size = sizeof(u32), 34 .value_size = sizeof(u32), 35 .max_entries = 1, 36 }; 37 38 static __always_inline void count(void *map) 39 { 40 u32 key = 0; 41 u32 *value, init_val = 1; 42 43 value = bpf_map_lookup_elem(map, &key); 44 if (value) 45 *value += 1; 46 else 47 bpf_map_update_elem(map, &key, &init_val, BPF_NOEXIST); 48 } 49 50 SEC("tracepoint/syscalls/sys_enter_open") 51 int trace_enter_open(struct syscalls_enter_open_args *ctx) 52 { 53 count((void *)&enter_open_map); 54 return 0; 55 } 56 57 SEC("tracepoint/syscalls/sys_exit_open") 58 int trace_enter_exit(struct syscalls_exit_open_args *ctx) 59 { 60 count((void *)&exit_open_map); 61 return 0; 62 } 63