1 | /* 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 "vmlinux.h" |
8 | #include <linux/version.h> |
9 | #include <bpf/bpf_helpers.h> |
10 | #include <bpf/bpf_tracing.h> |
11 | |
12 | struct pair { |
13 | u64 val; |
14 | u64 ip; |
15 | }; |
16 | |
17 | struct { |
18 | __uint(type, BPF_MAP_TYPE_HASH); |
19 | __type(key, long); |
20 | __type(value, struct pair); |
21 | __uint(max_entries, 1000000); |
22 | } my_map SEC(".maps" ); |
23 | |
24 | /* kprobe is NOT a stable ABI. If kernel internals change this bpf+kprobe |
25 | * example will no longer be meaningful |
26 | */ |
27 | SEC("kprobe/kmem_cache_free" ) |
28 | int bpf_prog1(struct pt_regs *ctx) |
29 | { |
30 | long ptr = PT_REGS_PARM2(ctx); |
31 | |
32 | bpf_map_delete_elem(&my_map, &ptr); |
33 | return 0; |
34 | } |
35 | |
36 | SEC("kretprobe/kmem_cache_alloc_node" ) |
37 | int bpf_prog2(struct pt_regs *ctx) |
38 | { |
39 | long ptr = PT_REGS_RC(ctx); |
40 | long ip = 0; |
41 | |
42 | /* get ip address of kmem_cache_alloc_node() caller */ |
43 | BPF_KRETPROBE_READ_RET_IP(ip, ctx); |
44 | |
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 | } |
53 | char _license[] SEC("license" ) = "GPL" ; |
54 | u32 _version SEC("version" ) = LINUX_VERSION_CODE; |
55 | |