/* 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/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;