Sargun Dhillon | 9e6e60e | 2016-08-12 08:57:04 -0700 | [diff] [blame] | 1 | /* Copyright (c) 2016 Sargun Dhillon <sargun@sargun.me> |
| 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 | |
| 8 | #include <linux/ptrace.h> |
| 9 | #include <uapi/linux/bpf.h> |
| 10 | #include <linux/version.h> |
| 11 | #include "bpf_helpers.h" |
| 12 | #include <uapi/linux/utsname.h> |
| 13 | |
| 14 | struct bpf_map_def SEC("maps") cgroup_map = { |
| 15 | .type = BPF_MAP_TYPE_CGROUP_ARRAY, |
| 16 | .key_size = sizeof(u32), |
| 17 | .value_size = sizeof(u32), |
| 18 | .max_entries = 1, |
| 19 | }; |
| 20 | |
| 21 | struct bpf_map_def SEC("maps") perf_map = { |
| 22 | .type = BPF_MAP_TYPE_ARRAY, |
| 23 | .key_size = sizeof(u32), |
| 24 | .value_size = sizeof(u64), |
| 25 | .max_entries = 1, |
| 26 | }; |
| 27 | |
| 28 | /* Writes the last PID that called sync to a map at index 0 */ |
| 29 | SEC("kprobe/sys_sync") |
| 30 | int bpf_prog1(struct pt_regs *ctx) |
| 31 | { |
| 32 | u64 pid = bpf_get_current_pid_tgid(); |
| 33 | int idx = 0; |
| 34 | |
| 35 | if (!bpf_current_task_under_cgroup(&cgroup_map, 0)) |
| 36 | return 0; |
| 37 | |
| 38 | bpf_map_update_elem(&perf_map, &idx, &pid, BPF_ANY); |
| 39 | return 0; |
| 40 | } |
| 41 | |
| 42 | char _license[] SEC("license") = "GPL"; |
| 43 | u32 _version SEC("version") = LINUX_VERSION_CODE; |