samples/bpf/syscall_tp_kern.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /* Copyright (c) 2017 Facebook
   3  */
   4 #include <uapi/linux/bpf.h>
   5 #include <bpf/bpf_helpers.h>
   6
   7 struct syscalls_enter_open_args {
   8         unsigned long long unused;
   9         long syscall_nr;
  10         long filename_ptr;
  11         long flags;
  12         long mode;
  13 };
  14
  15 struct syscalls_exit_open_args {
  16         unsigned long long unused;
  17         long syscall_nr;
  18         long ret;
  19 };
  20
  21 struct {
  22         __uint(type, BPF_MAP_TYPE_ARRAY);
  23         __type(key, u32);
  24         __type(value, u32);
  25         __uint(max_entries, 1);
  26 } enter_open_map SEC(".maps");
  27
  28 struct {
  29         __uint(type, BPF_MAP_TYPE_ARRAY);
  30         __type(key, u32);
  31         __type(value, u32);
  32         __uint(max_entries, 1);
  33 } exit_open_map SEC(".maps");
  34
  35 static __always_inline void count(void *map)
  36 {
  37         u32 key = 0;
  38         u32 *value, init_val = 1;
  39
  40         value = bpf_map_lookup_elem(map, &key);
  41         if (value)
  42                 *value += 1;
  43         else
  44                 bpf_map_update_elem(map, &key, &init_val, BPF_NOEXIST);
  45 }
  46
  47 #if !defined(__aarch64__)
  48 SEC("tracepoint/syscalls/sys_enter_open")
  49 int trace_enter_open(struct syscalls_enter_open_args *ctx)
  50 {
  51         count(&enter_open_map);
  52         return 0;
  53 }
  54 #endif
  55
  56 SEC("tracepoint/syscalls/sys_enter_openat")
  57 int trace_enter_open_at(struct syscalls_enter_open_args *ctx)
  58 {
  59         count(&enter_open_map);
  60         return 0;
  61 }
  62
  63 SEC("tracepoint/syscalls/sys_enter_openat2")
  64 int trace_enter_open_at2(struct syscalls_enter_open_args *ctx)
  65 {
  66         count(&enter_open_map);
  67         return 0;
  68 }
  69
  70 #if !defined(__aarch64__)
  71 SEC("tracepoint/syscalls/sys_exit_open")
  72 int trace_enter_exit(struct syscalls_exit_open_args *ctx)
  73 {
  74         count(&exit_open_map);
  75         return 0;
  76 }
  77 #endif
  78
  79 SEC("tracepoint/syscalls/sys_exit_openat")
  80 int trace_enter_exit_at(struct syscalls_exit_open_args *ctx)
  81 {
  82         count(&exit_open_map);
  83         return 0;
  84 }
  85
  86 SEC("tracepoint/syscalls/sys_exit_openat2")
  87 int trace_enter_exit_at2(struct syscalls_exit_open_args *ctx)
  88 {
  89         count(&exit_open_map);
  90         return 0;
  91 }