test_current_task_under_cgroup_kern.c (1139B)
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/bpf_helpers.h> 12#include <uapi/linux/utsname.h> 13#include "trace_common.h" 14 15struct { 16 __uint(type, BPF_MAP_TYPE_CGROUP_ARRAY); 17 __uint(key_size, sizeof(u32)); 18 __uint(value_size, sizeof(u32)); 19 __uint(max_entries, 1); 20} cgroup_map SEC(".maps"); 21 22struct { 23 __uint(type, BPF_MAP_TYPE_ARRAY); 24 __type(key, u32); 25 __type(value, u64); 26 __uint(max_entries, 1); 27} perf_map SEC(".maps"); 28 29/* Writes the last PID that called sync to a map at index 0 */ 30SEC("kprobe/" SYSCALL(sys_sync)) 31int bpf_prog1(struct pt_regs *ctx) 32{ 33 u64 pid = bpf_get_current_pid_tgid(); 34 int idx = 0; 35 36 if (!bpf_current_task_under_cgroup(&cgroup_map, 0)) 37 return 0; 38 39 bpf_map_update_elem(&perf_map, &idx, &pid, BPF_ANY); 40 return 0; 41} 42 43char _license[] SEC("license") = "GPL"; 44u32 _version SEC("version") = LINUX_VERSION_CODE;