// 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; }