// SPDX-License-Identifier: GPL-2.0 /* Copyright (c) 2020 Facebook */ #include "vmlinux.h" #include <bpf/bpf_helpers.h> extern const struct rq runqueues __ksym; /* struct type global var. */ extern const int bpf_prog_active __ksym; /* int type global var. */ SEC("raw_tp/sys_enter") int handler(const void *ctx) { struct rq *rq; int *active; __u32 cpu; cpu = bpf_get_smp_processor_id(); rq = (struct rq *)bpf_per_cpu_ptr(&runqueues, cpu); active = (int *)bpf_per_cpu_ptr(&bpf_prog_active, cpu); if (active) { /* READ_ONCE */ *(volatile int *)active; /* !rq has not been tested, so verifier should reject. */ *(volatile int *)(&rq->cpu); } return 0; } char _license[] SEC("license") = "GPL";