Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0
2#include <vmlinux.h>
3#include <bpf/bpf_helpers.h>
4#include <bpf/bpf_tracing.h>
5#include "bpf_experimental.h"
6
7char _license[] SEC("license") = "GPL";
8
9#define CLOCK_MONOTONIC 1
10
11int preempt_count;
12int in_interrupt;
13int in_interrupt_cb;
14
15struct elem {
16 struct bpf_timer t;
17};
18
19struct {
20 __uint(type, BPF_MAP_TYPE_ARRAY);
21 __uint(max_entries, 1);
22 __type(key, int);
23 __type(value, struct elem);
24} array SEC(".maps");
25
26static int timer_in_interrupt(void *map, int *key, struct bpf_timer *timer)
27{
28 preempt_count = get_preempt_count();
29 in_interrupt_cb = bpf_in_interrupt();
30 return 0;
31}
32
33SEC("fentry/bpf_fentry_test1")
34int BPF_PROG(test_timer_interrupt)
35{
36 struct bpf_timer *timer;
37 int key = 0;
38
39 timer = bpf_map_lookup_elem(&array, &key);
40 if (!timer)
41 return 0;
42
43 in_interrupt = bpf_in_interrupt();
44 bpf_timer_init(timer, &array, CLOCK_MONOTONIC);
45 bpf_timer_set_callback(timer, timer_in_interrupt);
46 bpf_timer_start(timer, 0, 0);
47 return 0;
48}