| // SPDX-License-Identifier: GPL-2.0 |
| // Copyright (c) 2020 Facebook |
| #include <linux/bpf.h> |
| #include <bpf/bpf_helpers.h> |
| #include <bpf/bpf_core_read.h> |
| |
| struct task_struct { |
| int tgid; |
| } __attribute__((preserve_access_index)); |
| |
| struct { |
| __uint(type, BPF_MAP_TYPE_ARRAY); |
| __uint(max_entries, 1); |
| __type(key, int); |
| __type(value, int); |
| } exp_tgid_map SEC(".maps"); |
| |
| struct { |
| __uint(type, BPF_MAP_TYPE_ARRAY); |
| __uint(max_entries, 1); |
| __type(key, int); |
| __type(value, int); |
| } results SEC(".maps"); |
| |
| SEC("tp/raw_syscalls/sys_enter") |
| int handle_sys_enter(void *ctx) |
| { |
| struct task_struct *task = (void *)bpf_get_current_task(); |
| int tgid = BPF_CORE_READ(task, tgid); |
| int zero = 0; |
| int real_tgid = bpf_get_current_pid_tgid() >> 32; |
| int *exp_tgid = bpf_map_lookup_elem(&exp_tgid_map, &zero); |
| |
| /* only pass through sys_enters from test process */ |
| if (!exp_tgid || *exp_tgid != real_tgid) |
| return 0; |
| |
| bpf_map_update_elem(&results, &zero, &tgid, 0); |
| |
| return 0; |
| } |
| |
| char _license[] SEC("license") = "GPL"; |