| 1 | // SPDX-License-Identifier: GPL-2.0 |
|---|
| 2 | /* Copyright (C) 2022. Huawei Technologies Co., Ltd */ |
|---|
| 3 | #include "vmlinux.h" |
|---|
| 4 | #include <bpf/bpf_helpers.h> |
|---|
| 5 | #include <bpf/bpf_tracing.h> |
|---|
| 6 | |
|---|
| 7 | extern bool CONFIG_PREEMPT __kconfig __weak; |
|---|
| 8 | extern const int bpf_task_storage_busy __ksym; |
|---|
| 9 | |
|---|
| 10 | char _license[] SEC("license" ) = "GPL" ; |
|---|
| 11 | |
|---|
| 12 | int pid = 0; |
|---|
| 13 | int busy = 0; |
|---|
| 14 | |
|---|
| 15 | struct { |
|---|
| 16 | __uint(type, BPF_MAP_TYPE_TASK_STORAGE); |
|---|
| 17 | __uint(map_flags, BPF_F_NO_PREALLOC); |
|---|
| 18 | __type(key, int); |
|---|
| 19 | __type(value, long); |
|---|
| 20 | } task SEC(".maps" ); |
|---|
| 21 | |
|---|
| 22 | SEC("raw_tp/sys_enter" ) |
|---|
| 23 | int BPF_PROG(read_bpf_task_storage_busy) |
|---|
| 24 | { |
|---|
| 25 | int *value; |
|---|
| 26 | |
|---|
| 27 | if (!CONFIG_PREEMPT) |
|---|
| 28 | return 0; |
|---|
| 29 | |
|---|
| 30 | if (bpf_get_current_pid_tgid() >> 32 != pid) |
|---|
| 31 | return 0; |
|---|
| 32 | |
|---|
| 33 | value = bpf_this_cpu_ptr(&bpf_task_storage_busy); |
|---|
| 34 | if (value) |
|---|
| 35 | busy = *value; |
|---|
| 36 | |
|---|
| 37 | return 0; |
|---|
| 38 | } |
|---|
| 39 | |
|---|
