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9811e353 AS |
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 <linux/ptrace.h> | |
8 | #include <linux/version.h> | |
9 | #include <uapi/linux/bpf.h> | |
10 | #include "bpf_helpers.h" | |
11 | ||
12 | struct pair { | |
13 | u64 val; | |
14 | u64 ip; | |
15 | }; | |
16 | ||
17 | struct 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 | */ | |
27 | SEC("kprobe/kmem_cache_free") | |
28 | int bpf_prog1(struct pt_regs *ctx) | |
29 | { | |
d912557b | 30 | long ptr = PT_REGS_PARM2(ctx); |
9811e353 AS |
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 | { | |
d912557b | 39 | long ptr = PT_REGS_RC(ctx); |
9811e353 AS |
40 | long ip = 0; |
41 | ||
42 | /* get ip address of kmem_cache_alloc_node() caller */ | |
138d6153 | 43 | BPF_KRETPROBE_READ_RET_IP(ip, ctx); |
9811e353 AS |
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; |