| // SPDX-License-Identifier: GPL-2.0 |
| // Copyright (c) 2020 Facebook |
| |
| #include "vmlinux.h" |
| #include <bpf/bpf_helpers.h> |
| #include <bpf/bpf_core_read.h> |
| |
| char _license[] SEC("license") = "GPL"; |
| |
| /* shuffled layout for relocatable (CO-RE) reads */ |
| struct callback_head___shuffled { |
| void (*func)(struct callback_head___shuffled *head); |
| struct callback_head___shuffled *next; |
| }; |
| |
| struct callback_head k_probe_in = {}; |
| struct callback_head___shuffled k_core_in = {}; |
| |
| struct callback_head *u_probe_in = 0; |
| struct callback_head___shuffled *u_core_in = 0; |
| |
| long k_probe_out = 0; |
| long u_probe_out = 0; |
| |
| long k_core_out = 0; |
| long u_core_out = 0; |
| |
| int my_pid = 0; |
| |
| SEC("raw_tracepoint/sys_enter") |
| int handler(void *ctx) |
| { |
| int pid = bpf_get_current_pid_tgid() >> 32; |
| |
| if (my_pid != pid) |
| return 0; |
| |
| /* next pointers for kernel address space have to be initialized from |
| * BPF side, user-space mmaped addresses are stil user-space addresses |
| */ |
| k_probe_in.next = &k_probe_in; |
| __builtin_preserve_access_index(({k_core_in.next = &k_core_in;})); |
| |
| k_probe_out = (long)BPF_PROBE_READ(&k_probe_in, next, next, func); |
| k_core_out = (long)BPF_CORE_READ(&k_core_in, next, next, func); |
| u_probe_out = (long)BPF_PROBE_READ_USER(u_probe_in, next, next, func); |
| u_core_out = (long)BPF_CORE_READ_USER(u_core_in, next, next, func); |
| |
| return 0; |
| } |