linuxdebug/tools/testing/selftests/bpf/progs/test_perf_buffer.c

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2024-07-16 15:50:57 +02:00
// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2019 Facebook
#include <linux/ptrace.h>
#include <linux/bpf.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
struct {
__uint(type, BPF_MAP_TYPE_ARRAY);
__type(key, int);
__type(value, int);
__uint(max_entries, 1);
} my_pid_map SEC(".maps");
struct {
__uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
__type(key, int);
__type(value, int);
} perf_buf_map SEC(".maps");
SEC("tp/raw_syscalls/sys_enter")
int handle_sys_enter(void *ctx)
{
int zero = 0, *my_pid, cur_pid;
int cpu = bpf_get_smp_processor_id();
my_pid = bpf_map_lookup_elem(&my_pid_map, &zero);
if (!my_pid)
return 1;
cur_pid = bpf_get_current_pid_tgid() >> 32;
if (cur_pid != *my_pid)
return 1;
bpf_perf_event_output(ctx, &perf_buf_map, BPF_F_CURRENT_CPU,
&cpu, sizeof(cpu));
return 1;
}
char _license[] SEC("license") = "GPL";