tools/testing/selftests/bpf/progs/cgrp_ls_tp_btf.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */
   3
   4 #include "vmlinux.h"
   5 #include <bpf/bpf_helpers.h>
   6 #include <bpf/bpf_tracing.h>
   7
   8 char _license[] SEC("license") = "GPL";
   9
  10 struct {
  11         __uint(type, BPF_MAP_TYPE_CGRP_STORAGE);
  12         __uint(map_flags, BPF_F_NO_PREALLOC);
  13         __type(key, int);
  14         __type(value, long);
  15 } map_a SEC(".maps");
  16
  17 struct {
  18         __uint(type, BPF_MAP_TYPE_CGRP_STORAGE);
  19         __uint(map_flags, BPF_F_NO_PREALLOC);
  20         __type(key, int);
  21         __type(value, long);
  22 } map_b SEC(".maps");
  23
  24 #define MAGIC_VALUE 0xabcd1234
  25
  26 pid_t target_pid = 0;
  27 int mismatch_cnt = 0;
  28 int enter_cnt = 0;
  29 int exit_cnt = 0;
  30
  31 SEC("tp_btf/sys_enter")
  32 int BPF_PROG(on_enter, struct pt_regs *regs, long id)
  33 {
  34         struct task_struct *task;
  35         long *ptr;
  36         int err;
  37
  38         task = bpf_get_current_task_btf();
  39         if (task->pid != target_pid)
  40                 return 0;
  41
  42         /* populate value 0 */
  43         ptr = bpf_cgrp_storage_get(&map_a, task->cgroups->dfl_cgrp, 0,
  44                                    BPF_LOCAL_STORAGE_GET_F_CREATE);
  45         if (!ptr)
  46                 return 0;
  47
  48         /* delete value 0 */
  49         err = bpf_cgrp_storage_delete(&map_a, task->cgroups->dfl_cgrp);
  50         if (err)
  51                 return 0;
  52
  53         /* value is not available */
  54         ptr = bpf_cgrp_storage_get(&map_a, task->cgroups->dfl_cgrp, 0, 0);
  55         if (ptr)
  56                 return 0;
  57
  58         /* re-populate the value */
  59         ptr = bpf_cgrp_storage_get(&map_a, task->cgroups->dfl_cgrp, 0,
  60                                    BPF_LOCAL_STORAGE_GET_F_CREATE);
  61         if (!ptr)
  62                 return 0;
  63         __sync_fetch_and_add(&enter_cnt, 1);
  64         *ptr = MAGIC_VALUE + enter_cnt;
  65
  66         return 0;
  67 }
  68
  69 SEC("tp_btf/sys_exit")
  70 int BPF_PROG(on_exit, struct pt_regs *regs, long id)
  71 {
  72         struct task_struct *task;
  73         long *ptr;
  74
  75         task = bpf_get_current_task_btf();
  76         if (task->pid != target_pid)
  77                 return 0;
  78
  79         ptr = bpf_cgrp_storage_get(&map_a, task->cgroups->dfl_cgrp, 0,
  80                                    BPF_LOCAL_STORAGE_GET_F_CREATE);
  81         if (!ptr)
  82                 return 0;
  83
  84         __sync_fetch_and_add(&exit_cnt, 1);
  85         if (*ptr != MAGIC_VALUE + exit_cnt)
  86                 __sync_fetch_and_add(&mismatch_cnt, 1);
  87         return 0;
  88 }