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