55 lines
1.3 KiB
C
55 lines
1.3 KiB
C
/* Copyright (c) 2015 PLUMgrid, http://plumgrid.com
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of version 2 of the GNU General Public
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* License as published by the Free Software Foundation.
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*/
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#include <linux/ptrace.h>
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#include <linux/version.h>
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#include <uapi/linux/bpf.h>
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#include "bpf_helpers.h"
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struct pair {
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u64 val;
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u64 ip;
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};
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struct bpf_map_def SEC("maps") my_map = {
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.type = BPF_MAP_TYPE_HASH,
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.key_size = sizeof(long),
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.value_size = sizeof(struct pair),
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.max_entries = 1000000,
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};
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/* kprobe is NOT a stable ABI. If kernel internals change this bpf+kprobe
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* example will no longer be meaningful
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*/
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SEC("kprobe/kmem_cache_free")
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int bpf_prog1(struct pt_regs *ctx)
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{
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long ptr = PT_REGS_PARM2(ctx);
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bpf_map_delete_elem(&my_map, &ptr);
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return 0;
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}
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SEC("kretprobe/kmem_cache_alloc_node")
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int bpf_prog2(struct pt_regs *ctx)
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{
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long ptr = PT_REGS_RC(ctx);
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long ip = 0;
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/* get ip address of kmem_cache_alloc_node() caller */
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bpf_probe_read(&ip, sizeof(ip), (void *)(PT_REGS_FP(ctx) + sizeof(ip)));
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struct pair v = {
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.val = bpf_ktime_get_ns(),
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.ip = ip,
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};
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bpf_map_update_elem(&my_map, &ptr, &v, BPF_ANY);
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return 0;
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}
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char _license[] SEC("license") = "GPL";
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u32 _version SEC("version") = LINUX_VERSION_CODE;
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