blob: ac4671420cf15949c4087b8c2847c69978646650 [file] [log] [blame]
Alexei Starovoitov9811e352015-03-25 12:49:26 -07001/* Copyright (c) 2015 PLUMgrid, http://plumgrid.com
2 *
3 * This program is free software; you can redistribute it and/or
4 * modify it under the terms of version 2 of the GNU General Public
5 * License as published by the Free Software Foundation.
6 */
7#include <linux/ptrace.h>
8#include <linux/version.h>
9#include <uapi/linux/bpf.h>
10#include "bpf_helpers.h"
11
12struct pair {
13 u64 val;
14 u64 ip;
15};
16
17struct bpf_map_def SEC("maps") my_map = {
18 .type = BPF_MAP_TYPE_HASH,
19 .key_size = sizeof(long),
20 .value_size = sizeof(struct pair),
21 .max_entries = 1000000,
22};
23
24/* kprobe is NOT a stable ABI. If kernel internals change this bpf+kprobe
25 * example will no longer be meaningful
26 */
27SEC("kprobe/kmem_cache_free")
28int bpf_prog1(struct pt_regs *ctx)
29{
Michael Holzheud9125572015-07-06 16:20:07 +020030 long ptr = PT_REGS_PARM2(ctx);
Alexei Starovoitov9811e352015-03-25 12:49:26 -070031
32 bpf_map_delete_elem(&my_map, &ptr);
33 return 0;
34}
35
36SEC("kretprobe/kmem_cache_alloc_node")
37int bpf_prog2(struct pt_regs *ctx)
38{
Michael Holzheud9125572015-07-06 16:20:07 +020039 long ptr = PT_REGS_RC(ctx);
Alexei Starovoitov9811e352015-03-25 12:49:26 -070040 long ip = 0;
41
42 /* get ip address of kmem_cache_alloc_node() caller */
Michael Holzheud9125572015-07-06 16:20:07 +020043 bpf_probe_read(&ip, sizeof(ip), (void *)(PT_REGS_FP(ctx) + sizeof(ip)));
Alexei Starovoitov9811e352015-03-25 12:49:26 -070044
45 struct pair v = {
46 .val = bpf_ktime_get_ns(),
47 .ip = ip,
48 };
49
50 bpf_map_update_elem(&my_map, &ptr, &v, BPF_ANY);
51 return 0;
52}
53char _license[] SEC("license") = "GPL";
54u32 _version SEC("version") = LINUX_VERSION_CODE;