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// 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";
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