/* SPDX-License-Identifier: GPL-2.0 */ | |
/* Copyright (c) 2021 Hengqi Chen */ | |
#include "vmlinux.h" | |
#include <bpf/bpf_helpers.h> | |
#include <bpf/bpf_tracing.h> | |
const volatile pid_t my_pid = 0; | |
int value = 0; | |
SEC("raw_tp/sys_enter") | |
int tailcall_1(void *ctx) | |
{ | |
value = 42; | |
return 0; | |
} | |
struct { | |
__uint(type, BPF_MAP_TYPE_PROG_ARRAY); | |
__uint(max_entries, 2); | |
__uint(key_size, sizeof(__u32)); | |
__array(values, int (void *)); | |
} prog_array_init SEC(".maps") = { | |
.values = { | |
[1] = (void *)&tailcall_1, | |
}, | |
}; | |
SEC("raw_tp/sys_enter") | |
int entry(void *ctx) | |
{ | |
pid_t pid = bpf_get_current_pid_tgid() >> 32; | |
if (pid != my_pid) | |
return 0; | |
bpf_tail_call(ctx, &prog_array_init, 1); | |
return 0; | |
} |