1 /* Copyright (c) 2015 PLUMgrid, http://plumgrid.com
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.
7 #include <linux/ptrace.h>
8 #include <linux/version.h>
9 #include <uapi/linux/bpf.h>
10 #include <bpf/bpf_helpers.h>
11 #include <bpf/bpf_tracing.h>
19 __uint(type, BPF_MAP_TYPE_HASH);
21 __type(value, struct pair);
22 __uint(max_entries, 1000000);
23 } my_map SEC(".maps");
25 /* kprobe is NOT a stable ABI. If kernel internals change this bpf+kprobe
26 * example will no longer be meaningful
28 SEC("kprobe/kmem_cache_free")
29 int bpf_prog1(struct pt_regs *ctx)
31 long ptr = PT_REGS_PARM2(ctx);
33 bpf_map_delete_elem(&my_map, &ptr);
37 SEC("kretprobe/kmem_cache_alloc_node")
38 int bpf_prog2(struct pt_regs *ctx)
40 long ptr = PT_REGS_RC(ctx);
43 /* get ip address of kmem_cache_alloc_node() caller */
44 BPF_KRETPROBE_READ_RET_IP(ip, ctx);
47 .val = bpf_ktime_get_ns(),
51 bpf_map_update_elem(&my_map, &ptr, &v, BPF_ANY);
54 char _license[] SEC("license") = "GPL";
55 u32 _version SEC("version") = LINUX_VERSION_CODE;