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 #if !defined(__aarch64__)
   8 struct syscalls_enter_open_args {
   9         unsigned long long unused;
  10         long syscall_nr;
  11         long filename_ptr;
  12         long flags;
  13         long mode;
  14 };
  15 #endif
  16
  17 struct syscalls_exit_open_args {
  18         unsigned long long unused;
  19         long syscall_nr;
  20         long ret;
  21 };
  22
  23 struct syscalls_enter_open_at_args {
  24         unsigned long long unused;
  25         long syscall_nr;
  26         long long dfd;
  27         long filename_ptr;
  28         long flags;
  29         long mode;
  30 };
  31
  32 struct {
  33         __uint(type, BPF_MAP_TYPE_ARRAY);
  34         __type(key, u32);
  35         __type(value, u32);
  36         __uint(max_entries, 1);
  37 } enter_open_map SEC(".maps");
  38
  39 struct {
  40         __uint(type, BPF_MAP_TYPE_ARRAY);
  41         __type(key, u32);
  42         __type(value, u32);
  43         __uint(max_entries, 1);
  44 } exit_open_map SEC(".maps");
  45
  46 static __always_inline void count(void *map)
  47 {
  48         u32 key = 0;
  49         u32 *value, init_val = 1;
  50
  51         value = bpf_map_lookup_elem(map, &key);
  52         if (value)
  53                 *value += 1;
  54         else
  55                 bpf_map_update_elem(map, &key, &init_val, BPF_NOEXIST);
  56 }
  57
  58 #if !defined(__aarch64__)
  59 SEC("tracepoint/syscalls/sys_enter_open")
  60 int trace_enter_open(struct syscalls_enter_open_args *ctx)
  61 {
  62         count(&enter_open_map);
  63         return 0;
  64 }
  65 #endif
  66
  67 SEC("tracepoint/syscalls/sys_enter_openat")
  68 int trace_enter_open_at(struct syscalls_enter_open_at_args *ctx)
  69 {
  70         count(&enter_open_map);
  71         return 0;
  72 }
  73
  74 SEC("tracepoint/syscalls/sys_enter_openat2")
  75 int trace_enter_open_at2(struct syscalls_enter_open_at_args *ctx)
  76 {
  77         count(&enter_open_map);
  78         return 0;
  79 }
  80
  81 #if !defined(__aarch64__)
  82 SEC("tracepoint/syscalls/sys_exit_open")
  83 int trace_enter_exit(struct syscalls_exit_open_args *ctx)
  84 {
  85         count(&exit_open_map);
  86         return 0;
  87 }
  88 #endif
  89
  90 SEC("tracepoint/syscalls/sys_exit_openat")
  91 int trace_enter_exit_at(struct syscalls_exit_open_args *ctx)
  92 {
  93         count(&exit_open_map);
  94         return 0;
  95 }
  96
  97 SEC("tracepoint/syscalls/sys_exit_openat2")
  98 int trace_enter_exit_at2(struct syscalls_exit_open_args *ctx)
  99 {
 100         count(&exit_open_map);
 101         return 0;
 102 }