tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1#include <linux/ptrace.h>
2#include <linux/version.h>
3#include <uapi/linux/bpf.h>
4#include "bpf_helpers.h"
5
6struct bpf_map_def SEC("maps") counters = {
7 .type = BPF_MAP_TYPE_PERF_EVENT_ARRAY,
8 .key_size = sizeof(int),
9 .value_size = sizeof(u32),
10 .max_entries = 64,
11};
12struct bpf_map_def SEC("maps") values = {
13 .type = BPF_MAP_TYPE_HASH,
14 .key_size = sizeof(int),
15 .value_size = sizeof(u64),
16 .max_entries = 64,
17};
18struct bpf_map_def SEC("maps") values2 = {
19 .type = BPF_MAP_TYPE_HASH,
20 .key_size = sizeof(int),
21 .value_size = sizeof(struct bpf_perf_event_value),
22 .max_entries = 64,
23};
24
25SEC("kprobe/htab_map_get_next_key")
26int bpf_prog1(struct pt_regs *ctx)
27{
28 u32 key = bpf_get_smp_processor_id();
29 u64 count, *val;
30 s64 error;
31
32 count = bpf_perf_event_read(&counters, key);
33 error = (s64)count;
34 if (error <= -2 && error >= -22)
35 return 0;
36
37 val = bpf_map_lookup_elem(&values, &key);
38 if (val)
39 *val = count;
40 else
41 bpf_map_update_elem(&values, &key, &count, BPF_NOEXIST);
42
43 return 0;
44}
45
46SEC("kprobe/htab_map_lookup_elem")
47int bpf_prog2(struct pt_regs *ctx)
48{
49 u32 key = bpf_get_smp_processor_id();
50 struct bpf_perf_event_value *val, buf;
51 int error;
52
53 error = bpf_perf_event_read_value(&counters, key, &buf, sizeof(buf));
54 if (error)
55 return 0;
56
57 val = bpf_map_lookup_elem(&values2, &key);
58 if (val)
59 *val = buf;
60 else
61 bpf_map_update_elem(&values2, &key, &buf, BPF_NOEXIST);
62
63 return 0;
64}
65
66char _license[] SEC("license") = "GPL";
67u32 _version SEC("version") = LINUX_VERSION_CODE;