test_current_task_under_cgroup_kern.c
1.08 KB
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/* Copyright (c) 2016 Sargun Dhillon <sargun@sargun.me>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
* License as published by the Free Software Foundation.
*/
#include <linux/ptrace.h>
#include <uapi/linux/bpf.h>
#include <linux/version.h>
#include "bpf_helpers.h"
#include <uapi/linux/utsname.h>
struct bpf_map_def SEC("maps") cgroup_map = {
.type = BPF_MAP_TYPE_CGROUP_ARRAY,
.key_size = sizeof(u32),
.value_size = sizeof(u32),
.max_entries = 1,
};
struct bpf_map_def SEC("maps") perf_map = {
.type = BPF_MAP_TYPE_ARRAY,
.key_size = sizeof(u32),
.value_size = sizeof(u64),
.max_entries = 1,
};
/* Writes the last PID that called sync to a map at index 0 */
SEC("kprobe/sys_sync")
int bpf_prog1(struct pt_regs *ctx)
{
u64 pid = bpf_get_current_pid_tgid();
int idx = 0;
if (!bpf_current_task_under_cgroup(&cgroup_map, 0))
return 0;
bpf_map_update_elem(&perf_map, &idx, &pid, BPF_ANY);
return 0;
}
char _license[] SEC("license") = "GPL";
u32 _version SEC("version") = LINUX_VERSION_CODE;