1*4882a593Smuzhiyun /* Copyright (c) 2015 PLUMgrid, http://plumgrid.com
2*4882a593Smuzhiyun *
3*4882a593Smuzhiyun * This program is free software; you can redistribute it and/or
4*4882a593Smuzhiyun * modify it under the terms of version 2 of the GNU General Public
5*4882a593Smuzhiyun * License as published by the Free Software Foundation.
6*4882a593Smuzhiyun */
7*4882a593Smuzhiyun #include <linux/ptrace.h>
8*4882a593Smuzhiyun #include <linux/version.h>
9*4882a593Smuzhiyun #include <uapi/linux/bpf.h>
10*4882a593Smuzhiyun #include <bpf/bpf_helpers.h>
11*4882a593Smuzhiyun #include <bpf/bpf_tracing.h>
12*4882a593Smuzhiyun
13*4882a593Smuzhiyun struct pair {
14*4882a593Smuzhiyun u64 val;
15*4882a593Smuzhiyun u64 ip;
16*4882a593Smuzhiyun };
17*4882a593Smuzhiyun
18*4882a593Smuzhiyun struct {
19*4882a593Smuzhiyun __uint(type, BPF_MAP_TYPE_HASH);
20*4882a593Smuzhiyun __type(key, long);
21*4882a593Smuzhiyun __type(value, struct pair);
22*4882a593Smuzhiyun __uint(max_entries, 1000000);
23*4882a593Smuzhiyun } my_map SEC(".maps");
24*4882a593Smuzhiyun
25*4882a593Smuzhiyun /* kprobe is NOT a stable ABI. If kernel internals change this bpf+kprobe
26*4882a593Smuzhiyun * example will no longer be meaningful
27*4882a593Smuzhiyun */
28*4882a593Smuzhiyun SEC("kprobe/kmem_cache_free")
bpf_prog1(struct pt_regs * ctx)29*4882a593Smuzhiyun int bpf_prog1(struct pt_regs *ctx)
30*4882a593Smuzhiyun {
31*4882a593Smuzhiyun long ptr = PT_REGS_PARM2(ctx);
32*4882a593Smuzhiyun
33*4882a593Smuzhiyun bpf_map_delete_elem(&my_map, &ptr);
34*4882a593Smuzhiyun return 0;
35*4882a593Smuzhiyun }
36*4882a593Smuzhiyun
37*4882a593Smuzhiyun SEC("kretprobe/kmem_cache_alloc_node")
bpf_prog2(struct pt_regs * ctx)38*4882a593Smuzhiyun int bpf_prog2(struct pt_regs *ctx)
39*4882a593Smuzhiyun {
40*4882a593Smuzhiyun long ptr = PT_REGS_RC(ctx);
41*4882a593Smuzhiyun long ip = 0;
42*4882a593Smuzhiyun
43*4882a593Smuzhiyun /* get ip address of kmem_cache_alloc_node() caller */
44*4882a593Smuzhiyun BPF_KRETPROBE_READ_RET_IP(ip, ctx);
45*4882a593Smuzhiyun
46*4882a593Smuzhiyun struct pair v = {
47*4882a593Smuzhiyun .val = bpf_ktime_get_ns(),
48*4882a593Smuzhiyun .ip = ip,
49*4882a593Smuzhiyun };
50*4882a593Smuzhiyun
51*4882a593Smuzhiyun bpf_map_update_elem(&my_map, &ptr, &v, BPF_ANY);
52*4882a593Smuzhiyun return 0;
53*4882a593Smuzhiyun }
54*4882a593Smuzhiyun char _license[] SEC("license") = "GPL";
55*4882a593Smuzhiyun u32 _version SEC("version") = LINUX_VERSION_CODE;
56